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                 if (symbol == NULL) {
3034                         assert(anonymous_entity == NULL);
3035                         anonymous_entity = (entity_t*)compound;
3036                 }
3037         }
3038
3039         compound->modifiers |= modifiers;
3040         return compound;
3041 }
3042
3043 static void parse_enum_entries(type_t *const enum_type)
3044 {
3045         eat('{');
3046
3047         if (token.type == '}') {
3048                 errorf(HERE, "empty enum not allowed");
3049                 next_token();
3050                 return;
3051         }
3052
3053         add_anchor_token('}');
3054         do {
3055                 if (token.type != T_IDENTIFIER) {
3056                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
3057                         eat_block();
3058                         rem_anchor_token('}');
3059                         return;
3060                 }
3061
3062                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
3063                 entity->enum_value.enum_type = enum_type;
3064                 entity->base.symbol          = token.v.symbol;
3065                 entity->base.source_position = token.source_position;
3066                 next_token();
3067
3068                 if (token.type == '=') {
3069                         next_token();
3070                         expression_t *value = parse_constant_expression();
3071
3072                         value = create_implicit_cast(value, enum_type);
3073                         entity->enum_value.value = value;
3074
3075                         /* TODO semantic */
3076                 }
3077
3078                 record_entity(entity, false);
3079
3080                 if (token.type != ',')
3081                         break;
3082                 next_token();
3083         } while (token.type != '}');
3084         rem_anchor_token('}');
3085
3086         expect('}', end_error);
3087
3088 end_error:
3089         ;
3090 }
3091
3092 static type_t *parse_enum_specifier(void)
3093 {
3094         gnu_attribute_t *attributes = NULL;
3095         entity_t        *entity;
3096         symbol_t        *symbol;
3097
3098         eat(T_enum);
3099         if (token.type == T_IDENTIFIER) {
3100                 symbol = token.v.symbol;
3101                 next_token();
3102
3103                 entity = get_entity(symbol, NAMESPACE_ENUM);
3104                 if (entity != NULL) {
3105                         assert(entity->kind == ENTITY_ENUM);
3106                         if (entity->base.parent_scope != current_scope &&
3107                                         (token.type == '{' || token.type == ';')) {
3108                                 /* we're in an inner scope and have a definition. Shadow
3109                                  * existing definition in outer scope */
3110                                 entity = NULL;
3111                         } else if (entity->enume.complete && token.type == '{') {
3112                                 errorf(HERE, "multiple definitions of 'enum %Y' (previous definition %P)",
3113                                                 symbol, &entity->base.source_position);
3114                         }
3115                 }
3116         } else if (token.type != '{') {
3117                 parse_error_expected("while parsing enum type specifier",
3118                                      T_IDENTIFIER, '{', NULL);
3119                 return NULL;
3120         } else {
3121                 entity  = NULL;
3122                 symbol  = NULL;
3123         }
3124
3125         if (entity == NULL) {
3126                 entity                       = allocate_entity_zero(ENTITY_ENUM);
3127                 entity->base.namespc         = NAMESPACE_ENUM;
3128                 entity->base.source_position = token.source_position;
3129                 entity->base.symbol          = symbol;
3130                 entity->base.parent_scope    = current_scope;
3131         }
3132
3133         type_t *const type = allocate_type_zero(TYPE_ENUM);
3134         type->enumt.enume  = &entity->enume;
3135         type->enumt.akind  = ATOMIC_TYPE_INT;
3136
3137         if (token.type == '{') {
3138                 if (symbol != NULL) {
3139                         environment_push(entity);
3140                 }
3141                 append_entity(current_scope, entity);
3142                 entity->enume.complete = true;
3143
3144                 parse_enum_entries(type);
3145                 parse_attributes(&attributes);
3146
3147                 if (symbol == NULL) {
3148                         assert(anonymous_entity == NULL);
3149                         anonymous_entity = entity;
3150                 }
3151         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
3152                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
3153                        symbol);
3154         }
3155
3156         return type;
3157 }
3158
3159 /**
3160  * if a symbol is a typedef to another type, return true
3161  */
3162 static bool is_typedef_symbol(symbol_t *symbol)
3163 {
3164         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
3165         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
3166 }
3167
3168 static type_t *parse_typeof(void)
3169 {
3170         eat(T___typeof__);
3171
3172         type_t *type;
3173
3174         expect('(', end_error);
3175         add_anchor_token(')');
3176
3177         expression_t *expression  = NULL;
3178
3179         bool old_type_prop     = in_type_prop;
3180         bool old_gcc_extension = in_gcc_extension;
3181         in_type_prop           = true;
3182
3183         while (token.type == T___extension__) {
3184                 /* This can be a prefix to a typename or an expression. */
3185                 next_token();
3186                 in_gcc_extension = true;
3187         }
3188         switch (token.type) {
3189         case T_IDENTIFIER:
3190                 if (is_typedef_symbol(token.v.symbol)) {
3191                         type = parse_typename();
3192                 } else {
3193                         expression = parse_expression();
3194                         type       = revert_automatic_type_conversion(expression);
3195                 }
3196                 break;
3197
3198         TYPENAME_START
3199                 type = parse_typename();
3200                 break;
3201
3202         default:
3203                 expression = parse_expression();
3204                 type       = expression->base.type;
3205                 break;
3206         }
3207         in_type_prop     = old_type_prop;
3208         in_gcc_extension = old_gcc_extension;
3209
3210         rem_anchor_token(')');
3211         expect(')', end_error);
3212
3213         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
3214         typeof_type->typeoft.expression  = expression;
3215         typeof_type->typeoft.typeof_type = type;
3216
3217         return typeof_type;
3218 end_error:
3219         return NULL;
3220 }
3221
3222 typedef enum specifiers_t {
3223         SPECIFIER_SIGNED    = 1 << 0,
3224         SPECIFIER_UNSIGNED  = 1 << 1,
3225         SPECIFIER_LONG      = 1 << 2,
3226         SPECIFIER_INT       = 1 << 3,
3227         SPECIFIER_DOUBLE    = 1 << 4,
3228         SPECIFIER_CHAR      = 1 << 5,
3229         SPECIFIER_WCHAR_T   = 1 << 6,
3230         SPECIFIER_SHORT     = 1 << 7,
3231         SPECIFIER_LONG_LONG = 1 << 8,
3232         SPECIFIER_FLOAT     = 1 << 9,
3233         SPECIFIER_BOOL      = 1 << 10,
3234         SPECIFIER_VOID      = 1 << 11,
3235         SPECIFIER_INT8      = 1 << 12,
3236         SPECIFIER_INT16     = 1 << 13,
3237         SPECIFIER_INT32     = 1 << 14,
3238         SPECIFIER_INT64     = 1 << 15,
3239         SPECIFIER_INT128    = 1 << 16,
3240         SPECIFIER_COMPLEX   = 1 << 17,
3241         SPECIFIER_IMAGINARY = 1 << 18,
3242 } specifiers_t;
3243
3244 static type_t *create_builtin_type(symbol_t *const symbol,
3245                                    type_t *const real_type)
3246 {
3247         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
3248         type->builtin.symbol    = symbol;
3249         type->builtin.real_type = real_type;
3250         return identify_new_type(type);
3251 }
3252
3253 static type_t *get_typedef_type(symbol_t *symbol)
3254 {
3255         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3256         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
3257                 return NULL;
3258
3259         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
3260         type->typedeft.typedefe = &entity->typedefe;
3261
3262         return type;
3263 }
3264
3265 /**
3266  * check for the allowed MS alignment values.
3267  */
3268 static bool check_alignment_value(long long intvalue)
3269 {
3270         if (intvalue < 1 || intvalue > 8192) {
3271                 errorf(HERE, "illegal alignment value");
3272                 return false;
3273         }
3274         unsigned v = (unsigned)intvalue;
3275         for (unsigned i = 1; i <= 8192; i += i) {
3276                 if (i == v)
3277                         return true;
3278         }
3279         errorf(HERE, "alignment must be power of two");
3280         return false;
3281 }
3282
3283 #define DET_MOD(name, tag) do { \
3284         if (*modifiers & tag && warning.other) warningf(HERE, #name " used more than once"); \
3285         *modifiers |= tag; \
3286 } while (0)
3287
3288 static void parse_microsoft_extended_decl_modifier(declaration_specifiers_t *specifiers)
3289 {
3290         decl_modifiers_t *modifiers = &specifiers->modifiers;
3291
3292         while (true) {
3293                 if (token.type == T_restrict) {
3294                         next_token();
3295                         DET_MOD(restrict, DM_RESTRICT);
3296                         goto end_loop;
3297                 } else if (token.type != T_IDENTIFIER)
3298                         break;
3299                 symbol_t *symbol = token.v.symbol;
3300                 if (symbol == sym_align) {
3301                         next_token();
3302                         expect('(', end_error);
3303                         if (token.type != T_INTEGER)
3304                                 goto end_error;
3305                         if (check_alignment_value(token.v.intvalue)) {
3306                                 if (specifiers->alignment != 0 && warning.other)
3307                                         warningf(HERE, "align used more than once");
3308                                 specifiers->alignment = (unsigned char)token.v.intvalue;
3309                         }
3310                         next_token();
3311                         expect(')', end_error);
3312                 } else if (symbol == sym_allocate) {
3313                         next_token();
3314                         expect('(', end_error);
3315                         if (token.type != T_IDENTIFIER)
3316                                 goto end_error;
3317                         (void)token.v.symbol;
3318                         expect(')', end_error);
3319                 } else if (symbol == sym_dllimport) {
3320                         next_token();
3321                         DET_MOD(dllimport, DM_DLLIMPORT);
3322                 } else if (symbol == sym_dllexport) {
3323                         next_token();
3324                         DET_MOD(dllexport, DM_DLLEXPORT);
3325                 } else if (symbol == sym_thread) {
3326                         next_token();
3327                         DET_MOD(thread, DM_THREAD);
3328                 } else if (symbol == sym_naked) {
3329                         next_token();
3330                         DET_MOD(naked, DM_NAKED);
3331                 } else if (symbol == sym_noinline) {
3332                         next_token();
3333                         DET_MOD(noinline, DM_NOINLINE);
3334                 } else if (symbol == sym_returns_twice) {
3335                         next_token();
3336                         DET_MOD(returns_twice, DM_RETURNS_TWICE);
3337                 } else if (symbol == sym_noreturn) {
3338                         next_token();
3339                         DET_MOD(noreturn, DM_NORETURN);
3340                 } else if (symbol == sym_nothrow) {
3341                         next_token();
3342                         DET_MOD(nothrow, DM_NOTHROW);
3343                 } else if (symbol == sym_novtable) {
3344                         next_token();
3345                         DET_MOD(novtable, DM_NOVTABLE);
3346                 } else if (symbol == sym_property) {
3347                         next_token();
3348                         expect('(', end_error);
3349                         for (;;) {
3350                                 bool is_get = false;
3351                                 if (token.type != T_IDENTIFIER)
3352                                         goto end_error;
3353                                 if (token.v.symbol == sym_get) {
3354                                         is_get = true;
3355                                 } else if (token.v.symbol == sym_put) {
3356                                 } else {
3357                                         errorf(HERE, "Bad property name '%Y'", token.v.symbol);
3358                                         goto end_error;
3359                                 }
3360                                 next_token();
3361                                 expect('=', end_error);
3362                                 if (token.type != T_IDENTIFIER)
3363                                         goto end_error;
3364                                 if (is_get) {
3365                                         if (specifiers->get_property_sym != NULL) {
3366                                                 errorf(HERE, "get property name already specified");
3367                                         } else {
3368                                                 specifiers->get_property_sym = token.v.symbol;
3369                                         }
3370                                 } else {
3371                                         if (specifiers->put_property_sym != NULL) {
3372                                                 errorf(HERE, "put property name already specified");
3373                                         } else {
3374                                                 specifiers->put_property_sym = token.v.symbol;
3375                                         }
3376                                 }
3377                                 next_token();
3378                                 if (token.type == ',') {
3379                                         next_token();
3380                                         continue;
3381                                 }
3382                                 break;
3383                         }
3384                         expect(')', end_error);
3385                 } else if (symbol == sym_selectany) {
3386                         next_token();
3387                         DET_MOD(selectany, DM_SELECTANY);
3388                 } else if (symbol == sym_uuid) {
3389                         next_token();
3390                         expect('(', end_error);
3391                         if (token.type != T_STRING_LITERAL)
3392                                 goto end_error;
3393                         next_token();
3394                         expect(')', end_error);
3395                 } else if (symbol == sym_deprecated) {
3396                         next_token();
3397                         if (specifiers->deprecated != 0 && warning.other)
3398                                 warningf(HERE, "deprecated used more than once");
3399                         specifiers->deprecated = true;
3400                         if (token.type == '(') {
3401                                 next_token();
3402                                 if (token.type == T_STRING_LITERAL) {
3403                                         specifiers->deprecated_string = token.v.string.begin;
3404                                         next_token();
3405                                 } else {
3406                                         errorf(HERE, "string literal expected");
3407                                 }
3408                                 expect(')', end_error);
3409                         }
3410                 } else if (symbol == sym_noalias) {
3411                         next_token();
3412                         DET_MOD(noalias, DM_NOALIAS);
3413                 } else {
3414                         if (warning.other)
3415                                 warningf(HERE, "Unknown modifier '%Y' ignored", token.v.symbol);
3416                         next_token();
3417                         if (token.type == '(')
3418                                 skip_until(')');
3419                 }
3420 end_loop:
3421                 if (token.type == ',')
3422                         next_token();
3423         }
3424 end_error:
3425         return;
3426 }
3427
3428 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
3429 {
3430         entity_t *entity             = allocate_entity_zero(kind);
3431         entity->base.source_position = *HERE;
3432         entity->base.symbol          = symbol;
3433         if (is_declaration(entity)) {
3434                 entity->declaration.type     = type_error_type;
3435                 entity->declaration.implicit = true;
3436         } else if (kind == ENTITY_TYPEDEF) {
3437                 entity->typedefe.type    = type_error_type;
3438                 entity->typedefe.builtin = true;
3439         }
3440         if (kind != ENTITY_COMPOUND_MEMBER)
3441                 record_entity(entity, false);
3442         return entity;
3443 }
3444
3445 static variable_t *parse_microsoft_based(void)
3446 {
3447         if (token.type != T_IDENTIFIER) {
3448                 parse_error_expected("while parsing __based", T_IDENTIFIER, NULL);
3449                 return NULL;
3450         }
3451         symbol_t *symbol = token.v.symbol;
3452         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
3453
3454         variable_t *variable;
3455         if (entity == NULL || entity->base.kind != ENTITY_VARIABLE) {
3456                 errorf(HERE, "'%Y' is not a variable name.", symbol);
3457                 variable = &create_error_entity(symbol, ENTITY_VARIABLE)->variable;
3458         } else {
3459                 variable = &entity->variable;
3460
3461                 type_t *const type = variable->base.type;
3462                 if (is_type_valid(type)) {
3463                         if (! is_type_pointer(skip_typeref(type))) {
3464                                 errorf(HERE, "variable in __based modifier must have pointer type instead of '%T'", type);
3465                         }
3466                         if (variable->base.base.parent_scope != file_scope) {
3467                                 errorf(HERE, "a nonstatic local variable may not be used in a __based specification");
3468                         }
3469                 }
3470         }
3471         next_token();
3472         return variable;
3473 }
3474
3475 /**
3476  * Finish the construction of a struct type by calculating
3477  * its size, offsets, alignment.
3478  */
3479 static void finish_struct_type(compound_type_t *type)
3480 {
3481         assert(type->compound != NULL);
3482
3483         compound_t *compound = type->compound;
3484         if (!compound->complete)
3485                 return;
3486
3487         il_size_t      size           = 0;
3488         il_size_t      offset;
3489         il_alignment_t alignment      = 1;
3490         bool           need_pad       = false;
3491
3492         entity_t *entry = compound->members.entities;
3493         for (; entry != NULL; entry = entry->base.next) {
3494                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3495                         continue;
3496
3497                 type_t *m_type = skip_typeref(entry->declaration.type);
3498                 if (! is_type_valid(m_type)) {
3499                         /* simply ignore errors here */
3500                         continue;
3501                 }
3502                 il_alignment_t m_alignment = m_type->base.alignment;
3503                 if (m_alignment > alignment)
3504                         alignment = m_alignment;
3505
3506                 offset = (size + m_alignment - 1) & -m_alignment;
3507
3508                 if (offset > size)
3509                         need_pad = true;
3510                 entry->compound_member.offset = offset;
3511                 size = offset + m_type->base.size;
3512         }
3513         if (type->base.alignment != 0) {
3514                 alignment = type->base.alignment;
3515         }
3516
3517         offset = (size + alignment - 1) & -alignment;
3518         if (offset > size)
3519                 need_pad = true;
3520
3521         if (need_pad) {
3522                 if (warning.padded) {
3523                         warningf(&compound->base.source_position, "'%T' needs padding", type);
3524                 }
3525         } else {
3526                 if (compound->modifiers & DM_PACKED && warning.packed) {
3527                         warningf(&compound->base.source_position,
3528                                         "superfluous packed attribute on '%T'", type);
3529                 }
3530         }
3531
3532         type->base.size      = offset;
3533         type->base.alignment = alignment;
3534 }
3535
3536 /**
3537  * Finish the construction of an union type by calculating
3538  * its size and alignment.
3539  */
3540 static void finish_union_type(compound_type_t *type)
3541 {
3542         assert(type->compound != NULL);
3543
3544         compound_t *compound = type->compound;
3545         if (! compound->complete)
3546                 return;
3547
3548         il_size_t      size      = 0;
3549         il_alignment_t alignment = 1;
3550
3551         entity_t *entry = compound->members.entities;
3552         for (; entry != NULL; entry = entry->base.next) {
3553                 if (entry->kind != ENTITY_COMPOUND_MEMBER)
3554                         continue;
3555
3556                 type_t *m_type = skip_typeref(entry->declaration.type);
3557                 if (! is_type_valid(m_type))
3558                         continue;
3559
3560                 entry->compound_member.offset = 0;
3561                 if (m_type->base.size > size)
3562                         size = m_type->base.size;
3563                 if (m_type->base.alignment > alignment)
3564                         alignment = m_type->base.alignment;
3565         }
3566         if (type->base.alignment != 0) {
3567                 alignment = type->base.alignment;
3568         }
3569         size = (size + alignment - 1) & -alignment;
3570         type->base.size      = size;
3571         type->base.alignment = alignment;
3572 }
3573
3574 static type_t *handle_attribute_mode(const gnu_attribute_t *attribute,
3575                                      type_t *orig_type)
3576 {
3577         type_t *type = skip_typeref(orig_type);
3578
3579         /* at least: byte, word, pointer, list of machine modes
3580          * __XXX___ is interpreted as XXX */
3581
3582         /* This isn't really correct, the backend should provide a list of machine
3583          * specific modes (according to gcc philosophy that is...) */
3584         const char         *symbol_str = attribute->u.symbol->string;
3585         bool                sign       = is_type_signed(type);
3586         atomic_type_kind_t  akind;
3587         if (strcmp_underscore("QI",   symbol_str) == 0 ||
3588             strcmp_underscore("byte", symbol_str) == 0) {
3589                 akind = sign ? ATOMIC_TYPE_CHAR : ATOMIC_TYPE_UCHAR;
3590         } else if (strcmp_underscore("HI", symbol_str) == 0) {
3591                 akind = sign ? ATOMIC_TYPE_SHORT : ATOMIC_TYPE_USHORT;
3592         } else if (strcmp_underscore("SI",      symbol_str) == 0
3593                 || strcmp_underscore("word",    symbol_str) == 0
3594                 || strcmp_underscore("pointer", symbol_str) == 0) {
3595                 akind = sign ? ATOMIC_TYPE_INT : ATOMIC_TYPE_UINT;
3596         } else if (strcmp_underscore("DI", symbol_str) == 0) {
3597                 akind = sign ? ATOMIC_TYPE_LONGLONG : ATOMIC_TYPE_ULONGLONG;
3598         } else {
3599                 if (warning.other)
3600                         warningf(HERE, "ignoring unknown mode '%s'", symbol_str);
3601                 return orig_type;
3602         }
3603
3604         if (type->kind == TYPE_ATOMIC) {
3605                 type_t *copy       = duplicate_type(type);
3606                 copy->atomic.akind = akind;
3607                 return identify_new_type(copy);
3608         } else if (type->kind == TYPE_ENUM) {
3609                 type_t *copy      = duplicate_type(type);
3610                 copy->enumt.akind = akind;
3611                 return identify_new_type(copy);
3612         } else if (is_type_pointer(type)) {
3613                 warningf(HERE, "__attribute__((mode)) on pointers not implemented yet (ignored)");
3614                 return type;
3615         }
3616
3617         errorf(HERE, "__attribute__((mode)) only allowed on integer, enum or pointer type");
3618         return orig_type;
3619 }
3620
3621 static type_t *handle_type_attributes(const gnu_attribute_t *attributes,
3622                                       type_t *type)
3623 {
3624         const gnu_attribute_t *attribute = attributes;
3625         for ( ; attribute != NULL; attribute = attribute->next) {
3626                 if (attribute->invalid)
3627                         continue;
3628
3629                 if (attribute->kind == GNU_AK_MODE) {
3630                         type = handle_attribute_mode(attribute, type);
3631                 } else if (attribute->kind == GNU_AK_ALIGNED) {
3632                         int alignment = 32; /* TODO: fill in maximum useful alignment for
3633                                                target machine */
3634                         if (attribute->has_arguments)
3635                                 alignment = attribute->u.argument;
3636
3637                         type_t *copy         = duplicate_type(type);
3638                         copy->base.alignment = attribute->u.argument;
3639                         type                 = identify_new_type(copy);
3640                 }
3641         }
3642
3643         return type;
3644 }
3645
3646 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
3647 {
3648         type_t            *type              = NULL;
3649         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
3650         type_modifiers_t   modifiers         = TYPE_MODIFIER_NONE;
3651         unsigned           type_specifiers   = 0;
3652         bool               newtype           = false;
3653         bool               saw_error         = false;
3654         bool               old_gcc_extension = in_gcc_extension;
3655
3656         specifiers->source_position = token.source_position;
3657
3658         while (true) {
3659                 specifiers->modifiers
3660                         |= parse_attributes(&specifiers->gnu_attributes);
3661
3662                 switch (token.type) {
3663                 /* storage class */
3664 #define MATCH_STORAGE_CLASS(token, class)                                  \
3665                 case token:                                                        \
3666                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
3667                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
3668                         }                                                              \
3669                         specifiers->storage_class = class;                             \
3670                         if (specifiers->thread_local)                                  \
3671                                 goto check_thread_storage_class;                           \
3672                         next_token();                                                  \
3673                         break;
3674
3675                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
3676                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
3677                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
3678                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
3679                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
3680
3681                 case T__declspec:
3682                         next_token();
3683                         expect('(', end_error);
3684                         add_anchor_token(')');
3685                         parse_microsoft_extended_decl_modifier(specifiers);
3686                         rem_anchor_token(')');
3687                         expect(')', end_error);
3688                         break;
3689
3690                 case T___thread:
3691                         if (specifiers->thread_local) {
3692                                 errorf(HERE, "duplicate '__thread'");
3693                         } else {
3694                                 specifiers->thread_local = true;
3695 check_thread_storage_class:
3696                                 switch (specifiers->storage_class) {
3697                                         case STORAGE_CLASS_EXTERN:
3698                                         case STORAGE_CLASS_NONE:
3699                                         case STORAGE_CLASS_STATIC:
3700                                                 break;
3701
3702                                                 char const* wrong;
3703                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_stoarge_class;
3704                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_stoarge_class;
3705                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_stoarge_class;
3706 wrong_thread_stoarge_class:
3707                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
3708                                                 break;
3709                                 }
3710                         }
3711                         next_token();
3712                         break;
3713
3714                 /* type qualifiers */
3715 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
3716                 case token:                                                     \
3717                         qualifiers |= qualifier;                                    \
3718                         next_token();                                               \
3719                         break
3720
3721                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3722                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3723                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3724                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3725                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3726                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3727                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3728                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3729
3730                 case T___extension__:
3731                         next_token();
3732                         in_gcc_extension = true;
3733                         break;
3734
3735                 /* type specifiers */
3736 #define MATCH_SPECIFIER(token, specifier, name)                         \
3737                 case token:                                                     \
3738                         if (type_specifiers & specifier) {                           \
3739                                 errorf(HERE, "multiple " name " type specifiers given"); \
3740                         } else {                                                    \
3741                                 type_specifiers |= specifier;                           \
3742                         }                                                           \
3743                         next_token();                                               \
3744                         break
3745
3746                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
3747                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
3748                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
3749                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
3750                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
3751                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
3752                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
3753                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
3754                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
3755                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
3756                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
3757                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
3758                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
3759                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
3760                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
3761                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
3762                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
3763                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
3764
3765                 case T__forceinline:
3766                         /* only in microsoft mode */
3767                         specifiers->modifiers |= DM_FORCEINLINE;
3768                         /* FALLTHROUGH */
3769
3770                 case T_inline:
3771                         next_token();
3772                         specifiers->is_inline = true;
3773                         break;
3774
3775                 case T_long:
3776                         if (type_specifiers & SPECIFIER_LONG_LONG) {
3777                                 errorf(HERE, "multiple type specifiers given");
3778                         } else if (type_specifiers & SPECIFIER_LONG) {
3779                                 type_specifiers |= SPECIFIER_LONG_LONG;
3780                         } else {
3781                                 type_specifiers |= SPECIFIER_LONG;
3782                         }
3783                         next_token();
3784                         break;
3785
3786                 case T_struct: {
3787                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
3788
3789                         type->compound.compound = parse_compound_type_specifier(true);
3790                         finish_struct_type(&type->compound);
3791                         break;
3792                 }
3793                 case T_union: {
3794                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
3795                         type->compound.compound = parse_compound_type_specifier(false);
3796                         if (type->compound.compound->modifiers & DM_TRANSPARENT_UNION)
3797                                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
3798                         finish_union_type(&type->compound);
3799                         break;
3800                 }
3801                 case T_enum:
3802                         type = parse_enum_specifier();
3803                         break;
3804                 case T___typeof__:
3805                         type = parse_typeof();
3806                         break;
3807                 case T___builtin_va_list:
3808                         type = duplicate_type(type_valist);
3809                         next_token();
3810                         break;
3811
3812                 case T_IDENTIFIER: {
3813                         /* only parse identifier if we haven't found a type yet */
3814                         if (type != NULL || type_specifiers != 0) {
3815                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3816                                  * declaration, so it doesn't generate errors about expecting '(' or
3817                                  * '{' later on. */
3818                                 switch (look_ahead(1)->type) {
3819                                         STORAGE_CLASSES
3820                                         TYPE_SPECIFIERS
3821                                         case T_const:
3822                                         case T_restrict:
3823                                         case T_volatile:
3824                                         case T_inline:
3825                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3826                                         case T_IDENTIFIER:
3827                                         case '&':
3828                                         case '*':
3829                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3830                                                 next_token();
3831                                                 continue;
3832
3833                                         default:
3834                                                 goto finish_specifiers;
3835                                 }
3836                         }
3837
3838                         type_t *const typedef_type = get_typedef_type(token.v.symbol);
3839                         if (typedef_type == NULL) {
3840                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3841                                  * declaration, so it doesn't generate 'implicit int' followed by more
3842                                  * errors later on. */
3843                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3844                                 switch (la1_type) {
3845                                         DECLARATION_START
3846                                         case T_IDENTIFIER:
3847                                         case '&':
3848                                         case '*': {
3849                                                 errorf(HERE, "%K does not name a type", &token);
3850
3851                                                 entity_t *entity =
3852                                                         create_error_entity(token.v.symbol, ENTITY_TYPEDEF);
3853
3854                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3855                                                 type->typedeft.typedefe = &entity->typedefe;
3856
3857                                                 next_token();
3858                                                 saw_error = true;
3859                                                 if (la1_type == '&' || la1_type == '*')
3860                                                         goto finish_specifiers;
3861                                                 continue;
3862                                         }
3863
3864                                         default:
3865                                                 goto finish_specifiers;
3866                                 }
3867                         }
3868
3869                         next_token();
3870                         type = typedef_type;
3871                         break;
3872                 }
3873
3874                 /* function specifier */
3875                 default:
3876                         goto finish_specifiers;
3877                 }
3878         }
3879
3880 finish_specifiers:
3881         specifiers->modifiers
3882                 |= parse_attributes(&specifiers->gnu_attributes);
3883
3884         in_gcc_extension = old_gcc_extension;
3885
3886         if (type == NULL || (saw_error && type_specifiers != 0)) {
3887                 atomic_type_kind_t atomic_type;
3888
3889                 /* match valid basic types */
3890                 switch (type_specifiers) {
3891                 case SPECIFIER_VOID:
3892                         atomic_type = ATOMIC_TYPE_VOID;
3893                         break;
3894                 case SPECIFIER_WCHAR_T:
3895                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3896                         break;
3897                 case SPECIFIER_CHAR:
3898                         atomic_type = ATOMIC_TYPE_CHAR;
3899                         break;
3900                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3901                         atomic_type = ATOMIC_TYPE_SCHAR;
3902                         break;
3903                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3904                         atomic_type = ATOMIC_TYPE_UCHAR;
3905                         break;
3906                 case SPECIFIER_SHORT:
3907                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3908                 case SPECIFIER_SHORT | SPECIFIER_INT:
3909                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3910                         atomic_type = ATOMIC_TYPE_SHORT;
3911                         break;
3912                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3913                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3914                         atomic_type = ATOMIC_TYPE_USHORT;
3915                         break;
3916                 case SPECIFIER_INT:
3917                 case SPECIFIER_SIGNED:
3918                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3919                         atomic_type = ATOMIC_TYPE_INT;
3920                         break;
3921                 case SPECIFIER_UNSIGNED:
3922                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3923                         atomic_type = ATOMIC_TYPE_UINT;
3924                         break;
3925                 case SPECIFIER_LONG:
3926                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3927                 case SPECIFIER_LONG | SPECIFIER_INT:
3928                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3929                         atomic_type = ATOMIC_TYPE_LONG;
3930                         break;
3931                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3932                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3933                         atomic_type = ATOMIC_TYPE_ULONG;
3934                         break;
3935
3936                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3937                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3938                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3939                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3940                         | SPECIFIER_INT:
3941                         atomic_type = ATOMIC_TYPE_LONGLONG;
3942                         goto warn_about_long_long;
3943
3944                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3945                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3946                         | SPECIFIER_INT:
3947                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3948 warn_about_long_long:
3949                         if (warning.long_long) {
3950                                 warningf(&specifiers->source_position,
3951                                          "ISO C90 does not support 'long long'");
3952                         }
3953                         break;
3954
3955                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3956                         atomic_type = unsigned_int8_type_kind;
3957                         break;
3958
3959                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3960                         atomic_type = unsigned_int16_type_kind;
3961                         break;
3962
3963                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3964                         atomic_type = unsigned_int32_type_kind;
3965                         break;
3966
3967                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3968                         atomic_type = unsigned_int64_type_kind;
3969                         break;
3970
3971                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3972                         atomic_type = unsigned_int128_type_kind;
3973                         break;
3974
3975                 case SPECIFIER_INT8:
3976                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3977                         atomic_type = int8_type_kind;
3978                         break;
3979
3980                 case SPECIFIER_INT16:
3981                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3982                         atomic_type = int16_type_kind;
3983                         break;
3984
3985                 case SPECIFIER_INT32:
3986                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3987                         atomic_type = int32_type_kind;
3988                         break;
3989
3990                 case SPECIFIER_INT64:
3991                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3992                         atomic_type = int64_type_kind;
3993                         break;
3994
3995                 case SPECIFIER_INT128:
3996                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3997                         atomic_type = int128_type_kind;
3998                         break;
3999
4000                 case SPECIFIER_FLOAT:
4001                         atomic_type = ATOMIC_TYPE_FLOAT;
4002                         break;
4003                 case SPECIFIER_DOUBLE:
4004                         atomic_type = ATOMIC_TYPE_DOUBLE;
4005                         break;
4006                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
4007                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4008                         break;
4009                 case SPECIFIER_BOOL:
4010                         atomic_type = ATOMIC_TYPE_BOOL;
4011                         break;
4012                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
4013                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
4014                         atomic_type = ATOMIC_TYPE_FLOAT;
4015                         break;
4016                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4017                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4018                         atomic_type = ATOMIC_TYPE_DOUBLE;
4019                         break;
4020                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
4021                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
4022                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
4023                         break;
4024                 default:
4025                         /* invalid specifier combination, give an error message */
4026                         if (type_specifiers == 0) {
4027                                 if (saw_error)
4028                                         goto end_error;
4029
4030                                 /* ISO/IEC 14882:1998(E) §C.1.5:4 */
4031                                 if (!(c_mode & _CXX) && !strict_mode) {
4032                                         if (warning.implicit_int) {
4033                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
4034                                         }
4035                                         atomic_type = ATOMIC_TYPE_INT;
4036                                         break;
4037                                 } else {
4038                                         errorf(HERE, "no type specifiers given in declaration");
4039                                 }
4040                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
4041                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
4042                                 errorf(HERE, "signed and unsigned specifiers given");
4043                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
4044                                 errorf(HERE, "only integer types can be signed or unsigned");
4045                         } else {
4046                                 errorf(HERE, "multiple datatypes in declaration");
4047                         }
4048                         goto end_error;
4049                 }
4050
4051                 if (type_specifiers & SPECIFIER_COMPLEX) {
4052                         type                = allocate_type_zero(TYPE_COMPLEX);
4053                         type->complex.akind = atomic_type;
4054                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
4055                         type                  = allocate_type_zero(TYPE_IMAGINARY);
4056                         type->imaginary.akind = atomic_type;
4057                 } else {
4058                         type                 = allocate_type_zero(TYPE_ATOMIC);
4059                         type->atomic.akind   = atomic_type;
4060                 }
4061                 type->base.alignment = get_atomic_type_alignment(atomic_type);
4062                 unsigned const size  = get_atomic_type_size(atomic_type);
4063                 type->base.size      =
4064                         type_specifiers & SPECIFIER_COMPLEX ? size * 2 : size;
4065                 newtype = true;
4066         } else if (type_specifiers != 0) {
4067                 errorf(HERE, "multiple datatypes in declaration");
4068         }
4069
4070         /* FIXME: check type qualifiers here */
4071
4072         if (specifiers->modifiers & DM_TRANSPARENT_UNION)
4073                 modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4074         type->base.qualifiers = qualifiers;
4075         type->base.modifiers  = modifiers;
4076
4077         if (newtype) {
4078                 type = identify_new_type(type);
4079         } else {
4080                 type = typehash_insert(type);
4081         }
4082
4083         type = handle_type_attributes(specifiers->gnu_attributes, type);
4084         specifiers->type = type;
4085         return;
4086
4087 end_error:
4088         specifiers->type = type_error_type;
4089         return;
4090 }
4091
4092 static type_qualifiers_t parse_type_qualifiers(void)
4093 {
4094         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
4095
4096         while (true) {
4097                 switch (token.type) {
4098                 /* type qualifiers */
4099                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
4100                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
4101                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
4102                 /* microsoft extended type modifiers */
4103                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
4104                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
4105                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
4106                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
4107                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
4108
4109                 default:
4110                         return qualifiers;
4111                 }
4112         }
4113 }
4114
4115 /**
4116  * Parses an K&R identifier list
4117  */
4118 static void parse_identifier_list(scope_t *scope)
4119 {
4120         do {
4121                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
4122                 entity->base.source_position = token.source_position;
4123                 entity->base.namespc         = NAMESPACE_NORMAL;
4124                 entity->base.symbol          = token.v.symbol;
4125                 /* a K&R parameter has no type, yet */
4126                 next_token();
4127
4128                 if (scope != NULL)
4129                         append_entity(scope, entity);
4130
4131                 if (token.type != ',') {
4132                         break;
4133                 }
4134                 next_token();
4135         } while (token.type == T_IDENTIFIER);
4136 }
4137
4138 static entity_t *parse_parameter(void)
4139 {
4140         declaration_specifiers_t specifiers;
4141         memset(&specifiers, 0, sizeof(specifiers));
4142
4143         parse_declaration_specifiers(&specifiers);
4144
4145         entity_t *entity = parse_declarator(&specifiers,
4146                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
4147         anonymous_entity = NULL;
4148         return entity;
4149 }
4150
4151 static void semantic_parameter_incomplete(const entity_t *entity)
4152 {
4153         assert(entity->kind == ENTITY_PARAMETER);
4154
4155         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
4156          *             list in a function declarator that is part of a
4157          *             definition of that function shall not have
4158          *             incomplete type. */
4159         type_t *type = skip_typeref(entity->declaration.type);
4160         if (is_type_incomplete(type)) {
4161                 errorf(&entity->base.source_position,
4162                        "parameter '%Y' has incomplete type '%T'", entity->base.symbol,
4163                        entity->declaration.type);
4164         }
4165 }
4166
4167 /**
4168  * Parses function type parameters (and optionally creates variable_t entities
4169  * for them in a scope)
4170  */
4171 static void parse_parameters(function_type_t *type, scope_t *scope)
4172 {
4173         eat('(');
4174         add_anchor_token(')');
4175         int saved_comma_state = save_and_reset_anchor_state(',');
4176
4177         if (token.type == T_IDENTIFIER &&
4178             !is_typedef_symbol(token.v.symbol)) {
4179                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
4180                 if (la1_type == ',' || la1_type == ')') {
4181                         type->kr_style_parameters    = true;
4182                         type->unspecified_parameters = true;
4183                         parse_identifier_list(scope);
4184                         goto parameters_finished;
4185                 }
4186         }
4187
4188         if (token.type == ')') {
4189                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
4190                 if (!(c_mode & _CXX))
4191                         type->unspecified_parameters = true;
4192                 goto parameters_finished;
4193         }
4194
4195         function_parameter_t *last_parameter = NULL;
4196
4197         while (true) {
4198                 switch (token.type) {
4199                 case T_DOTDOTDOT:
4200                         next_token();
4201                         type->variadic = true;
4202                         goto parameters_finished;
4203
4204                 case T_IDENTIFIER:
4205                 case T___extension__:
4206                 DECLARATION_START
4207                 {
4208                         entity_t *entity = parse_parameter();
4209                         if (entity->kind == ENTITY_TYPEDEF) {
4210                                 errorf(&entity->base.source_position,
4211                                        "typedef not allowed as function parameter");
4212                                 break;
4213                         }
4214                         assert(is_declaration(entity));
4215
4216                         /* func(void) is not a parameter */
4217                         if (last_parameter == NULL
4218                                         && token.type == ')'
4219                                         && entity->base.symbol == NULL
4220                                         && skip_typeref(entity->declaration.type) == type_void) {
4221                                 goto parameters_finished;
4222                         }
4223                         semantic_parameter_incomplete(entity);
4224
4225                         function_parameter_t *const parameter =
4226                                 allocate_parameter(entity->declaration.type);
4227
4228                         if (scope != NULL) {
4229                                 append_entity(scope, entity);
4230                         }
4231
4232                         if (last_parameter != NULL) {
4233                                 last_parameter->next = parameter;
4234                         } else {
4235                                 type->parameters = parameter;
4236                         }
4237                         last_parameter   = parameter;
4238                         break;
4239                 }
4240
4241                 default:
4242                         goto parameters_finished;
4243                 }
4244                 if (token.type != ',') {
4245                         goto parameters_finished;
4246                 }
4247                 next_token();
4248         }
4249
4250
4251 parameters_finished:
4252         rem_anchor_token(')');
4253         expect(')', end_error);
4254
4255 end_error:
4256         restore_anchor_state(',', saved_comma_state);
4257 }
4258
4259 typedef enum construct_type_kind_t {
4260         CONSTRUCT_INVALID,
4261         CONSTRUCT_POINTER,
4262         CONSTRUCT_REFERENCE,
4263         CONSTRUCT_FUNCTION,
4264         CONSTRUCT_ARRAY
4265 } construct_type_kind_t;
4266
4267 typedef union construct_type_t construct_type_t;
4268
4269 typedef struct construct_type_base_t {
4270         construct_type_kind_t  kind;
4271         construct_type_t      *next;
4272 } construct_type_base_t;
4273
4274 typedef struct parsed_pointer_t {
4275         construct_type_base_t  base;
4276         type_qualifiers_t      type_qualifiers;
4277         variable_t             *base_variable;  /**< MS __based extension. */
4278 } parsed_pointer_t;
4279
4280 typedef struct parsed_reference_t {
4281         construct_type_base_t base;
4282 } parsed_reference_t;
4283
4284 typedef struct construct_function_type_t {
4285         construct_type_base_t  base;
4286         type_t                *function_type;
4287 } construct_function_type_t;
4288
4289 typedef struct parsed_array_t {
4290         construct_type_base_t  base;
4291         type_qualifiers_t      type_qualifiers;
4292         bool                   is_static;
4293         bool                   is_variable;
4294         expression_t          *size;
4295 } parsed_array_t;
4296
4297 union construct_type_t {
4298         construct_type_kind_t     kind;
4299         construct_type_base_t     base;
4300         parsed_pointer_t          pointer;
4301         parsed_reference_t        reference;
4302         construct_function_type_t function;
4303         parsed_array_t            array;
4304 };
4305
4306 static construct_type_t *parse_pointer_declarator(variable_t *base_variable)
4307 {
4308         eat('*');
4309
4310         construct_type_t *cons    = obstack_alloc(&temp_obst, sizeof(cons->pointer));
4311         parsed_pointer_t *pointer = &cons->pointer;
4312         memset(pointer, 0, sizeof(*pointer));
4313         cons->kind               = CONSTRUCT_POINTER;
4314         pointer->type_qualifiers = parse_type_qualifiers();
4315         pointer->base_variable   = base_variable;
4316
4317         return cons;
4318 }
4319
4320 static construct_type_t *parse_reference_declarator(void)
4321 {
4322         eat('&');
4323
4324         construct_type_t   *cons      = obstack_alloc(&temp_obst, sizeof(cons->reference));
4325         parsed_reference_t *reference = &cons->reference;
4326         memset(reference, 0, sizeof(*reference));
4327         cons->kind = CONSTRUCT_REFERENCE;
4328
4329         return cons;
4330 }
4331
4332 static construct_type_t *parse_array_declarator(void)
4333 {
4334         eat('[');
4335         add_anchor_token(']');
4336
4337         construct_type_t *cons  = obstack_alloc(&temp_obst, sizeof(cons->array));
4338         parsed_array_t   *array = &cons->array;
4339         memset(array, 0, sizeof(*array));
4340         cons->kind = CONSTRUCT_ARRAY;
4341
4342         if (token.type == T_static) {
4343                 array->is_static = true;
4344                 next_token();
4345         }
4346
4347         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
4348         if (type_qualifiers != 0) {
4349                 if (token.type == T_static) {
4350                         array->is_static = true;
4351                         next_token();
4352                 }
4353         }
4354         array->type_qualifiers = type_qualifiers;
4355
4356         if (token.type == '*' && look_ahead(1)->type == ']') {
4357                 array->is_variable = true;
4358                 next_token();
4359         } else if (token.type != ']') {
4360                 expression_t *const size = parse_assignment_expression();
4361                 array->size = size;
4362                 mark_vars_read(size, NULL);
4363         }
4364
4365         rem_anchor_token(']');
4366         expect(']', end_error);
4367
4368 end_error:
4369         return cons;
4370 }
4371
4372 static construct_type_t *parse_function_declarator(scope_t *scope,
4373                                                    decl_modifiers_t modifiers)
4374 {
4375         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
4376         function_type_t *ftype = &type->function;
4377
4378         ftype->linkage = current_linkage;
4379
4380         switch (modifiers & (DM_CDECL | DM_STDCALL | DM_FASTCALL | DM_THISCALL)) {
4381                 case DM_NONE:     break;
4382                 case DM_CDECL:    ftype->calling_convention = CC_CDECL;    break;
4383                 case DM_STDCALL:  ftype->calling_convention = CC_STDCALL;  break;
4384                 case DM_FASTCALL: ftype->calling_convention = CC_FASTCALL; break;
4385                 case DM_THISCALL: ftype->calling_convention = CC_THISCALL; break;
4386
4387                 default:
4388                         errorf(HERE, "multiple calling conventions in declaration");
4389                         break;
4390         }
4391
4392         parse_parameters(ftype, scope);
4393
4394         construct_type_t          *cons     = obstack_alloc(&temp_obst, sizeof(cons->function));
4395         construct_function_type_t *function = &cons->function;
4396         memset(function, 0, sizeof(*function));
4397         cons->kind              = CONSTRUCT_FUNCTION;
4398         function->function_type = type;
4399
4400         return cons;
4401 }
4402
4403 typedef struct parse_declarator_env_t {
4404         decl_modifiers_t   modifiers;
4405         symbol_t          *symbol;
4406         source_position_t  source_position;
4407         scope_t            parameters;
4408 } parse_declarator_env_t;
4409
4410 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env,
4411                 bool may_be_abstract)
4412 {
4413         /* construct a single linked list of construct_type_t's which describe
4414          * how to construct the final declarator type */
4415         construct_type_t  *first      = NULL;
4416         construct_type_t **anchor     = &first;
4417         gnu_attribute_t   *attributes = NULL;
4418
4419         decl_modifiers_t modifiers = parse_attributes(&attributes);
4420
4421         for (;;) {
4422                 construct_type_t *type;
4423                 variable_t       *based = NULL; /* MS __based extension */
4424                 switch (token.type) {
4425                         case '&':
4426                                 if (!(c_mode & _CXX))
4427                                         errorf(HERE, "references are only available for C++");
4428                                 type = parse_reference_declarator();
4429                                 break;
4430
4431                         case T__based: {
4432                                 source_position_t const pos = *HERE;
4433                                 next_token();
4434                                 expect('(', end_error);
4435                                 add_anchor_token(')');
4436                                 based = parse_microsoft_based();
4437                                 rem_anchor_token(')');
4438                                 expect(')', end_error);
4439                                 if (token.type != '*') {
4440                                         if (token.type == T__based) {
4441                                                 errorf(&pos, "__based type modifier specified more than once");
4442                                         } else if (warning.other) {
4443                                                 warningf(&pos,
4444                                                                 "__based does not precede a pointer declarator, ignored");
4445                                         }
4446                                         continue;
4447                                 }
4448                                 /* FALLTHROUGH */
4449                         }
4450
4451                         case '*':
4452                                 type = parse_pointer_declarator(based);
4453                                 break;
4454
4455                         default:
4456                                 goto ptr_operator_end;
4457                 }
4458
4459                 *anchor = type;
4460                 anchor  = &type->base.next;
4461
4462                 /* TODO: find out if this is correct */
4463                 modifiers |= parse_attributes(&attributes);
4464         }
4465 ptr_operator_end:
4466
4467         if (env != NULL) {
4468                 modifiers      |= env->modifiers;
4469                 env->modifiers  = modifiers;
4470         }
4471
4472         construct_type_t *inner_types = NULL;
4473
4474         switch (token.type) {
4475         case T_IDENTIFIER:
4476                 if (env == NULL) {
4477                         errorf(HERE, "no identifier expected in typename");
4478                 } else {
4479                         env->symbol          = token.v.symbol;
4480                         env->source_position = token.source_position;
4481                 }
4482                 next_token();
4483                 break;
4484         case '(':
4485                 /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
4486                  * interpreted as ``function with no parameter specification'', rather
4487                  * than redundant parentheses around the omitted identifier. */
4488                 if (look_ahead(1)->type != ')') {
4489                         next_token();
4490                         add_anchor_token(')');
4491                         inner_types = parse_inner_declarator(env, may_be_abstract);
4492                         if (inner_types != NULL) {
4493                                 /* All later declarators only modify the return type */
4494                                 env = NULL;
4495                         }
4496                         rem_anchor_token(')');
4497                         expect(')', end_error);
4498                 }
4499                 break;
4500         default:
4501                 if (may_be_abstract)
4502                         break;
4503                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
4504                 eat_until_anchor();
4505                 return NULL;
4506         }
4507
4508         construct_type_t **const p = anchor;
4509
4510         for (;;) {
4511                 construct_type_t *type;
4512                 switch (token.type) {
4513                 case '(': {
4514                         scope_t *scope = NULL;
4515                         if (env != NULL)
4516                                 scope = &env->parameters;
4517
4518                         type = parse_function_declarator(scope, modifiers);
4519                         break;
4520                 }
4521                 case '[':
4522                         type = parse_array_declarator();
4523                         break;
4524                 default:
4525                         goto declarator_finished;
4526                 }
4527
4528                 /* insert in the middle of the list (at p) */
4529                 type->base.next = *p;
4530                 *p              = type;
4531                 if (anchor == p)
4532                         anchor = &type->base.next;
4533         }
4534
4535 declarator_finished:
4536         /* append inner_types at the end of the list, we don't to set anchor anymore
4537          * as it's not needed anymore */
4538         *anchor = inner_types;
4539
4540         return first;
4541 end_error:
4542         return NULL;
4543 }
4544
4545 static void parse_declaration_attributes(entity_t *entity)
4546 {
4547         gnu_attribute_t  *attributes = NULL;
4548         decl_modifiers_t  modifiers  = parse_attributes(&attributes);
4549
4550         if (entity == NULL)
4551                 return;
4552
4553         type_t *type;
4554         if (entity->kind == ENTITY_TYPEDEF) {
4555                 modifiers |= entity->typedefe.modifiers;
4556                 type       = entity->typedefe.type;
4557         } else {
4558                 assert(is_declaration(entity));
4559                 modifiers |= entity->declaration.modifiers;
4560                 type       = entity->declaration.type;
4561         }
4562         if (type == NULL)
4563                 return;
4564
4565         gnu_attribute_t *attribute = attributes;
4566         for ( ; attribute != NULL; attribute = attribute->next) {
4567                 if (attribute->invalid)
4568                         continue;
4569
4570                 if (attribute->kind == GNU_AK_MODE) {
4571                         type = handle_attribute_mode(attribute, type);
4572                 } else if (attribute->kind == GNU_AK_ALIGNED) {
4573                         int alignment = 32; /* TODO: fill in maximum usefull alignment for target machine */
4574                         if (attribute->has_arguments)
4575                                 alignment = attribute->u.argument;
4576
4577                         if (entity->kind == ENTITY_TYPEDEF) {
4578                                 type_t *copy         = duplicate_type(type);
4579                                 copy->base.alignment = attribute->u.argument;
4580                                 type                 = identify_new_type(copy);
4581                         } else if(entity->kind == ENTITY_VARIABLE) {
4582                                 entity->variable.alignment = alignment;
4583                         } else if(entity->kind == ENTITY_COMPOUND_MEMBER) {
4584                                 entity->compound_member.alignment = alignment;
4585                         }
4586                 }
4587         }
4588
4589         type_modifiers_t type_modifiers = type->base.modifiers;
4590         if (modifiers & DM_TRANSPARENT_UNION)
4591                 type_modifiers |= TYPE_MODIFIER_TRANSPARENT_UNION;
4592
4593         if (type->base.modifiers != type_modifiers) {
4594                 type_t *copy         = duplicate_type(type);
4595                 copy->base.modifiers = type_modifiers;
4596                 type                 = identify_new_type(copy);
4597         }
4598
4599         if (entity->kind == ENTITY_TYPEDEF) {
4600                 entity->typedefe.type      = type;
4601                 entity->typedefe.modifiers = modifiers;
4602         } else {
4603                 entity->declaration.type      = type;
4604                 entity->declaration.modifiers = modifiers;
4605         }
4606 }
4607
4608 static type_t *construct_declarator_type(construct_type_t *construct_list, type_t *type)
4609 {
4610         construct_type_t *iter = construct_list;
4611         for (; iter != NULL; iter = iter->base.next) {
4612                 switch (iter->kind) {
4613                 case CONSTRUCT_INVALID:
4614                         break;
4615                 case CONSTRUCT_FUNCTION: {
4616                         construct_function_type_t *function      = &iter->function;
4617                         type_t                    *function_type = function->function_type;
4618
4619                         function_type->function.return_type = type;
4620
4621                         type_t *skipped_return_type = skip_typeref(type);
4622                         /* §6.7.5.3:1 */
4623                         if (is_type_function(skipped_return_type)) {
4624                                 errorf(HERE, "function returning function is not allowed");
4625                         } else if (is_type_array(skipped_return_type)) {
4626                                 errorf(HERE, "function returning array is not allowed");
4627                         } else {
4628                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
4629                                         warningf(HERE,
4630                                                 "type qualifiers in return type of function type are meaningless");
4631                                 }
4632                         }
4633
4634                         /* The function type was constructed earlier.  Freeing it here will
4635                          * destroy other types. */
4636                         type = typehash_insert(function_type);
4637                         continue;
4638                 }
4639
4640                 case CONSTRUCT_POINTER: {
4641                         if (is_type_reference(skip_typeref(type)))
4642                                 errorf(HERE, "cannot declare a pointer to reference");
4643
4644                         parsed_pointer_t *pointer = &iter->pointer;
4645                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
4646                         continue;
4647                 }
4648
4649                 case CONSTRUCT_REFERENCE:
4650                         if (is_type_reference(skip_typeref(type)))
4651                                 errorf(HERE, "cannot declare a reference to reference");
4652
4653                         type = make_reference_type(type);
4654                         continue;
4655
4656                 case CONSTRUCT_ARRAY: {
4657                         if (is_type_reference(skip_typeref(type)))
4658                                 errorf(HERE, "cannot declare an array of references");
4659
4660                         parsed_array_t *array      = &iter->array;
4661                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
4662
4663                         expression_t *size_expression = array->size;
4664                         if (size_expression != NULL) {
4665                                 size_expression
4666                                         = create_implicit_cast(size_expression, type_size_t);
4667                         }
4668
4669                         array_type->base.qualifiers       = array->type_qualifiers;
4670                         array_type->array.element_type    = type;
4671                         array_type->array.is_static       = array->is_static;
4672                         array_type->array.is_variable     = array->is_variable;
4673                         array_type->array.size_expression = size_expression;
4674
4675                         if (size_expression != NULL) {
4676                                 if (is_constant_expression(size_expression)) {
4677                                         array_type->array.size_constant = true;
4678                                         array_type->array.size
4679                                                 = fold_constant(size_expression);
4680                                 } else {
4681                                         array_type->array.is_vla = true;
4682                                 }
4683                         }
4684
4685                         type_t *skipped_type = skip_typeref(type);
4686                         /* §6.7.5.2:1 */
4687                         if (is_type_incomplete(skipped_type)) {
4688                                 errorf(HERE, "array of incomplete type '%T' is not allowed", type);
4689                         } else if (is_type_function(skipped_type)) {
4690                                 errorf(HERE, "array of functions is not allowed");
4691                         }
4692                         type = identify_new_type(array_type);
4693                         continue;
4694                 }
4695                 }
4696                 internal_errorf(HERE, "invalid type construction found");
4697         }
4698
4699         return type;
4700 }
4701
4702 static type_t *automatic_type_conversion(type_t *orig_type);
4703
4704 static type_t *semantic_parameter(const source_position_t *pos,
4705                                   type_t *type,
4706                                   const declaration_specifiers_t *specifiers,
4707                                   symbol_t *symbol)
4708 {
4709         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
4710          *             shall be adjusted to ``qualified pointer to type'',
4711          *             [...]
4712          * §6.7.5.3:8  A declaration of a parameter as ``function returning
4713          *             type'' shall be adjusted to ``pointer to function
4714          *             returning type'', as in 6.3.2.1. */
4715         type = automatic_type_conversion(type);
4716
4717         if (specifiers->is_inline && is_type_valid(type)) {
4718                 errorf(pos, "parameter '%Y' declared 'inline'", symbol);
4719         }
4720
4721         /* §6.9.1:6  The declarations in the declaration list shall contain
4722          *           no storage-class specifier other than register and no
4723          *           initializations. */
4724         if (specifiers->thread_local || (
4725                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4726                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
4727            ) {
4728                 errorf(pos, "invalid storage class for parameter '%Y'", symbol);
4729         }
4730
4731         /* delay test for incomplete type, because we might have (void)
4732          * which is legal but incomplete... */
4733
4734         return type;
4735 }
4736
4737 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
4738                                   declarator_flags_t flags)
4739 {
4740         parse_declarator_env_t env;
4741         memset(&env, 0, sizeof(env));
4742         env.modifiers = specifiers->modifiers;
4743
4744         construct_type_t *construct_type =
4745                 parse_inner_declarator(&env, (flags & DECL_MAY_BE_ABSTRACT) != 0);
4746         type_t           *orig_type      =
4747                 construct_declarator_type(construct_type, specifiers->type);
4748         type_t           *type           = skip_typeref(orig_type);
4749
4750         if (construct_type != NULL) {
4751                 obstack_free(&temp_obst, construct_type);
4752         }
4753
4754         entity_t *entity;
4755         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
4756                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
4757                 entity->base.symbol          = env.symbol;
4758                 entity->base.source_position = env.source_position;
4759                 entity->typedefe.type        = orig_type;
4760
4761                 if (anonymous_entity != NULL) {
4762                         if (is_type_compound(type)) {
4763                                 assert(anonymous_entity->compound.alias == NULL);
4764                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
4765                                        anonymous_entity->kind == ENTITY_UNION);
4766                                 anonymous_entity->compound.alias = entity;
4767                                 anonymous_entity = NULL;
4768                         } else if (is_type_enum(type)) {
4769                                 assert(anonymous_entity->enume.alias == NULL);
4770                                 assert(anonymous_entity->kind == ENTITY_ENUM);
4771                                 anonymous_entity->enume.alias = entity;
4772                                 anonymous_entity = NULL;
4773                         }
4774                 }
4775         } else {
4776                 /* create a declaration type entity */
4777                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
4778                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
4779
4780                         if (env.symbol != NULL) {
4781                                 if (specifiers->is_inline && is_type_valid(type)) {
4782                                         errorf(&env.source_position,
4783                                                         "compound member '%Y' declared 'inline'", env.symbol);
4784                                 }
4785
4786                                 if (specifiers->thread_local ||
4787                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
4788                                         errorf(&env.source_position,
4789                                                         "compound member '%Y' must have no storage class",
4790                                                         env.symbol);
4791                                 }
4792                         }
4793                 } else if (flags & DECL_IS_PARAMETER) {
4794                         orig_type = semantic_parameter(&env.source_position, orig_type,
4795                                                        specifiers, env.symbol);
4796
4797                         entity = allocate_entity_zero(ENTITY_PARAMETER);
4798                 } else if (is_type_function(type)) {
4799                         entity = allocate_entity_zero(ENTITY_FUNCTION);
4800
4801                         entity->function.is_inline  = specifiers->is_inline;
4802                         entity->function.parameters = env.parameters;
4803
4804                         if (env.symbol != NULL) {
4805                                 if (specifiers->thread_local || (
4806                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4807                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4808                                                         specifiers->storage_class != STORAGE_CLASS_STATIC
4809                                                 )) {
4810                                         errorf(&env.source_position,
4811                                                         "invalid storage class for function '%Y'", env.symbol);
4812                                 }
4813                         }
4814                 } else {
4815                         entity = allocate_entity_zero(ENTITY_VARIABLE);
4816
4817                         entity->variable.get_property_sym = specifiers->get_property_sym;
4818                         entity->variable.put_property_sym = specifiers->put_property_sym;
4819
4820                         entity->variable.thread_local = specifiers->thread_local;
4821
4822                         if (env.symbol != NULL) {
4823                                 if (specifiers->is_inline && is_type_valid(type)) {
4824                                         errorf(&env.source_position,
4825                                                         "variable '%Y' declared 'inline'", env.symbol);
4826                                 }
4827
4828                                 bool invalid_storage_class = false;
4829                                 if (current_scope == file_scope) {
4830                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
4831                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
4832                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
4833                                                 invalid_storage_class = true;
4834                                         }
4835                                 } else {
4836                                         if (specifiers->thread_local &&
4837                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
4838                                                 invalid_storage_class = true;
4839                                         }
4840                                 }
4841                                 if (invalid_storage_class) {
4842                                         errorf(&env.source_position,
4843                                                         "invalid storage class for variable '%Y'", env.symbol);
4844                                 }
4845                         }
4846                 }
4847
4848                 if (env.symbol != NULL) {
4849                         entity->base.symbol          = env.symbol;
4850                         entity->base.source_position = env.source_position;
4851                 } else {
4852                         entity->base.source_position = specifiers->source_position;
4853                 }
4854                 entity->base.namespc                  = NAMESPACE_NORMAL;
4855                 entity->declaration.type              = orig_type;
4856                 entity->declaration.modifiers         = env.modifiers;
4857                 entity->declaration.deprecated_string = specifiers->deprecated_string;
4858
4859                 storage_class_t storage_class = specifiers->storage_class;
4860                 entity->declaration.declared_storage_class = storage_class;
4861
4862                 if (storage_class == STORAGE_CLASS_NONE && current_scope != file_scope)
4863                         storage_class = STORAGE_CLASS_AUTO;
4864                 entity->declaration.storage_class = storage_class;
4865         }
4866
4867         parse_declaration_attributes(entity);
4868
4869         return entity;
4870 }
4871
4872 static type_t *parse_abstract_declarator(type_t *base_type)
4873 {
4874         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
4875
4876         type_t *result = construct_declarator_type(construct_type, base_type);
4877         if (construct_type != NULL) {
4878                 obstack_free(&temp_obst, construct_type);
4879         }
4880
4881         return result;
4882 }
4883
4884 /**
4885  * Check if the declaration of main is suspicious.  main should be a
4886  * function with external linkage, returning int, taking either zero
4887  * arguments, two, or three arguments of appropriate types, ie.
4888  *
4889  * int main([ int argc, char **argv [, char **env ] ]).
4890  *
4891  * @param decl    the declaration to check
4892  * @param type    the function type of the declaration
4893  */
4894 static void check_type_of_main(const entity_t *entity)
4895 {
4896         const source_position_t *pos = &entity->base.source_position;
4897         if (entity->kind != ENTITY_FUNCTION) {
4898                 warningf(pos, "'main' is not a function");
4899                 return;
4900         }
4901
4902         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4903                 warningf(pos, "'main' is normally a non-static function");
4904         }
4905
4906         type_t *type = skip_typeref(entity->declaration.type);
4907         assert(is_type_function(type));
4908
4909         function_type_t *func_type = &type->function;
4910         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4911                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4912                          func_type->return_type);
4913         }
4914         const function_parameter_t *parm = func_type->parameters;
4915         if (parm != NULL) {
4916                 type_t *const first_type = parm->type;
4917                 if (!types_compatible(skip_typeref(first_type), type_int)) {
4918                         warningf(pos,
4919                                  "first argument of 'main' should be 'int', but is '%T'",
4920                                  first_type);
4921                 }
4922                 parm = parm->next;
4923                 if (parm != NULL) {
4924                         type_t *const second_type = parm->type;
4925                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
4926                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'", second_type);
4927                         }
4928                         parm = parm->next;
4929                         if (parm != NULL) {
4930                                 type_t *const third_type = parm->type;
4931                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
4932                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'", third_type);
4933                                 }
4934                                 parm = parm->next;
4935                                 if (parm != NULL)
4936                                         goto warn_arg_count;
4937                         }
4938                 } else {
4939 warn_arg_count:
4940                         warningf(pos, "'main' takes only zero, two or three arguments");
4941                 }
4942         }
4943 }
4944
4945 /**
4946  * Check if a symbol is the equal to "main".
4947  */
4948 static bool is_sym_main(const symbol_t *const sym)
4949 {
4950         return strcmp(sym->string, "main") == 0;
4951 }
4952
4953 static void error_redefined_as_different_kind(const source_position_t *pos,
4954                 const entity_t *old, entity_kind_t new_kind)
4955 {
4956         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4957                get_entity_kind_name(old->kind), old->base.symbol,
4958                get_entity_kind_name(new_kind), &old->base.source_position);
4959 }
4960
4961 static bool is_error_entity(entity_t *const ent)
4962 {
4963         if (is_declaration(ent)) {
4964                 return is_type_valid(skip_typeref(ent->declaration.type));
4965         } else if (ent->kind == ENTITY_TYPEDEF) {
4966                 return is_type_valid(skip_typeref(ent->typedefe.type));
4967         }
4968         return false;
4969 }
4970
4971 /**
4972  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4973  * for various problems that occur for multiple definitions
4974  */
4975 static entity_t *record_entity(entity_t *entity, const bool is_definition)
4976 {
4977         const symbol_t *const    symbol  = entity->base.symbol;
4978         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4979         const source_position_t *pos     = &entity->base.source_position;
4980
4981         /* can happen in error cases */
4982         if (symbol == NULL)
4983                 return entity;
4984
4985         entity_t *const previous_entity = get_entity(symbol, namespc);
4986         /* pushing the same entity twice will break the stack structure */
4987         assert(previous_entity != entity);
4988
4989         if (entity->kind == ENTITY_FUNCTION) {
4990                 type_t *const orig_type = entity->declaration.type;
4991                 type_t *const type      = skip_typeref(orig_type);
4992
4993                 assert(is_type_function(type));
4994                 if (type->function.unspecified_parameters &&
4995                                 warning.strict_prototypes &&
4996                                 previous_entity == NULL) {
4997                         warningf(pos, "function declaration '%#T' is not a prototype",
4998                                          orig_type, symbol);
4999                 }
5000
5001                 if (warning.main && current_scope == file_scope
5002                                 && is_sym_main(symbol)) {
5003                         check_type_of_main(entity);
5004                 }
5005         }
5006
5007         if (is_declaration(entity) &&
5008                         warning.nested_externs &&
5009                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
5010                         current_scope != file_scope) {
5011                 warningf(pos, "nested extern declaration of '%#T'",
5012                          entity->declaration.type, symbol);
5013         }
5014
5015         if (previous_entity != NULL) {
5016                 if (previous_entity->base.parent_scope == &current_function->parameters &&
5017                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
5018                         assert(previous_entity->kind == ENTITY_PARAMETER);
5019                         errorf(pos,
5020                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
5021                                         entity->declaration.type, symbol,
5022                                         previous_entity->declaration.type, symbol,
5023                                         &previous_entity->base.source_position);
5024                         goto finish;
5025                 }
5026
5027                 if (previous_entity->base.parent_scope == current_scope) {
5028                         if (previous_entity->kind != entity->kind) {
5029                                 if (!is_error_entity(previous_entity) && !is_error_entity(entity)) {
5030                                         error_redefined_as_different_kind(pos, previous_entity,
5031                                                         entity->kind);
5032                                 }
5033                                 goto finish;
5034                         }
5035                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
5036                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
5037                                                 symbol, &previous_entity->base.source_position);
5038                                 goto finish;
5039                         }
5040                         if (previous_entity->kind == ENTITY_TYPEDEF) {
5041                                 /* TODO: C++ allows this for exactly the same type */
5042                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
5043                                                 symbol, &previous_entity->base.source_position);
5044                                 goto finish;
5045                         }
5046
5047                         /* at this point we should have only VARIABLES or FUNCTIONS */
5048                         assert(is_declaration(previous_entity) && is_declaration(entity));
5049
5050                         declaration_t *const prev_decl = &previous_entity->declaration;
5051                         declaration_t *const decl      = &entity->declaration;
5052
5053                         /* can happen for K&R style declarations */
5054                         if (prev_decl->type       == NULL             &&
5055                                         previous_entity->kind == ENTITY_PARAMETER &&
5056                                         entity->kind          == ENTITY_PARAMETER) {
5057                                 prev_decl->type                   = decl->type;
5058                                 prev_decl->storage_class          = decl->storage_class;
5059                                 prev_decl->declared_storage_class = decl->declared_storage_class;
5060                                 prev_decl->modifiers              = decl->modifiers;
5061                                 prev_decl->deprecated_string      = decl->deprecated_string;
5062                                 return previous_entity;
5063                         }
5064
5065                         type_t *const orig_type = decl->type;
5066                         assert(orig_type != NULL);
5067                         type_t *const type      = skip_typeref(orig_type);
5068                         type_t *const prev_type = skip_typeref(prev_decl->type);
5069
5070                         if (!types_compatible(type, prev_type)) {
5071                                 errorf(pos,
5072                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
5073                                                 orig_type, symbol, prev_decl->type, symbol,
5074                                                 &previous_entity->base.source_position);
5075                         } else {
5076                                 unsigned old_storage_class = prev_decl->storage_class;
5077                                 if (warning.redundant_decls               &&
5078                                                 is_definition                     &&
5079                                                 !prev_decl->used                  &&
5080                                                 !(prev_decl->modifiers & DM_USED) &&
5081                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
5082                                         warningf(&previous_entity->base.source_position,
5083                                                         "unnecessary static forward declaration for '%#T'",
5084                                                         prev_decl->type, symbol);
5085                                 }
5086
5087                                 storage_class_t new_storage_class = decl->storage_class;
5088
5089                                 /* pretend no storage class means extern for function
5090                                  * declarations (except if the previous declaration is neither
5091                                  * none nor extern) */
5092                                 if (entity->kind == ENTITY_FUNCTION) {
5093                                         /* the previous declaration could have unspecified parameters or
5094                                          * be a typedef, so use the new type */
5095                                         if (prev_type->function.unspecified_parameters || is_definition)
5096                                                 prev_decl->type = type;
5097
5098                                         switch (old_storage_class) {
5099                                                 case STORAGE_CLASS_NONE:
5100                                                         old_storage_class = STORAGE_CLASS_EXTERN;
5101                                                         /* FALLTHROUGH */
5102
5103                                                 case STORAGE_CLASS_EXTERN:
5104                                                         if (is_definition) {
5105                                                                 if (warning.missing_prototypes &&
5106                                                                                 prev_type->function.unspecified_parameters &&
5107                                                                                 !is_sym_main(symbol)) {
5108                                                                         warningf(pos, "no previous prototype for '%#T'",
5109                                                                                         orig_type, symbol);
5110                                                                 }
5111                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
5112                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
5113                                                         }
5114                                                         break;
5115
5116                                                 default:
5117                                                         break;
5118                                         }
5119                                 } else if (is_type_incomplete(prev_type)) {
5120                                         prev_decl->type = type;
5121                                 }
5122
5123                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
5124                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
5125 warn_redundant_declaration:
5126                                         if (!is_definition           &&
5127                                                         warning.redundant_decls  &&
5128                                                         is_type_valid(prev_type) &&
5129                                                         strcmp(previous_entity->base.source_position.input_name,
5130                                                                 "<builtin>") != 0) {
5131                                                 warningf(pos,
5132                                                                 "redundant declaration for '%Y' (declared %P)",
5133                                                                 symbol, &previous_entity->base.source_position);
5134                                         }
5135                                 } else if (current_function == NULL) {
5136                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
5137                                                         new_storage_class == STORAGE_CLASS_STATIC) {
5138                                                 errorf(pos,
5139                                                                 "static declaration of '%Y' follows non-static declaration (declared %P)",
5140                                                                 symbol, &previous_entity->base.source_position);
5141                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
5142                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
5143                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
5144                                         } else {
5145                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
5146                                                 if (c_mode & _CXX)
5147                                                         goto error_redeclaration;
5148                                                 goto warn_redundant_declaration;
5149                                         }
5150                                 } else if (is_type_valid(prev_type)) {
5151                                         if (old_storage_class == new_storage_class) {
5152 error_redeclaration:
5153                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
5154                                                                 symbol, &previous_entity->base.source_position);
5155                                         } else {
5156                                                 errorf(pos,
5157                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
5158                                                                 symbol, &previous_entity->base.source_position);
5159                                         }
5160                                 }
5161                         }
5162
5163                         prev_decl->modifiers |= decl->modifiers;
5164                         if (entity->kind == ENTITY_FUNCTION) {
5165                                 previous_entity->function.is_inline |= entity->function.is_inline;
5166                         }
5167                         return previous_entity;
5168                 }
5169
5170                 if (warning.shadow) {
5171                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
5172                                         get_entity_kind_name(entity->kind), symbol,
5173                                         get_entity_kind_name(previous_entity->kind),
5174                                         &previous_entity->base.source_position);
5175                 }
5176         }
5177
5178         if (entity->kind == ENTITY_FUNCTION) {
5179                 if (is_definition &&
5180                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
5181                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
5182                                 warningf(pos, "no previous prototype for '%#T'",
5183                                          entity->declaration.type, symbol);
5184                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
5185                                 warningf(pos, "no previous declaration for '%#T'",
5186                                          entity->declaration.type, symbol);
5187                         }
5188                 }
5189         } else if (warning.missing_declarations &&
5190                         entity->kind == ENTITY_VARIABLE &&
5191                         current_scope == file_scope) {
5192                 declaration_t *declaration = &entity->declaration;
5193                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
5194                         warningf(pos, "no previous declaration for '%#T'",
5195                                  declaration->type, symbol);
5196                 }
5197         }
5198
5199 finish:
5200         assert(entity->base.parent_scope == NULL);
5201         assert(current_scope != NULL);
5202
5203         entity->base.parent_scope = current_scope;
5204         entity->base.namespc      = NAMESPACE_NORMAL;
5205         environment_push(entity);
5206         append_entity(current_scope, entity);
5207
5208         return entity;
5209 }
5210
5211 static void parser_error_multiple_definition(entity_t *entity,
5212                 const source_position_t *source_position)
5213 {
5214         errorf(source_position, "multiple definition of '%Y' (declared %P)",
5215                entity->base.symbol, &entity->base.source_position);
5216 }
5217
5218 static bool is_declaration_specifier(const token_t *token,
5219                                      bool only_specifiers_qualifiers)
5220 {
5221         switch (token->type) {
5222                 TYPE_SPECIFIERS
5223                 TYPE_QUALIFIERS
5224                         return true;
5225                 case T_IDENTIFIER:
5226                         return is_typedef_symbol(token->v.symbol);
5227
5228                 case T___extension__:
5229                 STORAGE_CLASSES
5230                         return !only_specifiers_qualifiers;
5231
5232                 default:
5233                         return false;
5234         }
5235 }
5236
5237 static void parse_init_declarator_rest(entity_t *entity)
5238 {
5239         assert(is_declaration(entity));
5240         declaration_t *const declaration = &entity->declaration;
5241
5242         eat('=');
5243
5244         type_t *orig_type = declaration->type;
5245         type_t *type      = skip_typeref(orig_type);
5246
5247         if (entity->kind == ENTITY_VARIABLE
5248                         && entity->variable.initializer != NULL) {
5249                 parser_error_multiple_definition(entity, HERE);
5250         }
5251
5252         bool must_be_constant = false;
5253         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
5254             entity->base.parent_scope  == file_scope) {
5255                 must_be_constant = true;
5256         }
5257
5258         if (is_type_function(type)) {
5259                 errorf(&entity->base.source_position,
5260                        "function '%#T' is initialized like a variable",
5261                        orig_type, entity->base.symbol);
5262                 orig_type = type_error_type;
5263         }
5264
5265         parse_initializer_env_t env;
5266         env.type             = orig_type;
5267         env.must_be_constant = must_be_constant;
5268         env.entity           = entity;
5269         current_init_decl    = entity;
5270
5271         initializer_t *initializer = parse_initializer(&env);
5272         current_init_decl = NULL;
5273
5274         if (entity->kind == ENTITY_VARIABLE) {
5275                 /* §6.7.5:22  array initializers for arrays with unknown size
5276                  * determine the array type size */
5277                 declaration->type            = env.type;
5278                 entity->variable.initializer = initializer;
5279         }
5280 }
5281
5282 /* parse rest of a declaration without any declarator */
5283 static void parse_anonymous_declaration_rest(
5284                 const declaration_specifiers_t *specifiers)
5285 {
5286         eat(';');
5287         anonymous_entity = NULL;
5288
5289         if (warning.other) {
5290                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
5291                                 specifiers->thread_local) {
5292                         warningf(&specifiers->source_position,
5293                                  "useless storage class in empty declaration");
5294                 }
5295
5296                 type_t *type = specifiers->type;
5297                 switch (type->kind) {
5298                         case TYPE_COMPOUND_STRUCT:
5299                         case TYPE_COMPOUND_UNION: {
5300                                 if (type->compound.compound->base.symbol == NULL) {
5301                                         warningf(&specifiers->source_position,
5302                                                  "unnamed struct/union that defines no instances");
5303                                 }
5304                                 break;
5305                         }
5306
5307                         case TYPE_ENUM:
5308                                 break;
5309
5310                         default:
5311                                 warningf(&specifiers->source_position, "empty declaration");
5312                                 break;
5313                 }
5314         }
5315 }
5316
5317 static void check_variable_type_complete(entity_t *ent)
5318 {
5319         if (ent->kind != ENTITY_VARIABLE)
5320                 return;
5321
5322         /* §6.7:7  If an identifier for an object is declared with no linkage, the
5323          *         type for the object shall be complete [...] */
5324         declaration_t *decl = &ent->declaration;
5325         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
5326                         decl->storage_class == STORAGE_CLASS_STATIC)
5327                 return;
5328
5329         type_t *const orig_type = decl->type;
5330         type_t *const type      = skip_typeref(orig_type);
5331         if (!is_type_incomplete(type))
5332                 return;
5333
5334         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
5335          * are given length one. */
5336         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
5337                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
5338                 return;
5339         }
5340
5341         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
5342                         orig_type, ent->base.symbol);
5343 }
5344
5345
5346 static void parse_declaration_rest(entity_t *ndeclaration,
5347                 const declaration_specifiers_t *specifiers,
5348                 parsed_declaration_func         finished_declaration,
5349                 declarator_flags_t              flags)
5350 {
5351         add_anchor_token(';');
5352         add_anchor_token(',');
5353         while (true) {
5354                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
5355
5356                 if (token.type == '=') {
5357                         parse_init_declarator_rest(entity);
5358                 } else if (entity->kind == ENTITY_VARIABLE) {
5359                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
5360                          * [...] where the extern specifier is explicitly used. */
5361                         declaration_t *decl = &entity->declaration;
5362                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
5363                                 type_t *type = decl->type;
5364                                 if (is_type_reference(skip_typeref(type))) {
5365                                         errorf(&entity->base.source_position,
5366                                                         "reference '%#T' must be initialized",
5367                                                         type, entity->base.symbol);
5368                                 }
5369                         }
5370                 }
5371
5372                 check_variable_type_complete(entity);
5373
5374                 if (token.type != ',')
5375                         break;
5376                 eat(',');
5377
5378                 add_anchor_token('=');
5379                 ndeclaration = parse_declarator(specifiers, flags);
5380                 rem_anchor_token('=');
5381         }
5382         expect(';', end_error);
5383
5384 end_error:
5385         anonymous_entity = NULL;
5386         rem_anchor_token(';');
5387         rem_anchor_token(',');
5388 }
5389
5390 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
5391 {
5392         symbol_t *symbol = entity->base.symbol;
5393         if (symbol == NULL) {
5394                 errorf(HERE, "anonymous declaration not valid as function parameter");
5395                 return entity;
5396         }
5397
5398         assert(entity->base.namespc == NAMESPACE_NORMAL);
5399         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
5400         if (previous_entity == NULL
5401                         || previous_entity->base.parent_scope != current_scope) {
5402                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
5403                        symbol);
5404                 return entity;
5405         }
5406
5407         if (is_definition) {
5408                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
5409         }
5410
5411         return record_entity(entity, false);
5412 }
5413
5414 static void parse_declaration(parsed_declaration_func finished_declaration,
5415                               declarator_flags_t      flags)
5416 {
5417         declaration_specifiers_t specifiers;
5418         memset(&specifiers, 0, sizeof(specifiers));
5419
5420         add_anchor_token(';');
5421         parse_declaration_specifiers(&specifiers);
5422         rem_anchor_token(';');
5423
5424         if (token.type == ';') {
5425                 parse_anonymous_declaration_rest(&specifiers);
5426         } else {
5427                 entity_t *entity = parse_declarator(&specifiers, flags);
5428                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
5429         }
5430 }
5431
5432 static type_t *get_default_promoted_type(type_t *orig_type)
5433 {
5434         type_t *result = orig_type;
5435
5436         type_t *type = skip_typeref(orig_type);
5437         if (is_type_integer(type)) {
5438                 result = promote_integer(type);
5439         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
5440                 result = type_double;
5441         }
5442
5443         return result;
5444 }
5445
5446 static void parse_kr_declaration_list(entity_t *entity)
5447 {
5448         if (entity->kind != ENTITY_FUNCTION)
5449                 return;
5450
5451         type_t *type = skip_typeref(entity->declaration.type);
5452         assert(is_type_function(type));
5453         if (!type->function.kr_style_parameters)
5454                 return;
5455
5456
5457         add_anchor_token('{');
5458
5459         /* push function parameters */
5460         size_t const  top       = environment_top();
5461         scope_t      *old_scope = scope_push(&entity->function.parameters);
5462
5463         entity_t *parameter = entity->function.parameters.entities;
5464         for ( ; parameter != NULL; parameter = parameter->base.next) {
5465                 assert(parameter->base.parent_scope == NULL);
5466                 parameter->base.parent_scope = current_scope;
5467                 environment_push(parameter);
5468         }
5469
5470         /* parse declaration list */
5471         for (;;) {
5472                 switch (token.type) {
5473                         DECLARATION_START
5474                         case T___extension__:
5475                         /* This covers symbols, which are no type, too, and results in
5476                          * better error messages.  The typical cases are misspelled type
5477                          * names and missing includes. */
5478                         case T_IDENTIFIER:
5479                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
5480                                 break;
5481                         default:
5482                                 goto decl_list_end;
5483                 }
5484         }
5485 decl_list_end:
5486
5487         /* pop function parameters */
5488         assert(current_scope == &entity->function.parameters);
5489         scope_pop(old_scope);
5490         environment_pop_to(top);
5491
5492         /* update function type */
5493         type_t *new_type = duplicate_type(type);
5494
5495         function_parameter_t *parameters     = NULL;
5496         function_parameter_t *last_parameter = NULL;
5497
5498         parameter = entity->function.parameters.entities;
5499         for (; parameter != NULL; parameter = parameter->base.next) {
5500                 if (parameter->kind != ENTITY_PARAMETER)
5501                         continue;
5502
5503                 type_t *parameter_type = parameter->declaration.type;
5504                 if (parameter_type == NULL) {
5505                         if (strict_mode) {
5506                                 errorf(HERE, "no type specified for function parameter '%Y'",
5507                                        parameter->base.symbol);
5508                         } else {
5509                                 if (warning.implicit_int) {
5510                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
5511                                                  parameter->base.symbol);
5512                                 }
5513                                 parameter_type              = type_int;
5514                                 parameter->declaration.type = parameter_type;
5515                         }
5516                 }
5517
5518                 semantic_parameter_incomplete(parameter);
5519                 parameter_type = parameter->declaration.type;
5520
5521                 /*
5522                  * we need the default promoted types for the function type
5523                  */
5524                 parameter_type = get_default_promoted_type(parameter_type);
5525
5526                 function_parameter_t *const parameter =
5527                         allocate_parameter(parameter_type);
5528
5529                 if (last_parameter != NULL) {
5530                         last_parameter->next = parameter;
5531                 } else {
5532                         parameters = parameter;
5533                 }
5534                 last_parameter = parameter;
5535         }
5536
5537         /* §6.9.1.7: A K&R style parameter list does NOT act as a function
5538          * prototype */
5539         new_type->function.parameters             = parameters;
5540         new_type->function.unspecified_parameters = true;
5541
5542         new_type = identify_new_type(new_type);
5543
5544         entity->declaration.type = new_type;
5545
5546         rem_anchor_token('{');
5547 }
5548
5549 static bool first_err = true;
5550
5551 /**
5552  * When called with first_err set, prints the name of the current function,
5553  * else does noting.
5554  */
5555 static void print_in_function(void)
5556 {
5557         if (first_err) {
5558                 first_err = false;
5559                 diagnosticf("%s: In function '%Y':\n",
5560                             current_function->base.base.source_position.input_name,
5561                             current_function->base.base.symbol);
5562         }
5563 }
5564
5565 /**
5566  * Check if all labels are defined in the current function.
5567  * Check if all labels are used in the current function.
5568  */
5569 static void check_labels(void)
5570 {
5571         for (const goto_statement_t *goto_statement = goto_first;
5572             goto_statement != NULL;
5573             goto_statement = goto_statement->next) {
5574                 /* skip computed gotos */
5575                 if (goto_statement->expression != NULL)
5576                         continue;
5577
5578                 label_t *label = goto_statement->label;
5579
5580                 label->used = true;
5581                 if (label->base.source_position.input_name == NULL) {
5582                         print_in_function();
5583                         errorf(&goto_statement->base.source_position,
5584                                "label '%Y' used but not defined", label->base.symbol);
5585                  }
5586         }
5587
5588         if (warning.unused_label) {
5589                 for (const label_statement_t *label_statement = label_first;
5590                          label_statement != NULL;
5591                          label_statement = label_statement->next) {
5592                         label_t *label = label_statement->label;
5593
5594                         if (! label->used) {
5595                                 print_in_function();
5596                                 warningf(&label_statement->base.source_position,
5597                                          "label '%Y' defined but not used", label->base.symbol);
5598                         }
5599                 }
5600         }
5601 }
5602
5603 static void warn_unused_entity(entity_t *entity, entity_t *last)
5604 {
5605         entity_t const *const end = last != NULL ? last->base.next : NULL;
5606         for (; entity != end; entity = entity->base.next) {
5607                 if (!is_declaration(entity))
5608                         continue;
5609
5610                 declaration_t *declaration = &entity->declaration;
5611                 if (declaration->implicit)
5612                         continue;
5613
5614                 if (!declaration->used) {
5615                         print_in_function();
5616                         const char *what = get_entity_kind_name(entity->kind);
5617                         warningf(&entity->base.source_position, "%s '%Y' is unused",
5618                                  what, entity->base.symbol);
5619                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
5620                         print_in_function();
5621                         const char *what = get_entity_kind_name(entity->kind);
5622                         warningf(&entity->base.source_position, "%s '%Y' is never read",
5623                                  what, entity->base.symbol);
5624                 }
5625         }
5626 }
5627
5628 static void check_unused_variables(statement_t *const stmt, void *const env)
5629 {
5630         (void)env;
5631
5632         switch (stmt->kind) {
5633                 case STATEMENT_DECLARATION: {
5634                         declaration_statement_t const *const decls = &stmt->declaration;
5635                         warn_unused_entity(decls->declarations_begin,
5636                                            decls->declarations_end);
5637                         return;
5638                 }
5639
5640                 case STATEMENT_FOR:
5641                         warn_unused_entity(stmt->fors.scope.entities, NULL);
5642                         return;
5643
5644                 default:
5645                         return;
5646         }
5647 }
5648
5649 /**
5650  * Check declarations of current_function for unused entities.
5651  */
5652 static void check_declarations(void)
5653 {
5654         if (warning.unused_parameter) {
5655                 const scope_t *scope = &current_function->parameters;
5656
5657                 /* do not issue unused warnings for main */
5658                 if (!is_sym_main(current_function->base.base.symbol)) {
5659                         warn_unused_entity(scope->entities, NULL);
5660                 }
5661         }
5662         if (warning.unused_variable) {
5663                 walk_statements(current_function->statement, check_unused_variables,
5664                                 NULL);
5665         }
5666 }
5667
5668 static int determine_truth(expression_t const* const cond)
5669 {
5670         return
5671                 !is_constant_expression(cond) ? 0 :
5672                 fold_constant(cond) != 0      ? 1 :
5673                 -1;
5674 }
5675
5676 static void check_reachable(statement_t *);
5677 static bool reaches_end;
5678
5679 static bool expression_returns(expression_t const *const expr)
5680 {
5681         switch (expr->kind) {
5682                 case EXPR_CALL: {
5683                         expression_t const *const func = expr->call.function;
5684                         if (func->kind == EXPR_REFERENCE) {
5685                                 entity_t *entity = func->reference.entity;
5686                                 if (entity->kind == ENTITY_FUNCTION
5687                                                 && entity->declaration.modifiers & DM_NORETURN)
5688                                         return false;
5689                         }
5690
5691                         if (!expression_returns(func))
5692                                 return false;
5693
5694                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
5695                                 if (!expression_returns(arg->expression))
5696                                         return false;
5697                         }
5698
5699                         return true;
5700                 }
5701
5702                 case EXPR_REFERENCE:
5703                 case EXPR_REFERENCE_ENUM_VALUE:
5704                 case EXPR_CONST:
5705                 case EXPR_CHARACTER_CONSTANT:
5706                 case EXPR_WIDE_CHARACTER_CONSTANT:
5707                 case EXPR_STRING_LITERAL:
5708                 case EXPR_WIDE_STRING_LITERAL:
5709                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
5710                 case EXPR_LABEL_ADDRESS:
5711                 case EXPR_CLASSIFY_TYPE:
5712                 case EXPR_SIZEOF: // TODO handle obscure VLA case
5713                 case EXPR_ALIGNOF:
5714                 case EXPR_FUNCNAME:
5715                 case EXPR_BUILTIN_CONSTANT_P:
5716                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
5717                 case EXPR_OFFSETOF:
5718                 case EXPR_INVALID:
5719                         return true;
5720
5721                 case EXPR_STATEMENT: {
5722                         bool old_reaches_end = reaches_end;
5723                         reaches_end = false;
5724                         check_reachable(expr->statement.statement);
5725                         bool returns = reaches_end;
5726                         reaches_end = old_reaches_end;
5727                         return returns;
5728                 }
5729
5730                 case EXPR_CONDITIONAL:
5731                         // TODO handle constant expression
5732
5733                         if (!expression_returns(expr->conditional.condition))
5734                                 return false;
5735
5736                         if (expr->conditional.true_expression != NULL
5737                                         && expression_returns(expr->conditional.true_expression))
5738                                 return true;
5739
5740                         return expression_returns(expr->conditional.false_expression);
5741
5742                 case EXPR_SELECT:
5743                         return expression_returns(expr->select.compound);
5744
5745                 case EXPR_ARRAY_ACCESS:
5746                         return
5747                                 expression_returns(expr->array_access.array_ref) &&
5748                                 expression_returns(expr->array_access.index);
5749
5750                 case EXPR_VA_START:
5751                         return expression_returns(expr->va_starte.ap);
5752
5753                 case EXPR_VA_ARG:
5754                         return expression_returns(expr->va_arge.ap);
5755
5756                 EXPR_UNARY_CASES_MANDATORY
5757                         return expression_returns(expr->unary.value);
5758
5759                 case EXPR_UNARY_THROW:
5760                         return false;
5761
5762                 EXPR_BINARY_CASES
5763                         // TODO handle constant lhs of && and ||
5764                         return
5765                                 expression_returns(expr->binary.left) &&
5766                                 expression_returns(expr->binary.right);
5767
5768                 case EXPR_UNKNOWN:
5769                         break;
5770         }
5771
5772         panic("unhandled expression");
5773 }
5774
5775 static bool initializer_returns(initializer_t const *const init)
5776 {
5777         switch (init->kind) {
5778                 case INITIALIZER_VALUE:
5779                         return expression_returns(init->value.value);
5780
5781                 case INITIALIZER_LIST: {
5782                         initializer_t * const*       i       = init->list.initializers;
5783                         initializer_t * const* const end     = i + init->list.len;
5784                         bool                         returns = true;
5785                         for (; i != end; ++i) {
5786                                 if (!initializer_returns(*i))
5787                                         returns = false;
5788                         }
5789                         return returns;
5790                 }
5791
5792                 case INITIALIZER_STRING:
5793                 case INITIALIZER_WIDE_STRING:
5794                 case INITIALIZER_DESIGNATOR: // designators have no payload
5795                         return true;
5796         }
5797         panic("unhandled initializer");
5798 }
5799
5800 static bool noreturn_candidate;
5801
5802 static void check_reachable(statement_t *const stmt)
5803 {
5804         if (stmt->base.reachable)
5805                 return;
5806         if (stmt->kind != STATEMENT_DO_WHILE)
5807                 stmt->base.reachable = true;
5808
5809         statement_t *last = stmt;
5810         statement_t *next;
5811         switch (stmt->kind) {
5812                 case STATEMENT_INVALID:
5813                 case STATEMENT_EMPTY:
5814                 case STATEMENT_ASM:
5815                         next = stmt->base.next;
5816                         break;
5817
5818                 case STATEMENT_DECLARATION: {
5819                         declaration_statement_t const *const decl = &stmt->declaration;
5820                         entity_t                const *      ent  = decl->declarations_begin;
5821                         entity_t                const *const last = decl->declarations_end;
5822                         if (ent != NULL) {
5823                                 for (;; ent = ent->base.next) {
5824                                         if (ent->kind                 == ENTITY_VARIABLE &&
5825                                                         ent->variable.initializer != NULL            &&
5826                                                         !initializer_returns(ent->variable.initializer)) {
5827                                                 return;
5828                                         }
5829                                         if (ent == last)
5830                                                 break;
5831                                 }
5832                         }
5833                         next = stmt->base.next;
5834                         break;
5835                 }
5836
5837                 case STATEMENT_COMPOUND:
5838                         next = stmt->compound.statements;
5839                         if (next == NULL)
5840                                 next = stmt->base.next;
5841                         break;
5842
5843                 case STATEMENT_RETURN: {
5844                         expression_t const *const val = stmt->returns.value;
5845                         if (val == NULL || expression_returns(val))
5846                                 noreturn_candidate = false;
5847                         return;
5848                 }
5849
5850                 case STATEMENT_IF: {
5851                         if_statement_t const *const ifs  = &stmt->ifs;
5852                         expression_t   const *const cond = ifs->condition;
5853
5854                         if (!expression_returns(cond))
5855                                 return;
5856
5857                         int const val = determine_truth(cond);
5858
5859                         if (val >= 0)
5860                                 check_reachable(ifs->true_statement);
5861
5862                         if (val > 0)
5863                                 return;
5864
5865                         if (ifs->false_statement != NULL) {
5866                                 check_reachable(ifs->false_statement);
5867                                 return;
5868                         }
5869
5870                         next = stmt->base.next;
5871                         break;
5872                 }
5873
5874                 case STATEMENT_SWITCH: {
5875                         switch_statement_t const *const switchs = &stmt->switchs;
5876                         expression_t       const *const expr    = switchs->expression;
5877
5878                         if (!expression_returns(expr))
5879                                 return;
5880
5881                         if (is_constant_expression(expr)) {
5882                                 long                    const val      = fold_constant(expr);
5883                                 case_label_statement_t *      defaults = NULL;
5884                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5885                                         if (i->expression == NULL) {
5886                                                 defaults = i;
5887                                                 continue;
5888                                         }
5889
5890                                         if (i->first_case <= val && val <= i->last_case) {
5891                                                 check_reachable((statement_t*)i);
5892                                                 return;
5893                                         }
5894                                 }
5895
5896                                 if (defaults != NULL) {
5897                                         check_reachable((statement_t*)defaults);
5898                                         return;
5899                                 }
5900                         } else {
5901                                 bool has_default = false;
5902                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5903                                         if (i->expression == NULL)
5904                                                 has_default = true;
5905
5906                                         check_reachable((statement_t*)i);
5907                                 }
5908
5909                                 if (has_default)
5910                                         return;
5911                         }
5912
5913                         next = stmt->base.next;
5914                         break;
5915                 }
5916
5917                 case STATEMENT_EXPRESSION: {
5918                         /* Check for noreturn function call */
5919                         expression_t const *const expr = stmt->expression.expression;
5920                         if (!expression_returns(expr))
5921                                 return;
5922
5923                         next = stmt->base.next;
5924                         break;
5925                 }
5926
5927                 case STATEMENT_CONTINUE: {
5928                         statement_t *parent = stmt;
5929                         for (;;) {
5930                                 parent = parent->base.parent;
5931                                 if (parent == NULL) /* continue not within loop */
5932                                         return;
5933
5934                                 next = parent;
5935                                 switch (parent->kind) {
5936                                         case STATEMENT_WHILE:    goto continue_while;
5937                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5938                                         case STATEMENT_FOR:      goto continue_for;
5939
5940                                         default: break;
5941                                 }
5942                         }
5943                 }
5944
5945                 case STATEMENT_BREAK: {
5946                         statement_t *parent = stmt;
5947                         for (;;) {
5948                                 parent = parent->base.parent;
5949                                 if (parent == NULL) /* break not within loop/switch */
5950                                         return;
5951
5952                                 switch (parent->kind) {
5953                                         case STATEMENT_SWITCH:
5954                                         case STATEMENT_WHILE:
5955                                         case STATEMENT_DO_WHILE:
5956                                         case STATEMENT_FOR:
5957                                                 last = parent;
5958                                                 next = parent->base.next;
5959                                                 goto found_break_parent;
5960
5961                                         default: break;
5962                                 }
5963                         }
5964 found_break_parent:
5965                         break;
5966                 }
5967
5968                 case STATEMENT_GOTO:
5969                         if (stmt->gotos.expression) {
5970                                 if (!expression_returns(stmt->gotos.expression))
5971                                         return;
5972
5973                                 statement_t *parent = stmt->base.parent;
5974                                 if (parent == NULL) /* top level goto */
5975                                         return;
5976                                 next = parent;
5977                         } else {
5978                                 next = stmt->gotos.label->statement;
5979                                 if (next == NULL) /* missing label */
5980                                         return;
5981                         }
5982                         break;
5983
5984                 case STATEMENT_LABEL:
5985                         next = stmt->label.statement;
5986                         break;
5987
5988                 case STATEMENT_CASE_LABEL:
5989                         next = stmt->case_label.statement;
5990                         break;
5991
5992                 case STATEMENT_WHILE: {
5993                         while_statement_t const *const whiles = &stmt->whiles;
5994                         expression_t      const *const cond   = whiles->condition;
5995
5996                         if (!expression_returns(cond))
5997                                 return;
5998
5999                         int const val = determine_truth(cond);
6000
6001                         if (val >= 0)
6002                                 check_reachable(whiles->body);
6003
6004                         if (val > 0)
6005                                 return;
6006
6007                         next = stmt->base.next;
6008                         break;
6009                 }
6010
6011                 case STATEMENT_DO_WHILE:
6012                         next = stmt->do_while.body;
6013                         break;
6014
6015                 case STATEMENT_FOR: {
6016                         for_statement_t *const fors = &stmt->fors;
6017
6018                         if (fors->condition_reachable)
6019                                 return;
6020                         fors->condition_reachable = true;
6021
6022                         expression_t const *const cond = fors->condition;
6023
6024                         int val;
6025                         if (cond == NULL) {
6026                                 val = 1;
6027                         } else if (expression_returns(cond)) {
6028                                 val = determine_truth(cond);
6029                         } else {
6030                                 return;
6031                         }
6032
6033                         if (val >= 0)
6034                                 check_reachable(fors->body);
6035
6036                         if (val > 0)
6037                                 return;
6038
6039                         next = stmt->base.next;
6040                         break;
6041                 }
6042
6043                 case STATEMENT_MS_TRY: {
6044                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
6045                         check_reachable(ms_try->try_statement);
6046                         next = ms_try->final_statement;
6047                         break;
6048                 }
6049
6050                 case STATEMENT_LEAVE: {
6051                         statement_t *parent = stmt;
6052                         for (;;) {
6053                                 parent = parent->base.parent;
6054                                 if (parent == NULL) /* __leave not within __try */
6055                                         return;
6056
6057                                 if (parent->kind == STATEMENT_MS_TRY) {
6058                                         last = parent;
6059                                         next = parent->ms_try.final_statement;
6060                                         break;
6061                                 }
6062                         }
6063                         break;
6064                 }
6065
6066                 default:
6067                         panic("invalid statement kind");
6068         }
6069
6070         while (next == NULL) {
6071                 next = last->base.parent;
6072                 if (next == NULL) {
6073                         noreturn_candidate = false;
6074
6075                         type_t *const type = skip_typeref(current_function->base.type);
6076                         assert(is_type_function(type));
6077                         type_t *const ret  = skip_typeref(type->function.return_type);
6078                         if (warning.return_type                    &&
6079                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
6080                             is_type_valid(ret)                     &&
6081                             !is_sym_main(current_function->base.base.symbol)) {
6082                                 warningf(&stmt->base.source_position,
6083                                          "control reaches end of non-void function");
6084                         }
6085                         return;
6086                 }
6087
6088                 switch (next->kind) {
6089                         case STATEMENT_INVALID:
6090                         case STATEMENT_EMPTY:
6091                         case STATEMENT_DECLARATION:
6092                         case STATEMENT_EXPRESSION:
6093                         case STATEMENT_ASM:
6094                         case STATEMENT_RETURN:
6095                         case STATEMENT_CONTINUE:
6096                         case STATEMENT_BREAK:
6097                         case STATEMENT_GOTO:
6098                         case STATEMENT_LEAVE:
6099                                 panic("invalid control flow in function");
6100
6101                         case STATEMENT_COMPOUND:
6102                                 if (next->compound.stmt_expr) {
6103                                         reaches_end = true;
6104                                         return;
6105                                 }
6106                                 /* FALLTHROUGH */
6107                         case STATEMENT_IF:
6108                         case STATEMENT_SWITCH:
6109                         case STATEMENT_LABEL:
6110                         case STATEMENT_CASE_LABEL:
6111                                 last = next;
6112                                 next = next->base.next;
6113                                 break;
6114
6115                         case STATEMENT_WHILE: {
6116 continue_while:
6117                                 if (next->base.reachable)
6118                                         return;
6119                                 next->base.reachable = true;
6120
6121                                 while_statement_t const *const whiles = &next->whiles;
6122                                 expression_t      const *const cond   = whiles->condition;
6123
6124                                 if (!expression_returns(cond))
6125                                         return;
6126
6127                                 int const val = determine_truth(cond);
6128
6129                                 if (val >= 0)
6130                                         check_reachable(whiles->body);
6131
6132                                 if (val > 0)
6133                                         return;
6134
6135                                 last = next;
6136                                 next = next->base.next;
6137                                 break;
6138                         }
6139
6140                         case STATEMENT_DO_WHILE: {
6141 continue_do_while:
6142                                 if (next->base.reachable)
6143                                         return;
6144                                 next->base.reachable = true;
6145
6146                                 do_while_statement_t const *const dw   = &next->do_while;
6147                                 expression_t         const *const cond = dw->condition;
6148
6149                                 if (!expression_returns(cond))
6150                                         return;
6151
6152                                 int const val = determine_truth(cond);
6153
6154                                 if (val >= 0)
6155                                         check_reachable(dw->body);
6156
6157                                 if (val > 0)
6158                                         return;
6159
6160                                 last = next;
6161                                 next = next->base.next;
6162                                 break;
6163                         }
6164
6165                         case STATEMENT_FOR: {
6166 continue_for:;
6167                                 for_statement_t *const fors = &next->fors;
6168
6169                                 fors->step_reachable = true;
6170
6171                                 if (fors->condition_reachable)
6172                                         return;
6173                                 fors->condition_reachable = true;
6174
6175                                 expression_t const *const cond = fors->condition;
6176
6177                                 int val;
6178                                 if (cond == NULL) {
6179                                         val = 1;
6180                                 } else if (expression_returns(cond)) {
6181                                         val = determine_truth(cond);
6182                                 } else {
6183                                         return;
6184                                 }
6185
6186                                 if (val >= 0)
6187                                         check_reachable(fors->body);
6188
6189                                 if (val > 0)
6190                                         return;
6191
6192                                 last = next;
6193                                 next = next->base.next;
6194                                 break;
6195                         }
6196
6197                         case STATEMENT_MS_TRY:
6198                                 last = next;
6199                                 next = next->ms_try.final_statement;
6200                                 break;
6201                 }
6202         }
6203
6204         check_reachable(next);
6205 }
6206
6207 static void check_unreachable(statement_t* const stmt, void *const env)
6208 {
6209         (void)env;
6210
6211         switch (stmt->kind) {
6212                 case STATEMENT_DO_WHILE:
6213                         if (!stmt->base.reachable) {
6214                                 expression_t const *const cond = stmt->do_while.condition;
6215                                 if (determine_truth(cond) >= 0) {
6216                                         warningf(&cond->base.source_position,
6217                                                  "condition of do-while-loop is unreachable");
6218                                 }
6219                         }
6220                         return;
6221
6222                 case STATEMENT_FOR: {
6223                         for_statement_t const* const fors = &stmt->fors;
6224
6225                         // if init and step are unreachable, cond is unreachable, too
6226                         if (!stmt->base.reachable && !fors->step_reachable) {
6227                                 warningf(&stmt->base.source_position, "statement is unreachable");
6228                         } else {
6229                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
6230                                         warningf(&fors->initialisation->base.source_position,
6231                                                  "initialisation of for-statement is unreachable");
6232                                 }
6233
6234                                 if (!fors->condition_reachable && fors->condition != NULL) {
6235                                         warningf(&fors->condition->base.source_position,
6236                                                  "condition of for-statement is unreachable");
6237                                 }
6238
6239                                 if (!fors->step_reachable && fors->step != NULL) {
6240                                         warningf(&fors->step->base.source_position,
6241                                                  "step of for-statement is unreachable");
6242                                 }
6243                         }
6244                         return;
6245                 }
6246
6247                 case STATEMENT_COMPOUND:
6248                         if (stmt->compound.statements != NULL)
6249                                 return;
6250                         goto warn_unreachable;
6251
6252                 case STATEMENT_DECLARATION: {
6253                         /* Only warn if there is at least one declarator with an initializer.
6254                          * This typically occurs in switch statements. */
6255                         declaration_statement_t const *const decl = &stmt->declaration;
6256                         entity_t                const *      ent  = decl->declarations_begin;
6257                         entity_t                const *const last = decl->declarations_end;
6258                         if (ent != NULL) {
6259                                 for (;; ent = ent->base.next) {
6260                                         if (ent->kind                 == ENTITY_VARIABLE &&
6261                                                         ent->variable.initializer != NULL) {
6262                                                 goto warn_unreachable;
6263                                         }
6264                                         if (ent == last)
6265                                                 return;
6266                                 }
6267                         }
6268                 }
6269
6270                 default:
6271 warn_unreachable:
6272                         if (!stmt->base.reachable)
6273                                 warningf(&stmt->base.source_position, "statement is unreachable");
6274                         return;
6275         }
6276 }
6277
6278 static void parse_external_declaration(void)
6279 {
6280         /* function-definitions and declarations both start with declaration
6281          * specifiers */
6282         declaration_specifiers_t specifiers;
6283         memset(&specifiers, 0, sizeof(specifiers));
6284
6285         add_anchor_token(';');
6286         parse_declaration_specifiers(&specifiers);
6287         rem_anchor_token(';');
6288
6289         /* must be a declaration */
6290         if (token.type == ';') {
6291                 parse_anonymous_declaration_rest(&specifiers);
6292                 return;
6293         }
6294
6295         add_anchor_token(',');
6296         add_anchor_token('=');
6297         add_anchor_token(';');
6298         add_anchor_token('{');
6299
6300         /* declarator is common to both function-definitions and declarations */
6301         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
6302
6303         rem_anchor_token('{');
6304         rem_anchor_token(';');
6305         rem_anchor_token('=');
6306         rem_anchor_token(',');
6307
6308         /* must be a declaration */
6309         switch (token.type) {
6310                 case ',':
6311                 case ';':
6312                 case '=':
6313                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
6314                                         DECL_FLAGS_NONE);
6315                         return;
6316         }
6317
6318         /* must be a function definition */
6319         parse_kr_declaration_list(ndeclaration);
6320
6321         if (token.type != '{') {
6322                 parse_error_expected("while parsing function definition", '{', NULL);
6323                 eat_until_matching_token(';');
6324                 return;
6325         }
6326
6327         assert(is_declaration(ndeclaration));
6328         type_t *const orig_type = ndeclaration->declaration.type;
6329         type_t *      type      = skip_typeref(orig_type);
6330
6331         if (!is_type_function(type)) {
6332                 if (is_type_valid(type)) {
6333                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
6334                                type, ndeclaration->base.symbol);
6335                 }
6336                 eat_block();
6337                 return;
6338         } else if (is_typeref(orig_type)) {
6339                 /* §6.9.1:2 */
6340                 errorf(&ndeclaration->base.source_position,
6341                                 "type of function definition '%#T' is a typedef",
6342                                 orig_type, ndeclaration->base.symbol);
6343         }
6344
6345         if (warning.aggregate_return &&
6346             is_type_compound(skip_typeref(type->function.return_type))) {
6347                 warningf(HERE, "function '%Y' returns an aggregate",
6348                          ndeclaration->base.symbol);
6349         }
6350         if (warning.traditional && !type->function.unspecified_parameters) {
6351                 warningf(HERE, "traditional C rejects ISO C style function definition of function '%Y'",
6352                         ndeclaration->base.symbol);
6353         }
6354         if (warning.old_style_definition && type->function.unspecified_parameters) {
6355                 warningf(HERE, "old-style function definition '%Y'",
6356                         ndeclaration->base.symbol);
6357         }
6358
6359         /* §6.7.5.3:14 a function definition with () means no
6360          * parameters (and not unspecified parameters) */
6361         if (type->function.unspecified_parameters &&
6362                         type->function.parameters == NULL     &&
6363                         !type->function.kr_style_parameters) {
6364                 type_t *copy                          = duplicate_type(type);
6365                 copy->function.unspecified_parameters = false;
6366                 type                                  = identify_new_type(copy);
6367
6368                 ndeclaration->declaration.type = type;
6369         }
6370
6371         entity_t *const entity = record_entity(ndeclaration, true);
6372         assert(entity->kind == ENTITY_FUNCTION);
6373         assert(ndeclaration->kind == ENTITY_FUNCTION);
6374
6375         function_t *function = &entity->function;
6376         if (ndeclaration != entity) {
6377                 function->parameters = ndeclaration->function.parameters;
6378         }
6379         assert(is_declaration(entity));
6380         type = skip_typeref(entity->declaration.type);
6381
6382         /* push function parameters and switch scope */
6383         size_t const  top       = environment_top();
6384         scope_t      *old_scope = scope_push(&function->parameters);
6385
6386         entity_t *parameter = function->parameters.entities;
6387         for (; parameter != NULL; parameter = parameter->base.next) {
6388                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
6389                         parameter->base.parent_scope = current_scope;
6390                 }
6391                 assert(parameter->base.parent_scope == NULL
6392                                 || parameter->base.parent_scope == current_scope);
6393                 parameter->base.parent_scope = current_scope;
6394                 if (parameter->base.symbol == NULL) {
6395                         errorf(&parameter->base.source_position, "parameter name omitted");
6396                         continue;
6397                 }
6398                 environment_push(parameter);
6399         }
6400
6401         if (function->statement != NULL) {
6402                 parser_error_multiple_definition(entity, HERE);
6403                 eat_block();
6404         } else {
6405                 /* parse function body */
6406                 int         label_stack_top      = label_top();
6407                 function_t *old_current_function = current_function;
6408                 current_function                 = function;
6409                 current_parent                   = NULL;
6410
6411                 goto_first   = NULL;
6412                 goto_anchor  = &goto_first;
6413                 label_first  = NULL;
6414                 label_anchor = &label_first;
6415
6416                 statement_t *const body = parse_compound_statement(false);
6417                 function->statement = body;
6418                 first_err = true;
6419                 check_labels();
6420                 check_declarations();
6421                 if (warning.return_type      ||
6422                     warning.unreachable_code ||
6423                     (warning.missing_noreturn
6424                      && !(function->base.modifiers & DM_NORETURN))) {
6425                         noreturn_candidate = true;
6426                         check_reachable(body);
6427                         if (warning.unreachable_code)
6428                                 walk_statements(body, check_unreachable, NULL);
6429                         if (warning.missing_noreturn &&
6430                             noreturn_candidate       &&
6431                             !(function->base.modifiers & DM_NORETURN)) {
6432                                 warningf(&body->base.source_position,
6433                                          "function '%#T' is candidate for attribute 'noreturn'",
6434                                          type, entity->base.symbol);
6435                         }
6436                 }
6437
6438                 assert(current_parent   == NULL);
6439                 assert(current_function == function);
6440                 current_function = old_current_function;
6441                 label_pop_to(label_stack_top);
6442         }
6443
6444         assert(current_scope == &function->parameters);
6445         scope_pop(old_scope);
6446         environment_pop_to(top);
6447 }
6448
6449 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
6450                                   source_position_t *source_position,
6451                                   const symbol_t *symbol)
6452 {
6453         type_t *type = allocate_type_zero(TYPE_BITFIELD);
6454
6455         type->bitfield.base_type       = base_type;
6456         type->bitfield.size_expression = size;
6457
6458         il_size_t bit_size;
6459         type_t *skipped_type = skip_typeref(base_type);
6460         if (!is_type_integer(skipped_type)) {
6461                 errorf(HERE, "bitfield base type '%T' is not an integer type",
6462                         base_type);
6463                 bit_size = 0;
6464         } else {
6465                 bit_size = skipped_type->base.size * 8;
6466         }
6467
6468         if (is_constant_expression(size)) {
6469                 long v = fold_constant(size);
6470
6471                 if (v < 0) {
6472                         errorf(source_position, "negative width in bit-field '%Y'", symbol);
6473                 } else if (v == 0) {
6474                         errorf(source_position, "zero width for bit-field '%Y'", symbol);
6475                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
6476                         errorf(source_position, "width of '%Y' exceeds its type", symbol);
6477                 } else {
6478                         type->bitfield.bit_size = v;
6479                 }
6480         }
6481
6482         return type;
6483 }
6484
6485 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
6486 {
6487         entity_t *iter = compound->members.entities;
6488         for (; iter != NULL; iter = iter->base.next) {
6489                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
6490                         continue;
6491
6492                 if (iter->base.symbol == symbol) {
6493                         return iter;
6494                 } else if (iter->base.symbol == NULL) {
6495                         type_t *type = skip_typeref(iter->declaration.type);
6496                         if (is_type_compound(type)) {
6497                                 entity_t *result
6498                                         = find_compound_entry(type->compound.compound, symbol);
6499                                 if (result != NULL)
6500                                         return result;
6501                         }
6502                         continue;
6503                 }
6504         }
6505
6506         return NULL;
6507 }
6508
6509 static void parse_compound_declarators(compound_t *compound,
6510                 const declaration_specifiers_t *specifiers)
6511 {
6512         while (true) {
6513                 entity_t *entity;
6514
6515                 if (token.type == ':') {
6516                         source_position_t source_position = *HERE;
6517                         next_token();
6518
6519                         type_t *base_type = specifiers->type;
6520                         expression_t *size = parse_constant_expression();
6521
6522                         type_t *type = make_bitfield_type(base_type, size,
6523                                         &source_position, sym_anonymous);
6524
6525                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
6526                         entity->base.namespc                       = NAMESPACE_NORMAL;
6527                         entity->base.source_position               = source_position;
6528                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
6529                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
6530                         entity->declaration.modifiers              = specifiers->modifiers;
6531                         entity->declaration.type                   = type;
6532                         append_entity(&compound->members, entity);
6533                 } else {
6534                         entity = parse_declarator(specifiers,
6535                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
6536                         if (entity->kind == ENTITY_TYPEDEF) {
6537                                 errorf(&entity->base.source_position,
6538                                                 "typedef not allowed as compound member");
6539                         } else {
6540                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
6541
6542                                 /* make sure we don't define a symbol multiple times */
6543                                 symbol_t *symbol = entity->base.symbol;
6544                                 if (symbol != NULL) {
6545                                         entity_t *prev = find_compound_entry(compound, symbol);
6546                                         if (prev != NULL) {
6547                                                 errorf(&entity->base.source_position,
6548                                                                 "multiple declarations of symbol '%Y' (declared %P)",
6549                                                                 symbol, &prev->base.source_position);
6550                                         }
6551                                 }
6552
6553                                 if (token.type == ':') {
6554                                         source_position_t source_position = *HERE;
6555                                         next_token();
6556                                         expression_t *size = parse_constant_expression();
6557
6558                                         type_t *type          = entity->declaration.type;
6559                                         type_t *bitfield_type = make_bitfield_type(type, size,
6560                                                         &source_position, entity->base.symbol);
6561                                         entity->declaration.type = bitfield_type;
6562                                 } else {
6563                                         type_t *orig_type = entity->declaration.type;
6564                                         type_t *type      = skip_typeref(orig_type);
6565                                         if (is_type_function(type)) {
6566                                                 errorf(&entity->base.source_position,
6567                                                                 "compound member '%Y' must not have function type '%T'",
6568                                                                 entity->base.symbol, orig_type);
6569                                         } else if (is_type_incomplete(type)) {
6570                                                 /* §6.7.2.1:16 flexible array member */
6571                                                 if (!is_type_array(type)       ||
6572                                                                 token.type          != ';' ||
6573                                                                 look_ahead(1)->type != '}') {
6574                                                         errorf(&entity->base.source_position,
6575                                                                         "compound member '%Y' has incomplete type '%T'",
6576                                                                         entity->base.symbol, orig_type);
6577                                                 }
6578                                         }
6579                                 }
6580
6581                                 append_entity(&compound->members, entity);
6582                         }
6583                 }
6584
6585                 if (token.type != ',')
6586                         break;
6587                 next_token();
6588         }
6589         expect(';', end_error);
6590
6591 end_error:
6592         anonymous_entity = NULL;
6593 }
6594
6595 static void parse_compound_type_entries(compound_t *compound)
6596 {
6597         eat('{');
6598         add_anchor_token('}');
6599
6600         while (token.type != '}') {
6601                 if (token.type == T_EOF) {
6602                         errorf(HERE, "EOF while parsing struct");
6603                         break;
6604                 }
6605                 declaration_specifiers_t specifiers;
6606                 memset(&specifiers, 0, sizeof(specifiers));
6607                 parse_declaration_specifiers(&specifiers);
6608
6609                 parse_compound_declarators(compound, &specifiers);
6610         }
6611         rem_anchor_token('}');
6612         next_token();
6613
6614         /* §6.7.2.1:7 */
6615         compound->complete = true;
6616 }
6617
6618 static type_t *parse_typename(void)
6619 {
6620         declaration_specifiers_t specifiers;
6621         memset(&specifiers, 0, sizeof(specifiers));
6622         parse_declaration_specifiers(&specifiers);
6623         if (specifiers.storage_class != STORAGE_CLASS_NONE ||
6624                         specifiers.thread_local) {
6625                 /* TODO: improve error message, user does probably not know what a
6626                  * storage class is...
6627                  */
6628                 errorf(HERE, "typename may not have a storage class");
6629         }
6630
6631         type_t *result = parse_abstract_declarator(specifiers.type);
6632
6633         return result;
6634 }
6635
6636
6637
6638
6639 typedef expression_t* (*parse_expression_function)(void);
6640 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
6641
6642 typedef struct expression_parser_function_t expression_parser_function_t;
6643 struct expression_parser_function_t {
6644         parse_expression_function        parser;
6645         precedence_t                     infix_precedence;
6646         parse_expression_infix_function  infix_parser;
6647 };
6648
6649 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
6650
6651 /**
6652  * Prints an error message if an expression was expected but not read
6653  */
6654 static expression_t *expected_expression_error(void)
6655 {
6656         /* skip the error message if the error token was read */
6657         if (token.type != T_ERROR) {
6658                 errorf(HERE, "expected expression, got token %K", &token);
6659         }
6660         next_token();
6661
6662         return create_invalid_expression();
6663 }
6664
6665 /**
6666  * Parse a string constant.
6667  */
6668 static expression_t *parse_string_const(void)
6669 {
6670         wide_string_t wres;
6671         if (token.type == T_STRING_LITERAL) {
6672                 string_t res = token.v.string;
6673                 next_token();
6674                 while (token.type == T_STRING_LITERAL) {
6675                         res = concat_strings(&res, &token.v.string);
6676                         next_token();
6677                 }
6678                 if (token.type != T_WIDE_STRING_LITERAL) {
6679                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
6680                         /* note: that we use type_char_ptr here, which is already the
6681                          * automatic converted type. revert_automatic_type_conversion
6682                          * will construct the array type */
6683                         cnst->base.type    = warning.write_strings ? type_const_char_ptr : type_char_ptr;
6684                         cnst->string.value = res;
6685                         return cnst;
6686                 }
6687
6688                 wres = concat_string_wide_string(&res, &token.v.wide_string);
6689         } else {
6690                 wres = token.v.wide_string;
6691         }
6692         next_token();
6693
6694         for (;;) {
6695                 switch (token.type) {
6696                         case T_WIDE_STRING_LITERAL:
6697                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
6698                                 break;
6699
6700                         case T_STRING_LITERAL:
6701                                 wres = concat_wide_string_string(&wres, &token.v.string);
6702                                 break;
6703
6704                         default: {
6705                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6706                                 cnst->base.type         = warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6707                                 cnst->wide_string.value = wres;
6708                                 return cnst;
6709                         }
6710                 }
6711                 next_token();
6712         }
6713 }
6714
6715 /**
6716  * Parse a boolean constant.
6717  */
6718 static expression_t *parse_bool_const(bool value)
6719 {
6720         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6721         cnst->base.type          = type_bool;
6722         cnst->conste.v.int_value = value;
6723
6724         next_token();
6725
6726         return cnst;
6727 }
6728
6729 /**
6730  * Parse an integer constant.
6731  */
6732 static expression_t *parse_int_const(void)
6733 {
6734         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
6735         cnst->base.type          = token.datatype;
6736         cnst->conste.v.int_value = token.v.intvalue;
6737
6738         next_token();
6739
6740         return cnst;
6741 }
6742
6743 /**
6744  * Parse a character constant.
6745  */
6746 static expression_t *parse_character_constant(void)
6747 {
6748         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
6749         cnst->base.type          = token.datatype;
6750         cnst->conste.v.character = token.v.string;
6751
6752         if (cnst->conste.v.character.size != 1) {
6753                 if (!GNU_MODE) {
6754                         errorf(HERE, "more than 1 character in character constant");
6755                 } else if (warning.multichar) {
6756                         warningf(HERE, "multi-character character constant");
6757                 }
6758         }
6759         next_token();
6760
6761         return cnst;
6762 }
6763
6764 /**
6765  * Parse a wide character constant.
6766  */
6767 static expression_t *parse_wide_character_constant(void)
6768 {
6769         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
6770         cnst->base.type               = token.datatype;
6771         cnst->conste.v.wide_character = token.v.wide_string;
6772
6773         if (cnst->conste.v.wide_character.size != 1) {
6774                 if (!GNU_MODE) {
6775                         errorf(HERE, "more than 1 character in character constant");
6776                 } else if (warning.multichar) {
6777                         warningf(HERE, "multi-character character constant");
6778                 }
6779         }
6780         next_token();
6781
6782         return cnst;
6783 }
6784
6785 /**
6786  * Parse a float constant.
6787  */
6788 static expression_t *parse_float_const(void)
6789 {
6790         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
6791         cnst->base.type            = token.datatype;
6792         cnst->conste.v.float_value = token.v.floatvalue;
6793
6794         next_token();
6795
6796         return cnst;
6797 }
6798
6799 static entity_t *create_implicit_function(symbol_t *symbol,
6800                 const source_position_t *source_position)
6801 {
6802         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6803         ntype->function.return_type            = type_int;
6804         ntype->function.unspecified_parameters = true;
6805         ntype->function.linkage                = LINKAGE_C;
6806         type_t *type                           = identify_new_type(ntype);
6807
6808         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6809         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6810         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6811         entity->declaration.type                   = type;
6812         entity->declaration.implicit               = true;
6813         entity->base.symbol                        = symbol;
6814         entity->base.source_position               = *source_position;
6815
6816         bool strict_prototypes_old = warning.strict_prototypes;
6817         warning.strict_prototypes  = false;
6818         record_entity(entity, false);
6819         warning.strict_prototypes = strict_prototypes_old;
6820
6821         return entity;
6822 }
6823
6824 /**
6825  * Creates a return_type (func)(argument_type) function type if not
6826  * already exists.
6827  */
6828 static type_t *make_function_2_type(type_t *return_type, type_t *argument_type1,
6829                                     type_t *argument_type2)
6830 {
6831         function_parameter_t *const parameter2 = allocate_parameter(argument_type2);
6832         function_parameter_t *const parameter1 = allocate_parameter(argument_type1);
6833         parameter1->next = parameter2;
6834
6835         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6836         type->function.return_type = return_type;
6837         type->function.parameters  = parameter1;
6838
6839         return identify_new_type(type);
6840 }
6841
6842 /**
6843  * Creates a return_type (func)(argument_type) function type if not
6844  * already exists.
6845  *
6846  * @param return_type    the return type
6847  * @param argument_type  the argument type
6848  */
6849 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
6850 {
6851         function_parameter_t *const parameter = allocate_parameter(argument_type);
6852
6853         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6854         type->function.return_type = return_type;
6855         type->function.parameters  = parameter;
6856
6857         return identify_new_type(type);
6858 }
6859
6860 static type_t *make_function_1_type_variadic(type_t *return_type, type_t *argument_type)
6861 {
6862         type_t *res = make_function_1_type(return_type, argument_type);
6863         res->function.variadic = 1;
6864         return res;
6865 }
6866
6867 /**
6868  * Creates a return_type (func)(void) function type if not
6869  * already exists.
6870  *
6871  * @param return_type    the return type
6872  */
6873 static type_t *make_function_0_type(type_t *return_type)
6874 {
6875         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6876         type->function.return_type = return_type;
6877         type->function.parameters  = NULL;
6878
6879         return identify_new_type(type);
6880 }
6881
6882 /**
6883  * Creates a NO_RETURN return_type (func)(void) function type if not
6884  * already exists.
6885  *
6886  * @param return_type    the return type
6887  */
6888 static type_t *make_function_0_type_noreturn(type_t *return_type)
6889 {
6890         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
6891         type->function.return_type = return_type;
6892         type->function.parameters  = NULL;
6893         type->function.base.modifiers |= DM_NORETURN;
6894         return type;
6895
6896         return identify_new_type(type);
6897 }
6898
6899 /**
6900  * Performs automatic type cast as described in §6.3.2.1.
6901  *
6902  * @param orig_type  the original type
6903  */
6904 static type_t *automatic_type_conversion(type_t *orig_type)
6905 {
6906         type_t *type = skip_typeref(orig_type);
6907         if (is_type_array(type)) {
6908                 array_type_t *array_type   = &type->array;
6909                 type_t       *element_type = array_type->element_type;
6910                 unsigned      qualifiers   = array_type->base.qualifiers;
6911
6912                 return make_pointer_type(element_type, qualifiers);
6913         }
6914
6915         if (is_type_function(type)) {
6916                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6917         }
6918
6919         return orig_type;
6920 }
6921
6922 /**
6923  * reverts the automatic casts of array to pointer types and function
6924  * to function-pointer types as defined §6.3.2.1
6925  */
6926 type_t *revert_automatic_type_conversion(const expression_t *expression)
6927 {
6928         switch (expression->kind) {
6929                 case EXPR_REFERENCE: {
6930                         entity_t *entity = expression->reference.entity;
6931                         if (is_declaration(entity)) {
6932                                 return entity->declaration.type;
6933                         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6934                                 return entity->enum_value.enum_type;
6935                         } else {
6936                                 panic("no declaration or enum in reference");
6937                         }
6938                 }
6939
6940                 case EXPR_SELECT: {
6941                         entity_t *entity = expression->select.compound_entry;
6942                         assert(is_declaration(entity));
6943                         type_t   *type   = entity->declaration.type;
6944                         return get_qualified_type(type,
6945                                         expression->base.type->base.qualifiers);
6946                 }
6947
6948                 case EXPR_UNARY_DEREFERENCE: {
6949                         const expression_t *const value = expression->unary.value;
6950                         type_t             *const type  = skip_typeref(value->base.type);
6951                         if (!is_type_pointer(type))
6952                                 return type_error_type;
6953                         return type->pointer.points_to;
6954                 }
6955
6956                 case EXPR_ARRAY_ACCESS: {
6957                         const expression_t *array_ref = expression->array_access.array_ref;
6958                         type_t             *type_left = skip_typeref(array_ref->base.type);
6959                         if (!is_type_pointer(type_left))
6960                                 return type_error_type;
6961                         return type_left->pointer.points_to;
6962                 }
6963
6964                 case EXPR_STRING_LITERAL: {
6965                         size_t size = expression->string.value.size;
6966                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6967                 }
6968
6969                 case EXPR_WIDE_STRING_LITERAL: {
6970                         size_t size = expression->wide_string.value.size;
6971                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6972                 }
6973
6974                 case EXPR_COMPOUND_LITERAL:
6975                         return expression->compound_literal.type;
6976
6977                 default:
6978                         return expression->base.type;
6979         }
6980 }
6981
6982 static expression_t *parse_reference(void)
6983 {
6984         symbol_t *const symbol = token.v.symbol;
6985
6986         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
6987
6988         if (entity == NULL) {
6989                 if (!strict_mode && look_ahead(1)->type == '(') {
6990                         /* an implicitly declared function */
6991                         if (warning.error_implicit_function_declaration) {
6992                                 errorf(HERE, "implicit declaration of function '%Y'", symbol);
6993                         } else if (warning.implicit_function_declaration) {
6994                                 warningf(HERE, "implicit declaration of function '%Y'", symbol);
6995                         }
6996
6997                         entity = create_implicit_function(symbol, HERE);
6998                 } else {
6999                         errorf(HERE, "unknown identifier '%Y' found.", symbol);
7000                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
7001                 }
7002         }
7003
7004         type_t *orig_type;
7005
7006         if (is_declaration(entity)) {
7007                 orig_type = entity->declaration.type;
7008         } else if (entity->kind == ENTITY_ENUM_VALUE) {
7009                 orig_type = entity->enum_value.enum_type;
7010         } else if (entity->kind == ENTITY_TYPEDEF) {
7011                 errorf(HERE, "encountered typedef name '%Y' while parsing expression",
7012                         symbol);
7013                 next_token();
7014                 return create_invalid_expression();
7015         } else {
7016                 panic("expected declaration or enum value in reference");
7017         }
7018
7019         /* we always do the auto-type conversions; the & and sizeof parser contains
7020          * code to revert this! */
7021         type_t *type = automatic_type_conversion(orig_type);
7022
7023         expression_kind_t kind = EXPR_REFERENCE;
7024         if (entity->kind == ENTITY_ENUM_VALUE)
7025                 kind = EXPR_REFERENCE_ENUM_VALUE;
7026
7027         expression_t *expression     = allocate_expression_zero(kind);
7028         expression->reference.entity = entity;
7029         expression->base.type        = type;
7030
7031         /* this declaration is used */
7032         if (is_declaration(entity)) {
7033                 entity->declaration.used = true;
7034         }
7035
7036         if (entity->base.parent_scope != file_scope
7037                 && entity->base.parent_scope->depth < current_function->parameters.depth
7038                 && is_type_valid(orig_type) && !is_type_function(orig_type)) {
7039                 if (entity->kind == ENTITY_VARIABLE) {
7040                         /* access of a variable from an outer function */
7041                         entity->variable.address_taken = true;
7042                 } else if (entity->kind == ENTITY_PARAMETER) {
7043                         entity->parameter.address_taken = true;
7044                 }
7045                 current_function->need_closure = true;
7046         }
7047
7048         /* check for deprecated functions */
7049         if (warning.deprecated_declarations
7050                 && is_declaration(entity)
7051                 && entity->declaration.modifiers & DM_DEPRECATED) {
7052                 declaration_t *declaration = &entity->declaration;
7053
7054                 char const *const prefix = entity->kind == ENTITY_FUNCTION ?
7055                         "function" : "variable";
7056
7057                 if (declaration->deprecated_string != NULL) {
7058                         warningf(HERE, "%s '%Y' is deprecated (declared %P): \"%s\"",
7059                                  prefix, entity->base.symbol, &entity->base.source_position,
7060                                  declaration->deprecated_string);
7061                 } else {
7062                         warningf(HERE, "%s '%Y' is deprecated (declared %P)", prefix,
7063                                  entity->base.symbol, &entity->base.source_position);
7064                 }
7065         }
7066
7067         if (warning.init_self && entity == current_init_decl && !in_type_prop
7068             && entity->kind == ENTITY_VARIABLE) {
7069                 current_init_decl = NULL;
7070                 warningf(HERE, "variable '%#T' is initialized by itself",
7071                          entity->declaration.type, entity->base.symbol);
7072         }
7073
7074         next_token();
7075         return expression;
7076 }
7077
7078 static bool semantic_cast(expression_t *cast)
7079 {
7080         expression_t            *expression      = cast->unary.value;
7081         type_t                  *orig_dest_type  = cast->base.type;
7082         type_t                  *orig_type_right = expression->base.type;
7083         type_t            const *dst_type        = skip_typeref(orig_dest_type);
7084         type_t            const *src_type        = skip_typeref(orig_type_right);
7085         source_position_t const *pos             = &cast->base.source_position;
7086
7087         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
7088         if (dst_type == type_void)
7089                 return true;
7090
7091         /* only integer and pointer can be casted to pointer */
7092         if (is_type_pointer(dst_type)  &&
7093             !is_type_pointer(src_type) &&
7094             !is_type_integer(src_type) &&
7095             is_type_valid(src_type)) {
7096                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
7097                 return false;
7098         }
7099
7100         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
7101                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
7102                 return false;
7103         }
7104
7105         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
7106                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
7107                 return false;
7108         }
7109
7110         if (warning.cast_qual &&
7111             is_type_pointer(src_type) &&
7112             is_type_pointer(dst_type)) {
7113                 type_t *src = skip_typeref(src_type->pointer.points_to);
7114                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
7115                 unsigned missing_qualifiers =
7116                         src->base.qualifiers & ~dst->base.qualifiers;
7117                 if (missing_qualifiers != 0) {
7118                         warningf(pos,
7119                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
7120                                  missing_qualifiers, orig_type_right);
7121                 }
7122         }
7123         return true;
7124 }
7125
7126 static expression_t *parse_compound_literal(type_t *type)
7127 {
7128         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
7129
7130         parse_initializer_env_t env;
7131         env.type             = type;
7132         env.entity           = NULL;
7133         env.must_be_constant = false;
7134         initializer_t *initializer = parse_initializer(&env);
7135         type = env.type;
7136
7137         expression->compound_literal.initializer = initializer;
7138         expression->compound_literal.type        = type;
7139         expression->base.type                    = automatic_type_conversion(type);
7140
7141         return expression;
7142 }
7143
7144 /**
7145  * Parse a cast expression.
7146  */
7147 static expression_t *parse_cast(void)
7148 {
7149         add_anchor_token(')');
7150
7151         source_position_t source_position = token.source_position;
7152
7153         type_t *type = parse_typename();
7154
7155         rem_anchor_token(')');
7156         expect(')', end_error);
7157
7158         if (token.type == '{') {
7159                 return parse_compound_literal(type);
7160         }
7161
7162         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
7163         cast->base.source_position = source_position;
7164
7165         expression_t *value = parse_sub_expression(PREC_CAST);
7166         cast->base.type   = type;
7167         cast->unary.value = value;
7168
7169         if (! semantic_cast(cast)) {
7170                 /* TODO: record the error in the AST. else it is impossible to detect it */
7171         }
7172
7173         return cast;
7174 end_error:
7175         return create_invalid_expression();
7176 }
7177
7178 /**
7179  * Parse a statement expression.
7180  */
7181 static expression_t *parse_statement_expression(void)
7182 {
7183         add_anchor_token(')');
7184
7185         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
7186
7187         statement_t *statement          = parse_compound_statement(true);
7188         statement->compound.stmt_expr   = true;
7189         expression->statement.statement = statement;
7190
7191         /* find last statement and use its type */
7192         type_t *type = type_void;
7193         const statement_t *stmt = statement->compound.statements;
7194         if (stmt != NULL) {
7195                 while (stmt->base.next != NULL)
7196                         stmt = stmt->base.next;
7197
7198                 if (stmt->kind == STATEMENT_EXPRESSION) {
7199                         type = stmt->expression.expression->base.type;
7200                 }
7201         } else if (warning.other) {
7202                 warningf(&expression->base.source_position, "empty statement expression ({})");
7203         }
7204         expression->base.type = type;
7205
7206         rem_anchor_token(')');
7207         expect(')', end_error);
7208
7209 end_error:
7210         return expression;
7211 }
7212
7213 /**
7214  * Parse a parenthesized expression.
7215  */
7216 static expression_t *parse_parenthesized_expression(void)
7217 {
7218         eat('(');
7219
7220         switch (token.type) {
7221         case '{':
7222                 /* gcc extension: a statement expression */
7223                 return parse_statement_expression();
7224
7225         TYPE_QUALIFIERS
7226         TYPE_SPECIFIERS
7227                 return parse_cast();
7228         case T_IDENTIFIER:
7229                 if (is_typedef_symbol(token.v.symbol)) {
7230                         return parse_cast();
7231                 }
7232         }
7233
7234         add_anchor_token(')');
7235         expression_t *result = parse_expression();
7236         result->base.parenthesized = true;
7237         rem_anchor_token(')');
7238         expect(')', end_error);
7239
7240 end_error:
7241         return result;
7242 }
7243
7244 static expression_t *parse_function_keyword(void)
7245 {
7246         /* TODO */
7247
7248         if (current_function == NULL) {
7249                 errorf(HERE, "'__func__' used outside of a function");
7250         }
7251
7252         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7253         expression->base.type     = type_char_ptr;
7254         expression->funcname.kind = FUNCNAME_FUNCTION;
7255
7256         next_token();
7257
7258         return expression;
7259 }
7260
7261 static expression_t *parse_pretty_function_keyword(void)
7262 {
7263         if (current_function == NULL) {
7264                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
7265         }
7266
7267         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7268         expression->base.type     = type_char_ptr;
7269         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
7270
7271         eat(T___PRETTY_FUNCTION__);
7272
7273         return expression;
7274 }
7275
7276 static expression_t *parse_funcsig_keyword(void)
7277 {
7278         if (current_function == NULL) {
7279                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
7280         }
7281
7282         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7283         expression->base.type     = type_char_ptr;
7284         expression->funcname.kind = FUNCNAME_FUNCSIG;
7285
7286         eat(T___FUNCSIG__);
7287
7288         return expression;
7289 }
7290
7291 static expression_t *parse_funcdname_keyword(void)
7292 {
7293         if (current_function == NULL) {
7294                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
7295         }
7296
7297         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
7298         expression->base.type     = type_char_ptr;
7299         expression->funcname.kind = FUNCNAME_FUNCDNAME;
7300
7301         eat(T___FUNCDNAME__);
7302
7303         return expression;
7304 }
7305
7306 static designator_t *parse_designator(void)
7307 {
7308         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
7309         result->source_position = *HERE;
7310
7311         if (token.type != T_IDENTIFIER) {
7312                 parse_error_expected("while parsing member designator",
7313                                      T_IDENTIFIER, NULL);
7314                 return NULL;
7315         }
7316         result->symbol = token.v.symbol;
7317         next_token();
7318
7319         designator_t *last_designator = result;
7320         while (true) {
7321                 if (token.type == '.') {
7322                         next_token();
7323                         if (token.type != T_IDENTIFIER) {
7324                                 parse_error_expected("while parsing member designator",
7325                                                      T_IDENTIFIER, NULL);
7326                                 return NULL;
7327                         }
7328                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7329                         designator->source_position = *HERE;
7330                         designator->symbol          = token.v.symbol;
7331                         next_token();
7332
7333                         last_designator->next = designator;
7334                         last_designator       = designator;
7335                         continue;
7336                 }
7337                 if (token.type == '[') {
7338                         next_token();
7339                         add_anchor_token(']');
7340                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
7341                         designator->source_position = *HERE;
7342                         designator->array_index     = parse_expression();
7343                         rem_anchor_token(']');
7344                         expect(']', end_error);
7345                         if (designator->array_index == NULL) {
7346                                 return NULL;
7347                         }
7348
7349                         last_designator->next = designator;
7350                         last_designator       = designator;
7351                         continue;
7352                 }
7353                 break;
7354         }
7355
7356         return result;
7357 end_error:
7358         return NULL;
7359 }
7360
7361 /**
7362  * Parse the __builtin_offsetof() expression.
7363  */
7364 static expression_t *parse_offsetof(void)
7365 {
7366         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
7367         expression->base.type    = type_size_t;
7368
7369         eat(T___builtin_offsetof);
7370
7371         expect('(', end_error);
7372         add_anchor_token(',');
7373         type_t *type = parse_typename();
7374         rem_anchor_token(',');
7375         expect(',', end_error);
7376         add_anchor_token(')');
7377         designator_t *designator = parse_designator();
7378         rem_anchor_token(')');
7379         expect(')', end_error);
7380
7381         expression->offsetofe.type       = type;
7382         expression->offsetofe.designator = designator;
7383
7384         type_path_t path;
7385         memset(&path, 0, sizeof(path));
7386         path.top_type = type;
7387         path.path     = NEW_ARR_F(type_path_entry_t, 0);
7388
7389         descend_into_subtype(&path);
7390
7391         if (!walk_designator(&path, designator, true)) {
7392                 return create_invalid_expression();
7393         }
7394
7395         DEL_ARR_F(path.path);
7396
7397         return expression;
7398 end_error:
7399         return create_invalid_expression();
7400 }
7401
7402 /**
7403  * Parses a _builtin_va_start() expression.
7404  */
7405 static expression_t *parse_va_start(void)
7406 {
7407         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
7408
7409         eat(T___builtin_va_start);
7410
7411         expect('(', end_error);
7412         add_anchor_token(',');
7413         expression->va_starte.ap = parse_assignment_expression();
7414         rem_anchor_token(',');
7415         expect(',', end_error);
7416         expression_t *const expr = parse_assignment_expression();
7417         if (expr->kind == EXPR_REFERENCE) {
7418                 entity_t *const entity = expr->reference.entity;
7419                 if (entity->base.parent_scope != &current_function->parameters
7420                                 || entity->base.next != NULL
7421                                 || entity->kind != ENTITY_PARAMETER) {
7422                         errorf(&expr->base.source_position,
7423                                "second argument of 'va_start' must be last parameter of the current function");
7424                 } else {
7425                         expression->va_starte.parameter = &entity->variable;
7426                 }
7427                 expect(')', end_error);
7428                 return expression;
7429         }
7430         expect(')', end_error);
7431 end_error:
7432         return create_invalid_expression();
7433 }
7434
7435 /**
7436  * Parses a _builtin_va_arg() expression.
7437  */
7438 static expression_t *parse_va_arg(void)
7439 {
7440         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
7441
7442         eat(T___builtin_va_arg);
7443
7444         expect('(', end_error);
7445         expression->va_arge.ap = parse_assignment_expression();
7446         expect(',', end_error);
7447         expression->base.type = parse_typename();
7448         expect(')', end_error);
7449
7450         return expression;
7451 end_error:
7452         return create_invalid_expression();
7453 }
7454
7455 /**
7456  * Parses a __builtin_constant_p() expression.
7457  */
7458 static expression_t *parse_builtin_constant(void)
7459 {
7460         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
7461
7462         eat(T___builtin_constant_p);
7463
7464         expect('(', end_error);
7465         add_anchor_token(')');
7466         expression->builtin_constant.value = parse_assignment_expression();
7467         rem_anchor_token(')');
7468         expect(')', end_error);
7469         expression->base.type = type_int;
7470
7471         return expression;
7472 end_error:
7473         return create_invalid_expression();
7474 }
7475
7476 /**
7477  * Parses a __builtin_types_compatible_p() expression.
7478  */
7479 static expression_t *parse_builtin_types_compatible(void)
7480 {
7481         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
7482
7483         eat(T___builtin_types_compatible_p);
7484
7485         expect('(', end_error);
7486         add_anchor_token(')');
7487         add_anchor_token(',');
7488         expression->builtin_types_compatible.left = parse_typename();
7489         rem_anchor_token(',');
7490         expect(',', end_error);
7491         expression->builtin_types_compatible.right = parse_typename();
7492         rem_anchor_token(')');
7493         expect(')', end_error);
7494         expression->base.type = type_int;
7495
7496         return expression;
7497 end_error:
7498         return create_invalid_expression();
7499 }
7500
7501 /**
7502  * Parses a __builtin_is_*() compare expression.
7503  */
7504 static expression_t *parse_compare_builtin(void)
7505 {
7506         expression_t *expression;
7507
7508         switch (token.type) {
7509         case T___builtin_isgreater:
7510                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
7511                 break;
7512         case T___builtin_isgreaterequal:
7513                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
7514                 break;
7515         case T___builtin_isless:
7516                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
7517                 break;
7518         case T___builtin_islessequal:
7519                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
7520                 break;
7521         case T___builtin_islessgreater:
7522                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
7523                 break;
7524         case T___builtin_isunordered:
7525                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
7526                 break;
7527         default:
7528                 internal_errorf(HERE, "invalid compare builtin found");
7529         }
7530         expression->base.source_position = *HERE;
7531         next_token();
7532
7533         expect('(', end_error);
7534         expression->binary.left = parse_assignment_expression();
7535         expect(',', end_error);
7536         expression->binary.right = parse_assignment_expression();
7537         expect(')', end_error);
7538
7539         type_t *const orig_type_left  = expression->binary.left->base.type;
7540         type_t *const orig_type_right = expression->binary.right->base.type;
7541
7542         type_t *const type_left  = skip_typeref(orig_type_left);
7543         type_t *const type_right = skip_typeref(orig_type_right);
7544         if (!is_type_float(type_left) && !is_type_float(type_right)) {
7545                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7546                         type_error_incompatible("invalid operands in comparison",
7547                                 &expression->base.source_position, orig_type_left, orig_type_right);
7548                 }
7549         } else {
7550                 semantic_comparison(&expression->binary);
7551         }
7552
7553         return expression;
7554 end_error:
7555         return create_invalid_expression();
7556 }
7557
7558 #if 0
7559 /**
7560  * Parses a __builtin_expect(, end_error) expression.
7561  */
7562 static expression_t *parse_builtin_expect(void, end_error)
7563 {
7564         expression_t *expression
7565                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
7566
7567         eat(T___builtin_expect);
7568
7569         expect('(', end_error);
7570         expression->binary.left = parse_assignment_expression();
7571         expect(',', end_error);
7572         expression->binary.right = parse_constant_expression();
7573         expect(')', end_error);
7574
7575         expression->base.type = expression->binary.left->base.type;
7576
7577         return expression;
7578 end_error:
7579         return create_invalid_expression();
7580 }
7581 #endif
7582
7583 /**
7584  * Parses a MS assume() expression.
7585  */
7586 static expression_t *parse_assume(void)
7587 {
7588         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7589
7590         eat(T__assume);
7591
7592         expect('(', end_error);
7593         add_anchor_token(')');
7594         expression->unary.value = parse_assignment_expression();
7595         rem_anchor_token(')');
7596         expect(')', end_error);
7597
7598         expression->base.type = type_void;
7599         return expression;
7600 end_error:
7601         return create_invalid_expression();
7602 }
7603
7604 /**
7605  * Return the declaration for a given label symbol or create a new one.
7606  *
7607  * @param symbol  the symbol of the label
7608  */
7609 static label_t *get_label(symbol_t *symbol)
7610 {
7611         entity_t *label;
7612         assert(current_function != NULL);
7613
7614         label = get_entity(symbol, NAMESPACE_LABEL);
7615         /* if we found a local label, we already created the declaration */
7616         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7617                 if (label->base.parent_scope != current_scope) {
7618                         assert(label->base.parent_scope->depth < current_scope->depth);
7619                         current_function->goto_to_outer = true;
7620                 }
7621                 return &label->label;
7622         }
7623
7624         label = get_entity(symbol, NAMESPACE_LABEL);
7625         /* if we found a label in the same function, then we already created the
7626          * declaration */
7627         if (label != NULL
7628                         && label->base.parent_scope == &current_function->parameters) {
7629                 return &label->label;
7630         }
7631
7632         /* otherwise we need to create a new one */
7633         label               = allocate_entity_zero(ENTITY_LABEL);
7634         label->base.namespc = NAMESPACE_LABEL;
7635         label->base.symbol  = symbol;
7636
7637         label_push(label);
7638
7639         return &label->label;
7640 }
7641
7642 /**
7643  * Parses a GNU && label address expression.
7644  */
7645 static expression_t *parse_label_address(void)
7646 {
7647         source_position_t source_position = token.source_position;
7648         eat(T_ANDAND);
7649         if (token.type != T_IDENTIFIER) {
7650                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7651                 goto end_error;
7652         }
7653         symbol_t *symbol = token.v.symbol;
7654         next_token();
7655
7656         label_t *label       = get_label(symbol);
7657         label->used          = true;
7658         label->address_taken = true;
7659
7660         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7661         expression->base.source_position = source_position;
7662
7663         /* label address is threaten as a void pointer */
7664         expression->base.type           = type_void_ptr;
7665         expression->label_address.label = label;
7666         return expression;
7667 end_error:
7668         return create_invalid_expression();
7669 }
7670
7671 /**
7672  * Parse a microsoft __noop expression.
7673  */
7674 static expression_t *parse_noop_expression(void)
7675 {
7676         /* the result is a (int)0 */
7677         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
7678         cnst->base.type            = type_int;
7679         cnst->conste.v.int_value   = 0;
7680         cnst->conste.is_ms_noop    = true;
7681
7682         eat(T___noop);
7683
7684         if (token.type == '(') {
7685                 /* parse arguments */
7686                 eat('(');
7687                 add_anchor_token(')');
7688                 add_anchor_token(',');
7689
7690                 if (token.type != ')') {
7691                         while (true) {
7692                                 (void)parse_assignment_expression();
7693                                 if (token.type != ',')
7694                                         break;
7695                                 next_token();
7696                         }
7697                 }
7698         }
7699         rem_anchor_token(',');
7700         rem_anchor_token(')');
7701         expect(')', end_error);
7702
7703 end_error:
7704         return cnst;
7705 }
7706
7707 /**
7708  * Parses a primary expression.
7709  */
7710 static expression_t *parse_primary_expression(void)
7711 {
7712         switch (token.type) {
7713                 case T_false:                        return parse_bool_const(false);
7714                 case T_true:                         return parse_bool_const(true);
7715                 case T_INTEGER:                      return parse_int_const();
7716                 case T_CHARACTER_CONSTANT:           return parse_character_constant();
7717                 case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7718                 case T_FLOATINGPOINT:                return parse_float_const();
7719                 case T_STRING_LITERAL:
7720                 case T_WIDE_STRING_LITERAL:          return parse_string_const();
7721                 case T_IDENTIFIER:                   return parse_reference();
7722                 case T___FUNCTION__:
7723                 case T___func__:                     return parse_function_keyword();
7724                 case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7725                 case T___FUNCSIG__:                  return parse_funcsig_keyword();
7726                 case T___FUNCDNAME__:                return parse_funcdname_keyword();
7727                 case T___builtin_offsetof:           return parse_offsetof();
7728                 case T___builtin_va_start:           return parse_va_start();
7729                 case T___builtin_va_arg:             return parse_va_arg();
7730                 case T___builtin_isgreater:
7731                 case T___builtin_isgreaterequal:
7732                 case T___builtin_isless:
7733                 case T___builtin_islessequal:
7734                 case T___builtin_islessgreater:
7735                 case T___builtin_isunordered:        return parse_compare_builtin();
7736                 case T___builtin_constant_p:         return parse_builtin_constant();
7737                 case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7738                 case T__assume:                      return parse_assume();
7739                 case T_ANDAND:
7740                         if (GNU_MODE)
7741                                 return parse_label_address();
7742                         break;
7743
7744                 case '(':                            return parse_parenthesized_expression();
7745                 case T___noop:                       return parse_noop_expression();
7746         }
7747
7748         errorf(HERE, "unexpected token %K, expected an expression", &token);
7749         return create_invalid_expression();
7750 }
7751
7752 /**
7753  * Check if the expression has the character type and issue a warning then.
7754  */
7755 static void check_for_char_index_type(const expression_t *expression)
7756 {
7757         type_t       *const type      = expression->base.type;
7758         const type_t *const base_type = skip_typeref(type);
7759
7760         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
7761                         warning.char_subscripts) {
7762                 warningf(&expression->base.source_position,
7763                          "array subscript has type '%T'", type);
7764         }
7765 }
7766
7767 static expression_t *parse_array_expression(expression_t *left)
7768 {
7769         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7770
7771         eat('[');
7772         add_anchor_token(']');
7773
7774         expression_t *inside = parse_expression();
7775
7776         type_t *const orig_type_left   = left->base.type;
7777         type_t *const orig_type_inside = inside->base.type;
7778
7779         type_t *const type_left   = skip_typeref(orig_type_left);
7780         type_t *const type_inside = skip_typeref(orig_type_inside);
7781
7782         type_t                    *return_type;
7783         array_access_expression_t *array_access = &expression->array_access;
7784         if (is_type_pointer(type_left)) {
7785                 return_type             = type_left->pointer.points_to;
7786                 array_access->array_ref = left;
7787                 array_access->index     = inside;
7788                 check_for_char_index_type(inside);
7789         } else if (is_type_pointer(type_inside)) {
7790                 return_type             = type_inside->pointer.points_to;
7791                 array_access->array_ref = inside;
7792                 array_access->index     = left;
7793                 array_access->flipped   = true;
7794                 check_for_char_index_type(left);
7795         } else {
7796                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7797                         errorf(HERE,
7798                                 "array access on object with non-pointer types '%T', '%T'",
7799                                 orig_type_left, orig_type_inside);
7800                 }
7801                 return_type             = type_error_type;
7802                 array_access->array_ref = left;
7803                 array_access->index     = inside;
7804         }
7805
7806         expression->base.type = automatic_type_conversion(return_type);
7807
7808         rem_anchor_token(']');
7809         expect(']', end_error);
7810 end_error:
7811         return expression;
7812 }
7813
7814 static expression_t *parse_typeprop(expression_kind_t const kind)
7815 {
7816         expression_t  *tp_expression = allocate_expression_zero(kind);
7817         tp_expression->base.type     = type_size_t;
7818
7819         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7820
7821         /* we only refer to a type property, mark this case */
7822         bool old     = in_type_prop;
7823         in_type_prop = true;
7824
7825         type_t       *orig_type;
7826         expression_t *expression;
7827         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7828                 next_token();
7829                 add_anchor_token(')');
7830                 orig_type = parse_typename();
7831                 rem_anchor_token(')');
7832                 expect(')', end_error);
7833
7834                 if (token.type == '{') {
7835                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7836                          * starting with a compound literal */
7837                         expression = parse_compound_literal(orig_type);
7838                         goto typeprop_expression;
7839                 }
7840         } else {
7841                 expression = parse_sub_expression(PREC_UNARY);
7842
7843 typeprop_expression:
7844                 tp_expression->typeprop.tp_expression = expression;
7845
7846                 orig_type = revert_automatic_type_conversion(expression);
7847                 expression->base.type = orig_type;
7848         }
7849
7850         tp_expression->typeprop.type   = orig_type;
7851         type_t const* const type       = skip_typeref(orig_type);
7852         char   const* const wrong_type =
7853                 GNU_MODE && is_type_atomic(type, ATOMIC_TYPE_VOID) ? NULL                  :
7854                 is_type_incomplete(type)                           ? "incomplete"          :
7855                 type->kind == TYPE_FUNCTION                        ? "function designator" :
7856                 type->kind == TYPE_BITFIELD                        ? "bitfield"            :
7857                 NULL;
7858         if (wrong_type != NULL) {
7859                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7860                 errorf(&tp_expression->base.source_position,
7861                                 "operand of %s expression must not be of %s type '%T'",
7862                                 what, wrong_type, orig_type);
7863         }
7864
7865 end_error:
7866         in_type_prop = old;
7867         return tp_expression;
7868 }
7869
7870 static expression_t *parse_sizeof(void)
7871 {
7872         return parse_typeprop(EXPR_SIZEOF);
7873 }
7874
7875 static expression_t *parse_alignof(void)
7876 {
7877         return parse_typeprop(EXPR_ALIGNOF);
7878 }
7879
7880 static expression_t *parse_select_expression(expression_t *compound)
7881 {
7882         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
7883         select->select.compound = compound;
7884
7885         assert(token.type == '.' || token.type == T_MINUSGREATER);
7886         bool is_pointer = (token.type == T_MINUSGREATER);
7887         next_token();
7888
7889         if (token.type != T_IDENTIFIER) {
7890                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7891                 return select;
7892         }
7893         symbol_t *symbol = token.v.symbol;
7894         next_token();
7895
7896         type_t *const orig_type = compound->base.type;
7897         type_t *const type      = skip_typeref(orig_type);
7898
7899         type_t *type_left;
7900         bool    saw_error = false;
7901         if (is_type_pointer(type)) {
7902                 if (!is_pointer) {
7903                         errorf(HERE,
7904                                "request for member '%Y' in something not a struct or union, but '%T'",
7905                                symbol, orig_type);
7906                         saw_error = true;
7907                 }
7908                 type_left = skip_typeref(type->pointer.points_to);
7909         } else {
7910                 if (is_pointer && is_type_valid(type)) {
7911                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7912                         saw_error = true;
7913                 }
7914                 type_left = type;
7915         }
7916
7917         entity_t *entry;
7918         if (type_left->kind == TYPE_COMPOUND_STRUCT ||
7919             type_left->kind == TYPE_COMPOUND_UNION) {
7920                 compound_t *compound = type_left->compound.compound;
7921
7922                 if (!compound->complete) {
7923                         errorf(HERE, "request for member '%Y' of incomplete type '%T'",
7924                                symbol, type_left);
7925                         goto create_error_entry;
7926                 }
7927
7928                 entry = find_compound_entry(compound, symbol);
7929                 if (entry == NULL) {
7930                         errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
7931                         goto create_error_entry;
7932                 }
7933         } else {
7934                 if (is_type_valid(type_left) && !saw_error) {
7935                         errorf(HERE,
7936                                "request for member '%Y' in something not a struct or union, but '%T'",
7937                                symbol, type_left);
7938                 }
7939 create_error_entry:
7940                 entry = create_error_entity(symbol, ENTITY_COMPOUND_MEMBER);
7941         }
7942
7943         assert(is_declaration(entry));
7944         select->select.compound_entry = entry;
7945
7946         type_t *entry_type = entry->declaration.type;
7947         type_t *res_type
7948                 = get_qualified_type(entry_type, type_left->base.qualifiers);
7949
7950         /* we always do the auto-type conversions; the & and sizeof parser contains
7951          * code to revert this! */
7952         select->base.type = automatic_type_conversion(res_type);
7953
7954         type_t *skipped = skip_typeref(res_type);
7955         if (skipped->kind == TYPE_BITFIELD) {
7956                 select->base.type = skipped->bitfield.base_type;
7957         }
7958
7959         return select;
7960 }
7961
7962 static void check_call_argument(const function_parameter_t *parameter,
7963                                 call_argument_t *argument, unsigned pos)
7964 {
7965         type_t         *expected_type      = parameter->type;
7966         type_t         *expected_type_skip = skip_typeref(expected_type);
7967         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7968         expression_t   *arg_expr           = argument->expression;
7969         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7970
7971         /* handle transparent union gnu extension */
7972         if (is_type_union(expected_type_skip)
7973                         && (expected_type_skip->base.modifiers
7974                                 & TYPE_MODIFIER_TRANSPARENT_UNION)) {
7975                 compound_t *union_decl  = expected_type_skip->compound.compound;
7976                 type_t     *best_type   = NULL;
7977                 entity_t   *entry       = union_decl->members.entities;
7978                 for ( ; entry != NULL; entry = entry->base.next) {
7979                         assert(is_declaration(entry));
7980                         type_t *decl_type = entry->declaration.type;
7981                         error = semantic_assign(decl_type, arg_expr);
7982                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7983                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7984                                 continue;
7985
7986                         if (error == ASSIGN_SUCCESS) {
7987                                 best_type = decl_type;
7988                         } else if (best_type == NULL) {
7989                                 best_type = decl_type;
7990                         }
7991                 }
7992
7993                 if (best_type != NULL) {
7994                         expected_type = best_type;
7995                 }
7996         }
7997
7998         error                = semantic_assign(expected_type, arg_expr);
7999         argument->expression = create_implicit_cast(argument->expression,
8000                                                     expected_type);
8001
8002         if (error != ASSIGN_SUCCESS) {
8003                 /* report exact scope in error messages (like "in argument 3") */
8004                 char buf[64];
8005                 snprintf(buf, sizeof(buf), "call argument %u", pos);
8006                 report_assign_error(error, expected_type, arg_expr,     buf,
8007                                                         &arg_expr->base.source_position);
8008         } else if (warning.traditional || warning.conversion) {
8009                 type_t *const promoted_type = get_default_promoted_type(arg_type);
8010                 if (!types_compatible(expected_type_skip, promoted_type) &&
8011                     !types_compatible(expected_type_skip, type_void_ptr) &&
8012                     !types_compatible(type_void_ptr,      promoted_type)) {
8013                         /* Deliberately show the skipped types in this warning */
8014                         warningf(&arg_expr->base.source_position,
8015                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
8016                                 pos, expected_type_skip, promoted_type);
8017                 }
8018         }
8019 }
8020
8021 /**
8022  * Handle the semantic restrictions of builtin calls
8023  */
8024 static void handle_builtin_argument_restrictions(call_expression_t *call) {
8025         switch (call->function->reference.entity->function.btk) {
8026                 case bk_gnu_builtin_return_address:
8027                 case bk_gnu_builtin_frame_address: {
8028                         /* argument must be constant */
8029                         call_argument_t *argument = call->arguments;
8030
8031                         if (! is_constant_expression(argument->expression)) {
8032                                 errorf(&call->base.source_position,
8033                                        "argument of '%Y' must be a constant expression",
8034                                        call->function->reference.entity->base.symbol);
8035                         }
8036                         break;
8037                 }
8038                 case bk_gnu_builtin_prefetch: {
8039                         /* second and third argument must be constant if existent */
8040                         call_argument_t *rw = call->arguments->next;
8041                         call_argument_t *locality = NULL;
8042
8043                         if (rw != NULL) {
8044                                 if (! is_constant_expression(rw->expression)) {
8045                                         errorf(&call->base.source_position,
8046                                                "second argument of '%Y' must be a constant expression",
8047                                                call->function->reference.entity->base.symbol);
8048                                 }
8049                                 locality = rw->next;
8050                         }
8051                         if (locality != NULL) {
8052                                 if (! is_constant_expression(locality->expression)) {
8053                                         errorf(&call->base.source_position,
8054                                                "third argument of '%Y' must be a constant expression",
8055                                                call->function->reference.entity->base.symbol);
8056                                 }
8057                                 locality = rw->next;
8058                         }
8059                         break;
8060                 }
8061                 default:
8062                         break;
8063         }
8064 }
8065
8066 /**
8067  * Parse a call expression, ie. expression '( ... )'.
8068  *
8069  * @param expression  the function address
8070  */
8071 static expression_t *parse_call_expression(expression_t *expression)
8072 {
8073         expression_t      *result = allocate_expression_zero(EXPR_CALL);
8074         call_expression_t *call   = &result->call;
8075         call->function            = expression;
8076
8077         type_t *const orig_type = expression->base.type;
8078         type_t *const type      = skip_typeref(orig_type);
8079
8080         function_type_t *function_type = NULL;
8081         if (is_type_pointer(type)) {
8082                 type_t *const to_type = skip_typeref(type->pointer.points_to);
8083
8084                 if (is_type_function(to_type)) {
8085                         function_type   = &to_type->function;
8086                         call->base.type = function_type->return_type;
8087                 }
8088         }
8089
8090         if (function_type == NULL && is_type_valid(type)) {
8091                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
8092         }
8093
8094         /* parse arguments */
8095         eat('(');
8096         add_anchor_token(')');
8097         add_anchor_token(',');
8098
8099         if (token.type != ')') {
8100                 call_argument_t *last_argument = NULL;
8101
8102                 while (true) {
8103                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8104
8105                         argument->expression = parse_assignment_expression();
8106                         if (last_argument == NULL) {
8107                                 call->arguments = argument;
8108                         } else {
8109                                 last_argument->next = argument;
8110                         }
8111                         last_argument = argument;
8112
8113                         if (token.type != ',')
8114                                 break;
8115                         next_token();
8116                 }
8117         }
8118         rem_anchor_token(',');
8119         rem_anchor_token(')');
8120         expect(')', end_error);
8121
8122         if (function_type == NULL)
8123                 return result;
8124
8125         function_parameter_t *parameter = function_type->parameters;
8126         call_argument_t      *argument  = call->arguments;
8127         if (!function_type->unspecified_parameters) {
8128                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
8129                                 parameter = parameter->next, argument = argument->next) {
8130                         check_call_argument(parameter, argument, ++pos);
8131                 }
8132
8133                 if (parameter != NULL) {
8134                         errorf(HERE, "too few arguments to function '%E'", expression);
8135                 } else if (argument != NULL && !function_type->variadic) {
8136                         errorf(HERE, "too many arguments to function '%E'", expression);
8137                 }
8138         }
8139
8140         /* do default promotion */
8141         for (; argument != NULL; argument = argument->next) {
8142                 type_t *type = argument->expression->base.type;
8143
8144                 type = get_default_promoted_type(type);
8145
8146                 argument->expression
8147                         = create_implicit_cast(argument->expression, type);
8148         }
8149
8150         check_format(&result->call);
8151
8152         if (warning.aggregate_return &&
8153             is_type_compound(skip_typeref(function_type->return_type))) {
8154                 warningf(&result->base.source_position,
8155                          "function call has aggregate value");
8156         }
8157
8158         if (call->function->kind == EXPR_REFERENCE) {
8159                 reference_expression_t *reference = &call->function->reference;
8160                 if (reference->entity->kind == ENTITY_FUNCTION &&
8161                     reference->entity->function.btk != bk_none)
8162                         handle_builtin_argument_restrictions(call);
8163         }
8164
8165 end_error:
8166         return result;
8167 }
8168
8169 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
8170
8171 static bool same_compound_type(const type_t *type1, const type_t *type2)
8172 {
8173         return
8174                 is_type_compound(type1) &&
8175                 type1->kind == type2->kind &&
8176                 type1->compound.compound == type2->compound.compound;
8177 }
8178
8179 static expression_t const *get_reference_address(expression_t const *expr)
8180 {
8181         bool regular_take_address = true;
8182         for (;;) {
8183                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8184                         expr = expr->unary.value;
8185                 } else {
8186                         regular_take_address = false;
8187                 }
8188
8189                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8190                         break;
8191
8192                 expr = expr->unary.value;
8193         }
8194
8195         if (expr->kind != EXPR_REFERENCE)
8196                 return NULL;
8197
8198         /* special case for functions which are automatically converted to a
8199          * pointer to function without an extra TAKE_ADDRESS operation */
8200         if (!regular_take_address &&
8201                         expr->reference.entity->kind != ENTITY_FUNCTION) {
8202                 return NULL;
8203         }
8204
8205         return expr;
8206 }
8207
8208 static void warn_reference_address_as_bool(expression_t const* expr)
8209 {
8210         if (!warning.address)
8211                 return;
8212
8213         expr = get_reference_address(expr);
8214         if (expr != NULL) {
8215                 warningf(&expr->base.source_position,
8216                          "the address of '%Y' will always evaluate as 'true'",
8217                          expr->reference.entity->base.symbol);
8218         }
8219 }
8220
8221 static void warn_assignment_in_condition(const expression_t *const expr)
8222 {
8223         if (!warning.parentheses)
8224                 return;
8225         if (expr->base.kind != EXPR_BINARY_ASSIGN)
8226                 return;
8227         if (expr->base.parenthesized)
8228                 return;
8229         warningf(&expr->base.source_position,
8230                         "suggest parentheses around assignment used as truth value");
8231 }
8232
8233 static void semantic_condition(expression_t const *const expr,
8234                                char const *const context)
8235 {
8236         type_t *const type = skip_typeref(expr->base.type);
8237         if (is_type_scalar(type)) {
8238                 warn_reference_address_as_bool(expr);
8239                 warn_assignment_in_condition(expr);
8240         } else if (is_type_valid(type)) {
8241                 errorf(&expr->base.source_position,
8242                                 "%s must have scalar type", context);
8243         }
8244 }
8245
8246 /**
8247  * Parse a conditional expression, ie. 'expression ? ... : ...'.
8248  *
8249  * @param expression  the conditional expression
8250  */
8251 static expression_t *parse_conditional_expression(expression_t *expression)
8252 {
8253         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
8254
8255         conditional_expression_t *conditional = &result->conditional;
8256         conditional->condition                = expression;
8257
8258         eat('?');
8259         add_anchor_token(':');
8260
8261         /* §6.5.15:2  The first operand shall have scalar type. */
8262         semantic_condition(expression, "condition of conditional operator");
8263
8264         expression_t *true_expression = expression;
8265         bool          gnu_cond = false;
8266         if (GNU_MODE && token.type == ':') {
8267                 gnu_cond = true;
8268         } else {
8269                 true_expression = parse_expression();
8270         }
8271         rem_anchor_token(':');
8272         expect(':', end_error);
8273 end_error:;
8274         expression_t *false_expression =
8275                 parse_sub_expression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
8276
8277         type_t *const orig_true_type  = true_expression->base.type;
8278         type_t *const orig_false_type = false_expression->base.type;
8279         type_t *const true_type       = skip_typeref(orig_true_type);
8280         type_t *const false_type      = skip_typeref(orig_false_type);
8281
8282         /* 6.5.15.3 */
8283         type_t *result_type;
8284         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8285                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
8286                 /* ISO/IEC 14882:1998(E) §5.16:2 */
8287                 if (true_expression->kind == EXPR_UNARY_THROW) {
8288                         result_type = false_type;
8289                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
8290                         result_type = true_type;
8291                 } else {
8292                         if (warning.other && (
8293                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
8294                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
8295                                         )) {
8296                                 warningf(&conditional->base.source_position,
8297                                                 "ISO C forbids conditional expression with only one void side");
8298                         }
8299                         result_type = type_void;
8300                 }
8301         } else if (is_type_arithmetic(true_type)
8302                    && is_type_arithmetic(false_type)) {
8303                 result_type = semantic_arithmetic(true_type, false_type);
8304
8305                 true_expression  = create_implicit_cast(true_expression, result_type);
8306                 false_expression = create_implicit_cast(false_expression, result_type);
8307
8308                 conditional->true_expression  = true_expression;
8309                 conditional->false_expression = false_expression;
8310                 conditional->base.type        = result_type;
8311         } else if (same_compound_type(true_type, false_type)) {
8312                 /* just take 1 of the 2 types */
8313                 result_type = true_type;
8314         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
8315                 type_t *pointer_type;
8316                 type_t *other_type;
8317                 expression_t *other_expression;
8318                 if (is_type_pointer(true_type) &&
8319                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
8320                         pointer_type     = true_type;
8321                         other_type       = false_type;
8322                         other_expression = false_expression;
8323                 } else {
8324                         pointer_type     = false_type;
8325                         other_type       = true_type;
8326                         other_expression = true_expression;
8327                 }
8328
8329                 if (is_null_pointer_constant(other_expression)) {
8330                         result_type = pointer_type;
8331                 } else if (is_type_pointer(other_type)) {
8332                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
8333                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
8334
8335                         type_t *to;
8336                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
8337                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
8338                                 to = type_void;
8339                         } else if (types_compatible(get_unqualified_type(to1),
8340                                                     get_unqualified_type(to2))) {
8341                                 to = to1;
8342                         } else {
8343                                 if (warning.other) {
8344                                         warningf(&conditional->base.source_position,
8345                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
8346                                                         true_type, false_type);
8347                                 }
8348                                 to = type_void;
8349                         }
8350
8351                         type_t *const type =
8352                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
8353                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
8354                 } else if (is_type_integer(other_type)) {
8355                         if (warning.other) {
8356                                 warningf(&conditional->base.source_position,
8357                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
8358                         }
8359                         result_type = pointer_type;
8360                 } else {
8361                         if (is_type_valid(other_type)) {
8362                                 type_error_incompatible("while parsing conditional",
8363                                                 &expression->base.source_position, true_type, false_type);
8364                         }
8365                         result_type = type_error_type;
8366                 }
8367         } else {
8368                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
8369                         type_error_incompatible("while parsing conditional",
8370                                                 &conditional->base.source_position, true_type,
8371                                                 false_type);
8372                 }
8373                 result_type = type_error_type;
8374         }
8375
8376         conditional->true_expression
8377                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
8378         conditional->false_expression
8379                 = create_implicit_cast(false_expression, result_type);
8380         conditional->base.type = result_type;
8381         return result;
8382 }
8383
8384 /**
8385  * Parse an extension expression.
8386  */
8387 static expression_t *parse_extension(void)
8388 {
8389         eat(T___extension__);
8390
8391         bool old_gcc_extension   = in_gcc_extension;
8392         in_gcc_extension         = true;
8393         expression_t *expression = parse_sub_expression(PREC_UNARY);
8394         in_gcc_extension         = old_gcc_extension;
8395         return expression;
8396 }
8397
8398 /**
8399  * Parse a __builtin_classify_type() expression.
8400  */
8401 static expression_t *parse_builtin_classify_type(void)
8402 {
8403         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
8404         result->base.type    = type_int;
8405
8406         eat(T___builtin_classify_type);
8407
8408         expect('(', end_error);
8409         add_anchor_token(')');
8410         expression_t *expression = parse_expression();
8411         rem_anchor_token(')');
8412         expect(')', end_error);
8413         result->classify_type.type_expression = expression;
8414
8415         return result;
8416 end_error:
8417         return create_invalid_expression();
8418 }
8419
8420 /**
8421  * Parse a delete expression
8422  * ISO/IEC 14882:1998(E) §5.3.5
8423  */
8424 static expression_t *parse_delete(void)
8425 {
8426         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
8427         result->base.type          = type_void;
8428
8429         eat(T_delete);
8430
8431         if (token.type == '[') {
8432                 next_token();
8433                 result->kind = EXPR_UNARY_DELETE_ARRAY;
8434                 expect(']', end_error);
8435 end_error:;
8436         }
8437
8438         expression_t *const value = parse_sub_expression(PREC_CAST);
8439         result->unary.value = value;
8440
8441         type_t *const type = skip_typeref(value->base.type);
8442         if (!is_type_pointer(type)) {
8443                 if (is_type_valid(type)) {
8444                         errorf(&value->base.source_position,
8445                                         "operand of delete must have pointer type");
8446                 }
8447         } else if (warning.other &&
8448                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
8449                 warningf(&value->base.source_position,
8450                                 "deleting 'void*' is undefined");
8451         }
8452
8453         return result;
8454 }
8455
8456 /**
8457  * Parse a throw expression
8458  * ISO/IEC 14882:1998(E) §15:1
8459  */
8460 static expression_t *parse_throw(void)
8461 {
8462         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
8463         result->base.type          = type_void;
8464
8465         eat(T_throw);
8466
8467         expression_t *value = NULL;
8468         switch (token.type) {
8469                 EXPRESSION_START {
8470                         value = parse_assignment_expression();
8471                         /* ISO/IEC 14882:1998(E) §15.1:3 */
8472                         type_t *const orig_type = value->base.type;
8473                         type_t *const type      = skip_typeref(orig_type);
8474                         if (is_type_incomplete(type)) {
8475                                 errorf(&value->base.source_position,
8476                                                 "cannot throw object of incomplete type '%T'", orig_type);
8477                         } else if (is_type_pointer(type)) {
8478                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
8479                                 if (is_type_incomplete(points_to) &&
8480                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8481                                         errorf(&value->base.source_position,
8482                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
8483                                 }
8484                         }
8485                 }
8486
8487                 default:
8488                         break;
8489         }
8490         result->unary.value = value;
8491
8492         return result;
8493 }
8494
8495 static bool check_pointer_arithmetic(const source_position_t *source_position,
8496                                      type_t *pointer_type,
8497                                      type_t *orig_pointer_type)
8498 {
8499         type_t *points_to = pointer_type->pointer.points_to;
8500         points_to = skip_typeref(points_to);
8501
8502         if (is_type_incomplete(points_to)) {
8503                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
8504                         errorf(source_position,
8505                                "arithmetic with pointer to incomplete type '%T' not allowed",
8506                                orig_pointer_type);
8507                         return false;
8508                 } else if (warning.pointer_arith) {
8509                         warningf(source_position,
8510                                  "pointer of type '%T' used in arithmetic",
8511                                  orig_pointer_type);
8512                 }
8513         } else if (is_type_function(points_to)) {
8514                 if (!GNU_MODE) {
8515                         errorf(source_position,
8516                                "arithmetic with pointer to function type '%T' not allowed",
8517                                orig_pointer_type);
8518                         return false;
8519                 } else if (warning.pointer_arith) {
8520                         warningf(source_position,
8521                                  "pointer to a function '%T' used in arithmetic",
8522                                  orig_pointer_type);
8523                 }
8524         }
8525         return true;
8526 }
8527
8528 static bool is_lvalue(const expression_t *expression)
8529 {
8530         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
8531         switch (expression->kind) {
8532         case EXPR_ARRAY_ACCESS:
8533         case EXPR_COMPOUND_LITERAL:
8534         case EXPR_REFERENCE:
8535         case EXPR_SELECT:
8536         case EXPR_UNARY_DEREFERENCE:
8537                 return true;
8538
8539         default: {
8540           type_t *type = skip_typeref(expression->base.type);
8541           return
8542                 /* ISO/IEC 14882:1998(E) §3.10:3 */
8543                 is_type_reference(type) ||
8544                 /* Claim it is an lvalue, if the type is invalid.  There was a parse
8545                  * error before, which maybe prevented properly recognizing it as
8546                  * lvalue. */
8547                 !is_type_valid(type);
8548         }
8549         }
8550 }
8551
8552 static void semantic_incdec(unary_expression_t *expression)
8553 {
8554         type_t *const orig_type = expression->value->base.type;
8555         type_t *const type      = skip_typeref(orig_type);
8556         if (is_type_pointer(type)) {
8557                 if (!check_pointer_arithmetic(&expression->base.source_position,
8558                                               type, orig_type)) {
8559                         return;
8560                 }
8561         } else if (!is_type_real(type) && is_type_valid(type)) {
8562                 /* TODO: improve error message */
8563                 errorf(&expression->base.source_position,
8564                        "operation needs an arithmetic or pointer type");
8565                 return;
8566         }
8567         if (!is_lvalue(expression->value)) {
8568                 /* TODO: improve error message */
8569                 errorf(&expression->base.source_position, "lvalue required as operand");
8570         }
8571         expression->base.type = orig_type;
8572 }
8573
8574 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8575 {
8576         type_t *const orig_type = expression->value->base.type;
8577         type_t *const type      = skip_typeref(orig_type);
8578         if (!is_type_arithmetic(type)) {
8579                 if (is_type_valid(type)) {
8580                         /* TODO: improve error message */
8581                         errorf(&expression->base.source_position,
8582                                 "operation needs an arithmetic type");
8583                 }
8584                 return;
8585         }
8586
8587         expression->base.type = orig_type;
8588 }
8589
8590 static void semantic_unexpr_plus(unary_expression_t *expression)
8591 {
8592         semantic_unexpr_arithmetic(expression);
8593         if (warning.traditional)
8594                 warningf(&expression->base.source_position,
8595                         "traditional C rejects the unary plus operator");
8596 }
8597
8598 static void semantic_not(unary_expression_t *expression)
8599 {
8600         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8601         semantic_condition(expression->value, "operand of !");
8602         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8603 }
8604
8605 static void semantic_unexpr_integer(unary_expression_t *expression)
8606 {
8607         type_t *const orig_type = expression->value->base.type;
8608         type_t *const type      = skip_typeref(orig_type);
8609         if (!is_type_integer(type)) {
8610                 if (is_type_valid(type)) {
8611                         errorf(&expression->base.source_position,
8612                                "operand of ~ must be of integer type");
8613                 }
8614                 return;
8615         }
8616
8617         expression->base.type = orig_type;
8618 }
8619
8620 static void semantic_dereference(unary_expression_t *expression)
8621 {
8622         type_t *const orig_type = expression->value->base.type;
8623         type_t *const type      = skip_typeref(orig_type);
8624         if (!is_type_pointer(type)) {
8625                 if (is_type_valid(type)) {
8626                         errorf(&expression->base.source_position,
8627                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8628                 }
8629                 return;
8630         }
8631
8632         type_t *result_type   = type->pointer.points_to;
8633         result_type           = automatic_type_conversion(result_type);
8634         expression->base.type = result_type;
8635 }
8636
8637 /**
8638  * Record that an address is taken (expression represents an lvalue).
8639  *
8640  * @param expression       the expression
8641  * @param may_be_register  if true, the expression might be an register
8642  */
8643 static void set_address_taken(expression_t *expression, bool may_be_register)
8644 {
8645         if (expression->kind != EXPR_REFERENCE)
8646                 return;
8647
8648         entity_t *const entity = expression->reference.entity;
8649
8650         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8651                 return;
8652
8653         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8654                         && !may_be_register) {
8655                 errorf(&expression->base.source_position,
8656                                 "address of register %s '%Y' requested",
8657                                 get_entity_kind_name(entity->kind),     entity->base.symbol);
8658         }
8659
8660         if (entity->kind == ENTITY_VARIABLE) {
8661                 entity->variable.address_taken = true;
8662         } else {
8663                 assert(entity->kind == ENTITY_PARAMETER);
8664                 entity->parameter.address_taken = true;
8665         }
8666 }
8667
8668 /**
8669  * Check the semantic of the address taken expression.
8670  */
8671 static void semantic_take_addr(unary_expression_t *expression)
8672 {
8673         expression_t *value = expression->value;
8674         value->base.type    = revert_automatic_type_conversion(value);
8675
8676         type_t *orig_type = value->base.type;
8677         type_t *type      = skip_typeref(orig_type);
8678         if (!is_type_valid(type))
8679                 return;
8680
8681         /* §6.5.3.2 */
8682         if (!is_lvalue(value)) {
8683                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8684         }
8685         if (type->kind == TYPE_BITFIELD) {
8686                 errorf(&expression->base.source_position,
8687                        "'&' not allowed on object with bitfield type '%T'",
8688                        type);
8689         }
8690
8691         set_address_taken(value, false);
8692
8693         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8694 }
8695
8696 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8697 static expression_t *parse_##unexpression_type(void)                         \
8698 {                                                                            \
8699         expression_t *unary_expression                                           \
8700                 = allocate_expression_zero(unexpression_type);                       \
8701         eat(token_type);                                                         \
8702         unary_expression->unary.value = parse_sub_expression(PREC_UNARY);        \
8703                                                                                  \
8704         sfunc(&unary_expression->unary);                                         \
8705                                                                                  \
8706         return unary_expression;                                                 \
8707 }
8708
8709 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8710                                semantic_unexpr_arithmetic)
8711 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8712                                semantic_unexpr_plus)
8713 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8714                                semantic_not)
8715 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8716                                semantic_dereference)
8717 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8718                                semantic_take_addr)
8719 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8720                                semantic_unexpr_integer)
8721 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8722                                semantic_incdec)
8723 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8724                                semantic_incdec)
8725
8726 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8727                                                sfunc)                         \
8728 static expression_t *parse_##unexpression_type(expression_t *left)            \
8729 {                                                                             \
8730         expression_t *unary_expression                                            \
8731                 = allocate_expression_zero(unexpression_type);                        \
8732         eat(token_type);                                                          \
8733         unary_expression->unary.value = left;                                     \
8734                                                                                   \
8735         sfunc(&unary_expression->unary);                                          \
8736                                                                               \
8737         return unary_expression;                                                  \
8738 }
8739
8740 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8741                                        EXPR_UNARY_POSTFIX_INCREMENT,
8742                                        semantic_incdec)
8743 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8744                                        EXPR_UNARY_POSTFIX_DECREMENT,
8745                                        semantic_incdec)
8746
8747 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8748 {
8749         /* TODO: handle complex + imaginary types */
8750
8751         type_left  = get_unqualified_type(type_left);
8752         type_right = get_unqualified_type(type_right);
8753
8754         /* §6.3.1.8 Usual arithmetic conversions */
8755         if (type_left == type_long_double || type_right == type_long_double) {
8756                 return type_long_double;
8757         } else if (type_left == type_double || type_right == type_double) {
8758                 return type_double;
8759         } else if (type_left == type_float || type_right == type_float) {
8760                 return type_float;
8761         }
8762
8763         type_left  = promote_integer(type_left);
8764         type_right = promote_integer(type_right);
8765
8766         if (type_left == type_right)
8767                 return type_left;
8768
8769         bool const signed_left  = is_type_signed(type_left);
8770         bool const signed_right = is_type_signed(type_right);
8771         int const  rank_left    = get_rank(type_left);
8772         int const  rank_right   = get_rank(type_right);
8773
8774         if (signed_left == signed_right)
8775                 return rank_left >= rank_right ? type_left : type_right;
8776
8777         int     s_rank;
8778         int     u_rank;
8779         type_t *s_type;
8780         type_t *u_type;
8781         if (signed_left) {
8782                 s_rank = rank_left;
8783                 s_type = type_left;
8784                 u_rank = rank_right;
8785                 u_type = type_right;
8786         } else {
8787                 s_rank = rank_right;
8788                 s_type = type_right;
8789                 u_rank = rank_left;
8790                 u_type = type_left;
8791         }
8792
8793         if (u_rank >= s_rank)
8794                 return u_type;
8795
8796         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8797          * easier here... */
8798         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8799                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8800                 return s_type;
8801
8802         switch (s_rank) {
8803                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8804                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8805                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8806
8807                 default: panic("invalid atomic type");
8808         }
8809 }
8810
8811 /**
8812  * Check the semantic restrictions for a binary expression.
8813  */
8814 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8815 {
8816         expression_t *const left            = expression->left;
8817         expression_t *const right           = expression->right;
8818         type_t       *const orig_type_left  = left->base.type;
8819         type_t       *const orig_type_right = right->base.type;
8820         type_t       *const type_left       = skip_typeref(orig_type_left);
8821         type_t       *const type_right      = skip_typeref(orig_type_right);
8822
8823         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8824                 /* TODO: improve error message */
8825                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8826                         errorf(&expression->base.source_position,
8827                                "operation needs arithmetic types");
8828                 }
8829                 return;
8830         }
8831
8832         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8833         expression->left      = create_implicit_cast(left, arithmetic_type);
8834         expression->right     = create_implicit_cast(right, arithmetic_type);
8835         expression->base.type = arithmetic_type;
8836 }
8837
8838 static void warn_div_by_zero(binary_expression_t const *const expression)
8839 {
8840         if (!warning.div_by_zero ||
8841             !is_type_integer(expression->base.type))
8842                 return;
8843
8844         expression_t const *const right = expression->right;
8845         /* The type of the right operand can be different for /= */
8846         if (is_type_integer(right->base.type) &&
8847             is_constant_expression(right)     &&
8848             fold_constant(right) == 0) {
8849                 warningf(&expression->base.source_position, "division by zero");
8850         }
8851 }
8852
8853 /**
8854  * Check the semantic restrictions for a div/mod expression.
8855  */
8856 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8857 {
8858         semantic_binexpr_arithmetic(expression);
8859         warn_div_by_zero(expression);
8860 }
8861
8862 static void warn_addsub_in_shift(const expression_t *const expr)
8863 {
8864         if (expr->base.parenthesized)
8865                 return;
8866
8867         char op;
8868         switch (expr->kind) {
8869                 case EXPR_BINARY_ADD: op = '+'; break;
8870                 case EXPR_BINARY_SUB: op = '-'; break;
8871                 default:              return;
8872         }
8873
8874         warningf(&expr->base.source_position,
8875                         "suggest parentheses around '%c' inside shift", op);
8876 }
8877
8878 static void semantic_shift_op(binary_expression_t *expression)
8879 {
8880         expression_t *const left            = expression->left;
8881         expression_t *const right           = expression->right;
8882         type_t       *const orig_type_left  = left->base.type;
8883         type_t       *const orig_type_right = right->base.type;
8884         type_t       *      type_left       = skip_typeref(orig_type_left);
8885         type_t       *      type_right      = skip_typeref(orig_type_right);
8886
8887         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8888                 /* TODO: improve error message */
8889                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8890                         errorf(&expression->base.source_position,
8891                                "operands of shift operation must have integer types");
8892                 }
8893                 return;
8894         }
8895
8896         if (warning.parentheses) {
8897                 warn_addsub_in_shift(left);
8898                 warn_addsub_in_shift(right);
8899         }
8900
8901         type_left  = promote_integer(type_left);
8902         type_right = promote_integer(type_right);
8903
8904         expression->left      = create_implicit_cast(left, type_left);
8905         expression->right     = create_implicit_cast(right, type_right);
8906         expression->base.type = type_left;
8907 }
8908
8909 static void semantic_add(binary_expression_t *expression)
8910 {
8911         expression_t *const left            = expression->left;
8912         expression_t *const right           = expression->right;
8913         type_t       *const orig_type_left  = left->base.type;
8914         type_t       *const orig_type_right = right->base.type;
8915         type_t       *const type_left       = skip_typeref(orig_type_left);
8916         type_t       *const type_right      = skip_typeref(orig_type_right);
8917
8918         /* §6.5.6 */
8919         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8920                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8921                 expression->left  = create_implicit_cast(left, arithmetic_type);
8922                 expression->right = create_implicit_cast(right, arithmetic_type);
8923                 expression->base.type = arithmetic_type;
8924         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8925                 check_pointer_arithmetic(&expression->base.source_position,
8926                                          type_left, orig_type_left);
8927                 expression->base.type = type_left;
8928         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8929                 check_pointer_arithmetic(&expression->base.source_position,
8930                                          type_right, orig_type_right);
8931                 expression->base.type = type_right;
8932         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8933                 errorf(&expression->base.source_position,
8934                        "invalid operands to binary + ('%T', '%T')",
8935                        orig_type_left, orig_type_right);
8936         }
8937 }
8938
8939 static void semantic_sub(binary_expression_t *expression)
8940 {
8941         expression_t            *const left            = expression->left;
8942         expression_t            *const right           = expression->right;
8943         type_t                  *const orig_type_left  = left->base.type;
8944         type_t                  *const orig_type_right = right->base.type;
8945         type_t                  *const type_left       = skip_typeref(orig_type_left);
8946         type_t                  *const type_right      = skip_typeref(orig_type_right);
8947         source_position_t const *const pos             = &expression->base.source_position;
8948
8949         /* §5.6.5 */
8950         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8951                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8952                 expression->left        = create_implicit_cast(left, arithmetic_type);
8953                 expression->right       = create_implicit_cast(right, arithmetic_type);
8954                 expression->base.type =  arithmetic_type;
8955         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8956                 check_pointer_arithmetic(&expression->base.source_position,
8957                                          type_left, orig_type_left);
8958                 expression->base.type = type_left;
8959         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8960                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8961                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8962                 if (!types_compatible(unqual_left, unqual_right)) {
8963                         errorf(pos,
8964                                "subtracting pointers to incompatible types '%T' and '%T'",
8965                                orig_type_left, orig_type_right);
8966                 } else if (!is_type_object(unqual_left)) {
8967                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8968                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8969                                        orig_type_left);
8970                         } else if (warning.other) {
8971                                 warningf(pos, "subtracting pointers to void");
8972                         }
8973                 }
8974                 expression->base.type = type_ptrdiff_t;
8975         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8976                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8977                        orig_type_left, orig_type_right);
8978         }
8979 }
8980
8981 static void warn_string_literal_address(expression_t const* expr)
8982 {
8983         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8984                 expr = expr->unary.value;
8985                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8986                         return;
8987                 expr = expr->unary.value;
8988         }
8989
8990         if (expr->kind == EXPR_STRING_LITERAL ||
8991             expr->kind == EXPR_WIDE_STRING_LITERAL) {
8992                 warningf(&expr->base.source_position,
8993                         "comparison with string literal results in unspecified behaviour");
8994         }
8995 }
8996
8997 static void warn_comparison_in_comparison(const expression_t *const expr)
8998 {
8999         if (expr->base.parenthesized)
9000                 return;
9001         switch (expr->base.kind) {
9002                 case EXPR_BINARY_LESS:
9003                 case EXPR_BINARY_GREATER:
9004                 case EXPR_BINARY_LESSEQUAL:
9005                 case EXPR_BINARY_GREATEREQUAL:
9006                 case EXPR_BINARY_NOTEQUAL:
9007                 case EXPR_BINARY_EQUAL:
9008                         warningf(&expr->base.source_position,
9009                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
9010                         break;
9011                 default:
9012                         break;
9013         }
9014 }
9015
9016 static bool maybe_negative(expression_t const *const expr)
9017 {
9018         return
9019                 !is_constant_expression(expr) ||
9020                 fold_constant(expr) < 0;
9021 }
9022
9023 /**
9024  * Check the semantics of comparison expressions.
9025  *
9026  * @param expression   The expression to check.
9027  */
9028 static void semantic_comparison(binary_expression_t *expression)
9029 {
9030         expression_t *left  = expression->left;
9031         expression_t *right = expression->right;
9032
9033         if (warning.address) {
9034                 warn_string_literal_address(left);
9035                 warn_string_literal_address(right);
9036
9037                 expression_t const* const func_left = get_reference_address(left);
9038                 if (func_left != NULL && is_null_pointer_constant(right)) {
9039                         warningf(&expression->base.source_position,
9040                                  "the address of '%Y' will never be NULL",
9041                                  func_left->reference.entity->base.symbol);
9042                 }
9043
9044                 expression_t const* const func_right = get_reference_address(right);
9045                 if (func_right != NULL && is_null_pointer_constant(right)) {
9046                         warningf(&expression->base.source_position,
9047                                  "the address of '%Y' will never be NULL",
9048                                  func_right->reference.entity->base.symbol);
9049                 }
9050         }
9051
9052         if (warning.parentheses) {
9053                 warn_comparison_in_comparison(left);
9054                 warn_comparison_in_comparison(right);
9055         }
9056
9057         type_t *orig_type_left  = left->base.type;
9058         type_t *orig_type_right = right->base.type;
9059         type_t *type_left       = skip_typeref(orig_type_left);
9060         type_t *type_right      = skip_typeref(orig_type_right);
9061
9062         /* TODO non-arithmetic types */
9063         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9064                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9065
9066                 /* test for signed vs unsigned compares */
9067                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
9068                         bool const signed_left  = is_type_signed(type_left);
9069                         bool const signed_right = is_type_signed(type_right);
9070                         if (signed_left != signed_right) {
9071                                 /* FIXME long long needs better const folding magic */
9072                                 /* TODO check whether constant value can be represented by other type */
9073                                 if ((signed_left  && maybe_negative(left)) ||
9074                                                 (signed_right && maybe_negative(right))) {
9075                                         warningf(&expression->base.source_position,
9076                                                         "comparison between signed and unsigned");
9077                                 }
9078                         }
9079                 }
9080
9081                 expression->left        = create_implicit_cast(left, arithmetic_type);
9082                 expression->right       = create_implicit_cast(right, arithmetic_type);
9083                 expression->base.type   = arithmetic_type;
9084                 if (warning.float_equal &&
9085                     (expression->base.kind == EXPR_BINARY_EQUAL ||
9086                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
9087                     is_type_float(arithmetic_type)) {
9088                         warningf(&expression->base.source_position,
9089                                  "comparing floating point with == or != is unsafe");
9090                 }
9091         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
9092                 /* TODO check compatibility */
9093         } else if (is_type_pointer(type_left)) {
9094                 expression->right = create_implicit_cast(right, type_left);
9095         } else if (is_type_pointer(type_right)) {
9096                 expression->left = create_implicit_cast(left, type_right);
9097         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9098                 type_error_incompatible("invalid operands in comparison",
9099                                         &expression->base.source_position,
9100                                         type_left, type_right);
9101         }
9102         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9103 }
9104
9105 /**
9106  * Checks if a compound type has constant fields.
9107  */
9108 static bool has_const_fields(const compound_type_t *type)
9109 {
9110         compound_t *compound = type->compound;
9111         entity_t   *entry    = compound->members.entities;
9112
9113         for (; entry != NULL; entry = entry->base.next) {
9114                 if (!is_declaration(entry))
9115                         continue;
9116
9117                 const type_t *decl_type = skip_typeref(entry->declaration.type);
9118                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
9119                         return true;
9120         }
9121
9122         return false;
9123 }
9124
9125 static bool is_valid_assignment_lhs(expression_t const* const left)
9126 {
9127         type_t *const orig_type_left = revert_automatic_type_conversion(left);
9128         type_t *const type_left      = skip_typeref(orig_type_left);
9129
9130         if (!is_lvalue(left)) {
9131                 errorf(HERE, "left hand side '%E' of assignment is not an lvalue",
9132                        left);
9133                 return false;
9134         }
9135
9136         if (left->kind == EXPR_REFERENCE
9137                         && left->reference.entity->kind == ENTITY_FUNCTION) {
9138                 errorf(HERE, "cannot assign to function '%E'", left);
9139                 return false;
9140         }
9141
9142         if (is_type_array(type_left)) {
9143                 errorf(HERE, "cannot assign to array '%E'", left);
9144                 return false;
9145         }
9146         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
9147                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
9148                        orig_type_left);
9149                 return false;
9150         }
9151         if (is_type_incomplete(type_left)) {
9152                 errorf(HERE, "left-hand side '%E' of assignment has incomplete type '%T'",
9153                        left, orig_type_left);
9154                 return false;
9155         }
9156         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
9157                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
9158                        left, orig_type_left);
9159                 return false;
9160         }
9161
9162         return true;
9163 }
9164
9165 static void semantic_arithmetic_assign(binary_expression_t *expression)
9166 {
9167         expression_t *left            = expression->left;
9168         expression_t *right           = expression->right;
9169         type_t       *orig_type_left  = left->base.type;
9170         type_t       *orig_type_right = right->base.type;
9171
9172         if (!is_valid_assignment_lhs(left))
9173                 return;
9174
9175         type_t *type_left  = skip_typeref(orig_type_left);
9176         type_t *type_right = skip_typeref(orig_type_right);
9177
9178         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
9179                 /* TODO: improve error message */
9180                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
9181                         errorf(&expression->base.source_position,
9182                                "operation needs arithmetic types");
9183                 }
9184                 return;
9185         }
9186
9187         /* combined instructions are tricky. We can't create an implicit cast on
9188          * the left side, because we need the uncasted form for the store.
9189          * The ast2firm pass has to know that left_type must be right_type
9190          * for the arithmetic operation and create a cast by itself */
9191         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
9192         expression->right       = create_implicit_cast(right, arithmetic_type);
9193         expression->base.type   = type_left;
9194 }
9195
9196 static void semantic_divmod_assign(binary_expression_t *expression)
9197 {
9198         semantic_arithmetic_assign(expression);
9199         warn_div_by_zero(expression);
9200 }
9201
9202 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
9203 {
9204         expression_t *const left            = expression->left;
9205         expression_t *const right           = expression->right;
9206         type_t       *const orig_type_left  = left->base.type;
9207         type_t       *const orig_type_right = right->base.type;
9208         type_t       *const type_left       = skip_typeref(orig_type_left);
9209         type_t       *const type_right      = skip_typeref(orig_type_right);
9210
9211         if (!is_valid_assignment_lhs(left))
9212                 return;
9213
9214         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
9215                 /* combined instructions are tricky. We can't create an implicit cast on
9216                  * the left side, because we need the uncasted form for the store.
9217                  * The ast2firm pass has to know that left_type must be right_type
9218                  * for the arithmetic operation and create a cast by itself */
9219                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
9220                 expression->right     = create_implicit_cast(right, arithmetic_type);
9221                 expression->base.type = type_left;
9222         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
9223                 check_pointer_arithmetic(&expression->base.source_position,
9224                                          type_left, orig_type_left);
9225                 expression->base.type = type_left;
9226         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
9227                 errorf(&expression->base.source_position,
9228                        "incompatible types '%T' and '%T' in assignment",
9229                        orig_type_left, orig_type_right);
9230         }
9231 }
9232
9233 static void warn_logical_and_within_or(const expression_t *const expr)
9234 {
9235         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
9236                 return;
9237         if (expr->base.parenthesized)
9238                 return;
9239         warningf(&expr->base.source_position,
9240                         "suggest parentheses around && within ||");
9241 }
9242
9243 /**
9244  * Check the semantic restrictions of a logical expression.
9245  */
9246 static void semantic_logical_op(binary_expression_t *expression)
9247 {
9248         /* §6.5.13:2  Each of the operands shall have scalar type.
9249          * §6.5.14:2  Each of the operands shall have scalar type. */
9250         semantic_condition(expression->left,   "left operand of logical operator");
9251         semantic_condition(expression->right, "right operand of logical operator");
9252         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
9253                         warning.parentheses) {
9254                 warn_logical_and_within_or(expression->left);
9255                 warn_logical_and_within_or(expression->right);
9256         }
9257         expression->base.type = c_mode & _CXX ? type_bool : type_int;
9258 }
9259
9260 /**
9261  * Check the semantic restrictions of a binary assign expression.
9262  */
9263 static void semantic_binexpr_assign(binary_expression_t *expression)
9264 {
9265         expression_t *left           = expression->left;
9266         type_t       *orig_type_left = left->base.type;
9267
9268         if (!is_valid_assignment_lhs(left))
9269                 return;
9270
9271         assign_error_t error = semantic_assign(orig_type_left, expression->right);
9272         report_assign_error(error, orig_type_left, expression->right,
9273                         "assignment", &left->base.source_position);
9274         expression->right = create_implicit_cast(expression->right, orig_type_left);
9275         expression->base.type = orig_type_left;
9276 }
9277
9278 /**
9279  * Determine if the outermost operation (or parts thereof) of the given
9280  * expression has no effect in order to generate a warning about this fact.
9281  * Therefore in some cases this only examines some of the operands of the
9282  * expression (see comments in the function and examples below).
9283  * Examples:
9284  *   f() + 23;    // warning, because + has no effect
9285  *   x || f();    // no warning, because x controls execution of f()
9286  *   x ? y : f(); // warning, because y has no effect
9287  *   (void)x;     // no warning to be able to suppress the warning
9288  * This function can NOT be used for an "expression has definitely no effect"-
9289  * analysis. */
9290 static bool expression_has_effect(const expression_t *const expr)
9291 {
9292         switch (expr->kind) {
9293                 case EXPR_UNKNOWN:                    break;
9294                 case EXPR_INVALID:                    return true; /* do NOT warn */
9295                 case EXPR_REFERENCE:                  return false;
9296                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
9297                 /* suppress the warning for microsoft __noop operations */
9298                 case EXPR_CONST:                      return expr->conste.is_ms_noop;
9299                 case EXPR_CHARACTER_CONSTANT:         return false;
9300                 case EXPR_WIDE_CHARACTER_CONSTANT:    return false;
9301                 case EXPR_STRING_LITERAL:             return false;
9302                 case EXPR_WIDE_STRING_LITERAL:        return false;
9303                 case EXPR_LABEL_ADDRESS:              return false;
9304
9305                 case EXPR_CALL: {
9306                         const call_expression_t *const call = &expr->call;
9307                         if (call->function->kind != EXPR_REFERENCE)
9308                                 return true;
9309
9310                         switch (call->function->reference.entity->function.btk) {
9311                                 /* FIXME: which builtins have no effect? */
9312                                 default:                      return true;
9313                         }
9314                 }
9315
9316                 /* Generate the warning if either the left or right hand side of a
9317                  * conditional expression has no effect */
9318                 case EXPR_CONDITIONAL: {
9319                         conditional_expression_t const *const cond = &expr->conditional;
9320                         expression_t             const *const t    = cond->true_expression;
9321                         return
9322                                 (t == NULL || expression_has_effect(t)) &&
9323                                 expression_has_effect(cond->false_expression);
9324                 }
9325
9326                 case EXPR_SELECT:                     return false;
9327                 case EXPR_ARRAY_ACCESS:               return false;
9328                 case EXPR_SIZEOF:                     return false;
9329                 case EXPR_CLASSIFY_TYPE:              return false;
9330                 case EXPR_ALIGNOF:                    return false;
9331
9332                 case EXPR_FUNCNAME:                   return false;
9333                 case EXPR_BUILTIN_CONSTANT_P:         return false;
9334                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
9335                 case EXPR_OFFSETOF:                   return false;
9336                 case EXPR_VA_START:                   return true;
9337                 case EXPR_VA_ARG:                     return true;
9338                 case EXPR_STATEMENT:                  return true; // TODO
9339                 case EXPR_COMPOUND_LITERAL:           return false;
9340
9341                 case EXPR_UNARY_NEGATE:               return false;
9342                 case EXPR_UNARY_PLUS:                 return false;
9343                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
9344                 case EXPR_UNARY_NOT:                  return false;
9345                 case EXPR_UNARY_DEREFERENCE:          return false;
9346                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
9347                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
9348                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
9349                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
9350                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
9351
9352                 /* Treat void casts as if they have an effect in order to being able to
9353                  * suppress the warning */
9354                 case EXPR_UNARY_CAST: {
9355                         type_t *const type = skip_typeref(expr->base.type);
9356                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
9357                 }
9358
9359                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
9360                 case EXPR_UNARY_ASSUME:               return true;
9361                 case EXPR_UNARY_DELETE:               return true;
9362                 case EXPR_UNARY_DELETE_ARRAY:         return true;
9363                 case EXPR_UNARY_THROW:                return true;
9364
9365                 case EXPR_BINARY_ADD:                 return false;
9366                 case EXPR_BINARY_SUB:                 return false;
9367                 case EXPR_BINARY_MUL:                 return false;
9368                 case EXPR_BINARY_DIV:                 return false;
9369                 case EXPR_BINARY_MOD:                 return false;
9370                 case EXPR_BINARY_EQUAL:               return false;
9371                 case EXPR_BINARY_NOTEQUAL:            return false;
9372                 case EXPR_BINARY_LESS:                return false;
9373                 case EXPR_BINARY_LESSEQUAL:           return false;
9374                 case EXPR_BINARY_GREATER:             return false;
9375                 case EXPR_BINARY_GREATEREQUAL:        return false;
9376                 case EXPR_BINARY_BITWISE_AND:         return false;
9377                 case EXPR_BINARY_BITWISE_OR:          return false;
9378                 case EXPR_BINARY_BITWISE_XOR:         return false;
9379                 case EXPR_BINARY_SHIFTLEFT:           return false;
9380                 case EXPR_BINARY_SHIFTRIGHT:          return false;
9381                 case EXPR_BINARY_ASSIGN:              return true;
9382                 case EXPR_BINARY_MUL_ASSIGN:          return true;
9383                 case EXPR_BINARY_DIV_ASSIGN:          return true;
9384                 case EXPR_BINARY_MOD_ASSIGN:          return true;
9385                 case EXPR_BINARY_ADD_ASSIGN:          return true;
9386                 case EXPR_BINARY_SUB_ASSIGN:          return true;
9387                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
9388                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
9389                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
9390                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
9391                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
9392
9393                 /* Only examine the right hand side of && and ||, because the left hand
9394                  * side already has the effect of controlling the execution of the right
9395                  * hand side */
9396                 case EXPR_BINARY_LOGICAL_AND:
9397                 case EXPR_BINARY_LOGICAL_OR:
9398                 /* Only examine the right hand side of a comma expression, because the left
9399                  * hand side has a separate warning */
9400                 case EXPR_BINARY_COMMA:
9401                         return expression_has_effect(expr->binary.right);
9402
9403                 case EXPR_BINARY_ISGREATER:           return false;
9404                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
9405                 case EXPR_BINARY_ISLESS:              return false;
9406                 case EXPR_BINARY_ISLESSEQUAL:         return false;
9407                 case EXPR_BINARY_ISLESSGREATER:       return false;
9408                 case EXPR_BINARY_ISUNORDERED:         return false;
9409         }
9410
9411         internal_errorf(HERE, "unexpected expression");
9412 }
9413
9414 static void semantic_comma(binary_expression_t *expression)
9415 {
9416         if (warning.unused_value) {
9417                 const expression_t *const left = expression->left;
9418                 if (!expression_has_effect(left)) {
9419                         warningf(&left->base.source_position,
9420                                  "left-hand operand of comma expression has no effect");
9421                 }
9422         }
9423         expression->base.type = expression->right->base.type;
9424 }
9425
9426 /**
9427  * @param prec_r precedence of the right operand
9428  */
9429 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
9430 static expression_t *parse_##binexpression_type(expression_t *left)          \
9431 {                                                                            \
9432         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
9433         binexpr->binary.left  = left;                                            \
9434         eat(token_type);                                                         \
9435                                                                              \
9436         expression_t *right = parse_sub_expression(prec_r);                      \
9437                                                                              \
9438         binexpr->binary.right = right;                                           \
9439         sfunc(&binexpr->binary);                                                 \
9440                                                                              \
9441         return binexpr;                                                          \
9442 }
9443
9444 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
9445 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
9446 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
9447 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
9448 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
9449 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
9450 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
9451 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
9452 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
9453 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
9454 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
9455 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
9456 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
9457 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_arithmetic)
9458 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_arithmetic)
9459 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_arithmetic)
9460 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9461 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9462 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9463 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9464 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9465 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9466 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9467 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9468 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9469 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9470 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9471 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9472 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9473 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9474
9475
9476 static expression_t *parse_sub_expression(precedence_t precedence)
9477 {
9478         if (token.type < 0) {
9479                 return expected_expression_error();
9480         }
9481
9482         expression_parser_function_t *parser
9483                 = &expression_parsers[token.type];
9484         source_position_t             source_position = token.source_position;
9485         expression_t                 *left;
9486
9487         if (parser->parser != NULL) {
9488                 left = parser->parser();
9489         } else {
9490                 left = parse_primary_expression();
9491         }
9492         assert(left != NULL);
9493         left->base.source_position = source_position;
9494
9495         while (true) {
9496                 if (token.type < 0) {
9497                         return expected_expression_error();
9498                 }
9499
9500                 parser = &expression_parsers[token.type];
9501                 if (parser->infix_parser == NULL)
9502                         break;
9503                 if (parser->infix_precedence < precedence)
9504                         break;
9505
9506                 left = parser->infix_parser(left);
9507
9508                 assert(left != NULL);
9509                 assert(left->kind != EXPR_UNKNOWN);
9510                 left->base.source_position = source_position;
9511         }
9512
9513         return left;
9514 }
9515
9516 /**
9517  * Parse an expression.
9518  */
9519 static expression_t *parse_expression(void)
9520 {
9521         return parse_sub_expression(PREC_EXPRESSION);
9522 }
9523
9524 /**
9525  * Register a parser for a prefix-like operator.
9526  *
9527  * @param parser      the parser function
9528  * @param token_type  the token type of the prefix token
9529  */
9530 static void register_expression_parser(parse_expression_function parser,
9531                                        int token_type)
9532 {
9533         expression_parser_function_t *entry = &expression_parsers[token_type];
9534
9535         if (entry->parser != NULL) {
9536                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9537                 panic("trying to register multiple expression parsers for a token");
9538         }
9539         entry->parser = parser;
9540 }
9541
9542 /**
9543  * Register a parser for an infix operator with given precedence.
9544  *
9545  * @param parser      the parser function
9546  * @param token_type  the token type of the infix operator
9547  * @param precedence  the precedence of the operator
9548  */
9549 static void register_infix_parser(parse_expression_infix_function parser,
9550                 int token_type, precedence_t precedence)
9551 {
9552         expression_parser_function_t *entry = &expression_parsers[token_type];
9553
9554         if (entry->infix_parser != NULL) {
9555                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9556                 panic("trying to register multiple infix expression parsers for a "
9557                       "token");
9558         }
9559         entry->infix_parser     = parser;
9560         entry->infix_precedence = precedence;
9561 }
9562
9563 /**
9564  * Initialize the expression parsers.
9565  */
9566 static void init_expression_parsers(void)
9567 {
9568         memset(&expression_parsers, 0, sizeof(expression_parsers));
9569
9570         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9571         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9572         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9573         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9574         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9575         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9576         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9577         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9578         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9579         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9580         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9581         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9582         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9583         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9584         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9585         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9586         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9587         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9588         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9589         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9590         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9591         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9592         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9593         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9594         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9595         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9596         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9597         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9598         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9599         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9600         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9601         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9602         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9603         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9604         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9605         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9606         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9607
9608         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9609         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9610         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9611         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9612         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9613         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9614         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9615         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9616         register_expression_parser(parse_sizeof,                      T_sizeof);
9617         register_expression_parser(parse_alignof,                     T___alignof__);
9618         register_expression_parser(parse_extension,                   T___extension__);
9619         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9620         register_expression_parser(parse_delete,                      T_delete);
9621         register_expression_parser(parse_throw,                       T_throw);
9622 }
9623
9624 /**
9625  * Parse a asm statement arguments specification.
9626  */
9627 static asm_argument_t *parse_asm_arguments(bool is_out)
9628 {
9629         asm_argument_t  *result = NULL;
9630         asm_argument_t **anchor = &result;
9631
9632         while (token.type == T_STRING_LITERAL || token.type == '[') {
9633                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9634                 memset(argument, 0, sizeof(argument[0]));
9635
9636                 if (token.type == '[') {
9637                         eat('[');
9638                         if (token.type != T_IDENTIFIER) {
9639                                 parse_error_expected("while parsing asm argument",
9640                                                      T_IDENTIFIER, NULL);
9641                                 return NULL;
9642                         }
9643                         argument->symbol = token.v.symbol;
9644
9645                         expect(']', end_error);
9646                 }
9647
9648                 argument->constraints = parse_string_literals();
9649                 expect('(', end_error);
9650                 add_anchor_token(')');
9651                 expression_t *expression = parse_expression();
9652                 rem_anchor_token(')');
9653                 if (is_out) {
9654                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9655                          * change size or type representation (e.g. int -> long is ok, but
9656                          * int -> float is not) */
9657                         if (expression->kind == EXPR_UNARY_CAST) {
9658                                 type_t      *const type = expression->base.type;
9659                                 type_kind_t  const kind = type->kind;
9660                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9661                                         unsigned flags;
9662                                         unsigned size;
9663                                         if (kind == TYPE_ATOMIC) {
9664                                                 atomic_type_kind_t const akind = type->atomic.akind;
9665                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9666                                                 size  = get_atomic_type_size(akind);
9667                                         } else {
9668                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9669                                                 size  = get_atomic_type_size(get_intptr_kind());
9670                                         }
9671
9672                                         do {
9673                                                 expression_t *const value      = expression->unary.value;
9674                                                 type_t       *const value_type = value->base.type;
9675                                                 type_kind_t   const value_kind = value_type->kind;
9676
9677                                                 unsigned value_flags;
9678                                                 unsigned value_size;
9679                                                 if (value_kind == TYPE_ATOMIC) {
9680                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9681                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9682                                                         value_size  = get_atomic_type_size(value_akind);
9683                                                 } else if (value_kind == TYPE_POINTER) {
9684                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9685                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9686                                                 } else {
9687                                                         break;
9688                                                 }
9689
9690                                                 if (value_flags != flags || value_size != size)
9691                                                         break;
9692
9693                                                 expression = value;
9694                                         } while (expression->kind == EXPR_UNARY_CAST);
9695                                 }
9696                         }
9697
9698                         if (!is_lvalue(expression)) {
9699                                 errorf(&expression->base.source_position,
9700                                        "asm output argument is not an lvalue");
9701                         }
9702
9703                         if (argument->constraints.begin[0] == '+')
9704                                 mark_vars_read(expression, NULL);
9705                 } else {
9706                         mark_vars_read(expression, NULL);
9707                 }
9708                 argument->expression = expression;
9709                 expect(')', end_error);
9710
9711                 set_address_taken(expression, true);
9712
9713                 *anchor = argument;
9714                 anchor  = &argument->next;
9715
9716                 if (token.type != ',')
9717                         break;
9718                 eat(',');
9719         }
9720
9721         return result;
9722 end_error:
9723         return NULL;
9724 }
9725
9726 /**
9727  * Parse a asm statement clobber specification.
9728  */
9729 static asm_clobber_t *parse_asm_clobbers(void)
9730 {
9731         asm_clobber_t *result = NULL;
9732         asm_clobber_t *last   = NULL;
9733
9734         while (token.type == T_STRING_LITERAL) {
9735                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9736                 clobber->clobber       = parse_string_literals();
9737
9738                 if (last != NULL) {
9739                         last->next = clobber;
9740                 } else {
9741                         result = clobber;
9742                 }
9743                 last = clobber;
9744
9745                 if (token.type != ',')
9746                         break;
9747                 eat(',');
9748         }
9749
9750         return result;
9751 }
9752
9753 /**
9754  * Parse an asm statement.
9755  */
9756 static statement_t *parse_asm_statement(void)
9757 {
9758         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9759         asm_statement_t *asm_statement = &statement->asms;
9760
9761         eat(T_asm);
9762
9763         if (token.type == T_volatile) {
9764                 next_token();
9765                 asm_statement->is_volatile = true;
9766         }
9767
9768         expect('(', end_error);
9769         add_anchor_token(')');
9770         add_anchor_token(':');
9771         asm_statement->asm_text = parse_string_literals();
9772
9773         if (token.type != ':') {
9774                 rem_anchor_token(':');
9775                 goto end_of_asm;
9776         }
9777         eat(':');
9778
9779         asm_statement->outputs = parse_asm_arguments(true);
9780         if (token.type != ':') {
9781                 rem_anchor_token(':');
9782                 goto end_of_asm;
9783         }
9784         eat(':');
9785
9786         asm_statement->inputs = parse_asm_arguments(false);
9787         if (token.type != ':') {
9788                 rem_anchor_token(':');
9789                 goto end_of_asm;
9790         }
9791         rem_anchor_token(':');
9792         eat(':');
9793
9794         asm_statement->clobbers = parse_asm_clobbers();
9795
9796 end_of_asm:
9797         rem_anchor_token(')');
9798         expect(')', end_error);
9799         expect(';', end_error);
9800
9801         if (asm_statement->outputs == NULL) {
9802                 /* GCC: An 'asm' instruction without any output operands will be treated
9803                  * identically to a volatile 'asm' instruction. */
9804                 asm_statement->is_volatile = true;
9805         }
9806
9807         return statement;
9808 end_error:
9809         return create_invalid_statement();
9810 }
9811
9812 /**
9813  * Parse a case statement.
9814  */
9815 static statement_t *parse_case_statement(void)
9816 {
9817         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9818         source_position_t *const pos       = &statement->base.source_position;
9819
9820         eat(T_case);
9821
9822         expression_t *const expression   = parse_expression();
9823         statement->case_label.expression = expression;
9824         if (!is_constant_expression(expression)) {
9825                 /* This check does not prevent the error message in all cases of an
9826                  * prior error while parsing the expression.  At least it catches the
9827                  * common case of a mistyped enum entry. */
9828                 if (is_type_valid(skip_typeref(expression->base.type))) {
9829                         errorf(pos, "case label does not reduce to an integer constant");
9830                 }
9831                 statement->case_label.is_bad = true;
9832         } else {
9833                 long const val = fold_constant(expression);
9834                 statement->case_label.first_case = val;
9835                 statement->case_label.last_case  = val;
9836         }
9837
9838         if (GNU_MODE) {
9839                 if (token.type == T_DOTDOTDOT) {
9840                         next_token();
9841                         expression_t *const end_range   = parse_expression();
9842                         statement->case_label.end_range = end_range;
9843                         if (!is_constant_expression(end_range)) {
9844                                 /* This check does not prevent the error message in all cases of an
9845                                  * prior error while parsing the expression.  At least it catches the
9846                                  * common case of a mistyped enum entry. */
9847                                 if (is_type_valid(skip_typeref(end_range->base.type))) {
9848                                         errorf(pos, "case range does not reduce to an integer constant");
9849                                 }
9850                                 statement->case_label.is_bad = true;
9851                         } else {
9852                                 long const val = fold_constant(end_range);
9853                                 statement->case_label.last_case = val;
9854
9855                                 if (warning.other && val < statement->case_label.first_case) {
9856                                         statement->case_label.is_empty_range = true;
9857                                         warningf(pos, "empty range specified");
9858                                 }
9859                         }
9860                 }
9861         }
9862
9863         PUSH_PARENT(statement);
9864
9865         expect(':', end_error);
9866 end_error:
9867
9868         if (current_switch != NULL) {
9869                 if (! statement->case_label.is_bad) {
9870                         /* Check for duplicate case values */
9871                         case_label_statement_t *c = &statement->case_label;
9872                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9873                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9874                                         continue;
9875
9876                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9877                                         continue;
9878
9879                                 errorf(pos, "duplicate case value (previously used %P)",
9880                                        &l->base.source_position);
9881                                 break;
9882                         }
9883                 }
9884                 /* link all cases into the switch statement */
9885                 if (current_switch->last_case == NULL) {
9886                         current_switch->first_case      = &statement->case_label;
9887                 } else {
9888                         current_switch->last_case->next = &statement->case_label;
9889                 }
9890                 current_switch->last_case = &statement->case_label;
9891         } else {
9892                 errorf(pos, "case label not within a switch statement");
9893         }
9894
9895         statement_t *const inner_stmt = parse_statement();
9896         statement->case_label.statement = inner_stmt;
9897         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9898                 errorf(&inner_stmt->base.source_position, "declaration after case label");
9899         }
9900
9901         POP_PARENT;
9902         return statement;
9903 }
9904
9905 /**
9906  * Parse a default statement.
9907  */
9908 static statement_t *parse_default_statement(void)
9909 {
9910         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9911
9912         eat(T_default);
9913
9914         PUSH_PARENT(statement);
9915
9916         expect(':', end_error);
9917         if (current_switch != NULL) {
9918                 const case_label_statement_t *def_label = current_switch->default_label;
9919                 if (def_label != NULL) {
9920                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9921                                &def_label->base.source_position);
9922                 } else {
9923                         current_switch->default_label = &statement->case_label;
9924
9925                         /* link all cases into the switch statement */
9926                         if (current_switch->last_case == NULL) {
9927                                 current_switch->first_case      = &statement->case_label;
9928                         } else {
9929                                 current_switch->last_case->next = &statement->case_label;
9930                         }
9931                         current_switch->last_case = &statement->case_label;
9932                 }
9933         } else {
9934                 errorf(&statement->base.source_position,
9935                         "'default' label not within a switch statement");
9936         }
9937
9938         statement_t *const inner_stmt = parse_statement();
9939         statement->case_label.statement = inner_stmt;
9940         if (inner_stmt->kind == STATEMENT_DECLARATION) {
9941                 errorf(&inner_stmt->base.source_position, "declaration after default label");
9942         }
9943
9944         POP_PARENT;
9945         return statement;
9946 end_error:
9947         POP_PARENT;
9948         return create_invalid_statement();
9949 }
9950
9951 /**
9952  * Parse a label statement.
9953  */
9954 static statement_t *parse_label_statement(void)
9955 {
9956         assert(token.type == T_IDENTIFIER);
9957         symbol_t *symbol = token.v.symbol;
9958         label_t  *label  = get_label(symbol);
9959
9960         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9961         statement->label.label       = label;
9962
9963         next_token();
9964
9965         PUSH_PARENT(statement);
9966
9967         /* if statement is already set then the label is defined twice,
9968          * otherwise it was just mentioned in a goto/local label declaration so far
9969          */
9970         if (label->statement != NULL) {
9971                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9972                        symbol, &label->base.source_position);
9973         } else {
9974                 label->base.source_position = token.source_position;
9975                 label->statement            = statement;
9976         }
9977
9978         eat(':');
9979
9980         if (token.type == '}') {
9981                 /* TODO only warn? */
9982                 if (warning.other && false) {
9983                         warningf(HERE, "label at end of compound statement");
9984                         statement->label.statement = create_empty_statement();
9985                 } else {
9986                         errorf(HERE, "label at end of compound statement");
9987                         statement->label.statement = create_invalid_statement();
9988                 }
9989         } else if (token.type == ';') {
9990                 /* Eat an empty statement here, to avoid the warning about an empty
9991                  * statement after a label.  label:; is commonly used to have a label
9992                  * before a closing brace. */
9993                 statement->label.statement = create_empty_statement();
9994                 next_token();
9995         } else {
9996                 statement_t *const inner_stmt = parse_statement();
9997                 statement->label.statement = inner_stmt;
9998                 if (inner_stmt->kind == STATEMENT_DECLARATION) {
9999                         errorf(&inner_stmt->base.source_position, "declaration after label");
10000                 }
10001         }
10002
10003         /* remember the labels in a list for later checking */
10004         *label_anchor = &statement->label;
10005         label_anchor  = &statement->label.next;
10006
10007         POP_PARENT;
10008         return statement;
10009 }
10010
10011 /**
10012  * Parse an if statement.
10013  */
10014 static statement_t *parse_if(void)
10015 {
10016         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
10017
10018         eat(T_if);
10019
10020         PUSH_PARENT(statement);
10021
10022         add_anchor_token('{');
10023
10024         expect('(', end_error);
10025         add_anchor_token(')');
10026         expression_t *const expr = parse_expression();
10027         statement->ifs.condition = expr;
10028         /* §6.8.4.1:1  The controlling expression of an if statement shall have
10029          *             scalar type. */
10030         semantic_condition(expr, "condition of 'if'-statment");
10031         mark_vars_read(expr, NULL);
10032         rem_anchor_token(')');
10033         expect(')', end_error);
10034
10035 end_error:
10036         rem_anchor_token('{');
10037
10038         add_anchor_token(T_else);
10039         statement_t *const true_stmt = parse_statement();
10040         statement->ifs.true_statement = true_stmt;
10041         rem_anchor_token(T_else);
10042
10043         if (token.type == T_else) {
10044                 next_token();
10045                 statement->ifs.false_statement = parse_statement();
10046         } else if (warning.parentheses &&
10047                         true_stmt->kind == STATEMENT_IF &&
10048                         true_stmt->ifs.false_statement != NULL) {
10049                 warningf(&true_stmt->base.source_position,
10050                                 "suggest explicit braces to avoid ambiguous 'else'");
10051         }
10052
10053         POP_PARENT;
10054         return statement;
10055 }
10056
10057 /**
10058  * Check that all enums are handled in a switch.
10059  *
10060  * @param statement  the switch statement to check
10061  */
10062 static void check_enum_cases(const switch_statement_t *statement)
10063 {
10064         const type_t *type = skip_typeref(statement->expression->base.type);
10065         if (! is_type_enum(type))
10066                 return;
10067         const enum_type_t *enumt = &type->enumt;
10068
10069         /* if we have a default, no warnings */
10070         if (statement->default_label != NULL)
10071                 return;
10072
10073         /* FIXME: calculation of value should be done while parsing */
10074         /* TODO: quadratic algorithm here. Change to an n log n one */
10075         long            last_value = -1;
10076         const entity_t *entry      = enumt->enume->base.next;
10077         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
10078              entry = entry->base.next) {
10079                 const expression_t *expression = entry->enum_value.value;
10080                 long                value      = expression != NULL ? fold_constant(expression) : last_value + 1;
10081                 bool                found      = false;
10082                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
10083                         if (l->expression == NULL)
10084                                 continue;
10085                         if (l->first_case <= value && value <= l->last_case) {
10086                                 found = true;
10087                                 break;
10088                         }
10089                 }
10090                 if (! found) {
10091                         warningf(&statement->base.source_position,
10092                                  "enumeration value '%Y' not handled in switch",
10093                                  entry->base.symbol);
10094                 }
10095                 last_value = value;
10096         }
10097 }
10098
10099 /**
10100  * Parse a switch statement.
10101  */
10102 static statement_t *parse_switch(void)
10103 {
10104         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
10105
10106         eat(T_switch);
10107
10108         PUSH_PARENT(statement);
10109
10110         expect('(', end_error);
10111         add_anchor_token(')');
10112         expression_t *const expr = parse_expression();
10113         mark_vars_read(expr, NULL);
10114         type_t       *      type = skip_typeref(expr->base.type);
10115         if (is_type_integer(type)) {
10116                 type = promote_integer(type);
10117                 if (warning.traditional) {
10118                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
10119                                 warningf(&expr->base.source_position,
10120                                         "'%T' switch expression not converted to '%T' in ISO C",
10121                                         type, type_int);
10122                         }
10123                 }
10124         } else if (is_type_valid(type)) {
10125                 errorf(&expr->base.source_position,
10126                        "switch quantity is not an integer, but '%T'", type);
10127                 type = type_error_type;
10128         }
10129         statement->switchs.expression = create_implicit_cast(expr, type);
10130         expect(')', end_error);
10131         rem_anchor_token(')');
10132
10133         switch_statement_t *rem = current_switch;
10134         current_switch          = &statement->switchs;
10135         statement->switchs.body = parse_statement();
10136         current_switch          = rem;
10137
10138         if (warning.switch_default &&
10139             statement->switchs.default_label == NULL) {
10140                 warningf(&statement->base.source_position, "switch has no default case");
10141         }
10142         if (warning.switch_enum)
10143                 check_enum_cases(&statement->switchs);
10144
10145         POP_PARENT;
10146         return statement;
10147 end_error:
10148         POP_PARENT;
10149         return create_invalid_statement();
10150 }
10151
10152 static statement_t *parse_loop_body(statement_t *const loop)
10153 {
10154         statement_t *const rem = current_loop;
10155         current_loop = loop;
10156
10157         statement_t *const body = parse_statement();
10158
10159         current_loop = rem;
10160         return body;
10161 }
10162
10163 /**
10164  * Parse a while statement.
10165  */
10166 static statement_t *parse_while(void)
10167 {
10168         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
10169
10170         eat(T_while);
10171
10172         PUSH_PARENT(statement);
10173
10174         expect('(', end_error);
10175         add_anchor_token(')');
10176         expression_t *const cond = parse_expression();
10177         statement->whiles.condition = cond;
10178         /* §6.8.5:2    The controlling expression of an iteration statement shall
10179          *             have scalar type. */
10180         semantic_condition(cond, "condition of 'while'-statement");
10181         mark_vars_read(cond, NULL);
10182         rem_anchor_token(')');
10183         expect(')', end_error);
10184
10185         statement->whiles.body = parse_loop_body(statement);
10186
10187         POP_PARENT;
10188         return statement;
10189 end_error:
10190         POP_PARENT;
10191         return create_invalid_statement();
10192 }
10193
10194 /**
10195  * Parse a do statement.
10196  */
10197 static statement_t *parse_do(void)
10198 {
10199         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
10200
10201         eat(T_do);
10202
10203         PUSH_PARENT(statement);
10204
10205         add_anchor_token(T_while);
10206         statement->do_while.body = parse_loop_body(statement);
10207         rem_anchor_token(T_while);
10208
10209         expect(T_while, end_error);
10210         expect('(', end_error);
10211         add_anchor_token(')');
10212         expression_t *const cond = parse_expression();
10213         statement->do_while.condition = cond;
10214         /* §6.8.5:2    The controlling expression of an iteration statement shall
10215          *             have scalar type. */
10216         semantic_condition(cond, "condition of 'do-while'-statement");
10217         mark_vars_read(cond, NULL);
10218         rem_anchor_token(')');
10219         expect(')', end_error);
10220         expect(';', end_error);
10221
10222         POP_PARENT;
10223         return statement;
10224 end_error:
10225         POP_PARENT;
10226         return create_invalid_statement();
10227 }
10228
10229 /**
10230  * Parse a for statement.
10231  */
10232 static statement_t *parse_for(void)
10233 {
10234         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
10235
10236         eat(T_for);
10237
10238         expect('(', end_error1);
10239         add_anchor_token(')');
10240
10241         PUSH_PARENT(statement);
10242
10243         size_t const  top       = environment_top();
10244         scope_t      *old_scope = scope_push(&statement->fors.scope);
10245
10246         if (token.type == ';') {
10247                 next_token();
10248         } else if (is_declaration_specifier(&token, false)) {
10249                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10250         } else {
10251                 add_anchor_token(';');
10252                 expression_t *const init = parse_expression();
10253                 statement->fors.initialisation = init;
10254                 mark_vars_read(init, ENT_ANY);
10255                 if (warning.unused_value && !expression_has_effect(init)) {
10256                         warningf(&init->base.source_position,
10257                                         "initialisation of 'for'-statement has no effect");
10258                 }
10259                 rem_anchor_token(';');
10260                 expect(';', end_error2);
10261         }
10262
10263         if (token.type != ';') {
10264                 add_anchor_token(';');
10265                 expression_t *const cond = parse_expression();
10266                 statement->fors.condition = cond;
10267                 /* §6.8.5:2    The controlling expression of an iteration statement
10268                  *             shall have scalar type. */
10269                 semantic_condition(cond, "condition of 'for'-statement");
10270                 mark_vars_read(cond, NULL);
10271                 rem_anchor_token(';');
10272         }
10273         expect(';', end_error2);
10274         if (token.type != ')') {
10275                 expression_t *const step = parse_expression();
10276                 statement->fors.step = step;
10277                 mark_vars_read(step, ENT_ANY);
10278                 if (warning.unused_value && !expression_has_effect(step)) {
10279                         warningf(&step->base.source_position,
10280                                  "step of 'for'-statement has no effect");
10281                 }
10282         }
10283         expect(')', end_error2);
10284         rem_anchor_token(')');
10285         statement->fors.body = parse_loop_body(statement);
10286
10287         assert(current_scope == &statement->fors.scope);
10288         scope_pop(old_scope);
10289         environment_pop_to(top);
10290
10291         POP_PARENT;
10292         return statement;
10293
10294 end_error2:
10295         POP_PARENT;
10296         rem_anchor_token(')');
10297         assert(current_scope == &statement->fors.scope);
10298         scope_pop(old_scope);
10299         environment_pop_to(top);
10300         /* fallthrough */
10301
10302 end_error1:
10303         return create_invalid_statement();
10304 }
10305
10306 /**
10307  * Parse a goto statement.
10308  */
10309 static statement_t *parse_goto(void)
10310 {
10311         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
10312         eat(T_goto);
10313
10314         if (GNU_MODE && token.type == '*') {
10315                 next_token();
10316                 expression_t *expression = parse_expression();
10317                 mark_vars_read(expression, NULL);
10318
10319                 /* Argh: although documentation says the expression must be of type void*,
10320                  * gcc accepts anything that can be casted into void* without error */
10321                 type_t *type = expression->base.type;
10322
10323                 if (type != type_error_type) {
10324                         if (!is_type_pointer(type) && !is_type_integer(type)) {
10325                                 errorf(&expression->base.source_position,
10326                                         "cannot convert to a pointer type");
10327                         } else if (warning.other && type != type_void_ptr) {
10328                                 warningf(&expression->base.source_position,
10329                                         "type of computed goto expression should be 'void*' not '%T'", type);
10330                         }
10331                         expression = create_implicit_cast(expression, type_void_ptr);
10332                 }
10333
10334                 statement->gotos.expression = expression;
10335         } else {
10336                 if (token.type != T_IDENTIFIER) {
10337                         if (GNU_MODE)
10338                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
10339                         else
10340                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
10341                         eat_until_anchor();
10342                         goto end_error;
10343                 }
10344                 symbol_t *symbol = token.v.symbol;
10345                 next_token();
10346
10347                 statement->gotos.label = get_label(symbol);
10348         }
10349
10350         /* remember the goto's in a list for later checking */
10351         *goto_anchor = &statement->gotos;
10352         goto_anchor  = &statement->gotos.next;
10353
10354         expect(';', end_error);
10355
10356         return statement;
10357 end_error:
10358         return create_invalid_statement();
10359 }
10360
10361 /**
10362  * Parse a continue statement.
10363  */
10364 static statement_t *parse_continue(void)
10365 {
10366         if (current_loop == NULL) {
10367                 errorf(HERE, "continue statement not within loop");
10368         }
10369
10370         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
10371
10372         eat(T_continue);
10373         expect(';', end_error);
10374
10375 end_error:
10376         return statement;
10377 }
10378
10379 /**
10380  * Parse a break statement.
10381  */
10382 static statement_t *parse_break(void)
10383 {
10384         if (current_switch == NULL && current_loop == NULL) {
10385                 errorf(HERE, "break statement not within loop or switch");
10386         }
10387
10388         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
10389
10390         eat(T_break);
10391         expect(';', end_error);
10392
10393 end_error:
10394         return statement;
10395 }
10396
10397 /**
10398  * Parse a __leave statement.
10399  */
10400 static statement_t *parse_leave_statement(void)
10401 {
10402         if (current_try == NULL) {
10403                 errorf(HERE, "__leave statement not within __try");
10404         }
10405
10406         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
10407
10408         eat(T___leave);
10409         expect(';', end_error);
10410
10411 end_error:
10412         return statement;
10413 }
10414
10415 /**
10416  * Check if a given entity represents a local variable.
10417  */
10418 static bool is_local_variable(const entity_t *entity)
10419 {
10420         if (entity->kind != ENTITY_VARIABLE)
10421                 return false;
10422
10423         switch ((storage_class_tag_t) entity->declaration.storage_class) {
10424         case STORAGE_CLASS_AUTO:
10425         case STORAGE_CLASS_REGISTER: {
10426                 const type_t *type = skip_typeref(entity->declaration.type);
10427                 if (is_type_function(type)) {
10428                         return false;
10429                 } else {
10430                         return true;
10431                 }
10432         }
10433         default:
10434                 return false;
10435         }
10436 }
10437
10438 /**
10439  * Check if a given expression represents a local variable.
10440  */
10441 static bool expression_is_local_variable(const expression_t *expression)
10442 {
10443         if (expression->base.kind != EXPR_REFERENCE) {
10444                 return false;
10445         }
10446         const entity_t *entity = expression->reference.entity;
10447         return is_local_variable(entity);
10448 }
10449
10450 /**
10451  * Check if a given expression represents a local variable and
10452  * return its declaration then, else return NULL.
10453  */
10454 entity_t *expression_is_variable(const expression_t *expression)
10455 {
10456         if (expression->base.kind != EXPR_REFERENCE) {
10457                 return NULL;
10458         }
10459         entity_t *entity = expression->reference.entity;
10460         if (entity->kind != ENTITY_VARIABLE)
10461                 return NULL;
10462
10463         return entity;
10464 }
10465
10466 /**
10467  * Parse a return statement.
10468  */
10469 static statement_t *parse_return(void)
10470 {
10471         eat(T_return);
10472
10473         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10474
10475         expression_t *return_value = NULL;
10476         if (token.type != ';') {
10477                 return_value = parse_expression();
10478                 mark_vars_read(return_value, NULL);
10479         }
10480
10481         const type_t *const func_type = skip_typeref(current_function->base.type);
10482         assert(is_type_function(func_type));
10483         type_t *const return_type = skip_typeref(func_type->function.return_type);
10484
10485         source_position_t const *const pos = &statement->base.source_position;
10486         if (return_value != NULL) {
10487                 type_t *return_value_type = skip_typeref(return_value->base.type);
10488
10489                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10490                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10491                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10492                                 /* Only warn in C mode, because GCC does the same */
10493                                 if (c_mode & _CXX || strict_mode) {
10494                                         errorf(pos,
10495                                                         "'return' with a value, in function returning 'void'");
10496                                 } else if (warning.other) {
10497                                         warningf(pos,
10498                                                         "'return' with a value, in function returning 'void'");
10499                                 }
10500                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10501                                 /* Only warn in C mode, because GCC does the same */
10502                                 if (strict_mode) {
10503                                         errorf(pos,
10504                                                         "'return' with expression in function return 'void'");
10505                                 } else if (warning.other) {
10506                                         warningf(pos,
10507                                                         "'return' with expression in function return 'void'");
10508                                 }
10509                         }
10510                 } else {
10511                         assign_error_t error = semantic_assign(return_type, return_value);
10512                         report_assign_error(error, return_type, return_value, "'return'",
10513                                         pos);
10514                 }
10515                 return_value = create_implicit_cast(return_value, return_type);
10516                 /* check for returning address of a local var */
10517                 if (warning.other && return_value != NULL
10518                                 && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10519                         const expression_t *expression = return_value->unary.value;
10520                         if (expression_is_local_variable(expression)) {
10521                                 warningf(pos, "function returns address of local variable");
10522                         }
10523                 }
10524         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10525                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10526                 if (c_mode & _CXX || strict_mode) {
10527                         errorf(pos,
10528                                         "'return' without value, in function returning non-void");
10529                 } else {
10530                         warningf(pos,
10531                                         "'return' without value, in function returning non-void");
10532                 }
10533         }
10534         statement->returns.value = return_value;
10535
10536         expect(';', end_error);
10537
10538 end_error:
10539         return statement;
10540 }
10541
10542 /**
10543  * Parse a declaration statement.
10544  */
10545 static statement_t *parse_declaration_statement(void)
10546 {
10547         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10548
10549         entity_t *before = current_scope->last_entity;
10550         if (GNU_MODE) {
10551                 parse_external_declaration();
10552         } else {
10553                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10554         }
10555
10556         declaration_statement_t *const decl  = &statement->declaration;
10557         entity_t                *const begin =
10558                 before != NULL ? before->base.next : current_scope->entities;
10559         decl->declarations_begin = begin;
10560         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10561
10562         return statement;
10563 }
10564
10565 /**
10566  * Parse an expression statement, ie. expr ';'.
10567  */
10568 static statement_t *parse_expression_statement(void)
10569 {
10570         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10571
10572         expression_t *const expr         = parse_expression();
10573         statement->expression.expression = expr;
10574         mark_vars_read(expr, ENT_ANY);
10575
10576         expect(';', end_error);
10577
10578 end_error:
10579         return statement;
10580 }
10581
10582 /**
10583  * Parse a microsoft __try { } __finally { } or
10584  * __try{ } __except() { }
10585  */
10586 static statement_t *parse_ms_try_statment(void)
10587 {
10588         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10589         eat(T___try);
10590
10591         PUSH_PARENT(statement);
10592
10593         ms_try_statement_t *rem = current_try;
10594         current_try = &statement->ms_try;
10595         statement->ms_try.try_statement = parse_compound_statement(false);
10596         current_try = rem;
10597
10598         POP_PARENT;
10599
10600         if (token.type == T___except) {
10601                 eat(T___except);
10602                 expect('(', end_error);
10603                 add_anchor_token(')');
10604                 expression_t *const expr = parse_expression();
10605                 mark_vars_read(expr, NULL);
10606                 type_t       *      type = skip_typeref(expr->base.type);
10607                 if (is_type_integer(type)) {
10608                         type = promote_integer(type);
10609                 } else if (is_type_valid(type)) {
10610                         errorf(&expr->base.source_position,
10611                                "__expect expression is not an integer, but '%T'", type);
10612                         type = type_error_type;
10613                 }
10614                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10615                 rem_anchor_token(')');
10616                 expect(')', end_error);
10617                 statement->ms_try.final_statement = parse_compound_statement(false);
10618         } else if (token.type == T__finally) {
10619                 eat(T___finally);
10620                 statement->ms_try.final_statement = parse_compound_statement(false);
10621         } else {
10622                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10623                 return create_invalid_statement();
10624         }
10625         return statement;
10626 end_error:
10627         return create_invalid_statement();
10628 }
10629
10630 static statement_t *parse_empty_statement(void)
10631 {
10632         if (warning.empty_statement) {
10633                 warningf(HERE, "statement is empty");
10634         }
10635         statement_t *const statement = create_empty_statement();
10636         eat(';');
10637         return statement;
10638 }
10639
10640 static statement_t *parse_local_label_declaration(void)
10641 {
10642         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10643
10644         eat(T___label__);
10645
10646         entity_t *begin = NULL, *end = NULL;
10647
10648         while (true) {
10649                 if (token.type != T_IDENTIFIER) {
10650                         parse_error_expected("while parsing local label declaration",
10651                                 T_IDENTIFIER, NULL);
10652                         goto end_error;
10653                 }
10654                 symbol_t *symbol = token.v.symbol;
10655                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10656                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10657                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10658                                symbol, &entity->base.source_position);
10659                 } else {
10660                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10661
10662                         entity->base.parent_scope    = current_scope;
10663                         entity->base.namespc         = NAMESPACE_LABEL;
10664                         entity->base.source_position = token.source_position;
10665                         entity->base.symbol          = symbol;
10666
10667                         if (end != NULL)
10668                                 end->base.next = entity;
10669                         end = entity;
10670                         if (begin == NULL)
10671                                 begin = entity;
10672
10673                         environment_push(entity);
10674                 }
10675                 next_token();
10676
10677                 if (token.type != ',')
10678                         break;
10679                 next_token();
10680         }
10681         eat(';');
10682 end_error:
10683         statement->declaration.declarations_begin = begin;
10684         statement->declaration.declarations_end   = end;
10685         return statement;
10686 }
10687
10688 static void parse_namespace_definition(void)
10689 {
10690         eat(T_namespace);
10691
10692         entity_t *entity = NULL;
10693         symbol_t *symbol = NULL;
10694
10695         if (token.type == T_IDENTIFIER) {
10696                 symbol = token.v.symbol;
10697                 next_token();
10698
10699                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10700                 if (entity       != NULL             &&
10701                                 entity->kind != ENTITY_NAMESPACE &&
10702                                 entity->base.parent_scope == current_scope) {
10703                         if (!is_error_entity(entity)) {
10704                                 error_redefined_as_different_kind(&token.source_position,
10705                                                 entity, ENTITY_NAMESPACE);
10706                         }
10707                         entity = NULL;
10708                 }
10709         }
10710
10711         if (entity == NULL) {
10712                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10713                 entity->base.symbol          = symbol;
10714                 entity->base.source_position = token.source_position;
10715                 entity->base.namespc         = NAMESPACE_NORMAL;
10716                 entity->base.parent_scope    = current_scope;
10717         }
10718
10719         if (token.type == '=') {
10720                 /* TODO: parse namespace alias */
10721                 panic("namespace alias definition not supported yet");
10722         }
10723
10724         environment_push(entity);
10725         append_entity(current_scope, entity);
10726
10727         size_t const  top       = environment_top();
10728         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10729
10730         expect('{', end_error);
10731         parse_externals();
10732         expect('}', end_error);
10733
10734 end_error:
10735         assert(current_scope == &entity->namespacee.members);
10736         scope_pop(old_scope);
10737         environment_pop_to(top);
10738 }
10739
10740 /**
10741  * Parse a statement.
10742  * There's also parse_statement() which additionally checks for
10743  * "statement has no effect" warnings
10744  */
10745 static statement_t *intern_parse_statement(void)
10746 {
10747         statement_t *statement = NULL;
10748
10749         /* declaration or statement */
10750         add_anchor_token(';');
10751         switch (token.type) {
10752         case T_IDENTIFIER: {
10753                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10754                 if (la1_type == ':') {
10755                         statement = parse_label_statement();
10756                 } else if (is_typedef_symbol(token.v.symbol)) {
10757                         statement = parse_declaration_statement();
10758                 } else {
10759                         /* it's an identifier, the grammar says this must be an
10760                          * expression statement. However it is common that users mistype
10761                          * declaration types, so we guess a bit here to improve robustness
10762                          * for incorrect programs */
10763                         switch (la1_type) {
10764                         case '&':
10765                         case '*':
10766                                 if (get_entity(token.v.symbol, NAMESPACE_NORMAL) != NULL)
10767                                         goto expression_statment;
10768                                 /* FALLTHROUGH */
10769
10770                         DECLARATION_START
10771                         case T_IDENTIFIER:
10772                                 statement = parse_declaration_statement();
10773                                 break;
10774
10775                         default:
10776 expression_statment:
10777                                 statement = parse_expression_statement();
10778                                 break;
10779                         }
10780                 }
10781                 break;
10782         }
10783
10784         case T___extension__:
10785                 /* This can be a prefix to a declaration or an expression statement.
10786                  * We simply eat it now and parse the rest with tail recursion. */
10787                 do {
10788                         next_token();
10789                 } while (token.type == T___extension__);
10790                 bool old_gcc_extension = in_gcc_extension;
10791                 in_gcc_extension       = true;
10792                 statement = intern_parse_statement();
10793                 in_gcc_extension = old_gcc_extension;
10794                 break;
10795
10796         DECLARATION_START
10797                 statement = parse_declaration_statement();
10798                 break;
10799
10800         case T___label__:
10801                 statement = parse_local_label_declaration();
10802                 break;
10803
10804         case ';':         statement = parse_empty_statement();         break;
10805         case '{':         statement = parse_compound_statement(false); break;
10806         case T___leave:   statement = parse_leave_statement();         break;
10807         case T___try:     statement = parse_ms_try_statment();         break;
10808         case T_asm:       statement = parse_asm_statement();           break;
10809         case T_break:     statement = parse_break();                   break;
10810         case T_case:      statement = parse_case_statement();          break;
10811         case T_continue:  statement = parse_continue();                break;
10812         case T_default:   statement = parse_default_statement();       break;
10813         case T_do:        statement = parse_do();                      break;
10814         case T_for:       statement = parse_for();                     break;
10815         case T_goto:      statement = parse_goto();                    break;
10816         case T_if:        statement = parse_if();                      break;
10817         case T_return:    statement = parse_return();                  break;
10818         case T_switch:    statement = parse_switch();                  break;
10819         case T_while:     statement = parse_while();                   break;
10820
10821         EXPRESSION_START
10822                 statement = parse_expression_statement();
10823                 break;
10824
10825         default:
10826                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10827                 statement = create_invalid_statement();
10828                 if (!at_anchor())
10829                         next_token();
10830                 break;
10831         }
10832         rem_anchor_token(';');
10833
10834         assert(statement != NULL
10835                         && statement->base.source_position.input_name != NULL);
10836
10837         return statement;
10838 }
10839
10840 /**
10841  * parse a statement and emits "statement has no effect" warning if needed
10842  * (This is really a wrapper around intern_parse_statement with check for 1
10843  *  single warning. It is needed, because for statement expressions we have
10844  *  to avoid the warning on the last statement)
10845  */
10846 static statement_t *parse_statement(void)
10847 {
10848         statement_t *statement = intern_parse_statement();
10849
10850         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10851                 expression_t *expression = statement->expression.expression;
10852                 if (!expression_has_effect(expression)) {
10853                         warningf(&expression->base.source_position,
10854                                         "statement has no effect");
10855                 }
10856         }
10857
10858         return statement;
10859 }
10860
10861 /**
10862  * Parse a compound statement.
10863  */
10864 static statement_t *parse_compound_statement(bool inside_expression_statement)
10865 {
10866         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10867
10868         PUSH_PARENT(statement);
10869
10870         eat('{');
10871         add_anchor_token('}');
10872         /* tokens, which can start a statement */
10873         /* TODO MS, __builtin_FOO */
10874         add_anchor_token('!');
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(T_CHARACTER_CONSTANT);
10883         add_anchor_token(T_COLONCOLON);
10884         add_anchor_token(T_FLOATINGPOINT);
10885         add_anchor_token(T_IDENTIFIER);
10886         add_anchor_token(T_INTEGER);
10887         add_anchor_token(T_MINUSMINUS);
10888         add_anchor_token(T_PLUSPLUS);
10889         add_anchor_token(T_STRING_LITERAL);
10890         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10891         add_anchor_token(T_WIDE_STRING_LITERAL);
10892         add_anchor_token(T__Bool);
10893         add_anchor_token(T__Complex);
10894         add_anchor_token(T__Imaginary);
10895         add_anchor_token(T___FUNCTION__);
10896         add_anchor_token(T___PRETTY_FUNCTION__);
10897         add_anchor_token(T___alignof__);
10898         add_anchor_token(T___attribute__);
10899         add_anchor_token(T___builtin_va_start);
10900         add_anchor_token(T___extension__);
10901         add_anchor_token(T___func__);
10902         add_anchor_token(T___imag__);
10903         add_anchor_token(T___label__);
10904         add_anchor_token(T___real__);
10905         add_anchor_token(T___thread);
10906         add_anchor_token(T_asm);
10907         add_anchor_token(T_auto);
10908         add_anchor_token(T_bool);
10909         add_anchor_token(T_break);
10910         add_anchor_token(T_case);
10911         add_anchor_token(T_char);
10912         add_anchor_token(T_class);
10913         add_anchor_token(T_const);
10914         add_anchor_token(T_const_cast);
10915         add_anchor_token(T_continue);
10916         add_anchor_token(T_default);
10917         add_anchor_token(T_delete);
10918         add_anchor_token(T_double);
10919         add_anchor_token(T_do);
10920         add_anchor_token(T_dynamic_cast);
10921         add_anchor_token(T_enum);
10922         add_anchor_token(T_extern);
10923         add_anchor_token(T_false);
10924         add_anchor_token(T_float);
10925         add_anchor_token(T_for);
10926         add_anchor_token(T_goto);
10927         add_anchor_token(T_if);
10928         add_anchor_token(T_inline);
10929         add_anchor_token(T_int);
10930         add_anchor_token(T_long);
10931         add_anchor_token(T_new);
10932         add_anchor_token(T_operator);
10933         add_anchor_token(T_register);
10934         add_anchor_token(T_reinterpret_cast);
10935         add_anchor_token(T_restrict);
10936         add_anchor_token(T_return);
10937         add_anchor_token(T_short);
10938         add_anchor_token(T_signed);
10939         add_anchor_token(T_sizeof);
10940         add_anchor_token(T_static);
10941         add_anchor_token(T_static_cast);
10942         add_anchor_token(T_struct);
10943         add_anchor_token(T_switch);
10944         add_anchor_token(T_template);
10945         add_anchor_token(T_this);
10946         add_anchor_token(T_throw);
10947         add_anchor_token(T_true);
10948         add_anchor_token(T_try);
10949         add_anchor_token(T_typedef);
10950         add_anchor_token(T_typeid);
10951         add_anchor_token(T_typename);
10952         add_anchor_token(T_typeof);
10953         add_anchor_token(T_union);
10954         add_anchor_token(T_unsigned);
10955         add_anchor_token(T_using);
10956         add_anchor_token(T_void);
10957         add_anchor_token(T_volatile);
10958         add_anchor_token(T_wchar_t);
10959         add_anchor_token(T_while);
10960
10961         size_t const  top       = environment_top();
10962         scope_t      *old_scope = scope_push(&statement->compound.scope);
10963
10964         statement_t **anchor            = &statement->compound.statements;
10965         bool          only_decls_so_far = true;
10966         while (token.type != '}') {
10967                 if (token.type == T_EOF) {
10968                         errorf(&statement->base.source_position,
10969                                "EOF while parsing compound statement");
10970                         break;
10971                 }
10972                 statement_t *sub_statement = intern_parse_statement();
10973                 if (is_invalid_statement(sub_statement)) {
10974                         /* an error occurred. if we are at an anchor, return */
10975                         if (at_anchor())
10976                                 goto end_error;
10977                         continue;
10978                 }
10979
10980                 if (warning.declaration_after_statement) {
10981                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10982                                 only_decls_so_far = false;
10983                         } else if (!only_decls_so_far) {
10984                                 warningf(&sub_statement->base.source_position,
10985                                          "ISO C90 forbids mixed declarations and code");
10986                         }
10987                 }
10988
10989                 *anchor = sub_statement;
10990
10991                 while (sub_statement->base.next != NULL)
10992                         sub_statement = sub_statement->base.next;
10993
10994                 anchor = &sub_statement->base.next;
10995         }
10996         next_token();
10997
10998         /* look over all statements again to produce no effect warnings */
10999         if (warning.unused_value) {
11000                 statement_t *sub_statement = statement->compound.statements;
11001                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
11002                         if (sub_statement->kind != STATEMENT_EXPRESSION)
11003                                 continue;
11004                         /* don't emit a warning for the last expression in an expression
11005                          * statement as it has always an effect */
11006                         if (inside_expression_statement && sub_statement->base.next == NULL)
11007                                 continue;
11008
11009                         expression_t *expression = sub_statement->expression.expression;
11010                         if (!expression_has_effect(expression)) {
11011                                 warningf(&expression->base.source_position,
11012                                          "statement has no effect");
11013                         }
11014                 }
11015         }
11016
11017 end_error:
11018         rem_anchor_token(T_while);
11019         rem_anchor_token(T_wchar_t);
11020         rem_anchor_token(T_volatile);
11021         rem_anchor_token(T_void);
11022         rem_anchor_token(T_using);
11023         rem_anchor_token(T_unsigned);
11024         rem_anchor_token(T_union);
11025         rem_anchor_token(T_typeof);
11026         rem_anchor_token(T_typename);
11027         rem_anchor_token(T_typeid);
11028         rem_anchor_token(T_typedef);
11029         rem_anchor_token(T_try);
11030         rem_anchor_token(T_true);
11031         rem_anchor_token(T_throw);
11032         rem_anchor_token(T_this);
11033         rem_anchor_token(T_template);
11034         rem_anchor_token(T_switch);
11035         rem_anchor_token(T_struct);
11036         rem_anchor_token(T_static_cast);
11037         rem_anchor_token(T_static);
11038         rem_anchor_token(T_sizeof);
11039         rem_anchor_token(T_signed);
11040         rem_anchor_token(T_short);
11041         rem_anchor_token(T_return);
11042         rem_anchor_token(T_restrict);
11043         rem_anchor_token(T_reinterpret_cast);
11044         rem_anchor_token(T_register);
11045         rem_anchor_token(T_operator);
11046         rem_anchor_token(T_new);
11047         rem_anchor_token(T_long);
11048         rem_anchor_token(T_int);
11049         rem_anchor_token(T_inline);
11050         rem_anchor_token(T_if);
11051         rem_anchor_token(T_goto);
11052         rem_anchor_token(T_for);
11053         rem_anchor_token(T_float);
11054         rem_anchor_token(T_false);
11055         rem_anchor_token(T_extern);
11056         rem_anchor_token(T_enum);
11057         rem_anchor_token(T_dynamic_cast);
11058         rem_anchor_token(T_do);
11059         rem_anchor_token(T_double);
11060         rem_anchor_token(T_delete);
11061         rem_anchor_token(T_default);
11062         rem_anchor_token(T_continue);
11063         rem_anchor_token(T_const_cast);
11064         rem_anchor_token(T_const);
11065         rem_anchor_token(T_class);
11066         rem_anchor_token(T_char);
11067         rem_anchor_token(T_case);
11068         rem_anchor_token(T_break);
11069         rem_anchor_token(T_bool);
11070         rem_anchor_token(T_auto);
11071         rem_anchor_token(T_asm);
11072         rem_anchor_token(T___thread);
11073         rem_anchor_token(T___real__);
11074         rem_anchor_token(T___label__);
11075         rem_anchor_token(T___imag__);
11076         rem_anchor_token(T___func__);
11077         rem_anchor_token(T___extension__);
11078         rem_anchor_token(T___builtin_va_start);
11079         rem_anchor_token(T___attribute__);
11080         rem_anchor_token(T___alignof__);
11081         rem_anchor_token(T___PRETTY_FUNCTION__);
11082         rem_anchor_token(T___FUNCTION__);
11083         rem_anchor_token(T__Imaginary);
11084         rem_anchor_token(T__Complex);
11085         rem_anchor_token(T__Bool);
11086         rem_anchor_token(T_WIDE_STRING_LITERAL);
11087         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
11088         rem_anchor_token(T_STRING_LITERAL);
11089         rem_anchor_token(T_PLUSPLUS);
11090         rem_anchor_token(T_MINUSMINUS);
11091         rem_anchor_token(T_INTEGER);
11092         rem_anchor_token(T_IDENTIFIER);
11093         rem_anchor_token(T_FLOATINGPOINT);
11094         rem_anchor_token(T_COLONCOLON);
11095         rem_anchor_token(T_CHARACTER_CONSTANT);
11096         rem_anchor_token('~');
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         assert(current_scope == &statement->compound.scope);
11106         scope_pop(old_scope);
11107         environment_pop_to(top);
11108
11109         POP_PARENT;
11110         return statement;
11111 }
11112
11113 /**
11114  * Check for unused global static functions and variables
11115  */
11116 static void check_unused_globals(void)
11117 {
11118         if (!warning.unused_function && !warning.unused_variable)
11119                 return;
11120
11121         for (const entity_t *entity = file_scope->entities; entity != NULL;
11122              entity = entity->base.next) {
11123                 if (!is_declaration(entity))
11124                         continue;
11125
11126                 const declaration_t *declaration = &entity->declaration;
11127                 if (declaration->used                  ||
11128                     declaration->modifiers & DM_UNUSED ||
11129                     declaration->modifiers & DM_USED   ||
11130                     declaration->storage_class != STORAGE_CLASS_STATIC)
11131                         continue;
11132
11133                 type_t *const type = declaration->type;
11134                 const char *s;
11135                 if (entity->kind == ENTITY_FUNCTION) {
11136                         /* inhibit warning for static inline functions */
11137                         if (entity->function.is_inline)
11138                                 continue;
11139
11140                         s = entity->function.statement != NULL ? "defined" : "declared";
11141                 } else {
11142                         s = "defined";
11143                 }
11144
11145                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
11146                         type, declaration->base.symbol, s);
11147         }
11148 }
11149
11150 static void parse_global_asm(void)
11151 {
11152         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
11153
11154         eat(T_asm);
11155         expect('(', end_error);
11156
11157         statement->asms.asm_text = parse_string_literals();
11158         statement->base.next     = unit->global_asm;
11159         unit->global_asm         = statement;
11160
11161         expect(')', end_error);
11162         expect(';', end_error);
11163
11164 end_error:;
11165 }
11166
11167 static void parse_linkage_specification(void)
11168 {
11169         eat(T_extern);
11170         assert(token.type == T_STRING_LITERAL);
11171
11172         const char *linkage = parse_string_literals().begin;
11173
11174         linkage_kind_t old_linkage = current_linkage;
11175         linkage_kind_t new_linkage;
11176         if (strcmp(linkage, "C") == 0) {
11177                 new_linkage = LINKAGE_C;
11178         } else if (strcmp(linkage, "C++") == 0) {
11179                 new_linkage = LINKAGE_CXX;
11180         } else {
11181                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
11182                 new_linkage = LINKAGE_INVALID;
11183         }
11184         current_linkage = new_linkage;
11185
11186         if (token.type == '{') {
11187                 next_token();
11188                 parse_externals();
11189                 expect('}', end_error);
11190         } else {
11191                 parse_external();
11192         }
11193
11194 end_error:
11195         assert(current_linkage == new_linkage);
11196         current_linkage = old_linkage;
11197 }
11198
11199 static void parse_external(void)
11200 {
11201         switch (token.type) {
11202                 DECLARATION_START_NO_EXTERN
11203                 case T_IDENTIFIER:
11204                 case T___extension__:
11205                 /* tokens below are for implicit int */
11206                 case '&': /* & x; -> int& x; (and error later, because C++ has no
11207                              implicit int) */
11208                 case '*': /* * x; -> int* x; */
11209                 case '(': /* (x); -> int (x); */
11210                         parse_external_declaration();
11211                         return;
11212
11213                 case T_extern:
11214                         if (look_ahead(1)->type == T_STRING_LITERAL) {
11215                                 parse_linkage_specification();
11216                         } else {
11217                                 parse_external_declaration();
11218                         }
11219                         return;
11220
11221                 case T_asm:
11222                         parse_global_asm();
11223                         return;
11224
11225                 case T_namespace:
11226                         parse_namespace_definition();
11227                         return;
11228
11229                 case ';':
11230                         if (!strict_mode) {
11231                                 if (warning.other)
11232                                         warningf(HERE, "stray ';' outside of function");
11233                                 next_token();
11234                                 return;
11235                         }
11236                         /* FALLTHROUGH */
11237
11238                 default:
11239                         errorf(HERE, "stray %K outside of function", &token);
11240                         if (token.type == '(' || token.type == '{' || token.type == '[')
11241                                 eat_until_matching_token(token.type);
11242                         next_token();
11243                         return;
11244         }
11245 }
11246
11247 static void parse_externals(void)
11248 {
11249         add_anchor_token('}');
11250         add_anchor_token(T_EOF);
11251
11252 #ifndef NDEBUG
11253         unsigned char token_anchor_copy[T_LAST_TOKEN];
11254         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
11255 #endif
11256
11257         while (token.type != T_EOF && token.type != '}') {
11258 #ifndef NDEBUG
11259                 bool anchor_leak = false;
11260                 for (int i = 0; i != T_LAST_TOKEN; ++i) {
11261                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
11262                         if (count != 0) {
11263                                 errorf(HERE, "Leaked anchor token %k %d times", i, count);
11264                                 anchor_leak = true;
11265                         }
11266                 }
11267                 if (in_gcc_extension) {
11268                         errorf(HERE, "Leaked __extension__");
11269                         anchor_leak = true;
11270                 }
11271
11272                 if (anchor_leak)
11273                         abort();
11274 #endif
11275
11276                 parse_external();
11277         }
11278
11279         rem_anchor_token(T_EOF);
11280         rem_anchor_token('}');
11281 }
11282
11283 /**
11284  * Parse a translation unit.
11285  */
11286 static void parse_translation_unit(void)
11287 {
11288         add_anchor_token(T_EOF);
11289
11290         while (true) {
11291                 parse_externals();
11292
11293                 if (token.type == T_EOF)
11294                         break;
11295
11296                 errorf(HERE, "stray %K outside of function", &token);
11297                 if (token.type == '(' || token.type == '{' || token.type == '[')
11298                         eat_until_matching_token(token.type);
11299                 next_token();
11300         }
11301 }
11302
11303 /**
11304  * Parse the input.
11305  *
11306  * @return  the translation unit or NULL if errors occurred.
11307  */
11308 void start_parsing(void)
11309 {
11310         environment_stack = NEW_ARR_F(stack_entry_t, 0);
11311         label_stack       = NEW_ARR_F(stack_entry_t, 0);
11312         diagnostic_count  = 0;
11313         error_count       = 0;
11314         warning_count     = 0;
11315
11316         type_set_output(stderr);
11317         ast_set_output(stderr);
11318
11319         assert(unit == NULL);
11320         unit = allocate_ast_zero(sizeof(unit[0]));
11321
11322         assert(file_scope == NULL);
11323         file_scope = &unit->scope;
11324
11325         assert(current_scope == NULL);
11326         scope_push(&unit->scope);
11327
11328         create_gnu_builtins();
11329         if (c_mode & _MS)
11330                 create_microsoft_intrinsics();
11331 }
11332
11333 translation_unit_t *finish_parsing(void)
11334 {
11335         assert(current_scope == &unit->scope);
11336         scope_pop(NULL);
11337
11338         assert(file_scope == &unit->scope);
11339         check_unused_globals();
11340         file_scope = NULL;
11341
11342         DEL_ARR_F(environment_stack);
11343         DEL_ARR_F(label_stack);
11344
11345         translation_unit_t *result = unit;
11346         unit = NULL;
11347         return result;
11348 }
11349
11350 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
11351  * are given length one. */
11352 static void complete_incomplete_arrays(void)
11353 {
11354         size_t n = ARR_LEN(incomplete_arrays);
11355         for (size_t i = 0; i != n; ++i) {
11356                 declaration_t *const decl      = incomplete_arrays[i];
11357                 type_t        *const orig_type = decl->type;
11358                 type_t        *const type      = skip_typeref(orig_type);
11359
11360                 if (!is_type_incomplete(type))
11361                         continue;
11362
11363                 if (warning.other) {
11364                         warningf(&decl->base.source_position,
11365                                         "array '%#T' assumed to have one element",
11366                                         orig_type, decl->base.symbol);
11367                 }
11368
11369                 type_t *const new_type = duplicate_type(type);
11370                 new_type->array.size_constant     = true;
11371                 new_type->array.has_implicit_size = true;
11372                 new_type->array.size              = 1;
11373
11374                 type_t *const result = identify_new_type(new_type);
11375
11376                 decl->type = result;
11377         }
11378 }
11379
11380 void parse(void)
11381 {
11382         lookahead_bufpos = 0;
11383         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
11384                 next_token();
11385         }
11386         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
11387         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
11388         parse_translation_unit();
11389         complete_incomplete_arrays();
11390         DEL_ARR_F(incomplete_arrays);
11391         incomplete_arrays = NULL;
11392 }
11393
11394 /**
11395  * create a builtin function.
11396  */
11397 static entity_t *create_builtin_function(builtin_kind_t kind, const char *name, type_t *function_type)
11398 {
11399         symbol_t *symbol = symbol_table_insert(name);
11400         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
11401         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
11402         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
11403         entity->declaration.type                   = function_type;
11404         entity->declaration.implicit               = true;
11405         entity->base.symbol                        = symbol;
11406         entity->base.source_position               = builtin_source_position;
11407
11408         entity->function.btk                       = kind;
11409
11410         record_entity(entity, /*is_definition=*/false);
11411         return entity;
11412 }
11413
11414
11415 /**
11416  * Create predefined gnu builtins.
11417  */
11418 static void create_gnu_builtins(void)
11419 {
11420 #define GNU_BUILTIN(a, b) create_builtin_function(bk_gnu_builtin_##a, "__builtin_" #a, b)
11421
11422         GNU_BUILTIN(alloca,         make_function_1_type(type_void_ptr, type_size_t));
11423         GNU_BUILTIN(huge_val,       make_function_0_type(type_double));
11424         GNU_BUILTIN(inf,            make_function_0_type(type_double));
11425         GNU_BUILTIN(inff,           make_function_0_type(type_float));
11426         GNU_BUILTIN(infl,           make_function_0_type(type_long_double));
11427         GNU_BUILTIN(nan,            make_function_1_type(type_double, type_char_ptr));
11428         GNU_BUILTIN(nanf,           make_function_1_type(type_float, type_char_ptr));
11429         GNU_BUILTIN(nanl,           make_function_1_type(type_long_double, type_char_ptr));
11430         GNU_BUILTIN(va_end,         make_function_1_type(type_void, type_valist));
11431         GNU_BUILTIN(expect,         make_function_2_type(type_long, type_long, type_long));
11432         GNU_BUILTIN(return_address, make_function_1_type(type_void_ptr, type_unsigned_int));
11433         GNU_BUILTIN(frame_address,  make_function_1_type(type_void_ptr, type_unsigned_int));
11434         GNU_BUILTIN(ffs,            make_function_1_type(type_int, type_unsigned_int));
11435         GNU_BUILTIN(clz,            make_function_1_type(type_int, type_unsigned_int));
11436         GNU_BUILTIN(ctz,            make_function_1_type(type_int, type_unsigned_int));
11437         GNU_BUILTIN(popcount,       make_function_1_type(type_int, type_unsigned_int));
11438         GNU_BUILTIN(parity,         make_function_1_type(type_int, type_unsigned_int));
11439         GNU_BUILTIN(prefetch,       make_function_1_type_variadic(type_float, type_void_ptr));
11440         GNU_BUILTIN(trap,           make_function_0_type_noreturn(type_void));
11441
11442 #undef GNU_BUILTIN
11443 }
11444
11445 /**
11446  * Create predefined MS intrinsics.
11447  */
11448 static void create_microsoft_intrinsics(void)
11449 {
11450 #define MS_BUILTIN(a, b) create_builtin_function(bk_ms##a, #a, b)
11451
11452         /* intrinsics for all architectures */
11453         MS_BUILTIN(_rotl,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11454         MS_BUILTIN(_rotr,                  make_function_2_type(type_unsigned_int,   type_unsigned_int, type_int));
11455         MS_BUILTIN(_rotl64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11456         MS_BUILTIN(_rotr64,                make_function_2_type(type_unsigned_int64, type_unsigned_int64, type_int));
11457         MS_BUILTIN(_byteswap_ushort,       make_function_1_type(type_unsigned_short, type_unsigned_short));
11458         MS_BUILTIN(_byteswap_ulong,        make_function_1_type(type_unsigned_long,  type_unsigned_long));
11459         MS_BUILTIN(_byteswap_uint64,       make_function_1_type(type_unsigned_int64, type_unsigned_int64));
11460
11461         MS_BUILTIN(__debugbreak,    make_function_0_type(type_void));
11462         MS_BUILTIN(_ReturnAddress,  make_function_0_type(type_void_ptr));
11463         MS_BUILTIN(__popcount,      make_function_1_type(type_unsigned_int, type_unsigned_int));
11464
11465         /* x86/x64 only */
11466         MS_BUILTIN(_enable,                make_function_0_type(type_void));
11467         MS_BUILTIN(_disable,               make_function_0_type(type_void));
11468         MS_BUILTIN(__inbyte,               make_function_1_type(type_unsigned_char, type_unsigned_short));
11469         MS_BUILTIN(__inword,               make_function_1_type(type_unsigned_short, type_unsigned_short));
11470         MS_BUILTIN(__indword,              make_function_1_type(type_unsigned_long, type_unsigned_short));
11471         MS_BUILTIN(__outbyte,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_char));
11472         MS_BUILTIN(__outword,              make_function_2_type(type_void, type_unsigned_short, type_unsigned_short));
11473         MS_BUILTIN(__outdword,             make_function_2_type(type_void, type_unsigned_short, type_unsigned_long));
11474         MS_BUILTIN(__ud2,                  make_function_0_type_noreturn(type_void));
11475         MS_BUILTIN(_BitScanForward,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11476         MS_BUILTIN(_BitScanReverse,        make_function_2_type(type_unsigned_char, type_unsigned_long_ptr, type_unsigned_long));
11477         MS_BUILTIN(_InterlockedExchange,   make_function_2_type(type_long, type_long_ptr, type_long));
11478         MS_BUILTIN(_InterlockedExchange64, make_function_2_type(type_int64, type_int64_ptr, type_int64));
11479
11480         if (machine_size <= 32) {
11481                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int));
11482                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int));
11483         } else {
11484                 MS_BUILTIN(__readeflags,           make_function_0_type(type_unsigned_int64));
11485                 MS_BUILTIN(__writeeflags,          make_function_1_type(type_void, type_unsigned_int64));
11486         }
11487
11488 #undef MS_BUILTIN
11489 }
11490
11491 /**
11492  * Initialize the parser.
11493  */
11494 void init_parser(void)
11495 {
11496         sym_anonymous = symbol_table_insert("<anonymous>");
11497
11498         if (c_mode & _MS) {
11499                 /* add predefined symbols for extended-decl-modifier */
11500                 sym_align         = symbol_table_insert("align");
11501                 sym_allocate      = symbol_table_insert("allocate");
11502                 sym_dllimport     = symbol_table_insert("dllimport");
11503                 sym_dllexport     = symbol_table_insert("dllexport");
11504                 sym_naked         = symbol_table_insert("naked");
11505                 sym_noinline      = symbol_table_insert("noinline");
11506                 sym_returns_twice = symbol_table_insert("returns_twice");
11507                 sym_noreturn      = symbol_table_insert("noreturn");
11508                 sym_nothrow       = symbol_table_insert("nothrow");
11509                 sym_novtable      = symbol_table_insert("novtable");
11510                 sym_property      = symbol_table_insert("property");
11511                 sym_get           = symbol_table_insert("get");
11512                 sym_put           = symbol_table_insert("put");
11513                 sym_selectany     = symbol_table_insert("selectany");
11514                 sym_thread        = symbol_table_insert("thread");
11515                 sym_uuid          = symbol_table_insert("uuid");
11516                 sym_deprecated    = symbol_table_insert("deprecated");
11517                 sym_restrict      = symbol_table_insert("restrict");
11518                 sym_noalias       = symbol_table_insert("noalias");
11519         }
11520         memset(token_anchor_set, 0, sizeof(token_anchor_set));
11521
11522         init_expression_parsers();
11523         obstack_init(&temp_obst);
11524
11525         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
11526         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
11527 }
11528
11529 /**
11530  * Terminate the parser.
11531  */
11532 void exit_parser(void)
11533 {
11534         obstack_free(&temp_obst, NULL);
11535 }