nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2008 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "lang_features.h"
  38 #include "walk_statements.h"
  39 #include "warning.h"
  40 #include "adt/bitfiddle.h"
  41 #include "adt/error.h"
  42 #include "adt/array.h"
  43
  44 //#define PRINT_TOKENS
  45 #define MAX_LOOKAHEAD 1
  46
  47 typedef struct {
  48         entity_t           *old_entity;
  49         symbol_t           *symbol;
  50         entity_namespace_t  namespc;
  51 } stack_entry_t;
  52
  53 typedef struct argument_list_t argument_list_t;
  54 struct argument_list_t {
  55         long              argument;
  56         argument_list_t  *next;
  57 };
  58
  59 typedef struct gnu_attribute_t gnu_attribute_t;
  60 struct gnu_attribute_t {
  61         gnu_attribute_kind_t kind;          /**< The kind of the GNU attribute. */
  62         gnu_attribute_t     *next;
  63         bool                 invalid;       /**< Set if this attribute had argument errors, */
  64         bool                 has_arguments; /**< True, if this attribute has arguments. */
  65         union {
  66                 size_t              value;
  67                 string_t            string;
  68                 symbol_t           *symbol;
  69                 long                argument;  /**< Single argument. */
  70                 argument_list_t    *arguments; /**< List of argument expressions. */
  71         } u;
  72 };
  73
  74 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  75 struct declaration_specifiers_t {
  76         source_position_t  source_position;
  77         storage_class_t    storage_class;
  78         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  79         bool               is_inline    : 1;
  80         bool               thread_local : 1;  /**< GCC __thread */
  81         bool               deprecated   : 1;
  82         decl_modifiers_t   modifiers;         /**< declaration modifiers */
  83         gnu_attribute_t   *gnu_attributes;    /**< list of GNU attributes */
  84         const char        *deprecated_string; /**< can be set if declaration was marked deprecated. */
  85         symbol_t          *get_property_sym;  /**< the name of the get property if set. */
  86         symbol_t          *put_property_sym;  /**< the name of the put property if set. */
  87         type_t            *type;
  88 };
  89
  90 /**
  91  * An environment for parsing initializers (and compound literals).
  92  */
  93 typedef struct parse_initializer_env_t {
  94         type_t     *type;   /**< the type of the initializer. In case of an
  95                                  array type with unspecified size this gets
  96                                  adjusted to the actual size. */
  97         entity_t   *entity; /**< the variable that is initialized if any */
  98         bool        must_be_constant;
  99 } parse_initializer_env_t;
 100
 101 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
 102
 103 /** The current token. */
 104 static token_t              token;
 105 /** The lookahead ring-buffer. */
 106 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
 107 /** Position of the next token in the lookahead buffer. */
 108 static size_t               lookahead_bufpos;
 109 static stack_entry_t       *environment_stack = NULL;
 110 static stack_entry_t       *label_stack       = NULL;
 111 static scope_t             *file_scope        = NULL;
 112 static scope_t             *current_scope     = NULL;
 113 /** Point to the current function declaration if inside a function. */
 114 static function_t          *current_function  = NULL;
 115 static entity_t            *current_init_decl = NULL;
 116 static switch_statement_t  *current_switch    = NULL;
 117 static statement_t         *current_loop      = NULL;
 118 static statement_t         *current_parent    = NULL;
 119 static ms_try_statement_t  *current_try       = NULL;
 120 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
 121 static goto_statement_t    *goto_first        = NULL;
 122 static goto_statement_t   **goto_anchor       = NULL;
 123 static label_statement_t   *label_first       = NULL;
 124 static label_statement_t  **label_anchor      = NULL;
 125 /** current translation unit. */
 126 static translation_unit_t  *unit              = NULL;
 127 /** true if we are in a type property context (evaluation only for type. */
 128 static bool                 in_type_prop      = false;
 129 /** true in we are in a __extension__ context. */
 130 static bool                 in_gcc_extension  = false;
 131 static struct obstack       temp_obst;
 132 static entity_t            *anonymous_entity;
 133 static declaration_t      **incomplete_arrays;
 134
 135
 136 #define PUSH_PARENT(stmt)                          \
 137         statement_t *const prev_parent = current_parent; \
 138         ((void)(current_parent = (stmt)))
 139 #define POP_PARENT ((void)(current_parent = prev_parent))
 140
 141 /** special symbol used for anonymous entities. */
 142 static const symbol_t *sym_anonymous = NULL;
 143
 144 /* symbols for Microsoft extended-decl-modifier */
 145 static const symbol_t *sym_align         = NULL;
 146 static const symbol_t *sym_allocate      = NULL;
 147 static const symbol_t *sym_dllimport     = NULL;
 148 static const symbol_t *sym_dllexport     = NULL;
 149 static const symbol_t *sym_naked         = NULL;
 150 static const symbol_t *sym_noinline      = NULL;
 151 static const symbol_t *sym_returns_twice = NULL;
 152 static const symbol_t *sym_noreturn      = NULL;
 153 static const symbol_t *sym_nothrow       = NULL;
 154 static const symbol_t *sym_novtable      = NULL;
 155 static const symbol_t *sym_property      = NULL;
 156 static const symbol_t *sym_get           = NULL;
 157 static const symbol_t *sym_put           = NULL;
 158 static const symbol_t *sym_selectany     = NULL;
 159 static const symbol_t *sym_thread        = NULL;
 160 static const symbol_t *sym_uuid          = NULL;
 161 static const symbol_t *sym_deprecated    = NULL;
 162 static const symbol_t *sym_restrict      = NULL;
 163 static const symbol_t *sym_noalias       = NULL;
 164
 165 /** The token anchor set */
 166 static unsigned char token_anchor_set[T_LAST_TOKEN];
 167
 168 /** The current source position. */
 169 #define HERE (&token.source_position)
 170
 171 /** true if we are in GCC mode. */
 172 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 173
 174 static statement_t *parse_compound_statement(bool inside_expression_statement);
 175 static statement_t *parse_statement(void);
 176
 177 static expression_t *parse_sub_expression(precedence_t);
 178 static expression_t *parse_expression(void);
 179 static type_t       *parse_typename(void);
 180 static void          parse_externals(void);
 181 static void          parse_external(void);
 182
 183 static void parse_compound_type_entries(compound_t *compound_declaration);
 184
 185 static void check_call_argument(type_t          *expected_type,
 186                                                                 call_argument_t *argument, unsigned pos);
 187
 188 typedef enum declarator_flags_t {
 189         DECL_FLAGS_NONE             = 0,
 190         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 191         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 192         DECL_IS_PARAMETER           = 1U << 2
 193 } declarator_flags_t;
 194
 195 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 196                                   declarator_flags_t flags);
 197
 198 static entity_t *record_entity(entity_t *entity, bool is_definition);
 199
 200 static void semantic_comparison(binary_expression_t *expression);
 201
 202 static void create_gnu_builtins(void);
 203 static void create_microsoft_intrinsics(void);
 204
 205 #define STORAGE_CLASSES       \
 206         STORAGE_CLASSES_NO_EXTERN \
 207         case T_extern:
 208
 209 #define STORAGE_CLASSES_NO_EXTERN \
 210         case T_typedef:         \
 211         case T_static:          \
 212         case T_auto:            \
 213         case T_register:        \
 214         case T___thread:
 215
 216 #define TYPE_QUALIFIERS     \
 217         case T_const:           \
 218         case T_restrict:        \
 219         case T_volatile:        \
 220         case T_inline:          \
 221         case T__forceinline:    \
 222         case T___attribute__:
 223
 224 #define COMPLEX_SPECIFIERS  \
 225         case T__Complex:
 226 #define IMAGINARY_SPECIFIERS \
 227         case T__Imaginary:
 228
 229 #define TYPE_SPECIFIERS       \
 230         case T__Bool:             \
 231         case T___builtin_va_list: \
 232         case T___typeof__:        \
 233         case T__declspec:         \
 234         case T_bool:              \
 235         case T_char:              \
 236         case T_double:            \
 237         case T_enum:              \
 238         case T_float:             \
 239         case T_int:               \
 240         case T_long:              \
 241         case T_short:             \
 242         case T_signed:            \
 243         case T_struct:            \
 244         case T_union:             \
 245         case T_unsigned:          \
 246         case T_void:              \
 247         case T_wchar_t:           \
 248         COMPLEX_SPECIFIERS        \
 249         IMAGINARY_SPECIFIERS
 250
 251 #define DECLARATION_START   \
 252         STORAGE_CLASSES         \
 253         TYPE_QUALIFIERS         \
 254         TYPE_SPECIFIERS
 255
 256 #define DECLARATION_START_NO_EXTERN \
 257         STORAGE_CLASSES_NO_EXTERN       \
 258         TYPE_QUALIFIERS                 \
 259         TYPE_SPECIFIERS
 260
 261 #define TYPENAME_START      \
 262         TYPE_QUALIFIERS         \
 263         TYPE_SPECIFIERS
 264
 265 #define EXPRESSION_START           \
 266         case '!':                        \
 267         case '&':                        \
 268         case '(':                        \
 269         case '*':                        \
 270         case '+':                        \
 271         case '-':                        \
 272         case '~':                        \
 273         case T_ANDAND:                   \
 274         case T_CHARACTER_CONSTANT:       \
 275         case T_FLOATINGPOINT:            \
 276         case T_INTEGER:                  \
 277         case T_MINUSMINUS:               \
 278         case T_PLUSPLUS:                 \
 279         case T_STRING_LITERAL:           \
 280         case T_WIDE_CHARACTER_CONSTANT:  \
 281         case T_WIDE_STRING_LITERAL:      \
 282         case T___FUNCDNAME__:            \
 283         case T___FUNCSIG__:              \
 284         case T___FUNCTION__:             \
 285         case T___PRETTY_FUNCTION__:      \
 286         case T___alignof__:              \
 287         case T___builtin_classify_type:  \
 288         case T___builtin_constant_p:     \
 289         case T___builtin_isgreater:      \
 290         case T___builtin_isgreaterequal: \
 291         case T___builtin_isless:         \
 292         case T___builtin_islessequal:    \
 293         case T___builtin_islessgreater:  \
 294         case T___builtin_isunordered:    \
 295         case T___builtin_offsetof:       \
 296         case T___builtin_va_arg:         \
 297         case T___builtin_va_start:       \
 298         case T___builtin_va_copy:        \
 299         case T___func__:                 \
 300         case T___noop:                   \
 301         case T__assume:                  \
 302         case T_delete:                   \
 303         case T_false:                    \
 304         case T_sizeof:                   \
 305         case T_throw:                    \
 306         case T_true:
 307
 308 /**
 309  * Allocate an AST node with given size and
 310  * initialize all fields with zero.
 311  */
 312 static void *allocate_ast_zero(size_t size)
 313 {
 314         void *res = allocate_ast(size);
 315         memset(res, 0, size);
 316         return res;
 317 }
 318
 319 /**
 320  * Returns the size of an entity node.
 321  *
 322  * @param kind  the entity kind
 323  */
 324 static size_t get_entity_struct_size(entity_kind_t kind)
 325 {
 326         static const size_t sizes[] = {
 327                 [ENTITY_VARIABLE]        = sizeof(variable_t),
 328                 [ENTITY_PARAMETER]       = sizeof(parameter_t),
 329                 [ENTITY_COMPOUND_MEMBER] = sizeof(compound_member_t),
 330                 [ENTITY_FUNCTION]        = sizeof(function_t),
 331                 [ENTITY_TYPEDEF]         = sizeof(typedef_t),
 332                 [ENTITY_STRUCT]          = sizeof(compound_t),
 333                 [ENTITY_UNION]           = sizeof(compound_t),
 334                 [ENTITY_ENUM]            = sizeof(enum_t),
 335                 [ENTITY_ENUM_VALUE]      = sizeof(enum_value_t),
 336                 [ENTITY_LABEL]           = sizeof(label_t),
 337                 [ENTITY_LOCAL_LABEL]     = sizeof(label_t),
 338                 [ENTITY_NAMESPACE]       = sizeof(namespace_t)
 339         };
 340         assert(kind < lengthof(sizes));
 341         assert(sizes[kind] != 0);
 342         return sizes[kind];
 343 }
 344
 345 /**
 346  * Allocate an entity of given kind and initialize all
 347  * fields with zero.
 348  *
 349  * @param kind   the kind of the entity to allocate
 350  */
 351 static entity_t *allocate_entity_zero(entity_kind_t kind)
 352 {
 353         size_t    size   = get_entity_struct_size(kind);
 354         entity_t *entity = allocate_ast_zero(size);
 355         entity->kind     = kind;
 356         return entity;
 357 }
 358
 359 /**
 360  * Returns the size of a statement node.
 361  *
 362  * @param kind  the statement kind
 363  */
 364 static size_t get_statement_struct_size(statement_kind_t kind)
 365 {
 366         static const size_t sizes[] = {
 367                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 368                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 369                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 370                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 371                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 372                 [STATEMENT_IF]          = sizeof(if_statement_t),
 373                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 374                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 375                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 376                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 377                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 378                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 379                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 380                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 381                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 382                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 383                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 384                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 385                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 386         };
 387         assert(kind < lengthof(sizes));
 388         assert(sizes[kind] != 0);
 389         return sizes[kind];
 390 }
 391
 392 /**
 393  * Returns the size of an expression node.
 394  *
 395  * @param kind  the expression kind
 396  */
 397 static size_t get_expression_struct_size(expression_kind_t kind)
 398 {
 399         static const size_t sizes[] = {
 400                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 401                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 402                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 403                 [EXPR_CONST]                      = sizeof(const_expression_t),
 404                 [EXPR_CHARACTER_CONSTANT]         = sizeof(const_expression_t),
 405                 [EXPR_WIDE_CHARACTER_CONSTANT]    = sizeof(const_expression_t),
 406                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 407                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(wide_string_literal_expression_t),
 408                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 409                 [EXPR_CALL]                       = sizeof(call_expression_t),
 410                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 411                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 412                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 413                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 414                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 415                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 416                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 417                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 418                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 419                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 420                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 421                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 422                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 423                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 424                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 425                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 426                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 427         };
 428         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 429                 return sizes[EXPR_UNARY_FIRST];
 430         }
 431         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 432                 return sizes[EXPR_BINARY_FIRST];
 433         }
 434         assert(kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate a statement node of given kind and initialize all
 441  * fields with zero. Sets its source position to the position
 442  * of the current token.
 443  */
 444 static statement_t *allocate_statement_zero(statement_kind_t kind)
 445 {
 446         size_t       size = get_statement_struct_size(kind);
 447         statement_t *res  = allocate_ast_zero(size);
 448
 449         res->base.kind            = kind;
 450         res->base.parent          = current_parent;
 451         res->base.source_position = token.source_position;
 452         return res;
 453 }
 454
 455 /**
 456  * Allocate an expression node of given kind and initialize all
 457  * fields with zero.
 458  *
 459  * @param kind  the kind of the expression to allocate
 460  */
 461 static expression_t *allocate_expression_zero(expression_kind_t kind)
 462 {
 463         size_t        size = get_expression_struct_size(kind);
 464         expression_t *res  = allocate_ast_zero(size);
 465
 466         res->base.kind            = kind;
 467         res->base.type            = type_error_type;
 468         res->base.source_position = token.source_position;
 469         return res;
 470 }
 471
 472 /**
 473  * Creates a new invalid expression at the source position
 474  * of the current token.
 475  */
 476 static expression_t *create_invalid_expression(void)
 477 {
 478         return allocate_expression_zero(EXPR_INVALID);
 479 }
 480
 481 /**
 482  * Creates a new invalid statement.
 483  */
 484 static statement_t *create_invalid_statement(void)
 485 {
 486         return allocate_statement_zero(STATEMENT_INVALID);
 487 }
 488
 489 /**
 490  * Allocate a new empty statement.
 491  */
 492 static statement_t *create_empty_statement(void)
 493 {
 494         return allocate_statement_zero(STATEMENT_EMPTY);
 495 }
 496
 497 /**
 498  * Returns the size of a type node.
 499  *
 500  * @param kind  the type kind
 501  */
 502 static size_t get_type_struct_size(type_kind_t kind)
 503 {
 504         static const size_t sizes[] = {
 505                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 506                 [TYPE_COMPLEX]         = sizeof(complex_type_t),
 507                 [TYPE_IMAGINARY]       = sizeof(imaginary_type_t),
 508                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 509                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 510                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 511                 [TYPE_ENUM]            = sizeof(enum_type_t),
 512                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 513                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 514                 [TYPE_ARRAY]           = sizeof(array_type_t),
 515                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 516                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 517                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 518         };
 519         assert(lengthof(sizes) == (int)TYPE_TYPEOF + 1);
 520         assert(kind <= TYPE_TYPEOF);
 521         assert(sizes[kind] != 0);
 522         return sizes[kind];
 523 }
 524
 525 /**
 526  * Allocate a type node of given kind and initialize all
 527  * fields with zero.
 528  *
 529  * @param kind             type kind to allocate
 530  */
 531 static type_t *allocate_type_zero(type_kind_t kind)
 532 {
 533         size_t  size = get_type_struct_size(kind);
 534         type_t *res  = obstack_alloc(type_obst, size);
 535         memset(res, 0, size);
 536         res->base.kind = kind;
 537
 538         return res;
 539 }
 540
 541 static function_parameter_t *allocate_parameter(type_t *const type)
 542 {
 543         function_parameter_t *const param = obstack_alloc(type_obst, sizeof(*param));
 544         memset(param, 0, sizeof(*param));
 545         param->type = type;
 546         return param;
 547 }
 548
 549 /**
 550  * Returns the size of an initializer node.
 551  *
 552  * @param kind  the initializer kind
 553  */
 554 static size_t get_initializer_size(initializer_kind_t kind)
 555 {
 556         static const size_t sizes[] = {
 557                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 558                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 559                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 560                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 561                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 562         };
 563         assert(kind < lengthof(sizes));
 564         assert(sizes[kind] != 0);
 565         return sizes[kind];
 566 }
 567
 568 /**
 569  * Allocate an initializer node of given kind and initialize all
 570  * fields with zero.
 571  */
 572 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 573 {
 574         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 575         result->kind          = kind;
 576
 577         return result;
 578 }
 579
 580 /**
 581  * Returns the index of the top element of the environment stack.
 582  */
 583 static size_t environment_top(void)
 584 {
 585         return ARR_LEN(environment_stack);
 586 }
 587
 588 /**
 589  * Returns the index of the top element of the global label stack.
 590  */
 591 static size_t label_top(void)
 592 {
 593         return ARR_LEN(label_stack);
 594 }
 595
 596 /**
 597  * Return the next token.
 598  */
 599 static inline void next_token(void)
 600 {
 601         token                              = lookahead_buffer[lookahead_bufpos];
 602         lookahead_buffer[lookahead_bufpos] = lexer_token;
 603         lexer_next_token();
 604
 605         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 606
 607 #ifdef PRINT_TOKENS
 608         print_token(stderr, &token);
 609         fprintf(stderr, "\n");
 610 #endif
 611 }
 612
 613 /**
 614  * Return the next token with a given lookahead.
 615  */
 616 static inline const token_t *look_ahead(size_t num)
 617 {
 618         assert(0 < num && num <= MAX_LOOKAHEAD);
 619         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 620         return &lookahead_buffer[pos];
 621 }
 622
 623 /**
 624  * Adds a token type to the token type anchor set (a multi-set).
 625  */
 626 static void add_anchor_token(int token_type)
 627 {
 628         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 629         ++token_anchor_set[token_type];
 630 }
 631
 632 /**
 633  * Set the number of tokens types of the given type
 634  * to zero and return the old count.
 635  */
 636 static int save_and_reset_anchor_state(int token_type)
 637 {
 638         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 639         int count = token_anchor_set[token_type];
 640         token_anchor_set[token_type] = 0;
 641         return count;
 642 }
 643
 644 /**
 645  * Restore the number of token types to the given count.
 646  */
 647 static void restore_anchor_state(int token_type, int count)
 648 {
 649         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 650         token_anchor_set[token_type] = count;
 651 }
 652
 653 /**
 654  * Remove a token type from the token type anchor set (a multi-set).
 655  */
 656 static void rem_anchor_token(int token_type)
 657 {
 658         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 659         assert(token_anchor_set[token_type] != 0);
 660         --token_anchor_set[token_type];
 661 }
 662
 663 /**
 664  * Return true if the token type of the current token is
 665  * in the anchor set.
 666  */
 667 static bool at_anchor(void)
 668 {
 669         if (token.type < 0)
 670                 return false;
 671         return token_anchor_set[token.type];
 672 }
 673
 674 /**
 675  * Eat tokens until a matching token type is found.
 676  */
 677 static void eat_until_matching_token(int type)
 678 {
 679         int end_token;
 680         switch (type) {
 681                 case '(': end_token = ')';  break;
 682                 case '{': end_token = '}';  break;
 683                 case '[': end_token = ']';  break;
 684                 default:  end_token = type; break;
 685         }
 686
 687         unsigned parenthesis_count = 0;
 688         unsigned brace_count       = 0;
 689         unsigned bracket_count     = 0;
 690         while (token.type        != end_token ||
 691                parenthesis_count != 0         ||
 692                brace_count       != 0         ||
 693                bracket_count     != 0) {
 694                 switch (token.type) {
 695                 case T_EOF: return;
 696                 case '(': ++parenthesis_count; break;
 697                 case '{': ++brace_count;       break;
 698                 case '[': ++bracket_count;     break;
 699
 700                 case ')':
 701                         if (parenthesis_count > 0)
 702                                 --parenthesis_count;
 703                         goto check_stop;
 704
 705                 case '}':
 706                         if (brace_count > 0)
 707                                 --brace_count;
 708                         goto check_stop;
 709
 710                 case ']':
 711                         if (bracket_count > 0)
 712                                 --bracket_count;
 713 check_stop:
 714                         if (token.type        == end_token &&
 715                             parenthesis_count == 0         &&
 716                             brace_count       == 0         &&
 717                             bracket_count     == 0)
 718                                 return;
 719                         break;
 720
 721                 default:
 722                         break;
 723                 }
 724                 next_token();
 725         }
 726 }
 727
 728 /**
 729  * Eat input tokens until an anchor is found.
 730  */
 731 static void eat_until_anchor(void)
 732 {
 733         while (token_anchor_set[token.type] == 0) {
 734                 if (token.type == '(' || token.type == '{' || token.type == '[')
 735                         eat_until_matching_token(token.type);
 736                 next_token();
 737         }
 738 }
 739
 740 /**
 741  * Eat a whole block from input tokens.
 742  */
 743 static void eat_block(void)
 744 {
 745         eat_until_matching_token('{');
 746         if (token.type == '}')
 747                 next_token();
 748 }
 749
 750 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 751
 752 /**
 753  * Report a parse error because an expected token was not found.
 754  */
 755 static
 756 #if defined __GNUC__ && __GNUC__ >= 4
 757 __attribute__((sentinel))
 758 #endif
 759 void parse_error_expected(const char *message, ...)
 760 {
 761         if (message != NULL) {
 762                 errorf(HERE, "%s", message);
 763         }
 764         va_list ap;
 765         va_start(ap, message);
 766         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 767         va_end(ap);
 768 }
 769
 770 /**
 771  * Report an incompatible type.
 772  */
 773 static void type_error_incompatible(const char *msg,
 774                 const source_position_t *source_position, type_t *type1, type_t *type2)
 775 {
 776         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 777                msg, type1, type2);
 778 }
 779
 780 /**
 781  * Expect the current token is the expected token.
 782  * If not, generate an error, eat the current statement,
 783  * and goto the end_error label.
 784  */
 785 #define expect(expected, error_label)                     \
 786         do {                                                  \
 787                 if (UNLIKELY(token.type != (expected))) {         \
 788                         parse_error_expected(NULL, (expected), NULL); \
 789                         add_anchor_token(expected);                   \
 790                         eat_until_anchor();                           \
 791                         if (token.type == expected)                   \
 792                                 next_token();                             \
 793                         rem_anchor_token(expected);                   \
 794                         goto error_label;                             \
 795                 }                                                 \
 796                 next_token();                                     \
 797         } while (0)
 798
 799 /**
 800  * Push a given scope on the scope stack and make it the
 801  * current scope
 802  */
 803 static scope_t *scope_push(scope_t *new_scope)
 804 {
 805         if (current_scope != NULL) {
 806                 new_scope->depth = current_scope->depth + 1;
 807         }
 808
 809         scope_t *old_scope = current_scope;
 810         current_scope      = new_scope;
 811         return old_scope;
 812 }
 813
 814 /**
 815  * Pop the current scope from the scope stack.
 816  */
 817 static void scope_pop(scope_t *old_scope)
 818 {
 819         current_scope = old_scope;
 820 }
 821
 822 /**
 823  * Search an entity by its symbol in a given namespace.
 824  */
 825 static entity_t *get_entity(const symbol_t *const symbol,
 826                             namespace_tag_t namespc)
 827 {
 828         entity_t *entity = symbol->entity;
 829         for (; entity != NULL; entity = entity->base.symbol_next) {
 830                 if (entity->base.namespc == namespc)
 831                         return entity;
 832         }
 833
 834         return NULL;
 835 }
 836
 837 /**
 838  * pushs an entity on the environment stack and links the corresponding symbol
 839  * it.
 840  */
 841 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 842 {
 843         symbol_t           *symbol  = entity->base.symbol;
 844         entity_namespace_t  namespc = entity->base.namespc;
 845         assert(namespc != NAMESPACE_INVALID);
 846
 847         /* replace/add entity into entity list of the symbol */
 848         entity_t **anchor;
 849         entity_t  *iter;
 850         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 851                 iter = *anchor;
 852                 if (iter == NULL)
 853                         break;
 854
 855                 /* replace an entry? */
 856                 if (iter->base.namespc == namespc) {
 857                         entity->base.symbol_next = iter->base.symbol_next;
 858                         break;
 859                 }
 860         }
 861         *anchor = entity;
 862
 863         /* remember old declaration */
 864         stack_entry_t entry;
 865         entry.symbol     = symbol;
 866         entry.old_entity = iter;
 867         entry.namespc    = namespc;
 868         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 869 }
 870
 871 /**
 872  * Push an entity on the environment stack.
 873  */
 874 static void environment_push(entity_t *entity)
 875 {
 876         assert(entity->base.source_position.input_name != NULL);
 877         assert(entity->base.parent_scope != NULL);
 878         stack_push(&environment_stack, entity);
 879 }
 880
 881 /**
 882  * Push a declaration on the global label stack.
 883  *
 884  * @param declaration  the declaration
 885  */
 886 static void label_push(entity_t *label)
 887 {
 888         /* we abuse the parameters scope as parent for the labels */
 889         label->base.parent_scope = &current_function->parameters;
 890         stack_push(&label_stack, label);
 891 }
 892
 893 /**
 894  * pops symbols from the environment stack until @p new_top is the top element
 895  */
 896 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 897 {
 898         stack_entry_t *stack = *stack_ptr;
 899         size_t         top   = ARR_LEN(stack);
 900         size_t         i;
 901
 902         assert(new_top <= top);
 903         if (new_top == top)
 904                 return;
 905
 906         for (i = top; i > new_top; --i) {
 907                 stack_entry_t *entry = &stack[i - 1];
 908
 909                 entity_t           *old_entity = entry->old_entity;
 910                 symbol_t           *symbol     = entry->symbol;
 911                 entity_namespace_t  namespc    = entry->namespc;
 912
 913                 /* replace with old_entity/remove */
 914                 entity_t **anchor;
 915                 entity_t  *iter;
 916                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 917                         iter = *anchor;
 918                         assert(iter != NULL);
 919                         /* replace an entry? */
 920                         if (iter->base.namespc == namespc)
 921                                 break;
 922                 }
 923
 924                 /* restore definition from outer scopes (if there was one) */
 925                 if (old_entity != NULL) {
 926                         old_entity->base.symbol_next = iter->base.symbol_next;
 927                         *anchor                      = old_entity;
 928                 } else {
 929                         /* remove entry from list */
 930                         *anchor = iter->base.symbol_next;
 931                 }
 932         }
 933
 934         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 935 }
 936
 937 /**
 938  * Pop all entries from the environment stack until the new_top
 939  * is reached.
 940  *
 941  * @param new_top  the new stack top
 942  */
 943 static void environment_pop_to(size_t new_top)
 944 {
 945         stack_pop_to(&environment_stack, new_top);
 946 }
 947
 948 /**
 949  * Pop all entries from the global label stack until the new_top
 950  * is reached.
 951  *
 952  * @param new_top  the new stack top
 953  */
 954 static void label_pop_to(size_t new_top)
 955 {
 956         stack_pop_to(&label_stack, new_top);
 957 }
 958
 959 static int get_akind_rank(atomic_type_kind_t akind)
 960 {
 961         return (int) akind;
 962 }
 963
 964 /**
 965  * Return the type rank for an atomic type.
 966  */
 967 static int get_rank(const type_t *type)
 968 {
 969         assert(!is_typeref(type));
 970         if (type->kind == TYPE_ENUM)
 971                 return get_akind_rank(type->enumt.akind);
 972
 973         assert(type->kind == TYPE_ATOMIC);
 974         return get_akind_rank(type->atomic.akind);
 975 }
 976
 977 /**
 978  * Do integer promotion for a given type.
 979  *
 980  * @param type  the type to promote
 981  * @return the promoted type
 982  */
 983 static type_t *promote_integer(type_t *type)
 984 {
 985         if (type->kind == TYPE_BITFIELD)
 986                 type = type->bitfield.base_type;
 987
 988         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 989                 type = type_int;
 990
 991         return type;
 992 }
 993
 994 /**
 995  * Create a cast expression.
 996  *
 997  * @param expression  the expression to cast
 998  * @param dest_type   the destination type
 999  */
1000 static expression_t *create_cast_expression(expression_t *expression,
1001                                             type_t *dest_type)
1002 {
1003         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
1004
1005         cast->unary.value = expression;
1006         cast->base.type   = dest_type;
1007
1008         return cast;
1009 }
1010
1011 /**
1012  * Check if a given expression represents a null pointer constant.
1013  *
1014  * @param expression  the expression to check
1015  */
1016 static bool is_null_pointer_constant(const expression_t *expression)
1017 {
1018         /* skip void* cast */
1019         if (expression->kind == EXPR_UNARY_CAST ||
1020                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
1021                 type_t *const type = skip_typeref(expression->base.type);
1022                 if (types_compatible(type, type_void_ptr))
1023                         expression = expression->unary.value;
1024         }
1025
1026         type_t *const type = skip_typeref(expression->base.type);
1027         return
1028                 is_type_integer(type)              &&
1029                 is_constant_expression(expression) &&
1030                 fold_constant(expression) == 0;
1031 }
1032
1033 /**
1034  * Create an implicit cast expression.
1035  *
1036  * @param expression  the expression to cast
1037  * @param dest_type   the destination type
1038  */
1039 static expression_t *create_implicit_cast(expression_t *expression,
1040                                           type_t *dest_type)
1041 {
1042         type_t *const source_type = expression->base.type;
1043
1044         if (source_type == dest_type)
1045                 return expression;
1046
1047         return create_cast_expression(expression, dest_type);
1048 }
1049
1050 typedef enum assign_error_t {
1051         ASSIGN_SUCCESS,
1052         ASSIGN_ERROR_INCOMPATIBLE,
1053         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
1054         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
1055         ASSIGN_WARNING_POINTER_FROM_INT,
1056         ASSIGN_WARNING_INT_FROM_POINTER
1057 } assign_error_t;
1058
1059 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
1060                                 const expression_t *const right,
1061                                 const char *context,
1062                                 const source_position_t *source_position)
1063 {
1064         type_t *const orig_type_right = right->base.type;
1065         type_t *const type_left       = skip_typeref(orig_type_left);
1066         type_t *const type_right      = skip_typeref(orig_type_right);
1067
1068         switch (error) {
1069         case ASSIGN_SUCCESS:
1070                 return;
1071         case ASSIGN_ERROR_INCOMPATIBLE:
1072                 errorf(source_position,
1073                        "destination type '%T' in %s is incompatible with type '%T'",
1074                        orig_type_left, context, orig_type_right);
1075                 return;
1076
1077         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
1078                 if (warning.other) {
1079                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
1080                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
1081
1082                         /* the left type has all qualifiers from the right type */
1083                         unsigned missing_qualifiers
1084                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1085                         warningf(source_position,
1086                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
1087                                         orig_type_left, context, orig_type_right, missing_qualifiers);
1088                 }
1089                 return;
1090         }
1091
1092         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
1093                 if (warning.other) {
1094                         warningf(source_position,
1095                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
1096                                         orig_type_left, context, right, orig_type_right);
1097                 }
1098                 return;
1099
1100         case ASSIGN_WARNING_POINTER_FROM_INT:
1101                 if (warning.other) {
1102                         warningf(source_position,
1103                                         "%s makes pointer '%T' from integer '%T' without a cast",
1104                                         context, orig_type_left, orig_type_right);
1105                 }
1106                 return;
1107
1108         case ASSIGN_WARNING_INT_FROM_POINTER:
1109                 if (warning.other) {
1110                         warningf(source_position,
1111                                         "%s makes integer '%T' from pointer '%T' without a cast",
1112                                         context, orig_type_left, orig_type_right);
1113                 }
1114                 return;
1115
1116         default:
1117                 panic("invalid error value");
1118         }
1119 }
1120
1121 /** Implements the rules from §6.5.16.1 */
1122 static assign_error_t semantic_assign(type_t *orig_type_left,
1123                                       const expression_t *const right)
1124 {
1125         type_t *const orig_type_right = right->base.type;
1126         type_t *const type_left       = skip_typeref(orig_type_left);
1127         type_t *const type_right      = skip_typeref(orig_type_right);
1128
1129         if (is_type_pointer(type_left)) {
1130                 if (is_null_pointer_constant(right)) {
1131                         return ASSIGN_SUCCESS;
1132                 } else if (is_type_pointer(type_right)) {
1133                         type_t *points_to_left
1134                                 = skip_typeref(type_left->pointer.points_to);
1135                         type_t *points_to_right
1136                                 = skip_typeref(type_right->pointer.points_to);
1137                         assign_error_t res = ASSIGN_SUCCESS;
1138
1139                         /* the left type has all qualifiers from the right type */
1140                         unsigned missing_qualifiers
1141                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1142                         if (missing_qualifiers != 0) {
1143                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1144                         }
1145
1146                         points_to_left  = get_unqualified_type(points_to_left);
1147                         points_to_right = get_unqualified_type(points_to_right);
1148
1149                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1150                                 return res;
1151
1152                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1153                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1154                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1155                         }
1156
1157                         if (!types_compatible(points_to_left, points_to_right)) {
1158                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1159                         }
1160
1161                         return res;
1162                 } else if (is_type_integer(type_right)) {
1163                         return ASSIGN_WARNING_POINTER_FROM_INT;
1164                 }
1165         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1166             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1167                 && is_type_pointer(type_right))) {
1168                 return ASSIGN_SUCCESS;
1169         } else if ((is_type_compound(type_left)  && is_type_compound(type_right))
1170                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
1171                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1172                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1173                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1174                         return ASSIGN_SUCCESS;
1175                 }
1176         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1177                 return ASSIGN_WARNING_INT_FROM_POINTER;
1178         }
1179
1180         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1181                 return ASSIGN_SUCCESS;
1182
1183         return ASSIGN_ERROR_INCOMPATIBLE;
1184 }
1185
1186 static expression_t *parse_constant_expression(void)
1187 {
1188         expression_t *result = parse_sub_expression(PREC_CONDITIONAL);
1189
1190         if (!is_constant_expression(result)) {
1191                 errorf(&result->base.source_position,
1192                        "expression '%E' is not constant", result);
1193         }
1194
1195         return result;
1196 }
1197
1198 static expression_t *parse_assignment_expression(void)
1199 {
1200         return parse_sub_expression(PREC_ASSIGNMENT);
1201 }
1202
1203 static string_t parse_string_literals(void)
1204 {
1205         assert(token.type == T_STRING_LITERAL);
1206         string_t result = token.v.string;
1207
1208         next_token();
1209
1210         while (token.type == T_STRING_LITERAL) {
1211                 result = concat_strings(&result, &token.v.string);
1212                 next_token();
1213         }
1214
1215         return result;
1216 }
1217
1218 static const char *const gnu_attribute_names[GNU_AK_LAST] = {
1219         [GNU_AK_CONST]                  = "const",
1220         [GNU_AK_VOLATILE]               = "volatile",
1221         [GNU_AK_CDECL]                  = "cdecl",
1222         [GNU_AK_STDCALL]                = "stdcall",
1223         [GNU_AK_FASTCALL]               = "fastcall",
1224         [GNU_AK_DEPRECATED]             = "deprecated",
1225         [GNU_AK_NOINLINE]               = "noinline",
1226         [GNU_AK_RETURNS_TWICE]          = "returns_twice",
1227         [GNU_AK_NORETURN]               = "noreturn",
1228         [GNU_AK_NAKED]                  = "naked",
1229         [GNU_AK_PURE]                   = "pure",
1230         [GNU_AK_ALWAYS_INLINE]          = "always_inline",
1231         [GNU_AK_MALLOC]                 = "malloc",
1232         [GNU_AK_WEAK]                   = "weak",
1233         [GNU_AK_CONSTRUCTOR]            = "constructor",
1234         [GNU_AK_DESTRUCTOR]             = "destructor",
1235         [GNU_AK_NOTHROW]                = "nothrow",
1236         [GNU_AK_TRANSPARENT_UNION]      = "transparent_union",
1237         [GNU_AK_COMMON]                 = "common",
1238         [GNU_AK_NOCOMMON]               = "nocommon",
1239         [GNU_AK_PACKED]                 = "packed",
1240         [GNU_AK_SHARED]                 = "shared",
1241         [GNU_AK_NOTSHARED]              = "notshared",
1242         [GNU_AK_USED]                   = "used",
1243         [GNU_AK_UNUSED]                 = "unused",
1244         [GNU_AK_NO_INSTRUMENT_FUNCTION] = "no_instrument_function",
1245         [GNU_AK_WARN_UNUSED_RESULT]     = "warn_unused_result",
1246         [GNU_AK_LONGCALL]               = "longcall",
1247         [GNU_AK_SHORTCALL]              = "shortcall",
1248         [GNU_AK_LONG_CALL]              = "long_call",
1249         [GNU_AK_SHORT_CALL]             = "short_call",
1250         [GNU_AK_FUNCTION_VECTOR]        = "function_vector",
1251         [GNU_AK_INTERRUPT]              = "interrupt",
1252         [GNU_AK_INTERRUPT_HANDLER]      = "interrupt_handler",
1253         [GNU_AK_NMI_HANDLER]            = "nmi_handler",
1254         [GNU_AK_NESTING]                = "nesting",
1255         [GNU_AK_NEAR]                   = "near",
1256         [GNU_AK_FAR]                    = "far",
1257         [GNU_AK_SIGNAL]                 = "signal",
1258         [GNU_AK_EIGTHBIT_DATA]          = "eightbit_data",
1259         [GNU_AK_TINY_DATA]              = "tiny_data",
1260         [GNU_AK_SAVEALL]                = "saveall",
1261         [GNU_AK_FLATTEN]                = "flatten",
1262         [GNU_AK_SSEREGPARM]             = "sseregparm",
1263         [GNU_AK_EXTERNALLY_VISIBLE]     = "externally_visible",
1264         [GNU_AK_RETURN_TWICE]           = "return_twice",
1265         [GNU_AK_MAY_ALIAS]              = "may_alias",
1266         [GNU_AK_MS_STRUCT]              = "ms_struct",
1267         [GNU_AK_GCC_STRUCT]             = "gcc_struct",
1268         [GNU_AK_DLLIMPORT]              = "dllimport",
1269         [GNU_AK_DLLEXPORT]              = "dllexport",
1270         [GNU_AK_ALIGNED]                = "aligned",
1271         [GNU_AK_ALIAS]                  = "alias",
1272         [GNU_AK_SECTION]                = "section",
1273         [GNU_AK_FORMAT]                 = "format",
1274         [GNU_AK_FORMAT_ARG]             = "format_arg",
1275         [GNU_AK_WEAKREF]                = "weakref",
1276         [GNU_AK_NONNULL]                = "nonnull",
1277         [GNU_AK_TLS_MODEL]              = "tls_model",
1278         [GNU_AK_VISIBILITY]             = "visibility",
1279         [GNU_AK_REGPARM]                = "regparm",
1280         [GNU_AK_MODE]                   = "mode",
1281         [GNU_AK_MODEL]                  = "model",
1282         [GNU_AK_TRAP_EXIT]              = "trap_exit",
1283         [GNU_AK_SP_SWITCH]              = "sp_switch",
1284         [GNU_AK_SENTINEL]               = "sentinel"
1285 };
1286
1287 /**
1288  * compare two string, ignoring double underscores on the second.
1289  */
1290 static int strcmp_underscore(const char *s1, const char *s2)
1291 {
1292         if (s2[0] == '_' && s2[1] == '_') {
1293                 size_t len2 = strlen(s2);
1294                 size_t len1 = strlen(s1);
1295                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1296                         return strncmp(s1, s2+2, len2-4);
1297                 }
1298         }
1299
1300         return strcmp(s1, s2);
1301 }
1302
1303 /**
1304  * Allocate a new gnu temporal attribute of given kind.
1305  */
1306 static gnu_attribute_t *allocate_gnu_attribute(gnu_attribute_kind_t kind)
1307 {
1308         gnu_attribute_t *attribute = obstack_alloc(&temp_obst, sizeof(*attribute));
1309         attribute->kind            = kind;
1310         attribute->next            = NULL;
1311         attribute->invalid         = false;
1312         attribute->has_arguments   = false;
1313
1314         return attribute;
1315 }
1316
1317 /**
1318  * Parse one constant expression argument of the given attribute.
1319  */
1320 static void parse_gnu_attribute_const_arg(gnu_attribute_t *attribute)
1321 {
1322         expression_t *expression;
1323         add_anchor_token(')');
1324         expression = parse_constant_expression();
1325         rem_anchor_token(')');
1326         expect(')', end_error);
1327         attribute->u.argument = fold_constant(expression);
1328         return;
1329 end_error:
1330         attribute->invalid = true;
1331 }
1332
1333 /**
1334  * Parse a list of constant expressions arguments of the given attribute.
1335  */
1336 static void parse_gnu_attribute_const_arg_list(gnu_attribute_t *attribute)
1337 {
1338         argument_list_t **list = &attribute->u.arguments;
1339         argument_list_t  *entry;
1340         expression_t     *expression;
1341         add_anchor_token(')');
1342         add_anchor_token(',');
1343         while (true) {
1344                 expression = parse_constant_expression();
1345                 entry = obstack_alloc(&temp_obst, sizeof(entry));
1346                 entry->argument = fold_constant(expression);
1347                 entry->next     = NULL;
1348                 *list = entry;
1349                 list = &entry->next;
1350                 if (token.type != ',')
1351                         break;
1352                 next_token();
1353         }
1354         rem_anchor_token(',');
1355         rem_anchor_token(')');
1356         expect(')', end_error);
1357         return;
1358 end_error:
1359         attribute->invalid = true;
1360 }
1361
1362 /**
1363  * Parse one string literal argument of the given attribute.
1364  */
1365 static void parse_gnu_attribute_string_arg(gnu_attribute_t *attribute,
1366                                            string_t *string)
1367 {
1368         add_anchor_token('(');
1369         if (token.type != T_STRING_LITERAL) {
1370                 parse_error_expected("while parsing attribute directive",
1371                                      T_STRING_LITERAL, NULL);
1372                 goto end_error;
1373         }
1374         *string = parse_string_literals();
1375         rem_anchor_token('(');
1376         expect(')', end_error);
1377         return;
1378 end_error:
1379         attribute->invalid = true;
1380 }
1381
1382 /**
1383  * Parse one tls model of the given attribute.
1384  */
1385 static void parse_gnu_attribute_tls_model_arg(gnu_attribute_t *attribute)
1386 {
1387         static const char *const tls_models[] = {
1388                 "global-dynamic",
1389                 "local-dynamic",
1390                 "initial-exec",
1391                 "local-exec"
1392         };
1393         string_t string = { NULL, 0 };
1394         parse_gnu_attribute_string_arg(attribute, &string);
1395         if (string.begin != NULL) {
1396                 for (size_t i = 0; i < 4; ++i) {
1397                         if (strcmp(tls_models[i], string.begin) == 0) {
1398                                 attribute->u.value = i;
1399                                 return;
1400                         }
1401                 }
1402                 errorf(HERE, "'%s' is an unrecognized tls model", string.begin);
1403         }
1404         attribute->invalid = true;
1405 }
1406
1407 /**
1408  * Parse one tls model of the given attribute.
1409  */
1410 static void parse_gnu_attribute_visibility_arg(gnu_attribute_t *attribute)
1411 {
1412         static const char *const visibilities[] = {
1413                 "default",
1414                 "protected",
1415                 "hidden",
1416                 "internal"
1417         };
1418         string_t string = { NULL, 0 };
1419         parse_gnu_attribute_string_arg(attribute, &string);
1420         if (string.begin != NULL) {
1421                 for (size_t i = 0; i < 4; ++i) {
1422                         if (strcmp(visibilities[i], string.begin) == 0) {
1423                                 attribute->u.value = i;
1424                                 return;
1425                         }
1426                 }
1427                 errorf(HERE, "'%s' is an unrecognized visibility", string.begin);
1428         }
1429         attribute->invalid = true;
1430 }
1431
1432 /**
1433  * Parse one (code) model of the given attribute.
1434  */
1435 static void parse_gnu_attribute_model_arg(gnu_attribute_t *attribute)
1436 {
1437         static const char *const visibilities[] = {
1438                 "small",
1439                 "medium",
1440                 "large"
1441         };
1442         string_t string = { NULL, 0 };
1443         parse_gnu_attribute_string_arg(attribute, &string);
1444         if (string.begin != NULL) {
1445                 for (int i = 0; i < 3; ++i) {
1446                         if (strcmp(visibilities[i], string.begin) == 0) {
1447                                 attribute->u.value = i;
1448                                 return;
1449                         }
1450                 }
1451                 errorf(HERE, "'%s' is an unrecognized model", string.begin);
1452         }
1453         attribute->invalid = true;
1454 }
1455
1456 /**
1457  * Parse one mode of the given attribute.
1458  */
1459 static void parse_gnu_attribute_mode_arg(gnu_attribute_t *attribute)
1460 {
1461         add_anchor_token(')');
1462
1463         if (token.type != T_IDENTIFIER) {
1464                 expect(T_IDENTIFIER, end_error);
1465         }
1466
1467         attribute->u.symbol = token.v.symbol;
1468         next_token();
1469
1470         rem_anchor_token(')');
1471         expect(')', end_error);
1472         return;
1473 end_error:
1474         attribute->invalid = true;
1475 }
1476
1477 /**
1478  * Parse one interrupt argument of the given attribute.
1479  */
1480 static void parse_gnu_attribute_interrupt_arg(gnu_attribute_t *attribute)
1481 {
1482         static const char *const interrupts[] = {
1483                 "IRQ",
1484                 "FIQ",
1485                 "SWI",
1486                 "ABORT",
1487                 "UNDEF"
1488         };
1489         string_t string = { NULL, 0 };
1490         parse_gnu_attribute_string_arg(attribute, &string);
1491         if (string.begin != NULL) {
1492                 for (size_t i = 0; i < 5; ++i) {
1493                         if (strcmp(interrupts[i], string.begin) == 0) {
1494                                 attribute->u.value = i;
1495                                 return;
1496                         }
1497                 }
1498                 errorf(HERE, "'%s' is not an interrupt", string.begin);
1499         }
1500         attribute->invalid = true;
1501 }
1502
1503 /**
1504  * Parse ( identifier, const expression, const expression )
1505  */
1506 static void parse_gnu_attribute_format_args(gnu_attribute_t *attribute)
1507 {
1508         static const char *const format_names[] = {
1509                 "printf",
1510                 "scanf",
1511                 "strftime",
1512                 "strfmon"
1513         };
1514         int i;
1515
1516         if (token.type != T_IDENTIFIER) {
1517                 parse_error_expected("while parsing format attribute directive", T_IDENTIFIER, NULL);
1518                 goto end_error;
1519         }
1520         const char *name = token.v.symbol->string;
1521         for (i = 0; i < 4; ++i) {
1522                 if (strcmp_underscore(format_names[i], name) == 0)
1523                         break;
1524         }
1525         if (i >= 4) {
1526                 if (warning.attribute)
1527                         warningf(HERE, "'%s' is an unrecognized format function type", name);
1528         }
1529         next_token();
1530
1531         expect(',', end_error);
1532         add_anchor_token(')');
1533         add_anchor_token(',');
1534         parse_constant_expression();
1535         rem_anchor_token(',');
1536         rem_anchor_token(')');
1537
1538         expect(',', end_error);
1539         add_anchor_token(')');
1540         parse_constant_expression();
1541         rem_anchor_token(')');
1542         expect(')', end_error);
1543         return;
1544 end_error:
1545         attribute->u.value = true;
1546 }
1547
1548 /**
1549  * Check that a given GNU attribute has no arguments.
1550  */
1551 static void check_no_argument(gnu_attribute_t *attribute, const char *name)
1552 {
1553         if (!attribute->has_arguments)
1554                 return;
1555
1556         /* should have no arguments */
1557         errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1558         eat_until_matching_token('(');
1559         /* we have already consumed '(', so we stop before ')', eat it */
1560         next_token();
1561         attribute->invalid = true;
1562 }
1563
1564 /**
1565  * Parse one GNU attribute.
1566  *
1567  * Note that attribute names can be specified WITH or WITHOUT
1568  * double underscores, ie const or __const__.
1569  *
1570  * The following attributes are parsed without arguments
1571  *  const
1572  *  volatile
1573  *  cdecl
1574  *  stdcall
1575  *  fastcall
1576  *  deprecated
1577  *  noinline
1578  *  noreturn
1579  *  naked
1580  *  pure
1581  *  always_inline
1582  *  malloc
1583  *  weak
1584  *  constructor
1585  *  destructor
1586  *  nothrow
1587  *  transparent_union
1588  *  common
1589  *  nocommon
1590  *  packed
1591  *  shared
1592  *  notshared
1593  *  used
1594  *  unused
1595  *  no_instrument_function
1596  *  warn_unused_result
1597  *  longcall
1598  *  shortcall
1599  *  long_call
1600  *  short_call
1601  *  function_vector
1602  *  interrupt_handler
1603  *  nmi_handler
1604  *  nesting
1605  *  near
1606  *  far
1607  *  signal
1608  *  eightbit_data
1609  *  tiny_data
1610  *  saveall
1611  *  flatten
1612  *  sseregparm
1613  *  externally_visible
1614  *  return_twice
1615  *  may_alias
1616  *  ms_struct
1617  *  gcc_struct
1618  *  dllimport
1619  *  dllexport
1620  *
1621  * The following attributes are parsed with arguments
1622  *  aligned( const expression )
1623  *  alias( string literal )
1624  *  section( string literal )
1625  *  format( identifier, const expression, const expression )
1626  *  format_arg( const expression )
1627  *  tls_model( string literal )
1628  *  visibility( string literal )
1629  *  regparm( const expression )
1630  *  model( string leteral )
1631  *  trap_exit( const expression )
1632  *  sp_switch( string literal )
1633  *
1634  * The following attributes might have arguments
1635  *  weak_ref( string literal )
1636  *  non_null( const expression // ',' )
1637  *  interrupt( string literal )
1638  *  sentinel( constant expression )
1639  */
1640 static decl_modifiers_t parse_gnu_attribute(gnu_attribute_t **attributes)
1641 {
1642         gnu_attribute_t *head      = *attributes;
1643         gnu_attribute_t *last      = *attributes;
1644         decl_modifiers_t modifiers = 0;
1645         gnu_attribute_t *attribute;
1646
1647         eat(T___attribute__);
1648         expect('(', end_error);
1649         expect('(', end_error);
1650
1651         if (token.type != ')') {
1652                 /* find the end of the list */
1653                 if (last != NULL) {
1654                         while (last->next != NULL)
1655                                 last = last->next;
1656                 }
1657
1658                 /* non-empty attribute list */
1659                 while (true) {
1660                         const char *name;
1661                         if (token.type == T_const) {
1662                                 name = "const";
1663                         } else if (token.type == T_volatile) {
1664                                 name = "volatile";
1665                         } else if (token.type == T_cdecl) {
1666                                 /* __attribute__((cdecl)), WITH ms mode */
1667                                 name = "cdecl";
1668                         } else if (token.type == T_IDENTIFIER) {
1669                                 const symbol_t *sym = token.v.symbol;
1670                                 name = sym->string;
1671                         } else {
1672                                 parse_error_expected("while parsing GNU attribute", T_IDENTIFIER, NULL);
1673                                 break;
1674                         }
1675
1676                         next_token();
1677
1678                         int i;
1679                         for (i = 0; i < GNU_AK_LAST; ++i) {
1680                                 if (strcmp_underscore(gnu_attribute_names[i], name) == 0)
1681                                         break;
1682                         }
1683                         gnu_attribute_kind_t kind = (gnu_attribute_kind_t)i;
1684
1685                         attribute = NULL;
1686                         if (kind == GNU_AK_LAST) {
1687                                 if (warning.attribute)
1688                                         warningf(HERE, "'%s' attribute directive ignored", name);
1689
1690                                 /* skip possible arguments */
1691                                 if (token.type == '(') {
1692                                         eat_until_matching_token(')');
1693                                         next_token(); /* skip the ')' */
1694                                 }
1695                         } else {
1696                                 /* check for arguments */
1697                                 attribute = allocate_gnu_attribute(kind);
1698                                 if (token.type == '(') {
1699                                         next_token();
1700                                         if (token.type == ')') {
1701                                                 /* empty args are allowed */
1702                                                 next_token();
1703                                         } else
1704                                                 attribute->has_arguments = true;
1705                                 }
1706
1707                                 switch (kind) {
1708                                 case GNU_AK_VOLATILE:
1709                                 case GNU_AK_NAKED:
1710                                 case GNU_AK_MALLOC:
1711                                 case GNU_AK_WEAK:
1712                                 case GNU_AK_COMMON:
1713                                 case GNU_AK_NOCOMMON:
1714                                 case GNU_AK_SHARED:
1715                                 case GNU_AK_NOTSHARED:
1716                                 case GNU_AK_NO_INSTRUMENT_FUNCTION:
1717                                 case GNU_AK_WARN_UNUSED_RESULT:
1718                                 case GNU_AK_LONGCALL:
1719                                 case GNU_AK_SHORTCALL:
1720                                 case GNU_AK_LONG_CALL:
1721                                 case GNU_AK_SHORT_CALL:
1722                                 case GNU_AK_FUNCTION_VECTOR:
1723                                 case GNU_AK_INTERRUPT_HANDLER:
1724                                 case GNU_AK_NMI_HANDLER:
1725                                 case GNU_AK_NESTING:
1726                                 case GNU_AK_NEAR:
1727                                 case GNU_AK_FAR:
1728                                 case GNU_AK_SIGNAL:
1729                                 case GNU_AK_EIGTHBIT_DATA:
1730                                 case GNU_AK_TINY_DATA:
1731                                 case GNU_AK_SAVEALL:
1732                                 case GNU_AK_FLATTEN:
1733                                 case GNU_AK_SSEREGPARM:
1734                                 case GNU_AK_EXTERNALLY_VISIBLE:
1735                                 case GNU_AK_RETURN_TWICE:
1736                                 case GNU_AK_MAY_ALIAS:
1737                                 case GNU_AK_MS_STRUCT:
1738                                 case GNU_AK_GCC_STRUCT:
1739                                         goto no_arg;
1740
1741                                 case GNU_AK_CDECL:             modifiers |= DM_CDECL;             goto no_arg;
1742                                 case GNU_AK_FASTCALL:          modifiers |= DM_FASTCALL;          goto no_arg;
1743                                 case GNU_AK_STDCALL:           modifiers |= DM_STDCALL;           goto no_arg;
1744                                 case GNU_AK_UNUSED:            modifiers |= DM_UNUSED;            goto no_arg;
1745                                 case GNU_AK_USED:              modifiers |= DM_USED;              goto no_arg;
1746                                 case GNU_AK_PURE:              modifiers |= DM_PURE;              goto no_arg;
1747                                 case GNU_AK_CONST:             modifiers |= DM_CONST;             goto no_arg;
1748                                 case GNU_AK_ALWAYS_INLINE:     modifiers |= DM_FORCEINLINE;       goto no_arg;
1749                                 case GNU_AK_DLLIMPORT:         modifiers |= DM_DLLIMPORT;         goto no_arg;
1750                                 case GNU_AK_DLLEXPORT:         modifiers |= DM_DLLEXPORT;         goto no_arg;
1751                                 case GNU_AK_PACKED:            modifiers |= DM_PACKED;            goto no_arg;
1752                                 case GNU_AK_NOINLINE:          modifiers |= DM_NOINLINE;          goto no_arg;
1753                                 case GNU_AK_RETURNS_TWICE:     modifiers |= DM_RETURNS_TWICE;     goto no_arg;
1754                                 case GNU_AK_NORETURN:          modifiers |= DM_NORETURN;          goto no_arg;
1755                                 case GNU_AK_NOTHROW:           modifiers |= DM_NOTHROW;           goto no_arg;
1756                                 case GNU_AK_TRANSPARENT_UNION: modifiers |= DM_TRANSPARENT_UNION; goto no_arg;
1757                                 case GNU_AK_CONSTRUCTOR:       modifiers |= DM_CONSTRUCTOR;       goto no_arg;
1758                                 case GNU_AK_DESTRUCTOR:        modifiers |= DM_DESTRUCTOR;        goto no_arg;
1759                                 case GNU_AK_DEPRECATED:        modifiers |= DM_DEPRECATED;        goto no_arg;
1760
1761                                 case GNU_AK_ALIGNED:
1762                                         /* __align__ may be used without an argument */
1763                                         if (attribute->has_arguments) {
1764                                                 parse_gnu_attribute_const_arg(attribute);
1765                                         }
1766                                         break;
1767
1768                                 case GNU_AK_FORMAT_ARG:
1769                                 case GNU_AK_REGPARM:
1770                                 case GNU_AK_TRAP_EXIT:
1771                                         if (!attribute->has_arguments) {
1772                                                 /* should have arguments */
1773                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1774                                                 attribute->invalid = true;
1775                                         } else
1776                                                 parse_gnu_attribute_const_arg(attribute);
1777                                         break;
1778                                 case GNU_AK_ALIAS:
1779                                 case GNU_AK_SECTION:
1780                                 case GNU_AK_SP_SWITCH:
1781                                         if (!attribute->has_arguments) {
1782                                                 /* should have arguments */
1783                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1784                                                 attribute->invalid = true;
1785                                         } else
1786                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1787                                         break;
1788                                 case GNU_AK_FORMAT:
1789                                         if (!attribute->has_arguments) {
1790                                                 /* should have arguments */
1791                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1792                                                 attribute->invalid = true;
1793                                         } else
1794                                                 parse_gnu_attribute_format_args(attribute);
1795                                         break;
1796                                 case GNU_AK_WEAKREF:
1797                                         /* may have one string argument */
1798                                         if (attribute->has_arguments)
1799                                                 parse_gnu_attribute_string_arg(attribute, &attribute->u.string);
1800                                         break;
1801                                 case GNU_AK_NONNULL:
1802                                         if (attribute->has_arguments)
1803                                                 parse_gnu_attribute_const_arg_list(attribute);
1804                                         break;
1805                                 case GNU_AK_TLS_MODEL:
1806                                         if (!attribute->has_arguments) {
1807                                                 /* should have arguments */
1808                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1809                                         } else
1810                                                 parse_gnu_attribute_tls_model_arg(attribute);
1811                                         break;
1812                                 case GNU_AK_VISIBILITY:
1813                                         if (!attribute->has_arguments) {
1814                                                 /* should have arguments */
1815                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1816                                         } else
1817                                                 parse_gnu_attribute_visibility_arg(attribute);
1818                                         break;
1819                                 case GNU_AK_MODEL:
1820                                         if (!attribute->has_arguments) {
1821                                                 /* should have arguments */
1822                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1823                                         } else {
1824                                                 parse_gnu_attribute_model_arg(attribute);
1825                                         }
1826                                         break;
1827                                 case GNU_AK_MODE:
1828                                         if (!attribute->has_arguments) {
1829                                                 /* should have arguments */
1830                                                 errorf(HERE, "wrong number of arguments specified for '%s' attribute", name);
1831                                         } else {
1832                                                 parse_gnu_attribute_mode_arg(attribute);
1833                                         }
1834                                         break;
1835                                 case GNU_AK_INTERRUPT:
1836                                         /* may have one string argument */
1837                                         if (attribute->has_arguments)
1838                                                 parse_gnu_attribute_interrupt_arg(attribute);
1839                                         break;
1840                                 case GNU_AK_SENTINEL:
1841                                         /* may have one string argument */
1842                                         if (attribute->has_arguments)
1843                                                 parse_gnu_attribute_const_arg(attribute);
1844                                         break;
1845                                 case GNU_AK_LAST:
1846                                         /* already handled */
1847                                         break;
1848
1849 no_arg:
1850                                         check_no_argument(attribute, name);
1851                                 }
1852                         }
1853                         if (attribute != NULL) {
1854                                 if (last != NULL) {
1855                                         last->next = attribute;
1856                                         last       = attribute;
1857                                 } else {
1858                                         head = last = attribute;
1859                                 }
1860                         }
1861
1862                         if (token.type != ',')
1863                                 break;
1864                         next_token();
1865                 }
1866         }
1867         expect(')', end_error);
1868         expect(')', end_error);
1869 end_error:
1870         *attributes = head;
1871
1872         return modifiers;
1873 }
1874
1875 /**
1876  * Parse GNU attributes.
1877  */
1878 static decl_modifiers_t parse_attributes(gnu_attribute_t **attributes)
1879 {
1880         decl_modifiers_t modifiers = 0;
1881
1882         while (true) {
1883                 switch (token.type) {
1884                 case T___attribute__:
1885                         modifiers |= parse_gnu_attribute(attributes);
1886                         continue;
1887
1888                 case T_asm:
1889                         next_token();
1890                         expect('(', end_error);
1891                         if (token.type != T_STRING_LITERAL) {
1892                                 parse_error_expected("while parsing assembler attribute",
1893                                                      T_STRING_LITERAL, NULL);
1894                                 eat_until_matching_token('(');
1895                                 break;
1896                         } else {
1897                                 parse_string_literals();
1898                         }
1899                         expect(')', end_error);
1900                         continue;
1901
1902                 case T_cdecl:     modifiers |= DM_CDECL;    break;
1903                 case T__fastcall: modifiers |= DM_FASTCALL; break;
1904                 case T__stdcall:  modifiers |= DM_STDCALL;  break;
1905
1906                 case T___thiscall:
1907                         /* TODO record modifier */
1908                         if (warning.other)
1909                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1910                         break;
1911
1912 end_error:
1913                 default: return modifiers;
1914                 }
1915
1916                 next_token();
1917         }
1918 }
1919
1920 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1921
1922 static entity_t *determine_lhs_ent(expression_t *const expr,
1923                                    entity_t *lhs_ent)
1924 {
1925         switch (expr->kind) {
1926                 case EXPR_REFERENCE: {
1927                         entity_t *const entity = expr->reference.entity;
1928                         /* we should only find variables as lvalues... */
1929                         if (entity->base.kind != ENTITY_VARIABLE
1930                                         && entity->base.kind != ENTITY_PARAMETER)
1931                                 return NULL;
1932
1933                         return entity;
1934                 }
1935
1936                 case EXPR_ARRAY_ACCESS: {
1937                         expression_t *const ref = expr->array_access.array_ref;
1938                         entity_t     *      ent = NULL;
1939                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1940                                 ent     = determine_lhs_ent(ref, lhs_ent);
1941                                 lhs_ent = ent;
1942                         } else {
1943                                 mark_vars_read(expr->select.compound, lhs_ent);
1944                         }
1945                         mark_vars_read(expr->array_access.index, lhs_ent);
1946                         return ent;
1947                 }
1948
1949                 case EXPR_SELECT: {
1950                         if (is_type_compound(skip_typeref(expr->base.type))) {
1951                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1952                         } else {
1953                                 mark_vars_read(expr->select.compound, lhs_ent);
1954                                 return NULL;
1955                         }
1956                 }
1957
1958                 case EXPR_UNARY_DEREFERENCE: {
1959                         expression_t *const val = expr->unary.value;
1960                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1961                                 /* *&x is a NOP */
1962                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1963                         } else {
1964                                 mark_vars_read(val, NULL);
1965                                 return NULL;
1966                         }
1967                 }
1968
1969                 default:
1970                         mark_vars_read(expr, NULL);
1971                         return NULL;
1972         }
1973 }
1974
1975 #define ENT_ANY ((entity_t*)-1)
1976
1977 /**
1978  * Mark declarations, which are read.  This is used to detect variables, which
1979  * are never read.
1980  * Example:
1981  * x = x + 1;
1982  *   x is not marked as "read", because it is only read to calculate its own new
1983  *   value.
1984  *
1985  * x += y; y += x;
1986  *   x and y are not detected as "not read", because multiple variables are
1987  *   involved.
1988  */
1989 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1990 {
1991         switch (expr->kind) {
1992                 case EXPR_REFERENCE: {
1993                         entity_t *const entity = expr->reference.entity;
1994                         if (entity->kind != ENTITY_VARIABLE
1995                                         && entity->kind != ENTITY_PARAMETER)
1996                                 return;
1997
1998                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1999                                 if (entity->kind == ENTITY_VARIABLE) {
2000                                         entity->variable.read = true;
2001                                 } else {
2002                                         entity->parameter.read = true;
2003                                 }
2004                         }
2005                         return;
2006                 }
2007
2008                 case EXPR_CALL:
2009                         // TODO respect pure/const
2010                         mark_vars_read(expr->call.function, NULL);
2011                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
2012                                 mark_vars_read(arg->expression, NULL);
2013                         }
2014                         return;
2015
2016                 case EXPR_CONDITIONAL:
2017                         // TODO lhs_decl should depend on whether true/false have an effect
2018                         mark_vars_read(expr->conditional.condition, NULL);
2019                         if (expr->conditional.true_expression != NULL)
2020                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
2021                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
2022                         return;
2023
2024                 case EXPR_SELECT:
2025                         if (lhs_ent == ENT_ANY
2026                                         && !is_type_compound(skip_typeref(expr->base.type)))
2027                                 lhs_ent = NULL;
2028                         mark_vars_read(expr->select.compound, lhs_ent);
2029                         return;
2030
2031                 case EXPR_ARRAY_ACCESS: {
2032                         expression_t *const ref = expr->array_access.array_ref;
2033                         mark_vars_read(ref, lhs_ent);
2034                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
2035                         mark_vars_read(expr->array_access.index, lhs_ent);
2036                         return;
2037                 }
2038
2039                 case EXPR_VA_ARG:
2040                         mark_vars_read(expr->va_arge.ap, lhs_ent);
2041                         return;
2042
2043                 case EXPR_VA_COPY:
2044                         mark_vars_read(expr->va_copye.src, lhs_ent);
2045                         return;
2046
2047                 case EXPR_UNARY_CAST:
2048                         /* Special case: Use void cast to mark a variable as "read" */
2049                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
2050                                 lhs_ent = NULL;
2051                         goto unary;
2052
2053
2054                 case EXPR_UNARY_THROW:
2055                         if (expr->unary.value == NULL)
2056                                 return;
2057                         /* FALLTHROUGH */
2058                 case EXPR_UNARY_DEREFERENCE:
2059                 case EXPR_UNARY_DELETE:
2060                 case EXPR_UNARY_DELETE_ARRAY:
2061                         if (lhs_ent == ENT_ANY)
2062                                 lhs_ent = NULL;
2063                         goto unary;
2064
2065                 case EXPR_UNARY_NEGATE:
2066                 case EXPR_UNARY_PLUS:
2067                 case EXPR_UNARY_BITWISE_NEGATE:
2068                 case EXPR_UNARY_NOT:
2069                 case EXPR_UNARY_TAKE_ADDRESS:
2070                 case EXPR_UNARY_POSTFIX_INCREMENT:
2071                 case EXPR_UNARY_POSTFIX_DECREMENT:
2072                 case EXPR_UNARY_PREFIX_INCREMENT:
2073                 case EXPR_UNARY_PREFIX_DECREMENT:
2074                 case EXPR_UNARY_CAST_IMPLICIT:
2075                 case EXPR_UNARY_ASSUME:
2076 unary:
2077                         mark_vars_read(expr->unary.value, lhs_ent);
2078                         return;
2079
2080                 case EXPR_BINARY_ADD:
2081                 case EXPR_BINARY_SUB:
2082                 case EXPR_BINARY_MUL:
2083                 case EXPR_BINARY_DIV:
2084                 case EXPR_BINARY_MOD:
2085                 case EXPR_BINARY_EQUAL:
2086                 case EXPR_BINARY_NOTEQUAL:
2087                 case EXPR_BINARY_LESS:
2088                 case EXPR_BINARY_LESSEQUAL:
2089                 case EXPR_BINARY_GREATER:
2090                 case EXPR_BINARY_GREATEREQUAL:
2091                 case EXPR_BINARY_BITWISE_AND:
2092                 case EXPR_BINARY_BITWISE_OR:
2093                 case EXPR_BINARY_BITWISE_XOR:
2094                 case EXPR_BINARY_LOGICAL_AND:
2095                 case EXPR_BINARY_LOGICAL_OR:
2096                 case EXPR_BINARY_SHIFTLEFT:
2097                 case EXPR_BINARY_SHIFTRIGHT:
2098                 case EXPR_BINARY_COMMA:
2099                 case EXPR_BINARY_ISGREATER:
2100                 case EXPR_BINARY_ISGREATEREQUAL:
2101                 case EXPR_BINARY_ISLESS:
2102                 case EXPR_BINARY_ISLESSEQUAL:
2103                 case EXPR_BINARY_ISLESSGREATER:
2104                 case EXPR_BINARY_ISUNORDERED:
2105                         mark_vars_read(expr->binary.left,  lhs_ent);
2106                         mark_vars_read(expr->binary.right, lhs_ent);
2107                         return;
2108
2109                 case EXPR_BINARY_ASSIGN:
2110                 case EXPR_BINARY_MUL_ASSIGN:
2111                 case EXPR_BINARY_DIV_ASSIGN:
2112                 case EXPR_BINARY_MOD_ASSIGN:
2113                 case EXPR_BINARY_ADD_ASSIGN:
2114                 case EXPR_BINARY_SUB_ASSIGN:
2115                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
2116                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
2117                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
2118                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
2119                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
2120                         if (lhs_ent == ENT_ANY)
2121                                 lhs_ent = NULL;
2122                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
2123                         mark_vars_read(expr->binary.right, lhs_ent);
2124                         return;
2125                 }
2126
2127                 case EXPR_VA_START:
2128                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
2129                         return;
2130
2131                 case EXPR_UNKNOWN:
2132                 case EXPR_INVALID:
2133                 case EXPR_CONST:
2134                 case EXPR_CHARACTER_CONSTANT:
2135                 case EXPR_WIDE_CHARACTER_CONSTANT:
2136                 case EXPR_STRING_LITERAL:
2137                 case EXPR_WIDE_STRING_LITERAL:
2138                 case EXPR_COMPOUND_LITERAL: // TODO init?
2139                 case EXPR_SIZEOF:
2140                 case EXPR_CLASSIFY_TYPE:
2141                 case EXPR_ALIGNOF:
2142                 case EXPR_FUNCNAME:
2143                 case EXPR_BUILTIN_CONSTANT_P:
2144                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
2145                 case EXPR_OFFSETOF:
2146                 case EXPR_STATEMENT: // TODO
2147                 case EXPR_LABEL_ADDRESS:
2148                 case EXPR_REFERENCE_ENUM_VALUE:
2149                         return;
2150         }
2151
2152         panic("unhandled expression");
2153 }
2154
2155 static designator_t *parse_designation(void)
2156 {
2157         designator_t *result = NULL;
2158         designator_t *last   = NULL;
2159
2160         while (true) {
2161                 designator_t *designator;
2162                 switch (token.type) {
2163                 case '[':
2164                         designator = allocate_ast_zero(sizeof(designator[0]));
2165                         designator->source_position = token.source_position;
2166                         next_token();
2167                         add_anchor_token(']');
2168                         designator->array_index = parse_constant_expression();
2169                         rem_anchor_token(']');
2170                         expect(']', end_error);
2171                         break;
2172                 case '.':
2173                         designator = allocate_ast_zero(sizeof(designator[0]));
2174                         designator->source_position = token.source_position;
2175                         next_token();
2176                         if (token.type != T_IDENTIFIER) {
2177                                 parse_error_expected("while parsing designator",
2178                                                      T_IDENTIFIER, NULL);
2179                                 return NULL;
2180                         }
2181                         designator->symbol = token.v.symbol;
2182                         next_token();
2183                         break;
2184                 default:
2185                         expect('=', end_error);
2186                         return result;
2187                 }
2188
2189                 assert(designator != NULL);
2190                 if (last != NULL) {
2191                         last->next = designator;
2192                 } else {
2193                         result = designator;
2194                 }
2195                 last = designator;
2196         }
2197 end_error:
2198         return NULL;
2199 }
2200
2201 static initializer_t *initializer_from_string(array_type_t *type,
2202                                               const string_t *const string)
2203 {
2204         /* TODO: check len vs. size of array type */
2205         (void) type;
2206
2207         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
2208         initializer->string.string = *string;
2209
2210         return initializer;
2211 }
2212
2213 static initializer_t *initializer_from_wide_string(array_type_t *const type,
2214                                                    wide_string_t *const string)
2215 {
2216         /* TODO: check len vs. size of array type */
2217         (void) type;
2218
2219         initializer_t *const initializer =
2220                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
2221         initializer->wide_string.string = *string;
2222
2223         return initializer;
2224 }
2225
2226 /**
2227  * Build an initializer from a given expression.
2228  */
2229 static initializer_t *initializer_from_expression(type_t *orig_type,
2230                                                   expression_t *expression)
2231 {
2232         /* TODO check that expression is a constant expression */
2233
2234         /* §6.7.8.14/15 char array may be initialized by string literals */
2235         type_t *type           = skip_typeref(orig_type);
2236         type_t *expr_type_orig = expression->base.type;
2237         type_t *expr_type      = skip_typeref(expr_type_orig);
2238         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
2239                 array_type_t *const array_type   = &type->array;
2240                 type_t       *const element_type = skip_typeref(array_type->element_type);
2241
2242                 if (element_type->kind == TYPE_ATOMIC) {
2243                         atomic_type_kind_t akind = element_type->atomic.akind;
2244                         switch (expression->kind) {
2245                                 case EXPR_STRING_LITERAL:
2246                                         if (akind == ATOMIC_TYPE_CHAR
2247                                                         || akind == ATOMIC_TYPE_SCHAR
2248                                                         || akind == ATOMIC_TYPE_UCHAR) {
2249                                                 return initializer_from_string(array_type,
2250                                                         &expression->string.value);
2251                                         }
2252                                         break;
2253
2254                                 case EXPR_WIDE_STRING_LITERAL: {
2255                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
2256                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
2257                                                 return initializer_from_wide_string(array_type,
2258                                                         &expression->wide_string.value);
2259                                         }
2260                                         break;
2261                                 }
2262
2263                                 default:
2264                                         break;
2265                         }
2266                 }
2267         }
2268
2269         assign_error_t error = semantic_assign(type, expression);
2270         if (error == ASSIGN_ERROR_INCOMPATIBLE)
2271                 return NULL;
2272         report_assign_error(error, type, expression, "initializer",
2273                             &expression->base.source_position);
2274
2275         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
2276 #if 0
2277         if (type->kind == TYPE_BITFIELD) {
2278                 type = type->bitfield.base_type;
2279         }
2280 #endif
2281         result->value.value = create_implicit_cast(expression, type);
2282
2283         return result;
2284 }
2285
2286 /**
2287  * Checks if a given expression can be used as an constant initializer.
2288  */
2289 static bool is_initializer_constant(const expression_t *expression)
2290 {
2291         return is_constant_expression(expression)
2292                 || is_address_constant(expression);
2293 }
2294
2295 /**
2296  * Parses an scalar initializer.
2297  *
2298  * §6.7.8.11; eat {} without warning
2299  */
2300 static initializer_t *parse_scalar_initializer(type_t *type,
2301                                                bool must_be_constant)
2302 {
2303         /* there might be extra {} hierarchies */
2304         int braces = 0;
2305         if (token.type == '{') {
2306                 if (warning.other)
2307                         warningf(HERE, "extra curly braces around scalar initializer");
2308                 do {
2309                         ++braces;
2310                         next_token();
2311                 } while (token.type == '{');
2312         }
2313
2314         expression_t *expression = parse_assignment_expression();
2315         mark_vars_read(expression, NULL);
2316         if (must_be_constant && !is_initializer_constant(expression)) {
2317                 errorf(&expression->base.source_position,
2318                        "Initialisation expression '%E' is not constant",
2319                        expression);
2320         }
2321
2322         initializer_t *initializer = initializer_from_expression(type, expression);
2323
2324         if (initializer == NULL) {
2325                 errorf(&expression->base.source_position,
2326                        "expression '%E' (type '%T') doesn't match expected type '%T'",
2327                        expression, expression->base.type, type);
2328                 /* TODO */
2329                 return NULL;
2330         }
2331
2332         bool additional_warning_displayed = false;
2333         while (braces > 0) {
2334                 if (token.type == ',') {
2335                         next_token();
2336                 }
2337                 if (token.type != '}') {
2338                         if (!additional_warning_displayed && warning.other) {
2339                                 warningf(HERE, "additional elements in scalar initializer");
2340                                 additional_warning_displayed = true;
2341                         }
2342                 }
2343                 eat_block();
2344                 braces--;
2345         }
2346
2347         return initializer;
2348 }
2349
2350 /**
2351  * An entry in the type path.
2352  */
2353 typedef struct type_path_entry_t type_path_entry_t;
2354 struct type_path_entry_t {
2355         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
2356         union {
2357                 size_t         index;          /**< For array types: the current index. */
2358                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
2359         } v;
2360 };
2361
2362 /**
2363  * A type path expression a position inside compound or array types.
2364  */
2365 typedef struct type_path_t type_path_t;
2366 struct type_path_t {
2367         type_path_entry_t *path;         /**< An flexible array containing the current path. */
2368         type_t            *top_type;     /**< type of the element the path points */
2369         size_t             max_index;    /**< largest index in outermost array */
2370 };
2371
2372 /**
2373  * Prints a type path for debugging.
2374  */
2375 static __attribute__((unused)) void debug_print_type_path(
2376                 const type_path_t *path)
2377 {
2378         size_t len = ARR_LEN(path->path);
2379
2380         for (size_t i = 0; i < len; ++i) {
2381                 const type_path_entry_t *entry = & path->path[i];
2382
2383                 type_t *type = skip_typeref(entry->type);
2384                 if (is_type_compound(type)) {
2385                         /* in gcc mode structs can have no members */
2386                         if (entry->v.compound_entry == NULL) {
2387                                 assert(i == len-1);
2388                                 continue;
2389                         }
2390                         fprintf(stderr, ".%s",
2391                                 entry->v.compound_entry->base.symbol->string);
2392                 } else if (is_type_array(type)) {
2393                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
2394                 } else {
2395                         fprintf(stderr, "-INVALID-");
2396                 }
2397         }
2398         if (path->top_type != NULL) {
2399                 fprintf(stderr, "  (");
2400                 print_type(path->top_type);
2401                 fprintf(stderr, ")");
2402         }
2403 }
2404
2405 /**
2406  * Return the top type path entry, ie. in a path
2407  * (type).a.b returns the b.
2408  */
2409 static type_path_entry_t *get_type_path_top(const type_path_t *path)
2410 {
2411         size_t len = ARR_LEN(path->path);
2412         assert(len > 0);
2413         return &path->path[len-1];
2414 }
2415
2416 /**
2417  * Enlarge the type path by an (empty) element.
2418  */
2419 static type_path_entry_t *append_to_type_path(type_path_t *path)
2420 {
2421         size_t len = ARR_LEN(path->path);
2422         ARR_RESIZE(type_path_entry_t, path->path, len+1);
2423
2424         type_path_entry_t *result = & path->path[len];
2425         memset(result, 0, sizeof(result[0]));
2426         return result;
2427 }
2428
2429 /**
2430  * Descending into a sub-type. Enter the scope of the current top_type.
2431  */
2432 static void descend_into_subtype(type_path_t *path)
2433 {
2434         type_t *orig_top_type = path->top_type;
2435         type_t *top_type      = skip_typeref(orig_top_type);
2436
2437         type_path_entry_t *top = append_to_type_path(path);
2438         top->type              = top_type;
2439
2440         if (is_type_compound(top_type)) {
2441                 compound_t *compound  = top_type->compound.compound;
2442                 entity_t   *entry     = compound->members.entities;
2443
2444                 if (entry != NULL) {
2445                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
2446                         top->v.compound_entry = &entry->declaration;
2447                         path->top_type = entry->declaration.type;
2448                 } else {
2449                         path->top_type = NULL;
2450                 }
2451         } else if (is_type_array(top_type)) {
2452                 top->v.index   = 0;
2453                 path->top_type = top_type->array.element_type;
2454         } else {
2455                 assert(!is_type_valid(top_type));
2456         }
2457 }
2458
2459 /**
2460  * Pop an entry from the given type path, ie. returning from
2461  * (type).a.b to (type).a
2462  */
2463 static void ascend_from_subtype(type_path_t *path)
2464 {
2465         type_path_entry_t *top = get_type_path_top(path);
2466
2467         path->top_type = top->type;
2468
2469         size_t len = ARR_LEN(path->path);
2470         ARR_RESIZE(type_path_entry_t, path->path, len-1);
2471 }
2472
2473 /**
2474  * Pop entries from the given type path until the given
2475  * path level is reached.
2476  */
2477 static void ascend_to(type_path_t *path, size_t top_path_level)
2478 {
2479         size_t len = ARR_LEN(path->path);
2480
2481         while (len > top_path_level) {
2482                 ascend_from_subtype(path);
2483                 len = ARR_LEN(path->path);
2484         }
2485 }
2486
2487 static bool walk_designator(type_path_t *path, const designator_t *designator,
2488                             bool used_in_offsetof)
2489 {
2490         for (; designator != NULL; designator = designator->next) {
2491                 type_path_entry_t *top       = get_type_path_top(path);
2492                 type_t            *orig_type = top->type;
2493
2494                 type_t *type = skip_typeref(orig_type);
2495
2496                 if (designator->symbol != NULL) {
2497                         symbol_t *symbol = designator->symbol;
2498                         if (!is_type_compound(type)) {
2499                                 if (is_type_valid(type)) {
2500                                         errorf(&designator->source_position,
2501                                                "'.%Y' designator used for non-compound type '%T'",
2502                                                symbol, orig_type);
2503                                 }
2504
2505                                 top->type             = type_error_type;
2506                                 top->v.compound_entry = NULL;
2507                                 orig_type             = type_error_type;
2508                         } else {
2509                                 compound_t *compound = type->compound.compound;
2510                                 entity_t   *iter     = compound->members.entities;
2511                                 for (; iter != NULL; iter = iter->base.next) {
2512                                         if (iter->base.symbol == symbol) {
2513                                                 break;
2514                                         }
2515                                 }
2516                                 if (iter == NULL) {
2517                                         errorf(&designator->source_position,
2518                                                "'%T' has no member named '%Y'", orig_type, symbol);
2519                                         goto failed;
2520                                 }
2521                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
2522                                 if (used_in_offsetof) {
2523                                         type_t *real_type = skip_typeref(iter->declaration.type);
2524                                         if (real_type->kind == TYPE_BITFIELD) {
2525                                                 errorf(&designator->source_position,
2526                                                        "offsetof designator '%Y' may not specify bitfield",
2527                                                        symbol);
2528                                                 goto failed;
2529                                         }
2530                                 }
2531
2532                                 top->type             = orig_type;
2533                                 top->v.compound_entry = &iter->declaration;
2534                                 orig_type             = iter->declaration.type;
2535                         }
2536                 } else {
2537                         expression_t *array_index = designator->array_index;
2538                         assert(designator->array_index != NULL);
2539
2540                         if (!is_type_array(type)) {
2541                                 if (is_type_valid(type)) {
2542                                         errorf(&designator->source_position,
2543                                                "[%E] designator used for non-array type '%T'",
2544                                                array_index, orig_type);
2545                                 }
2546                                 goto failed;
2547                         }
2548
2549                         long index = fold_constant(array_index);
2550                         if (!used_in_offsetof) {
2551                                 if (index < 0) {
2552                                         errorf(&designator->source_position,
2553                                                "array index [%E] must be positive", array_index);
2554                                 } else if (type->array.size_constant) {
2555                                         long array_size = type->array.size;
2556                                         if (index >= array_size) {
2557                                                 errorf(&designator->source_position,
2558                                                        "designator [%E] (%d) exceeds array size %d",
2559                                                        array_index, index, array_size);
2560                                         }
2561                                 }
2562                         }
2563
2564                         top->type    = orig_type;
2565                         top->v.index = (size_t) index;
2566                         orig_type    = type->array.element_type;
2567                 }
2568                 path->top_type = orig_type;
2569
2570                 if (designator->next != NULL) {
2571                         descend_into_subtype(path);
2572                 }
2573         }
2574         return true;
2575
2576 failed:
2577         return false;
2578 }
2579
2580 static void advance_current_object(type_path_t *path, size_t top_path_level)
2581 {
2582         type_path_entry_t *top = get_type_path_top(path);
2583
2584         type_t *type = skip_typeref(top->type);
2585         if (is_type_union(type)) {
2586                 /* in unions only the first element is initialized */
2587                 top->v.compound_entry = NULL;
2588         } else if (is_type_struct(type)) {
2589                 declaration_t *entry = top->v.compound_entry;
2590
2591                 entity_t *next_entity = entry->base.next;
2592                 if (next_entity != NULL) {
2593                         assert(is_declaration(next_entity));
2594                         entry = &next_entity->declaration;
2595                 } else {
2596                         entry = NULL;
2597                 }
2598
2599                 top->v.compound_entry = entry;
2600                 if (entry != NULL) {
2601                         path->top_type = entry->type;
2602                         return;
2603                 }
2604         } else if (is_type_array(type)) {
2605                 assert(is_type_array(type));
2606
2607                 top->v.index++;
2608
2609                 if (!type->array.size_constant || top->v.index < type->array.size) {
2610                         return;
2611                 }
2612         } else {
2613                 assert(!is_type_valid(type));
2614                 return;
2615         }
2616
2617         /* we're past the last member of the current sub-aggregate, try if we
2618          * can ascend in the type hierarchy and continue with another subobject */
2619         size_t len = ARR_LEN(path->path);
2620
2621         if (len > top_path_level) {
2622                 ascend_from_subtype(path);
2623                 advance_current_object(path, top_path_level);
2624         } else {
2625                 path->top_type = NULL;
2626         }
2627 }
2628
2629 /**
2630  * skip until token is found.
2631  */
2632 static void skip_until(int type)
2633 {
2634         while (token.type != type) {
2635                 if (token.type == T_EOF)
2636                         return;
2637                 next_token();
2638         }
2639 }
2640
2641 /**
2642  * skip any {...} blocks until a closing bracket is reached.
2643  */
2644 static void skip_initializers(void)
2645 {
2646         if (token.type == '{')
2647                 next_token();
2648
2649         while (token.type != '}') {
2650                 if (token.type == T_EOF)
2651                         return;
2652                 if (token.type == '{') {
2653                         eat_block();
2654                         continue;
2655                 }
2656                 next_token();
2657         }
2658 }
2659
2660 static initializer_t *create_empty_initializer(void)
2661 {
2662         static initializer_t empty_initializer
2663                 = { .list = { { INITIALIZER_LIST }, 0 } };
2664         return &empty_initializer;
2665 }
2666
2667 /**
2668  * Parse a part of an initialiser for a struct or union,
2669  */
2670 static initializer_t *parse_sub_initializer(type_path_t *path,
2671                 type_t *outer_type, size_t top_path_level,
2672                 parse_initializer_env_t *env)
2673 {
2674         if (token.type == '}') {
2675                 /* empty initializer */
2676                 return create_empty_initializer();
2677         }
2678
2679         type_t *orig_type = path->top_type;
2680         type_t *type      = NULL;
2681
2682         if (orig_type == NULL) {
2683                 /* We are initializing an empty compound. */
2684         } else {
2685                 type = skip_typeref(orig_type);
2686         }
2687
2688         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2689
2690         while (true) {
2691                 designator_t *designator = NULL;
2692                 if (token.type == '.' || token.type == '[') {
2693                         designator = parse_designation();
2694                         goto finish_designator;
2695                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2696                         /* GNU-style designator ("identifier: value") */
2697                         designator = allocate_ast_zero(sizeof(designator[0]));
2698                         designator->source_position = token.source_position;
2699                         designator->symbol          = token.v.symbol;
2700                         eat(T_IDENTIFIER);
2701                         eat(':');
2702
2703 finish_designator:
2704                         /* reset path to toplevel, evaluate designator from there */
2705                         ascend_to(path, top_path_level);
2706                         if (!walk_designator(path, designator, false)) {
2707                                 /* can't continue after designation error */
2708                                 goto end_error;
2709                         }
2710
2711                         initializer_t *designator_initializer
2712                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2713                         designator_initializer->designator.designator = designator;
2714                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2715
2716                         orig_type = path->top_type;
2717                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2718                 }
2719
2720                 initializer_t *sub;
2721
2722                 if (token.type == '{') {
2723                         if (type != NULL && is_type_scalar(type)) {
2724                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2725                         } else {
2726                                 eat('{');
2727                                 if (type == NULL) {
2728                                         if (env->entity != NULL) {
2729                                                 errorf(HERE,
2730                                                      "extra brace group at end of initializer for '%Y'",
2731                                                      env->entity->base.symbol);
2732                                         } else {
2733                                                 errorf(HERE, "extra brace group at end of initializer");
2734                                         }
2735                                 } else
2736                                         descend_into_subtype(path);
2737
2738                                 add_anchor_token('}');
2739                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2740                                                             env);
2741                                 rem_anchor_token('}');
2742
2743                                 if (type != NULL) {
2744                                         ascend_from_subtype(path);
2745                                         expect('}', end_error);
2746                                 } else {
2747                                         expect('}', end_error);
2748                                         goto error_parse_next;
2749                                 }
2750                         }
2751                 } else {
2752                         /* must be an expression */
2753                         expression_t *expression = parse_assignment_expression();
2754                         mark_vars_read(expression, NULL);
2755
2756                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2757                                 errorf(&expression->base.source_position,
2758                                        "Initialisation expression '%E' is not constant",
2759                                        expression);
2760                         }
2761
2762                         if (type == NULL) {
2763                                 /* we are already outside, ... */
2764                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2765                                 if (is_type_compound(outer_type_skip) &&
2766                                     !outer_type_skip->compound.compound->complete) {
2767                                         goto error_parse_next;
2768                                 }
2769                                 goto error_excess;
2770                         }
2771
2772                         /* handle { "string" } special case */
2773                         if ((expression->kind == EXPR_STRING_LITERAL
2774                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2775                                         && outer_type != NULL) {
2776                                 sub = initializer_from_expression(outer_type, expression);
2777                                 if (sub != NULL) {
2778                                         if (token.type == ',') {
2779                                                 next_token();
2780                                         }
2781                                         if (token.type != '}' && warning.other) {
2782                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2783                                                                  orig_type);
2784                                         }
2785                                         /* TODO: eat , ... */
2786                                         return sub;
2787                                 }
2788                         }
2789
2790                         /* descend into subtypes until expression matches type */
2791                         while (true) {
2792                                 orig_type = path->top_type;
2793                                 type      = skip_typeref(orig_type);
2794
2795                                 sub = initializer_from_expression(orig_type, expression);
2796                                 if (sub != NULL) {
2797                                         break;
2798                                 }
2799                                 if (!is_type_valid(type)) {
2800                                         goto end_error;
2801                                 }
2802                                 if (is_type_scalar(type)) {
2803                                         errorf(&expression->base.source_position,
2804                                                         "expression '%E' doesn't match expected type '%T'",
2805                                                         expression, orig_type);
2806                                         goto end_error;
2807                                 }
2808
2809                                 descend_into_subtype(path);
2810                         }
2811                 }
2812
2813                 /* update largest index of top array */
2814                 const type_path_entry_t *first      = &path->path[0];
2815                 type_t                  *first_type = first->type;
2816                 first_type                          = skip_typeref(first_type);
2817                 if (is_type_array(first_type)) {
2818                         size_t index = first->v.index;
2819                         if (index > path->max_index)
2820                                 path->max_index = index;
2821                 }
2822
2823                 if (type != NULL) {
2824                         /* append to initializers list */
2825                         ARR_APP1(initializer_t*, initializers, sub);
2826                 } else {
2827 error_excess:
2828                         if (warning.other) {
2829                                 if (env->entity != NULL) {
2830                                         warningf(HERE, "excess elements in struct initializer for '%Y'",
2831                                            env->entity->base.symbol);
2832                                 } else {
2833                                         warningf(HERE, "excess elements in struct initializer");
2834                                 }
2835                         }
2836                 }
2837
2838 error_parse_next:
2839                 if (token.type == '}') {
2840                         break;
2841                 }
2842                 expect(',', end_error);
2843                 if (token.type == '}') {
2844                         break;
2845                 }
2846
2847                 if (type != NULL) {
2848                         /* advance to the next declaration if we are not at the end */
2849                         advance_current_object(path, top_path_level);
2850                         orig_type = path->top_type;
2851                         if (orig_type != NULL)
2852                                 type = skip_typeref(orig_type);
2853                         else
2854                                 type = NULL;
2855                 }
2856         }
2857
2858         size_t len  = ARR_LEN(initializers);
2859         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2860         initializer_t *result = allocate_ast_zero(size);
2861         result->kind          = INITIALIZER_LIST;
2862         result->list.len      = len;
2863         memcpy(&result->list.initializers, initializers,
2864                len * sizeof(initializers[0]));
2865
2866         DEL_ARR_F(initializers);
2867         ascend_to(path, top_path_level+1);
2868
2869         return result;
2870
2871 end_error:
2872         skip_initializers();
2873         DEL_ARR_F(initializers);
2874         ascend_to(path, top_path_level+1);
2875         return NULL;
2876 }
2877
2878 /**
2879  * Parses an initializer. Parsers either a compound literal
2880  * (env->declaration == NULL) or an initializer of a declaration.
2881  */
2882 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2883 {
2884         type_t        *type      = skip_typeref(env->type);
2885         size_t         max_index = 0xdeadbeaf;   // TODO: Resolve this uninitialized variable problem
2886         initializer_t *result;
2887
2888         if (is_type_scalar(type)) {
2889                 result = parse_scalar_initializer(type, env->must_be_constant);
2890         } else if (token.type == '{') {
2891                 eat('{');
2892
2893                 type_path_t path;
2894                 memset(&path, 0, sizeof(path));
2895                 path.top_type = env->type;
2896                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2897
2898                 descend_into_subtype(&path);
2899
2900                 add_anchor_token('}');
2901                 result = parse_sub_initializer(&path, env->type, 1, env);
2902                 rem_anchor_token('}');
2903
2904                 max_index = path.max_index;
2905                 DEL_ARR_F(path.path);
2906
2907                 expect('}', end_error);
2908         } else {
2909                 /* parse_scalar_initializer() also works in this case: we simply
2910                  * have an expression without {} around it */
2911                 result = parse_scalar_initializer(type, env->must_be_constant);
2912         }
2913
2914         /* §6.7.8:22 array initializers for arrays with unknown size determine
2915          * the array type size */
2916         if (is_type_array(type) && type->array.size_expression == NULL
2917                         && result != NULL) {
2918                 size_t size;
2919                 switch (result->kind) {
2920                 case INITIALIZER_LIST:
2921                         assert(max_index != 0xdeadbeaf);
2922                         size = max_index + 1;
2923                         break;
2924
2925                 case INITIALIZER_STRING:
2926                         size = result->string.string.size;
2927                         break;
2928
2929                 case INITIALIZER_WIDE_STRING:
2930                         size = result->wide_string.string.size;
2931                         break;
2932
2933                 case INITIALIZER_DESIGNATOR:
2934                 case INITIALIZER_VALUE:
2935                         /* can happen for parse errors */
2936                         size = 0;
2937                         break;
2938
2939                 default:
2940                         internal_errorf(HERE, "invalid initializer type");
2941                 }
2942
2943                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2944                 cnst->base.type          = type_size_t;
2945                 cnst->conste.v.int_value = size;
2946
2947                 type_t *new_type = duplicate_type(type);
2948
2949                 new_type->array.size_expression   = cnst;
2950                 new_type->array.size_constant     = true;
2951                 new_type->array.has_implicit_size = true;
2952                 new_type->array.size              = size;
2953                 env->type = new_type;
2954         }
2955
2956         return result;
2957 end_error:
2958         return NULL;
2959 }
2960
2961 static void append_entity(scope_t *scope, entity_t *entity)
2962 {
2963         if (scope->last_entity != NULL) {
2964                 scope->last_entity->base.next = entity;
2965         } else {
2966                 scope->entities = entity;
2967         }
2968         scope->last_entity = entity;
2969 }
2970
2971
2972 static compound_t *parse_compound_type_specifier(bool is_struct)
2973 {
2974         gnu_attribute_t  *attributes = NULL;
2975         decl_modifiers_t  modifiers  = 0;
2976         if (is_struct) {
2977                 eat(T_struct);
2978         } else {
2979                 eat(T_union);
2980         }
2981
2982         symbol_t   *symbol   = NULL;
2983         compound_t *compound = NULL;
2984
2985         if (token.type == T___attribute__) {
2986                 modifiers |= parse_attributes(&attributes);
2987         }
2988
2989         if (token.type == T_IDENTIFIER) {
2990                 /* the compound has a name, check if we have seen it already */
2991                 symbol = token.v.symbol;
2992                 next_token();
2993
2994                 namespace_tag_t const namespc =
2995                         is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION;
2996                 entity_t *entity = get_entity(symbol, namespc);
2997                 if (entity != NULL) {
2998                         assert(entity->kind == (is_struct ? ENTITY_STRUCT : ENTITY_UNION));
2999                         compound = &entity->compound;
3000                         if (compound->base.parent_scope != current_scope &&
3001                             (token.type == '{' || token.type == ';')) {
3002                                 /* we're in an inner scope and have a definition. Shadow
3003                                  * existing definition in outer scope */
3004                                 compound = NULL;
3005                         } else if (compound->complete && token.type == '{') {
3006                                 assert(symbol != NULL);
3007                                 errorf(HERE, "multiple definitions of '%s %Y' (previous definition %P)",
3008                                        is_struct ? "struct" : "union", symbol,
3009                                        &compound->base.source_position);
3010                                 /* clear members in the hope to avoid further errors */
3011                                 compound->members.entities = NULL;
3012                         }
3013                 }
3014         } else if (token.type != '{') {
3015                 if (is_struct) {
3016                         parse_error_expected("while parsing struct type specifier",
3017                                              T_IDENTIFIER, '{', NULL);
3018                 } else {
3019                         parse_error_expected("while parsing union type specifier",
3020                                              T_IDENTIFIER, '{', NULL);
3021                 }
3022
3023                 return NULL;
3024         }
3025
3026         if (compound == NULL) {
3027                 entity_kind_t  kind   = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
3028                 entity_t      *entity = allocate_entity_zero(kind);
3029                 compound              = &entity->compound;
3030
3031                 compound->base.namespc =
3032                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
3033                 compound->base.source_position = token.source_position;
3034                 compound->base.symbol          = symbol;
3035                 compound->base.parent_scope    = current_scope;
3036                 if (symbol != NULL) {
3037                         environment_push(entity);
3038                 }
3039                 append_entity(current_scope, entity);
3040         }
3041
3042         if (token.type == '{') {
3043                 parse_compound_type_entries(compound);
3044                 modifiers |= parse_attributes(&attributes);
3045
3046                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
3047                 if (symbol == NULL) {
3048                         assert(anonymous_entity == NULL);
3049                         anonymous_entity = (entity_t*)compound;
3050                 }
3051         }
3052
3053         compound->modifiers |= modifiers;
3054         return compound;
3055 }
3056
3057 static void parse_enum_entries(type_t *const enum_type)
3058 {
3059         eat('{');
3060
3061         if (token.type == '}') {
3062                 errorf(HERE, "empty enum not allowed");
3063                 next_token();
3064                 return;
3065         }
3066
3067         add_anchor_token('}');
3068         do {
3069                 if (token.type != T_IDENTIFIER) {
3070                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3071                         eat_block();
3072                         rem_anchor_token('}');
3073                         return;
3074                 }
3075
3076                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3077                 entity->enum_value.enum_type = enum_type;
3078                 entity->base.symbol          = token.v.symbol;
3079                 entity->base.source_position = token.source_position;
3080                 next_token();
3081
3082                 if (token.type == '=') {
3083                         next_token();
3084                         expression_t *value = parse_constant_expression();
3085
3086                         value = create_implicit_cast(value, enum_type);
3087                         entity->enum_value.value = value;
3088
3089                         /* TODO semantic */
3090                 }
3091
3092                 record_entity(entity, false);
3093
3094                 if (token.type != ',')
3095                         break;
3096                 next_token();
3097         } while (token.type != '}');
3098         rem_anchor_token('}');
3099
3100         expect('}', end_error);
3101
3102 end_error:
3103         ;
3104 }
3105
3106 static type_t *parse_enum_specifier(void)
3107 {
3108         gnu_attribute_t *attributes = NULL;
3109         entity_t        *entity;
3110         symbol_t        *symbol;
3111
3112         eat(T_enum);
3113         if (token.type == T_IDENTIFIER) {
3114                 symbol = token.v.symbol;
3115                 next_token();
3116
3117                 entity = get_entity(symbol, NAMESPACE_ENUM);
3118                 if (entity != NULL) {
3119                         assert(entity->kind == ENTITY_ENUM);
3120                         if (entity->base.parent_scope != current_scope &&
3121                                         (token.type == '{' || token.type == ';')) {
3122                                 /* we're in an inner scope and have a definition. Shadow
3123                                  * existing definition in outer scope */
3124                                 entity = NULL;
3125                         } else if (entity->enume.complete && token.type == '{') {
3126                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3127                                                 symbol, &entity->base.source_position);
3128                         }
3129                 }
3130         } else if (token.type != '{') {
3131                 parse_error_expected("while parsing enum type specifier",
3132                                      T_IDENTIFIER, '{', NULL);
3133                 return NULL;
3134         } else {
3135                 entity  = NULL;
3136                 symbol  = NULL;
3137         }
3138
3139         if (entity == NULL) {
3140                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3141                 entity->base.namespc         = NAMESPACE_ENUM;
3142                 entity->base.source_position = token.source_position;
3143                 entity->base.symbol          = symbol;
3144                 entity->base.parent_scope    = current_scope;
3145         }
3146
3147         type_t *const type = allocate_type_zero(TYPE_ENUM);
3148         type->enumt.enume  = &entity->enume;
3149         type->enumt.akind  = ATOMIC_TYPE_INT;
3150
3151         if (token.type == '{') {
3152                 if (symbol != NULL) {
3153                         environment_push(entity);
3154                 }
3155                 append_entity(current_scope, entity);
3156                 entity->enume.complete = true;
3157
3158                 parse_enum_entries(type);
3159                 parse_attributes(&attributes);
3160
3161                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
3162                 if (symbol == NULL) {
3163                         assert(anonymous_entity == NULL);
3164                         anonymous_entity = entity;
3165                 }
3166         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3167                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3168                        symbol);
3169         }
3170
3171         return type;
3172 }
3173
3174 /**
3175  * if a symbol is a typedef to another type, return true
3176  */
3177 static bool is_typedef_symbol(symbol_t *symbol)
3178 {
3179         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3180         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3181 }
3182
3183 static type_t *parse_typeof(void)
3184 {
3185         eat(T___typeof__);
3186
3187         type_t *type;
3188
3189         expect('(', end_error);
3190         add_anchor_token(')');
3191
3192         expression_t *expression  = NULL;
3193
3194         bool old_type_prop     = in_type_prop;
3195         bool old_gcc_extension = in_gcc_extension;
3196         in_type_prop           = true;
3197
3198         while (token.type == T___extension__) {
3199                 /* This can be a prefix to a typename or an expression. */
3200                 next_token();
3201                 in_gcc_extension = true;
3202         }
3203         switch (token.type) {
3204         case T_IDENTIFIER:
3205                 if (is_typedef_symbol(token.v.symbol)) {
3206                         type = parse_typename();
3207                 } else {
3208                         expression = parse_expression();
3209                         type       = revert_automatic_type_conversion(expression);
3210                 }
3211                 break;
3212
3213         TYPENAME_START
3214                 type = parse_typename();
3215                 break;
3216
3217         default:
3218                 expression = parse_expression();
3219                 type       = expression->base.type;
3220                 break;
3221         }
3222         in_type_prop     = old_type_prop;
3223         in_gcc_extension = old_gcc_extension;
3224
3225         rem_anchor_token(')');
3226         expect(')', end_error);
3227
3228         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3229         typeof_type->typeoft.expression  = expression;
3230         typeof_type->typeoft.typeof_type = type;
3231
3232         return typeof_type;
3233 end_error:
3234         return NULL;
3235 }
3236
3237 typedef enum specifiers_t {
3238         SPECIFIER_SIGNED    = 1 << 0,
3239         SPECIFIER_UNSIGNED  = 1 << 1,
3240         SPECIFIER_LONG      = 1 << 2,
3241         SPECIFIER_INT       = 1 << 3,
3242         SPECIFIER_DOUBLE    = 1 << 4,
3243         SPECIFIER_CHAR      = 1 << 5,
3244         SPECIFIER_WCHAR_T   = 1 << 6,
3245         SPECIFIER_SHORT     = 1 << 7,
3246         SPECIFIER_LONG_LONG = 1 << 8,
3247         SPECIFIER_FLOAT     = 1 << 9,
3248         SPECIFIER_BOOL      = 1 << 10,
3249         SPECIFIER_VOID      = 1 << 11,
3250         SPECIFIER_INT8      = 1 << 12,
3251         SPECIFIER_INT16     = 1 << 13,
3252         SPECIFIER_INT32     = 1 << 14,
3253         SPECIFIER_INT64     = 1 << 15,
3254         SPECIFIER_INT128    = 1 << 16,
3255         SPECIFIER_COMPLEX   = 1 << 17,
3256         SPECIFIER_IMAGINARY = 1 << 18,
3257 } specifiers_t;
3258
3259 static type_t *create_builtin_type(symbol_t *const symbol,
3260                                    type_t *const real_type)
3261 {
3262         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3263         type->builtin.symbol    = symbol;
3264         type->builtin.real_type = real_type;
3265         return identify_new_type(type);
3266 }
3267
3268 static type_t *get_typedef_type(symbol_t *symbol)
3269 {
3270         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3271         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3272                 return NULL;
3273
3274         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3275         type->typedeft.typedefe = &entity->typedefe;
3276
3277         return type;
3278 }
3279
3280 /**
3281  * check for the allowed MS alignment values.
3282  */
3283 static bool check_alignment_value(long long intvalue)
3284 {
3285         if (intvalue < 1 || intvalue > 8192) {
3286                 errorf(HERE, "illegal alignment value");
3287                 return false;
3288         }
3289         unsigned v = (unsigned)intvalue;
3290         for (unsigned i = 1; i <= 8192; i += i) {
3291                 if (i == v)
3292                         return true;
3293         }
3294         errorf(HERE, "alignment must be power of two");
3295         return false;
3296 }
3297
3298 #define DET_MOD(name, tag) do { \
3299         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3300         *modifiers |= tag; \
3301 } while (0)
3302
3303 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3304 {
3305         decl_modifiers_t *modifiers = &specifiers->modifiers;
3306
3307         while (true) {
3308                 if (token.type == T_restrict) {
3309                         next_token();
3310                         DET_MOD(restrict, DM_RESTRICT);
3311                         goto end_loop;
3312                 } else if (token.type != T_IDENTIFIER)
3313                         break;
3314                 symbol_t *symbol = token.v.symbol;
3315                 if (symbol == sym_align) {
3316                         next_token();
3317                         expect('(', end_error);
3318                         if (token.type != T_INTEGER)
3319                                 goto end_error;
3320                         if (check_alignment_value(token.v.intvalue)) {
3321                                 if (specifiers->alignment != 0 && warning.other)
3322                                         warningf(HERE, "align used more than once");
3323                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3324                         }
3325                         next_token();
3326                         expect(')', end_error);
3327                 } else if (symbol == sym_allocate) {
3328                         next_token();
3329                         expect('(', end_error);
3330                         if (token.type != T_IDENTIFIER)
3331                                 goto end_error;
3332                         (void)token.v.symbol;
3333                         expect(')', end_error);
3334                 } else if (symbol == sym_dllimport) {
3335                         next_token();
3336                         DET_MOD(dllimport, DM_DLLIMPORT);
3337                 } else if (symbol == sym_dllexport) {
3338                         next_token();
3339                         DET_MOD(dllexport, DM_DLLEXPORT);
3340                 } else if (symbol == sym_thread) {
3341                         next_token();
3342                         DET_MOD(thread, DM_THREAD);
3343                 } else if (symbol == sym_naked) {
3344                         next_token();
3345                         DET_MOD(naked, DM_NAKED);
3346                 } else if (symbol == sym_noinline) {
3347                         next_token();
3348                         DET_MOD(noinline, DM_NOINLINE);
3349                 } else if (symbol == sym_returns_twice) {
3350                         next_token();
3351                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3352                 } else if (symbol == sym_noreturn) {
3353                         next_token();
3354                         DET_MOD(noreturn, DM_NORETURN);
3355                 } else if (symbol == sym_nothrow) {
3356                         next_token();
3357                         DET_MOD(nothrow, DM_NOTHROW);
3358                 } else if (symbol == sym_novtable) {
3359                         next_token();
3360                         DET_MOD(novtable, DM_NOVTABLE);
3361                 } else if (symbol == sym_property) {
3362                         next_token();
3363                         expect('(', end_error);
3364                         for (;;) {
3365                                 bool is_get = false;
3366                                 if (token.type != T_IDENTIFIER)
3367                                         goto end_error;
3368                                 if (token.v.symbol == sym_get) {
3369                                         is_get = true;
3370                                 } else if (token.v.symbol == sym_put) {
3371                                 } else {
3372                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3373                                         goto end_error;
3374                                 }
3375                                 next_token();
3376                                 expect('=', end_error);
3377                                 if (token.type != T_IDENTIFIER)
3378                                         goto end_error;
3379                                 if (is_get) {
3380                                         if (specifiers->get_property_sym != NULL) {
3381                                                 errorf(HERE, "get property name already specified");
3382                                         } else {
3383                                                 specifiers->get_property_sym = token.v.symbol;
3384                                         }
3385                                 } else {
3386                                         if (specifiers->put_property_sym != NULL) {
3387                                                 errorf(HERE, "put property name already specified");
3388                                         } else {
3389                                                 specifiers->put_property_sym = token.v.symbol;
3390                                         }
3391                                 }
3392                                 next_token();
3393                                 if (token.type == ',') {
3394                                         next_token();
3395                                         continue;
3396                                 }
3397                                 break;
3398                         }
3399                         expect(')', end_error);
3400                 } else if (symbol == sym_selectany) {
3401                         next_token();
3402                         DET_MOD(selectany, DM_SELECTANY);
3403                 } else if (symbol == sym_uuid) {
3404                         next_token();
3405                         expect('(', end_error);
3406                         if (token.type != T_STRING_LITERAL)
3407                                 goto end_error;
3408                         next_token();
3409                         expect(')', end_error);
3410                 } else if (symbol == sym_deprecated) {
3411                         next_token();
3412                         if (specifiers->deprecated != 0 && warning.other)
3413                                 warningf(HERE, "deprecated used more than once");
3414                         specifiers->deprecated = true;
3415                         if (token.type == '(') {
3416                                 next_token();
3417                                 if (token.type == T_STRING_LITERAL) {
3418                                         specifiers->deprecated_string = token.v.string.begin;
3419                                         next_token();
3420                                 } else {
3421                                         errorf(HERE, "string literal expected");
3422                                 }
3423                                 expect(')', end_error);
3424                         }
3425                 } else if (symbol == sym_noalias) {
3426                         next_token();
3427                         DET_MOD(noalias, DM_NOALIAS);
3428                 } else {
3429                         if (warning.other)
3430                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3431                         next_token();
3432                         if (token.type == '(')
3433                                 skip_until(')');
3434                 }
3435 end_loop:
3436                 if (token.type == ',')
3437                         next_token();
3438         }
3439 end_error:
3440         return;
3441 }
3442
3443 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3444 {
3445         entity_t *entity             = allocate_entity_zero(kind);
3446         entity->base.source_position = *HERE;
3447         entity->base.symbol          = symbol;
3448         if (is_declaration(entity)) {
3449                 entity->declaration.type     = type_error_type;
3450                 entity->declaration.implicit = true;
3451         } else if (kind == ENTITY_TYPEDEF) {
3452                 entity->typedefe.type    = type_error_type;
3453                 entity->typedefe.builtin = true;
3454         }
3455         if (kind != ENTITY_COMPOUND_MEMBER)
3456                 record_entity(entity, false);
3457         return entity;
3458 }
3459
3460 static variable_t *parse_microsoft_based(void)
3461 {
3462         if (token.type != T_IDENTIFIER) {
3463                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3464                 return NULL;
3465         }
3466         symbol_t *symbol = token.v.symbol;
3467         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3468
3469         variable_t *variable;
3470         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3471                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3472                 variable = &create_error_entity(symbol, ENTITY_VARIABLE)->variable;
3473         } else {
3474                 variable = &entity->variable;
3475
3476                 type_t *const type = variable->base.type;
3477                 if (is_type_valid(type)) {
3478                         if (! is_type_pointer(skip_typeref(type))) {
3479                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3480                         }
3481                         if (variable->base.base.parent_scope != file_scope) {
3482                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3483                         }
3484                 }
3485         }
3486         next_token();
3487         return variable;
3488 }
3489
3490 /**
3491  * Finish the construction of a struct type by calculating
3492  * its size, offsets, alignment.
3493  */
3494 static void finish_struct_type(compound_type_t *type)
3495 {
3496         assert(type->compound != NULL);
3497
3498         compound_t *compound = type->compound;
3499         if (!compound->complete)
3500                 return;
3501
3502         il_size_t      size           = 0;
3503         il_size_t      offset;
3504         il_alignment_t alignment      = 1;
3505         bool           need_pad       = false;
3506
3507         entity_t *entry = compound->members.entities;
3508         for (; entry != NULL; entry = entry->base.next) {
3509                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3510                         continue;
3511
3512                 type_t *m_type = skip_typeref(entry->declaration.type);
3513                 if (! is_type_valid(m_type)) {
3514                         /* simply ignore errors here */
3515                         continue;
3516                 }
3517                 il_alignment_t m_alignment = m_type->base.alignment;
3518                 if (m_alignment > alignment)
3519                         alignment = m_alignment;
3520
3521                 offset = (size + m_alignment - 1) & -m_alignment;
3522
3523                 if (offset > size)
3524                         need_pad = true;
3525                 entry->compound_member.offset = offset;
3526                 size = offset + m_type->base.size;
3527         }
3528         if (type->base.alignment != 0) {
3529                 alignment = type->base.alignment;
3530         }
3531
3532         offset = (size + alignment - 1) & -alignment;
3533         if (offset > size)
3534                 need_pad = true;
3535
3536         if (need_pad) {
3537                 if (warning.padded) {
3538                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3539                 }
3540         } else {
3541                 if (compound->modifiers & DM_PACKED && warning.packed) {
3542                         warningf(&compound->base.source_position,
3543                                         "superfluous packed attribute on '%T'", type);
3544                 }
3545         }
3546
3547         type->base.size      = offset;
3548         type->base.alignment = alignment;
3549 }
3550
3551 /**
3552  * Finish the construction of an union type by calculating
3553  * its size and alignment.
3554  */
3555 static void finish_union_type(compound_type_t *type)
3556 {
3557         assert(type->compound != NULL);
3558
3559         compound_t *compound = type->compound;
3560         if (! compound->complete)
3561                 return;
3562
3563         il_size_t      size      = 0;
3564         il_alignment_t alignment = 1;
3565
3566         entity_t *entry = compound->members.entities;
3567         for (; entry != NULL; entry = entry->base.next) {
3568                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3569                         continue;
3570
3571                 type_t *m_type = skip_typeref(entry->declaration.type);
3572                 if (! is_type_valid(m_type))
3573                         continue;
3574
3575                 entry->compound_member.offset = 0;
3576                 if (m_type->base.size > size)
3577                         size = m_type->base.size;
3578                 if (m_type->base.alignment > alignment)
3579                         alignment = m_type->base.alignment;
3580         }
3581         if (type->base.alignment != 0) {
3582                 alignment = type->base.alignment;
3583         }
3584         size = (size + alignment - 1) & -alignment;
3585         type->base.size      = size;
3586         type->base.alignment = alignment;
3587 }
3588
3589 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3590                                      type_t *orig_type)
3591 {
3592         type_t *type = skip_typeref(orig_type);
3593
3594         /* at least: byte, word, pointer, list of machine modes
3595          * __XXX___ is interpreted as XXX */
3596
3597         /* This isn't really correct, the backend should provide a list of machine
3598          * specific modes (according to gcc philosophy that is...) */
3599         const char         *symbol_str = attribute->u.symbol->string;
3600         bool                sign       = is_type_signed(type);
3601         atomic_type_kind_t  akind;
3602         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3603             strcmp_underscore("byte", symbol_str) == 0) {
3604                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3605         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3606                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3607         } else if (strcmp_underscore("SI",      symbol_str) == 0
3608                 || strcmp_underscore("word",    symbol_str) == 0
3609                 || strcmp_underscore("pointer", symbol_str) == 0) {
3610                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3611         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3612                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3613         } else {
3614                 if (warning.other)
3615                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3616                 return orig_type;
3617         }
3618
3619         if (type->kind == TYPE_ATOMIC) {
3620                 type_t *copy       = duplicate_type(type);
3621                 copy->atomic.akind = akind;
3622                 return identify_new_type(copy);
3623         } else if (type->kind == TYPE_ENUM) {
3624                 type_t *copy      = duplicate_type(type);
3625                 copy->enumt.akind = akind;
3626                 return identify_new_type(copy);
3627         } else if (is_type_pointer(type)) {
3628                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3629                 return type;
3630         }
3631
3632         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3633         return orig_type;
3634 }
3635
3636 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3637                                       type_t *type)
3638 {
3639         const gnu_attribute_t *attribute = attributes;
3640         for ( ; attribute != NULL; attribute = attribute->next) {
3641                 if (attribute->invalid)
3642                         continue;
3643
3644                 if (attribute->kind == GNU_AK_MODE) {
3645                         type = handle_attribute_mode(attribute, type);
3646                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3647                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3648                                                target machine */
3649                         if (attribute->has_arguments)
3650                                 alignment = attribute->u.argument;
3651
3652                         type_t *copy         = duplicate_type(type);
3653                         copy->base.alignment = attribute->u.argument;
3654                         type                 = identify_new_type(copy);
3655                 }
3656         }
3657
3658         return type;
3659 }
3660
3661 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3662 {
3663         type_t            *type              = NULL;
3664         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3665         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3666         unsigned           type_specifiers   = 0;
3667         bool               newtype           = false;
3668         bool               saw_error         = false;
3669         bool               old_gcc_extension = in_gcc_extension;
3670
3671         specifiers->source_position = token.source_position;
3672
3673         while (true) {
3674                 specifiers->modifiers
3675                         |= parse_attributes(&specifiers->gnu_attributes);
3676
3677                 switch (token.type) {
3678                 /* storage class */
3679 #define MATCH_STORAGE_CLASS(token, class)                                  \
3680                 case token:                                                        \
3681                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3682                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3683                         }                                                              \
3684                         specifiers->storage_class = class;                             \
3685                         if (specifiers->thread_local)                                  \
3686                                 goto check_thread_storage_class;                           \
3687                         next_token();                                                  \
3688                         break;
3689
3690                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3691                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3692                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3693                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3694                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3695
3696                 case T__declspec:
3697                         next_token();
3698                         expect('(', end_error);
3699                         add_anchor_token(')');
3700                         parse_microsoft_extended_decl_modifier(specifiers);
3701                         rem_anchor_token(')');
3702                         expect(')', end_error);
3703                         break;
3704
3705                 case T___thread:
3706                         if (specifiers->thread_local) {
3707                                 errorf(HERE, "duplicate '__thread'");
3708                         } else {
3709                                 specifiers->thread_local = true;
3710 check_thread_storage_class:
3711                                 switch (specifiers->storage_class) {
3712                                         case STORAGE_CLASS_EXTERN:
3713                                         case STORAGE_CLASS_NONE:
3714                                         case STORAGE_CLASS_STATIC:
3715                                                 break;
3716
3717                                                 char const* wrong;
3718                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3719                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3720                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3721 wrong_thread_stoarge_class:
3722                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3723                                                 break;
3724                                 }
3725                         }
3726                         next_token();
3727                         break;
3728
3729                 /* type qualifiers */
3730 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3731                 case token:                                                     \
3732                         qualifiers |= qualifier;                                    \
3733                         next_token();                                               \
3734                         break
3735
3736                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3737                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3738                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3739                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3740                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3741                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3742                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3743                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3744
3745                 case T___extension__:
3746                         next_token();
3747                         in_gcc_extension = true;
3748                         break;
3749
3750                 /* type specifiers */
3751 #define MATCH_SPECIFIER(token, specifier, name)                         \
3752                 case token:                                                     \
3753                         if (type_specifiers & specifier) {                           \
3754                                 errorf(HERE, "multiple " name " type specifiers given"); \
3755                         } else {                                                    \
3756                                 type_specifiers |= specifier;                           \
3757                         }                                                           \
3758                         next_token();                                               \
3759                         break
3760
3761                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3762                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3763                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3764                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3765                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3766                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3767                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3768                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3769                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3770                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3771                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3772                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3773                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3774                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3775                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3776                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3777                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3778                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3779
3780                 case T__forceinline:
3781                         /* only in microsoft mode */
3782                         specifiers->modifiers |= DM_FORCEINLINE;
3783                         /* FALLTHROUGH */
3784
3785                 case T_inline:
3786                         next_token();
3787                         specifiers->is_inline = true;
3788                         break;
3789
3790                 case T_long:
3791                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3792                                 errorf(HERE, "multiple type specifiers given");
3793                         } else if (type_specifiers & SPECIFIER_LONG) {
3794                                 type_specifiers |= SPECIFIER_LONG_LONG;
3795                         } else {
3796                                 type_specifiers |= SPECIFIER_LONG;
3797                         }
3798                         next_token();
3799                         break;
3800
3801                 case T_struct: {
3802                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3803
3804                         type->compound.compound = parse_compound_type_specifier(true);
3805                         finish_struct_type(&type->compound);
3806                         break;
3807                 }
3808                 case T_union: {
3809                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3810                         type->compound.compound = parse_compound_type_specifier(false);
3811                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3812                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3813                         finish_union_type(&type->compound);
3814                         break;
3815                 }
3816                 case T_enum:
3817                         type = parse_enum_specifier();
3818                         break;
3819                 case T___typeof__:
3820                         type = parse_typeof();
3821                         break;
3822                 case T___builtin_va_list:
3823                         type = duplicate_type(type_valist);
3824                         next_token();
3825                         break;
3826
3827                 case T_IDENTIFIER: {
3828                         /* only parse identifier if we haven't found a type yet */
3829                         if (type != NULL || type_specifiers != 0) {
3830                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3831                                  * declaration, so it doesn't generate errors about expecting '(' or
3832                                  * '{' later on. */
3833                                 switch (look_ahead(1)->type) {
3834                                         STORAGE_CLASSES
3835                                         TYPE_SPECIFIERS
3836                                         case T_const:
3837                                         case T_restrict:
3838                                         case T_volatile:
3839                                         case T_inline:
3840                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3841                                         case T_IDENTIFIER:
3842                                         case '&':
3843                                         case '*':
3844                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3845                                                 next_token();
3846                                                 continue;
3847
3848                                         default:
3849                                                 goto finish_specifiers;
3850                                 }
3851                         }
3852
3853                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3854                         if (typedef_type == NULL) {
3855                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3856                                  * declaration, so it doesn't generate 'implicit int' followed by more
3857                                  * errors later on. */
3858                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3859                                 switch (la1_type) {
3860                                         DECLARATION_START
3861                                         case T_IDENTIFIER:
3862                                         case '&':
3863                                         case '*': {
3864                                                 errorf(HERE, "%K does not name a type", &token);
3865
3866                                                 entity_t *entity =
3867                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3868
3869                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3870                                                 type->typedeft.typedefe = &entity->typedefe;
3871
3872                                                 next_token();
3873                                                 saw_error = true;
3874                                                 if (la1_type == '&' || la1_type == '*')
3875                                                         goto finish_specifiers;
3876                                                 continue;
3877                                         }
3878
3879                                         default:
3880                                                 goto finish_specifiers;
3881                                 }
3882                         }
3883
3884                         next_token();
3885                         type = typedef_type;
3886                         break;
3887                 }
3888
3889                 /* function specifier */
3890                 default:
3891                         goto finish_specifiers;
3892                 }
3893         }
3894
3895 finish_specifiers:
3896         specifiers->modifiers
3897                 |= parse_attributes(&specifiers->gnu_attributes);
3898
3899         in_gcc_extension = old_gcc_extension;
3900
3901         if (type == NULL || (saw_error && type_specifiers != 0)) {
3902                 atomic_type_kind_t atomic_type;
3903
3904                 /* match valid basic types */
3905                 switch (type_specifiers) {
3906                 case SPECIFIER_VOID:
3907                         atomic_type = ATOMIC_TYPE_VOID;
3908                         break;
3909                 case SPECIFIER_WCHAR_T:
3910                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3911                         break;
3912                 case SPECIFIER_CHAR:
3913                         atomic_type = ATOMIC_TYPE_CHAR;
3914                         break;
3915                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3916                         atomic_type = ATOMIC_TYPE_SCHAR;
3917                         break;
3918                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3919                         atomic_type = ATOMIC_TYPE_UCHAR;
3920                         break;
3921                 case SPECIFIER_SHORT:
3922                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3923                 case SPECIFIER_SHORT | SPECIFIER_INT:
3924                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3925                         atomic_type = ATOMIC_TYPE_SHORT;
3926                         break;
3927                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3928                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3929                         atomic_type = ATOMIC_TYPE_USHORT;
3930                         break;
3931                 case SPECIFIER_INT:
3932                 case SPECIFIER_SIGNED:
3933                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3934                         atomic_type = ATOMIC_TYPE_INT;
3935                         break;
3936                 case SPECIFIER_UNSIGNED:
3937                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3938                         atomic_type = ATOMIC_TYPE_UINT;
3939                         break;
3940                 case SPECIFIER_LONG:
3941                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3942                 case SPECIFIER_LONG | SPECIFIER_INT:
3943                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3944                         atomic_type = ATOMIC_TYPE_LONG;
3945                         break;
3946                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3947                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3948                         atomic_type = ATOMIC_TYPE_ULONG;
3949                         break;
3950
3951                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3952                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3953                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3954                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3955                         | SPECIFIER_INT:
3956                         atomic_type = ATOMIC_TYPE_LONGLONG;
3957                         goto warn_about_long_long;
3958
3959                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3960                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3961                         | SPECIFIER_INT:
3962                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3963 warn_about_long_long:
3964                         if (warning.long_long) {
3965                                 warningf(&specifiers->source_position,
3966                                          "ISO C90 does not support 'long long'");
3967                         }
3968                         break;
3969
3970                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3971                         atomic_type = unsigned_int8_type_kind;
3972                         break;
3973
3974                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3975                         atomic_type = unsigned_int16_type_kind;
3976                         break;
3977
3978                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3979                         atomic_type = unsigned_int32_type_kind;
3980                         break;
3981
3982                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3983                         atomic_type = unsigned_int64_type_kind;
3984                         break;
3985
3986                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3987                         atomic_type = unsigned_int128_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT8:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3992                         atomic_type = int8_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT16:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3997                         atomic_type = int16_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_INT32:
4001                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
4002                         atomic_type = int32_type_kind;
4003                         break;
4004
4005                 case SPECIFIER_INT64:
4006                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
4007                         atomic_type = int64_type_kind;
4008                         break;
4009
4010                 case SPECIFIER_INT128:
4011                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
4012                         atomic_type = int128_type_kind;
4013                         break;
4014
4015                 case SPECIFIER_FLOAT:
4016                         atomic_type = ATOMIC_TYPE_FLOAT;
4017                         break;
4018                 case SPECIFIER_DOUBLE:
4019                         atomic_type = ATOMIC_TYPE_DOUBLE;
4020                         break;
4021                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4022                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4023                         break;
4024                 case SPECIFIER_BOOL:
4025                         atomic_type = ATOMIC_TYPE_BOOL;
4026                         break;
4027                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4028                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4029                         atomic_type = ATOMIC_TYPE_FLOAT;
4030                         break;
4031                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4032                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4033                         atomic_type = ATOMIC_TYPE_DOUBLE;
4034                         break;
4035                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4036                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4037                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4038                         break;
4039                 default:
4040                         /* invalid specifier combination, give an error message */
4041                         if (type_specifiers == 0) {
4042                                 if (saw_error)
4043                                         goto end_error;
4044
4045                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4046                                 if (!(c_mode & _CXX) && !strict_mode) {
4047                                         if (warning.implicit_int) {
4048                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4049                                         }
4050                                         atomic_type = ATOMIC_TYPE_INT;
4051                                         break;
4052                                 } else {
4053                                         errorf(HERE, "no type specifiers given in declaration");
4054                                 }
4055                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4056                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4057                                 errorf(HERE, "signed and unsigned specifiers given");
4058                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4059                                 errorf(HERE, "only integer types can be signed or unsigned");
4060                         } else {
4061                                 errorf(HERE, "multiple datatypes in declaration");
4062                         }
4063                         goto end_error;
4064                 }
4065
4066                 if (type_specifiers & SPECIFIER_COMPLEX) {
4067                         type                = allocate_type_zero(TYPE_COMPLEX);
4068                         type->complex.akind = atomic_type;
4069                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4070                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4071                         type->imaginary.akind = atomic_type;
4072                 } else {
4073                         type                 = allocate_type_zero(TYPE_ATOMIC);
4074                         type->atomic.akind   = atomic_type;
4075                 }
4076                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4077                 unsigned const size  = get_atomic_type_size(atomic_type);
4078                 type->base.size      =
4079                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4080                 newtype = true;
4081         } else if (type_specifiers != 0) {
4082                 errorf(HERE, "multiple datatypes in declaration");
4083         }
4084
4085         /* FIXME: check type qualifiers here */
4086
4087         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4088                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4089         type->base.qualifiers = qualifiers;
4090         type->base.modifiers  = modifiers;
4091
4092         if (newtype) {
4093                 type = identify_new_type(type);
4094         } else {
4095                 type = typehash_insert(type);
4096         }
4097
4098         type = handle_type_attributes(specifiers->gnu_attributes, type);
4099         specifiers->type = type;
4100         return;
4101
4102 end_error:
4103         specifiers->type = type_error_type;
4104         return;
4105 }
4106
4107 static type_qualifiers_t parse_type_qualifiers(void)
4108 {
4109         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4110
4111         while (true) {
4112                 switch (token.type) {
4113                 /* type qualifiers */
4114                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4115                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4116                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4117                 /* microsoft extended type modifiers */
4118                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4119                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4120                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4121                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4122                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4123
4124                 default:
4125                         return qualifiers;
4126                 }
4127         }
4128 }
4129
4130 /**
4131  * Parses an K&R identifier list
4132  */
4133 static void parse_identifier_list(scope_t *scope)
4134 {
4135         do {
4136                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4137                 entity->base.source_position = token.source_position;
4138                 entity->base.namespc         = NAMESPACE_NORMAL;
4139                 entity->base.symbol          = token.v.symbol;
4140                 /* a K&R parameter has no type, yet */
4141                 next_token();
4142
4143                 if (scope != NULL)
4144                         append_entity(scope, entity);
4145
4146                 if (token.type != ',') {
4147                         break;
4148                 }
4149                 next_token();
4150         } while (token.type == T_IDENTIFIER);
4151 }
4152
4153 static entity_t *parse_parameter(void)
4154 {
4155         declaration_specifiers_t specifiers;
4156         memset(&specifiers, 0, sizeof(specifiers));
4157
4158         parse_declaration_specifiers(&specifiers);
4159
4160         entity_t *entity = parse_declarator(&specifiers,
4161                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4162         anonymous_entity = NULL;
4163         return entity;
4164 }
4165
4166 static void semantic_parameter_incomplete(const entity_t *entity)
4167 {
4168         assert(entity->kind == ENTITY_PARAMETER);
4169
4170         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4171          *             list in a function declarator that is part of a
4172          *             definition of that function shall not have
4173          *             incomplete type. */
4174         type_t *type = skip_typeref(entity->declaration.type);
4175         if (is_type_incomplete(type)) {
4176                 errorf(&entity->base.source_position,
4177                                 "parameter '%#T' has incomplete type",
4178                                 entity->declaration.type, entity->base.symbol);
4179         }
4180 }
4181
4182 static bool has_parameters(void)
4183 {
4184         /* func(void) is not a parameter */
4185         if (token.type == T_IDENTIFIER) {
4186                 entity_t const *const entity = get_entity(token.v.symbol, NAMESPACE_NORMAL);
4187                 if (entity->kind != ENTITY_TYPEDEF)
4188                         return true;
4189                 if (skip_typeref(entity->typedefe.type) != type_void)
4190                         return true;
4191         } else if (token.type != T_void) {
4192                 return true;
4193         }
4194         if (look_ahead(1)->type != ')')
4195                 return true;
4196         next_token();
4197         return false;
4198 }
4199
4200 /**
4201  * Parses function type parameters (and optionally creates variable_t entities
4202  * for them in a scope)
4203  */
4204 static void parse_parameters(function_type_t *type, scope_t *scope)
4205 {
4206         eat('(');
4207         add_anchor_token(')');
4208         int saved_comma_state = save_and_reset_anchor_state(',');
4209
4210         if (token.type == T_IDENTIFIER &&
4211             !is_typedef_symbol(token.v.symbol)) {
4212                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4213                 if (la1_type == ',' || la1_type == ')') {
4214                         type->kr_style_parameters    = true;
4215                         type->unspecified_parameters = true;
4216                         parse_identifier_list(scope);
4217                         goto parameters_finished;
4218                 }
4219         }
4220
4221         if (token.type == ')') {
4222                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4223                 if (!(c_mode & _CXX))
4224                         type->unspecified_parameters = true;
4225                 goto parameters_finished;
4226         }
4227
4228         if (has_parameters()) {
4229                 function_parameter_t **anchor = &type->parameters;
4230                 for (;;) {
4231                         switch (token.type) {
4232                         case T_DOTDOTDOT:
4233                                 next_token();
4234                                 type->variadic = true;
4235                                 goto parameters_finished;
4236
4237                         case T_IDENTIFIER:
4238                         case T___extension__:
4239                         DECLARATION_START
4240                         {
4241                                 entity_t *entity = parse_parameter();
4242                                 if (entity->kind == ENTITY_TYPEDEF) {
4243                                         errorf(&entity->base.source_position,
4244                                                         "typedef not allowed as function parameter");
4245                                         break;
4246                                 }
4247                                 assert(is_declaration(entity));
4248
4249                                 semantic_parameter_incomplete(entity);
4250
4251                                 function_parameter_t *const parameter =
4252                                         allocate_parameter(entity->declaration.type);
4253
4254                                 if (scope != NULL) {
4255                                         append_entity(scope, entity);
4256                                 }
4257
4258                                 *anchor = parameter;
4259                                 anchor  = &parameter->next;
4260                                 break;
4261                         }
4262
4263                         default:
4264                                 goto parameters_finished;
4265                         }
4266                         if (token.type != ',') {
4267                                 goto parameters_finished;
4268                         }
4269                         next_token();
4270                 }
4271         }
4272
4273
4274 parameters_finished:
4275         rem_anchor_token(')');
4276         expect(')', end_error);
4277
4278 end_error:
4279         restore_anchor_state(',', saved_comma_state);
4280 }
4281
4282 typedef enum construct_type_kind_t {
4283         CONSTRUCT_INVALID,
4284         CONSTRUCT_POINTER,
4285         CONSTRUCT_REFERENCE,
4286         CONSTRUCT_FUNCTION,
4287         CONSTRUCT_ARRAY
4288 } construct_type_kind_t;
4289
4290 typedef union construct_type_t construct_type_t;
4291
4292 typedef struct construct_type_base_t {
4293         construct_type_kind_t  kind;
4294         construct_type_t      *next;
4295 } construct_type_base_t;
4296
4297 typedef struct parsed_pointer_t {
4298         construct_type_base_t  base;
4299         type_qualifiers_t      type_qualifiers;
4300         variable_t             *base_variable;  /**< MS __based extension. */
4301 } parsed_pointer_t;
4302
4303 typedef struct parsed_reference_t {
4304         construct_type_base_t base;
4305 } parsed_reference_t;
4306
4307 typedef struct construct_function_type_t {
4308         construct_type_base_t  base;
4309         type_t                *function_type;
4310 } construct_function_type_t;
4311
4312 typedef struct parsed_array_t {
4313         construct_type_base_t  base;
4314         type_qualifiers_t      type_qualifiers;
4315         bool                   is_static;
4316         bool                   is_variable;
4317         expression_t          *size;
4318 } parsed_array_t;
4319
4320 union construct_type_t {
4321         construct_type_kind_t     kind;
4322         construct_type_base_t     base;
4323         parsed_pointer_t          pointer;
4324         parsed_reference_t        reference;
4325         construct_function_type_t function;
4326         parsed_array_t            array;
4327 };
4328
4329 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4330 {
4331         eat('*');
4332
4333         construct_type_t *cons    = obstack_alloc(&temp_obst, sizeof(cons->pointer));
4334         parsed_pointer_t *pointer = &cons->pointer;
4335         memset(pointer, 0, sizeof(*pointer));
4336         cons->kind               = CONSTRUCT_POINTER;
4337         pointer->type_qualifiers = parse_type_qualifiers();
4338         pointer->base_variable   = base_variable;
4339
4340         return cons;
4341 }
4342
4343 static construct_type_t *parse_reference_declarator(void)
4344 {
4345         eat('&');
4346
4347         construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
4348         parsed_reference_t *reference = &cons->reference;
4349         memset(reference, 0, sizeof(*reference));
4350         cons->kind = CONSTRUCT_REFERENCE;
4351
4352         return cons;
4353 }
4354
4355 static construct_type_t *parse_array_declarator(void)
4356 {
4357         eat('[');
4358         add_anchor_token(']');
4359
4360         construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
4361         parsed_array_t   *array = &cons->array;
4362         memset(array, 0, sizeof(*array));
4363         cons->kind = CONSTRUCT_ARRAY;
4364
4365         if (token.type == T_static) {
4366                 array->is_static = true;
4367                 next_token();
4368         }
4369
4370         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4371         if (type_qualifiers != 0) {
4372                 if (token.type == T_static) {
4373                         array->is_static = true;
4374                         next_token();
4375                 }
4376         }
4377         array->type_qualifiers = type_qualifiers;
4378
4379         if (token.type == '*' && look_ahead(1)->type == ']') {
4380                 array->is_variable = true;
4381                 next_token();
4382         } else if (token.type != ']') {
4383                 expression_t *const size = parse_assignment_expression();
4384                 array->size = size;
4385                 mark_vars_read(size, NULL);
4386         }
4387
4388         rem_anchor_token(']');
4389         expect(']', end_error);
4390
4391 end_error:
4392         return cons;
4393 }
4394
4395 static construct_type_t *parse_function_declarator(scope_t *scope,
4396                                                    decl_modifiers_t modifiers)
4397 {
4398         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4399         function_type_t *ftype = &type->function;
4400
4401         ftype->linkage = current_linkage;
4402
4403         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4404                 case DM_NONE:     break;
4405                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4406                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4407                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4408                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4409
4410                 default:
4411                         errorf(HERE, "multiple calling conventions in declaration");
4412                         break;
4413         }
4414
4415         parse_parameters(ftype, scope);
4416
4417         construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
4418         construct_function_type_t *function = &cons->function;
4419         memset(function, 0, sizeof(*function));
4420         cons->kind              = CONSTRUCT_FUNCTION;
4421         function->function_type = type;
4422
4423         return cons;
4424 }
4425
4426 typedef struct parse_declarator_env_t {
4427         decl_modifiers_t   modifiers;
4428         symbol_t          *symbol;
4429         source_position_t  source_position;
4430         scope_t            parameters;
4431 } parse_declarator_env_t;
4432
4433 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4434                 bool may_be_abstract)
4435 {
4436         /* construct a single linked list of construct_type_t's which describe
4437          * how to construct the final declarator type */
4438         construct_type_t  *first      = NULL;
4439         construct_type_t **anchor     = &first;
4440         gnu_attribute_t   *attributes = NULL;
4441
4442         decl_modifiers_t modifiers = parse_attributes(&attributes);
4443
4444         for (;;) {
4445                 construct_type_t *type;
4446                 variable_t       *based = NULL; /* MS __based extension */
4447                 switch (token.type) {
4448                         case '&':
4449                                 if (!(c_mode & _CXX))
4450                                         errorf(HERE, "references are only available for C++");
4451                                 type = parse_reference_declarator();
4452                                 break;
4453
4454                         case T__based: {
4455                                 source_position_t const pos = *HERE;
4456                                 next_token();
4457                                 expect('(', end_error);
4458                                 add_anchor_token(')');
4459                                 based = parse_microsoft_based();
4460                                 rem_anchor_token(')');
4461                                 expect(')', end_error);
4462                                 if (token.type != '*') {
4463                                         if (token.type == T__based) {
4464                                                 errorf(&pos, "__based type modifier specified more than once");
4465                                         } else if (warning.other) {
4466                                                 warningf(&pos,
4467                                                                 "__based does not precede a pointer declarator, ignored");
4468                                         }
4469                                         continue;
4470                                 }
4471                                 /* FALLTHROUGH */
4472                         }
4473
4474                         case '*':
4475                                 type = parse_pointer_declarator(based);
4476                                 break;
4477
4478                         default:
4479                                 goto ptr_operator_end;
4480                 }
4481
4482                 *anchor = type;
4483                 anchor  = &type->base.next;
4484
4485                 /* TODO: find out if this is correct */
4486                 modifiers |= parse_attributes(&attributes);
4487         }
4488 ptr_operator_end:
4489
4490         if (env != NULL) {
4491                 modifiers      |= env->modifiers;
4492                 env->modifiers  = modifiers;
4493         }
4494
4495         construct_type_t *inner_types = NULL;
4496
4497         switch (token.type) {
4498         case T_IDENTIFIER:
4499                 if (env == NULL) {
4500                         errorf(HERE, "no identifier expected in typename");
4501                 } else {
4502                         env->symbol          = token.v.symbol;
4503                         env->source_position = token.source_position;
4504                 }
4505                 next_token();
4506                 break;
4507         case '(':
4508                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4509                  * interpreted as ``function with no parameter specification'', rather
4510                  * than redundant parentheses around the omitted identifier. */
4511                 if (look_ahead(1)->type != ')') {
4512                         next_token();
4513                         add_anchor_token(')');
4514                         inner_types = parse_inner_declarator(env, may_be_abstract);
4515                         if (inner_types != NULL) {
4516                                 /* All later declarators only modify the return type */
4517                                 env = NULL;
4518                         }
4519                         rem_anchor_token(')');
4520                         expect(')', end_error);
4521                 }
4522                 break;
4523         default:
4524                 if (may_be_abstract)
4525                         break;
4526                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4527                 eat_until_anchor();
4528                 return NULL;
4529         }
4530
4531         construct_type_t **const p = anchor;
4532
4533         for (;;) {
4534                 construct_type_t *type;
4535                 switch (token.type) {
4536                 case '(': {
4537                         scope_t *scope = NULL;
4538                         if (env != NULL)
4539                                 scope = &env->parameters;
4540
4541                         type = parse_function_declarator(scope, modifiers);
4542                         break;
4543                 }
4544                 case '[':
4545                         type = parse_array_declarator();
4546                         break;
4547                 default:
4548                         goto declarator_finished;
4549                 }
4550
4551                 /* insert in the middle of the list (at p) */
4552                 type->base.next = *p;
4553                 *p              = type;
4554                 if (anchor == p)
4555                         anchor = &type->base.next;
4556         }
4557
4558 declarator_finished:
4559         /* append inner_types at the end of the list, we don't to set anchor anymore
4560          * as it's not needed anymore */
4561         *anchor = inner_types;
4562
4563         return first;
4564 end_error:
4565         return NULL;
4566 }
4567
4568 static void parse_declaration_attributes(entity_t *entity)
4569 {
4570         gnu_attribute_t  *attributes = NULL;
4571         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4572
4573         if (entity == NULL)
4574                 return;
4575
4576         type_t *type;
4577         if (entity->kind == ENTITY_TYPEDEF) {
4578                 modifiers |= entity->typedefe.modifiers;
4579                 type       = entity->typedefe.type;
4580         } else {
4581                 assert(is_declaration(entity));
4582                 modifiers |= entity->declaration.modifiers;
4583                 type       = entity->declaration.type;
4584         }
4585         if (type == NULL)
4586                 return;
4587
4588         gnu_attribute_t *attribute = attributes;
4589         for ( ; attribute != NULL; attribute = attribute->next) {
4590                 if (attribute->invalid)
4591                         continue;
4592
4593                 if (attribute->kind == GNU_AK_MODE) {
4594                         type = handle_attribute_mode(attribute, type);
4595                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4596                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4597                         if (attribute->has_arguments)
4598                                 alignment = attribute->u.argument;
4599
4600                         if (entity->kind == ENTITY_TYPEDEF) {
4601                                 type_t *copy         = duplicate_type(type);
4602                                 copy->base.alignment = attribute->u.argument;
4603                                 type                 = identify_new_type(copy);
4604                         } else if(entity->kind == ENTITY_VARIABLE) {
4605                                 entity->variable.alignment = alignment;
4606                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4607                                 entity->compound_member.alignment = alignment;
4608                         }
4609                 }
4610         }
4611
4612         type_modifiers_t type_modifiers = type->base.modifiers;
4613         if (modifiers & DM_TRANSPARENT_UNION)
4614                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4615
4616         if (type->base.modifiers != type_modifiers) {
4617                 type_t *copy         = duplicate_type(type);
4618                 copy->base.modifiers = type_modifiers;
4619                 type                 = identify_new_type(copy);
4620         }
4621
4622         if (entity->kind == ENTITY_TYPEDEF) {
4623                 entity->typedefe.type      = type;
4624                 entity->typedefe.modifiers = modifiers;
4625         } else {
4626                 entity->declaration.type      = type;
4627                 entity->declaration.modifiers = modifiers;
4628         }
4629 }
4630
4631 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4632 {
4633         construct_type_t *iter = construct_list;
4634         for (; iter != NULL; iter = iter->base.next) {
4635                 switch (iter->kind) {
4636                 case CONSTRUCT_INVALID:
4637                         break;
4638                 case CONSTRUCT_FUNCTION: {
4639                         construct_function_type_t *function      = &iter->function;
4640                         type_t                    *function_type = function->function_type;
4641
4642                         function_type->function.return_type = type;
4643
4644                         type_t *skipped_return_type = skip_typeref(type);
4645                         /* §6.7.5.3:1 */
4646                         if (is_type_function(skipped_return_type)) {
4647                                 errorf(HERE, "function returning function is not allowed");
4648                         } else if (is_type_array(skipped_return_type)) {
4649                                 errorf(HERE, "function returning array is not allowed");
4650                         } else {
4651                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4652                                         warningf(HERE,
4653                                                 "type qualifiers in return type of function type are meaningless");
4654                                 }
4655                         }
4656
4657                         /* The function type was constructed earlier.  Freeing it here will
4658                          * destroy other types. */
4659                         type = typehash_insert(function_type);
4660                         continue;
4661                 }
4662
4663                 case CONSTRUCT_POINTER: {
4664                         if (is_type_reference(skip_typeref(type)))
4665                                 errorf(HERE, "cannot declare a pointer to reference");
4666
4667                         parsed_pointer_t *pointer = &iter->pointer;
4668                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
4669                         continue;
4670                 }
4671
4672                 case CONSTRUCT_REFERENCE:
4673                         if (is_type_reference(skip_typeref(type)))
4674                                 errorf(HERE, "cannot declare a reference to reference");
4675
4676                         type = make_reference_type(type);
4677                         continue;
4678
4679                 case CONSTRUCT_ARRAY: {
4680                         if (is_type_reference(skip_typeref(type)))
4681                                 errorf(HERE, "cannot declare an array of references");
4682
4683                         parsed_array_t *array      = &iter->array;
4684                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
4685
4686                         expression_t *size_expression = array->size;
4687                         if (size_expression != NULL) {
4688                                 size_expression
4689                                         = create_implicit_cast(size_expression, type_size_t);
4690                         }
4691
4692                         array_type->base.qualifiers       = array->type_qualifiers;
4693                         array_type->array.element_type    = type;
4694                         array_type->array.is_static       = array->is_static;
4695                         array_type->array.is_variable     = array->is_variable;
4696                         array_type->array.size_expression = size_expression;
4697
4698                         if (size_expression != NULL) {
4699                                 if (is_constant_expression(size_expression)) {
4700                                         long const size                 = fold_constant(size_expression);
4701                                         array_type->array.size          = size;
4702                                         array_type->array.size_constant = true;
4703                                         /* §6.7.5.2:1  If the expression is a constant expression, it shall
4704                                          * have a value greater than zero. */
4705                                         if (size <= 0) {
4706                                                 if (size < 0 || !GNU_MODE) {
4707                                                         errorf(&size_expression->base.source_position,
4708                                                                         "size of array must be greater than zero");
4709                                                 } else if (warning.other) {
4710                                                         warningf(&size_expression->base.source_position,
4711                                                                         "zero length arrays are a GCC extension");
4712                                                 }
4713                                         }
4714                                 } else {
4715                                         array_type->array.is_vla = true;
4716                                 }
4717                         }
4718
4719                         type_t *skipped_type = skip_typeref(type);
4720                         /* §6.7.5.2:1 */
4721                         if (is_type_incomplete(skipped_type)) {
4722                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4723                         } else if (is_type_function(skipped_type)) {
4724                                 errorf(HERE, "array of functions is not allowed");
4725                         }
4726                         type = identify_new_type(array_type);
4727                         continue;
4728                 }
4729                 }
4730                 internal_errorf(HERE, "invalid type construction found");
4731         }
4732
4733         return type;
4734 }
4735
4736 static type_t *automatic_type_conversion(type_t *orig_type);
4737
4738 static type_t *semantic_parameter(const source_position_t *pos,
4739                                   type_t *type,
4740                                   const declaration_specifiers_t *specifiers,
4741                                   symbol_t *symbol)
4742 {
4743         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4744          *             shall be adjusted to ``qualified pointer to type'',
4745          *             [...]
4746          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4747          *             type'' shall be adjusted to ``pointer to function
4748          *             returning type'', as in 6.3.2.1. */
4749         type = automatic_type_conversion(type);
4750
4751         if (specifiers->is_inline && is_type_valid(type)) {
4752                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
4753         }
4754
4755         /* §6.9.1:6  The declarations in the declaration list shall contain
4756          *           no storage-class specifier other than register and no
4757          *           initializations. */
4758         if (specifiers->thread_local || (
4759                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4760                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4761            ) {
4762                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
4763         }
4764
4765         /* delay test for incomplete type, because we might have (void)
4766          * which is legal but incomplete... */
4767
4768         return type;
4769 }
4770
4771 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4772                                   declarator_flags_t flags)
4773 {
4774         parse_declarator_env_t env;
4775         memset(&env, 0, sizeof(env));
4776         env.modifiers = specifiers->modifiers;
4777
4778         construct_type_t *construct_type =
4779                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4780         type_t           *orig_type      =
4781                 construct_declarator_type(construct_type, specifiers->type);
4782         type_t           *type           = skip_typeref(orig_type);
4783
4784         if (construct_type != NULL) {
4785                 obstack_free(&temp_obst, construct_type);
4786         }
4787
4788         entity_t *entity;
4789         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4790                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4791                 entity->base.symbol          = env.symbol;
4792                 entity->base.source_position = env.source_position;
4793                 entity->typedefe.type        = orig_type;
4794
4795                 if (anonymous_entity != NULL) {
4796                         if (is_type_compound(type)) {
4797                                 assert(anonymous_entity->compound.alias == NULL);
4798                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4799                                        anonymous_entity->kind == ENTITY_UNION);
4800                                 anonymous_entity->compound.alias = entity;
4801                                 anonymous_entity = NULL;
4802                         } else if (is_type_enum(type)) {
4803                                 assert(anonymous_entity->enume.alias == NULL);
4804                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4805                                 anonymous_entity->enume.alias = entity;
4806                                 anonymous_entity = NULL;
4807                         }
4808                 }
4809         } else {
4810                 /* create a declaration type entity */
4811                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4812                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4813
4814                         if (env.symbol != NULL) {
4815                                 if (specifiers->is_inline && is_type_valid(type)) {
4816                                         errorf(&env.source_position,
4817                                                         "compound member '%Y' declared 'inline'", env.symbol);
4818                                 }
4819
4820                                 if (specifiers->thread_local ||
4821                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4822                                         errorf(&env.source_position,
4823                                                         "compound member '%Y' must have no storage class",
4824                                                         env.symbol);
4825                                 }
4826                         }
4827                 } else if (flags & DECL_IS_PARAMETER) {
4828                         orig_type = semantic_parameter(&env.source_position, orig_type,
4829                                                        specifiers, env.symbol);
4830
4831                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4832                 } else if (is_type_function(type)) {
4833                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4834
4835                         entity->function.is_inline  = specifiers->is_inline;
4836                         entity->function.parameters = env.parameters;
4837
4838                         if (env.symbol != NULL) {
4839                                 if (specifiers->thread_local || (
4840                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4841                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4842                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4843                                                 )) {
4844                                         errorf(&env.source_position,
4845                                                         "invalid storage class for function '%Y'", env.symbol);
4846                                 }
4847                         }
4848                 } else {
4849                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4850
4851                         entity->variable.get_property_sym = specifiers->get_property_sym;
4852                         entity->variable.put_property_sym = specifiers->put_property_sym;
4853
4854                         entity->variable.thread_local = specifiers->thread_local;
4855
4856                         if (env.symbol != NULL) {
4857                                 if (specifiers->is_inline && is_type_valid(type)) {
4858                                         errorf(&env.source_position,
4859                                                         "variable '%Y' declared 'inline'", env.symbol);
4860                                 }
4861
4862                                 bool invalid_storage_class = false;
4863                                 if (current_scope == file_scope) {
4864                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4865                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4866                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4867                                                 invalid_storage_class = true;
4868                                         }
4869                                 } else {
4870                                         if (specifiers->thread_local &&
4871                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4872                                                 invalid_storage_class = true;
4873                                         }
4874                                 }
4875                                 if (invalid_storage_class) {
4876                                         errorf(&env.source_position,
4877                                                         "invalid storage class for variable '%Y'", env.symbol);
4878                                 }
4879                         }
4880                 }
4881
4882                 if (env.symbol != NULL) {
4883                         entity->base.symbol          = env.symbol;
4884                         entity->base.source_position = env.source_position;
4885                 } else {
4886                         entity->base.source_position = specifiers->source_position;
4887                 }
4888                 entity->base.namespc                  = NAMESPACE_NORMAL;
4889                 entity->declaration.type              = orig_type;
4890                 entity->declaration.modifiers         = env.modifiers;
4891                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4892
4893                 storage_class_t storage_class = specifiers->storage_class;
4894                 entity->declaration.declared_storage_class = storage_class;
4895
4896                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4897                         storage_class = STORAGE_CLASS_AUTO;
4898                 entity->declaration.storage_class = storage_class;
4899         }
4900
4901         parse_declaration_attributes(entity);
4902
4903         return entity;
4904 }
4905
4906 static type_t *parse_abstract_declarator(type_t *base_type)
4907 {
4908         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4909
4910         type_t *result = construct_declarator_type(construct_type, base_type);
4911         if (construct_type != NULL) {
4912                 obstack_free(&temp_obst, construct_type);
4913         }
4914
4915         return result;
4916 }
4917
4918 /**
4919  * Check if the declaration of main is suspicious.  main should be a
4920  * function with external linkage, returning int, taking either zero
4921  * arguments, two, or three arguments of appropriate types, ie.
4922  *
4923  * int main([ int argc, char **argv [, char **env ] ]).
4924  *
4925  * @param decl    the declaration to check
4926  * @param type    the function type of the declaration
4927  */
4928 static void check_type_of_main(const entity_t *entity)
4929 {
4930         const source_position_t *pos = &entity->base.source_position;
4931         if (entity->kind != ENTITY_FUNCTION) {
4932                 warningf(pos, "'main' is not a function");
4933                 return;
4934         }
4935
4936         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4937                 warningf(pos, "'main' is normally a non-static function");
4938         }
4939
4940         type_t *type = skip_typeref(entity->declaration.type);
4941         assert(is_type_function(type));
4942
4943         function_type_t *func_type = &type->function;
4944         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4945                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4946                          func_type->return_type);
4947         }
4948         const function_parameter_t *parm = func_type->parameters;
4949         if (parm != NULL) {
4950                 type_t *const first_type = parm->type;
4951                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4952                         warningf(pos,
4953                                  "first argument of 'main' should be 'int', but is '%T'",
4954                                  first_type);
4955                 }
4956                 parm = parm->next;
4957                 if (parm != NULL) {
4958                         type_t *const second_type = parm->type;
4959                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4960                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4961                         }
4962                         parm = parm->next;
4963                         if (parm != NULL) {
4964                                 type_t *const third_type = parm->type;
4965                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4966                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4967                                 }
4968                                 parm = parm->next;
4969                                 if (parm != NULL)
4970                                         goto warn_arg_count;
4971                         }
4972                 } else {
4973 warn_arg_count:
4974                         warningf(pos, "'main' takes only zero, two or three arguments");
4975                 }
4976         }
4977 }
4978
4979 /**
4980  * Check if a symbol is the equal to "main".
4981  */
4982 static bool is_sym_main(const symbol_t *const sym)
4983 {
4984         return strcmp(sym->string, "main") == 0;
4985 }
4986
4987 static void error_redefined_as_different_kind(const source_position_t *pos,
4988                 const entity_t *old, entity_kind_t new_kind)
4989 {
4990         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4991                get_entity_kind_name(old->kind), old->base.symbol,
4992                get_entity_kind_name(new_kind), &old->base.source_position);
4993 }
4994
4995 static bool is_error_entity(entity_t *const ent)
4996 {
4997         if (is_declaration(ent)) {
4998                 return is_type_valid(skip_typeref(ent->declaration.type));
4999         } else if (ent->kind == ENTITY_TYPEDEF) {
5000                 return is_type_valid(skip_typeref(ent->typedefe.type));
5001         }
5002         return false;
5003 }
5004
5005 /**
5006  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
5007  * for various problems that occur for multiple definitions
5008  */
5009 static entity_t *record_entity(entity_t *entity, const bool is_definition)
5010 {
5011         const symbol_t *const    symbol  = entity->base.symbol;
5012         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
5013         const source_position_t *pos     = &entity->base.source_position;
5014
5015         /* can happen in error cases */
5016         if (symbol == NULL)
5017                 return entity;
5018
5019         entity_t *const previous_entity = get_entity(symbol, namespc);
5020         /* pushing the same entity twice will break the stack structure */
5021         assert(previous_entity != entity);
5022
5023         if (entity->kind == ENTITY_FUNCTION) {
5024                 type_t *const orig_type = entity->declaration.type;
5025                 type_t *const type      = skip_typeref(orig_type);
5026
5027                 assert(is_type_function(type));
5028                 if (type->function.unspecified_parameters &&
5029                                 warning.strict_prototypes &&
5030                                 previous_entity == NULL) {
5031                         warningf(pos, "function declaration '%#T' is not a prototype",
5032                                          orig_type, symbol);
5033                 }
5034
5035                 if (warning.main && current_scope == file_scope
5036                                 && is_sym_main(symbol)) {
5037                         check_type_of_main(entity);
5038                 }
5039         }
5040
5041         if (is_declaration(entity) &&
5042                         warning.nested_externs &&
5043                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5044                         current_scope != file_scope) {
5045                 warningf(pos, "nested extern declaration of '%#T'",
5046                          entity->declaration.type, symbol);
5047         }
5048
5049         if (previous_entity != NULL) {
5050                 if (previous_entity->base.parent_scope == &current_function->parameters &&
5051                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5052                         assert(previous_entity->kind == ENTITY_PARAMETER);
5053                         errorf(pos,
5054                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5055                                         entity->declaration.type, symbol,
5056                                         previous_entity->declaration.type, symbol,
5057                                         &previous_entity->base.source_position);
5058                         goto finish;
5059                 }
5060
5061                 if (previous_entity->base.parent_scope == current_scope) {
5062                         if (previous_entity->kind != entity->kind) {
5063                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
5064                                         error_redefined_as_different_kind(pos, previous_entity,
5065                                                         entity->kind);
5066                                 }
5067                                 goto finish;
5068                         }
5069                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5070                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5071                                                 symbol, &previous_entity->base.source_position);
5072                                 goto finish;
5073                         }
5074                         if (previous_entity->kind == ENTITY_TYPEDEF) {
5075                                 /* TODO: C++ allows this for exactly the same type */
5076                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5077                                                 symbol, &previous_entity->base.source_position);
5078                                 goto finish;
5079                         }
5080
5081                         /* at this point we should have only VARIABLES or FUNCTIONS */
5082                         assert(is_declaration(previous_entity) && is_declaration(entity));
5083
5084                         declaration_t *const prev_decl = &previous_entity->declaration;
5085                         declaration_t *const decl      = &entity->declaration;
5086
5087                         /* can happen for K&R style declarations */
5088                         if (prev_decl->type       == NULL             &&
5089                                         previous_entity->kind == ENTITY_PARAMETER &&
5090                                         entity->kind          == ENTITY_PARAMETER) {
5091                                 prev_decl->type                   = decl->type;
5092                                 prev_decl->storage_class          = decl->storage_class;
5093                                 prev_decl->declared_storage_class = decl->declared_storage_class;
5094                                 prev_decl->modifiers              = decl->modifiers;
5095                                 prev_decl->deprecated_string      = decl->deprecated_string;
5096                                 return previous_entity;
5097                         }
5098
5099                         type_t *const orig_type = decl->type;
5100                         assert(orig_type != NULL);
5101                         type_t *const type      = skip_typeref(orig_type);
5102                         type_t *const prev_type = skip_typeref(prev_decl->type);
5103
5104                         if (!types_compatible(type, prev_type)) {
5105                                 errorf(pos,
5106                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
5107                                                 orig_type, symbol, prev_decl->type, symbol,
5108                                                 &previous_entity->base.source_position);
5109                         } else {
5110                                 unsigned old_storage_class = prev_decl->storage_class;
5111                                 if (warning.redundant_decls               &&
5112                                                 is_definition                     &&
5113                                                 !prev_decl->used                  &&
5114                                                 !(prev_decl->modifiers & DM_USED) &&
5115                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5116                                         warningf(&previous_entity->base.source_position,
5117                                                         "unnecessary static forward declaration for '%#T'",
5118                                                         prev_decl->type, symbol);
5119                                 }
5120
5121                                 storage_class_t new_storage_class = decl->storage_class;
5122
5123                                 /* pretend no storage class means extern for function
5124                                  * declarations (except if the previous declaration is neither
5125                                  * none nor extern) */
5126                                 if (entity->kind == ENTITY_FUNCTION) {
5127                                         /* the previous declaration could have unspecified parameters or
5128                                          * be a typedef, so use the new type */
5129                                         if (prev_type->function.unspecified_parameters || is_definition)
5130                                                 prev_decl->type = type;
5131
5132                                         switch (old_storage_class) {
5133                                                 case STORAGE_CLASS_NONE:
5134                                                         old_storage_class = STORAGE_CLASS_EXTERN;
5135                                                         /* FALLTHROUGH */
5136
5137                                                 case STORAGE_CLASS_EXTERN:
5138                                                         if (is_definition) {
5139                                                                 if (warning.missing_prototypes &&
5140                                                                                 prev_type->function.unspecified_parameters &&
5141                                                                                 !is_sym_main(symbol)) {
5142                                                                         warningf(pos, "no previous prototype for '%#T'",
5143                                                                                         orig_type, symbol);
5144                                                                 }
5145                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5146                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5147                                                         }
5148                                                         break;
5149
5150                                                 default:
5151                                                         break;
5152                                         }
5153                                 } else if (is_type_incomplete(prev_type)) {
5154                                         prev_decl->type = type;
5155                                 }
5156
5157                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
5158                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
5159 warn_redundant_declaration:
5160                                         if (!is_definition           &&
5161                                                         warning.redundant_decls  &&
5162                                                         is_type_valid(prev_type) &&
5163                                                         strcmp(previous_entity->base.source_position.input_name,
5164                                                                 "<builtin>") != 0) {
5165                                                 warningf(pos,
5166                                                                 "redundant declaration for '%Y' (declared %P)",
5167                                                                 symbol, &previous_entity->base.source_position);
5168                                         }
5169                                 } else if (current_function == NULL) {
5170                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
5171                                                         new_storage_class == STORAGE_CLASS_STATIC) {
5172                                                 errorf(pos,
5173                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
5174                                                                 symbol, &previous_entity->base.source_position);
5175                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5176                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
5177                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5178                                         } else {
5179                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5180                                                 if (c_mode & _CXX)
5181                                                         goto error_redeclaration;
5182                                                 goto warn_redundant_declaration;
5183                                         }
5184                                 } else if (is_type_valid(prev_type)) {
5185                                         if (old_storage_class == new_storage_class) {
5186 error_redeclaration:
5187                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
5188                                                                 symbol, &previous_entity->base.source_position);
5189                                         } else {
5190                                                 errorf(pos,
5191                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
5192                                                                 symbol, &previous_entity->base.source_position);
5193                                         }
5194                                 }
5195                         }
5196
5197                         prev_decl->modifiers |= decl->modifiers;
5198                         if (entity->kind == ENTITY_FUNCTION) {
5199                                 previous_entity->function.is_inline |= entity->function.is_inline;
5200                         }
5201                         return previous_entity;
5202                 }
5203
5204                 if (warning.shadow) {
5205                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
5206                                         get_entity_kind_name(entity->kind), symbol,
5207                                         get_entity_kind_name(previous_entity->kind),
5208                                         &previous_entity->base.source_position);
5209                 }
5210         }
5211
5212         if (entity->kind == ENTITY_FUNCTION) {
5213                 if (is_definition &&
5214                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5215                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5216                                 warningf(pos, "no previous prototype for '%#T'",
5217                                          entity->declaration.type, symbol);
5218                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5219                                 warningf(pos, "no previous declaration for '%#T'",
5220                                          entity->declaration.type, symbol);
5221                         }
5222                 }
5223         } else if (warning.missing_declarations &&
5224                         entity->kind == ENTITY_VARIABLE &&
5225                         current_scope == file_scope) {
5226                 declaration_t *declaration = &entity->declaration;
5227                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5228                         warningf(pos, "no previous declaration for '%#T'",
5229                                  declaration->type, symbol);
5230                 }
5231         }
5232
5233 finish:
5234         assert(entity->base.parent_scope == NULL);
5235         assert(current_scope != NULL);
5236
5237         entity->base.parent_scope = current_scope;
5238         entity->base.namespc      = NAMESPACE_NORMAL;
5239         environment_push(entity);
5240         append_entity(current_scope, entity);
5241
5242         return entity;
5243 }
5244
5245 static void parser_error_multiple_definition(entity_t *entity,
5246                 const source_position_t *source_position)
5247 {
5248         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5249                entity->base.symbol, &entity->base.source_position);
5250 }
5251
5252 static bool is_declaration_specifier(const token_t *token,
5253                                      bool only_specifiers_qualifiers)
5254 {
5255         switch (token->type) {
5256                 TYPE_SPECIFIERS
5257                 TYPE_QUALIFIERS
5258                         return true;
5259                 case T_IDENTIFIER:
5260                         return is_typedef_symbol(token->v.symbol);
5261
5262                 case T___extension__:
5263                 STORAGE_CLASSES
5264                         return !only_specifiers_qualifiers;
5265
5266                 default:
5267                         return false;
5268         }
5269 }
5270
5271 static void parse_init_declarator_rest(entity_t *entity)
5272 {
5273         assert(is_declaration(entity));
5274         declaration_t *const declaration = &entity->declaration;
5275
5276         eat('=');
5277
5278         type_t *orig_type = declaration->type;
5279         type_t *type      = skip_typeref(orig_type);
5280
5281         if (entity->kind == ENTITY_VARIABLE
5282                         && entity->variable.initializer != NULL) {
5283                 parser_error_multiple_definition(entity, HERE);
5284         }
5285
5286         bool must_be_constant = false;
5287         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5288             entity->base.parent_scope  == file_scope) {
5289                 must_be_constant = true;
5290         }
5291
5292         if (is_type_function(type)) {
5293                 errorf(&entity->base.source_position,
5294                        "function '%#T' is initialized like a variable",
5295                        orig_type, entity->base.symbol);
5296                 orig_type = type_error_type;
5297         }
5298
5299         parse_initializer_env_t env;
5300         env.type             = orig_type;
5301         env.must_be_constant = must_be_constant;
5302         env.entity           = entity;
5303         current_init_decl    = entity;
5304
5305         initializer_t *initializer = parse_initializer(&env);
5306         current_init_decl = NULL;
5307
5308         if (entity->kind == ENTITY_VARIABLE) {
5309                 /* §6.7.5:22  array initializers for arrays with unknown size
5310                  * determine the array type size */
5311                 declaration->type            = env.type;
5312                 entity->variable.initializer = initializer;
5313         }
5314 }
5315
5316 /* parse rest of a declaration without any declarator */
5317 static void parse_anonymous_declaration_rest(
5318                 const declaration_specifiers_t *specifiers)
5319 {
5320         eat(';');
5321         anonymous_entity = NULL;
5322
5323         if (warning.other) {
5324                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5325                                 specifiers->thread_local) {
5326                         warningf(&specifiers->source_position,
5327                                  "useless storage class in empty declaration");
5328                 }
5329
5330                 type_t *type = specifiers->type;
5331                 switch (type->kind) {
5332                         case TYPE_COMPOUND_STRUCT:
5333                         case TYPE_COMPOUND_UNION: {
5334                                 if (type->compound.compound->base.symbol == NULL) {
5335                                         warningf(&specifiers->source_position,
5336                                                  "unnamed struct/union that defines no instances");
5337                                 }
5338                                 break;
5339                         }
5340
5341                         case TYPE_ENUM:
5342                                 break;
5343
5344                         default:
5345                                 warningf(&specifiers->source_position, "empty declaration");
5346                                 break;
5347                 }
5348         }
5349 }
5350
5351 static void check_variable_type_complete(entity_t *ent)
5352 {
5353         if (ent->kind != ENTITY_VARIABLE)
5354                 return;
5355
5356         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5357          *         type for the object shall be complete [...] */
5358         declaration_t *decl = &ent->declaration;
5359         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
5360                         decl->storage_class == STORAGE_CLASS_STATIC)
5361                 return;
5362
5363         type_t *const orig_type = decl->type;
5364         type_t *const type      = skip_typeref(orig_type);
5365         if (!is_type_incomplete(type))
5366                 return;
5367
5368         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
5369          * are given length one. */
5370         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
5371                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5372                 return;
5373         }
5374
5375         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5376                         orig_type, ent->base.symbol);
5377 }
5378
5379
5380 static void parse_declaration_rest(entity_t *ndeclaration,
5381                 const declaration_specifiers_t *specifiers,
5382                 parsed_declaration_func         finished_declaration,
5383                 declarator_flags_t              flags)
5384 {
5385         add_anchor_token(';');
5386         add_anchor_token(',');
5387         while (true) {
5388                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5389
5390                 if (token.type == '=') {
5391                         parse_init_declarator_rest(entity);
5392                 } else if (entity->kind == ENTITY_VARIABLE) {
5393                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5394                          * [...] where the extern specifier is explicitly used. */
5395                         declaration_t *decl = &entity->declaration;
5396                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5397                                 type_t *type = decl->type;
5398                                 if (is_type_reference(skip_typeref(type))) {
5399                                         errorf(&entity->base.source_position,
5400                                                         "reference '%#T' must be initialized",
5401                                                         type, entity->base.symbol);
5402                                 }
5403                         }
5404                 }
5405
5406                 check_variable_type_complete(entity);
5407
5408                 if (token.type != ',')
5409                         break;
5410                 eat(',');
5411
5412                 add_anchor_token('=');
5413                 ndeclaration = parse_declarator(specifiers, flags);
5414                 rem_anchor_token('=');
5415         }
5416         expect(';', end_error);
5417
5418 end_error:
5419         anonymous_entity = NULL;
5420         rem_anchor_token(';');
5421         rem_anchor_token(',');
5422 }
5423
5424 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5425 {
5426         symbol_t *symbol = entity->base.symbol;
5427         if (symbol == NULL) {
5428                 errorf(HERE, "anonymous declaration not valid as function parameter");
5429                 return entity;
5430         }
5431
5432         assert(entity->base.namespc == NAMESPACE_NORMAL);
5433         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5434         if (previous_entity == NULL
5435                         || previous_entity->base.parent_scope != current_scope) {
5436                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5437                        symbol);
5438                 return entity;
5439         }
5440
5441         if (is_definition) {
5442                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5443         }
5444
5445         return record_entity(entity, false);
5446 }
5447
5448 static void parse_declaration(parsed_declaration_func finished_declaration,
5449                               declarator_flags_t      flags)
5450 {
5451         declaration_specifiers_t specifiers;
5452         memset(&specifiers, 0, sizeof(specifiers));
5453
5454         add_anchor_token(';');
5455         parse_declaration_specifiers(&specifiers);
5456         rem_anchor_token(';');
5457
5458         if (token.type == ';') {
5459                 parse_anonymous_declaration_rest(&specifiers);
5460         } else {
5461                 entity_t *entity = parse_declarator(&specifiers, flags);
5462                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5463         }
5464 }
5465
5466 static type_t *get_default_promoted_type(type_t *orig_type)
5467 {
5468         type_t *result = orig_type;
5469
5470         type_t *type = skip_typeref(orig_type);
5471         if (is_type_integer(type)) {
5472                 result = promote_integer(type);
5473         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
5474                 result = type_double;
5475         }
5476
5477         return result;
5478 }
5479
5480 static void parse_kr_declaration_list(entity_t *entity)
5481 {
5482         if (entity->kind != ENTITY_FUNCTION)
5483                 return;
5484
5485         type_t *type = skip_typeref(entity->declaration.type);
5486         assert(is_type_function(type));
5487         if (!type->function.kr_style_parameters)
5488                 return;
5489
5490
5491         add_anchor_token('{');
5492
5493         /* push function parameters */
5494         size_t const  top       = environment_top();
5495         scope_t      *old_scope = scope_push(&entity->function.parameters);
5496
5497         entity_t *parameter = entity->function.parameters.entities;
5498         for ( ; parameter != NULL; parameter = parameter->base.next) {
5499                 assert(parameter->base.parent_scope == NULL);
5500                 parameter->base.parent_scope = current_scope;
5501                 environment_push(parameter);
5502         }
5503
5504         /* parse declaration list */
5505         for (;;) {
5506                 switch (token.type) {
5507                         DECLARATION_START
5508                         case T___extension__:
5509                         /* This covers symbols, which are no type, too, and results in
5510                          * better error messages.  The typical cases are misspelled type
5511                          * names and missing includes. */
5512                         case T_IDENTIFIER:
5513                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5514                                 break;
5515                         default:
5516                                 goto decl_list_end;
5517                 }
5518         }
5519 decl_list_end:
5520
5521         /* pop function parameters */
5522         assert(current_scope == &entity->function.parameters);
5523         scope_pop(old_scope);
5524         environment_pop_to(top);
5525
5526         /* update function type */
5527         type_t *new_type = duplicate_type(type);
5528
5529         function_parameter_t  *parameters = NULL;
5530         function_parameter_t **anchor     = &parameters;
5531
5532         parameter = entity->function.parameters.entities;
5533         for (; parameter != NULL; parameter = parameter->base.next) {
5534                 if (parameter->kind != ENTITY_PARAMETER)
5535                         continue;
5536
5537                 type_t *parameter_type = parameter->declaration.type;
5538                 if (parameter_type == NULL) {
5539                         if (strict_mode) {
5540                                 errorf(HERE, "no type specified for function parameter '%Y'",
5541                                        parameter->base.symbol);
5542                         } else {
5543                                 if (warning.implicit_int) {
5544                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5545                                                  parameter->base.symbol);
5546                                 }
5547                                 parameter_type              = type_int;
5548                                 parameter->declaration.type = parameter_type;
5549                         }
5550                 }
5551
5552                 semantic_parameter_incomplete(parameter);
5553                 parameter_type = parameter->declaration.type;
5554
5555                 /*
5556                  * we need the default promoted types for the function type
5557                  */
5558                 parameter_type = get_default_promoted_type(parameter_type);
5559
5560                 function_parameter_t *const parameter =
5561                         allocate_parameter(parameter_type);
5562
5563                 *anchor = parameter;
5564                 anchor  = &parameter->next;
5565         }
5566
5567         /* §6.9.1.7: A K&R style parameter list does NOT act as a function
5568          * prototype */
5569         new_type->function.parameters             = parameters;
5570         new_type->function.unspecified_parameters = true;
5571
5572         new_type = identify_new_type(new_type);
5573
5574         entity->declaration.type = new_type;
5575
5576         rem_anchor_token('{');
5577 }
5578
5579 static bool first_err = true;
5580
5581 /**
5582  * When called with first_err set, prints the name of the current function,
5583  * else does noting.
5584  */
5585 static void print_in_function(void)
5586 {
5587         if (first_err) {
5588                 first_err = false;
5589                 diagnosticf("%s: In function '%Y':\n",
5590                             current_function->base.base.source_position.input_name,
5591                             current_function->base.base.symbol);
5592         }
5593 }
5594
5595 /**
5596  * Check if all labels are defined in the current function.
5597  * Check if all labels are used in the current function.
5598  */
5599 static void check_labels(void)
5600 {
5601         for (const goto_statement_t *goto_statement = goto_first;
5602             goto_statement != NULL;
5603             goto_statement = goto_statement->next) {
5604                 /* skip computed gotos */
5605                 if (goto_statement->expression != NULL)
5606                         continue;
5607
5608                 label_t *label = goto_statement->label;
5609
5610                 label->used = true;
5611                 if (label->base.source_position.input_name == NULL) {
5612                         print_in_function();
5613                         errorf(&goto_statement->base.source_position,
5614                                "label '%Y' used but not defined", label->base.symbol);
5615                  }
5616         }
5617
5618         if (warning.unused_label) {
5619                 for (const label_statement_t *label_statement = label_first;
5620                          label_statement != NULL;
5621                          label_statement = label_statement->next) {
5622                         label_t *label = label_statement->label;
5623
5624                         if (! label->used) {
5625                                 print_in_function();
5626                                 warningf(&label_statement->base.source_position,
5627                                          "label '%Y' defined but not used", label->base.symbol);
5628                         }
5629                 }
5630         }
5631 }
5632
5633 static void warn_unused_entity(entity_t *entity, entity_t *last)
5634 {
5635         entity_t const *const end = last != NULL ? last->base.next : NULL;
5636         for (; entity != end; entity = entity->base.next) {
5637                 if (!is_declaration(entity))
5638                         continue;
5639
5640                 declaration_t *declaration = &entity->declaration;
5641                 if (declaration->implicit)
5642                         continue;
5643
5644                 if (!declaration->used) {
5645                         print_in_function();
5646                         const char *what = get_entity_kind_name(entity->kind);
5647                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5648                                  what, entity->base.symbol);
5649                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5650                         print_in_function();
5651                         const char *what = get_entity_kind_name(entity->kind);
5652                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5653                                  what, entity->base.symbol);
5654                 }
5655         }
5656 }
5657
5658 static void check_unused_variables(statement_t *const stmt, void *const env)
5659 {
5660         (void)env;
5661
5662         switch (stmt->kind) {
5663                 case STATEMENT_DECLARATION: {
5664                         declaration_statement_t const *const decls = &stmt->declaration;
5665                         warn_unused_entity(decls->declarations_begin,
5666                                            decls->declarations_end);
5667                         return;
5668                 }
5669
5670                 case STATEMENT_FOR:
5671                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5672                         return;
5673
5674                 default:
5675                         return;
5676         }
5677 }
5678
5679 /**
5680  * Check declarations of current_function for unused entities.
5681  */
5682 static void check_declarations(void)
5683 {
5684         if (warning.unused_parameter) {
5685                 const scope_t *scope = &current_function->parameters;
5686
5687                 /* do not issue unused warnings for main */
5688                 if (!is_sym_main(current_function->base.base.symbol)) {
5689                         warn_unused_entity(scope->entities, NULL);
5690                 }
5691         }
5692         if (warning.unused_variable) {
5693                 walk_statements(current_function->statement, check_unused_variables,
5694                                 NULL);
5695         }
5696 }
5697
5698 static int determine_truth(expression_t const* const cond)
5699 {
5700         return
5701                 !is_constant_expression(cond) ? 0 :
5702                 fold_constant(cond) != 0      ? 1 :
5703                 -1;
5704 }
5705
5706 static void check_reachable(statement_t *);
5707 static bool reaches_end;
5708
5709 static bool expression_returns(expression_t const *const expr)
5710 {
5711         switch (expr->kind) {
5712                 case EXPR_CALL: {
5713                         expression_t const *const func = expr->call.function;
5714                         if (func->kind == EXPR_REFERENCE) {
5715                                 entity_t *entity = func->reference.entity;
5716                                 if (entity->kind == ENTITY_FUNCTION
5717                                                 && entity->declaration.modifiers & DM_NORETURN)
5718                                         return false;
5719                         }
5720
5721                         if (!expression_returns(func))
5722                                 return false;
5723
5724                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5725                                 if (!expression_returns(arg->expression))
5726                                         return false;
5727                         }
5728
5729                         return true;
5730                 }
5731
5732                 case EXPR_REFERENCE:
5733                 case EXPR_REFERENCE_ENUM_VALUE:
5734                 case EXPR_CONST:
5735                 case EXPR_CHARACTER_CONSTANT:
5736                 case EXPR_WIDE_CHARACTER_CONSTANT:
5737                 case EXPR_STRING_LITERAL:
5738                 case EXPR_WIDE_STRING_LITERAL:
5739                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5740                 case EXPR_LABEL_ADDRESS:
5741                 case EXPR_CLASSIFY_TYPE:
5742                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5743                 case EXPR_ALIGNOF:
5744                 case EXPR_FUNCNAME:
5745                 case EXPR_BUILTIN_CONSTANT_P:
5746                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5747                 case EXPR_OFFSETOF:
5748                 case EXPR_INVALID:
5749                         return true;
5750
5751                 case EXPR_STATEMENT: {
5752                         bool old_reaches_end = reaches_end;
5753                         reaches_end = false;
5754                         check_reachable(expr->statement.statement);
5755                         bool returns = reaches_end;
5756                         reaches_end = old_reaches_end;
5757                         return returns;
5758                 }
5759
5760                 case EXPR_CONDITIONAL:
5761                         // TODO handle constant expression
5762
5763                         if (!expression_returns(expr->conditional.condition))
5764                                 return false;
5765
5766                         if (expr->conditional.true_expression != NULL
5767                                         && expression_returns(expr->conditional.true_expression))
5768                                 return true;
5769
5770                         return expression_returns(expr->conditional.false_expression);
5771
5772                 case EXPR_SELECT:
5773                         return expression_returns(expr->select.compound);
5774
5775                 case EXPR_ARRAY_ACCESS:
5776                         return
5777                                 expression_returns(expr->array_access.array_ref) &&
5778                                 expression_returns(expr->array_access.index);
5779
5780                 case EXPR_VA_START:
5781                         return expression_returns(expr->va_starte.ap);
5782
5783                 case EXPR_VA_ARG:
5784                         return expression_returns(expr->va_arge.ap);
5785
5786                 case EXPR_VA_COPY:
5787                         return expression_returns(expr->va_copye.src);
5788
5789                 EXPR_UNARY_CASES_MANDATORY
5790                         return expression_returns(expr->unary.value);
5791
5792                 case EXPR_UNARY_THROW:
5793                         return false;
5794
5795                 EXPR_BINARY_CASES
5796                         // TODO handle constant lhs of && and ||
5797                         return
5798                                 expression_returns(expr->binary.left) &&
5799                                 expression_returns(expr->binary.right);
5800
5801                 case EXPR_UNKNOWN:
5802                         break;
5803         }
5804
5805         panic("unhandled expression");
5806 }
5807
5808 static bool initializer_returns(initializer_t const *const init)
5809 {
5810         switch (init->kind) {
5811                 case INITIALIZER_VALUE:
5812                         return expression_returns(init->value.value);
5813
5814                 case INITIALIZER_LIST: {
5815                         initializer_t * const*       i       = init->list.initializers;
5816                         initializer_t * const* const end     = i + init->list.len;
5817                         bool                         returns = true;
5818                         for (; i != end; ++i) {
5819                                 if (!initializer_returns(*i))
5820                                         returns = false;
5821                         }
5822                         return returns;
5823                 }
5824
5825                 case INITIALIZER_STRING:
5826                 case INITIALIZER_WIDE_STRING:
5827                 case INITIALIZER_DESIGNATOR: // designators have no payload
5828                         return true;
5829         }
5830         panic("unhandled initializer");
5831 }
5832
5833 static bool noreturn_candidate;
5834
5835 static void check_reachable(statement_t *const stmt)
5836 {
5837         if (stmt->base.reachable)
5838                 return;
5839         if (stmt->kind != STATEMENT_DO_WHILE)
5840                 stmt->base.reachable = true;
5841
5842         statement_t *last = stmt;
5843         statement_t *next;
5844         switch (stmt->kind) {
5845                 case STATEMENT_INVALID:
5846                 case STATEMENT_EMPTY:
5847                 case STATEMENT_ASM:
5848                         next = stmt->base.next;
5849                         break;
5850
5851                 case STATEMENT_DECLARATION: {
5852                         declaration_statement_t const *const decl = &stmt->declaration;
5853                         entity_t                const *      ent  = decl->declarations_begin;
5854                         entity_t                const *const last = decl->declarations_end;
5855                         if (ent != NULL) {
5856                                 for (;; ent = ent->base.next) {
5857                                         if (ent->kind                 == ENTITY_VARIABLE &&
5858                                                         ent->variable.initializer != NULL            &&
5859                                                         !initializer_returns(ent->variable.initializer)) {
5860                                                 return;
5861                                         }
5862                                         if (ent == last)
5863                                                 break;
5864                                 }
5865                         }
5866                         next = stmt->base.next;
5867                         break;
5868                 }
5869
5870                 case STATEMENT_COMPOUND:
5871                         next = stmt->compound.statements;
5872                         if (next == NULL)
5873                                 next = stmt->base.next;
5874                         break;
5875
5876                 case STATEMENT_RETURN: {
5877                         expression_t const *const val = stmt->returns.value;
5878                         if (val == NULL || expression_returns(val))
5879                                 noreturn_candidate = false;
5880                         return;
5881                 }
5882
5883                 case STATEMENT_IF: {
5884                         if_statement_t const *const ifs  = &stmt->ifs;
5885                         expression_t   const *const cond = ifs->condition;
5886
5887                         if (!expression_returns(cond))
5888                                 return;
5889
5890                         int const val = determine_truth(cond);
5891
5892                         if (val >= 0)
5893                                 check_reachable(ifs->true_statement);
5894
5895                         if (val > 0)
5896                                 return;
5897
5898                         if (ifs->false_statement != NULL) {
5899                                 check_reachable(ifs->false_statement);
5900                                 return;
5901                         }
5902
5903                         next = stmt->base.next;
5904                         break;
5905                 }
5906
5907                 case STATEMENT_SWITCH: {
5908                         switch_statement_t const *const switchs = &stmt->switchs;
5909                         expression_t       const *const expr    = switchs->expression;
5910
5911                         if (!expression_returns(expr))
5912                                 return;
5913
5914                         if (is_constant_expression(expr)) {
5915                                 long                    const val      = fold_constant(expr);
5916                                 case_label_statement_t *      defaults = NULL;
5917                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5918                                         if (i->expression == NULL) {
5919                                                 defaults = i;
5920                                                 continue;
5921                                         }
5922
5923                                         if (i->first_case <= val && val <= i->last_case) {
5924                                                 check_reachable((statement_t*)i);
5925                                                 return;
5926                                         }
5927                                 }
5928
5929                                 if (defaults != NULL) {
5930                                         check_reachable((statement_t*)defaults);
5931                                         return;
5932                                 }
5933                         } else {
5934                                 bool has_default = false;
5935                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5936                                         if (i->expression == NULL)
5937                                                 has_default = true;
5938
5939                                         check_reachable((statement_t*)i);
5940                                 }
5941
5942                                 if (has_default)
5943                                         return;
5944                         }
5945
5946                         next = stmt->base.next;
5947                         break;
5948                 }
5949
5950                 case STATEMENT_EXPRESSION: {
5951                         /* Check for noreturn function call */
5952                         expression_t const *const expr = stmt->expression.expression;
5953                         if (!expression_returns(expr))
5954                                 return;
5955
5956                         next = stmt->base.next;
5957                         break;
5958                 }
5959
5960                 case STATEMENT_CONTINUE: {
5961                         statement_t *parent = stmt;
5962                         for (;;) {
5963                                 parent = parent->base.parent;
5964                                 if (parent == NULL) /* continue not within loop */
5965                                         return;
5966
5967                                 next = parent;
5968                                 switch (parent->kind) {
5969                                         case STATEMENT_WHILE:    goto continue_while;
5970                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5971                                         case STATEMENT_FOR:      goto continue_for;
5972
5973                                         default: break;
5974                                 }
5975                         }
5976                 }
5977
5978                 case STATEMENT_BREAK: {
5979                         statement_t *parent = stmt;
5980                         for (;;) {
5981                                 parent = parent->base.parent;
5982                                 if (parent == NULL) /* break not within loop/switch */
5983                                         return;
5984
5985                                 switch (parent->kind) {
5986                                         case STATEMENT_SWITCH:
5987                                         case STATEMENT_WHILE:
5988                                         case STATEMENT_DO_WHILE:
5989                                         case STATEMENT_FOR:
5990                                                 last = parent;
5991                                                 next = parent->base.next;
5992                                                 goto found_break_parent;
5993
5994                                         default: break;
5995                                 }
5996                         }
5997 found_break_parent:
5998                         break;
5999                 }
6000
6001                 case STATEMENT_GOTO:
6002                         if (stmt->gotos.expression) {
6003                                 if (!expression_returns(stmt->gotos.expression))
6004                                         return;
6005
6006                                 statement_t *parent = stmt->base.parent;
6007                                 if (parent == NULL) /* top level goto */
6008                                         return;
6009                                 next = parent;
6010                         } else {
6011                                 next = stmt->gotos.label->statement;
6012                                 if (next == NULL) /* missing label */
6013                                         return;
6014                         }
6015                         break;
6016
6017                 case STATEMENT_LABEL:
6018                         next = stmt->label.statement;
6019                         break;
6020
6021                 case STATEMENT_CASE_LABEL:
6022                         next = stmt->case_label.statement;
6023                         break;
6024
6025                 case STATEMENT_WHILE: {
6026                         while_statement_t const *const whiles = &stmt->whiles;
6027                         expression_t      const *const cond   = whiles->condition;
6028
6029                         if (!expression_returns(cond))
6030                                 return;
6031
6032                         int const val = determine_truth(cond);
6033
6034                         if (val >= 0)
6035                                 check_reachable(whiles->body);
6036
6037                         if (val > 0)
6038                                 return;
6039
6040                         next = stmt->base.next;
6041                         break;
6042                 }
6043
6044                 case STATEMENT_DO_WHILE:
6045                         next = stmt->do_while.body;
6046                         break;
6047
6048                 case STATEMENT_FOR: {
6049                         for_statement_t *const fors = &stmt->fors;
6050
6051                         if (fors->condition_reachable)
6052                                 return;
6053                         fors->condition_reachable = true;
6054
6055                         expression_t const *const cond = fors->condition;
6056
6057                         int val;
6058                         if (cond == NULL) {
6059                                 val = 1;
6060                         } else if (expression_returns(cond)) {
6061                                 val = determine_truth(cond);
6062                         } else {
6063                                 return;
6064                         }
6065
6066                         if (val >= 0)
6067                                 check_reachable(fors->body);
6068
6069                         if (val > 0)
6070                                 return;
6071
6072                         next = stmt->base.next;
6073                         break;
6074                 }
6075
6076                 case STATEMENT_MS_TRY: {
6077                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6078                         check_reachable(ms_try->try_statement);
6079                         next = ms_try->final_statement;
6080                         break;
6081                 }
6082
6083                 case STATEMENT_LEAVE: {
6084                         statement_t *parent = stmt;
6085                         for (;;) {
6086                                 parent = parent->base.parent;
6087                                 if (parent == NULL) /* __leave not within __try */
6088                                         return;
6089
6090                                 if (parent->kind == STATEMENT_MS_TRY) {
6091                                         last = parent;
6092                                         next = parent->ms_try.final_statement;
6093                                         break;
6094                                 }
6095                         }
6096                         break;
6097                 }
6098
6099                 default:
6100                         panic("invalid statement kind");
6101         }
6102
6103         while (next == NULL) {
6104                 next = last->base.parent;
6105                 if (next == NULL) {
6106                         noreturn_candidate = false;
6107
6108                         type_t *const type = skip_typeref(current_function->base.type);
6109                         assert(is_type_function(type));
6110                         type_t *const ret  = skip_typeref(type->function.return_type);
6111                         if (warning.return_type                    &&
6112                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6113                             is_type_valid(ret)                     &&
6114                             !is_sym_main(current_function->base.base.symbol)) {
6115                                 warningf(&stmt->base.source_position,
6116                                          "control reaches end of non-void function");
6117                         }
6118                         return;
6119                 }
6120
6121                 switch (next->kind) {
6122                         case STATEMENT_INVALID:
6123                         case STATEMENT_EMPTY:
6124                         case STATEMENT_DECLARATION:
6125                         case STATEMENT_EXPRESSION:
6126                         case STATEMENT_ASM:
6127                         case STATEMENT_RETURN:
6128                         case STATEMENT_CONTINUE:
6129                         case STATEMENT_BREAK:
6130                         case STATEMENT_GOTO:
6131                         case STATEMENT_LEAVE:
6132                                 panic("invalid control flow in function");
6133
6134                         case STATEMENT_COMPOUND:
6135                                 if (next->compound.stmt_expr) {
6136                                         reaches_end = true;
6137                                         return;
6138                                 }
6139                                 /* FALLTHROUGH */
6140                         case STATEMENT_IF:
6141                         case STATEMENT_SWITCH:
6142                         case STATEMENT_LABEL:
6143                         case STATEMENT_CASE_LABEL:
6144                                 last = next;
6145                                 next = next->base.next;
6146                                 break;
6147
6148                         case STATEMENT_WHILE: {
6149 continue_while:
6150                                 if (next->base.reachable)
6151                                         return;
6152                                 next->base.reachable = true;
6153
6154                                 while_statement_t const *const whiles = &next->whiles;
6155                                 expression_t      const *const cond   = whiles->condition;
6156
6157                                 if (!expression_returns(cond))
6158                                         return;
6159
6160                                 int const val = determine_truth(cond);
6161
6162                                 if (val >= 0)
6163                                         check_reachable(whiles->body);
6164
6165                                 if (val > 0)
6166                                         return;
6167
6168                                 last = next;
6169                                 next = next->base.next;
6170                                 break;
6171                         }
6172
6173                         case STATEMENT_DO_WHILE: {
6174 continue_do_while:
6175                                 if (next->base.reachable)
6176                                         return;
6177                                 next->base.reachable = true;
6178
6179                                 do_while_statement_t const *const dw   = &next->do_while;
6180                                 expression_t         const *const cond = dw->condition;
6181
6182                                 if (!expression_returns(cond))
6183                                         return;
6184
6185                                 int const val = determine_truth(cond);
6186
6187                                 if (val >= 0)
6188                                         check_reachable(dw->body);
6189
6190                                 if (val > 0)
6191                                         return;
6192
6193                                 last = next;
6194                                 next = next->base.next;
6195                                 break;
6196                         }
6197
6198                         case STATEMENT_FOR: {
6199 continue_for:;
6200                                 for_statement_t *const fors = &next->fors;
6201
6202                                 fors->step_reachable = true;
6203
6204                                 if (fors->condition_reachable)
6205                                         return;
6206                                 fors->condition_reachable = true;
6207
6208                                 expression_t const *const cond = fors->condition;
6209
6210                                 int val;
6211                                 if (cond == NULL) {
6212                                         val = 1;
6213                                 } else if (expression_returns(cond)) {
6214                                         val = determine_truth(cond);
6215                                 } else {
6216                                         return;
6217                                 }
6218
6219                                 if (val >= 0)
6220                                         check_reachable(fors->body);
6221
6222                                 if (val > 0)
6223                                         return;
6224
6225                                 last = next;
6226                                 next = next->base.next;
6227                                 break;
6228                         }
6229
6230                         case STATEMENT_MS_TRY:
6231                                 last = next;
6232                                 next = next->ms_try.final_statement;
6233                                 break;
6234                 }
6235         }
6236
6237         check_reachable(next);
6238 }
6239
6240 static void check_unreachable(statement_t* const stmt, void *const env)
6241 {
6242         (void)env;
6243
6244         switch (stmt->kind) {
6245                 case STATEMENT_DO_WHILE:
6246                         if (!stmt->base.reachable) {
6247                                 expression_t const *const cond = stmt->do_while.condition;
6248                                 if (determine_truth(cond) >= 0) {
6249                                         warningf(&cond->base.source_position,
6250                                                  "condition of do-while-loop is unreachable");
6251                                 }
6252                         }
6253                         return;
6254
6255                 case STATEMENT_FOR: {
6256                         for_statement_t const* const fors = &stmt->fors;
6257
6258                         // if init and step are unreachable, cond is unreachable, too
6259                         if (!stmt->base.reachable && !fors->step_reachable) {
6260                                 warningf(&stmt->base.source_position, "statement is unreachable");
6261                         } else {
6262                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6263                                         warningf(&fors->initialisation->base.source_position,
6264                                                  "initialisation of for-statement is unreachable");
6265                                 }
6266
6267                                 if (!fors->condition_reachable && fors->condition != NULL) {
6268                                         warningf(&fors->condition->base.source_position,
6269                                                  "condition of for-statement is unreachable");
6270                                 }
6271
6272                                 if (!fors->step_reachable && fors->step != NULL) {
6273                                         warningf(&fors->step->base.source_position,
6274                                                  "step of for-statement is unreachable");
6275                                 }
6276                         }
6277                         return;
6278                 }
6279
6280                 case STATEMENT_COMPOUND:
6281                         if (stmt->compound.statements != NULL)
6282                                 return;
6283                         goto warn_unreachable;
6284
6285                 case STATEMENT_DECLARATION: {
6286                         /* Only warn if there is at least one declarator with an initializer.
6287                          * This typically occurs in switch statements. */
6288                         declaration_statement_t const *const decl = &stmt->declaration;
6289                         entity_t                const *      ent  = decl->declarations_begin;
6290                         entity_t                const *const last = decl->declarations_end;
6291                         if (ent != NULL) {
6292                                 for (;; ent = ent->base.next) {
6293                                         if (ent->kind                 == ENTITY_VARIABLE &&
6294                                                         ent->variable.initializer != NULL) {
6295                                                 goto warn_unreachable;
6296                                         }
6297                                         if (ent == last)
6298                                                 return;
6299                                 }
6300                         }
6301                 }
6302
6303                 default:
6304 warn_unreachable:
6305                         if (!stmt->base.reachable)
6306                                 warningf(&stmt->base.source_position, "statement is unreachable");
6307                         return;
6308         }
6309 }
6310
6311 static void parse_external_declaration(void)
6312 {
6313         /* function-definitions and declarations both start with declaration
6314          * specifiers */
6315         declaration_specifiers_t specifiers;
6316         memset(&specifiers, 0, sizeof(specifiers));
6317
6318         add_anchor_token(';');
6319         parse_declaration_specifiers(&specifiers);
6320         rem_anchor_token(';');
6321
6322         /* must be a declaration */
6323         if (token.type == ';') {
6324                 parse_anonymous_declaration_rest(&specifiers);
6325                 return;
6326         }
6327
6328         add_anchor_token(',');
6329         add_anchor_token('=');
6330         add_anchor_token(';');
6331         add_anchor_token('{');
6332
6333         /* declarator is common to both function-definitions and declarations */
6334         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6335
6336         rem_anchor_token('{');
6337         rem_anchor_token(';');
6338         rem_anchor_token('=');
6339         rem_anchor_token(',');
6340
6341         /* must be a declaration */
6342         switch (token.type) {
6343                 case ',':
6344                 case ';':
6345                 case '=':
6346                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6347                                         DECL_FLAGS_NONE);
6348                         return;
6349         }
6350
6351         /* must be a function definition */
6352         parse_kr_declaration_list(ndeclaration);
6353
6354         if (token.type != '{') {
6355                 parse_error_expected("while parsing function definition", '{', NULL);
6356                 eat_until_matching_token(';');
6357                 return;
6358         }
6359
6360         assert(is_declaration(ndeclaration));
6361         type_t *const orig_type = ndeclaration->declaration.type;
6362         type_t *      type      = skip_typeref(orig_type);
6363
6364         if (!is_type_function(type)) {
6365                 if (is_type_valid(type)) {
6366                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6367                                type, ndeclaration->base.symbol);
6368                 }
6369                 eat_block();
6370                 return;
6371         } else if (is_typeref(orig_type)) {
6372                 /* §6.9.1:2 */
6373                 errorf(&ndeclaration->base.source_position,
6374                                 "type of function definition '%#T' is a typedef",
6375                                 orig_type, ndeclaration->base.symbol);
6376         }
6377
6378         if (warning.aggregate_return &&
6379             is_type_compound(skip_typeref(type->function.return_type))) {
6380                 warningf(HERE, "function '%Y' returns an aggregate",
6381                          ndeclaration->base.symbol);
6382         }
6383         if (warning.traditional && !type->function.unspecified_parameters) {
6384                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6385                         ndeclaration->base.symbol);
6386         }
6387         if (warning.old_style_definition && type->function.unspecified_parameters) {
6388                 warningf(HERE, "old-style function definition '%Y'",
6389                         ndeclaration->base.symbol);
6390         }
6391
6392         /* §6.7.5.3:14 a function definition with () means no
6393          * parameters (and not unspecified parameters) */
6394         if (type->function.unspecified_parameters &&
6395                         type->function.parameters == NULL     &&
6396                         !type->function.kr_style_parameters) {
6397                 type_t *copy                          = duplicate_type(type);
6398                 copy->function.unspecified_parameters = false;
6399                 type                                  = identify_new_type(copy);
6400
6401                 ndeclaration->declaration.type = type;
6402         }
6403
6404         entity_t *const entity = record_entity(ndeclaration, true);
6405         assert(entity->kind == ENTITY_FUNCTION);
6406         assert(ndeclaration->kind == ENTITY_FUNCTION);
6407
6408         function_t *function = &entity->function;
6409         if (ndeclaration != entity) {
6410                 function->parameters = ndeclaration->function.parameters;
6411         }
6412         assert(is_declaration(entity));
6413         type = skip_typeref(entity->declaration.type);
6414
6415         /* push function parameters and switch scope */
6416         size_t const  top       = environment_top();
6417         scope_t      *old_scope = scope_push(&function->parameters);
6418
6419         entity_t *parameter = function->parameters.entities;
6420         for (; parameter != NULL; parameter = parameter->base.next) {
6421                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6422                         parameter->base.parent_scope = current_scope;
6423                 }
6424                 assert(parameter->base.parent_scope == NULL
6425                                 || parameter->base.parent_scope == current_scope);
6426                 parameter->base.parent_scope = current_scope;
6427                 if (parameter->base.symbol == NULL) {
6428                         errorf(&parameter->base.source_position, "parameter name omitted");
6429                         continue;
6430                 }
6431                 environment_push(parameter);
6432         }
6433
6434         if (function->statement != NULL) {
6435                 parser_error_multiple_definition(entity, HERE);
6436                 eat_block();
6437         } else {
6438                 /* parse function body */
6439                 int         label_stack_top      = label_top();
6440                 function_t *old_current_function = current_function;
6441                 current_function                 = function;
6442                 current_parent                   = NULL;
6443
6444                 goto_first   = NULL;
6445                 goto_anchor  = &goto_first;
6446                 label_first  = NULL;
6447                 label_anchor = &label_first;
6448
6449                 statement_t *const body = parse_compound_statement(false);
6450                 function->statement = body;
6451                 first_err = true;
6452                 check_labels();
6453                 check_declarations();
6454                 if (warning.return_type      ||
6455                     warning.unreachable_code ||
6456                     (warning.missing_noreturn
6457                      && !(function->base.modifiers & DM_NORETURN))) {
6458                         noreturn_candidate = true;
6459                         check_reachable(body);
6460                         if (warning.unreachable_code)
6461                                 walk_statements(body, check_unreachable, NULL);
6462                         if (warning.missing_noreturn &&
6463                             noreturn_candidate       &&
6464                             !(function->base.modifiers & DM_NORETURN)) {
6465                                 warningf(&body->base.source_position,
6466                                          "function '%#T' is candidate for attribute 'noreturn'",
6467                                          type, entity->base.symbol);
6468                         }
6469                 }
6470
6471                 assert(current_parent   == NULL);
6472                 assert(current_function == function);
6473                 current_function = old_current_function;
6474                 label_pop_to(label_stack_top);
6475         }
6476
6477         assert(current_scope == &function->parameters);
6478         scope_pop(old_scope);
6479         environment_pop_to(top);
6480 }
6481
6482 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6483                                   source_position_t *source_position,
6484                                   const symbol_t *symbol)
6485 {
6486         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6487
6488         type->bitfield.base_type       = base_type;
6489         type->bitfield.size_expression = size;
6490
6491         il_size_t bit_size;
6492         type_t *skipped_type = skip_typeref(base_type);
6493         if (!is_type_integer(skipped_type)) {
6494                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6495                         base_type);
6496                 bit_size = 0;
6497         } else {
6498                 bit_size = skipped_type->base.size * 8;
6499         }
6500
6501         if (is_constant_expression(size)) {
6502                 long v = fold_constant(size);
6503
6504                 if (v < 0) {
6505                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6506                 } else if (v == 0) {
6507                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6508                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6509                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6510                 } else {
6511                         type->bitfield.bit_size = v;
6512                 }
6513         }
6514
6515         return type;
6516 }
6517
6518 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6519 {
6520         entity_t *iter = compound->members.entities;
6521         for (; iter != NULL; iter = iter->base.next) {
6522                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6523                         continue;
6524
6525                 if (iter->base.symbol == symbol) {
6526                         return iter;
6527                 } else if (iter->base.symbol == NULL) {
6528                         type_t *type = skip_typeref(iter->declaration.type);
6529                         if (is_type_compound(type)) {
6530                                 entity_t *result
6531                                         = find_compound_entry(type->compound.compound, symbol);
6532                                 if (result != NULL)
6533                                         return result;
6534                         }
6535                         continue;
6536                 }
6537         }
6538
6539         return NULL;
6540 }
6541
6542 static void parse_compound_declarators(compound_t *compound,
6543                 const declaration_specifiers_t *specifiers)
6544 {
6545         while (true) {
6546                 entity_t *entity;
6547
6548                 if (token.type == ':') {
6549                         source_position_t source_position = *HERE;
6550                         next_token();
6551
6552                         type_t *base_type = specifiers->type;
6553                         expression_t *size = parse_constant_expression();
6554
6555                         type_t *type = make_bitfield_type(base_type, size,
6556                                         &source_position, sym_anonymous);
6557
6558                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6559                         entity->base.namespc                       = NAMESPACE_NORMAL;
6560                         entity->base.source_position               = source_position;
6561                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6562                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6563                         entity->declaration.modifiers              = specifiers->modifiers;
6564                         entity->declaration.type                   = type;
6565                         append_entity(&compound->members, entity);
6566                 } else {
6567                         entity = parse_declarator(specifiers,
6568                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6569                         if (entity->kind == ENTITY_TYPEDEF) {
6570                                 errorf(&entity->base.source_position,
6571                                                 "typedef not allowed as compound member");
6572                         } else {
6573                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6574
6575                                 /* make sure we don't define a symbol multiple times */
6576                                 symbol_t *symbol = entity->base.symbol;
6577                                 if (symbol != NULL) {
6578                                         entity_t *prev = find_compound_entry(compound, symbol);
6579                                         if (prev != NULL) {
6580                                                 errorf(&entity->base.source_position,
6581                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6582                                                                 symbol, &prev->base.source_position);
6583                                         }
6584                                 }
6585
6586                                 if (token.type == ':') {
6587                                         source_position_t source_position = *HERE;
6588                                         next_token();
6589                                         expression_t *size = parse_constant_expression();
6590
6591                                         type_t *type          = entity->declaration.type;
6592                                         type_t *bitfield_type = make_bitfield_type(type, size,
6593                                                         &source_position, entity->base.symbol);
6594                                         entity->declaration.type = bitfield_type;
6595                                 } else {
6596                                         type_t *orig_type = entity->declaration.type;
6597                                         type_t *type      = skip_typeref(orig_type);
6598                                         if (is_type_function(type)) {
6599                                                 errorf(&entity->base.source_position,
6600                                                                 "compound member '%Y' must not have function type '%T'",
6601                                                                 entity->base.symbol, orig_type);
6602                                         } else if (is_type_incomplete(type)) {
6603                                                 /* §6.7.2.1:16 flexible array member */
6604                                                 if (!is_type_array(type)       ||
6605                                                                 token.type          != ';' ||
6606                                                                 look_ahead(1)->type != '}') {
6607                                                         errorf(&entity->base.source_position,
6608                                                                         "compound member '%Y' has incomplete type '%T'",
6609                                                                         entity->base.symbol, orig_type);
6610                                                 }
6611                                         }
6612                                 }
6613
6614                                 append_entity(&compound->members, entity);
6615                         }
6616                 }
6617
6618                 if (token.type != ',')
6619                         break;
6620                 next_token();
6621         }
6622         expect(';', end_error);
6623
6624 end_error:
6625         anonymous_entity = NULL;
6626 }
6627
6628 static void parse_compound_type_entries(compound_t *compound)
6629 {
6630         eat('{');
6631         add_anchor_token('}');
6632
6633         while (token.type != '}') {
6634                 if (token.type == T_EOF) {
6635                         errorf(HERE, "EOF while parsing struct");
6636                         break;
6637                 }
6638                 declaration_specifiers_t specifiers;
6639                 memset(&specifiers, 0, sizeof(specifiers));
6640                 parse_declaration_specifiers(&specifiers);
6641
6642                 parse_compound_declarators(compound, &specifiers);
6643         }
6644         rem_anchor_token('}');
6645         next_token();
6646
6647         /* §6.7.2.1:7 */
6648         compound->complete = true;
6649 }
6650
6651 static type_t *parse_typename(void)
6652 {
6653         declaration_specifiers_t specifiers;
6654         memset(&specifiers, 0, sizeof(specifiers));
6655         parse_declaration_specifiers(&specifiers);
6656         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6657                         specifiers.thread_local) {
6658                 /* TODO: improve error message, user does probably not know what a
6659                  * storage class is...
6660                  */
6661                 errorf(HERE, "typename may not have a storage class");
6662         }
6663
6664         type_t *result = parse_abstract_declarator(specifiers.type);
6665
6666         return result;
6667 }
6668
6669
6670
6671
6672 typedef expression_t* (*parse_expression_function)(void);
6673 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6674
6675 typedef struct expression_parser_function_t expression_parser_function_t;
6676 struct expression_parser_function_t {
6677         parse_expression_function        parser;
6678         precedence_t                     infix_precedence;
6679         parse_expression_infix_function  infix_parser;
6680 };
6681
6682 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6683
6684 /**
6685  * Prints an error message if an expression was expected but not read
6686  */
6687 static expression_t *expected_expression_error(void)
6688 {
6689         /* skip the error message if the error token was read */
6690         if (token.type != T_ERROR) {
6691                 errorf(HERE, "expected expression, got token %K", &token);
6692         }
6693         next_token();
6694
6695         return create_invalid_expression();
6696 }
6697
6698 /**
6699  * Parse a string constant.
6700  */
6701 static expression_t *parse_string_const(void)
6702 {
6703         wide_string_t wres;
6704         if (token.type == T_STRING_LITERAL) {
6705                 string_t res = token.v.string;
6706                 next_token();
6707                 while (token.type == T_STRING_LITERAL) {
6708                         res = concat_strings(&res, &token.v.string);
6709                         next_token();
6710                 }
6711                 if (token.type != T_WIDE_STRING_LITERAL) {
6712                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6713                         /* note: that we use type_char_ptr here, which is already the
6714                          * automatic converted type. revert_automatic_type_conversion
6715                          * will construct the array type */
6716                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6717                         cnst->string.value = res;
6718                         return cnst;
6719                 }
6720
6721                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6722         } else {
6723                 wres = token.v.wide_string;
6724         }
6725         next_token();
6726
6727         for (;;) {
6728                 switch (token.type) {
6729                         case T_WIDE_STRING_LITERAL:
6730                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6731                                 break;
6732
6733                         case T_STRING_LITERAL:
6734                                 wres = concat_wide_string_string(&wres, &token.v.string);
6735                                 break;
6736
6737                         default: {
6738                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6739                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6740                                 cnst->wide_string.value = wres;
6741                                 return cnst;
6742                         }
6743                 }
6744                 next_token();
6745         }
6746 }
6747
6748 /**
6749  * Parse a boolean constant.
6750  */
6751 static expression_t *parse_bool_const(bool value)
6752 {
6753         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6754         cnst->base.type          = type_bool;
6755         cnst->conste.v.int_value = value;
6756
6757         next_token();
6758
6759         return cnst;
6760 }
6761
6762 /**
6763  * Parse an integer constant.
6764  */
6765 static expression_t *parse_int_const(void)
6766 {
6767         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6768         cnst->base.type          = token.datatype;
6769         cnst->conste.v.int_value = token.v.intvalue;
6770
6771         next_token();
6772
6773         return cnst;
6774 }
6775
6776 /**
6777  * Parse a character constant.
6778  */
6779 static expression_t *parse_character_constant(void)
6780 {
6781         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6782         cnst->base.type          = token.datatype;
6783         cnst->conste.v.character = token.v.string;
6784
6785         if (cnst->conste.v.character.size != 1) {
6786                 if (!GNU_MODE) {
6787                         errorf(HERE, "more than 1 character in character constant");
6788                 } else if (warning.multichar) {
6789                         warningf(HERE, "multi-character character constant");
6790                 }
6791         }
6792         next_token();
6793
6794         return cnst;
6795 }
6796
6797 /**
6798  * Parse a wide character constant.
6799  */
6800 static expression_t *parse_wide_character_constant(void)
6801 {
6802         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6803         cnst->base.type               = token.datatype;
6804         cnst->conste.v.wide_character = token.v.wide_string;
6805
6806         if (cnst->conste.v.wide_character.size != 1) {
6807                 if (!GNU_MODE) {
6808                         errorf(HERE, "more than 1 character in character constant");
6809                 } else if (warning.multichar) {
6810                         warningf(HERE, "multi-character character constant");
6811                 }
6812         }
6813         next_token();
6814
6815         return cnst;
6816 }
6817
6818 /**
6819  * Parse a float constant.
6820  */
6821 static expression_t *parse_float_const(void)
6822 {
6823         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6824         cnst->base.type            = token.datatype;
6825         cnst->conste.v.float_value = token.v.floatvalue;
6826
6827         next_token();
6828
6829         return cnst;
6830 }
6831
6832 static entity_t *create_implicit_function(symbol_t *symbol,
6833                 const source_position_t *source_position)
6834 {
6835         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6836         ntype->function.return_type            = type_int;
6837         ntype->function.unspecified_parameters = true;
6838         ntype->function.linkage                = LINKAGE_C;
6839         type_t *type                           = identify_new_type(ntype);
6840
6841         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6842         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6843         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6844         entity->declaration.type                   = type;
6845         entity->declaration.implicit               = true;
6846         entity->base.symbol                        = symbol;
6847         entity->base.source_position               = *source_position;
6848
6849         bool strict_prototypes_old = warning.strict_prototypes;
6850         warning.strict_prototypes  = false;
6851         record_entity(entity, false);
6852         warning.strict_prototypes = strict_prototypes_old;
6853
6854         return entity;
6855 }
6856
6857 /**
6858  * Creates a return_type (func)(argument_type) function type if not
6859  * already exists.
6860  */
6861 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6862                                     type_t *argument_type2)
6863 {
6864         function_parameter_t *const parameter2 = allocate_parameter(argument_type2);
6865         function_parameter_t *const parameter1 = allocate_parameter(argument_type1);
6866         parameter1->next = parameter2;
6867
6868         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6869         type->function.return_type = return_type;
6870         type->function.parameters  = parameter1;
6871
6872         return identify_new_type(type);
6873 }
6874
6875 /**
6876  * Creates a return_type (func)(argument_type) function type if not
6877  * already exists.
6878  *
6879  * @param return_type    the return type
6880  * @param argument_type  the argument type
6881  */
6882 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6883 {
6884         function_parameter_t *const parameter = allocate_parameter(argument_type);
6885
6886         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6887         type->function.return_type = return_type;
6888         type->function.parameters  = parameter;
6889
6890         return identify_new_type(type);
6891 }
6892
6893 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6894 {
6895         type_t *res = make_function_1_type(return_type, argument_type);
6896         res->function.variadic = 1;
6897         return res;
6898 }
6899
6900 /**
6901  * Creates a return_type (func)(void) function type if not
6902  * already exists.
6903  *
6904  * @param return_type    the return type
6905  */
6906 static type_t *make_function_0_type(type_t *return_type)
6907 {
6908         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6909         type->function.return_type = return_type;
6910         type->function.parameters  = NULL;
6911
6912         return identify_new_type(type);
6913 }
6914
6915 /**
6916  * Creates a NO_RETURN return_type (func)(void) function type if not
6917  * already exists.
6918  *
6919  * @param return_type    the return type
6920  */
6921 static type_t *make_function_0_type_noreturn(type_t *return_type)
6922 {
6923         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6924         type->function.return_type = return_type;
6925         type->function.parameters  = NULL;
6926         type->function.base.modifiers |= DM_NORETURN;
6927         return type;
6928
6929         return identify_new_type(type);
6930 }
6931
6932 /**
6933  * Performs automatic type cast as described in §6.3.2.1.
6934  *
6935  * @param orig_type  the original type
6936  */
6937 static type_t *automatic_type_conversion(type_t *orig_type)
6938 {
6939         type_t *type = skip_typeref(orig_type);
6940         if (is_type_array(type)) {
6941                 array_type_t *array_type   = &type->array;
6942                 type_t       *element_type = array_type->element_type;
6943                 unsigned      qualifiers   = array_type->base.qualifiers;
6944
6945                 return make_pointer_type(element_type, qualifiers);
6946         }
6947
6948         if (is_type_function(type)) {
6949                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6950         }
6951
6952         return orig_type;
6953 }
6954
6955 /**
6956  * reverts the automatic casts of array to pointer types and function
6957  * to function-pointer types as defined §6.3.2.1
6958  */
6959 type_t *revert_automatic_type_conversion(const expression_t *expression)
6960 {
6961         switch (expression->kind) {
6962                 case EXPR_REFERENCE: {
6963                         entity_t *entity = expression->reference.entity;
6964                         if (is_declaration(entity)) {
6965                                 return entity->declaration.type;
6966                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6967                                 return entity->enum_value.enum_type;
6968                         } else {
6969                                 panic("no declaration or enum in reference");
6970                         }
6971                 }
6972
6973                 case EXPR_SELECT: {
6974                         entity_t *entity = expression->select.compound_entry;
6975                         assert(is_declaration(entity));
6976                         type_t   *type   = entity->declaration.type;
6977                         return get_qualified_type(type,
6978                                         expression->base.type->base.qualifiers);
6979                 }
6980
6981                 case EXPR_UNARY_DEREFERENCE: {
6982                         const expression_t *const value = expression->unary.value;
6983                         type_t             *const type  = skip_typeref(value->base.type);
6984                         if (!is_type_pointer(type))
6985                                 return type_error_type;
6986                         return type->pointer.points_to;
6987                 }
6988
6989                 case EXPR_ARRAY_ACCESS: {
6990                         const expression_t *array_ref = expression->array_access.array_ref;
6991                         type_t             *type_left = skip_typeref(array_ref->base.type);
6992                         if (!is_type_pointer(type_left))
6993                                 return type_error_type;
6994                         return type_left->pointer.points_to;
6995                 }
6996
6997                 case EXPR_STRING_LITERAL: {
6998                         size_t size = expression->string.value.size;
6999                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
7000                 }
7001
7002                 case EXPR_WIDE_STRING_LITERAL: {
7003                         size_t size = expression->wide_string.value.size;
7004                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
7005                 }
7006
7007                 case EXPR_COMPOUND_LITERAL:
7008                         return expression->compound_literal.type;
7009
7010                 default:
7011                         return expression->base.type;
7012         }
7013 }
7014
7015 static expression_t *parse_reference(void)
7016 {
7017         symbol_t *const symbol = token.v.symbol;
7018
7019         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
7020
7021         if (entity == NULL) {
7022                 if (!strict_mode && look_ahead(1)->type == '(') {
7023                         /* an implicitly declared function */
7024                         if (warning.error_implicit_function_declaration) {
7025                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
7026                         } else if (warning.implicit_function_declaration) {
7027                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
7028                         }
7029
7030                         entity = create_implicit_function(symbol, HERE);
7031                 } else {
7032                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7033                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7034                 }
7035         }
7036
7037         type_t *orig_type;
7038
7039         if (is_declaration(entity)) {
7040                 orig_type = entity->declaration.type;
7041         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7042                 orig_type = entity->enum_value.enum_type;
7043         } else if (entity->kind == ENTITY_TYPEDEF) {
7044                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7045                         symbol);
7046                 next_token();
7047                 return create_invalid_expression();
7048         } else {
7049                 panic("expected declaration or enum value in reference");
7050         }
7051
7052         /* we always do the auto-type conversions; the & and sizeof parser contains
7053          * code to revert this! */
7054         type_t *type = automatic_type_conversion(orig_type);
7055
7056         expression_kind_t kind = EXPR_REFERENCE;
7057         if (entity->kind == ENTITY_ENUM_VALUE)
7058                 kind = EXPR_REFERENCE_ENUM_VALUE;
7059
7060         expression_t *expression     = allocate_expression_zero(kind);
7061         expression->reference.entity = entity;
7062         expression->base.type        = type;
7063
7064         /* this declaration is used */
7065         if (is_declaration(entity)) {
7066                 entity->declaration.used = true;
7067         }
7068
7069         if (entity->base.parent_scope != file_scope
7070                 && entity->base.parent_scope->depth < current_function->parameters.depth
7071                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7072                 if (entity->kind == ENTITY_VARIABLE) {
7073                         /* access of a variable from an outer function */
7074                         entity->variable.address_taken = true;
7075                 } else if (entity->kind == ENTITY_PARAMETER) {
7076                         entity->parameter.address_taken = true;
7077                 }
7078                 current_function->need_closure = true;
7079         }
7080
7081         /* check for deprecated functions */
7082         if (warning.deprecated_declarations
7083                 && is_declaration(entity)
7084                 && entity->declaration.modifiers & DM_DEPRECATED) {
7085                 declaration_t *declaration = &entity->declaration;
7086
7087                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7088                         "function" : "variable";
7089
7090                 if (declaration->deprecated_string != NULL) {
7091                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7092                                  prefix, entity->base.symbol, &entity->base.source_position,
7093                                  declaration->deprecated_string);
7094                 } else {
7095                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7096                                  entity->base.symbol, &entity->base.source_position);
7097                 }
7098         }
7099
7100         if (warning.init_self && entity == current_init_decl && !in_type_prop
7101             && entity->kind == ENTITY_VARIABLE) {
7102                 current_init_decl = NULL;
7103                 warningf(HERE, "variable '%#T' is initialized by itself",
7104                          entity->declaration.type, entity->base.symbol);
7105         }
7106
7107         next_token();
7108         return expression;
7109 }
7110
7111 static bool semantic_cast(expression_t *cast)
7112 {
7113         expression_t            *expression      = cast->unary.value;
7114         type_t                  *orig_dest_type  = cast->base.type;
7115         type_t                  *orig_type_right = expression->base.type;
7116         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7117         type_t            const *src_type        = skip_typeref(orig_type_right);
7118         source_position_t const *pos             = &cast->base.source_position;
7119
7120         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7121         if (dst_type == type_void)
7122                 return true;
7123
7124         /* only integer and pointer can be casted to pointer */
7125         if (is_type_pointer(dst_type)  &&
7126             !is_type_pointer(src_type) &&
7127             !is_type_integer(src_type) &&
7128             is_type_valid(src_type)) {
7129                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7130                 return false;
7131         }
7132
7133         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7134                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7135                 return false;
7136         }
7137
7138         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7139                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7140                 return false;
7141         }
7142
7143         if (warning.cast_qual &&
7144             is_type_pointer(src_type) &&
7145             is_type_pointer(dst_type)) {
7146                 type_t *src = skip_typeref(src_type->pointer.points_to);
7147                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7148                 unsigned missing_qualifiers =
7149                         src->base.qualifiers & ~dst->base.qualifiers;
7150                 if (missing_qualifiers != 0) {
7151                         warningf(pos,
7152                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7153                                  missing_qualifiers, orig_type_right);
7154                 }
7155         }
7156         return true;
7157 }
7158
7159 static expression_t *parse_compound_literal(type_t *type)
7160 {
7161         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7162
7163         parse_initializer_env_t env;
7164         env.type             = type;
7165         env.entity           = NULL;
7166         env.must_be_constant = false;
7167         initializer_t *initializer = parse_initializer(&env);
7168         type = env.type;
7169
7170         expression->compound_literal.initializer = initializer;
7171         expression->compound_literal.type        = type;
7172         expression->base.type                    = automatic_type_conversion(type);
7173
7174         return expression;
7175 }
7176
7177 /**
7178  * Parse a cast expression.
7179  */
7180 static expression_t *parse_cast(void)
7181 {
7182         add_anchor_token(')');
7183
7184         source_position_t source_position = token.source_position;
7185
7186         type_t *type = parse_typename();
7187
7188         rem_anchor_token(')');
7189         expect(')', end_error);
7190
7191         if (token.type == '{') {
7192                 return parse_compound_literal(type);
7193         }
7194
7195         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7196         cast->base.source_position = source_position;
7197
7198         expression_t *value = parse_sub_expression(PREC_CAST);
7199         cast->base.type   = type;
7200         cast->unary.value = value;
7201
7202         if (! semantic_cast(cast)) {
7203                 /* TODO: record the error in the AST. else it is impossible to detect it */
7204         }
7205
7206         return cast;
7207 end_error:
7208         return create_invalid_expression();
7209 }
7210
7211 /**
7212  * Parse a statement expression.
7213  */
7214 static expression_t *parse_statement_expression(void)
7215 {
7216         add_anchor_token(')');
7217
7218         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7219
7220         statement_t *statement          = parse_compound_statement(true);
7221         statement->compound.stmt_expr   = true;
7222         expression->statement.statement = statement;
7223
7224         /* find last statement and use its type */
7225         type_t *type = type_void;
7226         const statement_t *stmt = statement->compound.statements;
7227         if (stmt != NULL) {
7228                 while (stmt->base.next != NULL)
7229                         stmt = stmt->base.next;
7230
7231                 if (stmt->kind == STATEMENT_EXPRESSION) {
7232                         type = stmt->expression.expression->base.type;
7233                 }
7234         } else if (warning.other) {
7235                 warningf(&expression->base.source_position, "empty statement expression ({})");
7236         }
7237         expression->base.type = type;
7238
7239         rem_anchor_token(')');
7240         expect(')', end_error);
7241
7242 end_error:
7243         return expression;
7244 }
7245
7246 /**
7247  * Parse a parenthesized expression.
7248  */
7249 static expression_t *parse_parenthesized_expression(void)
7250 {
7251         eat('(');
7252
7253         switch (token.type) {
7254         case '{':
7255                 /* gcc extension: a statement expression */
7256                 return parse_statement_expression();
7257
7258         TYPE_QUALIFIERS
7259         TYPE_SPECIFIERS
7260                 return parse_cast();
7261         case T_IDENTIFIER:
7262                 if (is_typedef_symbol(token.v.symbol)) {
7263                         return parse_cast();
7264                 }
7265         }
7266
7267         add_anchor_token(')');
7268         expression_t *result = parse_expression();
7269         result->base.parenthesized = true;
7270         rem_anchor_token(')');
7271         expect(')', end_error);
7272
7273 end_error:
7274         return result;
7275 }
7276
7277 static expression_t *parse_function_keyword(void)
7278 {
7279         /* TODO */
7280
7281         if (current_function == NULL) {
7282                 errorf(HERE, "'__func__' used outside of a function");
7283         }
7284
7285         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7286         expression->base.type     = type_char_ptr;
7287         expression->funcname.kind = FUNCNAME_FUNCTION;
7288
7289         next_token();
7290
7291         return expression;
7292 }
7293
7294 static expression_t *parse_pretty_function_keyword(void)
7295 {
7296         if (current_function == NULL) {
7297                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7298         }
7299
7300         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7301         expression->base.type     = type_char_ptr;
7302         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7303
7304         eat(T___PRETTY_FUNCTION__);
7305
7306         return expression;
7307 }
7308
7309 static expression_t *parse_funcsig_keyword(void)
7310 {
7311         if (current_function == NULL) {
7312                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7313         }
7314
7315         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7316         expression->base.type     = type_char_ptr;
7317         expression->funcname.kind = FUNCNAME_FUNCSIG;
7318
7319         eat(T___FUNCSIG__);
7320
7321         return expression;
7322 }
7323
7324 static expression_t *parse_funcdname_keyword(void)
7325 {
7326         if (current_function == NULL) {
7327                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7328         }
7329
7330         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7331         expression->base.type     = type_char_ptr;
7332         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7333
7334         eat(T___FUNCDNAME__);
7335
7336         return expression;
7337 }
7338
7339 static designator_t *parse_designator(void)
7340 {
7341         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7342         result->source_position = *HERE;
7343
7344         if (token.type != T_IDENTIFIER) {
7345                 parse_error_expected("while parsing member designator",
7346                                      T_IDENTIFIER, NULL);
7347                 return NULL;
7348         }
7349         result->symbol = token.v.symbol;
7350         next_token();
7351
7352         designator_t *last_designator = result;
7353         while (true) {
7354                 if (token.type == '.') {
7355                         next_token();
7356                         if (token.type != T_IDENTIFIER) {
7357                                 parse_error_expected("while parsing member designator",
7358                                                      T_IDENTIFIER, NULL);
7359                                 return NULL;
7360                         }
7361                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7362                         designator->source_position = *HERE;
7363                         designator->symbol          = token.v.symbol;
7364                         next_token();
7365
7366                         last_designator->next = designator;
7367                         last_designator       = designator;
7368                         continue;
7369                 }
7370                 if (token.type == '[') {
7371                         next_token();
7372                         add_anchor_token(']');
7373                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7374                         designator->source_position = *HERE;
7375                         designator->array_index     = parse_expression();
7376                         rem_anchor_token(']');
7377                         expect(']', end_error);
7378                         if (designator->array_index == NULL) {
7379                                 return NULL;
7380                         }
7381
7382                         last_designator->next = designator;
7383                         last_designator       = designator;
7384                         continue;
7385                 }
7386                 break;
7387         }
7388
7389         return result;
7390 end_error:
7391         return NULL;
7392 }
7393
7394 /**
7395  * Parse the __builtin_offsetof() expression.
7396  */
7397 static expression_t *parse_offsetof(void)
7398 {
7399         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7400         expression->base.type    = type_size_t;
7401
7402         eat(T___builtin_offsetof);
7403
7404         expect('(', end_error);
7405         add_anchor_token(',');
7406         type_t *type = parse_typename();
7407         rem_anchor_token(',');
7408         expect(',', end_error);
7409         add_anchor_token(')');
7410         designator_t *designator = parse_designator();
7411         rem_anchor_token(')');
7412         expect(')', end_error);
7413
7414         expression->offsetofe.type       = type;
7415         expression->offsetofe.designator = designator;
7416
7417         type_path_t path;
7418         memset(&path, 0, sizeof(path));
7419         path.top_type = type;
7420         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7421
7422         descend_into_subtype(&path);
7423
7424         if (!walk_designator(&path, designator, true)) {
7425                 return create_invalid_expression();
7426         }
7427
7428         DEL_ARR_F(path.path);
7429
7430         return expression;
7431 end_error:
7432         return create_invalid_expression();
7433 }
7434
7435 /**
7436  * Parses a _builtin_va_start() expression.
7437  */
7438 static expression_t *parse_va_start(void)
7439 {
7440         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7441
7442         eat(T___builtin_va_start);
7443
7444         expect('(', end_error);
7445         add_anchor_token(',');
7446         expression->va_starte.ap = parse_assignment_expression();
7447         rem_anchor_token(',');
7448         expect(',', end_error);
7449         expression_t *const expr = parse_assignment_expression();
7450         if (expr->kind == EXPR_REFERENCE) {
7451                 entity_t *const entity = expr->reference.entity;
7452                 if (entity->base.parent_scope != &current_function->parameters
7453                                 || entity->base.next != NULL
7454                                 || entity->kind != ENTITY_PARAMETER) {
7455                         errorf(&expr->base.source_position,
7456                                "second argument of 'va_start' must be last parameter of the current function");
7457                 } else {
7458                         expression->va_starte.parameter = &entity->variable;
7459                 }
7460                 expect(')', end_error);
7461                 return expression;
7462         }
7463         expect(')', end_error);
7464 end_error:
7465         return create_invalid_expression();
7466 }
7467
7468 /**
7469  * Parses a __builtin_va_arg() expression.
7470  */
7471 static expression_t *parse_va_arg(void)
7472 {
7473         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7474
7475         eat(T___builtin_va_arg);
7476
7477         expect('(', end_error);
7478         call_argument_t ap;
7479         ap.expression = parse_assignment_expression();
7480         expression->va_arge.ap = ap.expression;
7481         check_call_argument(type_valist, &ap, 1);
7482
7483         expect(',', end_error);
7484         expression->base.type = parse_typename();
7485         expect(')', end_error);
7486
7487         return expression;
7488 end_error:
7489         return create_invalid_expression();
7490 }
7491
7492 /**
7493  * Parses a __builtin_va_copy() expression.
7494  */
7495 static expression_t *parse_va_copy(void)
7496 {
7497         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
7498
7499         eat(T___builtin_va_copy);
7500
7501         expect('(', end_error);
7502         expression_t *dst = parse_assignment_expression();
7503         assign_error_t error = semantic_assign(type_valist, dst);
7504         report_assign_error(error, type_valist, dst, "call argument 1",
7505                             &dst->base.source_position);
7506         expression->va_copye.dst = dst;
7507
7508         expect(',', end_error);
7509
7510         call_argument_t src;
7511         src.expression = parse_assignment_expression();
7512         check_call_argument(type_valist, &src, 2);
7513         expression->va_copye.src = src.expression;
7514         expect(')', end_error);
7515
7516         return expression;
7517 end_error:
7518         return create_invalid_expression();
7519 }
7520
7521 /**
7522  * Parses a __builtin_constant_p() expression.
7523  */
7524 static expression_t *parse_builtin_constant(void)
7525 {
7526         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7527
7528         eat(T___builtin_constant_p);
7529
7530         expect('(', end_error);
7531         add_anchor_token(')');
7532         expression->builtin_constant.value = parse_assignment_expression();
7533         rem_anchor_token(')');
7534         expect(')', end_error);
7535         expression->base.type = type_int;
7536
7537         return expression;
7538 end_error:
7539         return create_invalid_expression();
7540 }
7541
7542 /**
7543  * Parses a __builtin_types_compatible_p() expression.
7544  */
7545 static expression_t *parse_builtin_types_compatible(void)
7546 {
7547         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
7548
7549         eat(T___builtin_types_compatible_p);
7550
7551         expect('(', end_error);
7552         add_anchor_token(')');
7553         add_anchor_token(',');
7554         expression->builtin_types_compatible.left = parse_typename();
7555         rem_anchor_token(',');
7556         expect(',', end_error);
7557         expression->builtin_types_compatible.right = parse_typename();
7558         rem_anchor_token(')');
7559         expect(')', end_error);
7560         expression->base.type = type_int;
7561
7562         return expression;
7563 end_error:
7564         return create_invalid_expression();
7565 }
7566
7567 /**
7568  * Parses a __builtin_is_*() compare expression.
7569  */
7570 static expression_t *parse_compare_builtin(void)
7571 {
7572         expression_t *expression;
7573
7574         switch (token.type) {
7575         case T___builtin_isgreater:
7576                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7577                 break;
7578         case T___builtin_isgreaterequal:
7579                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7580                 break;
7581         case T___builtin_isless:
7582                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7583                 break;
7584         case T___builtin_islessequal:
7585                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7586                 break;
7587         case T___builtin_islessgreater:
7588                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7589                 break;
7590         case T___builtin_isunordered:
7591                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7592                 break;
7593         default:
7594                 internal_errorf(HERE, "invalid compare builtin found");
7595         }
7596         expression->base.source_position = *HERE;
7597         next_token();
7598
7599         expect('(', end_error);
7600         expression->binary.left = parse_assignment_expression();
7601         expect(',', end_error);
7602         expression->binary.right = parse_assignment_expression();
7603         expect(')', end_error);
7604
7605         type_t *const orig_type_left  = expression->binary.left->base.type;
7606         type_t *const orig_type_right = expression->binary.right->base.type;
7607
7608         type_t *const type_left  = skip_typeref(orig_type_left);
7609         type_t *const type_right = skip_typeref(orig_type_right);
7610         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7611                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7612                         type_error_incompatible("invalid operands in comparison",
7613                                 &expression->base.source_position, orig_type_left, orig_type_right);
7614                 }
7615         } else {
7616                 semantic_comparison(&expression->binary);
7617         }
7618
7619         return expression;
7620 end_error:
7621         return create_invalid_expression();
7622 }
7623
7624 #if 0
7625 /**
7626  * Parses a __builtin_expect(, end_error) expression.
7627  */
7628 static expression_t *parse_builtin_expect(void, end_error)
7629 {
7630         expression_t *expression
7631                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7632
7633         eat(T___builtin_expect);
7634
7635         expect('(', end_error);
7636         expression->binary.left = parse_assignment_expression();
7637         expect(',', end_error);
7638         expression->binary.right = parse_constant_expression();
7639         expect(')', end_error);
7640
7641         expression->base.type = expression->binary.left->base.type;
7642
7643         return expression;
7644 end_error:
7645         return create_invalid_expression();
7646 }
7647 #endif
7648
7649 /**
7650  * Parses a MS assume() expression.
7651  */
7652 static expression_t *parse_assume(void)
7653 {
7654         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7655
7656         eat(T__assume);
7657
7658         expect('(', end_error);
7659         add_anchor_token(')');
7660         expression->unary.value = parse_assignment_expression();
7661         rem_anchor_token(')');
7662         expect(')', end_error);
7663
7664         expression->base.type = type_void;
7665         return expression;
7666 end_error:
7667         return create_invalid_expression();
7668 }
7669
7670 /**
7671  * Return the declaration for a given label symbol or create a new one.
7672  *
7673  * @param symbol  the symbol of the label
7674  */
7675 static label_t *get_label(symbol_t *symbol)
7676 {
7677         entity_t *label;
7678         assert(current_function != NULL);
7679
7680         label = get_entity(symbol, NAMESPACE_LABEL);
7681         /* if we found a local label, we already created the declaration */
7682         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7683                 if (label->base.parent_scope != current_scope) {
7684                         assert(label->base.parent_scope->depth < current_scope->depth);
7685                         current_function->goto_to_outer = true;
7686                 }
7687                 return &label->label;
7688         }
7689
7690         label = get_entity(symbol, NAMESPACE_LABEL);
7691         /* if we found a label in the same function, then we already created the
7692          * declaration */
7693         if (label != NULL
7694                         && label->base.parent_scope == &current_function->parameters) {
7695                 return &label->label;
7696         }
7697
7698         /* otherwise we need to create a new one */
7699         label               = allocate_entity_zero(ENTITY_LABEL);
7700         label->base.namespc = NAMESPACE_LABEL;
7701         label->base.symbol  = symbol;
7702
7703         label_push(label);
7704
7705         return &label->label;
7706 }
7707
7708 /**
7709  * Parses a GNU && label address expression.
7710  */
7711 static expression_t *parse_label_address(void)
7712 {
7713         source_position_t source_position = token.source_position;
7714         eat(T_ANDAND);
7715         if (token.type != T_IDENTIFIER) {
7716                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7717                 goto end_error;
7718         }
7719         symbol_t *symbol = token.v.symbol;
7720         next_token();
7721
7722         label_t *label       = get_label(symbol);
7723         label->used          = true;
7724         label->address_taken = true;
7725
7726         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7727         expression->base.source_position = source_position;
7728
7729         /* label address is threaten as a void pointer */
7730         expression->base.type           = type_void_ptr;
7731         expression->label_address.label = label;
7732         return expression;
7733 end_error:
7734         return create_invalid_expression();
7735 }
7736
7737 /**
7738  * Parse a microsoft __noop expression.
7739  */
7740 static expression_t *parse_noop_expression(void)
7741 {
7742         /* the result is a (int)0 */
7743         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7744         cnst->base.type            = type_int;
7745         cnst->conste.v.int_value   = 0;
7746         cnst->conste.is_ms_noop    = true;
7747
7748         eat(T___noop);
7749
7750         if (token.type == '(') {
7751                 /* parse arguments */
7752                 eat('(');
7753                 add_anchor_token(')');
7754                 add_anchor_token(',');
7755
7756                 if (token.type != ')') {
7757                         while (true) {
7758                                 (void)parse_assignment_expression();
7759                                 if (token.type != ',')
7760                                         break;
7761                                 next_token();
7762                         }
7763                 }
7764         }
7765         rem_anchor_token(',');
7766         rem_anchor_token(')');
7767         expect(')', end_error);
7768
7769 end_error:
7770         return cnst;
7771 }
7772
7773 /**
7774  * Parses a primary expression.
7775  */
7776 static expression_t *parse_primary_expression(void)
7777 {
7778         switch (token.type) {
7779                 case T_false:                        return parse_bool_const(false);
7780                 case T_true:                         return parse_bool_const(true);
7781                 case T_INTEGER:                      return parse_int_const();
7782                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7783                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7784                 case T_FLOATINGPOINT:                return parse_float_const();
7785                 case T_STRING_LITERAL:
7786                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7787                 case T_IDENTIFIER:                   return parse_reference();
7788                 case T___FUNCTION__:
7789                 case T___func__:                     return parse_function_keyword();
7790                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7791                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7792                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7793                 case T___builtin_offsetof:           return parse_offsetof();
7794                 case T___builtin_va_start:           return parse_va_start();
7795                 case T___builtin_va_arg:             return parse_va_arg();
7796                 case T___builtin_va_copy:            return parse_va_copy();
7797                 case T___builtin_isgreater:
7798                 case T___builtin_isgreaterequal:
7799                 case T___builtin_isless:
7800                 case T___builtin_islessequal:
7801                 case T___builtin_islessgreater:
7802                 case T___builtin_isunordered:        return parse_compare_builtin();
7803                 case T___builtin_constant_p:         return parse_builtin_constant();
7804                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7805                 case T__assume:                      return parse_assume();
7806                 case T_ANDAND:
7807                         if (GNU_MODE)
7808                                 return parse_label_address();
7809                         break;
7810
7811                 case '(':                            return parse_parenthesized_expression();
7812                 case T___noop:                       return parse_noop_expression();
7813         }
7814
7815         errorf(HERE, "unexpected token %K, expected an expression", &token);
7816         return create_invalid_expression();
7817 }
7818
7819 /**
7820  * Check if the expression has the character type and issue a warning then.
7821  */
7822 static void check_for_char_index_type(const expression_t *expression)
7823 {
7824         type_t       *const type      = expression->base.type;
7825         const type_t *const base_type = skip_typeref(type);
7826
7827         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7828                         warning.char_subscripts) {
7829                 warningf(&expression->base.source_position,
7830                          "array subscript has type '%T'", type);
7831         }
7832 }
7833
7834 static expression_t *parse_array_expression(expression_t *left)
7835 {
7836         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7837
7838         eat('[');
7839         add_anchor_token(']');
7840
7841         expression_t *inside = parse_expression();
7842
7843         type_t *const orig_type_left   = left->base.type;
7844         type_t *const orig_type_inside = inside->base.type;
7845
7846         type_t *const type_left   = skip_typeref(orig_type_left);
7847         type_t *const type_inside = skip_typeref(orig_type_inside);
7848
7849         type_t                    *return_type;
7850         array_access_expression_t *array_access = &expression->array_access;
7851         if (is_type_pointer(type_left)) {
7852                 return_type             = type_left->pointer.points_to;
7853                 array_access->array_ref = left;
7854                 array_access->index     = inside;
7855                 check_for_char_index_type(inside);
7856         } else if (is_type_pointer(type_inside)) {
7857                 return_type             = type_inside->pointer.points_to;
7858                 array_access->array_ref = inside;
7859                 array_access->index     = left;
7860                 array_access->flipped   = true;
7861                 check_for_char_index_type(left);
7862         } else {
7863                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7864                         errorf(HERE,
7865                                 "array access on object with non-pointer types '%T', '%T'",
7866                                 orig_type_left, orig_type_inside);
7867                 }
7868                 return_type             = type_error_type;
7869                 array_access->array_ref = left;
7870                 array_access->index     = inside;
7871         }
7872
7873         expression->base.type = automatic_type_conversion(return_type);
7874
7875         rem_anchor_token(']');
7876         expect(']', end_error);
7877 end_error:
7878         return expression;
7879 }
7880
7881 static expression_t *parse_typeprop(expression_kind_t const kind)
7882 {
7883         expression_t  *tp_expression = allocate_expression_zero(kind);
7884         tp_expression->base.type     = type_size_t;
7885
7886         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7887
7888         /* we only refer to a type property, mark this case */
7889         bool old     = in_type_prop;
7890         in_type_prop = true;
7891
7892         type_t       *orig_type;
7893         expression_t *expression;
7894         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7895                 next_token();
7896                 add_anchor_token(')');
7897                 orig_type = parse_typename();
7898                 rem_anchor_token(')');
7899                 expect(')', end_error);
7900
7901                 if (token.type == '{') {
7902                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7903                          * starting with a compound literal */
7904                         expression = parse_compound_literal(orig_type);
7905                         goto typeprop_expression;
7906                 }
7907         } else {
7908                 expression = parse_sub_expression(PREC_UNARY);
7909
7910 typeprop_expression:
7911                 tp_expression->typeprop.tp_expression = expression;
7912
7913                 orig_type = revert_automatic_type_conversion(expression);
7914                 expression->base.type = orig_type;
7915         }
7916
7917         tp_expression->typeprop.type   = orig_type;
7918         type_t const* const type       = skip_typeref(orig_type);
7919         char   const* const wrong_type =
7920                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7921                 is_type_incomplete(type)                           ? "incomplete"          :
7922                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7923                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7924                 NULL;
7925         if (wrong_type != NULL) {
7926                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7927                 errorf(&tp_expression->base.source_position,
7928                                 "operand of %s expression must not be of %s type '%T'",
7929                                 what, wrong_type, orig_type);
7930         }
7931
7932 end_error:
7933         in_type_prop = old;
7934         return tp_expression;
7935 }
7936
7937 static expression_t *parse_sizeof(void)
7938 {
7939         return parse_typeprop(EXPR_SIZEOF);
7940 }
7941
7942 static expression_t *parse_alignof(void)
7943 {
7944         return parse_typeprop(EXPR_ALIGNOF);
7945 }
7946
7947 static expression_t *parse_select_expression(expression_t *compound)
7948 {
7949         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7950         select->select.compound = compound;
7951
7952         assert(token.type == '.' || token.type == T_MINUSGREATER);
7953         bool is_pointer = (token.type == T_MINUSGREATER);
7954         next_token();
7955
7956         if (token.type != T_IDENTIFIER) {
7957                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7958                 return select;
7959         }
7960         symbol_t *symbol = token.v.symbol;
7961         next_token();
7962
7963         type_t *const orig_type = compound->base.type;
7964         type_t *const type      = skip_typeref(orig_type);
7965
7966         type_t *type_left;
7967         bool    saw_error = false;
7968         if (is_type_pointer(type)) {
7969                 if (!is_pointer) {
7970                         errorf(HERE,
7971                                "request for member '%Y' in something not a struct or union, but '%T'",
7972                                symbol, orig_type);
7973                         saw_error = true;
7974                 }
7975                 type_left = skip_typeref(type->pointer.points_to);
7976         } else {
7977                 if (is_pointer && is_type_valid(type)) {
7978                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7979                         saw_error = true;
7980                 }
7981                 type_left = type;
7982         }
7983
7984         entity_t *entry;
7985         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7986             type_left->kind == TYPE_COMPOUND_UNION) {
7987                 compound_t *compound = type_left->compound.compound;
7988
7989                 if (!compound->complete) {
7990                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7991                                symbol, type_left);
7992                         goto create_error_entry;
7993                 }
7994
7995                 entry = find_compound_entry(compound, symbol);
7996                 if (entry == NULL) {
7997                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7998                         goto create_error_entry;
7999                 }
8000         } else {
8001                 if (is_type_valid(type_left) && !saw_error) {
8002                         errorf(HERE,
8003                                "request for member '%Y' in something not a struct or union, but '%T'",
8004                                symbol, type_left);
8005                 }
8006 create_error_entry:
8007                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
8008         }
8009
8010         assert(is_declaration(entry));
8011         select->select.compound_entry = entry;
8012
8013         type_t *entry_type = entry->declaration.type;
8014         type_t *res_type
8015                 = get_qualified_type(entry_type, type_left->base.qualifiers);
8016
8017         /* we always do the auto-type conversions; the & and sizeof parser contains
8018          * code to revert this! */
8019         select->base.type = automatic_type_conversion(res_type);
8020
8021         type_t *skipped = skip_typeref(res_type);
8022         if (skipped->kind == TYPE_BITFIELD) {
8023                 select->base.type = skipped->bitfield.base_type;
8024         }
8025
8026         return select;
8027 }
8028
8029 static void check_call_argument(type_t          *expected_type,
8030                                 call_argument_t *argument, unsigned pos)
8031 {
8032         type_t         *expected_type_skip = skip_typeref(expected_type);
8033         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
8034         expression_t   *arg_expr           = argument->expression;
8035         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
8036
8037         /* handle transparent union gnu extension */
8038         if (is_type_union(expected_type_skip)
8039                         && (expected_type_skip->base.modifiers
8040                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
8041                 compound_t *union_decl  = expected_type_skip->compound.compound;
8042                 type_t     *best_type   = NULL;
8043                 entity_t   *entry       = union_decl->members.entities;
8044                 for ( ; entry != NULL; entry = entry->base.next) {
8045                         assert(is_declaration(entry));
8046                         type_t *decl_type = entry->declaration.type;
8047                         error = semantic_assign(decl_type, arg_expr);
8048                         if (error == ASSIGN_ERROR_INCOMPATIBLE
8049                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
8050                                 continue;
8051
8052                         if (error == ASSIGN_SUCCESS) {
8053                                 best_type = decl_type;
8054                         } else if (best_type == NULL) {
8055                                 best_type = decl_type;
8056                         }
8057                 }
8058
8059                 if (best_type != NULL) {
8060                         expected_type = best_type;
8061                 }
8062         }
8063
8064         error                = semantic_assign(expected_type, arg_expr);
8065         argument->expression = create_implicit_cast(arg_expr, expected_type);
8066
8067         if (error != ASSIGN_SUCCESS) {
8068                 /* report exact scope in error messages (like "in argument 3") */
8069                 char buf[64];
8070                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8071                 report_assign_error(error, expected_type, arg_expr,     buf,
8072                                                         &arg_expr->base.source_position);
8073         } else if (warning.traditional || warning.conversion) {
8074                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8075                 if (!types_compatible(expected_type_skip, promoted_type) &&
8076                     !types_compatible(expected_type_skip, type_void_ptr) &&
8077                     !types_compatible(type_void_ptr,      promoted_type)) {
8078                         /* Deliberately show the skipped types in this warning */
8079                         warningf(&arg_expr->base.source_position,
8080                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8081                                 pos, expected_type_skip, promoted_type);
8082                 }
8083         }
8084 }
8085
8086 /**
8087  * Handle the semantic restrictions of builtin calls
8088  */
8089 static void handle_builtin_argument_restrictions(call_expression_t *call) {
8090         switch (call->function->reference.entity->function.btk) {
8091                 case bk_gnu_builtin_return_address:
8092                 case bk_gnu_builtin_frame_address: {
8093                         /* argument must be constant */
8094                         call_argument_t *argument = call->arguments;
8095
8096                         if (! is_constant_expression(argument->expression)) {
8097                                 errorf(&call->base.source_position,
8098                                        "argument of '%Y' must be a constant expression",
8099                                        call->function->reference.entity->base.symbol);
8100                         }
8101                         break;
8102                 }
8103                 case bk_gnu_builtin_prefetch: {
8104                         /* second and third argument must be constant if existent */
8105                         call_argument_t *rw = call->arguments->next;
8106                         call_argument_t *locality = NULL;
8107
8108                         if (rw != NULL) {
8109                                 if (! is_constant_expression(rw->expression)) {
8110                                         errorf(&call->base.source_position,
8111                                                "second argument of '%Y' must be a constant expression",
8112                                                call->function->reference.entity->base.symbol);
8113                                 }
8114                                 locality = rw->next;
8115                         }
8116                         if (locality != NULL) {
8117                                 if (! is_constant_expression(locality->expression)) {
8118                                         errorf(&call->base.source_position,
8119                                                "third argument of '%Y' must be a constant expression",
8120                                                call->function->reference.entity->base.symbol);
8121                                 }
8122                                 locality = rw->next;
8123                         }
8124                         break;
8125                 }
8126                 default:
8127                         break;
8128         }
8129 }
8130
8131 /**
8132  * Parse a call expression, ie. expression '( ... )'.
8133  *
8134  * @param expression  the function address
8135  */
8136 static expression_t *parse_call_expression(expression_t *expression)
8137 {
8138         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8139         call_expression_t *call   = &result->call;
8140         call->function            = expression;
8141
8142         type_t *const orig_type = expression->base.type;
8143         type_t *const type      = skip_typeref(orig_type);
8144
8145         function_type_t *function_type = NULL;
8146         if (is_type_pointer(type)) {
8147                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8148
8149                 if (is_type_function(to_type)) {
8150                         function_type   = &to_type->function;
8151                         call->base.type = function_type->return_type;
8152                 }
8153         }
8154
8155         if (function_type == NULL && is_type_valid(type)) {
8156                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8157         }
8158
8159         /* parse arguments */
8160         eat('(');
8161         add_anchor_token(')');
8162         add_anchor_token(',');
8163
8164         if (token.type != ')') {
8165                 call_argument_t **anchor = &call->arguments;
8166                 for (;;) {
8167                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
8168                         argument->expression = parse_assignment_expression();
8169
8170                         *anchor = argument;
8171                         anchor  = &argument->next;
8172
8173                         if (token.type != ',')
8174                                 break;
8175                         next_token();
8176                 }
8177         }
8178         rem_anchor_token(',');
8179         rem_anchor_token(')');
8180         expect(')', end_error);
8181
8182         if (function_type == NULL)
8183                 return result;
8184
8185         function_parameter_t *parameter = function_type->parameters;
8186         call_argument_t      *argument  = call->arguments;
8187         if (!function_type->unspecified_parameters) {
8188                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8189                                 parameter = parameter->next, argument = argument->next) {
8190                         check_call_argument(parameter->type, argument, ++pos);
8191                 }
8192
8193                 if (parameter != NULL) {
8194                         errorf(HERE, "too few arguments to function '%E'", expression);
8195                 } else if (argument != NULL && !function_type->variadic) {
8196                         errorf(HERE, "too many arguments to function '%E'", expression);
8197                 }
8198         }
8199
8200         /* do default promotion */
8201         for (; argument != NULL; argument = argument->next) {
8202                 type_t *type = argument->expression->base.type;
8203
8204                 type = get_default_promoted_type(type);
8205
8206                 argument->expression
8207                         = create_implicit_cast(argument->expression, type);
8208         }
8209
8210         check_format(&result->call);
8211
8212         if (warning.aggregate_return &&
8213             is_type_compound(skip_typeref(function_type->return_type))) {
8214                 warningf(&result->base.source_position,
8215                          "function call has aggregate value");
8216         }
8217
8218         if (call->function->kind == EXPR_REFERENCE) {
8219                 reference_expression_t *reference = &call->function->reference;
8220                 if (reference->entity->kind == ENTITY_FUNCTION &&
8221                     reference->entity->function.btk != bk_none)
8222                         handle_builtin_argument_restrictions(call);
8223         }
8224
8225 end_error:
8226         return result;
8227 }
8228
8229 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8230
8231 static bool same_compound_type(const type_t *type1, const type_t *type2)
8232 {
8233         return
8234                 is_type_compound(type1) &&
8235                 type1->kind == type2->kind &&
8236                 type1->compound.compound == type2->compound.compound;
8237 }
8238
8239 static expression_t const *get_reference_address(expression_t const *expr)
8240 {
8241         bool regular_take_address = true;
8242         for (;;) {
8243                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8244                         expr = expr->unary.value;
8245                 } else {
8246                         regular_take_address = false;
8247                 }
8248
8249                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8250                         break;
8251
8252                 expr = expr->unary.value;
8253         }
8254
8255         if (expr->kind != EXPR_REFERENCE)
8256                 return NULL;
8257
8258         /* special case for functions which are automatically converted to a
8259          * pointer to function without an extra TAKE_ADDRESS operation */
8260         if (!regular_take_address &&
8261                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8262                 return NULL;
8263         }
8264
8265         return expr;
8266 }
8267
8268 static void warn_reference_address_as_bool(expression_t const* expr)
8269 {
8270         if (!warning.address)
8271                 return;
8272
8273         expr = get_reference_address(expr);
8274         if (expr != NULL) {
8275                 warningf(&expr->base.source_position,
8276                          "the address of '%Y' will always evaluate as 'true'",
8277                          expr->reference.entity->base.symbol);
8278         }
8279 }
8280
8281 static void warn_assignment_in_condition(const expression_t *const expr)
8282 {
8283         if (!warning.parentheses)
8284                 return;
8285         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8286                 return;
8287         if (expr->base.parenthesized)
8288                 return;
8289         warningf(&expr->base.source_position,
8290                         "suggest parentheses around assignment used as truth value");
8291 }
8292
8293 static void semantic_condition(expression_t const *const expr,
8294                                char const *const context)
8295 {
8296         type_t *const type = skip_typeref(expr->base.type);
8297         if (is_type_scalar(type)) {
8298                 warn_reference_address_as_bool(expr);
8299                 warn_assignment_in_condition(expr);
8300         } else if (is_type_valid(type)) {
8301                 errorf(&expr->base.source_position,
8302                                 "%s must have scalar type", context);
8303         }
8304 }
8305
8306 /**
8307  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8308  *
8309  * @param expression  the conditional expression
8310  */
8311 static expression_t *parse_conditional_expression(expression_t *expression)
8312 {
8313         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8314
8315         conditional_expression_t *conditional = &result->conditional;
8316         conditional->condition                = expression;
8317
8318         eat('?');
8319         add_anchor_token(':');
8320
8321         /* §6.5.15:2  The first operand shall have scalar type. */
8322         semantic_condition(expression, "condition of conditional operator");
8323
8324         expression_t *true_expression = expression;
8325         bool          gnu_cond = false;
8326         if (GNU_MODE && token.type == ':') {
8327                 gnu_cond = true;
8328         } else {
8329                 true_expression = parse_expression();
8330         }
8331         rem_anchor_token(':');
8332         expect(':', end_error);
8333 end_error:;
8334         expression_t *false_expression =
8335                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8336
8337         type_t *const orig_true_type  = true_expression->base.type;
8338         type_t *const orig_false_type = false_expression->base.type;
8339         type_t *const true_type       = skip_typeref(orig_true_type);
8340         type_t *const false_type      = skip_typeref(orig_false_type);
8341
8342         /* 6.5.15.3 */
8343         type_t *result_type;
8344         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8345                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8346                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8347                 if (true_expression->kind == EXPR_UNARY_THROW) {
8348                         result_type = false_type;
8349                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8350                         result_type = true_type;
8351                 } else {
8352                         if (warning.other && (
8353                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8354                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8355                                         )) {
8356                                 warningf(&conditional->base.source_position,
8357                                                 "ISO C forbids conditional expression with only one void side");
8358                         }
8359                         result_type = type_void;
8360                 }
8361         } else if (is_type_arithmetic(true_type)
8362                    && is_type_arithmetic(false_type)) {
8363                 result_type = semantic_arithmetic(true_type, false_type);
8364
8365                 true_expression  = create_implicit_cast(true_expression, result_type);
8366                 false_expression = create_implicit_cast(false_expression, result_type);
8367
8368                 conditional->true_expression  = true_expression;
8369                 conditional->false_expression = false_expression;
8370                 conditional->base.type        = result_type;
8371         } else if (same_compound_type(true_type, false_type)) {
8372                 /* just take 1 of the 2 types */
8373                 result_type = true_type;
8374         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8375                 type_t *pointer_type;
8376                 type_t *other_type;
8377                 expression_t *other_expression;
8378                 if (is_type_pointer(true_type) &&
8379                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8380                         pointer_type     = true_type;
8381                         other_type       = false_type;
8382                         other_expression = false_expression;
8383                 } else {
8384                         pointer_type     = false_type;
8385                         other_type       = true_type;
8386                         other_expression = true_expression;
8387                 }
8388
8389                 if (is_null_pointer_constant(other_expression)) {
8390                         result_type = pointer_type;
8391                 } else if (is_type_pointer(other_type)) {
8392                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8393                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8394
8395                         type_t *to;
8396                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8397                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8398                                 to = type_void;
8399                         } else if (types_compatible(get_unqualified_type(to1),
8400                                                     get_unqualified_type(to2))) {
8401                                 to = to1;
8402                         } else {
8403                                 if (warning.other) {
8404                                         warningf(&conditional->base.source_position,
8405                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8406                                                         true_type, false_type);
8407                                 }
8408                                 to = type_void;
8409                         }
8410
8411                         type_t *const type =
8412                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8413                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8414                 } else if (is_type_integer(other_type)) {
8415                         if (warning.other) {
8416                                 warningf(&conditional->base.source_position,
8417                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8418                         }
8419                         result_type = pointer_type;
8420                 } else {
8421                         if (is_type_valid(other_type)) {
8422                                 type_error_incompatible("while parsing conditional",
8423                                                 &expression->base.source_position, true_type, false_type);
8424                         }
8425                         result_type = type_error_type;
8426                 }
8427         } else {
8428                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8429                         type_error_incompatible("while parsing conditional",
8430                                                 &conditional->base.source_position, true_type,
8431                                                 false_type);
8432                 }
8433                 result_type = type_error_type;
8434         }
8435
8436         conditional->true_expression
8437                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8438         conditional->false_expression
8439                 = create_implicit_cast(false_expression, result_type);
8440         conditional->base.type = result_type;
8441         return result;
8442 }
8443
8444 /**
8445  * Parse an extension expression.
8446  */
8447 static expression_t *parse_extension(void)
8448 {
8449         eat(T___extension__);
8450
8451         bool old_gcc_extension   = in_gcc_extension;
8452         in_gcc_extension         = true;
8453         expression_t *expression = parse_sub_expression(PREC_UNARY);
8454         in_gcc_extension         = old_gcc_extension;
8455         return expression;
8456 }
8457
8458 /**
8459  * Parse a __builtin_classify_type() expression.
8460  */
8461 static expression_t *parse_builtin_classify_type(void)
8462 {
8463         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8464         result->base.type    = type_int;
8465
8466         eat(T___builtin_classify_type);
8467
8468         expect('(', end_error);
8469         add_anchor_token(')');
8470         expression_t *expression = parse_expression();
8471         rem_anchor_token(')');
8472         expect(')', end_error);
8473         result->classify_type.type_expression = expression;
8474
8475         return result;
8476 end_error:
8477         return create_invalid_expression();
8478 }
8479
8480 /**
8481  * Parse a delete expression
8482  * ISO/IEC 14882:1998(E) §5.3.5
8483  */
8484 static expression_t *parse_delete(void)
8485 {
8486         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8487         result->base.type          = type_void;
8488
8489         eat(T_delete);
8490
8491         if (token.type == '[') {
8492                 next_token();
8493                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8494                 expect(']', end_error);
8495 end_error:;
8496         }
8497
8498         expression_t *const value = parse_sub_expression(PREC_CAST);
8499         result->unary.value = value;
8500
8501         type_t *const type = skip_typeref(value->base.type);
8502         if (!is_type_pointer(type)) {
8503                 if (is_type_valid(type)) {
8504                         errorf(&value->base.source_position,
8505                                         "operand of delete must have pointer type");
8506                 }
8507         } else if (warning.other &&
8508                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8509                 warningf(&value->base.source_position,
8510                                 "deleting 'void*' is undefined");
8511         }
8512
8513         return result;
8514 }
8515
8516 /**
8517  * Parse a throw expression
8518  * ISO/IEC 14882:1998(E) §15:1
8519  */
8520 static expression_t *parse_throw(void)
8521 {
8522         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8523         result->base.type          = type_void;
8524
8525         eat(T_throw);
8526
8527         expression_t *value = NULL;
8528         switch (token.type) {
8529                 EXPRESSION_START {
8530                         value = parse_assignment_expression();
8531                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8532                         type_t *const orig_type = value->base.type;
8533                         type_t *const type      = skip_typeref(orig_type);
8534                         if (is_type_incomplete(type)) {
8535                                 errorf(&value->base.source_position,
8536                                                 "cannot throw object of incomplete type '%T'", orig_type);
8537                         } else if (is_type_pointer(type)) {
8538                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8539                                 if (is_type_incomplete(points_to) &&
8540                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8541                                         errorf(&value->base.source_position,
8542                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8543                                 }
8544                         }
8545                 }
8546
8547                 default:
8548                         break;
8549         }
8550         result->unary.value = value;
8551
8552         return result;
8553 }
8554
8555 static bool check_pointer_arithmetic(const source_position_t *source_position,
8556                                      type_t *pointer_type,
8557                                      type_t *orig_pointer_type)
8558 {
8559         type_t *points_to = pointer_type->pointer.points_to;
8560         points_to = skip_typeref(points_to);
8561
8562         if (is_type_incomplete(points_to)) {
8563                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8564                         errorf(source_position,
8565                                "arithmetic with pointer to incomplete type '%T' not allowed",
8566                                orig_pointer_type);
8567                         return false;
8568                 } else if (warning.pointer_arith) {
8569                         warningf(source_position,
8570                                  "pointer of type '%T' used in arithmetic",
8571                                  orig_pointer_type);
8572                 }
8573         } else if (is_type_function(points_to)) {
8574                 if (!GNU_MODE) {
8575                         errorf(source_position,
8576                                "arithmetic with pointer to function type '%T' not allowed",
8577                                orig_pointer_type);
8578                         return false;
8579                 } else if (warning.pointer_arith) {
8580                         warningf(source_position,
8581                                  "pointer to a function '%T' used in arithmetic",
8582                                  orig_pointer_type);
8583                 }
8584         }
8585         return true;
8586 }
8587
8588 static bool is_lvalue(const expression_t *expression)
8589 {
8590         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8591         switch (expression->kind) {
8592         case EXPR_ARRAY_ACCESS:
8593         case EXPR_COMPOUND_LITERAL:
8594         case EXPR_REFERENCE:
8595         case EXPR_SELECT:
8596         case EXPR_UNARY_DEREFERENCE:
8597                 return true;
8598
8599         default: {
8600           type_t *type = skip_typeref(expression->base.type);
8601           return
8602                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8603                 is_type_reference(type) ||
8604                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8605                  * error before, which maybe prevented properly recognizing it as
8606                  * lvalue. */
8607                 !is_type_valid(type);
8608         }
8609         }
8610 }
8611
8612 static void semantic_incdec(unary_expression_t *expression)
8613 {
8614         type_t *const orig_type = expression->value->base.type;
8615         type_t *const type      = skip_typeref(orig_type);
8616         if (is_type_pointer(type)) {
8617                 if (!check_pointer_arithmetic(&expression->base.source_position,
8618                                               type, orig_type)) {
8619                         return;
8620                 }
8621         } else if (!is_type_real(type) && is_type_valid(type)) {
8622                 /* TODO: improve error message */
8623                 errorf(&expression->base.source_position,
8624                        "operation needs an arithmetic or pointer type");
8625                 return;
8626         }
8627         if (!is_lvalue(expression->value)) {
8628                 /* TODO: improve error message */
8629                 errorf(&expression->base.source_position, "lvalue required as operand");
8630         }
8631         expression->base.type = orig_type;
8632 }
8633
8634 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8635 {
8636         type_t *const orig_type = expression->value->base.type;
8637         type_t *const type      = skip_typeref(orig_type);
8638         if (!is_type_arithmetic(type)) {
8639                 if (is_type_valid(type)) {
8640                         /* TODO: improve error message */
8641                         errorf(&expression->base.source_position,
8642                                 "operation needs an arithmetic type");
8643                 }
8644                 return;
8645         }
8646
8647         expression->base.type = orig_type;
8648 }
8649
8650 static void semantic_unexpr_plus(unary_expression_t *expression)
8651 {
8652         semantic_unexpr_arithmetic(expression);
8653         if (warning.traditional)
8654                 warningf(&expression->base.source_position,
8655                         "traditional C rejects the unary plus operator");
8656 }
8657
8658 static void semantic_not(unary_expression_t *expression)
8659 {
8660         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8661         semantic_condition(expression->value, "operand of !");
8662         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8663 }
8664
8665 static void semantic_unexpr_integer(unary_expression_t *expression)
8666 {
8667         type_t *const orig_type = expression->value->base.type;
8668         type_t *const type      = skip_typeref(orig_type);
8669         if (!is_type_integer(type)) {
8670                 if (is_type_valid(type)) {
8671                         errorf(&expression->base.source_position,
8672                                "operand of ~ must be of integer type");
8673                 }
8674                 return;
8675         }
8676
8677         expression->base.type = orig_type;
8678 }
8679
8680 static void semantic_dereference(unary_expression_t *expression)
8681 {
8682         type_t *const orig_type = expression->value->base.type;
8683         type_t *const type      = skip_typeref(orig_type);
8684         if (!is_type_pointer(type)) {
8685                 if (is_type_valid(type)) {
8686                         errorf(&expression->base.source_position,
8687                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8688                 }
8689                 return;
8690         }
8691
8692         type_t *result_type   = type->pointer.points_to;
8693         result_type           = automatic_type_conversion(result_type);
8694         expression->base.type = result_type;
8695 }
8696
8697 /**
8698  * Record that an address is taken (expression represents an lvalue).
8699  *
8700  * @param expression       the expression
8701  * @param may_be_register  if true, the expression might be an register
8702  */
8703 static void set_address_taken(expression_t *expression, bool may_be_register)
8704 {
8705         if (expression->kind != EXPR_REFERENCE)
8706                 return;
8707
8708         entity_t *const entity = expression->reference.entity;
8709
8710         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8711                 return;
8712
8713         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8714                         && !may_be_register) {
8715                 errorf(&expression->base.source_position,
8716                                 "address of register %s '%Y' requested",
8717                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8718         }
8719
8720         if (entity->kind == ENTITY_VARIABLE) {
8721                 entity->variable.address_taken = true;
8722         } else {
8723                 assert(entity->kind == ENTITY_PARAMETER);
8724                 entity->parameter.address_taken = true;
8725         }
8726 }
8727
8728 /**
8729  * Check the semantic of the address taken expression.
8730  */
8731 static void semantic_take_addr(unary_expression_t *expression)
8732 {
8733         expression_t *value = expression->value;
8734         value->base.type    = revert_automatic_type_conversion(value);
8735
8736         type_t *orig_type = value->base.type;
8737         type_t *type      = skip_typeref(orig_type);
8738         if (!is_type_valid(type))
8739                 return;
8740
8741         /* §6.5.3.2 */
8742         if (!is_lvalue(value)) {
8743                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8744         }
8745         if (type->kind == TYPE_BITFIELD) {
8746                 errorf(&expression->base.source_position,
8747                        "'&' not allowed on object with bitfield type '%T'",
8748                        type);
8749         }
8750
8751         set_address_taken(value, false);
8752
8753         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8754 }
8755
8756 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8757 static expression_t *parse_##unexpression_type(void)                         \
8758 {                                                                            \
8759         expression_t *unary_expression                                           \
8760                 = allocate_expression_zero(unexpression_type);                       \
8761         eat(token_type);                                                         \
8762         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8763                                                                                  \
8764         sfunc(&unary_expression->unary);                                         \
8765                                                                                  \
8766         return unary_expression;                                                 \
8767 }
8768
8769 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8770                                semantic_unexpr_arithmetic)
8771 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8772                                semantic_unexpr_plus)
8773 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8774                                semantic_not)
8775 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8776                                semantic_dereference)
8777 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8778                                semantic_take_addr)
8779 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8780                                semantic_unexpr_integer)
8781 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8782                                semantic_incdec)
8783 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8784                                semantic_incdec)
8785
8786 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8787                                                sfunc)                         \
8788 static expression_t *parse_##unexpression_type(expression_t *left)            \
8789 {                                                                             \
8790         expression_t *unary_expression                                            \
8791                 = allocate_expression_zero(unexpression_type);                        \
8792         eat(token_type);                                                          \
8793         unary_expression->unary.value = left;                                     \
8794                                                                                   \
8795         sfunc(&unary_expression->unary);                                          \
8796                                                                               \
8797         return unary_expression;                                                  \
8798 }
8799
8800 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8801                                        EXPR_UNARY_POSTFIX_INCREMENT,
8802                                        semantic_incdec)
8803 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8804                                        EXPR_UNARY_POSTFIX_DECREMENT,
8805                                        semantic_incdec)
8806
8807 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8808 {
8809         /* TODO: handle complex + imaginary types */
8810
8811         type_left  = get_unqualified_type(type_left);
8812         type_right = get_unqualified_type(type_right);
8813
8814         /* §6.3.1.8 Usual arithmetic conversions */
8815         if (type_left == type_long_double || type_right == type_long_double) {
8816                 return type_long_double;
8817         } else if (type_left == type_double || type_right == type_double) {
8818                 return type_double;
8819         } else if (type_left == type_float || type_right == type_float) {
8820                 return type_float;
8821         }
8822
8823         type_left  = promote_integer(type_left);
8824         type_right = promote_integer(type_right);
8825
8826         if (type_left == type_right)
8827                 return type_left;
8828
8829         bool const signed_left  = is_type_signed(type_left);
8830         bool const signed_right = is_type_signed(type_right);
8831         int const  rank_left    = get_rank(type_left);
8832         int const  rank_right   = get_rank(type_right);
8833
8834         if (signed_left == signed_right)
8835                 return rank_left >= rank_right ? type_left : type_right;
8836
8837         int     s_rank;
8838         int     u_rank;
8839         type_t *s_type;
8840         type_t *u_type;
8841         if (signed_left) {
8842                 s_rank = rank_left;
8843                 s_type = type_left;
8844                 u_rank = rank_right;
8845                 u_type = type_right;
8846         } else {
8847                 s_rank = rank_right;
8848                 s_type = type_right;
8849                 u_rank = rank_left;
8850                 u_type = type_left;
8851         }
8852
8853         if (u_rank >= s_rank)
8854                 return u_type;
8855
8856         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8857          * easier here... */
8858         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8859                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8860                 return s_type;
8861
8862         switch (s_rank) {
8863                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8864                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8865                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8866
8867                 default: panic("invalid atomic type");
8868         }
8869 }
8870
8871 /**
8872  * Check the semantic restrictions for a binary expression.
8873  */
8874 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8875 {
8876         expression_t *const left            = expression->left;
8877         expression_t *const right           = expression->right;
8878         type_t       *const orig_type_left  = left->base.type;
8879         type_t       *const orig_type_right = right->base.type;
8880         type_t       *const type_left       = skip_typeref(orig_type_left);
8881         type_t       *const type_right      = skip_typeref(orig_type_right);
8882
8883         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8884                 /* TODO: improve error message */
8885                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8886                         errorf(&expression->base.source_position,
8887                                "operation needs arithmetic types");
8888                 }
8889                 return;
8890         }
8891
8892         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8893         expression->left      = create_implicit_cast(left, arithmetic_type);
8894         expression->right     = create_implicit_cast(right, arithmetic_type);
8895         expression->base.type = arithmetic_type;
8896 }
8897
8898 static void warn_div_by_zero(binary_expression_t const *const expression)
8899 {
8900         if (!warning.div_by_zero ||
8901             !is_type_integer(expression->base.type))
8902                 return;
8903
8904         expression_t const *const right = expression->right;
8905         /* The type of the right operand can be different for /= */
8906         if (is_type_integer(right->base.type) &&
8907             is_constant_expression(right)     &&
8908             fold_constant(right) == 0) {
8909                 warningf(&expression->base.source_position, "division by zero");
8910         }
8911 }
8912
8913 /**
8914  * Check the semantic restrictions for a div/mod expression.
8915  */
8916 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8917 {
8918         semantic_binexpr_arithmetic(expression);
8919         warn_div_by_zero(expression);
8920 }
8921
8922 static void warn_addsub_in_shift(const expression_t *const expr)
8923 {
8924         if (expr->base.parenthesized)
8925                 return;
8926
8927         char op;
8928         switch (expr->kind) {
8929                 case EXPR_BINARY_ADD: op = '+'; break;
8930                 case EXPR_BINARY_SUB: op = '-'; break;
8931                 default:              return;
8932         }
8933
8934         warningf(&expr->base.source_position,
8935                         "suggest parentheses around '%c' inside shift", op);
8936 }
8937
8938 static void semantic_shift_op(binary_expression_t *expression)
8939 {
8940         expression_t *const left            = expression->left;
8941         expression_t *const right           = expression->right;
8942         type_t       *const orig_type_left  = left->base.type;
8943         type_t       *const orig_type_right = right->base.type;
8944         type_t       *      type_left       = skip_typeref(orig_type_left);
8945         type_t       *      type_right      = skip_typeref(orig_type_right);
8946
8947         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8948                 /* TODO: improve error message */
8949                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8950                         errorf(&expression->base.source_position,
8951                                "operands of shift operation must have integer types");
8952                 }
8953                 return;
8954         }
8955
8956         if (warning.parentheses) {
8957                 warn_addsub_in_shift(left);
8958                 warn_addsub_in_shift(right);
8959         }
8960
8961         type_left  = promote_integer(type_left);
8962         type_right = promote_integer(type_right);
8963
8964         expression->left      = create_implicit_cast(left, type_left);
8965         expression->right     = create_implicit_cast(right, type_right);
8966         expression->base.type = type_left;
8967 }
8968
8969 static void semantic_add(binary_expression_t *expression)
8970 {
8971         expression_t *const left            = expression->left;
8972         expression_t *const right           = expression->right;
8973         type_t       *const orig_type_left  = left->base.type;
8974         type_t       *const orig_type_right = right->base.type;
8975         type_t       *const type_left       = skip_typeref(orig_type_left);
8976         type_t       *const type_right      = skip_typeref(orig_type_right);
8977
8978         /* §6.5.6 */
8979         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8980                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8981                 expression->left  = create_implicit_cast(left, arithmetic_type);
8982                 expression->right = create_implicit_cast(right, arithmetic_type);
8983                 expression->base.type = arithmetic_type;
8984         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8985                 check_pointer_arithmetic(&expression->base.source_position,
8986                                          type_left, orig_type_left);
8987                 expression->base.type = type_left;
8988         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8989                 check_pointer_arithmetic(&expression->base.source_position,
8990                                          type_right, orig_type_right);
8991                 expression->base.type = type_right;
8992         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8993                 errorf(&expression->base.source_position,
8994                        "invalid operands to binary + ('%T', '%T')",
8995                        orig_type_left, orig_type_right);
8996         }
8997 }
8998
8999 static void semantic_sub(binary_expression_t *expression)
9000 {
9001         expression_t            *const left            = expression->left;
9002         expression_t            *const right           = expression->right;
9003         type_t                  *const orig_type_left  = left->base.type;
9004         type_t                  *const orig_type_right = right->base.type;
9005         type_t                  *const type_left       = skip_typeref(orig_type_left);
9006         type_t                  *const type_right      = skip_typeref(orig_type_right);
9007         source_position_t const *const pos             = &expression->base.source_position;
9008
9009         /* §5.6.5 */
9010         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9011                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9012                 expression->left        = create_implicit_cast(left, arithmetic_type);
9013                 expression->right       = create_implicit_cast(right, arithmetic_type);
9014                 expression->base.type =  arithmetic_type;
9015         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9016                 check_pointer_arithmetic(&expression->base.source_position,
9017                                          type_left, orig_type_left);
9018                 expression->base.type = type_left;
9019         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9020                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
9021                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
9022                 if (!types_compatible(unqual_left, unqual_right)) {
9023                         errorf(pos,
9024                                "subtracting pointers to incompatible types '%T' and '%T'",
9025                                orig_type_left, orig_type_right);
9026                 } else if (!is_type_object(unqual_left)) {
9027                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
9028                                 errorf(pos, "subtracting pointers to non-object types '%T'",
9029                                        orig_type_left);
9030                         } else if (warning.other) {
9031                                 warningf(pos, "subtracting pointers to void");
9032                         }
9033                 }
9034                 expression->base.type = type_ptrdiff_t;
9035         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9036                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
9037                        orig_type_left, orig_type_right);
9038         }
9039 }
9040
9041 static void warn_string_literal_address(expression_t const* expr)
9042 {
9043         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
9044                 expr = expr->unary.value;
9045                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
9046                         return;
9047                 expr = expr->unary.value;
9048         }
9049
9050         if (expr->kind == EXPR_STRING_LITERAL ||
9051             expr->kind == EXPR_WIDE_STRING_LITERAL) {
9052                 warningf(&expr->base.source_position,
9053                         "comparison with string literal results in unspecified behaviour");
9054         }
9055 }
9056
9057 static void warn_comparison_in_comparison(const expression_t *const expr)
9058 {
9059         if (expr->base.parenthesized)
9060                 return;
9061         switch (expr->base.kind) {
9062                 case EXPR_BINARY_LESS:
9063                 case EXPR_BINARY_GREATER:
9064                 case EXPR_BINARY_LESSEQUAL:
9065                 case EXPR_BINARY_GREATEREQUAL:
9066                 case EXPR_BINARY_NOTEQUAL:
9067                 case EXPR_BINARY_EQUAL:
9068                         warningf(&expr->base.source_position,
9069                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9070                         break;
9071                 default:
9072                         break;
9073         }
9074 }
9075
9076 static bool maybe_negative(expression_t const *const expr)
9077 {
9078         return
9079                 !is_constant_expression(expr) ||
9080                 fold_constant(expr) < 0;
9081 }
9082
9083 /**
9084  * Check the semantics of comparison expressions.
9085  *
9086  * @param expression   The expression to check.
9087  */
9088 static void semantic_comparison(binary_expression_t *expression)
9089 {
9090         expression_t *left  = expression->left;
9091         expression_t *right = expression->right;
9092
9093         if (warning.address) {
9094                 warn_string_literal_address(left);
9095                 warn_string_literal_address(right);
9096
9097                 expression_t const* const func_left = get_reference_address(left);
9098                 if (func_left != NULL && is_null_pointer_constant(right)) {
9099                         warningf(&expression->base.source_position,
9100                                  "the address of '%Y' will never be NULL",
9101                                  func_left->reference.entity->base.symbol);
9102                 }
9103
9104                 expression_t const* const func_right = get_reference_address(right);
9105                 if (func_right != NULL && is_null_pointer_constant(right)) {
9106                         warningf(&expression->base.source_position,
9107                                  "the address of '%Y' will never be NULL",
9108                                  func_right->reference.entity->base.symbol);
9109                 }
9110         }
9111
9112         if (warning.parentheses) {
9113                 warn_comparison_in_comparison(left);
9114                 warn_comparison_in_comparison(right);
9115         }
9116
9117         type_t *orig_type_left  = left->base.type;
9118         type_t *orig_type_right = right->base.type;
9119         type_t *type_left       = skip_typeref(orig_type_left);
9120         type_t *type_right      = skip_typeref(orig_type_right);
9121
9122         /* TODO non-arithmetic types */
9123         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9124                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9125
9126                 /* test for signed vs unsigned compares */
9127                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9128                         bool const signed_left  = is_type_signed(type_left);
9129                         bool const signed_right = is_type_signed(type_right);
9130                         if (signed_left != signed_right) {
9131                                 /* FIXME long long needs better const folding magic */
9132                                 /* TODO check whether constant value can be represented by other type */
9133                                 if ((signed_left  && maybe_negative(left)) ||
9134                                                 (signed_right && maybe_negative(right))) {
9135                                         warningf(&expression->base.source_position,
9136                                                         "comparison between signed and unsigned");
9137                                 }
9138                         }
9139                 }
9140
9141                 expression->left        = create_implicit_cast(left, arithmetic_type);
9142                 expression->right       = create_implicit_cast(right, arithmetic_type);
9143                 expression->base.type   = arithmetic_type;
9144                 if (warning.float_equal &&
9145                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9146                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9147                     is_type_float(arithmetic_type)) {
9148                         warningf(&expression->base.source_position,
9149                                  "comparing floating point with == or != is unsafe");
9150                 }
9151         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9152                 /* TODO check compatibility */
9153         } else if (is_type_pointer(type_left)) {
9154                 expression->right = create_implicit_cast(right, type_left);
9155         } else if (is_type_pointer(type_right)) {
9156                 expression->left = create_implicit_cast(left, type_right);
9157         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9158                 type_error_incompatible("invalid operands in comparison",
9159                                         &expression->base.source_position,
9160                                         type_left, type_right);
9161         }
9162         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9163 }
9164
9165 /**
9166  * Checks if a compound type has constant fields.
9167  */
9168 static bool has_const_fields(const compound_type_t *type)
9169 {
9170         compound_t *compound = type->compound;
9171         entity_t   *entry    = compound->members.entities;
9172
9173         for (; entry != NULL; entry = entry->base.next) {
9174                 if (!is_declaration(entry))
9175                         continue;
9176
9177                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9178                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9179                         return true;
9180         }
9181
9182         return false;
9183 }
9184
9185 static bool is_valid_assignment_lhs(expression_t const* const left)
9186 {
9187         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9188         type_t *const type_left      = skip_typeref(orig_type_left);
9189
9190         if (!is_lvalue(left)) {
9191                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9192                        left);
9193                 return false;
9194         }
9195
9196         if (left->kind == EXPR_REFERENCE
9197                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9198                 errorf(HERE, "cannot assign to function '%E'", left);
9199                 return false;
9200         }
9201
9202         if (is_type_array(type_left)) {
9203                 errorf(HERE, "cannot assign to array '%E'", left);
9204                 return false;
9205         }
9206         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9207                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9208                        orig_type_left);
9209                 return false;
9210         }
9211         if (is_type_incomplete(type_left)) {
9212                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9213                        left, orig_type_left);
9214                 return false;
9215         }
9216         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9217                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9218                        left, orig_type_left);
9219                 return false;
9220         }
9221
9222         return true;
9223 }
9224
9225 static void semantic_arithmetic_assign(binary_expression_t *expression)
9226 {
9227         expression_t *left            = expression->left;
9228         expression_t *right           = expression->right;
9229         type_t       *orig_type_left  = left->base.type;
9230         type_t       *orig_type_right = right->base.type;
9231
9232         if (!is_valid_assignment_lhs(left))
9233                 return;
9234
9235         type_t *type_left  = skip_typeref(orig_type_left);
9236         type_t *type_right = skip_typeref(orig_type_right);
9237
9238         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9239                 /* TODO: improve error message */
9240                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9241                         errorf(&expression->base.source_position,
9242                                "operation needs arithmetic types");
9243                 }
9244                 return;
9245         }
9246
9247         /* combined instructions are tricky. We can't create an implicit cast on
9248          * the left side, because we need the uncasted form for the store.
9249          * The ast2firm pass has to know that left_type must be right_type
9250          * for the arithmetic operation and create a cast by itself */
9251         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9252         expression->right       = create_implicit_cast(right, arithmetic_type);
9253         expression->base.type   = type_left;
9254 }
9255
9256 static void semantic_divmod_assign(binary_expression_t *expression)
9257 {
9258         semantic_arithmetic_assign(expression);
9259         warn_div_by_zero(expression);
9260 }
9261
9262 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9263 {
9264         expression_t *const left            = expression->left;
9265         expression_t *const right           = expression->right;
9266         type_t       *const orig_type_left  = left->base.type;
9267         type_t       *const orig_type_right = right->base.type;
9268         type_t       *const type_left       = skip_typeref(orig_type_left);
9269         type_t       *const type_right      = skip_typeref(orig_type_right);
9270
9271         if (!is_valid_assignment_lhs(left))
9272                 return;
9273
9274         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9275                 /* combined instructions are tricky. We can't create an implicit cast on
9276                  * the left side, because we need the uncasted form for the store.
9277                  * The ast2firm pass has to know that left_type must be right_type
9278                  * for the arithmetic operation and create a cast by itself */
9279                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9280                 expression->right     = create_implicit_cast(right, arithmetic_type);
9281                 expression->base.type = type_left;
9282         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9283                 check_pointer_arithmetic(&expression->base.source_position,
9284                                          type_left, orig_type_left);
9285                 expression->base.type = type_left;
9286         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9287                 errorf(&expression->base.source_position,
9288                        "incompatible types '%T' and '%T' in assignment",
9289                        orig_type_left, orig_type_right);
9290         }
9291 }
9292
9293 static void warn_logical_and_within_or(const expression_t *const expr)
9294 {
9295         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9296                 return;
9297         if (expr->base.parenthesized)
9298                 return;
9299         warningf(&expr->base.source_position,
9300                         "suggest parentheses around && within ||");
9301 }
9302
9303 /**
9304  * Check the semantic restrictions of a logical expression.
9305  */
9306 static void semantic_logical_op(binary_expression_t *expression)
9307 {
9308         /* §6.5.13:2  Each of the operands shall have scalar type.
9309          * §6.5.14:2  Each of the operands shall have scalar type. */
9310         semantic_condition(expression->left,   "left operand of logical operator");
9311         semantic_condition(expression->right, "right operand of logical operator");
9312         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9313                         warning.parentheses) {
9314                 warn_logical_and_within_or(expression->left);
9315                 warn_logical_and_within_or(expression->right);
9316         }
9317         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9318 }
9319
9320 /**
9321  * Check the semantic restrictions of a binary assign expression.
9322  */
9323 static void semantic_binexpr_assign(binary_expression_t *expression)
9324 {
9325         expression_t *left           = expression->left;
9326         type_t       *orig_type_left = left->base.type;
9327
9328         if (!is_valid_assignment_lhs(left))
9329                 return;
9330
9331         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9332         report_assign_error(error, orig_type_left, expression->right,
9333                         "assignment", &left->base.source_position);
9334         expression->right = create_implicit_cast(expression->right, orig_type_left);
9335         expression->base.type = orig_type_left;
9336 }
9337
9338 /**
9339  * Determine if the outermost operation (or parts thereof) of the given
9340  * expression has no effect in order to generate a warning about this fact.
9341  * Therefore in some cases this only examines some of the operands of the
9342  * expression (see comments in the function and examples below).
9343  * Examples:
9344  *   f() + 23;    // warning, because + has no effect
9345  *   x || f();    // no warning, because x controls execution of f()
9346  *   x ? y : f(); // warning, because y has no effect
9347  *   (void)x;     // no warning to be able to suppress the warning
9348  * This function can NOT be used for an "expression has definitely no effect"-
9349  * analysis. */
9350 static bool expression_has_effect(const expression_t *const expr)
9351 {
9352         switch (expr->kind) {
9353                 case EXPR_UNKNOWN:                    break;
9354                 case EXPR_INVALID:                    return true; /* do NOT warn */
9355                 case EXPR_REFERENCE:                  return false;
9356                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
9357                 /* suppress the warning for microsoft __noop operations */
9358                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
9359                 case EXPR_CHARACTER_CONSTANT:         return false;
9360                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
9361                 case EXPR_STRING_LITERAL:             return false;
9362                 case EXPR_WIDE_STRING_LITERAL:        return false;
9363                 case EXPR_LABEL_ADDRESS:              return false;
9364
9365                 case EXPR_CALL: {
9366                         const call_expression_t *const call = &expr->call;
9367                         if (call->function->kind != EXPR_REFERENCE)
9368                                 return true;
9369
9370                         switch (call->function->reference.entity->function.btk) {
9371                                 /* FIXME: which builtins have no effect? */
9372                                 default:                      return true;
9373                         }
9374                 }
9375
9376                 /* Generate the warning if either the left or right hand side of a
9377                  * conditional expression has no effect */
9378                 case EXPR_CONDITIONAL: {
9379                         conditional_expression_t const *const cond = &expr->conditional;
9380                         expression_t             const *const t    = cond->true_expression;
9381                         return
9382                                 (t == NULL || expression_has_effect(t)) &&
9383                                 expression_has_effect(cond->false_expression);
9384                 }
9385
9386                 case EXPR_SELECT:                     return false;
9387                 case EXPR_ARRAY_ACCESS:               return false;
9388                 case EXPR_SIZEOF:                     return false;
9389                 case EXPR_CLASSIFY_TYPE:              return false;
9390                 case EXPR_ALIGNOF:                    return false;
9391
9392                 case EXPR_FUNCNAME:                   return false;
9393                 case EXPR_BUILTIN_CONSTANT_P:         return false;
9394                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
9395                 case EXPR_OFFSETOF:                   return false;
9396                 case EXPR_VA_START:                   return true;
9397                 case EXPR_VA_ARG:                     return true;
9398                 case EXPR_VA_COPY:                    return true;
9399                 case EXPR_STATEMENT:                  return true; // TODO
9400                 case EXPR_COMPOUND_LITERAL:           return false;
9401
9402                 case EXPR_UNARY_NEGATE:               return false;
9403                 case EXPR_UNARY_PLUS:                 return false;
9404                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
9405                 case EXPR_UNARY_NOT:                  return false;
9406                 case EXPR_UNARY_DEREFERENCE:          return false;
9407                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
9408                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
9409                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
9410                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
9411                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
9412
9413                 /* Treat void casts as if they have an effect in order to being able to
9414                  * suppress the warning */
9415                 case EXPR_UNARY_CAST: {
9416                         type_t *const type = skip_typeref(expr->base.type);
9417                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9418                 }
9419
9420                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
9421                 case EXPR_UNARY_ASSUME:               return true;
9422                 case EXPR_UNARY_DELETE:               return true;
9423                 case EXPR_UNARY_DELETE_ARRAY:         return true;
9424                 case EXPR_UNARY_THROW:                return true;
9425
9426                 case EXPR_BINARY_ADD:                 return false;
9427                 case EXPR_BINARY_SUB:                 return false;
9428                 case EXPR_BINARY_MUL:                 return false;
9429                 case EXPR_BINARY_DIV:                 return false;
9430                 case EXPR_BINARY_MOD:                 return false;
9431                 case EXPR_BINARY_EQUAL:               return false;
9432                 case EXPR_BINARY_NOTEQUAL:            return false;
9433                 case EXPR_BINARY_LESS:                return false;
9434                 case EXPR_BINARY_LESSEQUAL:           return false;
9435                 case EXPR_BINARY_GREATER:             return false;
9436                 case EXPR_BINARY_GREATEREQUAL:        return false;
9437                 case EXPR_BINARY_BITWISE_AND:         return false;
9438                 case EXPR_BINARY_BITWISE_OR:          return false;
9439                 case EXPR_BINARY_BITWISE_XOR:         return false;
9440                 case EXPR_BINARY_SHIFTLEFT:           return false;
9441                 case EXPR_BINARY_SHIFTRIGHT:          return false;
9442                 case EXPR_BINARY_ASSIGN:              return true;
9443                 case EXPR_BINARY_MUL_ASSIGN:          return true;
9444                 case EXPR_BINARY_DIV_ASSIGN:          return true;
9445                 case EXPR_BINARY_MOD_ASSIGN:          return true;
9446                 case EXPR_BINARY_ADD_ASSIGN:          return true;
9447                 case EXPR_BINARY_SUB_ASSIGN:          return true;
9448                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
9449                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
9450                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
9451                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
9452                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
9453
9454                 /* Only examine the right hand side of && and ||, because the left hand
9455                  * side already has the effect of controlling the execution of the right
9456                  * hand side */
9457                 case EXPR_BINARY_LOGICAL_AND:
9458                 case EXPR_BINARY_LOGICAL_OR:
9459                 /* Only examine the right hand side of a comma expression, because the left
9460                  * hand side has a separate warning */
9461                 case EXPR_BINARY_COMMA:
9462                         return expression_has_effect(expr->binary.right);
9463
9464                 case EXPR_BINARY_ISGREATER:           return false;
9465                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
9466                 case EXPR_BINARY_ISLESS:              return false;
9467                 case EXPR_BINARY_ISLESSEQUAL:         return false;
9468                 case EXPR_BINARY_ISLESSGREATER:       return false;
9469                 case EXPR_BINARY_ISUNORDERED:         return false;
9470         }
9471
9472         internal_errorf(HERE, "unexpected expression");
9473 }
9474
9475 static void semantic_comma(binary_expression_t *expression)
9476 {
9477         if (warning.unused_value) {
9478                 const expression_t *const left = expression->left;
9479                 if (!expression_has_effect(left)) {
9480                         warningf(&left->base.source_position,
9481                                  "left-hand operand of comma expression has no effect");
9482                 }
9483         }
9484         expression->base.type = expression->right->base.type;
9485 }
9486
9487 /**
9488  * @param prec_r precedence of the right operand
9489  */
9490 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9491 static expression_t *parse_##binexpression_type(expression_t *left)          \
9492 {                                                                            \
9493         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9494         binexpr->binary.left  = left;                                            \
9495         eat(token_type);                                                         \
9496                                                                              \
9497         expression_t *right = parse_sub_expression(prec_r);                      \
9498                                                                              \
9499         binexpr->binary.right = right;                                           \
9500         sfunc(&binexpr->binary);                                                 \
9501                                                                              \
9502         return binexpr;                                                          \
9503 }
9504
9505 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9506 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9507 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9508 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9509 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9510 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9511 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9512 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9513 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9514 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9515 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9516 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9517 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9518 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9519 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9520 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9521 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9522 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9523 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9524 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9525 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9526 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9527 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9528 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9529 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9530 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9531 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9532 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9533 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9534 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9535
9536
9537 static expression_t *parse_sub_expression(precedence_t precedence)
9538 {
9539         if (token.type < 0) {
9540                 return expected_expression_error();
9541         }
9542
9543         expression_parser_function_t *parser
9544                 = &expression_parsers[token.type];
9545         source_position_t             source_position = token.source_position;
9546         expression_t                 *left;
9547
9548         if (parser->parser != NULL) {
9549                 left = parser->parser();
9550         } else {
9551                 left = parse_primary_expression();
9552         }
9553         assert(left != NULL);
9554         left->base.source_position = source_position;
9555
9556         while (true) {
9557                 if (token.type < 0) {
9558                         return expected_expression_error();
9559                 }
9560
9561                 parser = &expression_parsers[token.type];
9562                 if (parser->infix_parser == NULL)
9563                         break;
9564                 if (parser->infix_precedence < precedence)
9565                         break;
9566
9567                 left = parser->infix_parser(left);
9568
9569                 assert(left != NULL);
9570                 assert(left->kind != EXPR_UNKNOWN);
9571                 left->base.source_position = source_position;
9572         }
9573
9574         return left;
9575 }
9576
9577 /**
9578  * Parse an expression.
9579  */
9580 static expression_t *parse_expression(void)
9581 {
9582         return parse_sub_expression(PREC_EXPRESSION);
9583 }
9584
9585 /**
9586  * Register a parser for a prefix-like operator.
9587  *
9588  * @param parser      the parser function
9589  * @param token_type  the token type of the prefix token
9590  */
9591 static void register_expression_parser(parse_expression_function parser,
9592                                        int token_type)
9593 {
9594         expression_parser_function_t *entry = &expression_parsers[token_type];
9595
9596         if (entry->parser != NULL) {
9597                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9598                 panic("trying to register multiple expression parsers for a token");
9599         }
9600         entry->parser = parser;
9601 }
9602
9603 /**
9604  * Register a parser for an infix operator with given precedence.
9605  *
9606  * @param parser      the parser function
9607  * @param token_type  the token type of the infix operator
9608  * @param precedence  the precedence of the operator
9609  */
9610 static void register_infix_parser(parse_expression_infix_function parser,
9611                 int token_type, precedence_t precedence)
9612 {
9613         expression_parser_function_t *entry = &expression_parsers[token_type];
9614
9615         if (entry->infix_parser != NULL) {
9616                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9617                 panic("trying to register multiple infix expression parsers for a "
9618                       "token");
9619         }
9620         entry->infix_parser     = parser;
9621         entry->infix_precedence = precedence;
9622 }
9623
9624 /**
9625  * Initialize the expression parsers.
9626  */
9627 static void init_expression_parsers(void)
9628 {
9629         memset(&expression_parsers, 0, sizeof(expression_parsers));
9630
9631         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9632         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9633         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9634         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9635         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9636         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9637         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9638         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9639         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9640         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9641         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9642         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9643         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9644         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9645         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9646         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9647         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9648         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9649         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9650         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9651         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9652         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9653         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9654         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9655         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9656         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9657         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9658         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9659         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9660         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9661         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9662         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9663         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9664         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9665         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9666         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9667         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9668
9669         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9670         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9671         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9672         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9673         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9674         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9675         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9676         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9677         register_expression_parser(parse_sizeof,                      T_sizeof);
9678         register_expression_parser(parse_alignof,                     T___alignof__);
9679         register_expression_parser(parse_extension,                   T___extension__);
9680         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9681         register_expression_parser(parse_delete,                      T_delete);
9682         register_expression_parser(parse_throw,                       T_throw);
9683 }
9684
9685 /**
9686  * Parse a asm statement arguments specification.
9687  */
9688 static asm_argument_t *parse_asm_arguments(bool is_out)
9689 {
9690         asm_argument_t  *result = NULL;
9691         asm_argument_t **anchor = &result;
9692
9693         while (token.type == T_STRING_LITERAL || token.type == '[') {
9694                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9695                 memset(argument, 0, sizeof(argument[0]));
9696
9697                 if (token.type == '[') {
9698                         eat('[');
9699                         if (token.type != T_IDENTIFIER) {
9700                                 parse_error_expected("while parsing asm argument",
9701                                                      T_IDENTIFIER, NULL);
9702                                 return NULL;
9703                         }
9704                         argument->symbol = token.v.symbol;
9705
9706                         expect(']', end_error);
9707                 }
9708
9709                 argument->constraints = parse_string_literals();
9710                 expect('(', end_error);
9711                 add_anchor_token(')');
9712                 expression_t *expression = parse_expression();
9713                 rem_anchor_token(')');
9714                 if (is_out) {
9715                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9716                          * change size or type representation (e.g. int -> long is ok, but
9717                          * int -> float is not) */
9718                         if (expression->kind == EXPR_UNARY_CAST) {
9719                                 type_t      *const type = expression->base.type;
9720                                 type_kind_t  const kind = type->kind;
9721                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9722                                         unsigned flags;
9723                                         unsigned size;
9724                                         if (kind == TYPE_ATOMIC) {
9725                                                 atomic_type_kind_t const akind = type->atomic.akind;
9726                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9727                                                 size  = get_atomic_type_size(akind);
9728                                         } else {
9729                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9730                                                 size  = get_atomic_type_size(get_intptr_kind());
9731                                         }
9732
9733                                         do {
9734                                                 expression_t *const value      = expression->unary.value;
9735                                                 type_t       *const value_type = value->base.type;
9736                                                 type_kind_t   const value_kind = value_type->kind;
9737
9738                                                 unsigned value_flags;
9739                                                 unsigned value_size;
9740                                                 if (value_kind == TYPE_ATOMIC) {
9741                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9742                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9743                                                         value_size  = get_atomic_type_size(value_akind);
9744                                                 } else if (value_kind == TYPE_POINTER) {
9745                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9746                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9747                                                 } else {
9748                                                         break;
9749                                                 }
9750
9751                                                 if (value_flags != flags || value_size != size)
9752                                                         break;
9753
9754                                                 expression = value;
9755                                         } while (expression->kind == EXPR_UNARY_CAST);
9756                                 }
9757                         }
9758
9759                         if (!is_lvalue(expression)) {
9760                                 errorf(&expression->base.source_position,
9761                                        "asm output argument is not an lvalue");
9762                         }
9763
9764                         if (argument->constraints.begin[0] == '+')
9765                                 mark_vars_read(expression, NULL);
9766                 } else {
9767                         mark_vars_read(expression, NULL);
9768                 }
9769                 argument->expression = expression;
9770                 expect(')', end_error);
9771
9772                 set_address_taken(expression, true);
9773
9774                 *anchor = argument;
9775                 anchor  = &argument->next;
9776
9777                 if (token.type != ',')
9778                         break;
9779                 eat(',');
9780         }
9781
9782         return result;
9783 end_error:
9784         return NULL;
9785 }
9786
9787 /**
9788  * Parse a asm statement clobber specification.
9789  */
9790 static asm_clobber_t *parse_asm_clobbers(void)
9791 {
9792         asm_clobber_t *result = NULL;
9793         asm_clobber_t *last   = NULL;
9794
9795         while (token.type == T_STRING_LITERAL) {
9796                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9797                 clobber->clobber       = parse_string_literals();
9798
9799                 if (last != NULL) {
9800                         last->next = clobber;
9801                 } else {
9802                         result = clobber;
9803                 }
9804                 last = clobber;
9805
9806                 if (token.type != ',')
9807                         break;
9808                 eat(',');
9809         }
9810
9811         return result;
9812 }
9813
9814 /**
9815  * Parse an asm statement.
9816  */
9817 static statement_t *parse_asm_statement(void)
9818 {
9819         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9820         asm_statement_t *asm_statement = &statement->asms;
9821
9822         eat(T_asm);
9823
9824         if (token.type == T_volatile) {
9825                 next_token();
9826                 asm_statement->is_volatile = true;
9827         }
9828
9829         expect('(', end_error);
9830         add_anchor_token(')');
9831         add_anchor_token(':');
9832         asm_statement->asm_text = parse_string_literals();
9833
9834         if (token.type != ':') {
9835                 rem_anchor_token(':');
9836                 goto end_of_asm;
9837         }
9838         eat(':');
9839
9840         asm_statement->outputs = parse_asm_arguments(true);
9841         if (token.type != ':') {
9842                 rem_anchor_token(':');
9843                 goto end_of_asm;
9844         }
9845         eat(':');
9846
9847         asm_statement->inputs = parse_asm_arguments(false);
9848         if (token.type != ':') {
9849                 rem_anchor_token(':');
9850                 goto end_of_asm;
9851         }
9852         rem_anchor_token(':');
9853         eat(':');
9854
9855         asm_statement->clobbers = parse_asm_clobbers();
9856
9857 end_of_asm:
9858         rem_anchor_token(')');
9859         expect(')', end_error);
9860         expect(';', end_error);
9861
9862         if (asm_statement->outputs == NULL) {
9863                 /* GCC: An 'asm' instruction without any output operands will be treated
9864                  * identically to a volatile 'asm' instruction. */
9865                 asm_statement->is_volatile = true;
9866         }
9867
9868         return statement;
9869 end_error:
9870         return create_invalid_statement();
9871 }
9872
9873 /**
9874  * Parse a case statement.
9875  */
9876 static statement_t *parse_case_statement(void)
9877 {
9878         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9879         source_position_t *const pos       = &statement->base.source_position;
9880
9881         eat(T_case);
9882
9883         expression_t *const expression   = parse_expression();
9884         statement->case_label.expression = expression;
9885         if (!is_constant_expression(expression)) {
9886                 /* This check does not prevent the error message in all cases of an
9887                  * prior error while parsing the expression.  At least it catches the
9888                  * common case of a mistyped enum entry. */
9889                 if (is_type_valid(skip_typeref(expression->base.type))) {
9890                         errorf(pos, "case label does not reduce to an integer constant");
9891                 }
9892                 statement->case_label.is_bad = true;
9893         } else {
9894                 long const val = fold_constant(expression);
9895                 statement->case_label.first_case = val;
9896                 statement->case_label.last_case  = val;
9897         }
9898
9899         if (GNU_MODE) {
9900                 if (token.type == T_DOTDOTDOT) {
9901                         next_token();
9902                         expression_t *const end_range   = parse_expression();
9903                         statement->case_label.end_range = end_range;
9904                         if (!is_constant_expression(end_range)) {
9905                                 /* This check does not prevent the error message in all cases of an
9906                                  * prior error while parsing the expression.  At least it catches the
9907                                  * common case of a mistyped enum entry. */
9908                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9909                                         errorf(pos, "case range does not reduce to an integer constant");
9910                                 }
9911                                 statement->case_label.is_bad = true;
9912                         } else {
9913                                 long const val = fold_constant(end_range);
9914                                 statement->case_label.last_case = val;
9915
9916                                 if (warning.other && val < statement->case_label.first_case) {
9917                                         statement->case_label.is_empty_range = true;
9918                                         warningf(pos, "empty range specified");
9919                                 }
9920                         }
9921                 }
9922         }
9923
9924         PUSH_PARENT(statement);
9925
9926         expect(':', end_error);
9927 end_error:
9928
9929         if (current_switch != NULL) {
9930                 if (! statement->case_label.is_bad) {
9931                         /* Check for duplicate case values */
9932                         case_label_statement_t *c = &statement->case_label;
9933                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9934                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9935                                         continue;
9936
9937                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9938                                         continue;
9939
9940                                 errorf(pos, "duplicate case value (previously used %P)",
9941                                        &l->base.source_position);
9942                                 break;
9943                         }
9944                 }
9945                 /* link all cases into the switch statement */
9946                 if (current_switch->last_case == NULL) {
9947                         current_switch->first_case      = &statement->case_label;
9948                 } else {
9949                         current_switch->last_case->next = &statement->case_label;
9950                 }
9951                 current_switch->last_case = &statement->case_label;
9952         } else {
9953                 errorf(pos, "case label not within a switch statement");
9954         }
9955
9956         statement_t *const inner_stmt = parse_statement();
9957         statement->case_label.statement = inner_stmt;
9958         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9959                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9960         }
9961
9962         POP_PARENT;
9963         return statement;
9964 }
9965
9966 /**
9967  * Parse a default statement.
9968  */
9969 static statement_t *parse_default_statement(void)
9970 {
9971         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9972
9973         eat(T_default);
9974
9975         PUSH_PARENT(statement);
9976
9977         expect(':', end_error);
9978         if (current_switch != NULL) {
9979                 const case_label_statement_t *def_label = current_switch->default_label;
9980                 if (def_label != NULL) {
9981                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9982                                &def_label->base.source_position);
9983                 } else {
9984                         current_switch->default_label = &statement->case_label;
9985
9986                         /* link all cases into the switch statement */
9987                         if (current_switch->last_case == NULL) {
9988                                 current_switch->first_case      = &statement->case_label;
9989                         } else {
9990                                 current_switch->last_case->next = &statement->case_label;
9991                         }
9992                         current_switch->last_case = &statement->case_label;
9993                 }
9994         } else {
9995                 errorf(&statement->base.source_position,
9996                         "'default' label not within a switch statement");
9997         }
9998
9999         statement_t *const inner_stmt = parse_statement();
10000         statement->case_label.statement = inner_stmt;
10001         if (inner_stmt->kind == STATEMENT_DECLARATION) {
10002                 errorf(&inner_stmt->base.source_position, "declaration after default label");
10003         }
10004
10005         POP_PARENT;
10006         return statement;
10007 end_error:
10008         POP_PARENT;
10009         return create_invalid_statement();
10010 }
10011
10012 /**
10013  * Parse a label statement.
10014  */
10015 static statement_t *parse_label_statement(void)
10016 {
10017         assert(token.type == T_IDENTIFIER);
10018         symbol_t *symbol = token.v.symbol;
10019         label_t  *label  = get_label(symbol);
10020
10021         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
10022         statement->label.label       = label;
10023
10024         next_token();
10025
10026         PUSH_PARENT(statement);
10027
10028         /* if statement is already set then the label is defined twice,
10029          * otherwise it was just mentioned in a goto/local label declaration so far
10030          */
10031         if (label->statement != NULL) {
10032                 errorf(HERE, "duplicate label '%Y' (declared %P)",
10033                        symbol, &label->base.source_position);
10034         } else {
10035                 label->base.source_position = token.source_position;
10036                 label->statement            = statement;
10037         }
10038
10039         eat(':');
10040
10041         if (token.type == '}') {
10042                 /* TODO only warn? */
10043                 if (warning.other && false) {
10044                         warningf(HERE, "label at end of compound statement");
10045                         statement->label.statement = create_empty_statement();
10046                 } else {
10047                         errorf(HERE, "label at end of compound statement");
10048                         statement->label.statement = create_invalid_statement();
10049                 }
10050         } else if (token.type == ';') {
10051                 /* Eat an empty statement here, to avoid the warning about an empty
10052                  * statement after a label.  label:; is commonly used to have a label
10053                  * before a closing brace. */
10054                 statement->label.statement = create_empty_statement();
10055                 next_token();
10056         } else {
10057                 statement_t *const inner_stmt = parse_statement();
10058                 statement->label.statement = inner_stmt;
10059                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
10060                         errorf(&inner_stmt->base.source_position, "declaration after label");
10061                 }
10062         }
10063
10064         /* remember the labels in a list for later checking */
10065         *label_anchor = &statement->label;
10066         label_anchor  = &statement->label.next;
10067
10068         POP_PARENT;
10069         return statement;
10070 }
10071
10072 /**
10073  * Parse an if statement.
10074  */
10075 static statement_t *parse_if(void)
10076 {
10077         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10078
10079         eat(T_if);
10080
10081         PUSH_PARENT(statement);
10082
10083         add_anchor_token('{');
10084
10085         expect('(', end_error);
10086         add_anchor_token(')');
10087         expression_t *const expr = parse_expression();
10088         statement->ifs.condition = expr;
10089         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10090          *             scalar type. */
10091         semantic_condition(expr, "condition of 'if'-statment");
10092         mark_vars_read(expr, NULL);
10093         rem_anchor_token(')');
10094         expect(')', end_error);
10095
10096 end_error:
10097         rem_anchor_token('{');
10098
10099         add_anchor_token(T_else);
10100         statement_t *const true_stmt = parse_statement();
10101         statement->ifs.true_statement = true_stmt;
10102         rem_anchor_token(T_else);
10103
10104         if (token.type == T_else) {
10105                 next_token();
10106                 statement->ifs.false_statement = parse_statement();
10107         } else if (warning.parentheses &&
10108                         true_stmt->kind == STATEMENT_IF &&
10109                         true_stmt->ifs.false_statement != NULL) {
10110                 warningf(&true_stmt->base.source_position,
10111                                 "suggest explicit braces to avoid ambiguous 'else'");
10112         }
10113
10114         POP_PARENT;
10115         return statement;
10116 }
10117
10118 /**
10119  * Check that all enums are handled in a switch.
10120  *
10121  * @param statement  the switch statement to check
10122  */
10123 static void check_enum_cases(const switch_statement_t *statement)
10124 {
10125         const type_t *type = skip_typeref(statement->expression->base.type);
10126         if (! is_type_enum(type))
10127                 return;
10128         const enum_type_t *enumt = &type->enumt;
10129
10130         /* if we have a default, no warnings */
10131         if (statement->default_label != NULL)
10132                 return;
10133
10134         /* FIXME: calculation of value should be done while parsing */
10135         /* TODO: quadratic algorithm here. Change to an n log n one */
10136         long            last_value = -1;
10137         const entity_t *entry      = enumt->enume->base.next;
10138         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10139              entry = entry->base.next) {
10140                 const expression_t *expression = entry->enum_value.value;
10141                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10142                 bool                found      = false;
10143                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10144                         if (l->expression == NULL)
10145                                 continue;
10146                         if (l->first_case <= value && value <= l->last_case) {
10147                                 found = true;
10148                                 break;
10149                         }
10150                 }
10151                 if (! found) {
10152                         warningf(&statement->base.source_position,
10153                                  "enumeration value '%Y' not handled in switch",
10154                                  entry->base.symbol);
10155                 }
10156                 last_value = value;
10157         }
10158 }
10159
10160 /**
10161  * Parse a switch statement.
10162  */
10163 static statement_t *parse_switch(void)
10164 {
10165         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10166
10167         eat(T_switch);
10168
10169         PUSH_PARENT(statement);
10170
10171         expect('(', end_error);
10172         add_anchor_token(')');
10173         expression_t *const expr = parse_expression();
10174         mark_vars_read(expr, NULL);
10175         type_t       *      type = skip_typeref(expr->base.type);
10176         if (is_type_integer(type)) {
10177                 type = promote_integer(type);
10178                 if (warning.traditional) {
10179                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10180                                 warningf(&expr->base.source_position,
10181                                         "'%T' switch expression not converted to '%T' in ISO C",
10182                                         type, type_int);
10183                         }
10184                 }
10185         } else if (is_type_valid(type)) {
10186                 errorf(&expr->base.source_position,
10187                        "switch quantity is not an integer, but '%T'", type);
10188                 type = type_error_type;
10189         }
10190         statement->switchs.expression = create_implicit_cast(expr, type);
10191         expect(')', end_error);
10192         rem_anchor_token(')');
10193
10194         switch_statement_t *rem = current_switch;
10195         current_switch          = &statement->switchs;
10196         statement->switchs.body = parse_statement();
10197         current_switch          = rem;
10198
10199         if (warning.switch_default &&
10200             statement->switchs.default_label == NULL) {
10201                 warningf(&statement->base.source_position, "switch has no default case");
10202         }
10203         if (warning.switch_enum)
10204                 check_enum_cases(&statement->switchs);
10205
10206         POP_PARENT;
10207         return statement;
10208 end_error:
10209         POP_PARENT;
10210         return create_invalid_statement();
10211 }
10212
10213 static statement_t *parse_loop_body(statement_t *const loop)
10214 {
10215         statement_t *const rem = current_loop;
10216         current_loop = loop;
10217
10218         statement_t *const body = parse_statement();
10219
10220         current_loop = rem;
10221         return body;
10222 }
10223
10224 /**
10225  * Parse a while statement.
10226  */
10227 static statement_t *parse_while(void)
10228 {
10229         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10230
10231         eat(T_while);
10232
10233         PUSH_PARENT(statement);
10234
10235         expect('(', end_error);
10236         add_anchor_token(')');
10237         expression_t *const cond = parse_expression();
10238         statement->whiles.condition = cond;
10239         /* §6.8.5:2    The controlling expression of an iteration statement shall
10240          *             have scalar type. */
10241         semantic_condition(cond, "condition of 'while'-statement");
10242         mark_vars_read(cond, NULL);
10243         rem_anchor_token(')');
10244         expect(')', end_error);
10245
10246         statement->whiles.body = parse_loop_body(statement);
10247
10248         POP_PARENT;
10249         return statement;
10250 end_error:
10251         POP_PARENT;
10252         return create_invalid_statement();
10253 }
10254
10255 /**
10256  * Parse a do statement.
10257  */
10258 static statement_t *parse_do(void)
10259 {
10260         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10261
10262         eat(T_do);
10263
10264         PUSH_PARENT(statement);
10265
10266         add_anchor_token(T_while);
10267         statement->do_while.body = parse_loop_body(statement);
10268         rem_anchor_token(T_while);
10269
10270         expect(T_while, end_error);
10271         expect('(', end_error);
10272         add_anchor_token(')');
10273         expression_t *const cond = parse_expression();
10274         statement->do_while.condition = cond;
10275         /* §6.8.5:2    The controlling expression of an iteration statement shall
10276          *             have scalar type. */
10277         semantic_condition(cond, "condition of 'do-while'-statement");
10278         mark_vars_read(cond, NULL);
10279         rem_anchor_token(')');
10280         expect(')', end_error);
10281         expect(';', end_error);
10282
10283         POP_PARENT;
10284         return statement;
10285 end_error:
10286         POP_PARENT;
10287         return create_invalid_statement();
10288 }
10289
10290 /**
10291  * Parse a for statement.
10292  */
10293 static statement_t *parse_for(void)
10294 {
10295         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10296
10297         eat(T_for);
10298
10299         expect('(', end_error1);
10300         add_anchor_token(')');
10301
10302         PUSH_PARENT(statement);
10303
10304         size_t const  top       = environment_top();
10305         scope_t      *old_scope = scope_push(&statement->fors.scope);
10306
10307         if (token.type == ';') {
10308                 next_token();
10309         } else if (is_declaration_specifier(&token, false)) {
10310                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10311         } else {
10312                 add_anchor_token(';');
10313                 expression_t *const init = parse_expression();
10314                 statement->fors.initialisation = init;
10315                 mark_vars_read(init, ENT_ANY);
10316                 if (warning.unused_value && !expression_has_effect(init)) {
10317                         warningf(&init->base.source_position,
10318                                         "initialisation of 'for'-statement has no effect");
10319                 }
10320                 rem_anchor_token(';');
10321                 expect(';', end_error2);
10322         }
10323
10324         if (token.type != ';') {
10325                 add_anchor_token(';');
10326                 expression_t *const cond = parse_expression();
10327                 statement->fors.condition = cond;
10328                 /* §6.8.5:2    The controlling expression of an iteration statement
10329                  *             shall have scalar type. */
10330                 semantic_condition(cond, "condition of 'for'-statement");
10331                 mark_vars_read(cond, NULL);
10332                 rem_anchor_token(';');
10333         }
10334         expect(';', end_error2);
10335         if (token.type != ')') {
10336                 expression_t *const step = parse_expression();
10337                 statement->fors.step = step;
10338                 mark_vars_read(step, ENT_ANY);
10339                 if (warning.unused_value && !expression_has_effect(step)) {
10340                         warningf(&step->base.source_position,
10341                                  "step of 'for'-statement has no effect");
10342                 }
10343         }
10344         expect(')', end_error2);
10345         rem_anchor_token(')');
10346         statement->fors.body = parse_loop_body(statement);
10347
10348         assert(current_scope == &statement->fors.scope);
10349         scope_pop(old_scope);
10350         environment_pop_to(top);
10351
10352         POP_PARENT;
10353         return statement;
10354
10355 end_error2:
10356         POP_PARENT;
10357         rem_anchor_token(')');
10358         assert(current_scope == &statement->fors.scope);
10359         scope_pop(old_scope);
10360         environment_pop_to(top);
10361         /* fallthrough */
10362
10363 end_error1:
10364         return create_invalid_statement();
10365 }
10366
10367 /**
10368  * Parse a goto statement.
10369  */
10370 static statement_t *parse_goto(void)
10371 {
10372         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10373         eat(T_goto);
10374
10375         if (GNU_MODE && token.type == '*') {
10376                 next_token();
10377                 expression_t *expression = parse_expression();
10378                 mark_vars_read(expression, NULL);
10379
10380                 /* Argh: although documentation says the expression must be of type void*,
10381                  * gcc accepts anything that can be casted into void* without error */
10382                 type_t *type = expression->base.type;
10383
10384                 if (type != type_error_type) {
10385                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10386                                 errorf(&expression->base.source_position,
10387                                         "cannot convert to a pointer type");
10388                         } else if (warning.other && type != type_void_ptr) {
10389                                 warningf(&expression->base.source_position,
10390                                         "type of computed goto expression should be 'void*' not '%T'", type);
10391                         }
10392                         expression = create_implicit_cast(expression, type_void_ptr);
10393                 }
10394
10395                 statement->gotos.expression = expression;
10396         } else {
10397                 if (token.type != T_IDENTIFIER) {
10398                         if (GNU_MODE)
10399                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10400                         else
10401                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10402                         eat_until_anchor();
10403                         goto end_error;
10404                 }
10405                 symbol_t *symbol = token.v.symbol;
10406                 next_token();
10407
10408                 statement->gotos.label = get_label(symbol);
10409         }
10410
10411         /* remember the goto's in a list for later checking */
10412         *goto_anchor = &statement->gotos;
10413         goto_anchor  = &statement->gotos.next;
10414
10415         expect(';', end_error);
10416
10417         return statement;
10418 end_error:
10419         return create_invalid_statement();
10420 }
10421
10422 /**
10423  * Parse a continue statement.
10424  */
10425 static statement_t *parse_continue(void)
10426 {
10427         if (current_loop == NULL) {
10428                 errorf(HERE, "continue statement not within loop");
10429         }
10430
10431         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10432
10433         eat(T_continue);
10434         expect(';', end_error);
10435
10436 end_error:
10437         return statement;
10438 }
10439
10440 /**
10441  * Parse a break statement.
10442  */
10443 static statement_t *parse_break(void)
10444 {
10445         if (current_switch == NULL && current_loop == NULL) {
10446                 errorf(HERE, "break statement not within loop or switch");
10447         }
10448
10449         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10450
10451         eat(T_break);
10452         expect(';', end_error);
10453
10454 end_error:
10455         return statement;
10456 }
10457
10458 /**
10459  * Parse a __leave statement.
10460  */
10461 static statement_t *parse_leave_statement(void)
10462 {
10463         if (current_try == NULL) {
10464                 errorf(HERE, "__leave statement not within __try");
10465         }
10466
10467         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10468
10469         eat(T___leave);
10470         expect(';', end_error);
10471
10472 end_error:
10473         return statement;
10474 }
10475
10476 /**
10477  * Check if a given entity represents a local variable.
10478  */
10479 static bool is_local_variable(const entity_t *entity)
10480 {
10481         if (entity->kind != ENTITY_VARIABLE)
10482                 return false;
10483
10484         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10485         case STORAGE_CLASS_AUTO:
10486         case STORAGE_CLASS_REGISTER: {
10487                 const type_t *type = skip_typeref(entity->declaration.type);
10488                 if (is_type_function(type)) {
10489                         return false;
10490                 } else {
10491                         return true;
10492                 }
10493         }
10494         default:
10495                 return false;
10496         }
10497 }
10498
10499 /**
10500  * Check if a given expression represents a local variable.
10501  */
10502 static bool expression_is_local_variable(const expression_t *expression)
10503 {
10504         if (expression->base.kind != EXPR_REFERENCE) {
10505                 return false;
10506         }
10507         const entity_t *entity = expression->reference.entity;
10508         return is_local_variable(entity);
10509 }
10510
10511 /**
10512  * Check if a given expression represents a local variable and
10513  * return its declaration then, else return NULL.
10514  */
10515 entity_t *expression_is_variable(const expression_t *expression)
10516 {
10517         if (expression->base.kind != EXPR_REFERENCE) {
10518                 return NULL;
10519         }
10520         entity_t *entity = expression->reference.entity;
10521         if (entity->kind != ENTITY_VARIABLE)
10522                 return NULL;
10523
10524         return entity;
10525 }
10526
10527 /**
10528  * Parse a return statement.
10529  */
10530 static statement_t *parse_return(void)
10531 {
10532         eat(T_return);
10533
10534         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10535
10536         expression_t *return_value = NULL;
10537         if (token.type != ';') {
10538                 return_value = parse_expression();
10539                 mark_vars_read(return_value, NULL);
10540         }
10541
10542         const type_t *const func_type = skip_typeref(current_function->base.type);
10543         assert(is_type_function(func_type));
10544         type_t *const return_type = skip_typeref(func_type->function.return_type);
10545
10546         source_position_t const *const pos = &statement->base.source_position;
10547         if (return_value != NULL) {
10548                 type_t *return_value_type = skip_typeref(return_value->base.type);
10549
10550                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10551                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10552                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10553                                 /* Only warn in C mode, because GCC does the same */
10554                                 if (c_mode & _CXX || strict_mode) {
10555                                         errorf(pos,
10556                                                         "'return' with a value, in function returning 'void'");
10557                                 } else if (warning.other) {
10558                                         warningf(pos,
10559                                                         "'return' with a value, in function returning 'void'");
10560                                 }
10561                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10562                                 /* Only warn in C mode, because GCC does the same */
10563                                 if (strict_mode) {
10564                                         errorf(pos,
10565                                                         "'return' with expression in function return 'void'");
10566                                 } else if (warning.other) {
10567                                         warningf(pos,
10568                                                         "'return' with expression in function return 'void'");
10569                                 }
10570                         }
10571                 } else {
10572                         assign_error_t error = semantic_assign(return_type, return_value);
10573                         report_assign_error(error, return_type, return_value, "'return'",
10574                                         pos);
10575                 }
10576                 return_value = create_implicit_cast(return_value, return_type);
10577                 /* check for returning address of a local var */
10578                 if (warning.other && return_value != NULL
10579                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10580                         const expression_t *expression = return_value->unary.value;
10581                         if (expression_is_local_variable(expression)) {
10582                                 warningf(pos, "function returns address of local variable");
10583                         }
10584                 }
10585         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10586                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10587                 if (c_mode & _CXX || strict_mode) {
10588                         errorf(pos,
10589                                         "'return' without value, in function returning non-void");
10590                 } else {
10591                         warningf(pos,
10592                                         "'return' without value, in function returning non-void");
10593                 }
10594         }
10595         statement->returns.value = return_value;
10596
10597         expect(';', end_error);
10598
10599 end_error:
10600         return statement;
10601 }
10602
10603 /**
10604  * Parse a declaration statement.
10605  */
10606 static statement_t *parse_declaration_statement(void)
10607 {
10608         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10609
10610         entity_t *before = current_scope->last_entity;
10611         if (GNU_MODE) {
10612                 parse_external_declaration();
10613         } else {
10614                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10615         }
10616
10617         declaration_statement_t *const decl  = &statement->declaration;
10618         entity_t                *const begin =
10619                 before != NULL ? before->base.next : current_scope->entities;
10620         decl->declarations_begin = begin;
10621         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10622
10623         return statement;
10624 }
10625
10626 /**
10627  * Parse an expression statement, ie. expr ';'.
10628  */
10629 static statement_t *parse_expression_statement(void)
10630 {
10631         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10632
10633         expression_t *const expr         = parse_expression();
10634         statement->expression.expression = expr;
10635         mark_vars_read(expr, ENT_ANY);
10636
10637         expect(';', end_error);
10638
10639 end_error:
10640         return statement;
10641 }
10642
10643 /**
10644  * Parse a microsoft __try { } __finally { } or
10645  * __try{ } __except() { }
10646  */
10647 static statement_t *parse_ms_try_statment(void)
10648 {
10649         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10650         eat(T___try);
10651
10652         PUSH_PARENT(statement);
10653
10654         ms_try_statement_t *rem = current_try;
10655         current_try = &statement->ms_try;
10656         statement->ms_try.try_statement = parse_compound_statement(false);
10657         current_try = rem;
10658
10659         POP_PARENT;
10660
10661         if (token.type == T___except) {
10662                 eat(T___except);
10663                 expect('(', end_error);
10664                 add_anchor_token(')');
10665                 expression_t *const expr = parse_expression();
10666                 mark_vars_read(expr, NULL);
10667                 type_t       *      type = skip_typeref(expr->base.type);
10668                 if (is_type_integer(type)) {
10669                         type = promote_integer(type);
10670                 } else if (is_type_valid(type)) {
10671                         errorf(&expr->base.source_position,
10672                                "__expect expression is not an integer, but '%T'", type);
10673                         type = type_error_type;
10674                 }
10675                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10676                 rem_anchor_token(')');
10677                 expect(')', end_error);
10678                 statement->ms_try.final_statement = parse_compound_statement(false);
10679         } else if (token.type == T__finally) {
10680                 eat(T___finally);
10681                 statement->ms_try.final_statement = parse_compound_statement(false);
10682         } else {
10683                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10684                 return create_invalid_statement();
10685         }
10686         return statement;
10687 end_error:
10688         return create_invalid_statement();
10689 }
10690
10691 static statement_t *parse_empty_statement(void)
10692 {
10693         if (warning.empty_statement) {
10694                 warningf(HERE, "statement is empty");
10695         }
10696         statement_t *const statement = create_empty_statement();
10697         eat(';');
10698         return statement;
10699 }
10700
10701 static statement_t *parse_local_label_declaration(void)
10702 {
10703         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10704
10705         eat(T___label__);
10706
10707         entity_t *begin = NULL, *end = NULL;
10708
10709         while (true) {
10710                 if (token.type != T_IDENTIFIER) {
10711                         parse_error_expected("while parsing local label declaration",
10712                                 T_IDENTIFIER, NULL);
10713                         goto end_error;
10714                 }
10715                 symbol_t *symbol = token.v.symbol;
10716                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10717                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10718                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10719                                symbol, &entity->base.source_position);
10720                 } else {
10721                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10722
10723                         entity->base.parent_scope    = current_scope;
10724                         entity->base.namespc         = NAMESPACE_LABEL;
10725                         entity->base.source_position = token.source_position;
10726                         entity->base.symbol          = symbol;
10727
10728                         if (end != NULL)
10729                                 end->base.next = entity;
10730                         end = entity;
10731                         if (begin == NULL)
10732                                 begin = entity;
10733
10734                         environment_push(entity);
10735                 }
10736                 next_token();
10737
10738                 if (token.type != ',')
10739                         break;
10740                 next_token();
10741         }
10742         eat(';');
10743 end_error:
10744         statement->declaration.declarations_begin = begin;
10745         statement->declaration.declarations_end   = end;
10746         return statement;
10747 }
10748
10749 static void parse_namespace_definition(void)
10750 {
10751         eat(T_namespace);
10752
10753         entity_t *entity = NULL;
10754         symbol_t *symbol = NULL;
10755
10756         if (token.type == T_IDENTIFIER) {
10757                 symbol = token.v.symbol;
10758                 next_token();
10759
10760                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10761                 if (entity       != NULL             &&
10762                                 entity->kind != ENTITY_NAMESPACE &&
10763                                 entity->base.parent_scope == current_scope) {
10764                         if (!is_error_entity(entity)) {
10765                                 error_redefined_as_different_kind(&token.source_position,
10766                                                 entity, ENTITY_NAMESPACE);
10767                         }
10768                         entity = NULL;
10769                 }
10770         }
10771
10772         if (entity == NULL) {
10773                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10774                 entity->base.symbol          = symbol;
10775                 entity->base.source_position = token.source_position;
10776                 entity->base.namespc         = NAMESPACE_NORMAL;
10777                 entity->base.parent_scope    = current_scope;
10778         }
10779
10780         if (token.type == '=') {
10781                 /* TODO: parse namespace alias */
10782                 panic("namespace alias definition not supported yet");
10783         }
10784
10785         environment_push(entity);
10786         append_entity(current_scope, entity);
10787
10788         size_t const  top       = environment_top();
10789         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10790
10791         expect('{', end_error);
10792         parse_externals();
10793         expect('}', end_error);
10794
10795 end_error:
10796         assert(current_scope == &entity->namespacee.members);
10797         scope_pop(old_scope);
10798         environment_pop_to(top);
10799 }
10800
10801 /**
10802  * Parse a statement.
10803  * There's also parse_statement() which additionally checks for
10804  * "statement has no effect" warnings
10805  */
10806 static statement_t *intern_parse_statement(void)
10807 {
10808         statement_t *statement = NULL;
10809
10810         /* declaration or statement */
10811         add_anchor_token(';');
10812         switch (token.type) {
10813         case T_IDENTIFIER: {
10814                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10815                 if (la1_type == ':') {
10816                         statement = parse_label_statement();
10817                 } else if (is_typedef_symbol(token.v.symbol)) {
10818                         statement = parse_declaration_statement();
10819                 } else {
10820                         /* it's an identifier, the grammar says this must be an
10821                          * expression statement. However it is common that users mistype
10822                          * declaration types, so we guess a bit here to improve robustness
10823                          * for incorrect programs */
10824                         switch (la1_type) {
10825                         case '&':
10826                         case '*':
10827                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10828                                         goto expression_statment;
10829                                 /* FALLTHROUGH */
10830
10831                         DECLARATION_START
10832                         case T_IDENTIFIER:
10833                                 statement = parse_declaration_statement();
10834                                 break;
10835
10836                         default:
10837 expression_statment:
10838                                 statement = parse_expression_statement();
10839                                 break;
10840                         }
10841                 }
10842                 break;
10843         }
10844
10845         case T___extension__:
10846                 /* This can be a prefix to a declaration or an expression statement.
10847                  * We simply eat it now and parse the rest with tail recursion. */
10848                 do {
10849                         next_token();
10850                 } while (token.type == T___extension__);
10851                 bool old_gcc_extension = in_gcc_extension;
10852                 in_gcc_extension       = true;
10853                 statement = intern_parse_statement();
10854                 in_gcc_extension = old_gcc_extension;
10855                 break;
10856
10857         DECLARATION_START
10858                 statement = parse_declaration_statement();
10859                 break;
10860
10861         case T___label__:
10862                 statement = parse_local_label_declaration();
10863                 break;
10864
10865         case ';':         statement = parse_empty_statement();         break;
10866         case '{':         statement = parse_compound_statement(false); break;
10867         case T___leave:   statement = parse_leave_statement();         break;
10868         case T___try:     statement = parse_ms_try_statment();         break;
10869         case T_asm:       statement = parse_asm_statement();           break;
10870         case T_break:     statement = parse_break();                   break;
10871         case T_case:      statement = parse_case_statement();          break;
10872         case T_continue:  statement = parse_continue();                break;
10873         case T_default:   statement = parse_default_statement();       break;
10874         case T_do:        statement = parse_do();                      break;
10875         case T_for:       statement = parse_for();                     break;
10876         case T_goto:      statement = parse_goto();                    break;
10877         case T_if:        statement = parse_if();                      break;
10878         case T_return:    statement = parse_return();                  break;
10879         case T_switch:    statement = parse_switch();                  break;
10880         case T_while:     statement = parse_while();                   break;
10881
10882         EXPRESSION_START
10883                 statement = parse_expression_statement();
10884                 break;
10885
10886         default:
10887                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10888                 statement = create_invalid_statement();
10889                 if (!at_anchor())
10890                         next_token();
10891                 break;
10892         }
10893         rem_anchor_token(';');
10894
10895         assert(statement != NULL
10896                         && statement->base.source_position.input_name != NULL);
10897
10898         return statement;
10899 }
10900
10901 /**
10902  * parse a statement and emits "statement has no effect" warning if needed
10903  * (This is really a wrapper around intern_parse_statement with check for 1
10904  *  single warning. It is needed, because for statement expressions we have
10905  *  to avoid the warning on the last statement)
10906  */
10907 static statement_t *parse_statement(void)
10908 {
10909         statement_t *statement = intern_parse_statement();
10910
10911         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10912                 expression_t *expression = statement->expression.expression;
10913                 if (!expression_has_effect(expression)) {
10914                         warningf(&expression->base.source_position,
10915                                         "statement has no effect");
10916                 }
10917         }
10918
10919         return statement;
10920 }
10921
10922 /**
10923  * Parse a compound statement.
10924  */
10925 static statement_t *parse_compound_statement(bool inside_expression_statement)
10926 {
10927         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10928
10929         PUSH_PARENT(statement);
10930
10931         eat('{');
10932         add_anchor_token('}');
10933         /* tokens, which can start a statement */
10934         /* TODO MS, __builtin_FOO */
10935         add_anchor_token('!');
10936         add_anchor_token('&');
10937         add_anchor_token('(');
10938         add_anchor_token('*');
10939         add_anchor_token('+');
10940         add_anchor_token('-');
10941         add_anchor_token('{');
10942         add_anchor_token('~');
10943         add_anchor_token(T_CHARACTER_CONSTANT);
10944         add_anchor_token(T_COLONCOLON);
10945         add_anchor_token(T_FLOATINGPOINT);
10946         add_anchor_token(T_IDENTIFIER);
10947         add_anchor_token(T_INTEGER);
10948         add_anchor_token(T_MINUSMINUS);
10949         add_anchor_token(T_PLUSPLUS);
10950         add_anchor_token(T_STRING_LITERAL);
10951         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10952         add_anchor_token(T_WIDE_STRING_LITERAL);
10953         add_anchor_token(T__Bool);
10954         add_anchor_token(T__Complex);
10955         add_anchor_token(T__Imaginary);
10956         add_anchor_token(T___FUNCTION__);
10957         add_anchor_token(T___PRETTY_FUNCTION__);
10958         add_anchor_token(T___alignof__);
10959         add_anchor_token(T___attribute__);
10960         add_anchor_token(T___builtin_va_start);
10961         add_anchor_token(T___extension__);
10962         add_anchor_token(T___func__);
10963         add_anchor_token(T___imag__);
10964         add_anchor_token(T___label__);
10965         add_anchor_token(T___real__);
10966         add_anchor_token(T___thread);
10967         add_anchor_token(T_asm);
10968         add_anchor_token(T_auto);
10969         add_anchor_token(T_bool);
10970         add_anchor_token(T_break);
10971         add_anchor_token(T_case);
10972         add_anchor_token(T_char);
10973         add_anchor_token(T_class);
10974         add_anchor_token(T_const);
10975         add_anchor_token(T_const_cast);
10976         add_anchor_token(T_continue);
10977         add_anchor_token(T_default);
10978         add_anchor_token(T_delete);
10979         add_anchor_token(T_double);
10980         add_anchor_token(T_do);
10981         add_anchor_token(T_dynamic_cast);
10982         add_anchor_token(T_enum);
10983         add_anchor_token(T_extern);
10984         add_anchor_token(T_false);
10985         add_anchor_token(T_float);
10986         add_anchor_token(T_for);
10987         add_anchor_token(T_goto);
10988         add_anchor_token(T_if);
10989         add_anchor_token(T_inline);
10990         add_anchor_token(T_int);
10991         add_anchor_token(T_long);
10992         add_anchor_token(T_new);
10993         add_anchor_token(T_operator);
10994         add_anchor_token(T_register);
10995         add_anchor_token(T_reinterpret_cast);
10996         add_anchor_token(T_restrict);
10997         add_anchor_token(T_return);
10998         add_anchor_token(T_short);
10999         add_anchor_token(T_signed);
11000         add_anchor_token(T_sizeof);
11001         add_anchor_token(T_static);
11002         add_anchor_token(T_static_cast);
11003         add_anchor_token(T_struct);
11004         add_anchor_token(T_switch);
11005         add_anchor_token(T_template);
11006         add_anchor_token(T_this);
11007         add_anchor_token(T_throw);
11008         add_anchor_token(T_true);
11009         add_anchor_token(T_try);
11010         add_anchor_token(T_typedef);
11011         add_anchor_token(T_typeid);
11012         add_anchor_token(T_typename);
11013         add_anchor_token(T_typeof);
11014         add_anchor_token(T_union);
11015         add_anchor_token(T_unsigned);
11016         add_anchor_token(T_using);
11017         add_anchor_token(T_void);
11018         add_anchor_token(T_volatile);
11019         add_anchor_token(T_wchar_t);
11020         add_anchor_token(T_while);
11021
11022         size_t const  top       = environment_top();
11023         scope_t      *old_scope = scope_push(&statement->compound.scope);
11024
11025         statement_t **anchor            = &statement->compound.statements;
11026         bool          only_decls_so_far = true;
11027         while (token.type != '}') {
11028                 if (token.type == T_EOF) {
11029                         errorf(&statement->base.source_position,
11030                                "EOF while parsing compound statement");
11031                         break;
11032                 }
11033                 statement_t *sub_statement = intern_parse_statement();
11034                 if (is_invalid_statement(sub_statement)) {
11035                         /* an error occurred. if we are at an anchor, return */
11036                         if (at_anchor())
11037                                 goto end_error;
11038                         continue;
11039                 }
11040
11041                 if (warning.declaration_after_statement) {
11042                         if (sub_statement->kind != STATEMENT_DECLARATION) {
11043                                 only_decls_so_far = false;
11044                         } else if (!only_decls_so_far) {
11045                                 warningf(&sub_statement->base.source_position,
11046                                          "ISO C90 forbids mixed declarations and code");
11047                         }
11048                 }
11049
11050                 *anchor = sub_statement;
11051
11052                 while (sub_statement->base.next != NULL)
11053                         sub_statement = sub_statement->base.next;
11054
11055                 anchor = &sub_statement->base.next;
11056         }
11057         next_token();
11058
11059         /* look over all statements again to produce no effect warnings */
11060         if (warning.unused_value) {
11061                 statement_t *sub_statement = statement->compound.statements;
11062                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11063                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11064                                 continue;
11065                         /* don't emit a warning for the last expression in an expression
11066                          * statement as it has always an effect */
11067                         if (inside_expression_statement && sub_statement->base.next == NULL)
11068                                 continue;
11069
11070                         expression_t *expression = sub_statement->expression.expression;
11071                         if (!expression_has_effect(expression)) {
11072                                 warningf(&expression->base.source_position,
11073                                          "statement has no effect");
11074                         }
11075                 }
11076         }
11077
11078 end_error:
11079         rem_anchor_token(T_while);
11080         rem_anchor_token(T_wchar_t);
11081         rem_anchor_token(T_volatile);
11082         rem_anchor_token(T_void);
11083         rem_anchor_token(T_using);
11084         rem_anchor_token(T_unsigned);
11085         rem_anchor_token(T_union);
11086         rem_anchor_token(T_typeof);
11087         rem_anchor_token(T_typename);
11088         rem_anchor_token(T_typeid);
11089         rem_anchor_token(T_typedef);
11090         rem_anchor_token(T_try);
11091         rem_anchor_token(T_true);
11092         rem_anchor_token(T_throw);
11093         rem_anchor_token(T_this);
11094         rem_anchor_token(T_template);
11095         rem_anchor_token(T_switch);
11096         rem_anchor_token(T_struct);
11097         rem_anchor_token(T_static_cast);
11098         rem_anchor_token(T_static);
11099         rem_anchor_token(T_sizeof);
11100         rem_anchor_token(T_signed);
11101         rem_anchor_token(T_short);
11102         rem_anchor_token(T_return);
11103         rem_anchor_token(T_restrict);
11104         rem_anchor_token(T_reinterpret_cast);
11105         rem_anchor_token(T_register);
11106         rem_anchor_token(T_operator);
11107         rem_anchor_token(T_new);
11108         rem_anchor_token(T_long);
11109         rem_anchor_token(T_int);
11110         rem_anchor_token(T_inline);
11111         rem_anchor_token(T_if);
11112         rem_anchor_token(T_goto);
11113         rem_anchor_token(T_for);
11114         rem_anchor_token(T_float);
11115         rem_anchor_token(T_false);
11116         rem_anchor_token(T_extern);
11117         rem_anchor_token(T_enum);
11118         rem_anchor_token(T_dynamic_cast);
11119         rem_anchor_token(T_do);
11120         rem_anchor_token(T_double);
11121         rem_anchor_token(T_delete);
11122         rem_anchor_token(T_default);
11123         rem_anchor_token(T_continue);
11124         rem_anchor_token(T_const_cast);
11125         rem_anchor_token(T_const);
11126         rem_anchor_token(T_class);
11127         rem_anchor_token(T_char);
11128         rem_anchor_token(T_case);
11129         rem_anchor_token(T_break);
11130         rem_anchor_token(T_bool);
11131         rem_anchor_token(T_auto);
11132         rem_anchor_token(T_asm);
11133         rem_anchor_token(T___thread);
11134         rem_anchor_token(T___real__);
11135         rem_anchor_token(T___label__);
11136         rem_anchor_token(T___imag__);
11137         rem_anchor_token(T___func__);
11138         rem_anchor_token(T___extension__);
11139         rem_anchor_token(T___builtin_va_start);
11140         rem_anchor_token(T___attribute__);
11141         rem_anchor_token(T___alignof__);
11142         rem_anchor_token(T___PRETTY_FUNCTION__);
11143         rem_anchor_token(T___FUNCTION__);
11144         rem_anchor_token(T__Imaginary);
11145         rem_anchor_token(T__Complex);
11146         rem_anchor_token(T__Bool);
11147         rem_anchor_token(T_WIDE_STRING_LITERAL);
11148         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11149         rem_anchor_token(T_STRING_LITERAL);
11150         rem_anchor_token(T_PLUSPLUS);
11151         rem_anchor_token(T_MINUSMINUS);
11152         rem_anchor_token(T_INTEGER);
11153         rem_anchor_token(T_IDENTIFIER);
11154         rem_anchor_token(T_FLOATINGPOINT);
11155         rem_anchor_token(T_COLONCOLON);
11156         rem_anchor_token(T_CHARACTER_CONSTANT);
11157         rem_anchor_token('~');
11158         rem_anchor_token('{');
11159         rem_anchor_token('-');
11160         rem_anchor_token('+');
11161         rem_anchor_token('*');
11162         rem_anchor_token('(');
11163         rem_anchor_token('&');
11164         rem_anchor_token('!');
11165         rem_anchor_token('}');
11166         assert(current_scope == &statement->compound.scope);
11167         scope_pop(old_scope);
11168         environment_pop_to(top);
11169
11170         POP_PARENT;
11171         return statement;
11172 }
11173
11174 /**
11175  * Check for unused global static functions and variables
11176  */
11177 static void check_unused_globals(void)
11178 {
11179         if (!warning.unused_function && !warning.unused_variable)
11180                 return;
11181
11182         for (const entity_t *entity = file_scope->entities; entity != NULL;
11183              entity = entity->base.next) {
11184                 if (!is_declaration(entity))
11185                         continue;
11186
11187                 const declaration_t *declaration = &entity->declaration;
11188                 if (declaration->used                  ||
11189                     declaration->modifiers & DM_UNUSED ||
11190                     declaration->modifiers & DM_USED   ||
11191                     declaration->storage_class != STORAGE_CLASS_STATIC)
11192                         continue;
11193
11194                 type_t *const type = declaration->type;
11195                 const char *s;
11196                 if (entity->kind == ENTITY_FUNCTION) {
11197                         /* inhibit warning for static inline functions */
11198                         if (entity->function.is_inline)
11199                                 continue;
11200
11201                         s = entity->function.statement != NULL ? "defined" : "declared";
11202                 } else {
11203                         s = "defined";
11204                 }
11205
11206                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11207                         type, declaration->base.symbol, s);
11208         }
11209 }
11210
11211 static void parse_global_asm(void)
11212 {
11213         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11214
11215         eat(T_asm);
11216         expect('(', end_error);
11217
11218         statement->asms.asm_text = parse_string_literals();
11219         statement->base.next     = unit->global_asm;
11220         unit->global_asm         = statement;
11221
11222         expect(')', end_error);
11223         expect(';', end_error);
11224
11225 end_error:;
11226 }
11227
11228 static void parse_linkage_specification(void)
11229 {
11230         eat(T_extern);
11231         assert(token.type == T_STRING_LITERAL);
11232
11233         const char *linkage = parse_string_literals().begin;
11234
11235         linkage_kind_t old_linkage = current_linkage;
11236         linkage_kind_t new_linkage;
11237         if (strcmp(linkage, "C") == 0) {
11238                 new_linkage = LINKAGE_C;
11239         } else if (strcmp(linkage, "C++") == 0) {
11240                 new_linkage = LINKAGE_CXX;
11241         } else {
11242                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11243                 new_linkage = LINKAGE_INVALID;
11244         }
11245         current_linkage = new_linkage;
11246
11247         if (token.type == '{') {
11248                 next_token();
11249                 parse_externals();
11250                 expect('}', end_error);
11251         } else {
11252                 parse_external();
11253         }
11254
11255 end_error:
11256         assert(current_linkage == new_linkage);
11257         current_linkage = old_linkage;
11258 }
11259
11260 static void parse_external(void)
11261 {
11262         switch (token.type) {
11263                 DECLARATION_START_NO_EXTERN
11264                 case T_IDENTIFIER:
11265                 case T___extension__:
11266                 /* tokens below are for implicit int */
11267                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11268                              implicit int) */
11269                 case '*': /* * x; -> int* x; */
11270                 case '(': /* (x); -> int (x); */
11271                         parse_external_declaration();
11272                         return;
11273
11274                 case T_extern:
11275                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11276                                 parse_linkage_specification();
11277                         } else {
11278                                 parse_external_declaration();
11279                         }
11280                         return;
11281
11282                 case T_asm:
11283                         parse_global_asm();
11284                         return;
11285
11286                 case T_namespace:
11287                         parse_namespace_definition();
11288                         return;
11289
11290                 case ';':
11291                         if (!strict_mode) {
11292                                 if (warning.other)
11293                                         warningf(HERE, "stray ';' outside of function");
11294                                 next_token();
11295                                 return;
11296                         }
11297                         /* FALLTHROUGH */
11298
11299                 default:
11300                         errorf(HERE, "stray %K outside of function", &token);
11301                         if (token.type == '(' || token.type == '{' || token.type == '[')
11302                                 eat_until_matching_token(token.type);
11303                         next_token();
11304                         return;
11305         }
11306 }
11307
11308 static void parse_externals(void)
11309 {
11310         add_anchor_token('}');
11311         add_anchor_token(T_EOF);
11312
11313 #ifndef NDEBUG
11314         unsigned char token_anchor_copy[T_LAST_TOKEN];
11315         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11316 #endif
11317
11318         while (token.type != T_EOF && token.type != '}') {
11319 #ifndef NDEBUG
11320                 bool anchor_leak = false;
11321                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11322                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11323                         if (count != 0) {
11324                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11325                                 anchor_leak = true;
11326                         }
11327                 }
11328                 if (in_gcc_extension) {
11329                         errorf(HERE, "Leaked __extension__");
11330                         anchor_leak = true;
11331                 }
11332
11333                 if (anchor_leak)
11334                         abort();
11335 #endif
11336
11337                 parse_external();
11338         }
11339
11340         rem_anchor_token(T_EOF);
11341         rem_anchor_token('}');
11342 }
11343
11344 /**
11345  * Parse a translation unit.
11346  */
11347 static void parse_translation_unit(void)
11348 {
11349         add_anchor_token(T_EOF);
11350
11351         while (true) {
11352                 parse_externals();
11353
11354                 if (token.type == T_EOF)
11355                         break;
11356
11357                 errorf(HERE, "stray %K outside of function", &token);
11358                 if (token.type == '(' || token.type == '{' || token.type == '[')
11359                         eat_until_matching_token(token.type);
11360                 next_token();
11361         }
11362 }
11363
11364 /**
11365  * Parse the input.
11366  *
11367  * @return  the translation unit or NULL if errors occurred.
11368  */
11369 void start_parsing(void)
11370 {
11371         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11372         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11373         diagnostic_count  = 0;
11374         error_count       = 0;
11375         warning_count     = 0;
11376
11377         type_set_output(stderr);
11378         ast_set_output(stderr);
11379
11380         assert(unit == NULL);
11381         unit = allocate_ast_zero(sizeof(unit[0]));
11382
11383         assert(file_scope == NULL);
11384         file_scope = &unit->scope;
11385
11386         assert(current_scope == NULL);
11387         scope_push(&unit->scope);
11388
11389         create_gnu_builtins();
11390         if (c_mode & _MS)
11391                 create_microsoft_intrinsics();
11392 }
11393
11394 translation_unit_t *finish_parsing(void)
11395 {
11396         assert(current_scope == &unit->scope);
11397         scope_pop(NULL);
11398
11399         assert(file_scope == &unit->scope);
11400         check_unused_globals();
11401         file_scope = NULL;
11402
11403         DEL_ARR_F(environment_stack);
11404         DEL_ARR_F(label_stack);
11405
11406         translation_unit_t *result = unit;
11407         unit = NULL;
11408         return result;
11409 }
11410
11411 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
11412  * are given length one. */
11413 static void complete_incomplete_arrays(void)
11414 {
11415         size_t n = ARR_LEN(incomplete_arrays);
11416         for (size_t i = 0; i != n; ++i) {
11417                 declaration_t *const decl      = incomplete_arrays[i];
11418                 type_t        *const orig_type = decl->type;
11419                 type_t        *const type      = skip_typeref(orig_type);
11420
11421                 if (!is_type_incomplete(type))
11422                         continue;
11423
11424                 if (warning.other) {
11425                         warningf(&decl->base.source_position,
11426                                         "array '%#T' assumed to have one element",
11427                                         orig_type, decl->base.symbol);
11428                 }
11429
11430                 type_t *const new_type = duplicate_type(type);
11431                 new_type->array.size_constant     = true;
11432                 new_type->array.has_implicit_size = true;
11433                 new_type->array.size              = 1;
11434
11435                 type_t *const result = identify_new_type(new_type);
11436
11437                 decl->type = result;
11438         }
11439 }
11440
11441 void parse(void)
11442 {
11443         lookahead_bufpos = 0;
11444         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11445                 next_token();
11446         }
11447         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11448         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11449         parse_translation_unit();
11450         complete_incomplete_arrays();
11451         DEL_ARR_F(incomplete_arrays);
11452         incomplete_arrays = NULL;
11453 }
11454
11455 /**
11456  * create a builtin function.
11457  */
11458 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
11459 {
11460         symbol_t *symbol = symbol_table_insert(name);
11461         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
11462         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
11463         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
11464         entity->declaration.type                   = function_type;
11465         entity->declaration.implicit               = true;
11466         entity->base.symbol                        = symbol;
11467         entity->base.source_position               = builtin_source_position;
11468
11469         entity->function.btk                       = kind;
11470
11471         record_entity(entity, /*is_definition=*/false);
11472         return entity;
11473 }
11474
11475
11476 /**
11477  * Create predefined gnu builtins.
11478  */
11479 static void create_gnu_builtins(void)
11480 {
11481 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
11482
11483         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
11484         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
11485         GNU_BUILTIN(inf,            make_function_0_type(type_double));
11486         GNU_BUILTIN(inff,           make_function_0_type(type_float));
11487         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
11488         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
11489         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
11490         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
11491         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
11492         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
11493         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
11494         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
11495         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
11496         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
11497         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
11498         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
11499         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
11500         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
11501         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
11502
11503 #undef GNU_BUILTIN
11504 }
11505
11506 /**
11507  * Create predefined MS intrinsics.
11508  */
11509 static void create_microsoft_intrinsics(void)
11510 {
11511 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11512
11513         /* intrinsics for all architectures */
11514         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11515         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11516         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11517         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11518         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11519         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11520         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11521
11522         MS_BUILTIN(__debugbreak,            make_function_0_type(type_void));
11523         MS_BUILTIN(_ReturnAddress,          make_function_0_type(type_void_ptr));
11524         MS_BUILTIN(_AddressOfReturnAddress, make_function_0_type(type_void_ptr));
11525         MS_BUILTIN(__popcount,              make_function_1_type(type_unsigned_int, type_unsigned_int));
11526
11527         /* x86/x64 only */
11528         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11529         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11530         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11531         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11532         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11533         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11534         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11535         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11536         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11537         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11538         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11539         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11540         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11541
11542         if (machine_size <= 32) {
11543                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11544                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11545         } else {
11546                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11547                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11548         }
11549
11550 #undef MS_BUILTIN
11551 }
11552
11553 /**
11554  * Initialize the parser.
11555  */
11556 void init_parser(void)
11557 {
11558         sym_anonymous = symbol_table_insert("<anonymous>");
11559
11560         if (c_mode & _MS) {
11561                 /* add predefined symbols for extended-decl-modifier */
11562                 sym_align         = symbol_table_insert("align");
11563                 sym_allocate      = symbol_table_insert("allocate");
11564                 sym_dllimport     = symbol_table_insert("dllimport");
11565                 sym_dllexport     = symbol_table_insert("dllexport");
11566                 sym_naked         = symbol_table_insert("naked");
11567                 sym_noinline      = symbol_table_insert("noinline");
11568                 sym_returns_twice = symbol_table_insert("returns_twice");
11569                 sym_noreturn      = symbol_table_insert("noreturn");
11570                 sym_nothrow       = symbol_table_insert("nothrow");
11571                 sym_novtable      = symbol_table_insert("novtable");
11572                 sym_property      = symbol_table_insert("property");
11573                 sym_get           = symbol_table_insert("get");
11574                 sym_put           = symbol_table_insert("put");
11575                 sym_selectany     = symbol_table_insert("selectany");
11576                 sym_thread        = symbol_table_insert("thread");
11577                 sym_uuid          = symbol_table_insert("uuid");
11578                 sym_deprecated    = symbol_table_insert("deprecated");
11579                 sym_restrict      = symbol_table_insert("restrict");
11580                 sym_noalias       = symbol_table_insert("noalias");
11581         }
11582         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11583
11584         init_expression_parsers();
11585         obstack_init(&temp_obst);
11586
11587         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11588         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11589 }
11590
11591 /**
11592  * Terminate the parser.
11593  */
11594 void exit_parser(void)
11595 {
11596         obstack_free(&temp_obst, NULL);
11597 }