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 "lang_features.h"
  37 #include "warning.h"
  38 #include "adt/bitfiddle.h"
  39 #include "adt/error.h"
  40 #include "adt/array.h"
  41
  42 //#define PRINT_TOKENS
  43 #define MAX_LOOKAHEAD 2
  44
  45 typedef struct {
  46         declaration_t *old_declaration;
  47         symbol_t      *symbol;
  48         unsigned short namespc;
  49 } stack_entry_t;
  50
  51 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  52 struct declaration_specifiers_t {
  53         source_position_t  source_position;
  54         unsigned char      declared_storage_class;
  55         bool               is_inline;
  56         decl_modifiers_t   decl_modifiers;
  57         type_t            *type;
  58 };
  59
  60 /**
  61  * An environment for parsing initializers (and compound literals).
  62  */
  63 typedef struct parse_initializer_env_t {
  64         type_t        *type;        /**< the type of the initializer. In case of an
  65                                          array type with unspecified size this gets
  66                                          adjusted to the actual size. */
  67         declaration_t *declaration; /**< the declaration that is initialized if any */
  68         bool           must_be_constant;
  69 } parse_initializer_env_t;
  70
  71 typedef declaration_t* (*parsed_declaration_func) (declaration_t *declaration);
  72
  73 static token_t             token;
  74 static token_t             lookahead_buffer[MAX_LOOKAHEAD];
  75 static int                 lookahead_bufpos;
  76 static stack_entry_t      *environment_stack = NULL;
  77 static stack_entry_t      *label_stack       = NULL;
  78 static scope_t            *global_scope      = NULL;
  79 static scope_t            *scope             = NULL;
  80 static declaration_t      *last_declaration  = NULL;
  81 static declaration_t      *current_function  = NULL;
  82 static switch_statement_t *current_switch    = NULL;
  83 static statement_t        *current_loop      = NULL;
  84 static goto_statement_t   *goto_first        = NULL;
  85 static goto_statement_t   *goto_last         = NULL;
  86 static label_statement_t  *label_first       = NULL;
  87 static label_statement_t  *label_last        = NULL;
  88 static struct obstack      temp_obst;
  89
  90 /** The current source position. */
  91 #define HERE token.source_position
  92
  93 static type_t *type_valist;
  94
  95 static statement_t *parse_compound_statement(void);
  96 static statement_t *parse_statement(void);
  97
  98 static expression_t *parse_sub_expression(unsigned precedence);
  99 static expression_t *parse_expression(void);
 100 static type_t       *parse_typename(void);
 101
 102 static void parse_compound_type_entries(declaration_t *compound_declaration);
 103 static declaration_t *parse_declarator(
 104                 const declaration_specifiers_t *specifiers, bool may_be_abstract);
 105 static declaration_t *record_declaration(declaration_t *declaration);
 106
 107 static void semantic_comparison(binary_expression_t *expression);
 108
 109 #define STORAGE_CLASSES     \
 110         case T_typedef:         \
 111         case T_extern:          \
 112         case T_static:          \
 113         case T_auto:            \
 114         case T_register:
 115
 116 #define TYPE_QUALIFIERS     \
 117         case T_const:           \
 118         case T_restrict:        \
 119         case T_volatile:        \
 120         case T_inline:          \
 121         case T_forceinline:
 122
 123 #ifdef PROVIDE_COMPLEX
 124 #define COMPLEX_SPECIFIERS  \
 125         case T__Complex:
 126 #define IMAGINARY_SPECIFIERS \
 127         case T__Imaginary:
 128 #else
 129 #define COMPLEX_SPECIFIERS
 130 #define IMAGINARY_SPECIFIERS
 131 #endif
 132
 133 #define TYPE_SPECIFIERS       \
 134         case T_void:              \
 135         case T_char:              \
 136         case T_short:             \
 137         case T_int:               \
 138         case T_long:              \
 139         case T_float:             \
 140         case T_double:            \
 141         case T_signed:            \
 142         case T_unsigned:          \
 143         case T__Bool:             \
 144         case T_struct:            \
 145         case T_union:             \
 146         case T_enum:              \
 147         case T___typeof__:        \
 148         case T___builtin_va_list: \
 149         COMPLEX_SPECIFIERS        \
 150         IMAGINARY_SPECIFIERS
 151
 152 #define DECLARATION_START   \
 153         STORAGE_CLASSES         \
 154         TYPE_QUALIFIERS         \
 155         TYPE_SPECIFIERS
 156
 157 #define TYPENAME_START      \
 158         TYPE_QUALIFIERS         \
 159         TYPE_SPECIFIERS
 160
 161 /**
 162  * Allocate an AST node with given size and
 163  * initialize all fields with zero.
 164  */
 165 static void *allocate_ast_zero(size_t size)
 166 {
 167         void *res = allocate_ast(size);
 168         memset(res, 0, size);
 169         return res;
 170 }
 171
 172 static declaration_t *allocate_declaration_zero(void)
 173 {
 174         declaration_t *declaration = allocate_ast_zero(sizeof(declaration_t));
 175         declaration->type = type_error_type;
 176         return declaration;
 177 }
 178
 179 /**
 180  * Returns the size of a statement node.
 181  *
 182  * @param kind  the statement kind
 183  */
 184 static size_t get_statement_struct_size(statement_kind_t kind)
 185 {
 186         static const size_t sizes[] = {
 187                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 188                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 189                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 190                 [STATEMENT_IF]          = sizeof(if_statement_t),
 191                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 192                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 193                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 194                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 195                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 196                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 197                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 198                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 199                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 200                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 201                 [STATEMENT_ASM]         = sizeof(asm_statement_t)
 202         };
 203         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 204         assert(sizes[kind] != 0);
 205         return sizes[kind];
 206 }
 207
 208 /**
 209  * Allocate a statement node of given kind and initialize all
 210  * fields with zero.
 211  */
 212 static statement_t *allocate_statement_zero(statement_kind_t kind)
 213 {
 214         size_t       size = get_statement_struct_size(kind);
 215         statement_t *res  = allocate_ast_zero(size);
 216
 217         res->base.kind = kind;
 218         return res;
 219 }
 220
 221 /**
 222  * Returns the size of an expression node.
 223  *
 224  * @param kind  the expression kind
 225  */
 226 static size_t get_expression_struct_size(expression_kind_t kind)
 227 {
 228         static const size_t sizes[] = {
 229                 [EXPR_INVALID]                 = sizeof(expression_base_t),
 230                 [EXPR_REFERENCE]               = sizeof(reference_expression_t),
 231                 [EXPR_CONST]                   = sizeof(const_expression_t),
 232                 [EXPR_CHARACTER_CONSTANT]      = sizeof(const_expression_t),
 233                 [EXPR_WIDE_CHARACTER_CONSTANT] = sizeof(const_expression_t),
 234                 [EXPR_STRING_LITERAL]          = sizeof(string_literal_expression_t),
 235                 [EXPR_WIDE_STRING_LITERAL]   = sizeof(wide_string_literal_expression_t),
 236                 [EXPR_COMPOUND_LITERAL]        = sizeof(compound_literal_expression_t),
 237                 [EXPR_CALL]                    = sizeof(call_expression_t),
 238                 [EXPR_UNARY_FIRST]             = sizeof(unary_expression_t),
 239                 [EXPR_BINARY_FIRST]            = sizeof(binary_expression_t),
 240                 [EXPR_CONDITIONAL]             = sizeof(conditional_expression_t),
 241                 [EXPR_SELECT]                  = sizeof(select_expression_t),
 242                 [EXPR_ARRAY_ACCESS]            = sizeof(array_access_expression_t),
 243                 [EXPR_SIZEOF]                  = sizeof(typeprop_expression_t),
 244                 [EXPR_ALIGNOF]                 = sizeof(typeprop_expression_t),
 245                 [EXPR_CLASSIFY_TYPE]           = sizeof(classify_type_expression_t),
 246                 [EXPR_FUNCTION]                = sizeof(string_literal_expression_t),
 247                 [EXPR_PRETTY_FUNCTION]         = sizeof(string_literal_expression_t),
 248                 [EXPR_BUILTIN_SYMBOL]          = sizeof(builtin_symbol_expression_t),
 249                 [EXPR_BUILTIN_CONSTANT_P]      = sizeof(builtin_constant_expression_t),
 250                 [EXPR_BUILTIN_PREFETCH]        = sizeof(builtin_prefetch_expression_t),
 251                 [EXPR_OFFSETOF]                = sizeof(offsetof_expression_t),
 252                 [EXPR_VA_START]                = sizeof(va_start_expression_t),
 253                 [EXPR_VA_ARG]                  = sizeof(va_arg_expression_t),
 254                 [EXPR_STATEMENT]               = sizeof(statement_expression_t),
 255         };
 256         if(kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 257                 return sizes[EXPR_UNARY_FIRST];
 258         }
 259         if(kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 260                 return sizes[EXPR_BINARY_FIRST];
 261         }
 262         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 263         assert(sizes[kind] != 0);
 264         return sizes[kind];
 265 }
 266
 267 /**
 268  * Allocate an expression node of given kind and initialize all
 269  * fields with zero.
 270  */
 271 static expression_t *allocate_expression_zero(expression_kind_t kind)
 272 {
 273         size_t        size = get_expression_struct_size(kind);
 274         expression_t *res  = allocate_ast_zero(size);
 275
 276         res->base.kind = kind;
 277         res->base.type = type_error_type;
 278         return res;
 279 }
 280
 281 /**
 282  * Returns the size of a type node.
 283  *
 284  * @param kind  the type kind
 285  */
 286 static size_t get_type_struct_size(type_kind_t kind)
 287 {
 288         static const size_t sizes[] = {
 289                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 290                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 291                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 292                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 293                 [TYPE_ENUM]            = sizeof(enum_type_t),
 294                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 295                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 296                 [TYPE_ARRAY]           = sizeof(array_type_t),
 297                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 298                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 299                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 300         };
 301         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 302         assert(kind <= TYPE_TYPEOF);
 303         assert(sizes[kind] != 0);
 304         return sizes[kind];
 305 }
 306
 307 /**
 308  * Allocate a type node of given kind and initialize all
 309  * fields with zero.
 310  */
 311 static type_t *allocate_type_zero(type_kind_t kind, source_position_t source_position)
 312 {
 313         size_t  size = get_type_struct_size(kind);
 314         type_t *res  = obstack_alloc(type_obst, size);
 315         memset(res, 0, size);
 316
 317         res->base.kind            = kind;
 318         res->base.source_position = source_position;
 319         return res;
 320 }
 321
 322 /**
 323  * Returns the size of an initializer node.
 324  *
 325  * @param kind  the initializer kind
 326  */
 327 static size_t get_initializer_size(initializer_kind_t kind)
 328 {
 329         static const size_t sizes[] = {
 330                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 331                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 332                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 333                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 334                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 335         };
 336         assert(kind < sizeof(sizes) / sizeof(*sizes));
 337         assert(sizes[kind] != 0);
 338         return sizes[kind];
 339 }
 340
 341 /**
 342  * Allocate an initializer node of given kind and initialize all
 343  * fields with zero.
 344  */
 345 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 346 {
 347         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 348         result->kind          = kind;
 349
 350         return result;
 351 }
 352
 353 /**
 354  * Free a type from the type obstack.
 355  */
 356 static void free_type(void *type)
 357 {
 358         obstack_free(type_obst, type);
 359 }
 360
 361 /**
 362  * Returns the index of the top element of the environment stack.
 363  */
 364 static size_t environment_top(void)
 365 {
 366         return ARR_LEN(environment_stack);
 367 }
 368
 369 /**
 370  * Returns the index of the top element of the label stack.
 371  */
 372 static size_t label_top(void)
 373 {
 374         return ARR_LEN(label_stack);
 375 }
 376
 377
 378 /**
 379  * Return the next token.
 380  */
 381 static inline void next_token(void)
 382 {
 383         token                              = lookahead_buffer[lookahead_bufpos];
 384         lookahead_buffer[lookahead_bufpos] = lexer_token;
 385         lexer_next_token();
 386
 387         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 388
 389 #ifdef PRINT_TOKENS
 390         print_token(stderr, &token);
 391         fprintf(stderr, "\n");
 392 #endif
 393 }
 394
 395 /**
 396  * Return the next token with a given lookahead.
 397  */
 398 static inline const token_t *look_ahead(int num)
 399 {
 400         assert(num > 0 && num <= MAX_LOOKAHEAD);
 401         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 402         return &lookahead_buffer[pos];
 403 }
 404
 405 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
 406
 407 /**
 408  * Report a parse error because an expected token was not found.
 409  */
 410 static void parse_error_expected(const char *message, ...)
 411 {
 412         if(message != NULL) {
 413                 errorf(HERE, "%s", message);
 414         }
 415         va_list ap;
 416         va_start(ap, message);
 417         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 418         va_end(ap);
 419 }
 420
 421 /**
 422  * Report a type error.
 423  */
 424 static void type_error(const char *msg, const source_position_t source_position,
 425                        type_t *type)
 426 {
 427         errorf(source_position, "%s, but found type '%T'", msg, type);
 428 }
 429
 430 /**
 431  * Report an incompatible type.
 432  */
 433 static void type_error_incompatible(const char *msg,
 434                 const source_position_t source_position, type_t *type1, type_t *type2)
 435 {
 436         errorf(source_position, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 437 }
 438
 439 /**
 440  * Eat an complete block, ie. '{ ... }'.
 441  */
 442 static void eat_block(void)
 443 {
 444         if(token.type == '{')
 445                 next_token();
 446
 447         while(token.type != '}') {
 448                 if(token.type == T_EOF)
 449                         return;
 450                 if(token.type == '{') {
 451                         eat_block();
 452                         continue;
 453                 }
 454                 next_token();
 455         }
 456         eat('}');
 457 }
 458
 459 /**
 460  * Eat a statement until an ';' token.
 461  */
 462 static void eat_statement(void)
 463 {
 464         while(token.type != ';') {
 465                 if(token.type == T_EOF)
 466                         return;
 467                 if(token.type == '}')
 468                         return;
 469                 if(token.type == '{') {
 470                         eat_block();
 471                         continue;
 472                 }
 473                 next_token();
 474         }
 475         eat(';');
 476 }
 477
 478 /**
 479  * Eat a parenthesed term, ie. '( ... )'.
 480  */
 481 static void eat_paren(void)
 482 {
 483         if(token.type == '(')
 484                 next_token();
 485
 486         while(token.type != ')') {
 487                 if(token.type == T_EOF)
 488                         return;
 489                 if(token.type == ')' || token.type == ';' || token.type == '}') {
 490                         return;
 491                 }
 492                 if(token.type == ')') {
 493                         next_token();
 494                         return;
 495                 }
 496                 if(token.type == '(') {
 497                         eat_paren();
 498                         continue;
 499                 }
 500                 if(token.type == '{') {
 501                         eat_block();
 502                         continue;
 503                 }
 504                 next_token();
 505         }
 506 }
 507
 508 /**
 509  * Expect the the current token is the expected token.
 510  * If not, generate an error, eat the current statement,
 511  * and goto the end_error label.
 512  */
 513 #define expect(expected)                           \
 514         do {                                           \
 515     if(UNLIKELY(token.type != (expected))) {       \
 516         parse_error_expected(NULL, (expected), 0); \
 517         eat_statement();                           \
 518         goto end_error;                            \
 519     }                                              \
 520     next_token();                                  \
 521         } while(0)
 522
 523 #define expect_block(expected)                     \
 524         do {                                           \
 525     if(UNLIKELY(token.type != (expected))) {       \
 526         parse_error_expected(NULL, (expected), 0); \
 527         eat_block();                               \
 528         return NULL;                               \
 529     }                                              \
 530     next_token();                                  \
 531         } while(0)
 532
 533 static void set_scope(scope_t *new_scope)
 534 {
 535         if(scope != NULL) {
 536                 scope->last_declaration = last_declaration;
 537         }
 538         scope = new_scope;
 539
 540         last_declaration = new_scope->last_declaration;
 541 }
 542
 543 /**
 544  * Search a symbol in a given namespace and returns its declaration or
 545  * NULL if this symbol was not found.
 546  */
 547 static declaration_t *get_declaration(const symbol_t *const symbol,
 548                                       const namespace_t namespc)
 549 {
 550         declaration_t *declaration = symbol->declaration;
 551         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 552                 if(declaration->namespc == namespc)
 553                         return declaration;
 554         }
 555
 556         return NULL;
 557 }
 558
 559 /**
 560  * pushs an environment_entry on the environment stack and links the
 561  * corresponding symbol to the new entry
 562  */
 563 static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
 564 {
 565         symbol_t    *symbol  = declaration->symbol;
 566         namespace_t  namespc = (namespace_t) declaration->namespc;
 567
 568         /* replace/add declaration into declaration list of the symbol */
 569         declaration_t *iter = symbol->declaration;
 570         if (iter == NULL) {
 571                 symbol->declaration = declaration;
 572         } else {
 573                 declaration_t *iter_last = NULL;
 574                 for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 575                         /* replace an entry? */
 576                         if(iter->namespc == namespc) {
 577                                 if(iter_last == NULL) {
 578                                         symbol->declaration = declaration;
 579                                 } else {
 580                                         iter_last->symbol_next = declaration;
 581                                 }
 582                                 declaration->symbol_next = iter->symbol_next;
 583                                 break;
 584                         }
 585                 }
 586                 if(iter == NULL) {
 587                         assert(iter_last->symbol_next == NULL);
 588                         iter_last->symbol_next = declaration;
 589                 }
 590         }
 591
 592         /* remember old declaration */
 593         stack_entry_t entry;
 594         entry.symbol          = symbol;
 595         entry.old_declaration = iter;
 596         entry.namespc         = (unsigned short) namespc;
 597         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 598 }
 599
 600 static void environment_push(declaration_t *declaration)
 601 {
 602         assert(declaration->source_position.input_name != NULL);
 603         assert(declaration->parent_scope != NULL);
 604         stack_push(&environment_stack, declaration);
 605 }
 606
 607 static void label_push(declaration_t *declaration)
 608 {
 609         declaration->parent_scope = &current_function->scope;
 610         stack_push(&label_stack, declaration);
 611 }
 612
 613 /**
 614  * pops symbols from the environment stack until @p new_top is the top element
 615  */
 616 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 617 {
 618         stack_entry_t *stack = *stack_ptr;
 619         size_t         top   = ARR_LEN(stack);
 620         size_t         i;
 621
 622         assert(new_top <= top);
 623         if(new_top == top)
 624                 return;
 625
 626         for(i = top; i > new_top; --i) {
 627                 stack_entry_t *entry = &stack[i - 1];
 628
 629                 declaration_t *old_declaration = entry->old_declaration;
 630                 symbol_t      *symbol          = entry->symbol;
 631                 namespace_t    namespc         = (namespace_t)entry->namespc;
 632
 633                 /* replace/remove declaration */
 634                 declaration_t *declaration = symbol->declaration;
 635                 assert(declaration != NULL);
 636                 if(declaration->namespc == namespc) {
 637                         if(old_declaration == NULL) {
 638                                 symbol->declaration = declaration->symbol_next;
 639                         } else {
 640                                 symbol->declaration = old_declaration;
 641                         }
 642                 } else {
 643                         declaration_t *iter_last = declaration;
 644                         declaration_t *iter      = declaration->symbol_next;
 645                         for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 646                                 /* replace an entry? */
 647                                 if(iter->namespc == namespc) {
 648                                         assert(iter_last != NULL);
 649                                         iter_last->symbol_next = old_declaration;
 650                                         if(old_declaration != NULL) {
 651                                                 old_declaration->symbol_next = iter->symbol_next;
 652                                         }
 653                                         break;
 654                                 }
 655                         }
 656                         assert(iter != NULL);
 657                 }
 658         }
 659
 660         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 661 }
 662
 663 static void environment_pop_to(size_t new_top)
 664 {
 665         stack_pop_to(&environment_stack, new_top);
 666 }
 667
 668 static void label_pop_to(size_t new_top)
 669 {
 670         stack_pop_to(&label_stack, new_top);
 671 }
 672
 673
 674 static int get_rank(const type_t *type)
 675 {
 676         assert(!is_typeref(type));
 677         /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
 678          * and esp. footnote 108). However we can't fold constants (yet), so we
 679          * can't decide whether unsigned int is possible, while int always works.
 680          * (unsigned int would be preferable when possible... for stuff like
 681          *  struct { enum { ... } bla : 4; } ) */
 682         if(type->kind == TYPE_ENUM)
 683                 return ATOMIC_TYPE_INT;
 684
 685         assert(type->kind == TYPE_ATOMIC);
 686         return type->atomic.akind;
 687 }
 688
 689 static type_t *promote_integer(type_t *type)
 690 {
 691         if(type->kind == TYPE_BITFIELD)
 692                 type = type->bitfield.base;
 693
 694         if(get_rank(type) < ATOMIC_TYPE_INT)
 695                 type = type_int;
 696
 697         return type;
 698 }
 699
 700 /**
 701  * Create a cast expression.
 702  *
 703  * @param expression  the expression to cast
 704  * @param dest_type   the destination type
 705  */
 706 static expression_t *create_cast_expression(expression_t *expression,
 707                                             type_t *dest_type)
 708 {
 709         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 710
 711         cast->unary.value = expression;
 712         cast->base.type   = dest_type;
 713
 714         return cast;
 715 }
 716
 717 /**
 718  * Check if a given expression represents the 0 pointer constant.
 719  */
 720 static bool is_null_pointer_constant(const expression_t *expression)
 721 {
 722         /* skip void* cast */
 723         if(expression->kind == EXPR_UNARY_CAST
 724                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 725                 expression = expression->unary.value;
 726         }
 727
 728         /* TODO: not correct yet, should be any constant integer expression
 729          * which evaluates to 0 */
 730         if (expression->kind != EXPR_CONST)
 731                 return false;
 732
 733         type_t *const type = skip_typeref(expression->base.type);
 734         if (!is_type_integer(type))
 735                 return false;
 736
 737         return expression->conste.v.int_value == 0;
 738 }
 739
 740 /**
 741  * Create an implicit cast expression.
 742  *
 743  * @param expression  the expression to cast
 744  * @param dest_type   the destination type
 745  */
 746 static expression_t *create_implicit_cast(expression_t *expression,
 747                                           type_t *dest_type)
 748 {
 749         type_t *const source_type = expression->base.type;
 750
 751         if (source_type == dest_type)
 752                 return expression;
 753
 754         return create_cast_expression(expression, dest_type);
 755 }
 756
 757 /** Implements the rules from § 6.5.16.1 */
 758 static type_t *semantic_assign(type_t *orig_type_left,
 759                             const expression_t *const right,
 760                             const char *context)
 761 {
 762         type_t *const orig_type_right = right->base.type;
 763         type_t *const type_left       = skip_typeref(orig_type_left);
 764         type_t *const type_right      = skip_typeref(orig_type_right);
 765
 766         if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 767             (is_type_pointer(type_left) && is_null_pointer_constant(right)) ||
 768             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 769                 && is_type_pointer(type_right))) {
 770                 return orig_type_left;
 771         }
 772
 773         if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
 774                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 775                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 776
 777                 /* the left type has all qualifiers from the right type */
 778                 unsigned missing_qualifiers
 779                         = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 780                 if(missing_qualifiers != 0) {
 781                         errorf(HERE, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointed-to type", type_left, context, type_right, missing_qualifiers);
 782                         return orig_type_left;
 783                 }
 784
 785                 points_to_left  = get_unqualified_type(points_to_left);
 786                 points_to_right = get_unqualified_type(points_to_right);
 787
 788                 if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID) ||
 789                                 is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
 790                         return orig_type_left;
 791                 }
 792
 793                 if (!types_compatible(points_to_left, points_to_right)) {
 794                         warningf(right->base.source_position,
 795                                 "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 796                                 orig_type_left, context, right, orig_type_right);
 797                 }
 798
 799                 return orig_type_left;
 800         }
 801
 802         if ((is_type_compound(type_left)  && is_type_compound(type_right))
 803                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
 804                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
 805                 type_t *const unqual_type_right = get_unqualified_type(type_right);
 806                 if (types_compatible(unqual_type_left, unqual_type_right)) {
 807                         return orig_type_left;
 808                 }
 809         }
 810
 811         if (!is_type_valid(type_left))
 812                 return type_left;
 813
 814         if (!is_type_valid(type_right))
 815                 return orig_type_right;
 816
 817         return NULL;
 818 }
 819
 820 static expression_t *parse_constant_expression(void)
 821 {
 822         /* start parsing at precedence 7 (conditional expression) */
 823         expression_t *result = parse_sub_expression(7);
 824
 825         if(!is_constant_expression(result)) {
 826                 errorf(result->base.source_position, "expression '%E' is not constant\n", result);
 827         }
 828
 829         return result;
 830 }
 831
 832 static expression_t *parse_assignment_expression(void)
 833 {
 834         /* start parsing at precedence 2 (assignment expression) */
 835         return parse_sub_expression(2);
 836 }
 837
 838 static type_t *make_global_typedef(const char *name, type_t *type)
 839 {
 840         symbol_t *const symbol       = symbol_table_insert(name);
 841
 842         declaration_t *const declaration = allocate_declaration_zero();
 843         declaration->namespc                = NAMESPACE_NORMAL;
 844         declaration->storage_class          = STORAGE_CLASS_TYPEDEF;
 845         declaration->declared_storage_class = STORAGE_CLASS_TYPEDEF;
 846         declaration->type                   = type;
 847         declaration->symbol                 = symbol;
 848         declaration->source_position        = builtin_source_position;
 849
 850         record_declaration(declaration);
 851
 852         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF, builtin_source_position);
 853         typedef_type->typedeft.declaration = declaration;
 854
 855         return typedef_type;
 856 }
 857
 858 static string_t parse_string_literals(void)
 859 {
 860         assert(token.type == T_STRING_LITERAL);
 861         string_t result = token.v.string;
 862
 863         next_token();
 864
 865         while (token.type == T_STRING_LITERAL) {
 866                 result = concat_strings(&result, &token.v.string);
 867                 next_token();
 868         }
 869
 870         return result;
 871 }
 872
 873 static void parse_attributes(void)
 874 {
 875         while(true) {
 876                 switch(token.type) {
 877                 case T___attribute__: {
 878                         next_token();
 879
 880                         expect('(');
 881                         int depth = 1;
 882                         while(depth > 0) {
 883                                 switch(token.type) {
 884                                 case T_EOF:
 885                                         errorf(HERE, "EOF while parsing attribute");
 886                                         break;
 887                                 case '(':
 888                                         next_token();
 889                                         depth++;
 890                                         break;
 891                                 case ')':
 892                                         next_token();
 893                                         depth--;
 894                                         break;
 895                                 default:
 896                                         next_token();
 897                                 }
 898                         }
 899                         break;
 900                 }
 901                 case T_asm:
 902                         next_token();
 903                         expect('(');
 904                         if(token.type != T_STRING_LITERAL) {
 905                                 parse_error_expected("while parsing assembler attribute",
 906                                                      T_STRING_LITERAL);
 907                                 eat_paren();
 908                                 break;
 909                         } else {
 910                                 parse_string_literals();
 911                         }
 912                         expect(')');
 913                         break;
 914                 default:
 915                         goto attributes_finished;
 916                 }
 917         }
 918
 919 end_error:
 920 attributes_finished:
 921         ;
 922 }
 923
 924 static designator_t *parse_designation(void)
 925 {
 926         designator_t *result = NULL;
 927         designator_t *last   = NULL;
 928
 929         while(true) {
 930                 designator_t *designator;
 931                 switch(token.type) {
 932                 case '[':
 933                         designator = allocate_ast_zero(sizeof(designator[0]));
 934                         designator->source_position = token.source_position;
 935                         next_token();
 936                         designator->array_index = parse_constant_expression();
 937                         expect(']');
 938                         break;
 939                 case '.':
 940                         designator = allocate_ast_zero(sizeof(designator[0]));
 941                         designator->source_position = token.source_position;
 942                         next_token();
 943                         if(token.type != T_IDENTIFIER) {
 944                                 parse_error_expected("while parsing designator",
 945                                                      T_IDENTIFIER, 0);
 946                                 return NULL;
 947                         }
 948                         designator->symbol = token.v.symbol;
 949                         next_token();
 950                         break;
 951                 default:
 952                         expect('=');
 953                         return result;
 954                 }
 955
 956                 assert(designator != NULL);
 957                 if(last != NULL) {
 958                         last->next = designator;
 959                 } else {
 960                         result = designator;
 961                 }
 962                 last = designator;
 963         }
 964 end_error:
 965         return NULL;
 966 }
 967
 968 static initializer_t *initializer_from_string(array_type_t *type,
 969                                               const string_t *const string)
 970 {
 971         /* TODO: check len vs. size of array type */
 972         (void) type;
 973
 974         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
 975         initializer->string.string = *string;
 976
 977         return initializer;
 978 }
 979
 980 static initializer_t *initializer_from_wide_string(array_type_t *const type,
 981                                                    wide_string_t *const string)
 982 {
 983         /* TODO: check len vs. size of array type */
 984         (void) type;
 985
 986         initializer_t *const initializer =
 987                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
 988         initializer->wide_string.string = *string;
 989
 990         return initializer;
 991 }
 992
 993 /**
 994  * Build an initializer from a given expression.
 995  */
 996 static initializer_t *initializer_from_expression(type_t *orig_type,
 997                                                   expression_t *expression)
 998 {
 999         /* TODO check that expression is a constant expression */
1000
1001         /* § 6.7.8.14/15 char array may be initialized by string literals */
1002         type_t *type           = skip_typeref(orig_type);
1003         type_t *expr_type_orig = expression->base.type;
1004         type_t *expr_type      = skip_typeref(expr_type_orig);
1005         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1006                 array_type_t *const array_type   = &type->array;
1007                 type_t       *const element_type = skip_typeref(array_type->element_type);
1008
1009                 if (element_type->kind == TYPE_ATOMIC) {
1010                         atomic_type_kind_t akind = element_type->atomic.akind;
1011                         switch (expression->kind) {
1012                                 case EXPR_STRING_LITERAL:
1013                                         if (akind == ATOMIC_TYPE_CHAR
1014                                                         || akind == ATOMIC_TYPE_SCHAR
1015                                                         || akind == ATOMIC_TYPE_UCHAR) {
1016                                                 return initializer_from_string(array_type,
1017                                                         &expression->string.value);
1018                                         }
1019
1020                                 case EXPR_WIDE_STRING_LITERAL: {
1021                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1022                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1023                                                 return initializer_from_wide_string(array_type,
1024                                                         &expression->wide_string.value);
1025                                         }
1026                                 }
1027
1028                                 default:
1029                                         break;
1030                         }
1031                 }
1032         }
1033
1034         type_t *const res_type = semantic_assign(type, expression, "initializer");
1035         if (res_type == NULL)
1036                 return NULL;
1037
1038         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1039         result->value.value = create_implicit_cast(expression, res_type);
1040
1041         return result;
1042 }
1043
1044 /**
1045  * Checks if a given expression can be used as an constant initializer.
1046  */
1047 static bool is_initializer_constant(const expression_t *expression)
1048 {
1049         return is_constant_expression(expression)
1050                 || is_address_constant(expression);
1051 }
1052
1053 /**
1054  * Parses an scalar initializer.
1055  *
1056  * § 6.7.8.11; eat {} without warning
1057  */
1058 static initializer_t *parse_scalar_initializer(type_t *type,
1059                                                bool must_be_constant)
1060 {
1061         /* there might be extra {} hierarchies */
1062         int braces = 0;
1063         while(token.type == '{') {
1064                 next_token();
1065                 if(braces == 0) {
1066                         warningf(HERE, "extra curly braces around scalar initializer");
1067                 }
1068                 braces++;
1069         }
1070
1071         expression_t *expression = parse_assignment_expression();
1072         if(must_be_constant && !is_initializer_constant(expression)) {
1073                 errorf(expression->base.source_position,
1074                        "Initialisation expression '%E' is not constant\n",
1075                        expression);
1076         }
1077
1078         initializer_t *initializer = initializer_from_expression(type, expression);
1079
1080         if(initializer == NULL) {
1081                 errorf(expression->base.source_position,
1082                        "expression '%E' doesn't match expected type '%T'",
1083                        expression, type);
1084                 /* TODO */
1085                 return NULL;
1086         }
1087
1088         bool additional_warning_displayed = false;
1089         while(braces > 0) {
1090                 if(token.type == ',') {
1091                         next_token();
1092                 }
1093                 if(token.type != '}') {
1094                         if(!additional_warning_displayed) {
1095                                 warningf(HERE, "additional elements in scalar initializer");
1096                                 additional_warning_displayed = true;
1097                         }
1098                 }
1099                 eat_block();
1100                 braces--;
1101         }
1102
1103         return initializer;
1104 }
1105
1106 /**
1107  * An entry in the type path.
1108  */
1109 typedef struct type_path_entry_t type_path_entry_t;
1110 struct type_path_entry_t {
1111         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1112         union {
1113                 size_t         index;          /**< For array types: the current index. */
1114                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1115         } v;
1116 };
1117
1118 /**
1119  * A type path expression a position inside compound or array types.
1120  */
1121 typedef struct type_path_t type_path_t;
1122 struct type_path_t {
1123         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1124         type_t            *top_type;     /**< type of the element the path points */
1125         size_t             max_index;    /**< largest index in outermost array */
1126 };
1127
1128 /**
1129  * Prints a type path for debugging.
1130  */
1131 static __attribute__((unused)) void debug_print_type_path(
1132                 const type_path_t *path)
1133 {
1134         size_t len = ARR_LEN(path->path);
1135
1136         for(size_t i = 0; i < len; ++i) {
1137                 const type_path_entry_t *entry = & path->path[i];
1138
1139                 type_t *type = skip_typeref(entry->type);
1140                 if(is_type_compound(type)) {
1141                         /* in gcc mode structs can have no members */
1142                         if(entry->v.compound_entry == NULL) {
1143                                 assert(i == len-1);
1144                                 continue;
1145                         }
1146                         fprintf(stderr, ".%s", entry->v.compound_entry->symbol->string);
1147                 } else if(is_type_array(type)) {
1148                         fprintf(stderr, "[%u]", entry->v.index);
1149                 } else {
1150                         fprintf(stderr, "-INVALID-");
1151                 }
1152         }
1153         if(path->top_type != NULL) {
1154                 fprintf(stderr, "  (");
1155                 print_type(path->top_type);
1156                 fprintf(stderr, ")");
1157         }
1158 }
1159
1160 /**
1161  * Return the top type path entry, ie. in a path
1162  * (type).a.b returns the b.
1163  */
1164 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1165 {
1166         size_t len = ARR_LEN(path->path);
1167         assert(len > 0);
1168         return &path->path[len-1];
1169 }
1170
1171 /**
1172  * Enlarge the type path by an (empty) element.
1173  */
1174 static type_path_entry_t *append_to_type_path(type_path_t *path)
1175 {
1176         size_t len = ARR_LEN(path->path);
1177         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1178
1179         type_path_entry_t *result = & path->path[len];
1180         memset(result, 0, sizeof(result[0]));
1181         return result;
1182 }
1183
1184 /**
1185  * Descending into a sub-type. Enter the scope of the current
1186  * top_type.
1187  */
1188 static void descend_into_subtype(type_path_t *path)
1189 {
1190         type_t *orig_top_type = path->top_type;
1191         type_t *top_type      = skip_typeref(orig_top_type);
1192
1193         assert(is_type_compound(top_type) || is_type_array(top_type));
1194
1195         type_path_entry_t *top = append_to_type_path(path);
1196         top->type              = top_type;
1197
1198         if(is_type_compound(top_type)) {
1199                 declaration_t *declaration = top_type->compound.declaration;
1200                 declaration_t *entry       = declaration->scope.declarations;
1201                 top->v.compound_entry      = entry;
1202
1203                 if(entry != NULL) {
1204                         path->top_type         = entry->type;
1205                 } else {
1206                         path->top_type         = NULL;
1207                 }
1208         } else {
1209                 assert(is_type_array(top_type));
1210
1211                 top->v.index   = 0;
1212                 path->top_type = top_type->array.element_type;
1213         }
1214 }
1215
1216 /**
1217  * Pop an entry from the given type path, ie. returning from
1218  * (type).a.b to (type).a
1219  */
1220 static void ascend_from_subtype(type_path_t *path)
1221 {
1222         type_path_entry_t *top = get_type_path_top(path);
1223
1224         path->top_type = top->type;
1225
1226         size_t len = ARR_LEN(path->path);
1227         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1228 }
1229
1230 /**
1231  * Pop entries from the given type path until the given
1232  * path level is reached.
1233  */
1234 static void ascend_to(type_path_t *path, size_t top_path_level)
1235 {
1236         size_t len = ARR_LEN(path->path);
1237
1238         while(len > top_path_level) {
1239                 ascend_from_subtype(path);
1240                 len = ARR_LEN(path->path);
1241         }
1242 }
1243
1244 static bool walk_designator(type_path_t *path, const designator_t *designator,
1245                             bool used_in_offsetof)
1246 {
1247         for( ; designator != NULL; designator = designator->next) {
1248                 type_path_entry_t *top       = get_type_path_top(path);
1249                 type_t            *orig_type = top->type;
1250
1251                 type_t *type = skip_typeref(orig_type);
1252
1253                 if(designator->symbol != NULL) {
1254                         symbol_t *symbol = designator->symbol;
1255                         if(!is_type_compound(type)) {
1256                                 if(is_type_valid(type)) {
1257                                         errorf(designator->source_position,
1258                                                "'.%Y' designator used for non-compound type '%T'",
1259                                                symbol, orig_type);
1260                                 }
1261                                 goto failed;
1262                         }
1263
1264                         declaration_t *declaration = type->compound.declaration;
1265                         declaration_t *iter        = declaration->scope.declarations;
1266                         for( ; iter != NULL; iter = iter->next) {
1267                                 if(iter->symbol == symbol) {
1268                                         break;
1269                                 }
1270                         }
1271                         if(iter == NULL) {
1272                                 errorf(designator->source_position,
1273                                        "'%T' has no member named '%Y'", orig_type, symbol);
1274                                 goto failed;
1275                         }
1276                         if(used_in_offsetof) {
1277                                 type_t *real_type = skip_typeref(iter->type);
1278                                 if(real_type->kind == TYPE_BITFIELD) {
1279                                         errorf(designator->source_position,
1280                                                "offsetof designator '%Y' may not specify bitfield",
1281                                                symbol);
1282                                         goto failed;
1283                                 }
1284                         }
1285
1286                         top->type             = orig_type;
1287                         top->v.compound_entry = iter;
1288                         orig_type             = iter->type;
1289                 } else {
1290                         expression_t *array_index = designator->array_index;
1291                         assert(designator->array_index != NULL);
1292
1293                         if(!is_type_array(type)) {
1294                                 if(is_type_valid(type)) {
1295                                         errorf(designator->source_position,
1296                                                "[%E] designator used for non-array type '%T'",
1297                                                array_index, orig_type);
1298                                 }
1299                                 goto failed;
1300                         }
1301                         if(!is_type_valid(array_index->base.type)) {
1302                                 goto failed;
1303                         }
1304
1305                         long index = fold_constant(array_index);
1306                         if(!used_in_offsetof) {
1307                                 if(index < 0) {
1308                                         errorf(designator->source_position,
1309                                                "array index [%E] must be positive", array_index);
1310                                         goto failed;
1311                                 }
1312                                 if(type->array.size_constant == true) {
1313                                         long array_size = type->array.size;
1314                                         if(index >= array_size) {
1315                                                 errorf(designator->source_position,
1316                                                                 "designator [%E] (%d) exceeds array size %d",
1317                                                                 array_index, index, array_size);
1318                                                 goto failed;
1319                                         }
1320                                 }
1321                         }
1322
1323                         top->type    = orig_type;
1324                         top->v.index = (size_t) index;
1325                         orig_type    = type->array.element_type;
1326                 }
1327                 path->top_type = orig_type;
1328
1329                 if(designator->next != NULL) {
1330                         descend_into_subtype(path);
1331                 }
1332         }
1333         return true;
1334
1335 failed:
1336         return false;
1337 }
1338
1339 static void advance_current_object(type_path_t *path, size_t top_path_level)
1340 {
1341         type_path_entry_t *top = get_type_path_top(path);
1342
1343         type_t *type = skip_typeref(top->type);
1344         if(is_type_union(type)) {
1345                 /* in unions only the first element is initialized */
1346                 top->v.compound_entry = NULL;
1347         } else if(is_type_struct(type)) {
1348                 declaration_t *entry = top->v.compound_entry;
1349
1350                 entry                 = entry->next;
1351                 top->v.compound_entry = entry;
1352                 if(entry != NULL) {
1353                         path->top_type = entry->type;
1354                         return;
1355                 }
1356         } else {
1357                 assert(is_type_array(type));
1358
1359                 top->v.index++;
1360
1361                 if(!type->array.size_constant || top->v.index < type->array.size) {
1362                         return;
1363                 }
1364         }
1365
1366         /* we're past the last member of the current sub-aggregate, try if we
1367          * can ascend in the type hierarchy and continue with another subobject */
1368         size_t len = ARR_LEN(path->path);
1369
1370         if(len > top_path_level) {
1371                 ascend_from_subtype(path);
1372                 advance_current_object(path, top_path_level);
1373         } else {
1374                 path->top_type = NULL;
1375         }
1376 }
1377
1378 /**
1379  * skip any {...} blocks until a closing braket is reached.
1380  */
1381 static void skip_initializers(void)
1382 {
1383         if(token.type == '{')
1384                 next_token();
1385
1386         while(token.type != '}') {
1387                 if(token.type == T_EOF)
1388                         return;
1389                 if(token.type == '{') {
1390                         eat_block();
1391                         continue;
1392                 }
1393                 next_token();
1394         }
1395 }
1396
1397 /**
1398  * Parse a part of an initialiser for a struct or union,
1399  */
1400 static initializer_t *parse_sub_initializer(type_path_t *path,
1401                 type_t *outer_type, size_t top_path_level,
1402                 parse_initializer_env_t *env)
1403 {
1404         if(token.type == '}') {
1405                 /* empty initializer */
1406                 return NULL;
1407         }
1408
1409         type_t *orig_type = path->top_type;
1410         type_t *type      = NULL;
1411
1412         if (orig_type == NULL) {
1413                 /* We are initializing an empty compound. */
1414         } else {
1415                 type = skip_typeref(orig_type);
1416
1417                 /* we can't do usefull stuff if we didn't even parse the type. Skip the
1418                  * initializers in this case. */
1419                 if(!is_type_valid(type)) {
1420                         skip_initializers();
1421                         return NULL;
1422                 }
1423         }
1424
1425         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1426
1427         while(true) {
1428                 designator_t *designator = NULL;
1429                 if(token.type == '.' || token.type == '[') {
1430                         designator = parse_designation();
1431
1432                         /* reset path to toplevel, evaluate designator from there */
1433                         ascend_to(path, top_path_level);
1434                         if(!walk_designator(path, designator, false)) {
1435                                 /* can't continue after designation error */
1436                                 goto end_error;
1437                         }
1438
1439                         initializer_t *designator_initializer
1440                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1441                         designator_initializer->designator.designator = designator;
1442                         ARR_APP1(initializer_t*, initializers, designator_initializer);
1443                 }
1444
1445                 initializer_t *sub;
1446
1447                 if(token.type == '{') {
1448                         if(type != NULL && is_type_scalar(type)) {
1449                                 sub = parse_scalar_initializer(type, env->must_be_constant);
1450                         } else {
1451                                 eat('{');
1452                                 if(type == NULL) {
1453                                         if (env->declaration != NULL)
1454                                                 errorf(HERE, "extra brace group at end of initializer for '%Y'",
1455                                                 env->declaration->symbol);
1456                                 else
1457                                                 errorf(HERE, "extra brace group at end of initializer");
1458                                 } else
1459                                         descend_into_subtype(path);
1460
1461                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
1462                                                             env);
1463
1464                                 if(type != NULL) {
1465                                         ascend_from_subtype(path);
1466                                         expect_block('}');
1467                                 } else {
1468                                         expect_block('}');
1469                                         goto error_parse_next;
1470                                 }
1471                         }
1472                 } else {
1473                         /* must be an expression */
1474                         expression_t *expression = parse_assignment_expression();
1475
1476                         if(env->must_be_constant && !is_initializer_constant(expression)) {
1477                                 errorf(expression->base.source_position,
1478                                        "Initialisation expression '%E' is not constant\n",
1479                                        expression);
1480                         }
1481
1482                         if(type == NULL) {
1483                                 /* we are already outside, ... */
1484                                 goto error_excess;
1485                         }
1486
1487                         /* handle { "string" } special case */
1488                         if((expression->kind == EXPR_STRING_LITERAL
1489                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
1490                                         && outer_type != NULL) {
1491                                 sub = initializer_from_expression(outer_type, expression);
1492                                 if(sub != NULL) {
1493                                         if(token.type == ',') {
1494                                                 next_token();
1495                                         }
1496                                         if(token.type != '}') {
1497                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
1498                                                                  orig_type);
1499                                         }
1500                                         /* TODO: eat , ... */
1501                                         return sub;
1502                                 }
1503                         }
1504
1505                         /* descend into subtypes until expression matches type */
1506                         while(true) {
1507                                 orig_type = path->top_type;
1508                                 type      = skip_typeref(orig_type);
1509
1510                                 sub = initializer_from_expression(orig_type, expression);
1511                                 if(sub != NULL) {
1512                                         break;
1513                                 }
1514                                 if(!is_type_valid(type)) {
1515                                         goto end_error;
1516                                 }
1517                                 if(is_type_scalar(type)) {
1518                                         errorf(expression->base.source_position,
1519                                                         "expression '%E' doesn't match expected type '%T'",
1520                                                         expression, orig_type);
1521                                         goto end_error;
1522                                 }
1523
1524                                 descend_into_subtype(path);
1525                         }
1526                 }
1527
1528                 /* update largest index of top array */
1529                 const type_path_entry_t *first      = &path->path[0];
1530                 type_t                  *first_type = first->type;
1531                 first_type                          = skip_typeref(first_type);
1532                 if(is_type_array(first_type)) {
1533                         size_t index = first->v.index;
1534                         if(index > path->max_index)
1535                                 path->max_index = index;
1536                 }
1537
1538                 if(type != NULL) {
1539                         /* append to initializers list */
1540                         ARR_APP1(initializer_t*, initializers, sub);
1541                 } else {
1542 error_excess:
1543                         if(env->declaration != NULL)
1544                                 warningf(HERE, "excess elements in struct initializer for '%Y'",
1545                                  env->declaration->symbol);
1546                         else
1547                                 warningf(HERE, "excess elements in struct initializer");
1548                 }
1549
1550 error_parse_next:
1551                 if(token.type == '}') {
1552                         break;
1553                 }
1554                 expect(',');
1555                 if(token.type == '}') {
1556                         break;
1557                 }
1558
1559                 if(type != NULL) {
1560                         /* advance to the next declaration if we are not at the end */
1561                         advance_current_object(path, top_path_level);
1562                         orig_type = path->top_type;
1563                         if(orig_type != NULL)
1564                                 type = skip_typeref(orig_type);
1565                         else
1566                                 type = NULL;
1567                 }
1568         }
1569
1570         size_t len  = ARR_LEN(initializers);
1571         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
1572         initializer_t *result = allocate_ast_zero(size);
1573         result->kind          = INITIALIZER_LIST;
1574         result->list.len      = len;
1575         memcpy(&result->list.initializers, initializers,
1576                len * sizeof(initializers[0]));
1577
1578         DEL_ARR_F(initializers);
1579         ascend_to(path, top_path_level);
1580
1581         return result;
1582
1583 end_error:
1584         skip_initializers();
1585         DEL_ARR_F(initializers);
1586         ascend_to(path, top_path_level);
1587         return NULL;
1588 }
1589
1590 /**
1591  * Parses an initializer. Parsers either a compound literal
1592  * (env->declaration == NULL) or an initializer of a declaration.
1593  */
1594 static initializer_t *parse_initializer(parse_initializer_env_t *env)
1595 {
1596         type_t        *type   = skip_typeref(env->type);
1597         initializer_t *result = NULL;
1598         size_t         max_index;
1599
1600         if(is_type_scalar(type)) {
1601                 result = parse_scalar_initializer(type, env->must_be_constant);
1602         } else if(token.type == '{') {
1603                 eat('{');
1604
1605                 type_path_t path;
1606                 memset(&path, 0, sizeof(path));
1607                 path.top_type = env->type;
1608                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
1609
1610                 descend_into_subtype(&path);
1611
1612                 result = parse_sub_initializer(&path, env->type, 1, env);
1613
1614                 max_index = path.max_index;
1615                 DEL_ARR_F(path.path);
1616
1617                 expect('}');
1618         } else {
1619                 /* parse_scalar_initializer() also works in this case: we simply
1620                  * have an expression without {} around it */
1621                 result = parse_scalar_initializer(type, env->must_be_constant);
1622         }
1623
1624         /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
1625          * the array type size */
1626         if(is_type_array(type) && type->array.size_expression == NULL
1627                         && result != NULL) {
1628                 size_t size;
1629                 switch (result->kind) {
1630                 case INITIALIZER_LIST:
1631                         size = max_index + 1;
1632                         break;
1633
1634                 case INITIALIZER_STRING:
1635                         size = result->string.string.size;
1636                         break;
1637
1638                 case INITIALIZER_WIDE_STRING:
1639                         size = result->wide_string.string.size;
1640                         break;
1641
1642                 default:
1643                         panic("invalid initializer type");
1644                 }
1645
1646                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
1647                 cnst->base.type          = type_size_t;
1648                 cnst->conste.v.int_value = size;
1649
1650                 type_t *new_type = duplicate_type(type);
1651
1652                 new_type->array.size_expression = cnst;
1653                 new_type->array.size_constant   = true;
1654                 new_type->array.size            = size;
1655                 env->type = new_type;
1656         }
1657
1658         return result;
1659 end_error:
1660         return NULL;
1661 }
1662
1663 static declaration_t *append_declaration(declaration_t *declaration);
1664
1665 static declaration_t *parse_compound_type_specifier(bool is_struct)
1666 {
1667         if(is_struct) {
1668                 eat(T_struct);
1669         } else {
1670                 eat(T_union);
1671         }
1672
1673         symbol_t      *symbol      = NULL;
1674         declaration_t *declaration = NULL;
1675
1676         if (token.type == T___attribute__) {
1677                 /* TODO */
1678                 parse_attributes();
1679         }
1680
1681         if(token.type == T_IDENTIFIER) {
1682                 symbol = token.v.symbol;
1683                 next_token();
1684
1685                 if(is_struct) {
1686                         declaration = get_declaration(symbol, NAMESPACE_STRUCT);
1687                 } else {
1688                         declaration = get_declaration(symbol, NAMESPACE_UNION);
1689                 }
1690         } else if(token.type != '{') {
1691                 if(is_struct) {
1692                         parse_error_expected("while parsing struct type specifier",
1693                                              T_IDENTIFIER, '{', 0);
1694                 } else {
1695                         parse_error_expected("while parsing union type specifier",
1696                                              T_IDENTIFIER, '{', 0);
1697                 }
1698
1699                 return NULL;
1700         }
1701
1702         if(declaration == NULL) {
1703                 declaration = allocate_declaration_zero();
1704                 declaration->namespc         =
1705                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
1706                 declaration->source_position = token.source_position;
1707                 declaration->symbol          = symbol;
1708                 declaration->parent_scope  = scope;
1709                 if (symbol != NULL) {
1710                         environment_push(declaration);
1711                 }
1712                 append_declaration(declaration);
1713         }
1714
1715         if(token.type == '{') {
1716                 if(declaration->init.is_defined) {
1717                         assert(symbol != NULL);
1718                         errorf(HERE, "multiple definitions of '%s %Y'",
1719                                is_struct ? "struct" : "union", symbol);
1720                         declaration->scope.declarations = NULL;
1721                 }
1722                 declaration->init.is_defined = true;
1723
1724                 parse_compound_type_entries(declaration);
1725                 parse_attributes();
1726         }
1727
1728         return declaration;
1729 }
1730
1731 static void parse_enum_entries(type_t *const enum_type)
1732 {
1733         eat('{');
1734
1735         if(token.type == '}') {
1736                 next_token();
1737                 errorf(HERE, "empty enum not allowed");
1738                 return;
1739         }
1740
1741         do {
1742                 if(token.type != T_IDENTIFIER) {
1743                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, 0);
1744                         eat_block();
1745                         return;
1746                 }
1747
1748                 declaration_t *const entry = allocate_declaration_zero();
1749                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
1750                 entry->type            = enum_type;
1751                 entry->symbol          = token.v.symbol;
1752                 entry->source_position = token.source_position;
1753                 next_token();
1754
1755                 if(token.type == '=') {
1756                         next_token();
1757                         expression_t *value = parse_constant_expression();
1758
1759                         value = create_implicit_cast(value, enum_type);
1760                         entry->init.enum_value = value;
1761
1762                         /* TODO semantic */
1763                 }
1764
1765                 record_declaration(entry);
1766
1767                 if(token.type != ',')
1768                         break;
1769                 next_token();
1770         } while(token.type != '}');
1771
1772         expect('}');
1773
1774 end_error:
1775         ;
1776 }
1777
1778 static type_t *parse_enum_specifier(void)
1779 {
1780         eat(T_enum);
1781
1782         declaration_t *declaration;
1783         symbol_t      *symbol;
1784
1785         if(token.type == T_IDENTIFIER) {
1786                 symbol = token.v.symbol;
1787                 next_token();
1788
1789                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1790         } else if(token.type != '{') {
1791                 parse_error_expected("while parsing enum type specifier",
1792                                      T_IDENTIFIER, '{', 0);
1793                 return NULL;
1794         } else {
1795                 declaration = NULL;
1796                 symbol      = NULL;
1797         }
1798
1799         if(declaration == NULL) {
1800                 declaration = allocate_declaration_zero();
1801                 declaration->namespc         = NAMESPACE_ENUM;
1802                 declaration->source_position = token.source_position;
1803                 declaration->symbol          = symbol;
1804                 declaration->parent_scope  = scope;
1805         }
1806
1807         type_t *const type      = allocate_type_zero(TYPE_ENUM, declaration->source_position);
1808         type->enumt.declaration = declaration;
1809
1810         if(token.type == '{') {
1811                 if(declaration->init.is_defined) {
1812                         errorf(HERE, "multiple definitions of enum %Y", symbol);
1813                 }
1814                 if (symbol != NULL) {
1815                         environment_push(declaration);
1816                 }
1817                 append_declaration(declaration);
1818                 declaration->init.is_defined = 1;
1819
1820                 parse_enum_entries(type);
1821                 parse_attributes();
1822         }
1823
1824         return type;
1825 }
1826
1827 /**
1828  * if a symbol is a typedef to another type, return true
1829  */
1830 static bool is_typedef_symbol(symbol_t *symbol)
1831 {
1832         const declaration_t *const declaration =
1833                 get_declaration(symbol, NAMESPACE_NORMAL);
1834         return
1835                 declaration != NULL &&
1836                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1837 }
1838
1839 static type_t *parse_typeof(void)
1840 {
1841         eat(T___typeof__);
1842
1843         type_t *type;
1844
1845         expect('(');
1846
1847         expression_t *expression  = NULL;
1848
1849 restart:
1850         switch(token.type) {
1851         case T___extension__:
1852                 /* this can be a prefix to a typename or an expression */
1853                 /* we simply eat it now. */
1854                 do {
1855                         next_token();
1856                 } while(token.type == T___extension__);
1857                 goto restart;
1858
1859         case T_IDENTIFIER:
1860                 if(is_typedef_symbol(token.v.symbol)) {
1861                         type = parse_typename();
1862                 } else {
1863                         expression = parse_expression();
1864                         type       = expression->base.type;
1865                 }
1866                 break;
1867
1868         TYPENAME_START
1869                 type = parse_typename();
1870                 break;
1871
1872         default:
1873                 expression = parse_expression();
1874                 type       = expression->base.type;
1875                 break;
1876         }
1877
1878         expect(')');
1879
1880         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF, expression->base.source_position);
1881         typeof_type->typeoft.expression  = expression;
1882         typeof_type->typeoft.typeof_type = type;
1883
1884         return typeof_type;
1885 end_error:
1886         return NULL;
1887 }
1888
1889 typedef enum {
1890         SPECIFIER_SIGNED    = 1 << 0,
1891         SPECIFIER_UNSIGNED  = 1 << 1,
1892         SPECIFIER_LONG      = 1 << 2,
1893         SPECIFIER_INT       = 1 << 3,
1894         SPECIFIER_DOUBLE    = 1 << 4,
1895         SPECIFIER_CHAR      = 1 << 5,
1896         SPECIFIER_SHORT     = 1 << 6,
1897         SPECIFIER_LONG_LONG = 1 << 7,
1898         SPECIFIER_FLOAT     = 1 << 8,
1899         SPECIFIER_BOOL      = 1 << 9,
1900         SPECIFIER_VOID      = 1 << 10,
1901 #ifdef PROVIDE_COMPLEX
1902         SPECIFIER_COMPLEX   = 1 << 11,
1903         SPECIFIER_IMAGINARY = 1 << 12,
1904 #endif
1905 } specifiers_t;
1906
1907 static type_t *create_builtin_type(symbol_t *const symbol,
1908                                    type_t *const real_type)
1909 {
1910         type_t *type            = allocate_type_zero(TYPE_BUILTIN, builtin_source_position);
1911         type->builtin.symbol    = symbol;
1912         type->builtin.real_type = real_type;
1913
1914         type_t *result = typehash_insert(type);
1915         if (type != result) {
1916                 free_type(type);
1917         }
1918
1919         return result;
1920 }
1921
1922 static type_t *get_typedef_type(symbol_t *symbol)
1923 {
1924         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1925         if(declaration == NULL
1926                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1927                 return NULL;
1928
1929         type_t *type               = allocate_type_zero(TYPE_TYPEDEF, declaration->source_position);
1930         type->typedeft.declaration = declaration;
1931
1932         return type;
1933 }
1934
1935 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1936 {
1937         type_t   *type            = NULL;
1938         unsigned  type_qualifiers = 0;
1939         unsigned  type_specifiers = 0;
1940         int       newtype         = 0;
1941
1942         specifiers->source_position = token.source_position;
1943
1944         while(true) {
1945                 switch(token.type) {
1946
1947                 /* storage class */
1948 #define MATCH_STORAGE_CLASS(token, class)                                  \
1949                 case token:                                                        \
1950                         if(specifiers->declared_storage_class != STORAGE_CLASS_NONE) { \
1951                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
1952                         }                                                              \
1953                         specifiers->declared_storage_class = class;                    \
1954                         next_token();                                                  \
1955                         break;
1956
1957                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1958                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1959                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1960                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1961                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1962
1963                 case T___thread:
1964                         switch (specifiers->declared_storage_class) {
1965                         case STORAGE_CLASS_NONE:
1966                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD;
1967                                 break;
1968
1969                         case STORAGE_CLASS_EXTERN:
1970                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD_EXTERN;
1971                                 break;
1972
1973                         case STORAGE_CLASS_STATIC:
1974                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD_STATIC;
1975                                 break;
1976
1977                         default:
1978                                 errorf(HERE, "multiple storage classes in declaration specifiers");
1979                                 break;
1980                         }
1981                         next_token();
1982                         break;
1983
1984                 /* type qualifiers */
1985 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1986                 case token:                                                     \
1987                         type_qualifiers |= qualifier;                               \
1988                         next_token();                                               \
1989                         break;
1990
1991                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1992                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1993                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1994
1995                 case T___extension__:
1996                         /* TODO */
1997                         next_token();
1998                         break;
1999
2000                 /* type specifiers */
2001 #define MATCH_SPECIFIER(token, specifier, name)                         \
2002                 case token:                                                     \
2003                         next_token();                                               \
2004                         if(type_specifiers & specifier) {                           \
2005                                 errorf(HERE, "multiple " name " type specifiers given"); \
2006                         } else {                                                    \
2007                                 type_specifiers |= specifier;                           \
2008                         }                                                           \
2009                         break;
2010
2011                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
2012                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
2013                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
2014                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
2015                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
2016                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
2017                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
2018                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
2019                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
2020 #ifdef PROVIDE_COMPLEX
2021                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
2022                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
2023 #endif
2024                 case T_forceinline:
2025                         /* only in microsoft mode */
2026                         specifiers->decl_modifiers |= DM_FORCEINLINE;
2027
2028                 case T_inline:
2029                         next_token();
2030                         specifiers->is_inline = true;
2031                         break;
2032
2033                 case T_long:
2034                         next_token();
2035                         if(type_specifiers & SPECIFIER_LONG_LONG) {
2036                                 errorf(HERE, "multiple type specifiers given");
2037                         } else if(type_specifiers & SPECIFIER_LONG) {
2038                                 type_specifiers |= SPECIFIER_LONG_LONG;
2039                         } else {
2040                                 type_specifiers |= SPECIFIER_LONG;
2041                         }
2042                         break;
2043
2044                 case T_struct: {
2045                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT, HERE);
2046
2047                         type->compound.declaration = parse_compound_type_specifier(true);
2048                         break;
2049                 }
2050                 case T_union: {
2051                         type = allocate_type_zero(TYPE_COMPOUND_UNION, HERE);
2052
2053                         type->compound.declaration = parse_compound_type_specifier(false);
2054                         break;
2055                 }
2056                 case T_enum:
2057                         type = parse_enum_specifier();
2058                         break;
2059                 case T___typeof__:
2060                         type = parse_typeof();
2061                         break;
2062                 case T___builtin_va_list:
2063                         type = duplicate_type(type_valist);
2064                         next_token();
2065                         break;
2066
2067                 case T___attribute__:
2068                         parse_attributes();
2069                         break;
2070
2071                 case T_IDENTIFIER: {
2072                         /* only parse identifier if we haven't found a type yet */
2073                         if(type != NULL || type_specifiers != 0)
2074                                 goto finish_specifiers;
2075
2076                         type_t *typedef_type = get_typedef_type(token.v.symbol);
2077
2078                         if(typedef_type == NULL)
2079                                 goto finish_specifiers;
2080
2081                         next_token();
2082                         type = typedef_type;
2083                         break;
2084                 }
2085
2086                 /* function specifier */
2087                 default:
2088                         goto finish_specifiers;
2089                 }
2090         }
2091
2092 finish_specifiers:
2093
2094         if(type == NULL) {
2095                 atomic_type_kind_t atomic_type;
2096
2097                 /* match valid basic types */
2098                 switch(type_specifiers) {
2099                 case SPECIFIER_VOID:
2100                         atomic_type = ATOMIC_TYPE_VOID;
2101                         break;
2102                 case SPECIFIER_CHAR:
2103                         atomic_type = ATOMIC_TYPE_CHAR;
2104                         break;
2105                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2106                         atomic_type = ATOMIC_TYPE_SCHAR;
2107                         break;
2108                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2109                         atomic_type = ATOMIC_TYPE_UCHAR;
2110                         break;
2111                 case SPECIFIER_SHORT:
2112                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2113                 case SPECIFIER_SHORT | SPECIFIER_INT:
2114                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2115                         atomic_type = ATOMIC_TYPE_SHORT;
2116                         break;
2117                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2118                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2119                         atomic_type = ATOMIC_TYPE_USHORT;
2120                         break;
2121                 case SPECIFIER_INT:
2122                 case SPECIFIER_SIGNED:
2123                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2124                         atomic_type = ATOMIC_TYPE_INT;
2125                         break;
2126                 case SPECIFIER_UNSIGNED:
2127                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2128                         atomic_type = ATOMIC_TYPE_UINT;
2129                         break;
2130                 case SPECIFIER_LONG:
2131                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2132                 case SPECIFIER_LONG | SPECIFIER_INT:
2133                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2134                         atomic_type = ATOMIC_TYPE_LONG;
2135                         break;
2136                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2137                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2138                         atomic_type = ATOMIC_TYPE_ULONG;
2139                         break;
2140                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2141                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2142                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2143                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2144                         | SPECIFIER_INT:
2145                         atomic_type = ATOMIC_TYPE_LONGLONG;
2146                         break;
2147                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2148                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2149                         | SPECIFIER_INT:
2150                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2151                         break;
2152                 case SPECIFIER_FLOAT:
2153                         atomic_type = ATOMIC_TYPE_FLOAT;
2154                         break;
2155                 case SPECIFIER_DOUBLE:
2156                         atomic_type = ATOMIC_TYPE_DOUBLE;
2157                         break;
2158                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2159                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2160                         break;
2161                 case SPECIFIER_BOOL:
2162                         atomic_type = ATOMIC_TYPE_BOOL;
2163                         break;
2164 #ifdef PROVIDE_COMPLEX
2165                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2166                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
2167                         break;
2168                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2169                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
2170                         break;
2171                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2172                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
2173                         break;
2174                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2175                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
2176                         break;
2177                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2178                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
2179                         break;
2180                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2181                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
2182                         break;
2183 #endif
2184                 default:
2185                         /* invalid specifier combination, give an error message */
2186                         if(type_specifiers == 0) {
2187                                 if (! strict_mode) {
2188                                         if (warning.implicit_int) {
2189                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
2190                                         }
2191                                         atomic_type = ATOMIC_TYPE_INT;
2192                                         break;
2193                                 } else {
2194                                         errorf(HERE, "no type specifiers given in declaration");
2195                                 }
2196                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
2197                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
2198                                 errorf(HERE, "signed and unsigned specifiers gives");
2199                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
2200                                 errorf(HERE, "only integer types can be signed or unsigned");
2201                         } else {
2202                                 errorf(HERE, "multiple datatypes in declaration");
2203                         }
2204                         atomic_type = ATOMIC_TYPE_INVALID;
2205                 }
2206
2207                 type               = allocate_type_zero(TYPE_ATOMIC, builtin_source_position);
2208                 type->atomic.akind = atomic_type;
2209                 newtype            = 1;
2210         } else {
2211                 if(type_specifiers != 0) {
2212                         errorf(HERE, "multiple datatypes in declaration");
2213                 }
2214         }
2215
2216         type->base.qualifiers = type_qualifiers;
2217
2218         type_t *result = typehash_insert(type);
2219         if(newtype && result != type) {
2220                 free_type(type);
2221         }
2222
2223         specifiers->type = result;
2224 }
2225
2226 static type_qualifiers_t parse_type_qualifiers(void)
2227 {
2228         type_qualifiers_t type_qualifiers = TYPE_QUALIFIER_NONE;
2229
2230         while(true) {
2231                 switch(token.type) {
2232                 /* type qualifiers */
2233                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2234                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2235                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2236
2237                 default:
2238                         return type_qualifiers;
2239                 }
2240         }
2241 }
2242
2243 static declaration_t *parse_identifier_list(void)
2244 {
2245         declaration_t *declarations     = NULL;
2246         declaration_t *last_declaration = NULL;
2247         do {
2248                 declaration_t *const declaration = allocate_declaration_zero();
2249                 declaration->type            = NULL; /* a K&R parameter list has no types, yet */
2250                 declaration->source_position = token.source_position;
2251                 declaration->symbol          = token.v.symbol;
2252                 next_token();
2253
2254                 if(last_declaration != NULL) {
2255                         last_declaration->next = declaration;
2256                 } else {
2257                         declarations = declaration;
2258                 }
2259                 last_declaration = declaration;
2260
2261                 if(token.type != ',')
2262                         break;
2263                 next_token();
2264         } while(token.type == T_IDENTIFIER);
2265
2266         return declarations;
2267 }
2268
2269 static void semantic_parameter(declaration_t *declaration)
2270 {
2271         /* TODO: improve error messages */
2272
2273         if(declaration->declared_storage_class == STORAGE_CLASS_TYPEDEF) {
2274                 errorf(HERE, "typedef not allowed in parameter list");
2275         } else if(declaration->declared_storage_class != STORAGE_CLASS_NONE
2276                         && declaration->declared_storage_class != STORAGE_CLASS_REGISTER) {
2277                 errorf(HERE, "parameter may only have none or register storage class");
2278         }
2279
2280         type_t *const orig_type = declaration->type;
2281         type_t *      type      = skip_typeref(orig_type);
2282
2283         /* Array as last part of a parameter type is just syntactic sugar.  Turn it
2284          * into a pointer. § 6.7.5.3 (7) */
2285         if (is_type_array(type)) {
2286                 type_t *const element_type = type->array.element_type;
2287
2288                 type = make_pointer_type(element_type, type->base.qualifiers);
2289
2290                 declaration->type = type;
2291         }
2292
2293         if(is_type_incomplete(type)) {
2294                 errorf(HERE, "incomplete type '%T' not allowed for parameter '%Y'",
2295                        orig_type, declaration->symbol);
2296         }
2297 }
2298
2299 static declaration_t *parse_parameter(void)
2300 {
2301         declaration_specifiers_t specifiers;
2302         memset(&specifiers, 0, sizeof(specifiers));
2303
2304         parse_declaration_specifiers(&specifiers);
2305
2306         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
2307
2308         semantic_parameter(declaration);
2309
2310         return declaration;
2311 }
2312
2313 static declaration_t *parse_parameters(function_type_t *type)
2314 {
2315         if(token.type == T_IDENTIFIER) {
2316                 symbol_t *symbol = token.v.symbol;
2317                 if(!is_typedef_symbol(symbol)) {
2318                         type->kr_style_parameters = true;
2319                         return parse_identifier_list();
2320                 }
2321         }
2322
2323         if(token.type == ')') {
2324                 type->unspecified_parameters = 1;
2325                 return NULL;
2326         }
2327         if(token.type == T_void && look_ahead(1)->type == ')') {
2328                 next_token();
2329                 return NULL;
2330         }
2331
2332         declaration_t        *declarations = NULL;
2333         declaration_t        *declaration;
2334         declaration_t        *last_declaration = NULL;
2335         function_parameter_t *parameter;
2336         function_parameter_t *last_parameter = NULL;
2337
2338         while(true) {
2339                 switch(token.type) {
2340                 case T_DOTDOTDOT:
2341                         next_token();
2342                         type->variadic = 1;
2343                         return declarations;
2344
2345                 case T_IDENTIFIER:
2346                 case T___extension__:
2347                 DECLARATION_START
2348                         declaration = parse_parameter();
2349
2350                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
2351                         memset(parameter, 0, sizeof(parameter[0]));
2352                         parameter->type = declaration->type;
2353
2354                         if(last_parameter != NULL) {
2355                                 last_declaration->next = declaration;
2356                                 last_parameter->next   = parameter;
2357                         } else {
2358                                 type->parameters = parameter;
2359                                 declarations     = declaration;
2360                         }
2361                         last_parameter   = parameter;
2362                         last_declaration = declaration;
2363                         break;
2364
2365                 default:
2366                         return declarations;
2367                 }
2368                 if(token.type != ',')
2369                         return declarations;
2370                 next_token();
2371         }
2372 }
2373
2374 typedef enum {
2375         CONSTRUCT_INVALID,
2376         CONSTRUCT_POINTER,
2377         CONSTRUCT_FUNCTION,
2378         CONSTRUCT_ARRAY
2379 } construct_type_kind_t;
2380
2381 typedef struct construct_type_t construct_type_t;
2382 struct construct_type_t {
2383         construct_type_kind_t  kind;
2384         construct_type_t      *next;
2385 };
2386
2387 typedef struct parsed_pointer_t parsed_pointer_t;
2388 struct parsed_pointer_t {
2389         construct_type_t  construct_type;
2390         type_qualifiers_t type_qualifiers;
2391 };
2392
2393 typedef struct construct_function_type_t construct_function_type_t;
2394 struct construct_function_type_t {
2395         construct_type_t  construct_type;
2396         type_t           *function_type;
2397 };
2398
2399 typedef struct parsed_array_t parsed_array_t;
2400 struct parsed_array_t {
2401         construct_type_t  construct_type;
2402         type_qualifiers_t type_qualifiers;
2403         bool              is_static;
2404         bool              is_variable;
2405         expression_t     *size;
2406 };
2407
2408 typedef struct construct_base_type_t construct_base_type_t;
2409 struct construct_base_type_t {
2410         construct_type_t  construct_type;
2411         type_t           *type;
2412 };
2413
2414 static construct_type_t *parse_pointer_declarator(void)
2415 {
2416         eat('*');
2417
2418         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
2419         memset(pointer, 0, sizeof(pointer[0]));
2420         pointer->construct_type.kind = CONSTRUCT_POINTER;
2421         pointer->type_qualifiers     = parse_type_qualifiers();
2422
2423         return (construct_type_t*) pointer;
2424 }
2425
2426 static construct_type_t *parse_array_declarator(void)
2427 {
2428         eat('[');
2429
2430         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
2431         memset(array, 0, sizeof(array[0]));
2432         array->construct_type.kind = CONSTRUCT_ARRAY;
2433
2434         if(token.type == T_static) {
2435                 array->is_static = true;
2436                 next_token();
2437         }
2438
2439         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
2440         if(type_qualifiers != 0) {
2441                 if(token.type == T_static) {
2442                         array->is_static = true;
2443                         next_token();
2444                 }
2445         }
2446         array->type_qualifiers = type_qualifiers;
2447
2448         if(token.type == '*' && look_ahead(1)->type == ']') {
2449                 array->is_variable = true;
2450                 next_token();
2451         } else if(token.type != ']') {
2452                 array->size = parse_assignment_expression();
2453         }
2454
2455         expect(']');
2456
2457         return (construct_type_t*) array;
2458 end_error:
2459         return NULL;
2460 }
2461
2462 static construct_type_t *parse_function_declarator(declaration_t *declaration)
2463 {
2464         eat('(');
2465
2466         type_t *type;
2467         if(declaration != NULL) {
2468                 type = allocate_type_zero(TYPE_FUNCTION, declaration->source_position);
2469         } else {
2470                 type = allocate_type_zero(TYPE_FUNCTION, token.source_position);
2471         }
2472
2473         declaration_t *parameters = parse_parameters(&type->function);
2474         if(declaration != NULL) {
2475                 declaration->scope.declarations = parameters;
2476         }
2477
2478         construct_function_type_t *construct_function_type =
2479                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
2480         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
2481         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
2482         construct_function_type->function_type       = type;
2483
2484         expect(')');
2485
2486         return (construct_type_t*) construct_function_type;
2487 end_error:
2488         return NULL;
2489 }
2490
2491 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
2492                 bool may_be_abstract)
2493 {
2494         /* construct a single linked list of construct_type_t's which describe
2495          * how to construct the final declarator type */
2496         construct_type_t *first = NULL;
2497         construct_type_t *last  = NULL;
2498
2499         /* pointers */
2500         while(token.type == '*') {
2501                 construct_type_t *type = parse_pointer_declarator();
2502
2503                 if(last == NULL) {
2504                         first = type;
2505                         last  = type;
2506                 } else {
2507                         last->next = type;
2508                         last       = type;
2509                 }
2510         }
2511
2512         /* TODO: find out if this is correct */
2513         parse_attributes();
2514
2515         construct_type_t *inner_types = NULL;
2516
2517         switch(token.type) {
2518         case T_IDENTIFIER:
2519                 if(declaration == NULL) {
2520                         errorf(HERE, "no identifier expected in typename");
2521                 } else {
2522                         declaration->symbol          = token.v.symbol;
2523                         declaration->source_position = token.source_position;
2524                 }
2525                 next_token();
2526                 break;
2527         case '(':
2528                 next_token();
2529                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
2530                 expect(')');
2531                 break;
2532         default:
2533                 if(may_be_abstract)
2534                         break;
2535                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
2536                 /* avoid a loop in the outermost scope, because eat_statement doesn't
2537                  * eat '}' */
2538                 if(token.type == '}' && current_function == NULL) {
2539                         next_token();
2540                 } else {
2541                         eat_statement();
2542                 }
2543                 return NULL;
2544         }
2545
2546         construct_type_t *p = last;
2547
2548         while(true) {
2549                 construct_type_t *type;
2550                 switch(token.type) {
2551                 case '(':
2552                         type = parse_function_declarator(declaration);
2553                         break;
2554                 case '[':
2555                         type = parse_array_declarator();
2556                         break;
2557                 default:
2558                         goto declarator_finished;
2559                 }
2560
2561                 /* insert in the middle of the list (behind p) */
2562                 if(p != NULL) {
2563                         type->next = p->next;
2564                         p->next    = type;
2565                 } else {
2566                         type->next = first;
2567                         first      = type;
2568                 }
2569                 if(last == p) {
2570                         last = type;
2571                 }
2572         }
2573
2574 declarator_finished:
2575         parse_attributes();
2576
2577         /* append inner_types at the end of the list, we don't to set last anymore
2578          * as it's not needed anymore */
2579         if(last == NULL) {
2580                 assert(first == NULL);
2581                 first = inner_types;
2582         } else {
2583                 last->next = inner_types;
2584         }
2585
2586         return first;
2587 end_error:
2588         return NULL;
2589 }
2590
2591 static type_t *construct_declarator_type(construct_type_t *construct_list,
2592                                          type_t *type)
2593 {
2594         construct_type_t *iter = construct_list;
2595         for( ; iter != NULL; iter = iter->next) {
2596                 switch(iter->kind) {
2597                 case CONSTRUCT_INVALID:
2598                         panic("invalid type construction found");
2599                 case CONSTRUCT_FUNCTION: {
2600                         construct_function_type_t *construct_function_type
2601                                 = (construct_function_type_t*) iter;
2602
2603                         type_t *function_type = construct_function_type->function_type;
2604
2605                         function_type->function.return_type = type;
2606
2607                         type_t *skipped_return_type = skip_typeref(type);
2608                         if (is_type_function(skipped_return_type)) {
2609                                 errorf(HERE, "function returning function is not allowed");
2610                                 type = type_error_type;
2611                         } else if (is_type_array(skipped_return_type)) {
2612                                 errorf(HERE, "function returning array is not allowed");
2613                                 type = type_error_type;
2614                         } else {
2615                                 type = function_type;
2616                         }
2617                         break;
2618                 }
2619
2620                 case CONSTRUCT_POINTER: {
2621                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
2622                         type_t           *pointer_type   = allocate_type_zero(TYPE_POINTER, (source_position_t){NULL, 0});
2623                         pointer_type->pointer.points_to  = type;
2624                         pointer_type->base.qualifiers    = parsed_pointer->type_qualifiers;
2625
2626                         type = pointer_type;
2627                         break;
2628                 }
2629
2630                 case CONSTRUCT_ARRAY: {
2631                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
2632                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY, (source_position_t){NULL, 0});
2633
2634                         expression_t *size_expression = parsed_array->size;
2635                         if(size_expression != NULL) {
2636                                 size_expression
2637                                         = create_implicit_cast(size_expression, type_size_t);
2638                         }
2639
2640                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
2641                         array_type->array.element_type    = type;
2642                         array_type->array.is_static       = parsed_array->is_static;
2643                         array_type->array.is_variable     = parsed_array->is_variable;
2644                         array_type->array.size_expression = size_expression;
2645
2646                         if(size_expression != NULL) {
2647                                 if(is_constant_expression(size_expression)) {
2648                                         array_type->array.size_constant = true;
2649                                         array_type->array.size
2650                                                 = fold_constant(size_expression);
2651                                 } else {
2652                                         array_type->array.is_vla = true;
2653                                 }
2654                         }
2655
2656                         type_t *skipped_type = skip_typeref(type);
2657                         if (is_type_atomic(skipped_type, ATOMIC_TYPE_VOID)) {
2658                                 errorf(HERE, "array of void is not allowed");
2659                                 type = type_error_type;
2660                         } else {
2661                                 type = array_type;
2662                         }
2663                         break;
2664                 }
2665                 }
2666
2667                 type_t *hashed_type = typehash_insert(type);
2668                 if(hashed_type != type) {
2669                         /* the function type was constructed earlier freeing it here will
2670                          * destroy other types... */
2671                         if(iter->kind != CONSTRUCT_FUNCTION) {
2672                                 free_type(type);
2673                         }
2674                         type = hashed_type;
2675                 }
2676         }
2677
2678         return type;
2679 }
2680
2681 static declaration_t *parse_declarator(
2682                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
2683 {
2684         declaration_t *const declaration    = allocate_declaration_zero();
2685         declaration->declared_storage_class = specifiers->declared_storage_class;
2686         declaration->modifiers              = specifiers->decl_modifiers;
2687         declaration->is_inline              = specifiers->is_inline;
2688
2689         declaration->storage_class          = specifiers->declared_storage_class;
2690         if(declaration->storage_class == STORAGE_CLASS_NONE
2691                         && scope != global_scope) {
2692                 declaration->storage_class = STORAGE_CLASS_AUTO;
2693         }
2694
2695         construct_type_t *construct_type
2696                 = parse_inner_declarator(declaration, may_be_abstract);
2697         type_t *const type = specifiers->type;
2698         declaration->type = construct_declarator_type(construct_type, type);
2699
2700         if(construct_type != NULL) {
2701                 obstack_free(&temp_obst, construct_type);
2702         }
2703
2704         return declaration;
2705 }
2706
2707 static type_t *parse_abstract_declarator(type_t *base_type)
2708 {
2709         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2710
2711         type_t *result = construct_declarator_type(construct_type, base_type);
2712         if(construct_type != NULL) {
2713                 obstack_free(&temp_obst, construct_type);
2714         }
2715
2716         return result;
2717 }
2718
2719 static declaration_t *append_declaration(declaration_t* const declaration)
2720 {
2721         if (last_declaration != NULL) {
2722                 last_declaration->next = declaration;
2723         } else {
2724                 scope->declarations = declaration;
2725         }
2726         last_declaration = declaration;
2727         return declaration;
2728 }
2729
2730 /**
2731  * Check if the declaration of main is suspicious.  main should be a
2732  * function with external linkage, returning int, taking either zero
2733  * arguments, two, or three arguments of appropriate types, ie.
2734  *
2735  * int main([ int argc, char **argv [, char **env ] ]).
2736  *
2737  * @param decl    the declaration to check
2738  * @param type    the function type of the declaration
2739  */
2740 static void check_type_of_main(const declaration_t *const decl, const function_type_t *const func_type)
2741 {
2742         if (decl->storage_class == STORAGE_CLASS_STATIC) {
2743                 warningf(decl->source_position, "'main' is normally a non-static function");
2744         }
2745         if (skip_typeref(func_type->return_type) != type_int) {
2746                 warningf(decl->source_position, "return type of 'main' should be 'int', but is '%T'", func_type->return_type);
2747         }
2748         const function_parameter_t *parm = func_type->parameters;
2749         if (parm != NULL) {
2750                 type_t *const first_type = parm->type;
2751                 if (!types_compatible(skip_typeref(first_type), type_int)) {
2752                         warningf(decl->source_position, "first argument of 'main' should be 'int', but is '%T'", first_type);
2753                 }
2754                 parm = parm->next;
2755                 if (parm != NULL) {
2756                         type_t *const second_type = parm->type;
2757                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
2758                                 warningf(decl->source_position, "second argument of 'main' should be 'char**', but is '%T'", second_type);
2759                         }
2760                         parm = parm->next;
2761                         if (parm != NULL) {
2762                                 type_t *const third_type = parm->type;
2763                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
2764                                         warningf(decl->source_position, "third argument of 'main' should be 'char**', but is '%T'", third_type);
2765                                 }
2766                                 parm = parm->next;
2767                                 if (parm != NULL) {
2768                                         warningf(decl->source_position, "'main' takes only zero, two or three arguments");
2769                                 }
2770                         }
2771                 } else {
2772                         warningf(decl->source_position, "'main' takes only zero, two or three arguments");
2773                 }
2774         }
2775 }
2776
2777 /**
2778  * Check if a symbol is the equal to "main".
2779  */
2780 static bool is_sym_main(const symbol_t *const sym)
2781 {
2782         return strcmp(sym->string, "main") == 0;
2783 }
2784
2785 static declaration_t *internal_record_declaration(
2786         declaration_t *const declaration,
2787         const bool is_function_definition)
2788 {
2789         const symbol_t *const symbol  = declaration->symbol;
2790         const namespace_t     namespc = (namespace_t)declaration->namespc;
2791
2792         type_t *const orig_type = declaration->type;
2793         type_t *const type      = skip_typeref(orig_type);
2794         if (is_type_function(type) &&
2795                         type->function.unspecified_parameters &&
2796                         warning.strict_prototypes) {
2797                 warningf(declaration->source_position,
2798                          "function declaration '%#T' is not a prototype",
2799                          orig_type, declaration->symbol);
2800         }
2801
2802         if (is_function_definition && warning.main && is_sym_main(symbol)) {
2803                 check_type_of_main(declaration, &type->function);
2804         }
2805
2806         assert(declaration->symbol != NULL);
2807         declaration_t *previous_declaration = get_declaration(symbol, namespc);
2808
2809         assert(declaration != previous_declaration);
2810         if (previous_declaration != NULL) {
2811                 if (previous_declaration->parent_scope == scope) {
2812                         /* can happen for K&R style declarations */
2813                         if(previous_declaration->type == NULL) {
2814                                 previous_declaration->type = declaration->type;
2815                         }
2816
2817                         const type_t *prev_type = skip_typeref(previous_declaration->type);
2818                         if (!types_compatible(type, prev_type)) {
2819                                 errorf(declaration->source_position,
2820                                        "declaration '%#T' is incompatible with "
2821                                        "previous declaration '%#T'",
2822                                        orig_type, symbol, previous_declaration->type, symbol);
2823                                 errorf(previous_declaration->source_position,
2824                                        "previous declaration of '%Y' was here", symbol);
2825                         } else {
2826                                 unsigned old_storage_class
2827                                         = previous_declaration->storage_class;
2828                                 unsigned new_storage_class = declaration->storage_class;
2829
2830                                 if(is_type_incomplete(prev_type)) {
2831                                         previous_declaration->type = type;
2832                                         prev_type                  = type;
2833                                 }
2834
2835                                 /* pretend no storage class means extern for function
2836                                  * declarations (except if the previous declaration is neither
2837                                  * none nor extern) */
2838                                 if (is_type_function(type)) {
2839                                         switch (old_storage_class) {
2840                                                 case STORAGE_CLASS_NONE:
2841                                                         old_storage_class = STORAGE_CLASS_EXTERN;
2842
2843                                                 case STORAGE_CLASS_EXTERN:
2844                                                         if (is_function_definition) {
2845                                                                 if (warning.missing_prototypes &&
2846                                                                     prev_type->function.unspecified_parameters &&
2847                                                                     !is_sym_main(symbol)) {
2848                                                                         warningf(declaration->source_position,
2849                                                                                  "no previous prototype for '%#T'",
2850                                                                                  orig_type, symbol);
2851                                                                 }
2852                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
2853                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
2854                                                         }
2855                                                         break;
2856
2857                                                 default: break;
2858                                         }
2859                                 }
2860
2861                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
2862                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
2863 warn_redundant_declaration:
2864                                         if (warning.redundant_decls) {
2865                                                 warningf(declaration->source_position,
2866                                                          "redundant declaration for '%Y'", symbol);
2867                                                 warningf(previous_declaration->source_position,
2868                                                          "previous declaration of '%Y' was here",
2869                                                          symbol);
2870                                         }
2871                                 } else if (current_function == NULL) {
2872                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
2873                                                         new_storage_class == STORAGE_CLASS_STATIC) {
2874                                                 errorf(declaration->source_position,
2875                                                        "static declaration of '%Y' follows non-static declaration",
2876                                                        symbol);
2877                                                 errorf(previous_declaration->source_position,
2878                                                        "previous declaration of '%Y' was here", symbol);
2879                                         } else {
2880                                                 if (old_storage_class != STORAGE_CLASS_EXTERN && !is_function_definition) {
2881                                                         goto warn_redundant_declaration;
2882                                                 }
2883                                                 if (new_storage_class == STORAGE_CLASS_NONE) {
2884                                                         previous_declaration->storage_class = STORAGE_CLASS_NONE;
2885                                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
2886                                                 }
2887                                         }
2888                                 } else {
2889                                         if (old_storage_class == new_storage_class) {
2890                                                 errorf(declaration->source_position,
2891                                                        "redeclaration of '%Y'", symbol);
2892                                         } else {
2893                                                 errorf(declaration->source_position,
2894                                                        "redeclaration of '%Y' with different linkage",
2895                                                        symbol);
2896                                         }
2897                                         errorf(previous_declaration->source_position,
2898                                                "previous declaration of '%Y' was here", symbol);
2899                                 }
2900                         }
2901                         return previous_declaration;
2902                 }
2903         } else if (is_function_definition) {
2904                 if (declaration->storage_class != STORAGE_CLASS_STATIC) {
2905                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
2906                                 warningf(declaration->source_position,
2907                                          "no previous prototype for '%#T'", orig_type, symbol);
2908                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
2909                                 warningf(declaration->source_position,
2910                                          "no previous declaration for '%#T'", orig_type,
2911                                          symbol);
2912                         }
2913                 }
2914         } else if (warning.missing_declarations &&
2915             scope == global_scope &&
2916             !is_type_function(type) && (
2917               declaration->storage_class == STORAGE_CLASS_NONE ||
2918               declaration->storage_class == STORAGE_CLASS_THREAD
2919             )) {
2920                 warningf(declaration->source_position,
2921                          "no previous declaration for '%#T'", orig_type, symbol);
2922         }
2923
2924         assert(declaration->parent_scope == NULL);
2925         assert(scope != NULL);
2926
2927         declaration->parent_scope = scope;
2928
2929         environment_push(declaration);
2930         return append_declaration(declaration);
2931 }
2932
2933 static declaration_t *record_declaration(declaration_t *declaration)
2934 {
2935         return internal_record_declaration(declaration, false);
2936 }
2937
2938 static declaration_t *record_function_definition(declaration_t *declaration)
2939 {
2940         return internal_record_declaration(declaration, true);
2941 }
2942
2943 static void parser_error_multiple_definition(declaration_t *declaration,
2944                 const source_position_t source_position)
2945 {
2946         errorf(source_position, "multiple definition of symbol '%Y'",
2947                declaration->symbol);
2948         errorf(declaration->source_position,
2949                "this is the location of the previous definition.");
2950 }
2951
2952 static bool is_declaration_specifier(const token_t *token,
2953                                      bool only_type_specifiers)
2954 {
2955         switch(token->type) {
2956                 TYPE_SPECIFIERS
2957                         return true;
2958                 case T_IDENTIFIER:
2959                         return is_typedef_symbol(token->v.symbol);
2960
2961                 case T___extension__:
2962                 STORAGE_CLASSES
2963                 TYPE_QUALIFIERS
2964                         return !only_type_specifiers;
2965
2966                 default:
2967                         return false;
2968         }
2969 }
2970
2971 static void parse_init_declarator_rest(declaration_t *declaration)
2972 {
2973         eat('=');
2974
2975         type_t *orig_type = declaration->type;
2976         type_t *type      = skip_typeref(orig_type);
2977
2978         if(declaration->init.initializer != NULL) {
2979                 parser_error_multiple_definition(declaration, token.source_position);
2980         }
2981
2982         bool must_be_constant = false;
2983         if(declaration->storage_class == STORAGE_CLASS_STATIC
2984                         || declaration->storage_class == STORAGE_CLASS_THREAD_STATIC
2985                         || declaration->parent_scope == global_scope) {
2986                 must_be_constant = true;
2987         }
2988
2989         parse_initializer_env_t env;
2990         env.type             = orig_type;
2991         env.must_be_constant = must_be_constant;
2992         env.declaration      = declaration;
2993
2994         initializer_t *initializer = parse_initializer(&env);
2995
2996         if(env.type != orig_type) {
2997                 orig_type         = env.type;
2998                 type              = skip_typeref(orig_type);
2999                 declaration->type = env.type;
3000         }
3001
3002         if(is_type_function(type)) {
3003                 errorf(declaration->source_position,
3004                        "initializers not allowed for function types at declator '%Y' (type '%T')",
3005                        declaration->symbol, orig_type);
3006         } else {
3007                 declaration->init.initializer = initializer;
3008         }
3009 }
3010
3011 /* parse rest of a declaration without any declarator */
3012 static void parse_anonymous_declaration_rest(
3013                 const declaration_specifiers_t *specifiers,
3014                 parsed_declaration_func finished_declaration)
3015 {
3016         eat(';');
3017
3018         declaration_t *const declaration    = allocate_declaration_zero();
3019         declaration->type                   = specifiers->type;
3020         declaration->declared_storage_class = specifiers->declared_storage_class;
3021         declaration->source_position        = specifiers->source_position;
3022
3023         if (declaration->declared_storage_class != STORAGE_CLASS_NONE) {
3024                 warningf(declaration->source_position, "useless storage class in empty declaration");
3025         }
3026         declaration->storage_class = STORAGE_CLASS_NONE;
3027
3028         type_t *type = declaration->type;
3029         switch (type->kind) {
3030                 case TYPE_COMPOUND_STRUCT:
3031                 case TYPE_COMPOUND_UNION: {
3032                         if (type->compound.declaration->symbol == NULL) {
3033                                 warningf(declaration->source_position, "unnamed struct/union that defines no instances");
3034                         }
3035                         break;
3036                 }
3037
3038                 case TYPE_ENUM:
3039                         break;
3040
3041                 default:
3042                         warningf(declaration->source_position, "empty declaration");
3043                         break;
3044         }
3045
3046         finished_declaration(declaration);
3047 }
3048
3049 static void parse_declaration_rest(declaration_t *ndeclaration,
3050                 const declaration_specifiers_t *specifiers,
3051                 parsed_declaration_func finished_declaration)
3052 {
3053         while(true) {
3054                 declaration_t *declaration = finished_declaration(ndeclaration);
3055
3056                 type_t *orig_type = declaration->type;
3057                 type_t *type      = skip_typeref(orig_type);
3058
3059                 if (type->kind != TYPE_FUNCTION &&
3060                     declaration->is_inline &&
3061                     is_type_valid(type)) {
3062                         warningf(declaration->source_position,
3063                                  "variable '%Y' declared 'inline'\n", declaration->symbol);
3064                 }
3065
3066                 if(token.type == '=') {
3067                         parse_init_declarator_rest(declaration);
3068                 }
3069
3070                 if(token.type != ',')
3071                         break;
3072                 eat(',');
3073
3074                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
3075         }
3076         expect(';');
3077
3078 end_error:
3079         ;
3080 }
3081
3082 static declaration_t *finished_kr_declaration(declaration_t *declaration)
3083 {
3084         symbol_t *symbol  = declaration->symbol;
3085         if(symbol == NULL) {
3086                 errorf(HERE, "anonymous declaration not valid as function parameter");
3087                 return declaration;
3088         }
3089         namespace_t namespc = (namespace_t) declaration->namespc;
3090         if(namespc != NAMESPACE_NORMAL) {
3091                 return record_declaration(declaration);
3092         }
3093
3094         declaration_t *previous_declaration = get_declaration(symbol, namespc);
3095         if(previous_declaration == NULL ||
3096                         previous_declaration->parent_scope != scope) {
3097                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
3098                        symbol);
3099                 return declaration;
3100         }
3101
3102         if(previous_declaration->type == NULL) {
3103                 previous_declaration->type          = declaration->type;
3104                 previous_declaration->declared_storage_class = declaration->declared_storage_class;
3105                 previous_declaration->storage_class = declaration->storage_class;
3106                 previous_declaration->parent_scope  = scope;
3107                 return previous_declaration;
3108         } else {
3109                 return record_declaration(declaration);
3110         }
3111 }
3112
3113 static void parse_declaration(parsed_declaration_func finished_declaration)
3114 {
3115         declaration_specifiers_t specifiers;
3116         memset(&specifiers, 0, sizeof(specifiers));
3117         parse_declaration_specifiers(&specifiers);
3118
3119         if(token.type == ';') {
3120                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
3121         } else {
3122                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
3123                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
3124         }
3125 }
3126
3127 static void parse_kr_declaration_list(declaration_t *declaration)
3128 {
3129         type_t *type = skip_typeref(declaration->type);
3130         if(!is_type_function(type))
3131                 return;
3132
3133         if(!type->function.kr_style_parameters)
3134                 return;
3135
3136         /* push function parameters */
3137         int       top        = environment_top();
3138         scope_t  *last_scope = scope;
3139         set_scope(&declaration->scope);
3140
3141         declaration_t *parameter = declaration->scope.declarations;
3142         for( ; parameter != NULL; parameter = parameter->next) {
3143                 assert(parameter->parent_scope == NULL);
3144                 parameter->parent_scope = scope;
3145                 environment_push(parameter);
3146         }
3147
3148         /* parse declaration list */
3149         while(is_declaration_specifier(&token, false)) {
3150                 parse_declaration(finished_kr_declaration);
3151         }
3152
3153         /* pop function parameters */
3154         assert(scope == &declaration->scope);
3155         set_scope(last_scope);
3156         environment_pop_to(top);
3157
3158         /* update function type */
3159         type_t *new_type = duplicate_type(type);
3160         new_type->function.kr_style_parameters = false;
3161
3162         function_parameter_t *parameters     = NULL;
3163         function_parameter_t *last_parameter = NULL;
3164
3165         declaration_t *parameter_declaration = declaration->scope.declarations;
3166         for( ; parameter_declaration != NULL;
3167                         parameter_declaration = parameter_declaration->next) {
3168                 type_t *parameter_type = parameter_declaration->type;
3169                 if(parameter_type == NULL) {
3170                         if (strict_mode) {
3171                                 errorf(HERE, "no type specified for function parameter '%Y'",
3172                                        parameter_declaration->symbol);
3173                         } else {
3174                                 if (warning.implicit_int) {
3175                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
3176                                                 parameter_declaration->symbol);
3177                                 }
3178                                 parameter_type              = type_int;
3179                                 parameter_declaration->type = parameter_type;
3180                         }
3181                 }
3182
3183                 semantic_parameter(parameter_declaration);
3184                 parameter_type = parameter_declaration->type;
3185
3186                 function_parameter_t *function_parameter
3187                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
3188                 memset(function_parameter, 0, sizeof(function_parameter[0]));
3189
3190                 function_parameter->type = parameter_type;
3191                 if(last_parameter != NULL) {
3192                         last_parameter->next = function_parameter;
3193                 } else {
3194                         parameters = function_parameter;
3195                 }
3196                 last_parameter = function_parameter;
3197         }
3198         new_type->function.parameters = parameters;
3199
3200         type = typehash_insert(new_type);
3201         if(type != new_type) {
3202                 obstack_free(type_obst, new_type);
3203         }
3204
3205         declaration->type = type;
3206 }
3207
3208 static bool first_err = true;
3209
3210 /**
3211  * When called with first_err set, prints the name of the current function,
3212  * else does noting.
3213  */
3214 static void print_in_function(void) {
3215         if (first_err) {
3216                 first_err = false;
3217                 diagnosticf("%s: In function '%Y':\n",
3218                         current_function->source_position.input_name,
3219                         current_function->symbol);
3220         }
3221 }
3222
3223 /**
3224  * Check if all labels are defined in the current function.
3225  * Check if all labels are used in the current function.
3226  */
3227 static void check_labels(void)
3228 {
3229         for (const goto_statement_t *goto_statement = goto_first;
3230             goto_statement != NULL;
3231             goto_statement = goto_statement->next) {
3232                 declaration_t *label = goto_statement->label;
3233
3234                 label->used = true;
3235                 if (label->source_position.input_name == NULL) {
3236                         print_in_function();
3237                         errorf(goto_statement->base.source_position,
3238                                "label '%Y' used but not defined", label->symbol);
3239                  }
3240         }
3241         goto_first = goto_last = NULL;
3242
3243         if (warning.unused_label) {
3244                 for (const label_statement_t *label_statement = label_first;
3245                          label_statement != NULL;
3246                          label_statement = label_statement->next) {
3247                         const declaration_t *label = label_statement->label;
3248
3249                         if (! label->used) {
3250                                 print_in_function();
3251                                 warningf(label_statement->base.source_position,
3252                                         "label '%Y' defined but not used", label->symbol);
3253                         }
3254                 }
3255         }
3256         label_first = label_last = NULL;
3257 }
3258
3259 /**
3260  * Check declarations of current_function for unused entities.
3261  */
3262 static void check_declarations(void)
3263 {
3264         if (warning.unused_parameter) {
3265                 const scope_t *scope = &current_function->scope;
3266
3267                 const declaration_t *parameter = scope->declarations;
3268                 for (; parameter != NULL; parameter = parameter->next) {
3269                         if (! parameter->used) {
3270                                 print_in_function();
3271                                 warningf(parameter->source_position,
3272                                         "unused parameter '%Y'", parameter->symbol);
3273                         }
3274                 }
3275         }
3276         if (warning.unused_variable) {
3277         }
3278 }
3279
3280 static void parse_external_declaration(void)
3281 {
3282         /* function-definitions and declarations both start with declaration
3283          * specifiers */
3284         declaration_specifiers_t specifiers;
3285         memset(&specifiers, 0, sizeof(specifiers));
3286         parse_declaration_specifiers(&specifiers);
3287
3288         /* must be a declaration */
3289         if(token.type == ';') {
3290                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
3291                 return;
3292         }
3293
3294         /* declarator is common to both function-definitions and declarations */
3295         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
3296
3297         /* must be a declaration */
3298         if(token.type == ',' || token.type == '=' || token.type == ';') {
3299                 parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
3300                 return;
3301         }
3302
3303         /* must be a function definition */
3304         parse_kr_declaration_list(ndeclaration);
3305
3306         if(token.type != '{') {
3307                 parse_error_expected("while parsing function definition", '{', 0);
3308                 eat_statement();
3309                 return;
3310         }
3311
3312         type_t *type = ndeclaration->type;
3313
3314         /* note that we don't skip typerefs: the standard doesn't allow them here
3315          * (so we can't use is_type_function here) */
3316         if(type->kind != TYPE_FUNCTION) {
3317                 if (is_type_valid(type)) {
3318                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
3319                                type, ndeclaration->symbol);
3320                 }
3321                 eat_block();
3322                 return;
3323         }
3324
3325         /* § 6.7.5.3 (14) a function definition with () means no
3326          * parameters (and not unspecified parameters) */
3327         if(type->function.unspecified_parameters) {
3328                 type_t *duplicate = duplicate_type(type);
3329                 duplicate->function.unspecified_parameters = false;
3330
3331                 type = typehash_insert(duplicate);
3332                 if(type != duplicate) {
3333                         obstack_free(type_obst, duplicate);
3334                 }
3335                 ndeclaration->type = type;
3336         }
3337
3338         declaration_t *const declaration = record_function_definition(ndeclaration);
3339         if(ndeclaration != declaration) {
3340                 declaration->scope = ndeclaration->scope;
3341         }
3342         type = skip_typeref(declaration->type);
3343
3344         /* push function parameters and switch scope */
3345         int       top        = environment_top();
3346         scope_t  *last_scope = scope;
3347         set_scope(&declaration->scope);
3348
3349         declaration_t *parameter = declaration->scope.declarations;
3350         for( ; parameter != NULL; parameter = parameter->next) {
3351                 if(parameter->parent_scope == &ndeclaration->scope) {
3352                         parameter->parent_scope = scope;
3353                 }
3354                 assert(parameter->parent_scope == NULL
3355                                 || parameter->parent_scope == scope);
3356                 parameter->parent_scope = scope;
3357                 environment_push(parameter);
3358         }
3359
3360         if(declaration->init.statement != NULL) {
3361                 parser_error_multiple_definition(declaration, token.source_position);
3362                 eat_block();
3363                 goto end_of_parse_external_declaration;
3364         } else {
3365                 /* parse function body */
3366                 int            label_stack_top      = label_top();
3367                 declaration_t *old_current_function = current_function;
3368                 current_function                    = declaration;
3369
3370                 declaration->init.statement = parse_compound_statement();
3371                 first_err = true;
3372                 check_labels();
3373                 check_declarations();
3374
3375                 assert(current_function == declaration);
3376                 current_function = old_current_function;
3377                 label_pop_to(label_stack_top);
3378         }
3379
3380 end_of_parse_external_declaration:
3381         assert(scope == &declaration->scope);
3382         set_scope(last_scope);
3383         environment_pop_to(top);
3384 }
3385
3386 static type_t *make_bitfield_type(type_t *base, expression_t *size,
3387                                   source_position_t source_position)
3388 {
3389         type_t *type        = allocate_type_zero(TYPE_BITFIELD, source_position);
3390         type->bitfield.base = base;
3391         type->bitfield.size = size;
3392
3393         return type;
3394 }
3395
3396 static declaration_t *find_compound_entry(declaration_t *compound_declaration,
3397                                           symbol_t *symbol)
3398 {
3399         declaration_t *iter = compound_declaration->scope.declarations;
3400         for( ; iter != NULL; iter = iter->next) {
3401                 if(iter->namespc != NAMESPACE_NORMAL)
3402                         continue;
3403
3404                 if(iter->symbol == NULL) {
3405                         type_t *type = skip_typeref(iter->type);
3406                         if(is_type_compound(type)) {
3407                                 declaration_t *result
3408                                         = find_compound_entry(type->compound.declaration, symbol);
3409                                 if(result != NULL)
3410                                         return result;
3411                         }
3412                         continue;
3413                 }
3414
3415                 if(iter->symbol == symbol) {
3416                         return iter;
3417                 }
3418         }
3419
3420         return NULL;
3421 }
3422
3423 static void parse_compound_declarators(declaration_t *struct_declaration,
3424                 const declaration_specifiers_t *specifiers)
3425 {
3426         declaration_t *last_declaration = struct_declaration->scope.declarations;
3427         if(last_declaration != NULL) {
3428                 while(last_declaration->next != NULL) {
3429                         last_declaration = last_declaration->next;
3430                 }
3431         }
3432
3433         while(1) {
3434                 declaration_t *declaration;
3435
3436                 if(token.type == ':') {
3437                         source_position_t source_position = HERE;
3438                         next_token();
3439
3440                         type_t *base_type = specifiers->type;
3441                         expression_t *size = parse_constant_expression();
3442
3443                         if(!is_type_integer(skip_typeref(base_type))) {
3444                                 errorf(HERE, "bitfield base type '%T' is not an integer type",
3445                                        base_type);
3446                         }
3447
3448                         type_t *type = make_bitfield_type(base_type, size, source_position);
3449
3450                         declaration                         = allocate_declaration_zero();
3451                         declaration->namespc                = NAMESPACE_NORMAL;
3452                         declaration->declared_storage_class = STORAGE_CLASS_NONE;
3453                         declaration->storage_class          = STORAGE_CLASS_NONE;
3454                         declaration->source_position        = source_position;
3455                         declaration->modifiers              = specifiers->decl_modifiers;
3456                         declaration->type                   = type;
3457                 } else {
3458                         declaration = parse_declarator(specifiers,/*may_be_abstract=*/true);
3459
3460                         type_t *orig_type = declaration->type;
3461                         type_t *type      = skip_typeref(orig_type);
3462
3463                         if(token.type == ':') {
3464                                 source_position_t source_position = HERE;
3465                                 next_token();
3466                                 expression_t *size = parse_constant_expression();
3467
3468                                 if(!is_type_integer(type)) {
3469                                         errorf(HERE, "bitfield base type '%T' is not an "
3470                                                "integer type", orig_type);
3471                                 }
3472
3473                                 type_t *bitfield_type = make_bitfield_type(orig_type, size, source_position);
3474                                 declaration->type = bitfield_type;
3475                         } else {
3476                                 /* TODO we ignore arrays for now... what is missing is a check
3477                                  * that they're at the end of the struct */
3478                                 if(is_type_incomplete(type) && !is_type_array(type)) {
3479                                         errorf(HERE,
3480                                                "compound member '%Y' has incomplete type '%T'",
3481                                                declaration->symbol, orig_type);
3482                                 } else if(is_type_function(type)) {
3483                                         errorf(HERE, "compound member '%Y' must not have function "
3484                                                "type '%T'", declaration->symbol, orig_type);
3485                                 }
3486                         }
3487                 }
3488
3489                 /* make sure we don't define a symbol multiple times */
3490                 symbol_t *symbol = declaration->symbol;
3491                 if(symbol != NULL) {
3492                         declaration_t *prev_decl
3493                                 = find_compound_entry(struct_declaration, symbol);
3494
3495                         if(prev_decl != NULL) {
3496                                 assert(prev_decl->symbol == symbol);
3497                                 errorf(declaration->source_position,
3498                                        "multiple declarations of symbol '%Y'", symbol);
3499                                 errorf(prev_decl->source_position,
3500                                        "previous declaration of '%Y' was here", symbol);
3501                         }
3502                 }
3503
3504                 /* append declaration */
3505                 if(last_declaration != NULL) {
3506                         last_declaration->next = declaration;
3507                 } else {
3508                         struct_declaration->scope.declarations = declaration;
3509                 }
3510                 last_declaration = declaration;
3511
3512                 if(token.type != ',')
3513                         break;
3514                 next_token();
3515         }
3516         expect(';');
3517
3518 end_error:
3519         ;
3520 }
3521
3522 static void parse_compound_type_entries(declaration_t *compound_declaration)
3523 {
3524         eat('{');
3525
3526         while(token.type != '}' && token.type != T_EOF) {
3527                 declaration_specifiers_t specifiers;
3528                 memset(&specifiers, 0, sizeof(specifiers));
3529                 parse_declaration_specifiers(&specifiers);
3530
3531                 parse_compound_declarators(compound_declaration, &specifiers);
3532         }
3533         if(token.type == T_EOF) {
3534                 errorf(HERE, "EOF while parsing struct");
3535         }
3536         next_token();
3537 }
3538
3539 static type_t *parse_typename(void)
3540 {
3541         declaration_specifiers_t specifiers;
3542         memset(&specifiers, 0, sizeof(specifiers));
3543         parse_declaration_specifiers(&specifiers);
3544         if(specifiers.declared_storage_class != STORAGE_CLASS_NONE) {
3545                 /* TODO: improve error message, user does probably not know what a
3546                  * storage class is...
3547                  */
3548                 errorf(HERE, "typename may not have a storage class");
3549         }
3550
3551         type_t *result = parse_abstract_declarator(specifiers.type);
3552
3553         return result;
3554 }
3555
3556
3557
3558
3559 typedef expression_t* (*parse_expression_function) (unsigned precedence);
3560 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
3561                                                           expression_t *left);
3562
3563 typedef struct expression_parser_function_t expression_parser_function_t;
3564 struct expression_parser_function_t {
3565         unsigned                         precedence;
3566         parse_expression_function        parser;
3567         unsigned                         infix_precedence;
3568         parse_expression_infix_function  infix_parser;
3569 };
3570
3571 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
3572
3573 /**
3574  * Creates a new invalid expression.
3575  */
3576 static expression_t *create_invalid_expression(void)
3577 {
3578         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
3579         expression->base.source_position = token.source_position;
3580         return expression;
3581 }
3582
3583 /**
3584  * Prints an error message if an expression was expected but not read
3585  */
3586 static expression_t *expected_expression_error(void)
3587 {
3588         /* skip the error message if the error token was read */
3589         if (token.type != T_ERROR) {
3590                 errorf(HERE, "expected expression, got token '%K'", &token);
3591         }
3592         next_token();
3593
3594         return create_invalid_expression();
3595 }
3596
3597 /**
3598  * Parse a string constant.
3599  */
3600 static expression_t *parse_string_const(void)
3601 {
3602         wide_string_t wres;
3603         if (token.type == T_STRING_LITERAL) {
3604                 string_t res = token.v.string;
3605                 next_token();
3606                 while (token.type == T_STRING_LITERAL) {
3607                         res = concat_strings(&res, &token.v.string);
3608                         next_token();
3609                 }
3610                 if (token.type != T_WIDE_STRING_LITERAL) {
3611                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
3612                         /* note: that we use type_char_ptr here, which is already the
3613                          * automatic converted type. revert_automatic_type_conversion
3614                          * will construct the array type */
3615                         cnst->base.type    = type_char_ptr;
3616                         cnst->string.value = res;
3617                         return cnst;
3618                 }
3619
3620                 wres = concat_string_wide_string(&res, &token.v.wide_string);
3621         } else {
3622                 wres = token.v.wide_string;
3623         }
3624         next_token();
3625
3626         for (;;) {
3627                 switch (token.type) {
3628                         case T_WIDE_STRING_LITERAL:
3629                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
3630                                 break;
3631
3632                         case T_STRING_LITERAL:
3633                                 wres = concat_wide_string_string(&wres, &token.v.string);
3634                                 break;
3635
3636                         default: {
3637                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
3638                                 cnst->base.type         = type_wchar_t_ptr;
3639                                 cnst->wide_string.value = wres;
3640                                 return cnst;
3641                         }
3642                 }
3643                 next_token();
3644         }
3645 }
3646
3647 /**
3648  * Parse an integer constant.
3649  */
3650 static expression_t *parse_int_const(void)
3651 {
3652         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
3653         cnst->base.source_position = HERE;
3654         cnst->base.type            = token.datatype;
3655         cnst->conste.v.int_value   = token.v.intvalue;
3656
3657         next_token();
3658
3659         return cnst;
3660 }
3661
3662 /**
3663  * Parse a character constant.
3664  */
3665 static expression_t *parse_character_constant(void)
3666 {
3667         expression_t *cnst = allocate_expression_zero(EXPR_CHARACTER_CONSTANT);
3668
3669         cnst->base.source_position = HERE;
3670         cnst->base.type            = token.datatype;
3671         cnst->conste.v.character   = token.v.string;
3672
3673         if (cnst->conste.v.character.size != 1) {
3674                 if (warning.multichar && (c_mode & _GNUC)) {
3675                         /* TODO */
3676                         warningf(HERE, "multi-character character constant");
3677                 } else {
3678                         errorf(HERE, "more than 1 characters in character constant");
3679                 }
3680         }
3681         next_token();
3682
3683         return cnst;
3684 }
3685
3686 /**
3687  * Parse a wide character constant.
3688  */
3689 static expression_t *parse_wide_character_constant(void)
3690 {
3691         expression_t *cnst = allocate_expression_zero(EXPR_WIDE_CHARACTER_CONSTANT);
3692
3693         cnst->base.source_position    = HERE;
3694         cnst->base.type               = token.datatype;
3695         cnst->conste.v.wide_character = token.v.wide_string;
3696
3697         if (cnst->conste.v.wide_character.size != 1) {
3698                 if (warning.multichar && (c_mode & _GNUC)) {
3699                         /* TODO */
3700                         warningf(HERE, "multi-character character constant");
3701                 } else {
3702                         errorf(HERE, "more than 1 characters in character constant");
3703                 }
3704         }
3705         next_token();
3706
3707         return cnst;
3708 }
3709
3710 /**
3711  * Parse a float constant.
3712  */
3713 static expression_t *parse_float_const(void)
3714 {
3715         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
3716         cnst->base.type            = token.datatype;
3717         cnst->conste.v.float_value = token.v.floatvalue;
3718
3719         next_token();
3720
3721         return cnst;
3722 }
3723
3724 static declaration_t *create_implicit_function(symbol_t *symbol,
3725                 const source_position_t source_position)
3726 {
3727         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION, source_position);
3728         ntype->function.return_type            = type_int;
3729         ntype->function.unspecified_parameters = true;
3730
3731         type_t *type = typehash_insert(ntype);
3732         if(type != ntype) {
3733                 free_type(ntype);
3734         }
3735
3736         declaration_t *const declaration    = allocate_declaration_zero();
3737         declaration->storage_class          = STORAGE_CLASS_EXTERN;
3738         declaration->declared_storage_class = STORAGE_CLASS_EXTERN;
3739         declaration->type                   = type;
3740         declaration->symbol                 = symbol;
3741         declaration->source_position        = source_position;
3742         declaration->parent_scope           = global_scope;
3743
3744         scope_t *old_scope = scope;
3745         set_scope(global_scope);
3746
3747         environment_push(declaration);
3748         /* prepends the declaration to the global declarations list */
3749         declaration->next   = scope->declarations;
3750         scope->declarations = declaration;
3751
3752         assert(scope == global_scope);
3753         set_scope(old_scope);
3754
3755         return declaration;
3756 }
3757
3758 /**
3759  * Creates a return_type (func)(argument_type) function type if not
3760  * already exists.
3761  *
3762  * @param return_type    the return type
3763  * @param argument_type  the argument type
3764  */
3765 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
3766 {
3767         function_parameter_t *parameter
3768                 = obstack_alloc(type_obst, sizeof(parameter[0]));
3769         memset(parameter, 0, sizeof(parameter[0]));
3770         parameter->type = argument_type;
3771
3772         type_t *type               = allocate_type_zero(TYPE_FUNCTION, builtin_source_position);
3773         type->function.return_type = return_type;
3774         type->function.parameters  = parameter;
3775
3776         type_t *result = typehash_insert(type);
3777         if(result != type) {
3778                 free_type(type);
3779         }
3780
3781         return result;
3782 }
3783
3784 /**
3785  * Creates a function type for some function like builtins.
3786  *
3787  * @param symbol   the symbol describing the builtin
3788  */
3789 static type_t *get_builtin_symbol_type(symbol_t *symbol)
3790 {
3791         switch(symbol->ID) {
3792         case T___builtin_alloca:
3793                 return make_function_1_type(type_void_ptr, type_size_t);
3794         case T___builtin_nan:
3795                 return make_function_1_type(type_double, type_char_ptr);
3796         case T___builtin_nanf:
3797                 return make_function_1_type(type_float, type_char_ptr);
3798         case T___builtin_nand:
3799                 return make_function_1_type(type_long_double, type_char_ptr);
3800         case T___builtin_va_end:
3801                 return make_function_1_type(type_void, type_valist);
3802         default:
3803                 panic("not implemented builtin symbol found");
3804         }
3805 }
3806
3807 /**
3808  * Performs automatic type cast as described in § 6.3.2.1.
3809  *
3810  * @param orig_type  the original type
3811  */
3812 static type_t *automatic_type_conversion(type_t *orig_type)
3813 {
3814         type_t *type = skip_typeref(orig_type);
3815         if(is_type_array(type)) {
3816                 array_type_t *array_type   = &type->array;
3817                 type_t       *element_type = array_type->element_type;
3818                 unsigned      qualifiers   = array_type->type.qualifiers;
3819
3820                 return make_pointer_type(element_type, qualifiers);
3821         }
3822
3823         if(is_type_function(type)) {
3824                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3825         }
3826
3827         return orig_type;
3828 }
3829
3830 /**
3831  * reverts the automatic casts of array to pointer types and function
3832  * to function-pointer types as defined § 6.3.2.1
3833  */
3834 type_t *revert_automatic_type_conversion(const expression_t *expression)
3835 {
3836         switch (expression->kind) {
3837                 case EXPR_REFERENCE: return expression->reference.declaration->type;
3838                 case EXPR_SELECT:    return expression->select.compound_entry->type;
3839
3840                 case EXPR_UNARY_DEREFERENCE: {
3841                         const expression_t *const value = expression->unary.value;
3842                         type_t             *const type  = skip_typeref(value->base.type);
3843                         assert(is_type_pointer(type));
3844                         return type->pointer.points_to;
3845                 }
3846
3847                 case EXPR_BUILTIN_SYMBOL:
3848                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
3849
3850                 case EXPR_ARRAY_ACCESS: {
3851                         const expression_t *array_ref = expression->array_access.array_ref;
3852                         type_t             *type_left = skip_typeref(array_ref->base.type);
3853                         if (!is_type_valid(type_left))
3854                                 return type_left;
3855                         assert(is_type_pointer(type_left));
3856                         return type_left->pointer.points_to;
3857                 }
3858
3859                 case EXPR_STRING_LITERAL: {
3860                         size_t size = expression->string.value.size;
3861                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
3862                 }
3863
3864                 case EXPR_WIDE_STRING_LITERAL: {
3865                         size_t size = expression->wide_string.value.size;
3866                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
3867                 }
3868
3869                 case EXPR_COMPOUND_LITERAL:
3870                         return expression->compound_literal.type;
3871
3872                 default: break;
3873         }
3874
3875         return expression->base.type;
3876 }
3877
3878 static expression_t *parse_reference(void)
3879 {
3880         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
3881
3882         reference_expression_t *ref = &expression->reference;
3883         ref->symbol = token.v.symbol;
3884
3885         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
3886
3887         source_position_t source_position = token.source_position;
3888         next_token();
3889
3890         if(declaration == NULL) {
3891                 if (! strict_mode && token.type == '(') {
3892                         /* an implicitly defined function */
3893                         if (warning.implicit_function_declaration) {
3894                                 warningf(HERE, "implicit declaration of function '%Y'",
3895                                         ref->symbol);
3896                         }
3897
3898                         declaration = create_implicit_function(ref->symbol,
3899                                                                source_position);
3900                 } else {
3901                         errorf(HERE, "unknown symbol '%Y' found.", ref->symbol);
3902                         return create_invalid_expression();
3903                 }
3904         }
3905
3906         type_t *type         = declaration->type;
3907
3908         /* we always do the auto-type conversions; the & and sizeof parser contains
3909          * code to revert this! */
3910         type = automatic_type_conversion(type);
3911
3912         ref->declaration = declaration;
3913         ref->base.type   = type;
3914
3915         /* this declaration is used */
3916         declaration->used = true;
3917
3918         return expression;
3919 }
3920
3921 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
3922 {
3923         (void) expression;
3924         (void) dest_type;
3925         /* TODO check if explicit cast is allowed and issue warnings/errors */
3926 }
3927
3928 static expression_t *parse_compound_literal(type_t *type)
3929 {
3930         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
3931
3932         parse_initializer_env_t env;
3933         env.type             = type;
3934         env.declaration      = NULL;
3935         env.must_be_constant = false;
3936         initializer_t *initializer = parse_initializer(&env);
3937         type = env.type;
3938
3939         expression->compound_literal.initializer = initializer;
3940         expression->compound_literal.type        = type;
3941         expression->base.type                    = automatic_type_conversion(type);
3942
3943         return expression;
3944 }
3945
3946 /**
3947  * Parse a cast expression.
3948  */
3949 static expression_t *parse_cast(void)
3950 {
3951         source_position_t source_position = token.source_position;
3952
3953         type_t *type  = parse_typename();
3954
3955         expect(')');
3956
3957         if(token.type == '{') {
3958                 return parse_compound_literal(type);
3959         }
3960
3961         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
3962         cast->base.source_position = source_position;
3963
3964         expression_t *value = parse_sub_expression(20);
3965
3966         check_cast_allowed(value, type);
3967
3968         cast->base.type   = type;
3969         cast->unary.value = value;
3970
3971         return cast;
3972 end_error:
3973         return create_invalid_expression();
3974 }
3975
3976 /**
3977  * Parse a statement expression.
3978  */
3979 static expression_t *parse_statement_expression(void)
3980 {
3981         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
3982
3983         statement_t *statement           = parse_compound_statement();
3984         expression->statement.statement  = statement;
3985         expression->base.source_position = statement->base.source_position;
3986
3987         /* find last statement and use its type */
3988         type_t *type = type_void;
3989         const statement_t *stmt = statement->compound.statements;
3990         if (stmt != NULL) {
3991                 while (stmt->base.next != NULL)
3992                         stmt = stmt->base.next;
3993
3994                 if (stmt->kind == STATEMENT_EXPRESSION) {
3995                         type = stmt->expression.expression->base.type;
3996                 }
3997         } else {
3998                 warningf(expression->base.source_position, "empty statement expression ({})");
3999         }
4000         expression->base.type = type;
4001
4002         expect(')');
4003
4004         return expression;
4005 end_error:
4006         return create_invalid_expression();
4007 }
4008
4009 /**
4010  * Parse a braced expression.
4011  */
4012 static expression_t *parse_brace_expression(void)
4013 {
4014         eat('(');
4015
4016         switch(token.type) {
4017         case '{':
4018                 /* gcc extension: a statement expression */
4019                 return parse_statement_expression();
4020
4021         TYPE_QUALIFIERS
4022         TYPE_SPECIFIERS
4023                 return parse_cast();
4024         case T_IDENTIFIER:
4025                 if(is_typedef_symbol(token.v.symbol)) {
4026                         return parse_cast();
4027                 }
4028         }
4029
4030         expression_t *result = parse_expression();
4031         expect(')');
4032
4033         return result;
4034 end_error:
4035         return create_invalid_expression();
4036 }
4037
4038 static expression_t *parse_function_keyword(void)
4039 {
4040         next_token();
4041         /* TODO */
4042
4043         if (current_function == NULL) {
4044                 errorf(HERE, "'__func__' used outside of a function");
4045         }
4046
4047         expression_t *expression = allocate_expression_zero(EXPR_FUNCTION);
4048         expression->base.type    = type_char_ptr;
4049
4050         return expression;
4051 }
4052
4053 static expression_t *parse_pretty_function_keyword(void)
4054 {
4055         eat(T___PRETTY_FUNCTION__);
4056         /* TODO */
4057
4058         if (current_function == NULL) {
4059                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
4060         }
4061
4062         expression_t *expression = allocate_expression_zero(EXPR_PRETTY_FUNCTION);
4063         expression->base.type    = type_char_ptr;
4064
4065         return expression;
4066 }
4067
4068 static designator_t *parse_designator(void)
4069 {
4070         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
4071         result->source_position = HERE;
4072
4073         if(token.type != T_IDENTIFIER) {
4074                 parse_error_expected("while parsing member designator",
4075                                      T_IDENTIFIER, 0);
4076                 eat_paren();
4077                 return NULL;
4078         }
4079         result->symbol = token.v.symbol;
4080         next_token();
4081
4082         designator_t *last_designator = result;
4083         while(true) {
4084                 if(token.type == '.') {
4085                         next_token();
4086                         if(token.type != T_IDENTIFIER) {
4087                                 parse_error_expected("while parsing member designator",
4088                                                      T_IDENTIFIER, 0);
4089                                 eat_paren();
4090                                 return NULL;
4091                         }
4092                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
4093                         designator->source_position = HERE;
4094                         designator->symbol          = token.v.symbol;
4095                         next_token();
4096
4097                         last_designator->next = designator;
4098                         last_designator       = designator;
4099                         continue;
4100                 }
4101                 if(token.type == '[') {
4102                         next_token();
4103                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
4104                         designator->source_position = HERE;
4105                         designator->array_index     = parse_expression();
4106                         if(designator->array_index == NULL) {
4107                                 eat_paren();
4108                                 return NULL;
4109                         }
4110                         expect(']');
4111
4112                         last_designator->next = designator;
4113                         last_designator       = designator;
4114                         continue;
4115                 }
4116                 break;
4117         }
4118
4119         return result;
4120 end_error:
4121         return NULL;
4122 }
4123
4124 /**
4125  * Parse the __builtin_offsetof() expression.
4126  */
4127 static expression_t *parse_offsetof(void)
4128 {
4129         eat(T___builtin_offsetof);
4130
4131         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
4132         expression->base.type    = type_size_t;
4133
4134         expect('(');
4135         type_t *type = parse_typename();
4136         expect(',');
4137         designator_t *designator = parse_designator();
4138         expect(')');
4139
4140         expression->offsetofe.type       = type;
4141         expression->offsetofe.designator = designator;
4142
4143         type_path_t path;
4144         memset(&path, 0, sizeof(path));
4145         path.top_type = type;
4146         path.path     = NEW_ARR_F(type_path_entry_t, 0);
4147
4148         descend_into_subtype(&path);
4149
4150         if(!walk_designator(&path, designator, true)) {
4151                 return create_invalid_expression();
4152         }
4153
4154         DEL_ARR_F(path.path);
4155
4156         return expression;
4157 end_error:
4158         return create_invalid_expression();
4159 }
4160
4161 /**
4162  * Parses a _builtin_va_start() expression.
4163  */
4164 static expression_t *parse_va_start(void)
4165 {
4166         eat(T___builtin_va_start);
4167
4168         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
4169
4170         expect('(');
4171         expression->va_starte.ap = parse_assignment_expression();
4172         expect(',');
4173         expression_t *const expr = parse_assignment_expression();
4174         if (expr->kind == EXPR_REFERENCE) {
4175                 declaration_t *const decl = expr->reference.declaration;
4176                 if (decl == NULL)
4177                         return create_invalid_expression();
4178                 if (decl->parent_scope == &current_function->scope &&
4179                     decl->next == NULL) {
4180                         expression->va_starte.parameter = decl;
4181                         expect(')');
4182                         return expression;
4183                 }
4184         }
4185         errorf(expr->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
4186 end_error:
4187         return create_invalid_expression();
4188 }
4189
4190 /**
4191  * Parses a _builtin_va_arg() expression.
4192  */
4193 static expression_t *parse_va_arg(void)
4194 {
4195         eat(T___builtin_va_arg);
4196
4197         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
4198
4199         expect('(');
4200         expression->va_arge.ap = parse_assignment_expression();
4201         expect(',');
4202         expression->base.type = parse_typename();
4203         expect(')');
4204
4205         return expression;
4206 end_error:
4207         return create_invalid_expression();
4208 }
4209
4210 static expression_t *parse_builtin_symbol(void)
4211 {
4212         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
4213
4214         symbol_t *symbol = token.v.symbol;
4215
4216         expression->builtin_symbol.symbol = symbol;
4217         next_token();
4218
4219         type_t *type = get_builtin_symbol_type(symbol);
4220         type = automatic_type_conversion(type);
4221
4222         expression->base.type = type;
4223         return expression;
4224 }
4225
4226 /**
4227  * Parses a __builtin_constant() expression.
4228  */
4229 static expression_t *parse_builtin_constant(void)
4230 {
4231         eat(T___builtin_constant_p);
4232
4233         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
4234
4235         expect('(');
4236         expression->builtin_constant.value = parse_assignment_expression();
4237         expect(')');
4238         expression->base.type = type_int;
4239
4240         return expression;
4241 end_error:
4242         return create_invalid_expression();
4243 }
4244
4245 /**
4246  * Parses a __builtin_prefetch() expression.
4247  */
4248 static expression_t *parse_builtin_prefetch(void)
4249 {
4250         eat(T___builtin_prefetch);
4251
4252         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
4253
4254         expect('(');
4255         expression->builtin_prefetch.adr = parse_assignment_expression();
4256         if (token.type == ',') {
4257                 next_token();
4258                 expression->builtin_prefetch.rw = parse_assignment_expression();
4259         }
4260         if (token.type == ',') {
4261                 next_token();
4262                 expression->builtin_prefetch.locality = parse_assignment_expression();
4263         }
4264         expect(')');
4265         expression->base.type = type_void;
4266
4267         return expression;
4268 end_error:
4269         return create_invalid_expression();
4270 }
4271
4272 /**
4273  * Parses a __builtin_is_*() compare expression.
4274  */
4275 static expression_t *parse_compare_builtin(void)
4276 {
4277         expression_t *expression;
4278
4279         switch(token.type) {
4280         case T___builtin_isgreater:
4281                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
4282                 break;
4283         case T___builtin_isgreaterequal:
4284                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
4285                 break;
4286         case T___builtin_isless:
4287                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
4288                 break;
4289         case T___builtin_islessequal:
4290                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
4291                 break;
4292         case T___builtin_islessgreater:
4293                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
4294                 break;
4295         case T___builtin_isunordered:
4296                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
4297                 break;
4298         default:
4299                 panic("invalid compare builtin found");
4300                 break;
4301         }
4302         expression->base.source_position = HERE;
4303         next_token();
4304
4305         expect('(');
4306         expression->binary.left = parse_assignment_expression();
4307         expect(',');
4308         expression->binary.right = parse_assignment_expression();
4309         expect(')');
4310
4311         type_t *const orig_type_left  = expression->binary.left->base.type;
4312         type_t *const orig_type_right = expression->binary.right->base.type;
4313
4314         type_t *const type_left  = skip_typeref(orig_type_left);
4315         type_t *const type_right = skip_typeref(orig_type_right);
4316         if(!is_type_float(type_left) && !is_type_float(type_right)) {
4317                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4318                         type_error_incompatible("invalid operands in comparison",
4319                                 expression->base.source_position, orig_type_left, orig_type_right);
4320                 }
4321         } else {
4322                 semantic_comparison(&expression->binary);
4323         }
4324
4325         return expression;
4326 end_error:
4327         return create_invalid_expression();
4328 }
4329
4330 /**
4331  * Parses a __builtin_expect() expression.
4332  */
4333 static expression_t *parse_builtin_expect(void)
4334 {
4335         eat(T___builtin_expect);
4336
4337         expression_t *expression
4338                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
4339
4340         expect('(');
4341         expression->binary.left = parse_assignment_expression();
4342         expect(',');
4343         expression->binary.right = parse_constant_expression();
4344         expect(')');
4345
4346         expression->base.type = expression->binary.left->base.type;
4347
4348         return expression;
4349 end_error:
4350         return create_invalid_expression();
4351 }
4352
4353 /**
4354  * Parses a MS assume() expression.
4355  */
4356 static expression_t *parse_assume(void) {
4357         eat(T_assume);
4358
4359         expression_t *expression
4360                 = allocate_expression_zero(EXPR_UNARY_ASSUME);
4361
4362         expect('(');
4363         expression->unary.value = parse_assignment_expression();
4364         expect(')');
4365
4366         expression->base.type = type_void;
4367         return expression;
4368 end_error:
4369         return create_invalid_expression();
4370 }
4371
4372 /**
4373  * Parses a primary expression.
4374  */
4375 static expression_t *parse_primary_expression(void)
4376 {
4377         switch (token.type) {
4378                 case T_INTEGER:                  return parse_int_const();
4379                 case T_CHARACTER_CONSTANT:       return parse_character_constant();
4380                 case T_WIDE_CHARACTER_CONSTANT:  return parse_wide_character_constant();
4381                 case T_FLOATINGPOINT:            return parse_float_const();
4382                 case T_STRING_LITERAL:
4383                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
4384                 case T_IDENTIFIER:               return parse_reference();
4385                 case T___FUNCTION__:
4386                 case T___func__:                 return parse_function_keyword();
4387                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
4388                 case T___builtin_offsetof:       return parse_offsetof();
4389                 case T___builtin_va_start:       return parse_va_start();
4390                 case T___builtin_va_arg:         return parse_va_arg();
4391                 case T___builtin_expect:         return parse_builtin_expect();
4392                 case T___builtin_alloca:
4393                 case T___builtin_nan:
4394                 case T___builtin_nand:
4395                 case T___builtin_nanf:
4396                 case T___builtin_va_end:         return parse_builtin_symbol();
4397                 case T___builtin_isgreater:
4398                 case T___builtin_isgreaterequal:
4399                 case T___builtin_isless:
4400                 case T___builtin_islessequal:
4401                 case T___builtin_islessgreater:
4402                 case T___builtin_isunordered:    return parse_compare_builtin();
4403                 case T___builtin_constant_p:     return parse_builtin_constant();
4404                 case T___builtin_prefetch:       return parse_builtin_prefetch();
4405                 case T_assume:                   return parse_assume();
4406
4407                 case '(':                        return parse_brace_expression();
4408         }
4409
4410         errorf(HERE, "unexpected token %K, expected an expression", &token);
4411         eat_statement();
4412
4413         return create_invalid_expression();
4414 }
4415
4416 /**
4417  * Check if the expression has the character type and issue a warning then.
4418  */
4419 static void check_for_char_index_type(const expression_t *expression) {
4420         type_t       *const type      = expression->base.type;
4421         const type_t *const base_type = skip_typeref(type);
4422
4423         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
4424                         warning.char_subscripts) {
4425                 warningf(expression->base.source_position,
4426                         "array subscript has type '%T'", type);
4427         }
4428 }
4429
4430 static expression_t *parse_array_expression(unsigned precedence,
4431                                             expression_t *left)
4432 {
4433         (void) precedence;
4434
4435         eat('[');
4436
4437         expression_t *inside = parse_expression();
4438
4439         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
4440
4441         array_access_expression_t *array_access = &expression->array_access;
4442
4443         type_t *const orig_type_left   = left->base.type;
4444         type_t *const orig_type_inside = inside->base.type;
4445
4446         type_t *const type_left   = skip_typeref(orig_type_left);
4447         type_t *const type_inside = skip_typeref(orig_type_inside);
4448
4449         type_t *return_type;
4450         if (is_type_pointer(type_left)) {
4451                 return_type             = type_left->pointer.points_to;
4452                 array_access->array_ref = left;
4453                 array_access->index     = inside;
4454                 check_for_char_index_type(inside);
4455         } else if (is_type_pointer(type_inside)) {
4456                 return_type             = type_inside->pointer.points_to;
4457                 array_access->array_ref = inside;
4458                 array_access->index     = left;
4459                 array_access->flipped   = true;
4460                 check_for_char_index_type(left);
4461         } else {
4462                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
4463                         errorf(HERE,
4464                                 "array access on object with non-pointer types '%T', '%T'",
4465                                 orig_type_left, orig_type_inside);
4466                 }
4467                 return_type             = type_error_type;
4468                 array_access->array_ref = create_invalid_expression();
4469         }
4470
4471         if(token.type != ']') {
4472                 parse_error_expected("Problem while parsing array access", ']', 0);
4473                 return expression;
4474         }
4475         next_token();
4476
4477         return_type           = automatic_type_conversion(return_type);
4478         expression->base.type = return_type;
4479
4480         return expression;
4481 }
4482
4483 static expression_t *parse_typeprop(expression_kind_t kind, unsigned precedence)
4484 {
4485         expression_t *tp_expression = allocate_expression_zero(kind);
4486         tp_expression->base.type    = type_size_t;
4487
4488         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
4489                 next_token();
4490                 tp_expression->typeprop.type = parse_typename();
4491                 expect(')');
4492         } else {
4493                 expression_t *expression = parse_sub_expression(precedence);
4494                 expression->base.type    = revert_automatic_type_conversion(expression);
4495
4496                 tp_expression->typeprop.type          = expression->base.type;
4497                 tp_expression->typeprop.tp_expression = expression;
4498         }
4499
4500         return tp_expression;
4501 end_error:
4502         return create_invalid_expression();
4503 }
4504
4505 static expression_t *parse_sizeof(unsigned precedence)
4506 {
4507         eat(T_sizeof);
4508         return parse_typeprop(EXPR_SIZEOF, precedence);
4509 }
4510
4511 static expression_t *parse_alignof(unsigned precedence)
4512 {
4513         eat(T___alignof__);
4514         return parse_typeprop(EXPR_SIZEOF, precedence);
4515 }
4516
4517 static expression_t *parse_select_expression(unsigned precedence,
4518                                              expression_t *compound)
4519 {
4520         (void) precedence;
4521         assert(token.type == '.' || token.type == T_MINUSGREATER);
4522
4523         bool is_pointer = (token.type == T_MINUSGREATER);
4524         next_token();
4525
4526         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
4527         select->select.compound = compound;
4528
4529         if(token.type != T_IDENTIFIER) {
4530                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
4531                 return select;
4532         }
4533         symbol_t *symbol      = token.v.symbol;
4534         select->select.symbol = symbol;
4535         next_token();
4536
4537         type_t *const orig_type = compound->base.type;
4538         type_t *const type      = skip_typeref(orig_type);
4539
4540         type_t *type_left = type;
4541         if(is_pointer) {
4542                 if (!is_type_pointer(type)) {
4543                         if (is_type_valid(type)) {
4544                                 errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
4545                         }
4546                         return create_invalid_expression();
4547                 }
4548                 type_left = type->pointer.points_to;
4549         }
4550         type_left = skip_typeref(type_left);
4551
4552         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
4553             type_left->kind != TYPE_COMPOUND_UNION) {
4554                 if (is_type_valid(type_left)) {
4555                         errorf(HERE, "request for member '%Y' in something not a struct or "
4556                                "union, but '%T'", symbol, type_left);
4557                 }
4558                 return create_invalid_expression();
4559         }
4560
4561         declaration_t *const declaration = type_left->compound.declaration;
4562
4563         if(!declaration->init.is_defined) {
4564                 errorf(HERE, "request for member '%Y' of incomplete type '%T'",
4565                        symbol, type_left);
4566                 return create_invalid_expression();
4567         }
4568
4569         declaration_t *iter = find_compound_entry(declaration, symbol);
4570         if(iter == NULL) {
4571                 errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
4572                 return create_invalid_expression();
4573         }
4574
4575         /* we always do the auto-type conversions; the & and sizeof parser contains
4576          * code to revert this! */
4577         type_t *expression_type = automatic_type_conversion(iter->type);
4578
4579         select->select.compound_entry = iter;
4580         select->base.type             = expression_type;
4581
4582         if(expression_type->kind == TYPE_BITFIELD) {
4583                 expression_t *extract
4584                         = allocate_expression_zero(EXPR_UNARY_BITFIELD_EXTRACT);
4585                 extract->unary.value = select;
4586                 extract->base.type   = expression_type->bitfield.base;
4587
4588                 return extract;
4589         }
4590
4591         return select;
4592 }
4593
4594 /**
4595  * Parse a call expression, ie. expression '( ... )'.
4596  *
4597  * @param expression  the function address
4598  */
4599 static expression_t *parse_call_expression(unsigned precedence,
4600                                            expression_t *expression)
4601 {
4602         (void) precedence;
4603         expression_t *result = allocate_expression_zero(EXPR_CALL);
4604
4605         call_expression_t *call = &result->call;
4606         call->function          = expression;
4607
4608         type_t *const orig_type = expression->base.type;
4609         type_t *const type      = skip_typeref(orig_type);
4610
4611         function_type_t *function_type = NULL;
4612         if (is_type_pointer(type)) {
4613                 type_t *const to_type = skip_typeref(type->pointer.points_to);
4614
4615                 if (is_type_function(to_type)) {
4616                         function_type   = &to_type->function;
4617                         call->base.type = function_type->return_type;
4618                 }
4619         }
4620
4621         if (function_type == NULL && is_type_valid(type)) {
4622                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
4623         }
4624
4625         /* parse arguments */
4626         eat('(');
4627
4628         if(token.type != ')') {
4629                 call_argument_t *last_argument = NULL;
4630
4631                 while(true) {
4632                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
4633
4634                         argument->expression = parse_assignment_expression();
4635                         if(last_argument == NULL) {
4636                                 call->arguments = argument;
4637                         } else {
4638                                 last_argument->next = argument;
4639                         }
4640                         last_argument = argument;
4641
4642                         if(token.type != ',')
4643                                 break;
4644                         next_token();
4645                 }
4646         }
4647         expect(')');
4648
4649         if(function_type != NULL) {
4650                 function_parameter_t *parameter = function_type->parameters;
4651                 call_argument_t      *argument  = call->arguments;
4652                 for( ; parameter != NULL && argument != NULL;
4653                                 parameter = parameter->next, argument = argument->next) {
4654                         type_t *expected_type = parameter->type;
4655                         /* TODO report scope in error messages */
4656                         expression_t *const arg_expr = argument->expression;
4657                         type_t       *const res_type = semantic_assign(expected_type, arg_expr, "function call");
4658                         if (res_type == NULL) {
4659                                 /* TODO improve error message */
4660                                 errorf(arg_expr->base.source_position,
4661                                         "Cannot call function with argument '%E' of type '%T' where type '%T' is expected",
4662                                         arg_expr, arg_expr->base.type, expected_type);
4663                         } else {
4664                                 argument->expression = create_implicit_cast(argument->expression, expected_type);
4665                         }
4666                 }
4667                 /* too few parameters */
4668                 if(parameter != NULL) {
4669                         errorf(HERE, "too few arguments to function '%E'", expression);
4670                 } else if(argument != NULL) {
4671                         /* too many parameters */
4672                         if(!function_type->variadic
4673                                         && !function_type->unspecified_parameters) {
4674                                 errorf(HERE, "too many arguments to function '%E'", expression);
4675                         } else {
4676                                 /* do default promotion */
4677                                 for( ; argument != NULL; argument = argument->next) {
4678                                         type_t *type = argument->expression->base.type;
4679
4680                                         type = skip_typeref(type);
4681                                         if(is_type_integer(type)) {
4682                                                 type = promote_integer(type);
4683                                         } else if(type == type_float) {
4684                                                 type = type_double;
4685                                         }
4686
4687                                         argument->expression
4688                                                 = create_implicit_cast(argument->expression, type);
4689                                 }
4690
4691                                 check_format(&result->call);
4692                         }
4693                 } else {
4694                         check_format(&result->call);
4695                 }
4696         }
4697
4698         return result;
4699 end_error:
4700         return create_invalid_expression();
4701 }
4702
4703 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
4704
4705 static bool same_compound_type(const type_t *type1, const type_t *type2)
4706 {
4707         return
4708                 is_type_compound(type1) &&
4709                 type1->kind == type2->kind &&
4710                 type1->compound.declaration == type2->compound.declaration;
4711 }
4712
4713 /**
4714  * Parse a conditional expression, ie. 'expression ? ... : ...'.
4715  *
4716  * @param expression  the conditional expression
4717  */
4718 static expression_t *parse_conditional_expression(unsigned precedence,
4719                                                   expression_t *expression)
4720 {
4721         eat('?');
4722
4723         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
4724
4725         conditional_expression_t *conditional = &result->conditional;
4726         conditional->condition = expression;
4727
4728         /* 6.5.15.2 */
4729         type_t *const condition_type_orig = expression->base.type;
4730         type_t *const condition_type      = skip_typeref(condition_type_orig);
4731         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
4732                 type_error("expected a scalar type in conditional condition",
4733                            expression->base.source_position, condition_type_orig);
4734         }
4735
4736         expression_t *true_expression = parse_expression();
4737         expect(':');
4738         expression_t *false_expression = parse_sub_expression(precedence);
4739
4740         type_t *const orig_true_type  = true_expression->base.type;
4741         type_t *const orig_false_type = false_expression->base.type;
4742         type_t *const true_type       = skip_typeref(orig_true_type);
4743         type_t *const false_type      = skip_typeref(orig_false_type);
4744
4745         /* 6.5.15.3 */
4746         type_t *result_type;
4747         if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
4748                 result_type = semantic_arithmetic(true_type, false_type);
4749
4750                 true_expression  = create_implicit_cast(true_expression, result_type);
4751                 false_expression = create_implicit_cast(false_expression, result_type);
4752
4753                 conditional->true_expression  = true_expression;
4754                 conditional->false_expression = false_expression;
4755                 conditional->base.type        = result_type;
4756         } else if (same_compound_type(true_type, false_type) || (
4757             is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
4758             is_type_atomic(false_type, ATOMIC_TYPE_VOID)
4759                 )) {
4760                 /* just take 1 of the 2 types */
4761                 result_type = true_type;
4762         } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
4763                         && pointers_compatible(true_type, false_type)) {
4764                 /* ok */
4765                 result_type = true_type;
4766         } else if (is_type_pointer(true_type)
4767                         && is_null_pointer_constant(false_expression)) {
4768                 result_type = true_type;
4769         } else if (is_type_pointer(false_type)
4770                         && is_null_pointer_constant(true_expression)) {
4771                 result_type = false_type;
4772         } else {
4773                 /* TODO: one pointer to void*, other some pointer */
4774
4775                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
4776                         type_error_incompatible("while parsing conditional",
4777                                                 expression->base.source_position, true_type,
4778                                                 false_type);
4779                 }
4780                 result_type = type_error_type;
4781         }
4782
4783         conditional->true_expression
4784                 = create_implicit_cast(true_expression, result_type);
4785         conditional->false_expression
4786                 = create_implicit_cast(false_expression, result_type);
4787         conditional->base.type = result_type;
4788         return result;
4789 end_error:
4790         return create_invalid_expression();
4791 }
4792
4793 /**
4794  * Parse an extension expression.
4795  */
4796 static expression_t *parse_extension(unsigned precedence)
4797 {
4798         eat(T___extension__);
4799
4800         /* TODO enable extensions */
4801         expression_t *expression = parse_sub_expression(precedence);
4802         /* TODO disable extensions */
4803         return expression;
4804 }
4805
4806 /**
4807  * Parse a __builtin_classify_type() expression.
4808  */
4809 static expression_t *parse_builtin_classify_type(const unsigned precedence)
4810 {
4811         eat(T___builtin_classify_type);
4812
4813         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
4814         result->base.type    = type_int;
4815
4816         expect('(');
4817         expression_t *expression = parse_sub_expression(precedence);
4818         expect(')');
4819         result->classify_type.type_expression = expression;
4820
4821         return result;
4822 end_error:
4823         return create_invalid_expression();
4824 }
4825
4826 static void semantic_incdec(unary_expression_t *expression)
4827 {
4828         type_t *const orig_type = expression->value->base.type;
4829         type_t *const type      = skip_typeref(orig_type);
4830         /* TODO !is_type_real && !is_type_pointer */
4831         if(!is_type_arithmetic(type) && type->kind != TYPE_POINTER) {
4832                 if (is_type_valid(type)) {
4833                         /* TODO: improve error message */
4834                         errorf(HERE, "operation needs an arithmetic or pointer type");
4835                 }
4836                 return;
4837         }
4838
4839         expression->base.type = orig_type;
4840 }
4841
4842 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
4843 {
4844         type_t *const orig_type = expression->value->base.type;
4845         type_t *const type      = skip_typeref(orig_type);
4846         if(!is_type_arithmetic(type)) {
4847                 if (is_type_valid(type)) {
4848                         /* TODO: improve error message */
4849                         errorf(HERE, "operation needs an arithmetic type");
4850                 }
4851                 return;
4852         }
4853
4854         expression->base.type = orig_type;
4855 }
4856
4857 static void semantic_unexpr_scalar(unary_expression_t *expression)
4858 {
4859         type_t *const orig_type = expression->value->base.type;
4860         type_t *const type      = skip_typeref(orig_type);
4861         if (!is_type_scalar(type)) {
4862                 if (is_type_valid(type)) {
4863                         errorf(HERE, "operand of ! must be of scalar type");
4864                 }
4865                 return;
4866         }
4867
4868         expression->base.type = orig_type;
4869 }
4870
4871 static void semantic_unexpr_integer(unary_expression_t *expression)
4872 {
4873         type_t *const orig_type = expression->value->base.type;
4874         type_t *const type      = skip_typeref(orig_type);
4875         if (!is_type_integer(type)) {
4876                 if (is_type_valid(type)) {
4877                         errorf(HERE, "operand of ~ must be of integer type");
4878                 }
4879                 return;
4880         }
4881
4882         expression->base.type = orig_type;
4883 }
4884
4885 static void semantic_dereference(unary_expression_t *expression)
4886 {
4887         type_t *const orig_type = expression->value->base.type;
4888         type_t *const type      = skip_typeref(orig_type);
4889         if(!is_type_pointer(type)) {
4890                 if (is_type_valid(type)) {
4891                         errorf(HERE, "Unary '*' needs pointer or arrray type, but type '%T' given", orig_type);
4892                 }
4893                 return;
4894         }
4895
4896         type_t *result_type   = type->pointer.points_to;
4897         result_type           = automatic_type_conversion(result_type);
4898         expression->base.type = result_type;
4899 }
4900
4901 /**
4902  * Check the semantic of the address taken expression.
4903  */
4904 static void semantic_take_addr(unary_expression_t *expression)
4905 {
4906         expression_t *value = expression->value;
4907         value->base.type    = revert_automatic_type_conversion(value);
4908
4909         type_t *orig_type = value->base.type;
4910         if(!is_type_valid(orig_type))
4911                 return;
4912
4913         if(value->kind == EXPR_REFERENCE) {
4914                 declaration_t *const declaration = value->reference.declaration;
4915                 if(declaration != NULL) {
4916                         if (declaration->storage_class == STORAGE_CLASS_REGISTER) {
4917                                 errorf(expression->base.source_position,
4918                                         "address of register variable '%Y' requested",
4919                                         declaration->symbol);
4920                         }
4921                         declaration->address_taken = 1;
4922                 }
4923         }
4924
4925         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
4926 }
4927
4928 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
4929 static expression_t *parse_##unexpression_type(unsigned precedence)            \
4930 {                                                                              \
4931         eat(token_type);                                                           \
4932                                                                                    \
4933         expression_t *unary_expression                                             \
4934                 = allocate_expression_zero(unexpression_type);                         \
4935         unary_expression->base.source_position = HERE;                             \
4936         unary_expression->unary.value = parse_sub_expression(precedence);          \
4937                                                                                    \
4938         sfunc(&unary_expression->unary);                                           \
4939                                                                                    \
4940         return unary_expression;                                                   \
4941 }
4942
4943 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
4944                                semantic_unexpr_arithmetic)
4945 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
4946                                semantic_unexpr_arithmetic)
4947 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
4948                                semantic_unexpr_scalar)
4949 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
4950                                semantic_dereference)
4951 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
4952                                semantic_take_addr)
4953 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
4954                                semantic_unexpr_integer)
4955 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
4956                                semantic_incdec)
4957 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
4958                                semantic_incdec)
4959
4960 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
4961                                                sfunc)                         \
4962 static expression_t *parse_##unexpression_type(unsigned precedence,           \
4963                                                expression_t *left)            \
4964 {                                                                             \
4965         (void) precedence;                                                        \
4966         eat(token_type);                                                          \
4967                                                                               \
4968         expression_t *unary_expression                                            \
4969                 = allocate_expression_zero(unexpression_type);                        \
4970         unary_expression->unary.value = left;                                     \
4971                                                                                   \
4972         sfunc(&unary_expression->unary);                                          \
4973                                                                               \
4974         return unary_expression;                                                  \
4975 }
4976
4977 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
4978                                        EXPR_UNARY_POSTFIX_INCREMENT,
4979                                        semantic_incdec)
4980 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
4981                                        EXPR_UNARY_POSTFIX_DECREMENT,
4982                                        semantic_incdec)
4983
4984 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
4985 {
4986         /* TODO: handle complex + imaginary types */
4987
4988         /* § 6.3.1.8 Usual arithmetic conversions */
4989         if(type_left == type_long_double || type_right == type_long_double) {
4990                 return type_long_double;
4991         } else if(type_left == type_double || type_right == type_double) {
4992                 return type_double;
4993         } else if(type_left == type_float || type_right == type_float) {
4994                 return type_float;
4995         }
4996
4997         type_right = promote_integer(type_right);
4998         type_left  = promote_integer(type_left);
4999
5000         if(type_left == type_right)
5001                 return type_left;
5002
5003         bool signed_left  = is_type_signed(type_left);
5004         bool signed_right = is_type_signed(type_right);
5005         int  rank_left    = get_rank(type_left);
5006         int  rank_right   = get_rank(type_right);
5007         if(rank_left < rank_right) {
5008                 if(signed_left == signed_right || !signed_right) {
5009                         return type_right;
5010                 } else {
5011                         return type_left;
5012                 }
5013         } else {
5014                 if(signed_left == signed_right || !signed_left) {
5015                         return type_left;
5016                 } else {
5017                         return type_right;
5018                 }
5019         }
5020 }
5021
5022 /**
5023  * Check the semantic restrictions for a binary expression.
5024  */
5025 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
5026 {
5027         expression_t *const left            = expression->left;
5028         expression_t *const right           = expression->right;
5029         type_t       *const orig_type_left  = left->base.type;
5030         type_t       *const orig_type_right = right->base.type;
5031         type_t       *const type_left       = skip_typeref(orig_type_left);
5032         type_t       *const type_right      = skip_typeref(orig_type_right);
5033
5034         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
5035                 /* TODO: improve error message */
5036                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
5037                         errorf(HERE, "operation needs arithmetic types");
5038                 }
5039                 return;
5040         }
5041
5042         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
5043         expression->left      = create_implicit_cast(left, arithmetic_type);
5044         expression->right     = create_implicit_cast(right, arithmetic_type);
5045         expression->base.type = arithmetic_type;
5046 }
5047
5048 static void semantic_shift_op(binary_expression_t *expression)
5049 {
5050         expression_t *const left            = expression->left;
5051         expression_t *const right           = expression->right;
5052         type_t       *const orig_type_left  = left->base.type;
5053         type_t       *const orig_type_right = right->base.type;
5054         type_t       *      type_left       = skip_typeref(orig_type_left);
5055         type_t       *      type_right      = skip_typeref(orig_type_right);
5056
5057         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
5058                 /* TODO: improve error message */
5059                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
5060                         errorf(HERE, "operation needs integer types");
5061                 }
5062                 return;
5063         }
5064
5065         type_left  = promote_integer(type_left);
5066         type_right = promote_integer(type_right);
5067
5068         expression->left      = create_implicit_cast(left, type_left);
5069         expression->right     = create_implicit_cast(right, type_right);
5070         expression->base.type = type_left;
5071 }
5072
5073 static void semantic_add(binary_expression_t *expression)
5074 {
5075         expression_t *const left            = expression->left;
5076         expression_t *const right           = expression->right;
5077         type_t       *const orig_type_left  = left->base.type;
5078         type_t       *const orig_type_right = right->base.type;
5079         type_t       *const type_left       = skip_typeref(orig_type_left);
5080         type_t       *const type_right      = skip_typeref(orig_type_right);
5081
5082         /* § 5.6.5 */
5083         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
5084                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
5085                 expression->left  = create_implicit_cast(left, arithmetic_type);
5086                 expression->right = create_implicit_cast(right, arithmetic_type);
5087                 expression->base.type = arithmetic_type;
5088                 return;
5089         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
5090                 expression->base.type = type_left;
5091         } else if(is_type_pointer(type_right) && is_type_integer(type_left)) {
5092                 expression->base.type = type_right;
5093         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
5094                 errorf(HERE, "invalid operands to binary + ('%T', '%T')", orig_type_left, orig_type_right);
5095         }
5096 }
5097
5098 static void semantic_sub(binary_expression_t *expression)
5099 {
5100         expression_t *const left            = expression->left;
5101         expression_t *const right           = expression->right;
5102         type_t       *const orig_type_left  = left->base.type;
5103         type_t       *const orig_type_right = right->base.type;
5104         type_t       *const type_left       = skip_typeref(orig_type_left);
5105         type_t       *const type_right      = skip_typeref(orig_type_right);
5106
5107         /* § 5.6.5 */
5108         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
5109                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
5110                 expression->left        = create_implicit_cast(left, arithmetic_type);
5111                 expression->right       = create_implicit_cast(right, arithmetic_type);
5112                 expression->base.type =  arithmetic_type;
5113                 return;
5114         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
5115                 expression->base.type = type_left;
5116         } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
5117                 if(!pointers_compatible(type_left, type_right)) {
5118                         errorf(HERE,
5119                                "pointers to incompatible objects to binary '-' ('%T', '%T')",
5120                                orig_type_left, orig_type_right);
5121                 } else {
5122                         expression->base.type = type_ptrdiff_t;
5123                 }
5124         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
5125                 errorf(HERE, "invalid operands to binary '-' ('%T', '%T')",
5126                        orig_type_left, orig_type_right);
5127         }
5128 }
5129
5130 /**
5131  * Check the semantics of comparison expressions.
5132  *
5133  * @param expression   The expression to check.
5134  */
5135 static void semantic_comparison(binary_expression_t *expression)
5136 {
5137         expression_t *left            = expression->left;
5138         expression_t *right           = expression->right;
5139         type_t       *orig_type_left  = left->base.type;
5140         type_t       *orig_type_right = right->base.type;
5141
5142         type_t *type_left  = skip_typeref(orig_type_left);
5143         type_t *type_right = skip_typeref(orig_type_right);
5144
5145         /* TODO non-arithmetic types */
5146         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
5147                 if (warning.sign_compare &&
5148                     (expression->base.kind != EXPR_BINARY_EQUAL &&
5149                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
5150                     (is_type_signed(type_left) != is_type_signed(type_right))) {
5151                         warningf(expression->base.source_position,
5152                                  "comparison between signed and unsigned");
5153                 }
5154                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
5155                 expression->left        = create_implicit_cast(left, arithmetic_type);
5156                 expression->right       = create_implicit_cast(right, arithmetic_type);
5157                 expression->base.type   = arithmetic_type;
5158                 if (warning.float_equal &&
5159                     (expression->base.kind == EXPR_BINARY_EQUAL ||
5160                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
5161                     is_type_float(arithmetic_type)) {
5162                         warningf(expression->base.source_position,
5163                                  "comparing floating point with == or != is unsafe");
5164                 }
5165         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
5166                 /* TODO check compatibility */
5167         } else if (is_type_pointer(type_left)) {
5168                 expression->right = create_implicit_cast(right, type_left);
5169         } else if (is_type_pointer(type_right)) {
5170                 expression->left = create_implicit_cast(left, type_right);
5171         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
5172                 type_error_incompatible("invalid operands in comparison",
5173                                         expression->base.source_position,
5174                                         type_left, type_right);
5175         }
5176         expression->base.type = type_int;
5177 }
5178
5179 static void semantic_arithmetic_assign(binary_expression_t *expression)
5180 {
5181         expression_t *left            = expression->left;
5182         expression_t *right           = expression->right;
5183         type_t       *orig_type_left  = left->base.type;
5184         type_t       *orig_type_right = right->base.type;
5185
5186         type_t *type_left  = skip_typeref(orig_type_left);
5187         type_t *type_right = skip_typeref(orig_type_right);
5188
5189         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
5190                 /* TODO: improve error message */
5191                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
5192                         errorf(HERE, "operation needs arithmetic types");
5193                 }
5194                 return;
5195         }
5196
5197         /* combined instructions are tricky. We can't create an implicit cast on
5198          * the left side, because we need the uncasted form for the store.
5199          * The ast2firm pass has to know that left_type must be right_type
5200          * for the arithmetic operation and create a cast by itself */
5201         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
5202         expression->right       = create_implicit_cast(right, arithmetic_type);
5203         expression->base.type   = type_left;
5204 }
5205
5206 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
5207 {
5208         expression_t *const left            = expression->left;
5209         expression_t *const right           = expression->right;
5210         type_t       *const orig_type_left  = left->base.type;
5211         type_t       *const orig_type_right = right->base.type;
5212         type_t       *const type_left       = skip_typeref(orig_type_left);
5213         type_t       *const type_right      = skip_typeref(orig_type_right);
5214
5215         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
5216                 /* combined instructions are tricky. We can't create an implicit cast on
5217                  * the left side, because we need the uncasted form for the store.
5218                  * The ast2firm pass has to know that left_type must be right_type
5219                  * for the arithmetic operation and create a cast by itself */
5220                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
5221                 expression->right     = create_implicit_cast(right, arithmetic_type);
5222                 expression->base.type = type_left;
5223         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
5224                 expression->base.type = type_left;
5225         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
5226                 errorf(HERE, "incompatible types '%T' and '%T' in assignment", orig_type_left, orig_type_right);
5227         }
5228 }
5229
5230 /**
5231  * Check the semantic restrictions of a logical expression.
5232  */
5233 static void semantic_logical_op(binary_expression_t *expression)
5234 {
5235         expression_t *const left            = expression->left;
5236         expression_t *const right           = expression->right;
5237         type_t       *const orig_type_left  = left->base.type;
5238         type_t       *const orig_type_right = right->base.type;
5239         type_t       *const type_left       = skip_typeref(orig_type_left);
5240         type_t       *const type_right      = skip_typeref(orig_type_right);
5241
5242         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
5243                 /* TODO: improve error message */
5244                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
5245                         errorf(HERE, "operation needs scalar types");
5246                 }
5247                 return;
5248         }
5249
5250         expression->base.type = type_int;
5251 }
5252
5253 /**
5254  * Checks if a compound type has constant fields.
5255  */
5256 static bool has_const_fields(const compound_type_t *type)
5257 {
5258         const scope_t       *scope       = &type->declaration->scope;
5259         const declaration_t *declaration = scope->declarations;
5260
5261         for (; declaration != NULL; declaration = declaration->next) {
5262                 if (declaration->namespc != NAMESPACE_NORMAL)
5263                         continue;
5264
5265                 const type_t *decl_type = skip_typeref(declaration->type);
5266                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
5267                         return true;
5268         }
5269         /* TODO */
5270         return false;
5271 }
5272
5273 /**
5274  * Check the semantic restrictions of a binary assign expression.
5275  */
5276 static void semantic_binexpr_assign(binary_expression_t *expression)
5277 {
5278         expression_t *left           = expression->left;
5279         type_t       *orig_type_left = left->base.type;
5280
5281         type_t *type_left = revert_automatic_type_conversion(left);
5282         type_left         = skip_typeref(orig_type_left);
5283
5284         /* must be a modifiable lvalue */
5285         if (is_type_array(type_left)) {
5286                 errorf(HERE, "cannot assign to arrays ('%E')", left);
5287                 return;
5288         }
5289         if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
5290                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
5291                        orig_type_left);
5292                 return;
5293         }
5294         if(is_type_incomplete(type_left)) {
5295                 errorf(HERE,
5296                        "left-hand side of assignment '%E' has incomplete type '%T'",
5297                        left, orig_type_left);
5298                 return;
5299         }
5300         if(is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
5301                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
5302                        left, orig_type_left);
5303                 return;
5304         }
5305
5306         type_t *const res_type = semantic_assign(orig_type_left, expression->right,
5307                                                  "assignment");
5308         if (res_type == NULL) {
5309                 errorf(expression->base.source_position,
5310                         "cannot assign to '%T' from '%T'",
5311                         orig_type_left, expression->right->base.type);
5312         } else {
5313                 expression->right = create_implicit_cast(expression->right, res_type);
5314         }
5315
5316         expression->base.type = orig_type_left;
5317 }
5318
5319 /**
5320  * Determine if the outermost operation (or parts thereof) of the given
5321  * expression has no effect in order to generate a warning about this fact.
5322  * Therefore in some cases this only examines some of the operands of the
5323  * expression (see comments in the function and examples below).
5324  * Examples:
5325  *   f() + 23;    // warning, because + has no effect
5326  *   x || f();    // no warning, because x controls execution of f()
5327  *   x ? y : f(); // warning, because y has no effect
5328  *   (void)x;     // no warning to be able to suppress the warning
5329  * This function can NOT be used for an "expression has definitely no effect"-
5330  * analysis. */
5331 static bool expression_has_effect(const expression_t *const expr)
5332 {
5333         switch (expr->kind) {
5334                 case EXPR_UNKNOWN:                   break;
5335                 case EXPR_INVALID:                   return true; /* do NOT warn */
5336                 case EXPR_REFERENCE:                 return false;
5337                 case EXPR_CONST:                     return false;
5338                 case EXPR_CHARACTER_CONSTANT:        return false;
5339                 case EXPR_WIDE_CHARACTER_CONSTANT:   return false;
5340                 case EXPR_STRING_LITERAL:            return false;
5341                 case EXPR_WIDE_STRING_LITERAL:       return false;
5342
5343                 case EXPR_CALL: {
5344                         const call_expression_t *const call = &expr->call;
5345                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
5346                                 return true;
5347
5348                         switch (call->function->builtin_symbol.symbol->ID) {
5349                                 case T___builtin_va_end: return true;
5350                                 default:                 return false;
5351                         }
5352                 }
5353
5354                 /* Generate the warning if either the left or right hand side of a
5355                  * conditional expression has no effect */
5356                 case EXPR_CONDITIONAL: {
5357                         const conditional_expression_t *const cond = &expr->conditional;
5358                         return
5359                                 expression_has_effect(cond->true_expression) &&
5360                                 expression_has_effect(cond->false_expression);
5361                 }
5362
5363                 case EXPR_SELECT:                    return false;
5364                 case EXPR_ARRAY_ACCESS:              return false;
5365                 case EXPR_SIZEOF:                    return false;
5366                 case EXPR_CLASSIFY_TYPE:             return false;
5367                 case EXPR_ALIGNOF:                   return false;
5368
5369                 case EXPR_FUNCTION:                  return false;
5370                 case EXPR_PRETTY_FUNCTION:           return false;
5371                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
5372                 case EXPR_BUILTIN_CONSTANT_P:        return false;
5373                 case EXPR_BUILTIN_PREFETCH:          return true;
5374                 case EXPR_OFFSETOF:                  return false;
5375                 case EXPR_VA_START:                  return true;
5376                 case EXPR_VA_ARG:                    return true;
5377                 case EXPR_STATEMENT:                 return true; // TODO
5378                 case EXPR_COMPOUND_LITERAL:          return false;
5379
5380                 case EXPR_UNARY_NEGATE:              return false;
5381                 case EXPR_UNARY_PLUS:                return false;
5382                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
5383                 case EXPR_UNARY_NOT:                 return false;
5384                 case EXPR_UNARY_DEREFERENCE:         return false;
5385                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
5386                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
5387                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
5388                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
5389                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
5390
5391                 /* Treat void casts as if they have an effect in order to being able to
5392                  * suppress the warning */
5393                 case EXPR_UNARY_CAST: {
5394                         type_t *const type = skip_typeref(expr->base.type);
5395                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
5396                 }
5397
5398                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
5399                 case EXPR_UNARY_ASSUME:              return true;
5400                 case EXPR_UNARY_BITFIELD_EXTRACT:    return false;
5401
5402                 case EXPR_BINARY_ADD:                return false;
5403                 case EXPR_BINARY_SUB:                return false;
5404                 case EXPR_BINARY_MUL:                return false;
5405                 case EXPR_BINARY_DIV:                return false;
5406                 case EXPR_BINARY_MOD:                return false;
5407                 case EXPR_BINARY_EQUAL:              return false;
5408                 case EXPR_BINARY_NOTEQUAL:           return false;
5409                 case EXPR_BINARY_LESS:               return false;
5410                 case EXPR_BINARY_LESSEQUAL:          return false;
5411                 case EXPR_BINARY_GREATER:            return false;
5412                 case EXPR_BINARY_GREATEREQUAL:       return false;
5413                 case EXPR_BINARY_BITWISE_AND:        return false;
5414                 case EXPR_BINARY_BITWISE_OR:         return false;
5415                 case EXPR_BINARY_BITWISE_XOR:        return false;
5416                 case EXPR_BINARY_SHIFTLEFT:          return false;
5417                 case EXPR_BINARY_SHIFTRIGHT:         return false;
5418                 case EXPR_BINARY_ASSIGN:             return true;
5419                 case EXPR_BINARY_MUL_ASSIGN:         return true;
5420                 case EXPR_BINARY_DIV_ASSIGN:         return true;
5421                 case EXPR_BINARY_MOD_ASSIGN:         return true;
5422                 case EXPR_BINARY_ADD_ASSIGN:         return true;
5423                 case EXPR_BINARY_SUB_ASSIGN:         return true;
5424                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
5425                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
5426                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
5427                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
5428                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
5429
5430                 /* Only examine the right hand side of && and ||, because the left hand
5431                  * side already has the effect of controlling the execution of the right
5432                  * hand side */
5433                 case EXPR_BINARY_LOGICAL_AND:
5434                 case EXPR_BINARY_LOGICAL_OR:
5435                 /* Only examine the right hand side of a comma expression, because the left
5436                  * hand side has a separate warning */
5437                 case EXPR_BINARY_COMMA:
5438                         return expression_has_effect(expr->binary.right);
5439
5440                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
5441                 case EXPR_BINARY_ISGREATER:          return false;
5442                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
5443                 case EXPR_BINARY_ISLESS:             return false;
5444                 case EXPR_BINARY_ISLESSEQUAL:        return false;
5445                 case EXPR_BINARY_ISLESSGREATER:      return false;
5446                 case EXPR_BINARY_ISUNORDERED:        return false;
5447         }
5448
5449         panic("unexpected expression");
5450 }
5451
5452 static void semantic_comma(binary_expression_t *expression)
5453 {
5454         if (warning.unused_value) {
5455                 const expression_t *const left = expression->left;
5456                 if (!expression_has_effect(left)) {
5457                         warningf(left->base.source_position, "left-hand operand of comma expression has no effect");
5458                 }
5459         }
5460         expression->base.type = expression->right->base.type;
5461 }
5462
5463 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
5464 static expression_t *parse_##binexpression_type(unsigned precedence,      \
5465                                                 expression_t *left)       \
5466 {                                                                         \
5467         eat(token_type);                                                      \
5468         source_position_t pos = HERE;                                         \
5469                                                                           \
5470         expression_t *right = parse_sub_expression(precedence + lr);          \
5471                                                                           \
5472         expression_t *binexpr = allocate_expression_zero(binexpression_type); \
5473         binexpr->base.source_position = pos;                                  \
5474         binexpr->binary.left  = left;                                         \
5475         binexpr->binary.right = right;                                        \
5476         sfunc(&binexpr->binary);                                              \
5477                                                                           \
5478         return binexpr;                                                       \
5479 }
5480
5481 CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
5482 CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
5483 CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
5484 CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
5485 CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
5486 CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
5487 CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
5488 CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
5489 CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
5490
5491 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
5492                       semantic_comparison, 1)
5493 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
5494                       semantic_comparison, 1)
5495 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
5496                       semantic_comparison, 1)
5497 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
5498                       semantic_comparison, 1)
5499
5500 CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
5501                       semantic_binexpr_arithmetic, 1)
5502 CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
5503                       semantic_binexpr_arithmetic, 1)
5504 CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
5505                       semantic_binexpr_arithmetic, 1)
5506 CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
5507                       semantic_logical_op, 1)
5508 CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
5509                       semantic_logical_op, 1)
5510 CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
5511                       semantic_shift_op, 1)
5512 CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
5513                       semantic_shift_op, 1)
5514 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
5515                       semantic_arithmetic_addsubb_assign, 0)
5516 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
5517                       semantic_arithmetic_addsubb_assign, 0)
5518 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
5519                       semantic_arithmetic_assign, 0)
5520 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
5521                       semantic_arithmetic_assign, 0)
5522 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
5523                       semantic_arithmetic_assign, 0)
5524 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
5525                       semantic_arithmetic_assign, 0)
5526 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
5527                       semantic_arithmetic_assign, 0)
5528 CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
5529                       semantic_arithmetic_assign, 0)
5530 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
5531                       semantic_arithmetic_assign, 0)
5532 CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
5533                       semantic_arithmetic_assign, 0)
5534
5535 static expression_t *parse_sub_expression(unsigned precedence)
5536 {
5537         if(token.type < 0) {
5538                 return expected_expression_error();
5539         }
5540
5541         expression_parser_function_t *parser
5542                 = &expression_parsers[token.type];
5543         source_position_t             source_position = token.source_position;
5544         expression_t                 *left;
5545
5546         if(parser->parser != NULL) {
5547                 left = parser->parser(parser->precedence);
5548         } else {
5549                 left = parse_primary_expression();
5550         }
5551         assert(left != NULL);
5552         left->base.source_position = source_position;
5553
5554         while(true) {
5555                 if(token.type < 0) {
5556                         return expected_expression_error();
5557                 }
5558
5559                 parser = &expression_parsers[token.type];
5560                 if(parser->infix_parser == NULL)
5561                         break;
5562                 if(parser->infix_precedence < precedence)
5563                         break;
5564
5565                 left = parser->infix_parser(parser->infix_precedence, left);
5566
5567                 assert(left != NULL);
5568                 assert(left->kind != EXPR_UNKNOWN);
5569                 left->base.source_position = source_position;
5570         }
5571
5572         return left;
5573 }
5574
5575 /**
5576  * Parse an expression.
5577  */
5578 static expression_t *parse_expression(void)
5579 {
5580         return parse_sub_expression(1);
5581 }
5582
5583 /**
5584  * Register a parser for a prefix-like operator with given precedence.
5585  *
5586  * @param parser      the parser function
5587  * @param token_type  the token type of the prefix token
5588  * @param precedence  the precedence of the operator
5589  */
5590 static void register_expression_parser(parse_expression_function parser,
5591                                        int token_type, unsigned precedence)
5592 {
5593         expression_parser_function_t *entry = &expression_parsers[token_type];
5594
5595         if(entry->parser != NULL) {
5596                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
5597                 panic("trying to register multiple expression parsers for a token");
5598         }
5599         entry->parser     = parser;
5600         entry->precedence = precedence;
5601 }
5602
5603 /**
5604  * Register a parser for an infix operator with given precedence.
5605  *
5606  * @param parser      the parser function
5607  * @param token_type  the token type of the infix operator
5608  * @param precedence  the precedence of the operator
5609  */
5610 static void register_infix_parser(parse_expression_infix_function parser,
5611                 int token_type, unsigned precedence)
5612 {
5613         expression_parser_function_t *entry = &expression_parsers[token_type];
5614
5615         if(entry->infix_parser != NULL) {
5616                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
5617                 panic("trying to register multiple infix expression parsers for a "
5618                       "token");
5619         }
5620         entry->infix_parser     = parser;
5621         entry->infix_precedence = precedence;
5622 }
5623
5624 /**
5625  * Initialize the expression parsers.
5626  */
5627 static void init_expression_parsers(void)
5628 {
5629         memset(&expression_parsers, 0, sizeof(expression_parsers));
5630
5631         register_infix_parser(parse_array_expression,         '[',              30);
5632         register_infix_parser(parse_call_expression,          '(',              30);
5633         register_infix_parser(parse_select_expression,        '.',              30);
5634         register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
5635         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
5636                                                               T_PLUSPLUS,       30);
5637         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
5638                                                               T_MINUSMINUS,     30);
5639
5640         register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
5641         register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
5642         register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
5643         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
5644         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
5645         register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
5646         register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
5647         register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
5648         register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
5649         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
5650         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
5651         register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
5652         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
5653                                                     T_EXCLAMATIONMARKEQUAL, 13);
5654         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
5655         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
5656         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
5657         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
5658         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
5659         register_infix_parser(parse_conditional_expression,   '?',               7);
5660         register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
5661         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
5662         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
5663         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
5664         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
5665         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
5666         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
5667                                                                 T_LESSLESSEQUAL, 2);
5668         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
5669                                                           T_GREATERGREATEREQUAL, 2);
5670         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
5671                                                                      T_ANDEQUAL, 2);
5672         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
5673                                                                     T_PIPEEQUAL, 2);
5674         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
5675                                                                    T_CARETEQUAL, 2);
5676
5677         register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
5678
5679         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
5680         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
5681         register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
5682         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
5683         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
5684         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
5685         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
5686                                                                   T_PLUSPLUS,   25);
5687         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
5688                                                                   T_MINUSMINUS, 25);
5689         register_expression_parser(parse_sizeof,                      T_sizeof, 25);
5690         register_expression_parser(parse_alignof,                T___alignof__, 25);
5691         register_expression_parser(parse_extension,            T___extension__, 25);
5692         register_expression_parser(parse_builtin_classify_type,
5693                                                      T___builtin_classify_type, 25);
5694 }
5695
5696 /**
5697  * Parse a asm statement constraints specification.
5698  */
5699 static asm_constraint_t *parse_asm_constraints(void)
5700 {
5701         asm_constraint_t *result = NULL;
5702         asm_constraint_t *last   = NULL;
5703
5704         while(token.type == T_STRING_LITERAL || token.type == '[') {
5705                 asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
5706                 memset(constraint, 0, sizeof(constraint[0]));
5707
5708                 if(token.type == '[') {
5709                         eat('[');
5710                         if(token.type != T_IDENTIFIER) {
5711                                 parse_error_expected("while parsing asm constraint",
5712                                                      T_IDENTIFIER, 0);
5713                                 return NULL;
5714                         }
5715                         constraint->symbol = token.v.symbol;
5716
5717                         expect(']');
5718                 }
5719
5720                 constraint->constraints = parse_string_literals();
5721                 expect('(');
5722                 constraint->expression = parse_expression();
5723                 expect(')');
5724
5725                 if(last != NULL) {
5726                         last->next = constraint;
5727                 } else {
5728                         result = constraint;
5729                 }
5730                 last = constraint;
5731
5732                 if(token.type != ',')
5733                         break;
5734                 eat(',');
5735         }
5736
5737         return result;
5738 end_error:
5739         return NULL;
5740 }
5741
5742 /**
5743  * Parse a asm statement clobber specification.
5744  */
5745 static asm_clobber_t *parse_asm_clobbers(void)
5746 {
5747         asm_clobber_t *result = NULL;
5748         asm_clobber_t *last   = NULL;
5749
5750         while(token.type == T_STRING_LITERAL) {
5751                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
5752                 clobber->clobber       = parse_string_literals();
5753
5754                 if(last != NULL) {
5755                         last->next = clobber;
5756                 } else {
5757                         result = clobber;
5758                 }
5759                 last = clobber;
5760
5761                 if(token.type != ',')
5762                         break;
5763                 eat(',');
5764         }
5765
5766         return result;
5767 }
5768
5769 /**
5770  * Parse an asm statement.
5771  */
5772 static statement_t *parse_asm_statement(void)
5773 {
5774         eat(T_asm);
5775
5776         statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
5777         statement->base.source_position = token.source_position;
5778
5779         asm_statement_t *asm_statement = &statement->asms;
5780
5781         if(token.type == T_volatile) {
5782                 next_token();
5783                 asm_statement->is_volatile = true;
5784         }
5785
5786         expect('(');
5787         asm_statement->asm_text = parse_string_literals();
5788
5789         if(token.type != ':')
5790                 goto end_of_asm;
5791         eat(':');
5792
5793         asm_statement->inputs = parse_asm_constraints();
5794         if(token.type != ':')
5795                 goto end_of_asm;
5796         eat(':');
5797
5798         asm_statement->outputs = parse_asm_constraints();
5799         if(token.type != ':')
5800                 goto end_of_asm;
5801         eat(':');
5802
5803         asm_statement->clobbers = parse_asm_clobbers();
5804
5805 end_of_asm:
5806         expect(')');
5807         expect(';');
5808         return statement;
5809 end_error:
5810         return NULL;
5811 }
5812
5813 /**
5814  * Parse a case statement.
5815  */
5816 static statement_t *parse_case_statement(void)
5817 {
5818         eat(T_case);
5819
5820         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
5821
5822         statement->base.source_position  = token.source_position;
5823         statement->case_label.expression = parse_expression();
5824
5825         if (c_mode & _GNUC) {
5826                 if (token.type == T_DOTDOTDOT) {
5827                         next_token();
5828                         statement->case_label.end_range = parse_expression();
5829                 }
5830         }
5831
5832         expect(':');
5833
5834         if (! is_constant_expression(statement->case_label.expression)) {
5835                 errorf(statement->base.source_position,
5836                         "case label does not reduce to an integer constant");
5837         } else {
5838                 /* TODO: check if the case label is already known */
5839                 if (current_switch != NULL) {
5840                         /* link all cases into the switch statement */
5841                         if (current_switch->last_case == NULL) {
5842                                 current_switch->first_case =
5843                                 current_switch->last_case  = &statement->case_label;
5844                         } else {
5845                                 current_switch->last_case->next = &statement->case_label;
5846                         }
5847                 } else {
5848                         errorf(statement->base.source_position,
5849                                 "case label not within a switch statement");
5850                 }
5851         }
5852         statement->case_label.statement = parse_statement();
5853
5854         return statement;
5855 end_error:
5856         return NULL;
5857 }
5858
5859 /**
5860  * Finds an existing default label of a switch statement.
5861  */
5862 static case_label_statement_t *
5863 find_default_label(const switch_statement_t *statement)
5864 {
5865         case_label_statement_t *label = statement->first_case;
5866         for ( ; label != NULL; label = label->next) {
5867                 if (label->expression == NULL)
5868                         return label;
5869         }
5870         return NULL;
5871 }
5872
5873 /**
5874  * Parse a default statement.
5875  */
5876 static statement_t *parse_default_statement(void)
5877 {
5878         eat(T_default);
5879
5880         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
5881
5882         statement->base.source_position = token.source_position;
5883
5884         expect(':');
5885         if (current_switch != NULL) {
5886                 const case_label_statement_t *def_label = find_default_label(current_switch);
5887                 if (def_label != NULL) {
5888                         errorf(HERE, "multiple default labels in one switch");
5889                         errorf(def_label->base.source_position,
5890                                 "this is the first default label");
5891                 } else {
5892                         /* link all cases into the switch statement */
5893                         if (current_switch->last_case == NULL) {
5894                                 current_switch->first_case =
5895                                         current_switch->last_case  = &statement->case_label;
5896                         } else {
5897                                 current_switch->last_case->next = &statement->case_label;
5898                         }
5899                 }
5900         } else {
5901                 errorf(statement->base.source_position,
5902                         "'default' label not within a switch statement");
5903         }
5904         statement->case_label.statement = parse_statement();
5905
5906         return statement;
5907 end_error:
5908         return NULL;
5909 }
5910
5911 /**
5912  * Return the declaration for a given label symbol or create a new one.
5913  */
5914 static declaration_t *get_label(symbol_t *symbol)
5915 {
5916         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
5917         assert(current_function != NULL);
5918         /* if we found a label in the same function, then we already created the
5919          * declaration */
5920         if(candidate != NULL
5921                         && candidate->parent_scope == &current_function->scope) {
5922                 return candidate;
5923         }
5924
5925         /* otherwise we need to create a new one */
5926         declaration_t *const declaration = allocate_declaration_zero();
5927         declaration->namespc       = NAMESPACE_LABEL;
5928         declaration->symbol        = symbol;
5929
5930         label_push(declaration);
5931
5932         return declaration;
5933 }
5934
5935 /**
5936  * Parse a label statement.
5937  */
5938 static statement_t *parse_label_statement(void)
5939 {
5940         assert(token.type == T_IDENTIFIER);
5941         symbol_t *symbol = token.v.symbol;
5942         next_token();
5943
5944         declaration_t *label = get_label(symbol);
5945
5946         /* if source position is already set then the label is defined twice,
5947          * otherwise it was just mentioned in a goto so far */
5948         if(label->source_position.input_name != NULL) {
5949                 errorf(HERE, "duplicate label '%Y'", symbol);
5950                 errorf(label->source_position, "previous definition of '%Y' was here",
5951                        symbol);
5952         } else {
5953                 label->source_position = token.source_position;
5954         }
5955
5956         statement_t *statement = allocate_statement_zero(STATEMENT_LABEL);
5957
5958         statement->base.source_position = token.source_position;
5959         statement->label.label          = label;
5960
5961         eat(':');
5962
5963         if(token.type == '}') {
5964                 /* TODO only warn? */
5965                 errorf(HERE, "label at end of compound statement");
5966                 return statement;
5967         } else {
5968                 if (token.type == ';') {
5969                         /* eat an empty statement here, to avoid the warning about an empty
5970                          * after a label.  label:; is commonly used to have a label before
5971                          * a }. */
5972                         next_token();
5973                 } else {
5974                         statement->label.statement = parse_statement();
5975                 }
5976         }
5977
5978         /* remember the labels's in a list for later checking */
5979         if (label_last == NULL) {
5980                 label_first = &statement->label;
5981         } else {
5982                 label_last->next = &statement->label;
5983         }
5984         label_last = &statement->label;
5985
5986         return statement;
5987 }
5988
5989 /**
5990  * Parse an if statement.
5991  */
5992 static statement_t *parse_if(void)
5993 {
5994         eat(T_if);
5995
5996         statement_t *statement          = allocate_statement_zero(STATEMENT_IF);
5997         statement->base.source_position = token.source_position;
5998
5999         expect('(');
6000         statement->ifs.condition = parse_expression();
6001         expect(')');
6002
6003         statement->ifs.true_statement = parse_statement();
6004         if(token.type == T_else) {
6005                 next_token();
6006                 statement->ifs.false_statement = parse_statement();
6007         }
6008
6009         return statement;
6010 end_error:
6011         return NULL;
6012 }
6013
6014 /**
6015  * Parse a switch statement.
6016  */
6017 static statement_t *parse_switch(void)
6018 {
6019         eat(T_switch);
6020
6021         statement_t *statement          = allocate_statement_zero(STATEMENT_SWITCH);
6022         statement->base.source_position = token.source_position;
6023
6024         expect('(');
6025         expression_t *const expr = parse_expression();
6026         type_t       *      type = skip_typeref(expr->base.type);
6027         if (is_type_integer(type)) {
6028                 type = promote_integer(type);
6029         } else if (is_type_valid(type)) {
6030                 errorf(expr->base.source_position,
6031                        "switch quantity is not an integer, but '%T'", type);
6032                 type = type_error_type;
6033         }
6034         statement->switchs.expression = create_implicit_cast(expr, type);
6035         expect(')');
6036
6037         switch_statement_t *rem = current_switch;
6038         current_switch          = &statement->switchs;
6039         statement->switchs.body = parse_statement();
6040         current_switch          = rem;
6041
6042         if (warning.switch_default
6043                         && find_default_label(&statement->switchs) == NULL) {
6044                 warningf(statement->base.source_position, "switch has no default case");
6045         }
6046
6047         return statement;
6048 end_error:
6049         return NULL;
6050 }
6051
6052 static statement_t *parse_loop_body(statement_t *const loop)
6053 {
6054         statement_t *const rem = current_loop;
6055         current_loop = loop;
6056
6057         statement_t *const body = parse_statement();
6058
6059         current_loop = rem;
6060         return body;
6061 }
6062
6063 /**
6064  * Parse a while statement.
6065  */
6066 static statement_t *parse_while(void)
6067 {
6068         eat(T_while);
6069
6070         statement_t *statement          = allocate_statement_zero(STATEMENT_WHILE);
6071         statement->base.source_position = token.source_position;
6072
6073         expect('(');
6074         statement->whiles.condition = parse_expression();
6075         expect(')');
6076
6077         statement->whiles.body = parse_loop_body(statement);
6078
6079         return statement;
6080 end_error:
6081         return NULL;
6082 }
6083
6084 /**
6085  * Parse a do statement.
6086  */
6087 static statement_t *parse_do(void)
6088 {
6089         eat(T_do);
6090
6091         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
6092
6093         statement->base.source_position = token.source_position;
6094
6095         statement->do_while.body = parse_loop_body(statement);
6096
6097         expect(T_while);
6098         expect('(');
6099         statement->do_while.condition = parse_expression();
6100         expect(')');
6101         expect(';');
6102
6103         return statement;
6104 end_error:
6105         return NULL;
6106 }
6107
6108 /**
6109  * Parse a for statement.
6110  */
6111 static statement_t *parse_for(void)
6112 {
6113         eat(T_for);
6114
6115         statement_t *statement          = allocate_statement_zero(STATEMENT_FOR);
6116         statement->base.source_position = token.source_position;
6117
6118         int      top        = environment_top();
6119         scope_t *last_scope = scope;
6120         set_scope(&statement->fors.scope);
6121
6122         expect('(');
6123
6124         if(token.type != ';') {
6125                 if(is_declaration_specifier(&token, false)) {
6126                         parse_declaration(record_declaration);
6127                 } else {
6128                         expression_t *const init = parse_expression();
6129                         statement->fors.initialisation = init;
6130                         if (warning.unused_value  && !expression_has_effect(init)) {
6131                                 warningf(init->base.source_position,
6132                                          "initialisation of 'for'-statement has no effect");
6133                         }
6134                         expect(';');
6135                 }
6136         } else {
6137                 expect(';');
6138         }
6139
6140         if(token.type != ';') {
6141                 statement->fors.condition = parse_expression();
6142         }
6143         expect(';');
6144         if(token.type != ')') {
6145                 expression_t *const step = parse_expression();
6146                 statement->fors.step = step;
6147                 if (warning.unused_value  && !expression_has_effect(step)) {
6148                         warningf(step->base.source_position,
6149                                  "step of 'for'-statement has no effect");
6150                 }
6151         }
6152         expect(')');
6153         statement->fors.body = parse_loop_body(statement);
6154
6155         assert(scope == &statement->fors.scope);
6156         set_scope(last_scope);
6157         environment_pop_to(top);
6158
6159         return statement;
6160
6161 end_error:
6162         assert(scope == &statement->fors.scope);
6163         set_scope(last_scope);
6164         environment_pop_to(top);
6165
6166         return NULL;
6167 }
6168
6169 /**
6170  * Parse a goto statement.
6171  */
6172 static statement_t *parse_goto(void)
6173 {
6174         eat(T_goto);
6175
6176         if(token.type != T_IDENTIFIER) {
6177                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
6178                 eat_statement();
6179                 return NULL;
6180         }
6181         symbol_t *symbol = token.v.symbol;
6182         next_token();
6183
6184         declaration_t *label = get_label(symbol);
6185
6186         statement_t *statement          = allocate_statement_zero(STATEMENT_GOTO);
6187         statement->base.source_position = token.source_position;
6188
6189         statement->gotos.label = label;
6190
6191         /* remember the goto's in a list for later checking */
6192         if (goto_last == NULL) {
6193                 goto_first = &statement->gotos;
6194         } else {
6195                 goto_last->next = &statement->gotos;
6196         }
6197         goto_last = &statement->gotos;
6198
6199         expect(';');
6200
6201         return statement;
6202 end_error:
6203         return NULL;
6204 }
6205
6206 /**
6207  * Parse a continue statement.
6208  */
6209 static statement_t *parse_continue(void)
6210 {
6211         statement_t *statement;
6212         if (current_loop == NULL) {
6213                 errorf(HERE, "continue statement not within loop");
6214                 statement = NULL;
6215         } else {
6216                 statement = allocate_statement_zero(STATEMENT_CONTINUE);
6217
6218                 statement->base.source_position = token.source_position;
6219         }
6220
6221         eat(T_continue);
6222         expect(';');
6223
6224         return statement;
6225 end_error:
6226         return NULL;
6227 }
6228
6229 /**
6230  * Parse a break statement.
6231  */
6232 static statement_t *parse_break(void)
6233 {
6234         statement_t *statement;
6235         if (current_switch == NULL && current_loop == NULL) {
6236                 errorf(HERE, "break statement not within loop or switch");
6237                 statement = NULL;
6238         } else {
6239                 statement = allocate_statement_zero(STATEMENT_BREAK);
6240
6241                 statement->base.source_position = token.source_position;
6242         }
6243
6244         eat(T_break);
6245         expect(';');
6246
6247         return statement;
6248 end_error:
6249         return NULL;
6250 }
6251
6252 /**
6253  * Check if a given declaration represents a local variable.
6254  */
6255 static bool is_local_var_declaration(const declaration_t *declaration) {
6256         switch ((storage_class_tag_t) declaration->storage_class) {
6257         case STORAGE_CLASS_AUTO:
6258         case STORAGE_CLASS_REGISTER: {
6259                 const type_t *type = skip_typeref(declaration->type);
6260                 if(is_type_function(type)) {
6261                         return false;
6262                 } else {
6263                         return true;
6264                 }
6265         }
6266         default:
6267                 return false;
6268         }
6269 }
6270
6271 /**
6272  * Check if a given declaration represents a variable.
6273  */
6274 static bool is_var_declaration(const declaration_t *declaration) {
6275         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF)
6276                 return false;
6277
6278         const type_t *type = skip_typeref(declaration->type);
6279         return !is_type_function(type);
6280 }
6281
6282 /**
6283  * Check if a given expression represents a local variable.
6284  */
6285 static bool is_local_variable(const expression_t *expression)
6286 {
6287         if (expression->base.kind != EXPR_REFERENCE) {
6288                 return false;
6289         }
6290         const declaration_t *declaration = expression->reference.declaration;
6291         return is_local_var_declaration(declaration);
6292 }
6293
6294 /**
6295  * Check if a given expression represents a local variable and
6296  * return its declaration then, else return NULL.
6297  */
6298 declaration_t *expr_is_variable(const expression_t *expression)
6299 {
6300         if (expression->base.kind != EXPR_REFERENCE) {
6301                 return NULL;
6302         }
6303         declaration_t *declaration = expression->reference.declaration;
6304         if (is_var_declaration(declaration))
6305                 return declaration;
6306         return NULL;
6307 }
6308
6309 /**
6310  * Parse a return statement.
6311  */
6312 static statement_t *parse_return(void)
6313 {
6314         eat(T_return);
6315
6316         statement_t *statement          = allocate_statement_zero(STATEMENT_RETURN);
6317         statement->base.source_position = token.source_position;
6318
6319         expression_t *return_value = NULL;
6320         if(token.type != ';') {
6321                 return_value = parse_expression();
6322         }
6323         expect(';');
6324
6325         const type_t *const func_type = current_function->type;
6326         assert(is_type_function(func_type));
6327         type_t *const return_type = skip_typeref(func_type->function.return_type);
6328
6329         if(return_value != NULL) {
6330                 type_t *return_value_type = skip_typeref(return_value->base.type);
6331
6332                 if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
6333                                 && !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
6334                         warningf(statement->base.source_position,
6335                                  "'return' with a value, in function returning void");
6336                         return_value = NULL;
6337                 } else {
6338                         type_t *const res_type = semantic_assign(return_type,
6339                                 return_value, "'return'");
6340                         if (res_type == NULL) {
6341                                 errorf(statement->base.source_position,
6342                                        "cannot return something of type '%T' in function returning '%T'",
6343                                        return_value->base.type, return_type);
6344                         } else {
6345                                 return_value = create_implicit_cast(return_value, res_type);
6346                         }
6347                 }
6348                 /* check for returning address of a local var */
6349                 if (return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
6350                         const expression_t *expression = return_value->unary.value;
6351                         if (is_local_variable(expression)) {
6352                                 warningf(statement->base.source_position,
6353                                          "function returns address of local variable");
6354                         }
6355                 }
6356         } else {
6357                 if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
6358                         warningf(statement->base.source_position,
6359                                  "'return' without value, in function returning non-void");
6360                 }
6361         }
6362         statement->returns.value = return_value;
6363
6364         return statement;
6365 end_error:
6366         return NULL;
6367 }
6368
6369 /**
6370  * Parse a declaration statement.
6371  */
6372 static statement_t *parse_declaration_statement(void)
6373 {
6374         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
6375
6376         statement->base.source_position = token.source_position;
6377
6378         declaration_t *before = last_declaration;
6379         parse_declaration(record_declaration);
6380
6381         if(before == NULL) {
6382                 statement->declaration.declarations_begin = scope->declarations;
6383         } else {
6384                 statement->declaration.declarations_begin = before->next;
6385         }
6386         statement->declaration.declarations_end = last_declaration;
6387
6388         return statement;
6389 }
6390
6391 /**
6392  * Parse an expression statement, ie. expr ';'.
6393  */
6394 static statement_t *parse_expression_statement(void)
6395 {
6396         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
6397
6398         statement->base.source_position  = token.source_position;
6399         expression_t *const expr         = parse_expression();
6400         statement->expression.expression = expr;
6401
6402         if (warning.unused_value  && !expression_has_effect(expr)) {
6403                 warningf(expr->base.source_position, "statement has no effect");
6404         }
6405
6406         expect(';');
6407
6408         return statement;
6409 end_error:
6410         return NULL;
6411 }
6412
6413 /**
6414  * Parse a statement.
6415  */
6416 static statement_t *parse_statement(void)
6417 {
6418         statement_t   *statement = NULL;
6419
6420         /* declaration or statement */
6421         switch(token.type) {
6422         case T_asm:
6423                 statement = parse_asm_statement();
6424                 break;
6425
6426         case T_case:
6427                 statement = parse_case_statement();
6428                 break;
6429
6430         case T_default:
6431                 statement = parse_default_statement();
6432                 break;
6433
6434         case '{':
6435                 statement = parse_compound_statement();
6436                 break;
6437
6438         case T_if:
6439                 statement = parse_if();
6440                 break;
6441
6442         case T_switch:
6443                 statement = parse_switch();
6444                 break;
6445
6446         case T_while:
6447                 statement = parse_while();
6448                 break;
6449
6450         case T_do:
6451                 statement = parse_do();
6452                 break;
6453
6454         case T_for:
6455                 statement = parse_for();
6456                 break;
6457
6458         case T_goto:
6459                 statement = parse_goto();
6460                 break;
6461
6462         case T_continue:
6463                 statement = parse_continue();
6464                 break;
6465
6466         case T_break:
6467                 statement = parse_break();
6468                 break;
6469
6470         case T_return:
6471                 statement = parse_return();
6472                 break;
6473
6474         case ';':
6475                 if (warning.empty_statement) {
6476                         warningf(HERE, "statement is empty");
6477                 }
6478                 next_token();
6479                 statement = NULL;
6480                 break;
6481
6482         case T_IDENTIFIER:
6483                 if(look_ahead(1)->type == ':') {
6484                         statement = parse_label_statement();
6485                         break;
6486                 }
6487
6488                 if(is_typedef_symbol(token.v.symbol)) {
6489                         statement = parse_declaration_statement();
6490                         break;
6491                 }
6492
6493                 statement = parse_expression_statement();
6494                 break;
6495
6496         case T___extension__:
6497                 /* this can be a prefix to a declaration or an expression statement */
6498                 /* we simply eat it now and parse the rest with tail recursion */
6499                 do {
6500                         next_token();
6501                 } while(token.type == T___extension__);
6502                 statement = parse_statement();
6503                 break;
6504
6505         DECLARATION_START
6506                 statement = parse_declaration_statement();
6507                 break;
6508
6509         default:
6510                 statement = parse_expression_statement();
6511                 break;
6512         }
6513
6514         assert(statement == NULL
6515                         || statement->base.source_position.input_name != NULL);
6516
6517         return statement;
6518 }
6519
6520 /**
6521  * Parse a compound statement.
6522  */
6523 static statement_t *parse_compound_statement(void)
6524 {
6525         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
6526
6527         statement->base.source_position = token.source_position;
6528
6529         eat('{');
6530
6531         int      top        = environment_top();
6532         scope_t *last_scope = scope;
6533         set_scope(&statement->compound.scope);
6534
6535         statement_t *last_statement = NULL;
6536
6537         while(token.type != '}' && token.type != T_EOF) {
6538                 statement_t *sub_statement = parse_statement();
6539                 if(sub_statement == NULL)
6540                         continue;
6541
6542                 if(last_statement != NULL) {
6543                         last_statement->base.next = sub_statement;
6544                 } else {
6545                         statement->compound.statements = sub_statement;
6546                 }
6547
6548                 while(sub_statement->base.next != NULL)
6549                         sub_statement = sub_statement->base.next;
6550
6551                 last_statement = sub_statement;
6552         }
6553
6554         if(token.type == '}') {
6555                 next_token();
6556         } else {
6557                 errorf(statement->base.source_position,
6558                        "end of file while looking for closing '}'");
6559         }
6560
6561         assert(scope == &statement->compound.scope);
6562         set_scope(last_scope);
6563         environment_pop_to(top);
6564
6565         return statement;
6566 }
6567
6568 /**
6569  * Initialize builtin types.
6570  */
6571 static void initialize_builtin_types(void)
6572 {
6573         type_intmax_t    = make_global_typedef("__intmax_t__",      type_long_long);
6574         type_size_t      = make_global_typedef("__SIZE_TYPE__",     type_unsigned_long);
6575         type_ssize_t     = make_global_typedef("__SSIZE_TYPE__",    type_long);
6576         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
6577         type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
6578         type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
6579         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    type_int);
6580         type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
6581
6582         type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
6583         type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
6584         type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
6585         type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
6586 }
6587
6588 /**
6589  * Check for unused global static functions and variables
6590  */
6591 static void check_unused_globals(void)
6592 {
6593         if (!warning.unused_function && !warning.unused_variable)
6594                 return;
6595
6596         for (const declaration_t *decl = global_scope->declarations; decl != NULL; decl = decl->next) {
6597                 if (decl->used || decl->storage_class != STORAGE_CLASS_STATIC)
6598                         continue;
6599
6600                 type_t *const type = decl->type;
6601                 const char *s;
6602                 if (is_type_function(skip_typeref(type))) {
6603                         if (!warning.unused_function || decl->is_inline)
6604                                 continue;
6605
6606                         s = (decl->init.statement != NULL ? "defined" : "declared");
6607                 } else {
6608                         if (!warning.unused_variable)
6609                                 continue;
6610
6611                         s = "defined";
6612                 }
6613
6614                 warningf(decl->source_position, "'%#T' %s but not used",
6615                         type, decl->symbol, s);
6616         }
6617 }
6618
6619 /**
6620  * Parse a translation unit.
6621  */
6622 static translation_unit_t *parse_translation_unit(void)
6623 {
6624         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
6625
6626         assert(global_scope == NULL);
6627         global_scope = &unit->scope;
6628
6629         assert(scope == NULL);
6630         set_scope(&unit->scope);
6631
6632         initialize_builtin_types();
6633
6634         while(token.type != T_EOF) {
6635                 if (token.type == ';') {
6636                         /* TODO error in strict mode */
6637                         warningf(HERE, "stray ';' outside of function");
6638                         next_token();
6639                 } else {
6640                         parse_external_declaration();
6641                 }
6642         }
6643
6644         assert(scope == &unit->scope);
6645         scope          = NULL;
6646         last_declaration = NULL;
6647
6648         assert(global_scope == &unit->scope);
6649         check_unused_globals();
6650         global_scope = NULL;
6651
6652         return unit;
6653 }
6654
6655 /**
6656  * Parse the input.
6657  *
6658  * @return  the translation unit or NULL if errors occurred.
6659  */
6660 translation_unit_t *parse(void)
6661 {
6662         environment_stack = NEW_ARR_F(stack_entry_t, 0);
6663         label_stack       = NEW_ARR_F(stack_entry_t, 0);
6664         diagnostic_count  = 0;
6665         error_count       = 0;
6666         warning_count     = 0;
6667
6668         type_set_output(stderr);
6669         ast_set_output(stderr);
6670
6671         lookahead_bufpos = 0;
6672         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
6673                 next_token();
6674         }
6675         translation_unit_t *unit = parse_translation_unit();
6676
6677         DEL_ARR_F(environment_stack);
6678         DEL_ARR_F(label_stack);
6679
6680         if(error_count > 0)
6681                 return NULL;
6682
6683         return unit;
6684 }
6685
6686 /**
6687  * Initialize the parser.
6688  */
6689 void init_parser(void)
6690 {
6691         init_expression_parsers();
6692         obstack_init(&temp_obst);
6693
6694         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
6695         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
6696 }
6697
6698 /**
6699  * Terminate the parser.
6700  */
6701 void exit_parser(void)
6702 {
6703         obstack_free(&temp_obst, NULL);
6704 }