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