nsz Git - cparser/blob - parser.c

   1 #include <config.h>
   2
   3 #include <assert.h>
   4 #include <stdarg.h>
   5 #include <stdbool.h>
   6
   7 #include "parser.h"
   8 #include "lexer.h"
   9 #include "token_t.h"
  10 #include "type_t.h"
  11 #include "type_hash.h"
  12 #include "ast_t.h"
  13 #include "adt/bitfiddle.h"
  14 #include "adt/error.h"
  15 #include "adt/array.h"
  16
  17 //#define PRINT_TOKENS
  18 //#define ABORT_ON_ERROR
  19 #define MAX_LOOKAHEAD 2
  20 //#define STRICT_C99
  21
  22 typedef struct {
  23         declaration_t *old_declaration;
  24         symbol_t      *symbol;
  25         unsigned short namespc;
  26 } stack_entry_t;
  27
  28 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  29 struct declaration_specifiers_t {
  30         source_position_t  source_position;
  31         unsigned char      storage_class;
  32         bool               is_inline;
  33         decl_modifiers_t   decl_modifiers;
  34         type_t            *type;
  35 };
  36
  37 typedef declaration_t* (*parsed_declaration_func) (declaration_t *declaration);
  38
  39 static token_t         token;
  40 static token_t         lookahead_buffer[MAX_LOOKAHEAD];
  41 static int             lookahead_bufpos;
  42 static stack_entry_t  *environment_stack = NULL;
  43 static stack_entry_t  *label_stack       = NULL;
  44 static context_t      *global_context    = NULL;
  45 static context_t      *context           = NULL;
  46 static declaration_t  *last_declaration  = NULL;
  47 static declaration_t  *current_function  = NULL;
  48 static struct obstack  temp_obst;
  49 static bool            found_error;
  50
  51 static type_t         *type_int         = NULL;
  52 static type_t         *type_long_double = NULL;
  53 static type_t         *type_double      = NULL;
  54 static type_t         *type_float       = NULL;
  55 static type_t         *type_char        = NULL;
  56 static type_t         *type_string      = NULL;
  57 static type_t         *type_void        = NULL;
  58 static type_t         *type_void_ptr    = NULL;
  59 static type_t         *type_valist      = NULL;
  60
  61 type_t *type_size_t      = NULL;
  62 type_t *type_ptrdiff_t   = NULL;
  63 type_t *type_wchar_t     = NULL;
  64 type_t *type_wchar_t_ptr = NULL;
  65
  66 static statement_t *parse_compound_statement(void);
  67 static statement_t *parse_statement(void);
  68
  69 static expression_t *parse_sub_expression(unsigned precedence);
  70 static expression_t *parse_expression(void);
  71 static type_t       *parse_typename(void);
  72
  73 static void parse_compound_type_entries(void);
  74 static declaration_t *parse_declarator(
  75                 const declaration_specifiers_t *specifiers, bool may_be_abstract);
  76 static declaration_t *record_declaration(declaration_t *declaration);
  77
  78 static void semantic_comparison(binary_expression_t *expression);
  79
  80 #define STORAGE_CLASSES     \
  81         case T_typedef:         \
  82         case T_extern:          \
  83         case T_static:          \
  84         case T_auto:            \
  85         case T_register:
  86
  87 #define TYPE_QUALIFIERS     \
  88         case T_const:           \
  89         case T_restrict:        \
  90         case T_volatile:        \
  91         case T_inline:          \
  92         case T_forceinline:
  93
  94 #ifdef PROVIDE_COMPLEX
  95 #define COMPLEX_SPECIFIERS  \
  96         case T__Complex:
  97 #define IMAGINARY_SPECIFIERS \
  98         case T__Imaginary:
  99 #else
 100 #define COMPLEX_SPECIFIERS
 101 #define IMAGINARY_SPECIFIERS
 102 #endif
 103
 104 #define TYPE_SPECIFIERS       \
 105         case T_void:              \
 106         case T_char:              \
 107         case T_short:             \
 108         case T_int:               \
 109         case T_long:              \
 110         case T_float:             \
 111         case T_double:            \
 112         case T_signed:            \
 113         case T_unsigned:          \
 114         case T__Bool:             \
 115         case T_struct:            \
 116         case T_union:             \
 117         case T_enum:              \
 118         case T___typeof__:        \
 119         case T___builtin_va_list: \
 120         COMPLEX_SPECIFIERS        \
 121         IMAGINARY_SPECIFIERS
 122
 123 #define DECLARATION_START   \
 124         STORAGE_CLASSES         \
 125         TYPE_QUALIFIERS         \
 126         TYPE_SPECIFIERS
 127
 128 #define TYPENAME_START      \
 129         TYPE_QUALIFIERS         \
 130         TYPE_SPECIFIERS
 131
 132 static void *allocate_ast_zero(size_t size)
 133 {
 134         void *res = allocate_ast(size);
 135         memset(res, 0, size);
 136         return res;
 137 }
 138
 139 static size_t get_statement_struct_size(statement_type_t type)
 140 {
 141         static const size_t sizes[] = {
 142                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 143                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 144                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 145                 [STATEMENT_IF]          = sizeof(if_statement_t),
 146                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 147                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 148                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 149                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 150                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 151                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 152                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 153                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 154                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 155                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 156                 [STATEMENT_ASM]         = sizeof(asm_statement_t)
 157         };
 158         assert(type <= sizeof(sizes) / sizeof(sizes[0]));
 159         assert(sizes[type] != 0);
 160         return sizes[type];
 161 }
 162
 163 static statement_t *allocate_statement_zero(statement_type_t type)
 164 {
 165         size_t       size = get_statement_struct_size(type);
 166         statement_t *res  = allocate_ast_zero(size);
 167
 168         res->base.type = type;
 169         return res;
 170 }
 171
 172
 173 static size_t get_expression_struct_size(expression_type_t type)
 174 {
 175         static const size_t sizes[] = {
 176                 [EXPR_INVALID]             = sizeof(expression_base_t),
 177                 [EXPR_REFERENCE]           = sizeof(reference_expression_t),
 178                 [EXPR_CONST]               = sizeof(const_expression_t),
 179                 [EXPR_STRING_LITERAL]      = sizeof(string_literal_expression_t),
 180                 [EXPR_WIDE_STRING_LITERAL] = sizeof(wide_string_literal_expression_t),
 181                 [EXPR_CALL]                = sizeof(call_expression_t),
 182                 [EXPR_UNARY_FIRST]         = sizeof(unary_expression_t),
 183                 [EXPR_BINARY_FIRST]        = sizeof(binary_expression_t),
 184                 [EXPR_CONDITIONAL]         = sizeof(conditional_expression_t),
 185                 [EXPR_SELECT]              = sizeof(select_expression_t),
 186                 [EXPR_ARRAY_ACCESS]        = sizeof(array_access_expression_t),
 187                 [EXPR_SIZEOF]              = sizeof(sizeof_expression_t),
 188                 [EXPR_CLASSIFY_TYPE]       = sizeof(classify_type_expression_t),
 189                 [EXPR_FUNCTION]            = sizeof(string_literal_expression_t),
 190                 [EXPR_PRETTY_FUNCTION]     = sizeof(string_literal_expression_t),
 191                 [EXPR_BUILTIN_SYMBOL]      = sizeof(builtin_symbol_expression_t),
 192                 [EXPR_OFFSETOF]            = sizeof(offsetof_expression_t),
 193                 [EXPR_VA_START]            = sizeof(va_start_expression_t),
 194                 [EXPR_VA_ARG]              = sizeof(va_arg_expression_t),
 195                 [EXPR_STATEMENT]           = sizeof(statement_expression_t),
 196         };
 197         if(type >= EXPR_UNARY_FIRST && type <= EXPR_UNARY_LAST) {
 198                 return sizes[EXPR_UNARY_FIRST];
 199         }
 200         if(type >= EXPR_BINARY_FIRST && type <= EXPR_BINARY_LAST) {
 201                 return sizes[EXPR_BINARY_FIRST];
 202         }
 203         assert(type <= sizeof(sizes) / sizeof(sizes[0]));
 204         assert(sizes[type] != 0);
 205         return sizes[type];
 206 }
 207
 208 static expression_t *allocate_expression_zero(expression_type_t type)
 209 {
 210         size_t        size = get_expression_struct_size(type);
 211         expression_t *res  = allocate_ast_zero(size);
 212
 213         res->base.type = type;
 214         return res;
 215 }
 216
 217 static size_t get_type_struct_size(type_type_t type)
 218 {
 219         static const size_t sizes[] = {
 220                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 221                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 222                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 223                 [TYPE_ENUM]            = sizeof(enum_type_t),
 224                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 225                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 226                 [TYPE_ARRAY]           = sizeof(array_type_t),
 227                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 228                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 229                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 230         };
 231         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 232         assert(type <= TYPE_TYPEOF);
 233         assert(sizes[type] != 0);
 234         return sizes[type];
 235 }
 236
 237 static type_t *allocate_type_zero(type_type_t type)
 238 {
 239         size_t  size = get_type_struct_size(type);
 240         type_t *res  = obstack_alloc(type_obst, size);
 241         memset(res, 0, size);
 242
 243         res->base.type = type;
 244         return res;
 245 }
 246
 247 static size_t get_initializer_size(initializer_type_t type)
 248 {
 249         static const size_t sizes[] = {
 250                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 251                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 252                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 253                 [INITIALIZER_LIST]        = sizeof(initializer_list_t)
 254         };
 255         assert(type < sizeof(sizes) / sizeof(*sizes));
 256         assert(sizes[type] != 0);
 257         return sizes[type];
 258 }
 259
 260 static initializer_t *allocate_initializer(initializer_type_t type)
 261 {
 262         initializer_t *result = allocate_ast_zero(get_initializer_size(type));
 263         result->type          = type;
 264
 265         return result;
 266 }
 267
 268 static void free_type(void *type)
 269 {
 270         obstack_free(type_obst, type);
 271 }
 272
 273 /**
 274  * returns the top element of the environment stack
 275  */
 276 static size_t environment_top(void)
 277 {
 278         return ARR_LEN(environment_stack);
 279 }
 280
 281 static size_t label_top(void)
 282 {
 283         return ARR_LEN(label_stack);
 284 }
 285
 286
 287
 288 static inline void next_token(void)
 289 {
 290         token                              = lookahead_buffer[lookahead_bufpos];
 291         lookahead_buffer[lookahead_bufpos] = lexer_token;
 292         lexer_next_token();
 293
 294         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 295
 296 #ifdef PRINT_TOKENS
 297         print_token(stderr, &token);
 298         fprintf(stderr, "\n");
 299 #endif
 300 }
 301
 302 static inline const token_t *look_ahead(int num)
 303 {
 304         assert(num > 0 && num <= MAX_LOOKAHEAD);
 305         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 306         return &lookahead_buffer[pos];
 307 }
 308
 309 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
 310
 311 static void error(void)
 312 {
 313         found_error = true;
 314 #ifdef ABORT_ON_ERROR
 315         abort();
 316 #endif
 317 }
 318
 319 static void parser_print_prefix_pos(const source_position_t source_position)
 320 {
 321     fputs(source_position.input_name, stderr);
 322     fputc(':', stderr);
 323     fprintf(stderr, "%u", source_position.linenr);
 324     fputs(": ", stderr);
 325 }
 326
 327 static void parser_print_error_prefix_pos(
 328                 const source_position_t source_position)
 329 {
 330         parser_print_prefix_pos(source_position);
 331         fputs("error: ", stderr);
 332         error();
 333 }
 334
 335 static void parser_print_error_prefix(void)
 336 {
 337         parser_print_error_prefix_pos(token.source_position);
 338 }
 339
 340 static void parse_error(const char *message)
 341 {
 342         parser_print_error_prefix();
 343         fprintf(stderr, "parse error: %s\n", message);
 344 }
 345
 346 static void parser_print_warning_prefix_pos(
 347                 const source_position_t source_position)
 348 {
 349         parser_print_prefix_pos(source_position);
 350         fputs("warning: ", stderr);
 351 }
 352
 353 static void parser_print_warning_prefix(void)
 354 {
 355         parser_print_warning_prefix_pos(token.source_position);
 356 }
 357
 358 static void parse_warning_pos(const source_position_t source_position,
 359                               const char *const message)
 360 {
 361         parser_print_prefix_pos(source_position);
 362         fprintf(stderr, "warning: %s\n", message);
 363 }
 364
 365 static void parse_warning(const char *message)
 366 {
 367         parse_warning_pos(token.source_position, message);
 368 }
 369
 370 static void parse_error_expected(const char *message, ...)
 371 {
 372         va_list args;
 373         int first = 1;
 374
 375         if(message != NULL) {
 376                 parser_print_error_prefix();
 377                 fprintf(stderr, "%s\n", message);
 378         }
 379         parser_print_error_prefix();
 380         fputs("Parse error: got ", stderr);
 381         print_token(stderr, &token);
 382         fputs(", expected ", stderr);
 383
 384         va_start(args, message);
 385         token_type_t token_type = va_arg(args, token_type_t);
 386         while(token_type != 0) {
 387                 if(first == 1) {
 388                         first = 0;
 389                 } else {
 390                         fprintf(stderr, ", ");
 391                 }
 392                 print_token_type(stderr, token_type);
 393                 token_type = va_arg(args, token_type_t);
 394         }
 395         va_end(args);
 396         fprintf(stderr, "\n");
 397 }
 398
 399 static void print_type_quoted(type_t *type)
 400 {
 401         fputc('\'', stderr);
 402         print_type(type);
 403         fputc('\'', stderr);
 404 }
 405
 406 static void type_error(const char *msg, const source_position_t source_position,
 407                        type_t *type)
 408 {
 409         parser_print_error_prefix_pos(source_position);
 410         fprintf(stderr, "%s, but found type ", msg);
 411         print_type_quoted(type);
 412         fputc('\n', stderr);
 413 }
 414
 415 static void type_error_incompatible(const char *msg,
 416                 const source_position_t source_position, type_t *type1, type_t *type2)
 417 {
 418         parser_print_error_prefix_pos(source_position);
 419         fprintf(stderr, "%s, incompatible types: ", msg);
 420         print_type_quoted(type1);
 421         fprintf(stderr, " - ");
 422         print_type_quoted(type2);
 423         fprintf(stderr, ")\n");
 424 }
 425
 426 static void eat_block(void)
 427 {
 428         if(token.type == '{')
 429                 next_token();
 430
 431         while(token.type != '}') {
 432                 if(token.type == T_EOF)
 433                         return;
 434                 if(token.type == '{') {
 435                         eat_block();
 436                         continue;
 437                 }
 438                 next_token();
 439         }
 440         eat('}');
 441 }
 442
 443 static void eat_statement(void)
 444 {
 445         while(token.type != ';') {
 446                 if(token.type == T_EOF)
 447                         return;
 448                 if(token.type == '}')
 449                         return;
 450                 if(token.type == '{') {
 451                         eat_block();
 452                         continue;
 453                 }
 454                 next_token();
 455         }
 456         eat(';');
 457 }
 458
 459 static void eat_paren(void)
 460 {
 461         if(token.type == '(')
 462                 next_token();
 463
 464         while(token.type != ')') {
 465                 if(token.type == T_EOF)
 466                         return;
 467                 if(token.type == ')' || token.type == ';' || token.type == '}') {
 468                         return;
 469                 }
 470                 if(token.type == '(') {
 471                         eat_paren();
 472                         continue;
 473                 }
 474                 if(token.type == '{') {
 475                         eat_block();
 476                         continue;
 477                 }
 478                 next_token();
 479         }
 480         eat(')');
 481 }
 482
 483 #define expect(expected)                           \
 484     if(UNLIKELY(token.type != (expected))) {       \
 485         parse_error_expected(NULL, (expected), 0); \
 486         eat_statement();                           \
 487         return NULL;                               \
 488     }                                              \
 489     next_token();
 490
 491 #define expect_block(expected)                     \
 492     if(UNLIKELY(token.type != (expected))) {       \
 493         parse_error_expected(NULL, (expected), 0); \
 494         eat_block();                               \
 495         return NULL;                               \
 496     }                                              \
 497     next_token();
 498
 499 #define expect_void(expected)                      \
 500     if(UNLIKELY(token.type != (expected))) {       \
 501         parse_error_expected(NULL, (expected), 0); \
 502         eat_statement();                           \
 503         return;                                    \
 504     }                                              \
 505     next_token();
 506
 507 static void set_context(context_t *new_context)
 508 {
 509         context = new_context;
 510
 511         last_declaration = new_context->declarations;
 512         if(last_declaration != NULL) {
 513                 while(last_declaration->next != NULL) {
 514                         last_declaration = last_declaration->next;
 515                 }
 516         }
 517 }
 518
 519 /**
 520  * called when we find a 2nd declarator for an identifier we already have a
 521  * declarator for
 522  */
 523 static bool is_compatible_declaration(declaration_t *declaration,
 524                                       declaration_t *previous)
 525 {
 526         /* happens for K&R style function parameters */
 527         if(previous->type == NULL) {
 528                 previous->type = declaration->type;
 529                 return true;
 530         }
 531
 532         type_t *type1 = skip_typeref(declaration->type);
 533         type_t *type2 = skip_typeref(previous->type);
 534
 535         return types_compatible(type1, type2);
 536 }
 537
 538 static declaration_t *get_declaration(symbol_t *symbol, namespace_t namespc)
 539 {
 540         declaration_t *declaration = symbol->declaration;
 541         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 542                 if(declaration->namespc == namespc)
 543                         return declaration;
 544         }
 545
 546         return NULL;
 547 }
 548
 549 static const char *get_namespace_prefix(namespace_t namespc)
 550 {
 551         switch(namespc) {
 552         case NAMESPACE_NORMAL:
 553                 return "";
 554         case NAMESPACE_UNION:
 555                 return "union ";
 556         case NAMESPACE_STRUCT:
 557                 return "struct ";
 558         case NAMESPACE_ENUM:
 559                 return "enum ";
 560         case NAMESPACE_LABEL:
 561                 return "label ";
 562         }
 563         panic("invalid namespace found");
 564 }
 565
 566 /**
 567  * pushs an environment_entry on the environment stack and links the
 568  * corresponding symbol to the new entry
 569  */
 570 static declaration_t *stack_push(stack_entry_t **stack_ptr,
 571                                  declaration_t *declaration,
 572                                  context_t *parent_context)
 573 {
 574         symbol_t    *symbol    = declaration->symbol;
 575         namespace_t  namespc = (namespace_t)declaration->namespc;
 576
 577         /* a declaration should be only pushed once */
 578         declaration->parent_context = parent_context;
 579
 580         declaration_t *previous_declaration = get_declaration(symbol, namespc);
 581         assert(declaration != previous_declaration);
 582         if(previous_declaration != NULL
 583                         && previous_declaration->parent_context == context) {
 584                 if(!is_compatible_declaration(declaration, previous_declaration)) {
 585                         parser_print_error_prefix_pos(declaration->source_position);
 586                         fprintf(stderr, "definition of symbol '%s%s' with type ",
 587                                         get_namespace_prefix(namespc), symbol->string);
 588                         print_type_quoted(declaration->type);
 589                         fputc('\n', stderr);
 590                         parser_print_error_prefix_pos(
 591                                         previous_declaration->source_position);
 592                         fprintf(stderr, "is incompatible with previous declaration "
 593                                         "of type ");
 594                         print_type_quoted(previous_declaration->type);
 595                         fputc('\n', stderr);
 596                 } else {
 597                         unsigned  old_storage_class = previous_declaration->storage_class;
 598                         unsigned  new_storage_class = declaration->storage_class;
 599                         type_t   *type              = previous_declaration->type;
 600                         type = skip_typeref(type);
 601
 602                         if (current_function == NULL) {
 603                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
 604                                     new_storage_class == STORAGE_CLASS_STATIC) {
 605                                         parser_print_error_prefix_pos(declaration->source_position);
 606                                         fprintf(stderr,
 607                                                 "static declaration of '%s' follows non-static declaration\n",
 608                                                 symbol->string);
 609                                         parser_print_error_prefix_pos(previous_declaration->source_position);
 610                                         fprintf(stderr, "previous declaration of '%s' was here\n",
 611                                                 symbol->string);
 612                                 } else {
 613                                         if (old_storage_class == STORAGE_CLASS_EXTERN) {
 614                                                 if (new_storage_class == STORAGE_CLASS_NONE) {
 615                                                         previous_declaration->storage_class = STORAGE_CLASS_NONE;
 616                                                 }
 617                                         } else if(!is_type_function(type)) {
 618                                                 parser_print_warning_prefix_pos(declaration->source_position);
 619                                                 fprintf(stderr, "redundant declaration for '%s'\n",
 620                                                                                 symbol->string);
 621                                                 parser_print_warning_prefix_pos(previous_declaration->source_position);
 622                                                 fprintf(stderr, "previous declaration of '%s' was here\n",
 623                                                                                 symbol->string);
 624                                         }
 625                                 }
 626                         } else {
 627                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
 628                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
 629                                         parser_print_warning_prefix_pos(declaration->source_position);
 630                                         fprintf(stderr, "redundant extern declaration for '%s'\n",
 631                                                 symbol->string);
 632                                         parser_print_warning_prefix_pos(previous_declaration->source_position);
 633                                         fprintf(stderr, "previous declaration of '%s' was here\n",
 634                                                 symbol->string);
 635                                 } else {
 636                                         parser_print_error_prefix_pos(declaration->source_position);
 637                                         if (old_storage_class == new_storage_class) {
 638                                                 fprintf(stderr, "redeclaration of '%s'\n", symbol->string);
 639                                         } else {
 640                                                 fprintf(stderr, "redeclaration of '%s' with different linkage\n", symbol->string);
 641                                         }
 642                                         parser_print_error_prefix_pos(previous_declaration->source_position);
 643                                         fprintf(stderr, "previous declaration of '%s' was here\n",
 644                                                 symbol->string);
 645                                 }
 646                         }
 647                 }
 648                 return previous_declaration;
 649         }
 650
 651         /* remember old declaration */
 652         stack_entry_t entry;
 653         entry.symbol          = symbol;
 654         entry.old_declaration = symbol->declaration;
 655         entry.namespc         = (unsigned short) namespc;
 656         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 657
 658         /* replace/add declaration into declaration list of the symbol */
 659         if(symbol->declaration == NULL) {
 660                 symbol->declaration = declaration;
 661         } else {
 662                 declaration_t *iter_last = NULL;
 663                 declaration_t *iter      = symbol->declaration;
 664                 for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 665                         /* replace an entry? */
 666                         if(iter->namespc == namespc) {
 667                                 if(iter_last == NULL) {
 668                                         symbol->declaration = declaration;
 669                                 } else {
 670                                         iter_last->symbol_next = declaration;
 671                                 }
 672                                 declaration->symbol_next = iter->symbol_next;
 673                                 break;
 674                         }
 675                 }
 676                 if(iter == NULL) {
 677                         assert(iter_last->symbol_next == NULL);
 678                         iter_last->symbol_next = declaration;
 679                 }
 680         }
 681
 682         return declaration;
 683 }
 684
 685 static declaration_t *environment_push(declaration_t *declaration)
 686 {
 687         assert(declaration->source_position.input_name != NULL);
 688         return stack_push(&environment_stack, declaration, context);
 689 }
 690
 691 static declaration_t *label_push(declaration_t *declaration)
 692 {
 693         return stack_push(&label_stack, declaration, &current_function->context);
 694 }
 695
 696 /**
 697  * pops symbols from the environment stack until @p new_top is the top element
 698  */
 699 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 700 {
 701         stack_entry_t *stack = *stack_ptr;
 702         size_t         top   = ARR_LEN(stack);
 703         size_t         i;
 704
 705         assert(new_top <= top);
 706         if(new_top == top)
 707                 return;
 708
 709         for(i = top; i > new_top; --i) {
 710                 stack_entry_t *entry = &stack[i - 1];
 711
 712                 declaration_t *old_declaration = entry->old_declaration;
 713                 symbol_t      *symbol          = entry->symbol;
 714                 namespace_t    namespc         = (namespace_t)entry->namespc;
 715
 716                 /* replace/remove declaration */
 717                 declaration_t *declaration = symbol->declaration;
 718                 assert(declaration != NULL);
 719                 if(declaration->namespc == namespc) {
 720                         if(old_declaration == NULL) {
 721                                 symbol->declaration = declaration->symbol_next;
 722                         } else {
 723                                 symbol->declaration = old_declaration;
 724                         }
 725                 } else {
 726                         declaration_t *iter_last = declaration;
 727                         declaration_t *iter      = declaration->symbol_next;
 728                         for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 729                                 /* replace an entry? */
 730                                 if(iter->namespc == namespc) {
 731                                         assert(iter_last != NULL);
 732                                         iter_last->symbol_next = old_declaration;
 733                                         old_declaration->symbol_next = iter->symbol_next;
 734                                         break;
 735                                 }
 736                         }
 737                         assert(iter != NULL);
 738                 }
 739         }
 740
 741         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 742 }
 743
 744 static void environment_pop_to(size_t new_top)
 745 {
 746         stack_pop_to(&environment_stack, new_top);
 747 }
 748
 749 static void label_pop_to(size_t new_top)
 750 {
 751         stack_pop_to(&label_stack, new_top);
 752 }
 753
 754
 755 static int get_rank(const type_t *type)
 756 {
 757         assert(!is_typeref(type));
 758         /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
 759          * and esp. footnote 108). However we can't fold constants (yet), so we
 760          * can't decide wether unsigned int is possible, while int always works.
 761          * (unsigned int would be preferable when possible... for stuff like
 762          *  struct { enum { ... } bla : 4; } ) */
 763         if(type->type == TYPE_ENUM)
 764                 return ATOMIC_TYPE_INT;
 765
 766         assert(type->type == TYPE_ATOMIC);
 767         const atomic_type_t *atomic_type = &type->atomic;
 768         atomic_type_type_t   atype       = atomic_type->atype;
 769         return atype;
 770 }
 771
 772 static type_t *promote_integer(type_t *type)
 773 {
 774         if(get_rank(type) < ATOMIC_TYPE_INT)
 775                 type = type_int;
 776
 777         return type;
 778 }
 779
 780 static expression_t *create_cast_expression(expression_t *expression,
 781                                             type_t *dest_type)
 782 {
 783         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 784
 785         cast->unary.value   = expression;
 786         cast->base.datatype = dest_type;
 787
 788         return cast;
 789 }
 790
 791 static bool is_null_pointer_constant(const expression_t *expression)
 792 {
 793         /* skip void* cast */
 794         if(expression->type == EXPR_UNARY_CAST
 795                         || expression->type == EXPR_UNARY_CAST_IMPLICIT) {
 796                 expression = expression->unary.value;
 797         }
 798
 799         /* TODO: not correct yet, should be any constant integer expression
 800          * which evaluates to 0 */
 801         if (expression->type != EXPR_CONST)
 802                 return false;
 803
 804         type_t *const type = skip_typeref(expression->base.datatype);
 805         if (!is_type_integer(type))
 806                 return false;
 807
 808         return expression->conste.v.int_value == 0;
 809 }
 810
 811 static expression_t *create_implicit_cast(expression_t *expression,
 812                                           type_t *dest_type)
 813 {
 814         type_t *source_type = expression->base.datatype;
 815
 816         if(source_type == NULL)
 817                 return expression;
 818
 819         source_type = skip_typeref(source_type);
 820         dest_type   = skip_typeref(dest_type);
 821
 822         if(source_type == dest_type)
 823                 return expression;
 824
 825         switch (dest_type->type) {
 826                 case TYPE_ENUM:
 827                         /* TODO warning for implicitly converting to enum */
 828                 case TYPE_ATOMIC:
 829                         if (source_type->type != TYPE_ATOMIC &&
 830                                         source_type->type != TYPE_ENUM) {
 831                                 panic("casting of non-atomic types not implemented yet");
 832                         }
 833
 834                         if(is_type_floating(dest_type) && !is_type_scalar(source_type)) {
 835                                 type_error_incompatible("can't cast types",
 836                                                 expression->base.source_position, source_type,
 837                                                 dest_type);
 838                                 return expression;
 839                         }
 840
 841                         return create_cast_expression(expression, dest_type);
 842
 843                 case TYPE_POINTER:
 844                         switch (source_type->type) {
 845                                 case TYPE_ATOMIC:
 846                                         if (is_null_pointer_constant(expression)) {
 847                                                 return create_cast_expression(expression, dest_type);
 848                                         }
 849                                         break;
 850
 851                                 case TYPE_POINTER:
 852                                         if (pointers_compatible(source_type, dest_type)) {
 853                                                 return create_cast_expression(expression, dest_type);
 854                                         }
 855                                         break;
 856
 857                                 case TYPE_ARRAY: {
 858                                         array_type_t   *array_type   = &source_type->array;
 859                                         pointer_type_t *pointer_type = &dest_type->pointer;
 860                                         if (types_compatible(array_type->element_type,
 861                                                                                  pointer_type->points_to)) {
 862                                                 return create_cast_expression(expression, dest_type);
 863                                         }
 864                                         break;
 865                                 }
 866
 867                                 default:
 868                                         panic("casting of non-atomic types not implemented yet");
 869                         }
 870
 871                         type_error_incompatible("can't implicitly cast types",
 872                                         expression->base.source_position, source_type, dest_type);
 873                         return expression;
 874
 875                 default:
 876                         panic("casting of non-atomic types not implemented yet");
 877         }
 878 }
 879
 880 /** Implements the rules from § 6.5.16.1 */
 881 static void semantic_assign(type_t *orig_type_left, expression_t **right,
 882                             const char *context)
 883 {
 884         type_t *orig_type_right = (*right)->base.datatype;
 885
 886         if(orig_type_right == NULL)
 887                 return;
 888
 889         type_t *const type_left  = skip_typeref(orig_type_left);
 890         type_t *const type_right = skip_typeref(orig_type_right);
 891
 892         if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 893             (is_type_pointer(type_left) && is_null_pointer_constant(*right)) ||
 894             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 895                 && is_type_pointer(type_right))) {
 896                 *right = create_implicit_cast(*right, type_left);
 897                 return;
 898         }
 899
 900         if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
 901                 pointer_type_t *pointer_type_left  = &type_left->pointer;
 902                 pointer_type_t *pointer_type_right = &type_right->pointer;
 903                 type_t         *points_to_left     = pointer_type_left->points_to;
 904                 type_t         *points_to_right    = pointer_type_right->points_to;
 905
 906                 points_to_left  = skip_typeref(points_to_left);
 907                 points_to_right = skip_typeref(points_to_right);
 908
 909                 /* the left type has all qualifiers from the right type */
 910                 unsigned missing_qualifiers
 911                         = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 912                 if(missing_qualifiers != 0) {
 913                         parser_print_error_prefix();
 914                         fprintf(stderr, "destination type ");
 915                         print_type_quoted(type_left);
 916                         fprintf(stderr, " in %s from type ", context);
 917                         print_type_quoted(type_right);
 918                         fprintf(stderr, " lacks qualifiers '");
 919                         print_type_qualifiers(missing_qualifiers);
 920                         fprintf(stderr, "' in pointed-to type\n");
 921                         return;
 922                 }
 923
 924                 points_to_left  = get_unqualified_type(points_to_left);
 925                 points_to_right = get_unqualified_type(points_to_right);
 926
 927                 if(!is_type_atomic(points_to_left, ATOMIC_TYPE_VOID)
 928                                 && !is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)
 929                                 && !types_compatible(points_to_left, points_to_right)) {
 930                         goto incompatible_assign_types;
 931                 }
 932
 933                 *right = create_implicit_cast(*right, type_left);
 934                 return;
 935         }
 936
 937         if (is_type_compound(type_left)
 938                         && types_compatible(type_left, type_right)) {
 939                 *right = create_implicit_cast(*right, type_left);
 940                 return;
 941         }
 942
 943 incompatible_assign_types:
 944         /* TODO: improve error message */
 945         parser_print_error_prefix();
 946         fprintf(stderr, "incompatible types in %s\n", context);
 947         parser_print_error_prefix();
 948         print_type_quoted(orig_type_left);
 949         fputs(" <- ", stderr);
 950         print_type_quoted(orig_type_right);
 951         fputs("\n", stderr);
 952 }
 953
 954 static expression_t *parse_constant_expression(void)
 955 {
 956         /* start parsing at precedence 7 (conditional expression) */
 957         return parse_sub_expression(7);
 958 }
 959
 960 static expression_t *parse_assignment_expression(void)
 961 {
 962         /* start parsing at precedence 2 (assignment expression) */
 963         return parse_sub_expression(2);
 964 }
 965
 966 static type_t *make_global_typedef(const char *name, type_t *type)
 967 {
 968         symbol_t *symbol       = symbol_table_insert(name);
 969
 970         declaration_t *declaration   = allocate_ast_zero(sizeof(declaration[0]));
 971         declaration->namespc         = NAMESPACE_NORMAL;
 972         declaration->storage_class   = STORAGE_CLASS_TYPEDEF;
 973         declaration->type            = type;
 974         declaration->symbol          = symbol;
 975         declaration->source_position = builtin_source_position;
 976
 977         record_declaration(declaration);
 978
 979         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF);
 980         typedef_type->typedeft.declaration = declaration;
 981
 982         return typedef_type;
 983 }
 984
 985 static const char *parse_string_literals(void)
 986 {
 987         assert(token.type == T_STRING_LITERAL);
 988         const char *result = token.v.string;
 989
 990         next_token();
 991
 992         while(token.type == T_STRING_LITERAL) {
 993                 result = concat_strings(result, token.v.string);
 994                 next_token();
 995         }
 996
 997         return result;
 998 }
 999
1000 static void parse_attributes(void)
1001 {
1002         while(true) {
1003                 switch(token.type) {
1004                 case T___attribute__: {
1005                         next_token();
1006
1007                         expect_void('(');
1008                         int depth = 1;
1009                         while(depth > 0) {
1010                                 switch(token.type) {
1011                                 case T_EOF:
1012                                         parse_error("EOF while parsing attribute");
1013                                         break;
1014                                 case '(':
1015                                         next_token();
1016                                         depth++;
1017                                         break;
1018                                 case ')':
1019                                         next_token();
1020                                         depth--;
1021                                         break;
1022                                 default:
1023                                         next_token();
1024                                 }
1025                         }
1026                         break;
1027                 }
1028                 case T_asm:
1029                         next_token();
1030                         expect_void('(');
1031                         if(token.type != T_STRING_LITERAL) {
1032                                 parse_error_expected("while parsing assembler attribute",
1033                                                      T_STRING_LITERAL);
1034                                 eat_paren();
1035                                 break;
1036                         } else {
1037                                 parse_string_literals();
1038                         }
1039                         expect_void(')');
1040                         break;
1041                 default:
1042                         goto attributes_finished;
1043                 }
1044         }
1045
1046 attributes_finished:
1047         ;
1048 }
1049
1050 #if 0
1051 static designator_t *parse_designation(void)
1052 {
1053         if(token.type != '[' && token.type != '.')
1054                 return NULL;
1055
1056         designator_t *result = NULL;
1057         designator_t *last   = NULL;
1058
1059         while(1) {
1060                 designator_t *designator;
1061                 switch(token.type) {
1062                 case '[':
1063                         designator = allocate_ast_zero(sizeof(designator[0]));
1064                         next_token();
1065                         designator->array_access = parse_constant_expression();
1066                         expect(']');
1067                         break;
1068                 case '.':
1069                         designator = allocate_ast_zero(sizeof(designator[0]));
1070                         next_token();
1071                         if(token.type != T_IDENTIFIER) {
1072                                 parse_error_expected("while parsing designator",
1073                                                      T_IDENTIFIER, 0);
1074                                 return NULL;
1075                         }
1076                         designator->symbol = token.v.symbol;
1077                         next_token();
1078                         break;
1079                 default:
1080                         expect('=');
1081                         return result;
1082                 }
1083
1084                 assert(designator != NULL);
1085                 if(last != NULL) {
1086                         last->next = designator;
1087                 } else {
1088                         result = designator;
1089                 }
1090                 last = designator;
1091         }
1092 }
1093 #endif
1094
1095 static initializer_t *initializer_from_string(array_type_t *type,
1096                                               const char *string)
1097 {
1098         /* TODO: check len vs. size of array type */
1099         (void) type;
1100
1101         initializer_t *initializer = allocate_initializer(INITIALIZER_STRING);
1102         initializer->string.string = string;
1103
1104         return initializer;
1105 }
1106
1107 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1108                                                    wide_string_t *const string)
1109 {
1110         /* TODO: check len vs. size of array type */
1111         (void) type;
1112
1113         initializer_t *const initializer =
1114                 allocate_initializer(INITIALIZER_WIDE_STRING);
1115         initializer->wide_string.string = *string;
1116
1117         return initializer;
1118 }
1119
1120 static initializer_t *initializer_from_expression(type_t *type,
1121                                                   expression_t *expression)
1122 {
1123         /* TODO check that expression is a constant expression */
1124
1125         /* § 6.7.8.14/15 char array may be initialized by string literals */
1126         type_t *const expr_type = expression->base.datatype;
1127         if (is_type_array(type) && expr_type->type == TYPE_POINTER) {
1128                 array_type_t *const array_type     = &type->array;
1129                 type_t       *const element_type   = skip_typeref(array_type->element_type);
1130
1131                 if (element_type->type == TYPE_ATOMIC) {
1132                         switch (expression->type) {
1133                                 case EXPR_STRING_LITERAL:
1134                                         if (element_type->atomic.atype == ATOMIC_TYPE_CHAR) {
1135                                                 return initializer_from_string(array_type,
1136                                                         expression->string.value);
1137                                         }
1138
1139                                 case EXPR_WIDE_STRING_LITERAL: {
1140                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1141                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1142                                                 return initializer_from_wide_string(array_type,
1143                                                         &expression->wide_string.value);
1144                                         }
1145                                 }
1146
1147                                 default: break;
1148                         }
1149                 }
1150         }
1151
1152         type_t *expression_type = skip_typeref(expression->base.datatype);
1153         if(is_type_scalar(type) || types_compatible(type, expression_type)) {
1154                 semantic_assign(type, &expression, "initializer");
1155
1156                 initializer_t *result = allocate_initializer(INITIALIZER_VALUE);
1157                 result->value.value   = expression;
1158
1159                 return result;
1160         }
1161
1162         return NULL;
1163 }
1164
1165 static initializer_t *parse_sub_initializer(type_t *type,
1166                                             expression_t *expression,
1167                                             type_t *expression_type);
1168
1169 static initializer_t *parse_sub_initializer_elem(type_t *type)
1170 {
1171         if(token.type == '{') {
1172                 return parse_sub_initializer(type, NULL, NULL);
1173         }
1174
1175         expression_t *expression      = parse_assignment_expression();
1176         type_t       *expression_type = skip_typeref(expression->base.datatype);
1177
1178         return parse_sub_initializer(type, expression, expression_type);
1179 }
1180
1181 static bool had_initializer_brace_warning;
1182
1183 static initializer_t *parse_sub_initializer(type_t *type,
1184                                             expression_t *expression,
1185                                             type_t *expression_type)
1186 {
1187         if(is_type_scalar(type)) {
1188                 /* there might be extra {} hierarchies */
1189                 if(token.type == '{') {
1190                         next_token();
1191                         if(!had_initializer_brace_warning) {
1192                                 parse_warning("braces around scalar initializer");
1193                                 had_initializer_brace_warning = true;
1194                         }
1195                         initializer_t *result = parse_sub_initializer(type, NULL, NULL);
1196                         if(token.type == ',') {
1197                                 next_token();
1198                                 /* TODO: warn about excessive elements */
1199                         }
1200                         expect_block('}');
1201                         return result;
1202                 }
1203
1204                 if(expression == NULL) {
1205                         expression = parse_assignment_expression();
1206                 }
1207                 return initializer_from_expression(type, expression);
1208         }
1209
1210         /* does the expression match the currently looked at object to initalize */
1211         if(expression != NULL) {
1212                 initializer_t *result = initializer_from_expression(type, expression);
1213                 if(result != NULL)
1214                         return result;
1215         }
1216
1217         bool read_paren = false;
1218         if(token.type == '{') {
1219                 next_token();
1220                 read_paren = true;
1221         }
1222
1223         /* descend into subtype */
1224         initializer_t  *result = NULL;
1225         initializer_t **elems;
1226         if(is_type_array(type)) {
1227                 array_type_t *array_type   = &type->array;
1228                 type_t       *element_type = array_type->element_type;
1229                 element_type               = skip_typeref(element_type);
1230
1231                 initializer_t *sub;
1232                 had_initializer_brace_warning = false;
1233                 if(expression == NULL) {
1234                         sub = parse_sub_initializer_elem(element_type);
1235                 } else {
1236                         sub = parse_sub_initializer(element_type, expression,
1237                                                     expression_type);
1238                 }
1239
1240                 /* didn't match the subtypes -> try the parent type */
1241                 if(sub == NULL) {
1242                         assert(!read_paren);
1243                         return NULL;
1244                 }
1245
1246                 elems = NEW_ARR_F(initializer_t*, 0);
1247                 ARR_APP1(initializer_t*, elems, sub);
1248
1249                 while(true) {
1250                         if(token.type == '}')
1251                                 break;
1252                         expect_block(',');
1253                         if(token.type == '}')
1254                                 break;
1255
1256                         sub = parse_sub_initializer_elem(element_type);
1257                         if(sub == NULL) {
1258                                 /* TODO error, do nicer cleanup */
1259                                 parse_error("member initializer didn't match");
1260                                 DEL_ARR_F(elems);
1261                                 return NULL;
1262                         }
1263                         ARR_APP1(initializer_t*, elems, sub);
1264                 }
1265         } else {
1266                 assert(is_type_compound(type));
1267                 compound_type_t *compound_type = &type->compound;
1268                 context_t       *context       = &compound_type->declaration->context;
1269
1270                 declaration_t *first = context->declarations;
1271                 if(first == NULL)
1272                         return NULL;
1273                 type_t *first_type = first->type;
1274                 first_type         = skip_typeref(first_type);
1275
1276                 initializer_t *sub;
1277                 had_initializer_brace_warning = false;
1278                 if(expression == NULL) {
1279                         sub = parse_sub_initializer_elem(first_type);
1280                 } else {
1281                         sub = parse_sub_initializer(first_type, expression,expression_type);
1282                 }
1283
1284                 /* didn't match the subtypes -> try our parent type */
1285                 if(sub == NULL) {
1286                         assert(!read_paren);
1287                         return NULL;
1288                 }
1289
1290                 elems = NEW_ARR_F(initializer_t*, 0);
1291                 ARR_APP1(initializer_t*, elems, sub);
1292
1293                 declaration_t *iter  = first->next;
1294                 for( ; iter != NULL; iter = iter->next) {
1295                         if(iter->symbol == NULL)
1296                                 continue;
1297                         if(iter->namespc != NAMESPACE_NORMAL)
1298                                 continue;
1299
1300                         if(token.type == '}')
1301                                 break;
1302                         expect_block(',');
1303                         if(token.type == '}')
1304                                 break;
1305
1306                         type_t *iter_type = iter->type;
1307                         iter_type         = skip_typeref(iter_type);
1308
1309                         sub = parse_sub_initializer_elem(iter_type);
1310                         if(sub == NULL) {
1311                                 /* TODO error, do nicer cleanup*/
1312                                 parse_error("member initializer didn't match");
1313                                 DEL_ARR_F(elems);
1314                                 return NULL;
1315                         }
1316                         ARR_APP1(initializer_t*, elems, sub);
1317                 }
1318         }
1319
1320         int    len        = ARR_LEN(elems);
1321         size_t elems_size = sizeof(initializer_t*) * len;
1322
1323         initializer_list_t *init = allocate_ast_zero(sizeof(init[0]) + elems_size);
1324
1325         init->initializer.type = INITIALIZER_LIST;
1326         init->len              = len;
1327         memcpy(init->initializers, elems, elems_size);
1328         DEL_ARR_F(elems);
1329
1330         result = (initializer_t*) init;
1331
1332         if(read_paren) {
1333                 if(token.type == ',')
1334                         next_token();
1335                 expect('}');
1336         }
1337         return result;
1338 }
1339
1340 static initializer_t *parse_initializer(type_t *type)
1341 {
1342         initializer_t *result;
1343
1344         type = skip_typeref(type);
1345
1346         if(token.type != '{') {
1347                 expression_t  *expression  = parse_assignment_expression();
1348                 initializer_t *initializer = initializer_from_expression(type, expression);
1349                 if(initializer == NULL) {
1350                         parser_print_error_prefix();
1351                         fprintf(stderr, "initializer expression '");
1352                         print_expression(expression);
1353                         fprintf(stderr, "', type ");
1354                         print_type_quoted(expression->base.datatype);
1355                         fprintf(stderr, " is incompatible with type ");
1356                         print_type_quoted(type);
1357                         fprintf(stderr, "\n");
1358                 }
1359                 return initializer;
1360         }
1361
1362         if(is_type_scalar(type)) {
1363                 /* § 6.7.8.11 */
1364                 eat('{');
1365
1366                 expression_t *expression = parse_assignment_expression();
1367                 result = initializer_from_expression(type, expression);
1368
1369                 if(token.type == ',')
1370                         next_token();
1371
1372                 expect('}');
1373                 return result;
1374         } else {
1375                 result = parse_sub_initializer(type, NULL, NULL);
1376         }
1377
1378         return result;
1379 }
1380
1381
1382
1383 static declaration_t *parse_compound_type_specifier(bool is_struct)
1384 {
1385         if(is_struct) {
1386                 eat(T_struct);
1387         } else {
1388                 eat(T_union);
1389         }
1390
1391         symbol_t      *symbol      = NULL;
1392         declaration_t *declaration = NULL;
1393
1394         if (token.type == T___attribute__) {
1395                 /* TODO */
1396                 parse_attributes();
1397         }
1398
1399         if(token.type == T_IDENTIFIER) {
1400                 symbol = token.v.symbol;
1401                 next_token();
1402
1403                 if(is_struct) {
1404                         declaration = get_declaration(symbol, NAMESPACE_STRUCT);
1405                 } else {
1406                         declaration = get_declaration(symbol, NAMESPACE_UNION);
1407                 }
1408         } else if(token.type != '{') {
1409                 if(is_struct) {
1410                         parse_error_expected("while parsing struct type specifier",
1411                                              T_IDENTIFIER, '{', 0);
1412                 } else {
1413                         parse_error_expected("while parsing union type specifier",
1414                                              T_IDENTIFIER, '{', 0);
1415                 }
1416
1417                 return NULL;
1418         }
1419
1420         if(declaration == NULL) {
1421                 declaration = allocate_ast_zero(sizeof(declaration[0]));
1422
1423                 if(is_struct) {
1424                         declaration->namespc = NAMESPACE_STRUCT;
1425                 } else {
1426                         declaration->namespc = NAMESPACE_UNION;
1427                 }
1428                 declaration->source_position = token.source_position;
1429                 declaration->symbol          = symbol;
1430                 record_declaration(declaration);
1431         }
1432
1433         if(token.type == '{') {
1434                 if(declaration->init.is_defined) {
1435                         assert(symbol != NULL);
1436                         parser_print_error_prefix();
1437                         fprintf(stderr, "multiple definition of %s %s\n",
1438                                         is_struct ? "struct" : "union", symbol->string);
1439                         declaration->context.declarations = NULL;
1440                 }
1441                 declaration->init.is_defined = true;
1442
1443                 int         top          = environment_top();
1444                 context_t  *last_context = context;
1445                 set_context(&declaration->context);
1446
1447                 parse_compound_type_entries();
1448                 parse_attributes();
1449
1450                 assert(context == &declaration->context);
1451                 set_context(last_context);
1452                 environment_pop_to(top);
1453         }
1454
1455         return declaration;
1456 }
1457
1458 static void parse_enum_entries(enum_type_t *const enum_type)
1459 {
1460         eat('{');
1461
1462         if(token.type == '}') {
1463                 next_token();
1464                 parse_error("empty enum not allowed");
1465                 return;
1466         }
1467
1468         do {
1469                 declaration_t *entry = allocate_ast_zero(sizeof(entry[0]));
1470
1471                 if(token.type != T_IDENTIFIER) {
1472                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, 0);
1473                         eat_block();
1474                         return;
1475                 }
1476                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
1477                 entry->type            = (type_t*) enum_type;
1478                 entry->symbol          = token.v.symbol;
1479                 entry->source_position = token.source_position;
1480                 next_token();
1481
1482                 if(token.type == '=') {
1483                         next_token();
1484                         entry->init.enum_value = parse_constant_expression();
1485
1486                         /* TODO semantic */
1487                 }
1488
1489                 record_declaration(entry);
1490
1491                 if(token.type != ',')
1492                         break;
1493                 next_token();
1494         } while(token.type != '}');
1495
1496         expect_void('}');
1497 }
1498
1499 static type_t *parse_enum_specifier(void)
1500 {
1501         eat(T_enum);
1502
1503         declaration_t *declaration;
1504         symbol_t      *symbol;
1505
1506         if(token.type == T_IDENTIFIER) {
1507                 symbol = token.v.symbol;
1508                 next_token();
1509
1510                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1511         } else if(token.type != '{') {
1512                 parse_error_expected("while parsing enum type specifier",
1513                                      T_IDENTIFIER, '{', 0);
1514                 return NULL;
1515         } else {
1516                 declaration = NULL;
1517                 symbol      = NULL;
1518         }
1519
1520         if(declaration == NULL) {
1521                 declaration = allocate_ast_zero(sizeof(declaration[0]));
1522
1523                 declaration->namespc       = NAMESPACE_ENUM;
1524                 declaration->source_position = token.source_position;
1525                 declaration->symbol          = symbol;
1526         }
1527
1528         type_t *const type      = allocate_type_zero(TYPE_ENUM);
1529         type->enumt.declaration = declaration;
1530
1531         if(token.type == '{') {
1532                 if(declaration->init.is_defined) {
1533                         parser_print_error_prefix();
1534                         fprintf(stderr, "multiple definitions of enum %s\n",
1535                                 symbol->string);
1536                 }
1537                 record_declaration(declaration);
1538                 declaration->init.is_defined = 1;
1539
1540                 parse_enum_entries(&type->enumt);
1541                 parse_attributes();
1542         }
1543
1544         return type;
1545 }
1546
1547 /**
1548  * if a symbol is a typedef to another type, return true
1549  */
1550 static bool is_typedef_symbol(symbol_t *symbol)
1551 {
1552         const declaration_t *const declaration =
1553                 get_declaration(symbol, NAMESPACE_NORMAL);
1554         return
1555                 declaration != NULL &&
1556                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1557 }
1558
1559 static type_t *parse_typeof(void)
1560 {
1561         eat(T___typeof__);
1562
1563         type_t *type;
1564
1565         expect('(');
1566
1567         expression_t *expression  = NULL;
1568
1569 restart:
1570         switch(token.type) {
1571         case T___extension__:
1572                 /* this can be a prefix to a typename or an expression */
1573                 /* we simply eat it now. */
1574                 do {
1575                         next_token();
1576                 } while(token.type == T___extension__);
1577                 goto restart;
1578
1579         case T_IDENTIFIER:
1580                 if(is_typedef_symbol(token.v.symbol)) {
1581                         type = parse_typename();
1582                 } else {
1583                         expression = parse_expression();
1584                         type       = expression->base.datatype;
1585                 }
1586                 break;
1587
1588         TYPENAME_START
1589                 type = parse_typename();
1590                 break;
1591
1592         default:
1593                 expression = parse_expression();
1594                 type       = expression->base.datatype;
1595                 break;
1596         }
1597
1598         expect(')');
1599
1600         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
1601         typeof_type->typeoft.expression  = expression;
1602         typeof_type->typeoft.typeof_type = type;
1603
1604         return typeof_type;
1605 }
1606
1607 typedef enum {
1608         SPECIFIER_SIGNED    = 1 << 0,
1609         SPECIFIER_UNSIGNED  = 1 << 1,
1610         SPECIFIER_LONG      = 1 << 2,
1611         SPECIFIER_INT       = 1 << 3,
1612         SPECIFIER_DOUBLE    = 1 << 4,
1613         SPECIFIER_CHAR      = 1 << 5,
1614         SPECIFIER_SHORT     = 1 << 6,
1615         SPECIFIER_LONG_LONG = 1 << 7,
1616         SPECIFIER_FLOAT     = 1 << 8,
1617         SPECIFIER_BOOL      = 1 << 9,
1618         SPECIFIER_VOID      = 1 << 10,
1619 #ifdef PROVIDE_COMPLEX
1620         SPECIFIER_COMPLEX   = 1 << 11,
1621         SPECIFIER_IMAGINARY = 1 << 12,
1622 #endif
1623 } specifiers_t;
1624
1625 static type_t *create_builtin_type(symbol_t *const symbol,
1626                                    type_t *const real_type)
1627 {
1628         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
1629         type->builtin.symbol    = symbol;
1630         type->builtin.real_type = real_type;
1631
1632         type_t *result = typehash_insert(type);
1633         if (type != result) {
1634                 free_type(type);
1635         }
1636
1637         return result;
1638 }
1639
1640 static type_t *get_typedef_type(symbol_t *symbol)
1641 {
1642         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1643         if(declaration == NULL
1644                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1645                 return NULL;
1646
1647         type_t *type               = allocate_type_zero(TYPE_TYPEDEF);
1648         type->typedeft.declaration = declaration;
1649
1650         return type;
1651 }
1652
1653 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1654 {
1655         type_t   *type            = NULL;
1656         unsigned  type_qualifiers = 0;
1657         unsigned  type_specifiers = 0;
1658         int       newtype         = 0;
1659
1660         specifiers->source_position = token.source_position;
1661
1662         while(true) {
1663                 switch(token.type) {
1664
1665                 /* storage class */
1666 #define MATCH_STORAGE_CLASS(token, class)                                \
1667                 case token:                                                      \
1668                         if(specifiers->storage_class != STORAGE_CLASS_NONE) {        \
1669                                 parse_error("multiple storage classes in declaration "   \
1670                                             "specifiers");                               \
1671                         }                                                            \
1672                         specifiers->storage_class = class;                           \
1673                         next_token();                                                \
1674                         break;
1675
1676                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1677                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1678                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1679                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1680                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1681
1682                 case T___thread:
1683                         switch (specifiers->storage_class) {
1684                                 case STORAGE_CLASS_NONE:
1685                                         specifiers->storage_class = STORAGE_CLASS_THREAD;
1686                                         break;
1687
1688                                 case STORAGE_CLASS_EXTERN:
1689                                         specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
1690                                         break;
1691
1692                                 case STORAGE_CLASS_STATIC:
1693                                         specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
1694                                         break;
1695
1696                                 default:
1697                                         parse_error("multiple storage classes in declaration specifiers");
1698                                         break;
1699                         }
1700                         next_token();
1701                         break;
1702
1703                 /* type qualifiers */
1704 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1705                 case token:                                                     \
1706                         type_qualifiers |= qualifier;                               \
1707                         next_token();                                               \
1708                         break;
1709
1710                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1711                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1712                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1713
1714                 case T___extension__:
1715                         /* TODO */
1716                         next_token();
1717                         break;
1718
1719                 /* type specifiers */
1720 #define MATCH_SPECIFIER(token, specifier, name)                         \
1721                 case token:                                                     \
1722                         next_token();                                               \
1723                         if(type_specifiers & specifier) {                           \
1724                                 parse_error("multiple " name " type specifiers given"); \
1725                         } else {                                                    \
1726                                 type_specifiers |= specifier;                           \
1727                         }                                                           \
1728                         break;
1729
1730                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
1731                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
1732                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
1733                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
1734                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
1735                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
1736                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
1737                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
1738                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
1739 #ifdef PROVIDE_COMPLEX
1740                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
1741                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
1742 #endif
1743                 case T_forceinline:
1744                         /* only in microsoft mode */
1745                         specifiers->decl_modifiers |= DM_FORCEINLINE;
1746
1747                 case T_inline:
1748                         next_token();
1749                         specifiers->is_inline = true;
1750                         break;
1751
1752                 case T_long:
1753                         next_token();
1754                         if(type_specifiers & SPECIFIER_LONG_LONG) {
1755                                 parse_error("multiple type specifiers given");
1756                         } else if(type_specifiers & SPECIFIER_LONG) {
1757                                 type_specifiers |= SPECIFIER_LONG_LONG;
1758                         } else {
1759                                 type_specifiers |= SPECIFIER_LONG;
1760                         }
1761                         break;
1762
1763                 /* TODO: if type != NULL for the following rules should issue
1764                  * an error */
1765                 case T_struct: {
1766                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1767
1768                         type->compound.declaration = parse_compound_type_specifier(true);
1769                         break;
1770                 }
1771                 case T_union: {
1772                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1773
1774                         type->compound.declaration = parse_compound_type_specifier(false);
1775                         break;
1776                 }
1777                 case T_enum:
1778                         type = parse_enum_specifier();
1779                         break;
1780                 case T___typeof__:
1781                         type = parse_typeof();
1782                         break;
1783                 case T___builtin_va_list:
1784                         type = duplicate_type(type_valist);
1785                         next_token();
1786                         break;
1787
1788                 case T___attribute__:
1789                         /* TODO */
1790                         parse_attributes();
1791                         break;
1792
1793                 case T_IDENTIFIER: {
1794                         type_t *typedef_type = get_typedef_type(token.v.symbol);
1795
1796                         if(typedef_type == NULL)
1797                                 goto finish_specifiers;
1798
1799                         next_token();
1800                         type = typedef_type;
1801                         break;
1802                 }
1803
1804                 /* function specifier */
1805                 default:
1806                         goto finish_specifiers;
1807                 }
1808         }
1809
1810 finish_specifiers:
1811
1812         if(type == NULL) {
1813                 atomic_type_type_t atomic_type;
1814
1815                 /* match valid basic types */
1816                 switch(type_specifiers) {
1817                 case SPECIFIER_VOID:
1818                         atomic_type = ATOMIC_TYPE_VOID;
1819                         break;
1820                 case SPECIFIER_CHAR:
1821                         atomic_type = ATOMIC_TYPE_CHAR;
1822                         break;
1823                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
1824                         atomic_type = ATOMIC_TYPE_SCHAR;
1825                         break;
1826                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
1827                         atomic_type = ATOMIC_TYPE_UCHAR;
1828                         break;
1829                 case SPECIFIER_SHORT:
1830                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
1831                 case SPECIFIER_SHORT | SPECIFIER_INT:
1832                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1833                         atomic_type = ATOMIC_TYPE_SHORT;
1834                         break;
1835                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
1836                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1837                         atomic_type = ATOMIC_TYPE_USHORT;
1838                         break;
1839                 case SPECIFIER_INT:
1840                 case SPECIFIER_SIGNED:
1841                 case SPECIFIER_SIGNED | SPECIFIER_INT:
1842                         atomic_type = ATOMIC_TYPE_INT;
1843                         break;
1844                 case SPECIFIER_UNSIGNED:
1845                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
1846                         atomic_type = ATOMIC_TYPE_UINT;
1847                         break;
1848                 case SPECIFIER_LONG:
1849                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
1850                 case SPECIFIER_LONG | SPECIFIER_INT:
1851                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1852                         atomic_type = ATOMIC_TYPE_LONG;
1853                         break;
1854                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
1855                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1856                         atomic_type = ATOMIC_TYPE_ULONG;
1857                         break;
1858                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1859                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1860                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
1861                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1862                         | SPECIFIER_INT:
1863                         atomic_type = ATOMIC_TYPE_LONGLONG;
1864                         break;
1865                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1866                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1867                         | SPECIFIER_INT:
1868                         atomic_type = ATOMIC_TYPE_ULONGLONG;
1869                         break;
1870                 case SPECIFIER_FLOAT:
1871                         atomic_type = ATOMIC_TYPE_FLOAT;
1872                         break;
1873                 case SPECIFIER_DOUBLE:
1874                         atomic_type = ATOMIC_TYPE_DOUBLE;
1875                         break;
1876                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
1877                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
1878                         break;
1879                 case SPECIFIER_BOOL:
1880                         atomic_type = ATOMIC_TYPE_BOOL;
1881                         break;
1882 #ifdef PROVIDE_COMPLEX
1883                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
1884                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
1885                         break;
1886                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1887                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
1888                         break;
1889                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1890                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
1891                         break;
1892                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
1893                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
1894                         break;
1895                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1896                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
1897                         break;
1898                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1899                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
1900                         break;
1901 #endif
1902                 default:
1903                         /* invalid specifier combination, give an error message */
1904                         if(type_specifiers == 0) {
1905 #ifndef STRICT_C99
1906                                 parse_warning("no type specifiers in declaration, using int");
1907                                 atomic_type = ATOMIC_TYPE_INT;
1908                                 break;
1909 #else
1910                                 parse_error("no type specifiers given in declaration");
1911 #endif
1912                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
1913                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
1914                                 parse_error("signed and unsigned specifiers gives");
1915                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
1916                                 parse_error("only integer types can be signed or unsigned");
1917                         } else {
1918                                 parse_error("multiple datatypes in declaration");
1919                         }
1920                         atomic_type = ATOMIC_TYPE_INVALID;
1921                 }
1922
1923                 type               = allocate_type_zero(TYPE_ATOMIC);
1924                 type->atomic.atype = atomic_type;
1925                 newtype            = 1;
1926         } else {
1927                 if(type_specifiers != 0) {
1928                         parse_error("multiple datatypes in declaration");
1929                 }
1930         }
1931
1932         type->base.qualifiers = type_qualifiers;
1933
1934         type_t *result = typehash_insert(type);
1935         if(newtype && result != type) {
1936                 free_type(type);
1937         }
1938
1939         specifiers->type = result;
1940 }
1941
1942 static type_qualifiers_t parse_type_qualifiers(void)
1943 {
1944         type_qualifiers_t type_qualifiers = TYPE_QUALIFIER_NONE;
1945
1946         while(true) {
1947                 switch(token.type) {
1948                 /* type qualifiers */
1949                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1950                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1951                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1952
1953                 default:
1954                         return type_qualifiers;
1955                 }
1956         }
1957 }
1958
1959 static declaration_t *parse_identifier_list(void)
1960 {
1961         declaration_t *declarations     = NULL;
1962         declaration_t *last_declaration = NULL;
1963         do {
1964                 declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
1965
1966                 declaration->source_position = token.source_position;
1967                 declaration->symbol          = token.v.symbol;
1968                 next_token();
1969
1970                 if(last_declaration != NULL) {
1971                         last_declaration->next = declaration;
1972                 } else {
1973                         declarations = declaration;
1974                 }
1975                 last_declaration = declaration;
1976
1977                 if(token.type != ',')
1978                         break;
1979                 next_token();
1980         } while(token.type == T_IDENTIFIER);
1981
1982         return declarations;
1983 }
1984
1985 static void semantic_parameter(declaration_t *declaration)
1986 {
1987         /* TODO: improve error messages */
1988
1989         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
1990                 parse_error("typedef not allowed in parameter list");
1991         } else if(declaration->storage_class != STORAGE_CLASS_NONE
1992                         && declaration->storage_class != STORAGE_CLASS_REGISTER) {
1993                 parse_error("parameter may only have none or register storage class");
1994         }
1995
1996         type_t *orig_type = declaration->type;
1997         if(orig_type == NULL)
1998                 return;
1999         type_t *type = skip_typeref(orig_type);
2000
2001         /* Array as last part of a paramter type is just syntactic sugar.  Turn it
2002          * into a pointer. § 6.7.5.3 (7) */
2003         if (is_type_array(type)) {
2004                 const array_type_t *arr_type     = &type->array;
2005                 type_t             *element_type = arr_type->element_type;
2006
2007                 type = make_pointer_type(element_type, type->base.qualifiers);
2008
2009                 declaration->type = type;
2010         }
2011
2012         if(is_type_incomplete(type)) {
2013                 parser_print_error_prefix();
2014                 fprintf(stderr, "incomplete type (");
2015                 print_type_quoted(orig_type);
2016                 fprintf(stderr, ") not allowed for parameter '%s'\n",
2017                         declaration->symbol->string);
2018         }
2019 }
2020
2021 static declaration_t *parse_parameter(void)
2022 {
2023         declaration_specifiers_t specifiers;
2024         memset(&specifiers, 0, sizeof(specifiers));
2025
2026         parse_declaration_specifiers(&specifiers);
2027
2028         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
2029
2030         semantic_parameter(declaration);
2031
2032         return declaration;
2033 }
2034
2035 static declaration_t *parse_parameters(function_type_t *type)
2036 {
2037         if(token.type == T_IDENTIFIER) {
2038                 symbol_t *symbol = token.v.symbol;
2039                 if(!is_typedef_symbol(symbol)) {
2040                         type->kr_style_parameters = true;
2041                         return parse_identifier_list();
2042                 }
2043         }
2044
2045         if(token.type == ')') {
2046                 type->unspecified_parameters = 1;
2047                 return NULL;
2048         }
2049         if(token.type == T_void && look_ahead(1)->type == ')') {
2050                 next_token();
2051                 return NULL;
2052         }
2053
2054         declaration_t        *declarations = NULL;
2055         declaration_t        *declaration;
2056         declaration_t        *last_declaration = NULL;
2057         function_parameter_t *parameter;
2058         function_parameter_t *last_parameter = NULL;
2059
2060         while(true) {
2061                 switch(token.type) {
2062                 case T_DOTDOTDOT:
2063                         next_token();
2064                         type->variadic = 1;
2065                         return declarations;
2066
2067                 case T_IDENTIFIER:
2068                 case T___extension__:
2069                 DECLARATION_START
2070                         declaration = parse_parameter();
2071
2072                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
2073                         memset(parameter, 0, sizeof(parameter[0]));
2074                         parameter->type = declaration->type;
2075
2076                         if(last_parameter != NULL) {
2077                                 last_declaration->next = declaration;
2078                                 last_parameter->next   = parameter;
2079                         } else {
2080                                 type->parameters = parameter;
2081                                 declarations     = declaration;
2082                         }
2083                         last_parameter   = parameter;
2084                         last_declaration = declaration;
2085                         break;
2086
2087                 default:
2088                         return declarations;
2089                 }
2090                 if(token.type != ',')
2091                         return declarations;
2092                 next_token();
2093         }
2094 }
2095
2096 typedef enum {
2097         CONSTRUCT_INVALID,
2098         CONSTRUCT_POINTER,
2099         CONSTRUCT_FUNCTION,
2100         CONSTRUCT_ARRAY
2101 } construct_type_type_t;
2102
2103 typedef struct construct_type_t construct_type_t;
2104 struct construct_type_t {
2105         construct_type_type_t  type;
2106         construct_type_t      *next;
2107 };
2108
2109 typedef struct parsed_pointer_t parsed_pointer_t;
2110 struct parsed_pointer_t {
2111         construct_type_t  construct_type;
2112         type_qualifiers_t type_qualifiers;
2113 };
2114
2115 typedef struct construct_function_type_t construct_function_type_t;
2116 struct construct_function_type_t {
2117         construct_type_t  construct_type;
2118         type_t           *function_type;
2119 };
2120
2121 typedef struct parsed_array_t parsed_array_t;
2122 struct parsed_array_t {
2123         construct_type_t  construct_type;
2124         type_qualifiers_t type_qualifiers;
2125         bool              is_static;
2126         bool              is_variable;
2127         expression_t     *size;
2128 };
2129
2130 typedef struct construct_base_type_t construct_base_type_t;
2131 struct construct_base_type_t {
2132         construct_type_t  construct_type;
2133         type_t           *type;
2134 };
2135
2136 static construct_type_t *parse_pointer_declarator(void)
2137 {
2138         eat('*');
2139
2140         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
2141         memset(pointer, 0, sizeof(pointer[0]));
2142         pointer->construct_type.type = CONSTRUCT_POINTER;
2143         pointer->type_qualifiers     = parse_type_qualifiers();
2144
2145         return (construct_type_t*) pointer;
2146 }
2147
2148 static construct_type_t *parse_array_declarator(void)
2149 {
2150         eat('[');
2151
2152         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
2153         memset(array, 0, sizeof(array[0]));
2154         array->construct_type.type = CONSTRUCT_ARRAY;
2155
2156         if(token.type == T_static) {
2157                 array->is_static = true;
2158                 next_token();
2159         }
2160
2161         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
2162         if(type_qualifiers != 0) {
2163                 if(token.type == T_static) {
2164                         array->is_static = true;
2165                         next_token();
2166                 }
2167         }
2168         array->type_qualifiers = type_qualifiers;
2169
2170         if(token.type == '*' && look_ahead(1)->type == ']') {
2171                 array->is_variable = true;
2172                 next_token();
2173         } else if(token.type != ']') {
2174                 array->size = parse_assignment_expression();
2175         }
2176
2177         expect(']');
2178
2179         return (construct_type_t*) array;
2180 }
2181
2182 static construct_type_t *parse_function_declarator(declaration_t *declaration)
2183 {
2184         eat('(');
2185
2186         type_t *type = allocate_type_zero(TYPE_FUNCTION);
2187
2188         declaration_t *parameters = parse_parameters(&type->function);
2189         if(declaration != NULL) {
2190                 declaration->context.declarations = parameters;
2191         }
2192
2193         construct_function_type_t *construct_function_type =
2194                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
2195         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
2196         construct_function_type->construct_type.type = CONSTRUCT_FUNCTION;
2197         construct_function_type->function_type       = type;
2198
2199         expect(')');
2200
2201         return (construct_type_t*) construct_function_type;
2202 }
2203
2204 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
2205                 bool may_be_abstract)
2206 {
2207         /* construct a single linked list of construct_type_t's which describe
2208          * how to construct the final declarator type */
2209         construct_type_t *first = NULL;
2210         construct_type_t *last  = NULL;
2211
2212         /* pointers */
2213         while(token.type == '*') {
2214                 construct_type_t *type = parse_pointer_declarator();
2215
2216                 if(last == NULL) {
2217                         first = type;
2218                         last  = type;
2219                 } else {
2220                         last->next = type;
2221                         last       = type;
2222                 }
2223         }
2224
2225         /* TODO: find out if this is correct */
2226         parse_attributes();
2227
2228         construct_type_t *inner_types = NULL;
2229
2230         switch(token.type) {
2231         case T_IDENTIFIER:
2232                 if(declaration == NULL) {
2233                         parse_error("no identifier expected in typename");
2234                 } else {
2235                         declaration->symbol          = token.v.symbol;
2236                         declaration->source_position = token.source_position;
2237                 }
2238                 next_token();
2239                 break;
2240         case '(':
2241                 next_token();
2242                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
2243                 expect(')');
2244                 break;
2245         default:
2246                 if(may_be_abstract)
2247                         break;
2248                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
2249                 /* avoid a loop in the outermost scope, because eat_statement doesn't
2250                  * eat '}' */
2251                 if(token.type == '}' && current_function == NULL) {
2252                         next_token();
2253                 } else {
2254                         eat_statement();
2255                 }
2256                 return NULL;
2257         }
2258
2259         construct_type_t *p = last;
2260
2261         while(true) {
2262                 construct_type_t *type;
2263                 switch(token.type) {
2264                 case '(':
2265                         type = parse_function_declarator(declaration);
2266                         break;
2267                 case '[':
2268                         type = parse_array_declarator();
2269                         break;
2270                 default:
2271                         goto declarator_finished;
2272                 }
2273
2274                 /* insert in the middle of the list (behind p) */
2275                 if(p != NULL) {
2276                         type->next = p->next;
2277                         p->next    = type;
2278                 } else {
2279                         type->next = first;
2280                         first      = type;
2281                 }
2282                 if(last == p) {
2283                         last = type;
2284                 }
2285         }
2286
2287 declarator_finished:
2288         parse_attributes();
2289
2290         /* append inner_types at the end of the list, we don't to set last anymore
2291          * as it's not needed anymore */
2292         if(last == NULL) {
2293                 assert(first == NULL);
2294                 first = inner_types;
2295         } else {
2296                 last->next = inner_types;
2297         }
2298
2299         return first;
2300 }
2301
2302 static type_t *construct_declarator_type(construct_type_t *construct_list,
2303                                          type_t *type)
2304 {
2305         construct_type_t *iter = construct_list;
2306         for( ; iter != NULL; iter = iter->next) {
2307                 switch(iter->type) {
2308                 case CONSTRUCT_INVALID:
2309                         panic("invalid type construction found");
2310                 case CONSTRUCT_FUNCTION: {
2311                         construct_function_type_t *construct_function_type
2312                                 = (construct_function_type_t*) iter;
2313
2314                         type_t *function_type = construct_function_type->function_type;
2315
2316                         function_type->function.return_type = type;
2317
2318                         type = function_type;
2319                         break;
2320                 }
2321
2322                 case CONSTRUCT_POINTER: {
2323                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
2324                         type_t           *pointer_type   = allocate_type_zero(TYPE_POINTER);
2325                         pointer_type->pointer.points_to  = type;
2326                         pointer_type->base.qualifiers    = parsed_pointer->type_qualifiers;
2327
2328                         type = pointer_type;
2329                         break;
2330                 }
2331
2332                 case CONSTRUCT_ARRAY: {
2333                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
2334                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
2335
2336                         array_type->base.qualifiers    = parsed_array->type_qualifiers;
2337                         array_type->array.element_type = type;
2338                         array_type->array.is_static    = parsed_array->is_static;
2339                         array_type->array.is_variable  = parsed_array->is_variable;
2340                         array_type->array.size         = parsed_array->size;
2341
2342                         type = array_type;
2343                         break;
2344                 }
2345                 }
2346
2347                 type_t *hashed_type = typehash_insert(type);
2348                 if(hashed_type != type) {
2349                         /* the function type was constructed earlier freeing it here will
2350                          * destroy other types... */
2351                         if(iter->type != CONSTRUCT_FUNCTION) {
2352                                 free_type(type);
2353                         }
2354                         type = hashed_type;
2355                 }
2356         }
2357
2358         return type;
2359 }
2360
2361 static declaration_t *parse_declarator(
2362                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
2363 {
2364         type_t        *type         = specifiers->type;
2365         declaration_t *declaration  = allocate_ast_zero(sizeof(declaration[0]));
2366         declaration->storage_class  = specifiers->storage_class;
2367         declaration->decl_modifiers = specifiers->decl_modifiers;
2368         declaration->is_inline      = specifiers->is_inline;
2369
2370         construct_type_t *construct_type
2371                 = parse_inner_declarator(declaration, may_be_abstract);
2372         declaration->type = construct_declarator_type(construct_type, type);
2373
2374         if(construct_type != NULL) {
2375                 obstack_free(&temp_obst, construct_type);
2376         }
2377
2378         return declaration;
2379 }
2380
2381 static type_t *parse_abstract_declarator(type_t *base_type)
2382 {
2383         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2384
2385         type_t *result = construct_declarator_type(construct_type, base_type);
2386         if(construct_type != NULL) {
2387                 obstack_free(&temp_obst, construct_type);
2388         }
2389
2390         return result;
2391 }
2392
2393 static declaration_t *record_declaration(declaration_t *declaration)
2394 {
2395         assert(declaration->parent_context == NULL);
2396         assert(context != NULL);
2397
2398         symbol_t *symbol = declaration->symbol;
2399         if(symbol != NULL) {
2400                 declaration_t *alias = environment_push(declaration);
2401                 if(alias != declaration)
2402                         return alias;
2403         } else {
2404                 declaration->parent_context = context;
2405         }
2406
2407         if(last_declaration != NULL) {
2408                 last_declaration->next = declaration;
2409         } else {
2410                 context->declarations = declaration;
2411         }
2412         last_declaration = declaration;
2413
2414         return declaration;
2415 }
2416
2417 static void parser_error_multiple_definition(declaration_t *declaration,
2418                 const source_position_t source_position)
2419 {
2420         parser_print_error_prefix_pos(source_position);
2421         fprintf(stderr, "multiple definition of symbol '%s'\n",
2422                 declaration->symbol->string);
2423         parser_print_error_prefix_pos(declaration->source_position);
2424         fprintf(stderr, "this is the location of the previous definition.\n");
2425 }
2426
2427 static bool is_declaration_specifier(const token_t *token,
2428                                      bool only_type_specifiers)
2429 {
2430         switch(token->type) {
2431                 TYPE_SPECIFIERS
2432                         return true;
2433                 case T_IDENTIFIER:
2434                         return is_typedef_symbol(token->v.symbol);
2435
2436                 case T___extension__:
2437                 STORAGE_CLASSES
2438                 TYPE_QUALIFIERS
2439                         return !only_type_specifiers;
2440
2441                 default:
2442                         return false;
2443         }
2444 }
2445
2446 static void parse_init_declarator_rest(declaration_t *declaration)
2447 {
2448         eat('=');
2449
2450         type_t *orig_type = declaration->type;
2451         type_t *type      = NULL;
2452         if(orig_type != NULL)
2453                 type = skip_typeref(orig_type);
2454
2455         if(declaration->init.initializer != NULL) {
2456                 parser_error_multiple_definition(declaration, token.source_position);
2457         }
2458
2459         initializer_t *initializer = parse_initializer(type);
2460
2461         /* § 6.7.5 (22)  array intializers for arrays with unknown size determine
2462          * the array type size */
2463         if(type != NULL && is_type_array(type) && initializer != NULL) {
2464                 array_type_t *array_type = &type->array;
2465
2466                 if(array_type->size == NULL) {
2467                         expression_t *cnst = allocate_expression_zero(EXPR_CONST);
2468
2469                         cnst->base.datatype = type_size_t;
2470
2471                         switch (initializer->type) {
2472                                 case INITIALIZER_LIST: {
2473                                         initializer_list_t *const list = &initializer->list;
2474                                         cnst->conste.v.int_value = list->len;
2475                                         break;
2476                                 }
2477
2478                                 case INITIALIZER_STRING: {
2479                                         initializer_string_t *const string = &initializer->string;
2480                                         cnst->conste.v.int_value = strlen(string->string) + 1;
2481                                         break;
2482                                 }
2483
2484                                 case INITIALIZER_WIDE_STRING: {
2485                                         initializer_wide_string_t *const string = &initializer->wide_string;
2486                                         cnst->conste.v.int_value = string->string.size;
2487                                         break;
2488                                 }
2489
2490                                 default:
2491                                         panic("invalid initializer type");
2492                         }
2493
2494                         array_type->size = cnst;
2495                 }
2496         }
2497
2498         if(type != NULL && is_type_function(type)) {
2499                 parser_print_error_prefix_pos(declaration->source_position);
2500                 fprintf(stderr, "initializers not allowed for function types at "
2501                                 "declator '%s' (type ", declaration->symbol->string);
2502                 print_type_quoted(orig_type);
2503                 fprintf(stderr, ")\n");
2504         } else {
2505                 declaration->init.initializer = initializer;
2506         }
2507 }
2508
2509 /* parse rest of a declaration without any declarator */
2510 static void parse_anonymous_declaration_rest(
2511                 const declaration_specifiers_t *specifiers,
2512                 parsed_declaration_func finished_declaration)
2513 {
2514         eat(';');
2515
2516         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2517
2518         declaration->type            = specifiers->type;
2519         declaration->storage_class   = specifiers->storage_class;
2520         declaration->source_position = specifiers->source_position;
2521
2522         if (declaration->storage_class != STORAGE_CLASS_NONE) {
2523                 parse_warning_pos(declaration->source_position,
2524                                 "useless storage class in empty declaration");
2525         }
2526
2527         type_t *type = declaration->type;
2528         switch (type->type) {
2529                 case TYPE_COMPOUND_STRUCT:
2530                 case TYPE_COMPOUND_UNION: {
2531                         const compound_type_t *compound_type = &type->compound;
2532                         if (compound_type->declaration->symbol == NULL) {
2533                                 parse_warning_pos(declaration->source_position,
2534                                                 "unnamed struct/union that defines no instances");
2535                         }
2536                         break;
2537                 }
2538
2539                 case TYPE_ENUM:
2540                         break;
2541
2542                 default:
2543                         parse_warning_pos(declaration->source_position,
2544                                           "empty declaration");
2545                         break;
2546         }
2547
2548         finished_declaration(declaration);
2549 }
2550
2551 static void parse_declaration_rest(declaration_t *ndeclaration,
2552                 const declaration_specifiers_t *specifiers,
2553                 parsed_declaration_func finished_declaration)
2554 {
2555         while(true) {
2556                 declaration_t *declaration = finished_declaration(ndeclaration);
2557
2558                 type_t *orig_type = declaration->type;
2559                 type_t *type      = skip_typeref(orig_type);
2560
2561                 if(type->type != TYPE_FUNCTION && declaration->is_inline) {
2562                         parser_print_warning_prefix_pos(declaration->source_position);
2563                         fprintf(stderr, "variable '%s' declared 'inline'\n",
2564                                         declaration->symbol->string);
2565                 }
2566
2567                 if(token.type == '=') {
2568                         parse_init_declarator_rest(declaration);
2569                 }
2570
2571                 if(token.type != ',')
2572                         break;
2573                 eat(',');
2574
2575                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
2576         }
2577         expect_void(';');
2578 }
2579
2580 static declaration_t *finished_kr_declaration(declaration_t *declaration)
2581 {
2582         /* TODO: check that it was actually a parameter that gets a type */
2583
2584         /* we should have a declaration for the parameter in the current
2585          * scope */
2586         return record_declaration(declaration);
2587 }
2588
2589 static void parse_declaration(parsed_declaration_func finished_declaration)
2590 {
2591         declaration_specifiers_t specifiers;
2592         memset(&specifiers, 0, sizeof(specifiers));
2593         parse_declaration_specifiers(&specifiers);
2594
2595         if(token.type == ';') {
2596                 parse_anonymous_declaration_rest(&specifiers, finished_declaration);
2597         } else {
2598                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2599                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
2600         }
2601 }
2602
2603 static void parse_kr_declaration_list(declaration_t *declaration)
2604 {
2605         type_t *type = skip_typeref(declaration->type);
2606         if(!is_type_function(type))
2607                 return;
2608
2609         if(!type->function.kr_style_parameters)
2610                 return;
2611
2612         /* push function parameters */
2613         int         top          = environment_top();
2614         context_t  *last_context = context;
2615         set_context(&declaration->context);
2616
2617         declaration_t *parameter = declaration->context.declarations;
2618         for( ; parameter != NULL; parameter = parameter->next) {
2619                 environment_push(parameter);
2620         }
2621
2622         /* parse declaration list */
2623         while(is_declaration_specifier(&token, false)) {
2624                 parse_declaration(finished_kr_declaration);
2625         }
2626
2627         /* pop function parameters */
2628         assert(context == &declaration->context);
2629         set_context(last_context);
2630         environment_pop_to(top);
2631
2632         /* update function type */
2633         type_t *new_type = duplicate_type(type);
2634         new_type->function.kr_style_parameters = false;
2635
2636         function_parameter_t *parameters     = NULL;
2637         function_parameter_t *last_parameter = NULL;
2638
2639         declaration_t *parameter_declaration = declaration->context.declarations;
2640         for( ; parameter_declaration != NULL;
2641                         parameter_declaration = parameter_declaration->next) {
2642                 type_t *parameter_type = parameter_declaration->type;
2643                 if(parameter_type == NULL) {
2644 #ifdef STRICT_C99
2645                         parser_print_error_prefix();
2646                         fprintf(stderr, "no type specified for function parameter '%s'\n",
2647                                 parameter_declaration->symbol->string);
2648 #else
2649                         parser_print_warning_prefix();
2650                         fprintf(stderr, "no type specified for function parameter '%s', "
2651                                 "using int\n", parameter_declaration->symbol->string);
2652                         parameter_type              = type_int;
2653                         parameter_declaration->type = parameter_type;
2654 #endif
2655                 }
2656
2657                 semantic_parameter(parameter_declaration);
2658                 parameter_type = parameter_declaration->type;
2659
2660                 function_parameter_t *function_parameter
2661                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
2662                 memset(function_parameter, 0, sizeof(function_parameter[0]));
2663
2664                 function_parameter->type = parameter_type;
2665                 if(last_parameter != NULL) {
2666                         last_parameter->next = function_parameter;
2667                 } else {
2668                         parameters = function_parameter;
2669                 }
2670                 last_parameter = function_parameter;
2671         }
2672         new_type->function.parameters = parameters;
2673
2674         type = typehash_insert(new_type);
2675         if(type != new_type) {
2676                 obstack_free(type_obst, new_type);
2677         }
2678
2679         declaration->type = type;
2680 }
2681
2682 static void parse_external_declaration(void)
2683 {
2684         /* function-definitions and declarations both start with declaration
2685          * specifiers */
2686         declaration_specifiers_t specifiers;
2687         memset(&specifiers, 0, sizeof(specifiers));
2688         parse_declaration_specifiers(&specifiers);
2689
2690         /* must be a declaration */
2691         if(token.type == ';') {
2692                 parse_anonymous_declaration_rest(&specifiers, record_declaration);
2693                 return;
2694         }
2695
2696         /* declarator is common to both function-definitions and declarations */
2697         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2698
2699         /* must be a declaration */
2700         if(token.type == ',' || token.type == '=' || token.type == ';') {
2701                 parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
2702                 return;
2703         }
2704
2705         /* must be a function definition */
2706         parse_kr_declaration_list(ndeclaration);
2707
2708         if(token.type != '{') {
2709                 parse_error_expected("while parsing function definition", '{', 0);
2710                 eat_statement();
2711                 return;
2712         }
2713
2714         type_t *type = ndeclaration->type;
2715         if(type == NULL) {
2716                 eat_block();
2717                 return;
2718         }
2719
2720         /* note that we don't skip typerefs: the standard doesn't allow them here
2721          * (so we can't use is_type_function here) */
2722         if(type->type != TYPE_FUNCTION) {
2723                 parser_print_error_prefix();
2724                 fprintf(stderr, "declarator '");
2725                 print_type_ext(type, ndeclaration->symbol, NULL);
2726                 fprintf(stderr, "' has a body but is not a function type.\n");
2727                 eat_block();
2728                 return;
2729         }
2730
2731         /* § 6.7.5.3 (14) a function definition with () means no
2732          * parameters (and not unspecified parameters) */
2733         if(type->function.unspecified_parameters) {
2734                 type_t *duplicate = duplicate_type(type);
2735                 duplicate->function.unspecified_parameters = false;
2736
2737                 type = typehash_insert(duplicate);
2738                 if(type != duplicate) {
2739                         obstack_free(type_obst, duplicate);
2740                 }
2741                 ndeclaration->type = type;
2742         }
2743
2744         declaration_t *declaration = record_declaration(ndeclaration);
2745         if(ndeclaration != declaration) {
2746                 memcpy(&declaration->context, &ndeclaration->context,
2747                                 sizeof(declaration->context));
2748         }
2749         type = skip_typeref(declaration->type);
2750
2751         /* push function parameters and switch context */
2752         int         top          = environment_top();
2753         context_t  *last_context = context;
2754         set_context(&declaration->context);
2755
2756         declaration_t *parameter = declaration->context.declarations;
2757         for( ; parameter != NULL; parameter = parameter->next) {
2758                 environment_push(parameter);
2759         }
2760
2761         if(declaration->init.statement != NULL) {
2762                 parser_error_multiple_definition(declaration, token.source_position);
2763                 eat_block();
2764                 goto end_of_parse_external_declaration;
2765         } else {
2766                 /* parse function body */
2767                 int            label_stack_top      = label_top();
2768                 declaration_t *old_current_function = current_function;
2769                 current_function                    = declaration;
2770
2771                 declaration->init.statement = parse_compound_statement();
2772
2773                 assert(current_function == declaration);
2774                 current_function = old_current_function;
2775                 label_pop_to(label_stack_top);
2776         }
2777
2778 end_of_parse_external_declaration:
2779         assert(context == &declaration->context);
2780         set_context(last_context);
2781         environment_pop_to(top);
2782 }
2783
2784 static void parse_struct_declarators(const declaration_specifiers_t *specifiers)
2785 {
2786         while(1) {
2787                 if(token.type == ':') {
2788                         next_token();
2789                         parse_constant_expression();
2790                         /* TODO (bitfields) */
2791                 } else {
2792                         declaration_t *declaration = parse_declarator(specifiers, /*may_be_abstract=*/true);
2793
2794                         /* TODO: check constraints for struct declarations */
2795                         /* TODO: check for doubled fields */
2796                         record_declaration(declaration);
2797
2798                         if(token.type == ':') {
2799                                 next_token();
2800                                 parse_constant_expression();
2801                                 /* TODO (bitfields) */
2802                         }
2803                 }
2804
2805                 if(token.type != ',')
2806                         break;
2807                 next_token();
2808         }
2809         expect_void(';');
2810 }
2811
2812 static void parse_compound_type_entries(void)
2813 {
2814         eat('{');
2815
2816         while(token.type != '}' && token.type != T_EOF) {
2817                 declaration_specifiers_t specifiers;
2818                 memset(&specifiers, 0, sizeof(specifiers));
2819                 parse_declaration_specifiers(&specifiers);
2820
2821                 parse_struct_declarators(&specifiers);
2822         }
2823         if(token.type == T_EOF) {
2824                 parse_error("EOF while parsing struct");
2825         }
2826         next_token();
2827 }
2828
2829 static type_t *parse_typename(void)
2830 {
2831         declaration_specifiers_t specifiers;
2832         memset(&specifiers, 0, sizeof(specifiers));
2833         parse_declaration_specifiers(&specifiers);
2834         if(specifiers.storage_class != STORAGE_CLASS_NONE) {
2835                 /* TODO: improve error message, user does probably not know what a
2836                  * storage class is...
2837                  */
2838                 parse_error("typename may not have a storage class");
2839         }
2840
2841         type_t *result = parse_abstract_declarator(specifiers.type);
2842
2843         return result;
2844 }
2845
2846
2847
2848
2849 typedef expression_t* (*parse_expression_function) (unsigned precedence);
2850 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
2851                                                           expression_t *left);
2852
2853 typedef struct expression_parser_function_t expression_parser_function_t;
2854 struct expression_parser_function_t {
2855         unsigned                         precedence;
2856         parse_expression_function        parser;
2857         unsigned                         infix_precedence;
2858         parse_expression_infix_function  infix_parser;
2859 };
2860
2861 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
2862
2863 static expression_t *create_invalid_expression(void)
2864 {
2865         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
2866         expression->base.source_position = token.source_position;
2867         return expression;
2868 }
2869
2870 static expression_t *expected_expression_error(void)
2871 {
2872         parser_print_error_prefix();
2873         fprintf(stderr, "expected expression, got token ");
2874         print_token(stderr, &token);
2875         fprintf(stderr, "\n");
2876
2877         next_token();
2878
2879         return create_invalid_expression();
2880 }
2881
2882 static expression_t *parse_string_const(void)
2883 {
2884         expression_t *cnst  = allocate_expression_zero(EXPR_STRING_LITERAL);
2885         cnst->base.datatype = type_string;
2886         cnst->string.value  = parse_string_literals();
2887
2888         return cnst;
2889 }
2890
2891 static expression_t *parse_wide_string_const(void)
2892 {
2893         expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
2894         cnst->base.datatype      = type_wchar_t_ptr;
2895         cnst->wide_string.value  = token.v.wide_string; /* TODO concatenate */
2896         next_token();
2897         return cnst;
2898 }
2899
2900 static expression_t *parse_int_const(void)
2901 {
2902         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2903         cnst->base.datatype      = token.datatype;
2904         cnst->conste.v.int_value = token.v.intvalue;
2905
2906         next_token();
2907
2908         return cnst;
2909 }
2910
2911 static expression_t *parse_float_const(void)
2912 {
2913         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
2914         cnst->base.datatype        = token.datatype;
2915         cnst->conste.v.float_value = token.v.floatvalue;
2916
2917         next_token();
2918
2919         return cnst;
2920 }
2921
2922 static declaration_t *create_implicit_function(symbol_t *symbol,
2923                 const source_position_t source_position)
2924 {
2925         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
2926         ntype->function.return_type            = type_int;
2927         ntype->function.unspecified_parameters = true;
2928
2929         type_t *type = typehash_insert(ntype);
2930         if(type != ntype) {
2931                 free_type(ntype);
2932         }
2933
2934         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2935
2936         declaration->storage_class   = STORAGE_CLASS_EXTERN;
2937         declaration->type            = type;
2938         declaration->symbol          = symbol;
2939         declaration->source_position = source_position;
2940
2941         /* prepend the implicit definition to the global context
2942          * this is safe since the symbol wasn't declared as anything else yet
2943          */
2944         assert(symbol->declaration == NULL);
2945
2946         context_t *last_context = context;
2947         context = global_context;
2948
2949         environment_push(declaration);
2950         declaration->next     = context->declarations;
2951         context->declarations = declaration;
2952
2953         context = last_context;
2954
2955         return declaration;
2956 }
2957
2958 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
2959 {
2960         function_parameter_t *parameter
2961                 = obstack_alloc(type_obst, sizeof(parameter[0]));
2962         memset(parameter, 0, sizeof(parameter[0]));
2963         parameter->type = argument_type;
2964
2965         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
2966         type->function.return_type = return_type;
2967         type->function.parameters  = parameter;
2968
2969         type_t *result = typehash_insert(type);
2970         if(result != type) {
2971                 free_type(type);
2972         }
2973
2974         return result;
2975 }
2976
2977 static type_t *get_builtin_symbol_type(symbol_t *symbol)
2978 {
2979         switch(symbol->ID) {
2980         case T___builtin_alloca:
2981                 return make_function_1_type(type_void_ptr, type_size_t);
2982         case T___builtin_nan:
2983                 return make_function_1_type(type_double, type_string);
2984         case T___builtin_nanf:
2985                 return make_function_1_type(type_float, type_string);
2986         case T___builtin_nand:
2987                 return make_function_1_type(type_long_double, type_string);
2988         case T___builtin_va_end:
2989                 return make_function_1_type(type_void, type_valist);
2990         default:
2991                 panic("not implemented builtin symbol found");
2992         }
2993 }
2994
2995 /**
2996  * performs automatic type cast as described in § 6.3.2.1
2997  */
2998 static type_t *automatic_type_conversion(type_t *orig_type)
2999 {
3000         if(orig_type == NULL)
3001                 return NULL;
3002
3003         type_t *type = skip_typeref(orig_type);
3004         if(is_type_array(type)) {
3005                 array_type_t *array_type   = &type->array;
3006                 type_t       *element_type = array_type->element_type;
3007                 unsigned      qualifiers   = array_type->type.qualifiers;
3008
3009                 return make_pointer_type(element_type, qualifiers);
3010         }
3011
3012         if(is_type_function(type)) {
3013                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3014         }
3015
3016         return orig_type;
3017 }
3018
3019 /**
3020  * reverts the automatic casts of array to pointer types and function
3021  * to function-pointer types as defined § 6.3.2.1
3022  */
3023 type_t *revert_automatic_type_conversion(const expression_t *expression)
3024 {
3025         if(expression->base.datatype == NULL)
3026                 return NULL;
3027
3028         switch(expression->type) {
3029         case EXPR_REFERENCE: {
3030                 const reference_expression_t *ref = &expression->reference;
3031                 return ref->declaration->type;
3032         }
3033         case EXPR_SELECT: {
3034                 const select_expression_t *select = &expression->select;
3035                 return select->compound_entry->type;
3036         }
3037         case EXPR_UNARY_DEREFERENCE: {
3038                 expression_t   *value        = expression->unary.value;
3039                 type_t         *type         = skip_typeref(value->base.datatype);
3040                 pointer_type_t *pointer_type = &type->pointer;
3041
3042                 return pointer_type->points_to;
3043         }
3044         case EXPR_BUILTIN_SYMBOL: {
3045                 const builtin_symbol_expression_t *builtin
3046                         = &expression->builtin_symbol;
3047                 return get_builtin_symbol_type(builtin->symbol);
3048         }
3049         case EXPR_ARRAY_ACCESS: {
3050                 const array_access_expression_t *array_access
3051                         = &expression->array_access;
3052                 const expression_t *array_ref = array_access->array_ref;
3053                 type_t *type_left  = skip_typeref(array_ref->base.datatype);
3054                 assert(is_type_pointer(type_left));
3055                 pointer_type_t *pointer_type = &type_left->pointer;
3056                 return pointer_type->points_to;
3057         }
3058
3059         default:
3060                 break;
3061         }
3062
3063         return expression->base.datatype;
3064 }
3065
3066 static expression_t *parse_reference(void)
3067 {
3068         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
3069
3070         reference_expression_t *ref = &expression->reference;
3071         ref->symbol = token.v.symbol;
3072
3073         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
3074
3075         source_position_t source_position = token.source_position;
3076         next_token();
3077
3078         if(declaration == NULL) {
3079 #ifndef STRICT_C99
3080                 /* an implicitly defined function */
3081                 if(token.type == '(') {
3082                         parser_print_prefix_pos(token.source_position);
3083                         fprintf(stderr, "warning: implicit declaration of function '%s'\n",
3084                                 ref->symbol->string);
3085
3086                         declaration = create_implicit_function(ref->symbol,
3087                                                                source_position);
3088                 } else
3089 #endif
3090                 {
3091                         parser_print_error_prefix();
3092                         fprintf(stderr, "unknown symbol '%s' found.\n", ref->symbol->string);
3093                         return expression;
3094                 }
3095         }
3096
3097         type_t *type = declaration->type;
3098         /* we always do the auto-type conversions; the & and sizeof parser contains
3099          * code to revert this! */
3100         type = automatic_type_conversion(type);
3101
3102         ref->declaration         = declaration;
3103         ref->expression.datatype = type;
3104
3105         return expression;
3106 }
3107
3108 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
3109 {
3110         (void) expression;
3111         (void) dest_type;
3112         /* TODO check if explicit cast is allowed and issue warnings/errors */
3113 }
3114
3115 static expression_t *parse_cast(void)
3116 {
3117         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
3118
3119         cast->base.source_position = token.source_position;
3120
3121         type_t *type  = parse_typename();
3122
3123         expect(')');
3124         expression_t *value = parse_sub_expression(20);
3125
3126         check_cast_allowed(value, type);
3127
3128         cast->base.datatype = type;
3129         cast->unary.value   = value;
3130
3131         return cast;
3132 }
3133
3134 static expression_t *parse_statement_expression(void)
3135 {
3136         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
3137
3138         statement_t *statement          = parse_compound_statement();
3139         expression->statement.statement = statement;
3140         if(statement == NULL) {
3141                 expect(')');
3142                 return NULL;
3143         }
3144
3145         assert(statement->type == STATEMENT_COMPOUND);
3146         compound_statement_t *compound_statement = &statement->compound;
3147
3148         /* find last statement and use it's type */
3149         const statement_t *last_statement = NULL;
3150         const statement_t *iter           = compound_statement->statements;
3151         for( ; iter != NULL; iter = iter->base.next) {
3152                 last_statement = iter;
3153         }
3154
3155         if(last_statement->type == STATEMENT_EXPRESSION) {
3156                 const expression_statement_t *expression_statement
3157                         = &last_statement->expression;
3158                 expression->base.datatype
3159                         = expression_statement->expression->base.datatype;
3160         } else {
3161                 expression->base.datatype = type_void;
3162         }
3163
3164         expect(')');
3165
3166         return expression;
3167 }
3168
3169 static expression_t *parse_brace_expression(void)
3170 {
3171         eat('(');
3172
3173         switch(token.type) {
3174         case '{':
3175                 /* gcc extension: a stement expression */
3176                 return parse_statement_expression();
3177
3178         TYPE_QUALIFIERS
3179         TYPE_SPECIFIERS
3180                 return parse_cast();
3181         case T_IDENTIFIER:
3182                 if(is_typedef_symbol(token.v.symbol)) {
3183                         return parse_cast();
3184                 }
3185         }
3186
3187         expression_t *result = parse_expression();
3188         expect(')');
3189
3190         return result;
3191 }
3192
3193 static expression_t *parse_function_keyword(void)
3194 {
3195         next_token();
3196         /* TODO */
3197
3198         if (current_function == NULL) {
3199                 parse_error("'__func__' used outside of a function");
3200         }
3201
3202         string_literal_expression_t *expression
3203                 = allocate_ast_zero(sizeof(expression[0]));
3204
3205         expression->expression.type     = EXPR_FUNCTION;
3206         expression->expression.datatype = type_string;
3207         expression->value               = current_function->symbol->string;
3208
3209         return (expression_t*) expression;
3210 }
3211
3212 static expression_t *parse_pretty_function_keyword(void)
3213 {
3214         eat(T___PRETTY_FUNCTION__);
3215         /* TODO */
3216
3217         if (current_function == NULL) {
3218                 parse_error("'__PRETTY_FUNCTION__' used outside of a function");
3219         }
3220
3221         string_literal_expression_t *expression
3222                 = allocate_ast_zero(sizeof(expression[0]));
3223
3224         expression->expression.type     = EXPR_PRETTY_FUNCTION;
3225         expression->expression.datatype = type_string;
3226         expression->value               = current_function->symbol->string;
3227
3228         return (expression_t*) expression;
3229 }
3230
3231 static designator_t *parse_designator(void)
3232 {
3233         designator_t *result = allocate_ast_zero(sizeof(result[0]));
3234
3235         if(token.type != T_IDENTIFIER) {
3236                 parse_error_expected("while parsing member designator",
3237                                      T_IDENTIFIER, 0);
3238                 eat_paren();
3239                 return NULL;
3240         }
3241         result->symbol = token.v.symbol;
3242         next_token();
3243
3244         designator_t *last_designator = result;
3245         while(true) {
3246                 if(token.type == '.') {
3247                         next_token();
3248                         if(token.type != T_IDENTIFIER) {
3249                                 parse_error_expected("while parsing member designator",
3250                                                      T_IDENTIFIER, 0);
3251                                 eat_paren();
3252                                 return NULL;
3253                         }
3254                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3255                         designator->symbol       = token.v.symbol;
3256                         next_token();
3257
3258                         last_designator->next = designator;
3259                         last_designator       = designator;
3260                         continue;
3261                 }
3262                 if(token.type == '[') {
3263                         next_token();
3264                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3265                         designator->array_access = parse_expression();
3266                         if(designator->array_access == NULL) {
3267                                 eat_paren();
3268                                 return NULL;
3269                         }
3270                         expect(']');
3271
3272                         last_designator->next = designator;
3273                         last_designator       = designator;
3274                         continue;
3275                 }
3276                 break;
3277         }
3278
3279         return result;
3280 }
3281
3282 static expression_t *parse_offsetof(void)
3283 {
3284         eat(T___builtin_offsetof);
3285
3286         expression_t *expression  = allocate_expression_zero(EXPR_OFFSETOF);
3287         expression->base.datatype = type_size_t;
3288
3289         expect('(');
3290         expression->offsetofe.type = parse_typename();
3291         expect(',');
3292         expression->offsetofe.designator = parse_designator();
3293         expect(')');
3294
3295         return expression;
3296 }
3297
3298 static expression_t *parse_va_start(void)
3299 {
3300         eat(T___builtin_va_start);
3301
3302         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
3303
3304         expect('(');
3305         expression->va_starte.ap = parse_assignment_expression();
3306         expect(',');
3307         expression_t *const expr = parse_assignment_expression();
3308         if (expr->type == EXPR_REFERENCE) {
3309                 declaration_t *const decl = expr->reference.declaration;
3310                 if (decl->parent_context == &current_function->context &&
3311                     decl->next == NULL) {
3312                         expression->va_starte.parameter = decl;
3313                         expect(')');
3314                         return expression;
3315                 }
3316         }
3317         parser_print_error_prefix_pos(expr->base.source_position);
3318         fprintf(stderr, "second argument of 'va_start' must be last parameter "
3319                         "of the current function\n");
3320
3321         return create_invalid_expression();
3322 }
3323
3324 static expression_t *parse_va_arg(void)
3325 {
3326         eat(T___builtin_va_arg);
3327
3328         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
3329
3330         expect('(');
3331         expression->va_arge.ap = parse_assignment_expression();
3332         expect(',');
3333         expression->base.datatype = parse_typename();
3334         expect(')');
3335
3336         return expression;
3337 }
3338
3339 static expression_t *parse_builtin_symbol(void)
3340 {
3341         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
3342
3343         symbol_t *symbol = token.v.symbol;
3344
3345         expression->builtin_symbol.symbol = symbol;
3346         next_token();
3347
3348         type_t *type = get_builtin_symbol_type(symbol);
3349         type = automatic_type_conversion(type);
3350
3351         expression->base.datatype = type;
3352         return expression;
3353 }
3354
3355 static expression_t *parse_compare_builtin(void)
3356 {
3357         expression_t *expression;
3358
3359         switch(token.type) {
3360         case T___builtin_isgreater:
3361                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
3362                 break;
3363         case T___builtin_isgreaterequal:
3364                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
3365                 break;
3366         case T___builtin_isless:
3367                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
3368                 break;
3369         case T___builtin_islessequal:
3370                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
3371                 break;
3372         case T___builtin_islessgreater:
3373                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
3374                 break;
3375         case T___builtin_isunordered:
3376                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
3377                 break;
3378         default:
3379                 panic("invalid compare builtin found");
3380                 break;
3381         }
3382         next_token();
3383
3384         expect('(');
3385         expression->binary.left = parse_assignment_expression();
3386         expect(',');
3387         expression->binary.right = parse_assignment_expression();
3388         expect(')');
3389
3390         type_t *orig_type_left  = expression->binary.left->base.datatype;
3391         type_t *orig_type_right = expression->binary.right->base.datatype;
3392         if(orig_type_left == NULL || orig_type_right == NULL)
3393                 return expression;
3394
3395         type_t *type_left  = skip_typeref(orig_type_left);
3396         type_t *type_right = skip_typeref(orig_type_right);
3397         if(!is_type_floating(type_left) && !is_type_floating(type_right)) {
3398                 type_error_incompatible("invalid operands in comparison",
3399                                         token.source_position, type_left, type_right);
3400         } else {
3401                 semantic_comparison(&expression->binary);
3402         }
3403
3404         return expression;
3405 }
3406
3407 static expression_t *parse_primary_expression(void)
3408 {
3409         switch(token.type) {
3410         case T_INTEGER:
3411                 return parse_int_const();
3412         case T_FLOATINGPOINT:
3413                 return parse_float_const();
3414         case T_STRING_LITERAL: /* TODO merge */
3415                 return parse_string_const();
3416         case T_WIDE_STRING_LITERAL:
3417                 return parse_wide_string_const();
3418         case T_IDENTIFIER:
3419                 return parse_reference();
3420         case T___FUNCTION__:
3421         case T___func__:
3422                 return parse_function_keyword();
3423         case T___PRETTY_FUNCTION__:
3424                 return parse_pretty_function_keyword();
3425         case T___builtin_offsetof:
3426                 return parse_offsetof();
3427         case T___builtin_va_start:
3428                 return parse_va_start();
3429         case T___builtin_va_arg:
3430                 return parse_va_arg();
3431         case T___builtin_nanf:
3432         case T___builtin_alloca:
3433         case T___builtin_expect:
3434         case T___builtin_va_end:
3435                 return parse_builtin_symbol();
3436         case T___builtin_isgreater:
3437         case T___builtin_isgreaterequal:
3438         case T___builtin_isless:
3439         case T___builtin_islessequal:
3440         case T___builtin_islessgreater:
3441         case T___builtin_isunordered:
3442                 return parse_compare_builtin();
3443
3444         case '(':
3445                 return parse_brace_expression();
3446         }
3447
3448         parser_print_error_prefix();
3449         fprintf(stderr, "unexpected token ");
3450         print_token(stderr, &token);
3451         fprintf(stderr, "\n");
3452         eat_statement();
3453
3454         return create_invalid_expression();
3455 }
3456
3457 static expression_t *parse_array_expression(unsigned precedence,
3458                                             expression_t *left)
3459 {
3460         (void) precedence;
3461
3462         eat('[');
3463
3464         expression_t *inside = parse_expression();
3465
3466         array_access_expression_t *array_access
3467                 = allocate_ast_zero(sizeof(array_access[0]));
3468
3469         array_access->expression.type = EXPR_ARRAY_ACCESS;
3470
3471         type_t *type_left   = left->base.datatype;
3472         type_t *type_inside = inside->base.datatype;
3473         type_t *return_type = NULL;
3474
3475         if(type_left != NULL && type_inside != NULL) {
3476                 type_left   = skip_typeref(type_left);
3477                 type_inside = skip_typeref(type_inside);
3478
3479                 if(is_type_pointer(type_left)) {
3480                         pointer_type_t *pointer = &type_left->pointer;
3481                         return_type             = pointer->points_to;
3482                         array_access->array_ref = left;
3483                         array_access->index     = inside;
3484                 } else if(is_type_pointer(type_inside)) {
3485                         pointer_type_t *pointer = &type_inside->pointer;
3486                         return_type             = pointer->points_to;
3487                         array_access->array_ref = inside;
3488                         array_access->index     = left;
3489                         array_access->flipped   = true;
3490                 } else {
3491                         parser_print_error_prefix();
3492                         fprintf(stderr, "array access on object with non-pointer types ");
3493                         print_type_quoted(type_left);
3494                         fprintf(stderr, ", ");
3495                         print_type_quoted(type_inside);
3496                         fprintf(stderr, "\n");
3497                 }
3498         } else {
3499                 array_access->array_ref = left;
3500                 array_access->index     = inside;
3501         }
3502
3503         if(token.type != ']') {
3504                 parse_error_expected("Problem while parsing array access", ']', 0);
3505                 return (expression_t*) array_access;
3506         }
3507         next_token();
3508
3509         return_type = automatic_type_conversion(return_type);
3510         array_access->expression.datatype = return_type;
3511
3512         return (expression_t*) array_access;
3513 }
3514
3515 static expression_t *parse_sizeof(unsigned precedence)
3516 {
3517         eat(T_sizeof);
3518
3519         sizeof_expression_t *sizeof_expression
3520                 = allocate_ast_zero(sizeof(sizeof_expression[0]));
3521         sizeof_expression->expression.type     = EXPR_SIZEOF;
3522         sizeof_expression->expression.datatype = type_size_t;
3523
3524         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
3525                 next_token();
3526                 sizeof_expression->type = parse_typename();
3527                 expect(')');
3528         } else {
3529                 expression_t *expression  = parse_sub_expression(precedence);
3530                 expression->base.datatype = revert_automatic_type_conversion(expression);
3531
3532                 sizeof_expression->type            = expression->base.datatype;
3533                 sizeof_expression->size_expression = expression;
3534         }
3535
3536         return (expression_t*) sizeof_expression;
3537 }
3538
3539 static expression_t *parse_select_expression(unsigned precedence,
3540                                              expression_t *compound)
3541 {
3542         (void) precedence;
3543         assert(token.type == '.' || token.type == T_MINUSGREATER);
3544
3545         bool is_pointer = (token.type == T_MINUSGREATER);
3546         next_token();
3547
3548         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
3549         select->select.compound = compound;
3550
3551         if(token.type != T_IDENTIFIER) {
3552                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
3553                 return select;
3554         }
3555         symbol_t *symbol      = token.v.symbol;
3556         select->select.symbol = symbol;
3557         next_token();
3558
3559         type_t *orig_type = compound->base.datatype;
3560         if(orig_type == NULL)
3561                 return create_invalid_expression();
3562
3563         type_t *type = skip_typeref(orig_type);
3564
3565         type_t *type_left = type;
3566         if(is_pointer) {
3567                 if(type->type != TYPE_POINTER) {
3568                         parser_print_error_prefix();
3569                         fprintf(stderr, "left hand side of '->' is not a pointer, but ");
3570                         print_type_quoted(orig_type);
3571                         fputc('\n', stderr);
3572                         return create_invalid_expression();
3573                 }
3574                 pointer_type_t *pointer_type = &type->pointer;
3575                 type_left                    = pointer_type->points_to;
3576         }
3577         type_left = skip_typeref(type_left);
3578
3579         if(type_left->type != TYPE_COMPOUND_STRUCT
3580                         && type_left->type != TYPE_COMPOUND_UNION) {
3581                 parser_print_error_prefix();
3582                 fprintf(stderr, "request for member '%s' in something not a struct or "
3583                         "union, but ", symbol->string);
3584                 print_type_quoted(type_left);
3585                 fputc('\n', stderr);
3586                 return create_invalid_expression();
3587         }
3588
3589         compound_type_t *compound_type = &type_left->compound;
3590         declaration_t   *declaration   = compound_type->declaration;
3591
3592         if(!declaration->init.is_defined) {
3593                 parser_print_error_prefix();
3594                 fprintf(stderr, "request for member '%s' of incomplete type ",
3595                         symbol->string);
3596                 print_type_quoted(type_left);
3597                 fputc('\n', stderr);
3598                 return create_invalid_expression();
3599         }
3600
3601         declaration_t *iter = declaration->context.declarations;
3602         for( ; iter != NULL; iter = iter->next) {
3603                 if(iter->symbol == symbol) {
3604                         break;
3605                 }
3606         }
3607         if(iter == NULL) {
3608                 parser_print_error_prefix();
3609                 print_type_quoted(type_left);
3610                 fprintf(stderr, " has no member named '%s'\n", symbol->string);
3611                 return create_invalid_expression();
3612         }
3613
3614         /* we always do the auto-type conversions; the & and sizeof parser contains
3615          * code to revert this! */
3616         type_t *expression_type = automatic_type_conversion(iter->type);
3617
3618         select->select.compound_entry = iter;
3619         select->base.datatype         = expression_type;
3620         return select;
3621 }
3622
3623 static expression_t *parse_call_expression(unsigned precedence,
3624                                            expression_t *expression)
3625 {
3626         (void) precedence;
3627         expression_t *result = allocate_expression_zero(EXPR_CALL);
3628
3629         call_expression_t *call  = &result->call;
3630         call->function           = expression;
3631
3632         function_type_t *function_type = NULL;
3633         type_t          *orig_type     = expression->base.datatype;
3634         if(orig_type != NULL) {
3635                 type_t *type  = skip_typeref(orig_type);
3636
3637                 if(is_type_pointer(type)) {
3638                         pointer_type_t *pointer_type = &type->pointer;
3639
3640                         type = skip_typeref(pointer_type->points_to);
3641
3642                         if (is_type_function(type)) {
3643                                 function_type             = &type->function;
3644                                 call->expression.datatype = function_type->return_type;
3645                         }
3646                 }
3647                 if(function_type == NULL) {
3648                         parser_print_error_prefix();
3649                         fputs("called object '", stderr);
3650                         print_expression(expression);
3651                         fputs("' (type ", stderr);
3652                         print_type_quoted(orig_type);
3653                         fputs(") is not a pointer to a function\n", stderr);
3654
3655                         function_type             = NULL;
3656                         call->expression.datatype = NULL;
3657                 }
3658         }
3659
3660         /* parse arguments */
3661         eat('(');
3662
3663         if(token.type != ')') {
3664                 call_argument_t *last_argument = NULL;
3665
3666                 while(true) {
3667                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
3668
3669                         argument->expression = parse_assignment_expression();
3670                         if(last_argument == NULL) {
3671                                 call->arguments = argument;
3672                         } else {
3673                                 last_argument->next = argument;
3674                         }
3675                         last_argument = argument;
3676
3677                         if(token.type != ',')
3678                                 break;
3679                         next_token();
3680                 }
3681         }
3682         expect(')');
3683
3684         if(function_type != NULL) {
3685                 function_parameter_t *parameter = function_type->parameters;
3686                 call_argument_t      *argument  = call->arguments;
3687                 for( ; parameter != NULL && argument != NULL;
3688                                 parameter = parameter->next, argument = argument->next) {
3689                         type_t *expected_type = parameter->type;
3690                         /* TODO report context in error messages */
3691                         argument->expression = create_implicit_cast(argument->expression,
3692                                                                     expected_type);
3693                 }
3694                 /* too few parameters */
3695                 if(parameter != NULL) {
3696                         parser_print_error_prefix();
3697                         fprintf(stderr, "too few arguments to function '");
3698                         print_expression(expression);
3699                         fprintf(stderr, "'\n");
3700                 } else if(argument != NULL) {
3701                         /* too many parameters */
3702                         if(!function_type->variadic
3703                                         && !function_type->unspecified_parameters) {
3704                                 parser_print_error_prefix();
3705                                 fprintf(stderr, "too many arguments to function '");
3706                                 print_expression(expression);
3707                                 fprintf(stderr, "'\n");
3708                         } else {
3709                                 /* do default promotion */
3710                                 for( ; argument != NULL; argument = argument->next) {
3711                                         type_t *type = argument->expression->base.datatype;
3712
3713                                         if(type == NULL)
3714                                                 continue;
3715
3716                                         type = skip_typeref(type);
3717                                         if(is_type_integer(type)) {
3718                                                 type = promote_integer(type);
3719                                         } else if(type == type_float) {
3720                                                 type = type_double;
3721                                         }
3722
3723                                         argument->expression
3724                                                 = create_implicit_cast(argument->expression, type);
3725                                 }
3726                         }
3727                 }
3728         }
3729
3730         return result;
3731 }
3732
3733 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
3734
3735 static bool same_compound_type(const type_t *type1, const type_t *type2)
3736 {
3737         if(!is_type_compound(type1))
3738                 return false;
3739         if(type1->type != type2->type)
3740                 return false;
3741
3742         const compound_type_t *compound1 = &type1->compound;
3743         const compound_type_t *compound2 = &type2->compound;
3744
3745         return compound1->declaration == compound2->declaration;
3746 }
3747
3748 static expression_t *parse_conditional_expression(unsigned precedence,
3749                                                   expression_t *expression)
3750 {
3751         eat('?');
3752
3753         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
3754
3755         conditional_expression_t *conditional = &result->conditional;
3756         conditional->condition = expression;
3757
3758         /* 6.5.15.2 */
3759         type_t *condition_type_orig = expression->base.datatype;
3760         if(condition_type_orig != NULL) {
3761                 type_t *condition_type = skip_typeref(condition_type_orig);
3762                 if(condition_type != NULL && !is_type_scalar(condition_type)) {
3763                         type_error("expected a scalar type in conditional condition",
3764                                    expression->base.source_position, condition_type_orig);
3765                 }
3766         }
3767
3768         expression_t *true_expression = parse_expression();
3769         expect(':');
3770         expression_t *false_expression = parse_sub_expression(precedence);
3771
3772         conditional->true_expression  = true_expression;
3773         conditional->false_expression = false_expression;
3774
3775         type_t *orig_true_type  = true_expression->base.datatype;
3776         type_t *orig_false_type = false_expression->base.datatype;
3777         if(orig_true_type == NULL || orig_false_type == NULL)
3778                 return result;
3779
3780         type_t *true_type  = skip_typeref(orig_true_type);
3781         type_t *false_type = skip_typeref(orig_false_type);
3782
3783         /* 6.5.15.3 */
3784         type_t *result_type = NULL;
3785         if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
3786                 result_type = semantic_arithmetic(true_type, false_type);
3787
3788                 true_expression  = create_implicit_cast(true_expression, result_type);
3789                 false_expression = create_implicit_cast(false_expression, result_type);
3790
3791                 conditional->true_expression     = true_expression;
3792                 conditional->false_expression    = false_expression;
3793                 conditional->expression.datatype = result_type;
3794         } else if (same_compound_type(true_type, false_type)
3795                         || (is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
3796                                 is_type_atomic(false_type, ATOMIC_TYPE_VOID))) {
3797                 /* just take 1 of the 2 types */
3798                 result_type = true_type;
3799         } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
3800                         && pointers_compatible(true_type, false_type)) {
3801                 /* ok */
3802                 result_type = true_type;
3803         } else {
3804                 /* TODO */
3805                 type_error_incompatible("while parsing conditional",
3806                                         expression->base.source_position, true_type,
3807                                         false_type);
3808         }
3809
3810         conditional->expression.datatype = result_type;
3811         return result;
3812 }
3813
3814 static expression_t *parse_extension(unsigned precedence)
3815 {
3816         eat(T___extension__);
3817
3818         /* TODO enable extensions */
3819
3820         return parse_sub_expression(precedence);
3821 }
3822
3823 static expression_t *parse_builtin_classify_type(const unsigned precedence)
3824 {
3825         eat(T___builtin_classify_type);
3826
3827         expression_t *result  = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
3828         result->base.datatype = type_int;
3829
3830         expect('(');
3831         expression_t *expression = parse_sub_expression(precedence);
3832         expect(')');
3833         result->classify_type.type_expression = expression;
3834
3835         return result;
3836 }
3837
3838 static void semantic_incdec(unary_expression_t *expression)
3839 {
3840         type_t *orig_type = expression->value->base.datatype;
3841         if(orig_type == NULL)
3842                 return;
3843
3844         type_t *type = skip_typeref(orig_type);
3845         if(!is_type_arithmetic(type) && type->type != TYPE_POINTER) {
3846                 /* TODO: improve error message */
3847                 parser_print_error_prefix();
3848                 fprintf(stderr, "operation needs an arithmetic or pointer type\n");
3849                 return;
3850         }
3851
3852         expression->expression.datatype = orig_type;
3853 }
3854
3855 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
3856 {
3857         type_t *orig_type = expression->value->base.datatype;
3858         if(orig_type == NULL)
3859                 return;
3860
3861         type_t *type = skip_typeref(orig_type);
3862         if(!is_type_arithmetic(type)) {
3863                 /* TODO: improve error message */
3864                 parser_print_error_prefix();
3865                 fprintf(stderr, "operation needs an arithmetic type\n");
3866                 return;
3867         }
3868
3869         expression->expression.datatype = orig_type;
3870 }
3871
3872 static void semantic_unexpr_scalar(unary_expression_t *expression)
3873 {
3874         type_t *orig_type = expression->value->base.datatype;
3875         if(orig_type == NULL)
3876                 return;
3877
3878         type_t *type = skip_typeref(orig_type);
3879         if (!is_type_scalar(type)) {
3880                 parse_error("operand of ! must be of scalar type\n");
3881                 return;
3882         }
3883
3884         expression->expression.datatype = orig_type;
3885 }
3886
3887 static void semantic_unexpr_integer(unary_expression_t *expression)
3888 {
3889         type_t *orig_type = expression->value->base.datatype;
3890         if(orig_type == NULL)
3891                 return;
3892
3893         type_t *type = skip_typeref(orig_type);
3894         if (!is_type_integer(type)) {
3895                 parse_error("operand of ~ must be of integer type\n");
3896                 return;
3897         }
3898
3899         expression->expression.datatype = orig_type;
3900 }
3901
3902 static void semantic_dereference(unary_expression_t *expression)
3903 {
3904         type_t *orig_type = expression->value->base.datatype;
3905         if(orig_type == NULL)
3906                 return;
3907
3908         type_t *type = skip_typeref(orig_type);
3909         if(!is_type_pointer(type)) {
3910                 parser_print_error_prefix();
3911                 fputs("Unary '*' needs pointer or arrray type, but type ", stderr);
3912                 print_type_quoted(orig_type);
3913                 fputs(" given.\n", stderr);
3914                 return;
3915         }
3916
3917         pointer_type_t *pointer_type = &type->pointer;
3918         type_t         *result_type  = pointer_type->points_to;
3919
3920         result_type = automatic_type_conversion(result_type);
3921         expression->expression.datatype = result_type;
3922 }
3923
3924 static void semantic_take_addr(unary_expression_t *expression)
3925 {
3926         expression_t *value  = expression->value;
3927         value->base.datatype = revert_automatic_type_conversion(value);
3928
3929         type_t *orig_type = value->base.datatype;
3930         if(orig_type == NULL)
3931                 return;
3932
3933         if(value->type == EXPR_REFERENCE) {
3934                 reference_expression_t *reference   = (reference_expression_t*) value;
3935                 declaration_t          *declaration = reference->declaration;
3936                 if(declaration != NULL) {
3937                         declaration->address_taken = 1;
3938                 }
3939         }
3940
3941         expression->expression.datatype = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3942 }
3943
3944 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
3945 static expression_t *parse_##unexpression_type(unsigned precedence)            \
3946 {                                                                              \
3947         eat(token_type);                                                           \
3948                                                                                \
3949         expression_t *unary_expression                                             \
3950                 = allocate_expression_zero(unexpression_type);                         \
3951         unary_expression->unary.value = parse_sub_expression(precedence);          \
3952                                                                                    \
3953         sfunc(&unary_expression->unary);                                           \
3954                                                                                \
3955         return unary_expression;                                                   \
3956 }
3957
3958 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
3959                                semantic_unexpr_arithmetic)
3960 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
3961                                semantic_unexpr_arithmetic)
3962 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
3963                                semantic_unexpr_scalar)
3964 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
3965                                semantic_dereference)
3966 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
3967                                semantic_take_addr)
3968 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
3969                                semantic_unexpr_integer)
3970 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
3971                                semantic_incdec)
3972 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
3973                                semantic_incdec)
3974
3975 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
3976                                                sfunc)                         \
3977 static expression_t *parse_##unexpression_type(unsigned precedence,           \
3978                                                expression_t *left)            \
3979 {                                                                             \
3980         (void) precedence;                                                        \
3981         eat(token_type);                                                          \
3982                                                                               \
3983         expression_t *unary_expression                                            \
3984                 = allocate_expression_zero(unexpression_type);                        \
3985         unary_expression->unary.value = left;                                     \
3986                                                                                   \
3987         sfunc(&unary_expression->unary);                                          \
3988                                                                               \
3989         return unary_expression;                                                  \
3990 }
3991
3992 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
3993                                        EXPR_UNARY_POSTFIX_INCREMENT,
3994                                        semantic_incdec)
3995 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
3996                                        EXPR_UNARY_POSTFIX_DECREMENT,
3997                                        semantic_incdec)
3998
3999 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
4000 {
4001         /* TODO: handle complex + imaginary types */
4002
4003         /* § 6.3.1.8 Usual arithmetic conversions */
4004         if(type_left == type_long_double || type_right == type_long_double) {
4005                 return type_long_double;
4006         } else if(type_left == type_double || type_right == type_double) {
4007                 return type_double;
4008         } else if(type_left == type_float || type_right == type_float) {
4009                 return type_float;
4010         }
4011
4012         type_right = promote_integer(type_right);
4013         type_left  = promote_integer(type_left);
4014
4015         if(type_left == type_right)
4016                 return type_left;
4017
4018         bool signed_left  = is_type_signed(type_left);
4019         bool signed_right = is_type_signed(type_right);
4020         int  rank_left    = get_rank(type_left);
4021         int  rank_right   = get_rank(type_right);
4022         if(rank_left < rank_right) {
4023                 if(signed_left == signed_right || !signed_right) {
4024                         return type_right;
4025                 } else {
4026                         return type_left;
4027                 }
4028         } else {
4029                 if(signed_left == signed_right || !signed_left) {
4030                         return type_left;
4031                 } else {
4032                         return type_right;
4033                 }
4034         }
4035 }
4036
4037 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
4038 {
4039         expression_t *left       = expression->left;
4040         expression_t *right      = expression->right;
4041         type_t       *orig_type_left  = left->base.datatype;
4042         type_t       *orig_type_right = right->base.datatype;
4043
4044         if(orig_type_left == NULL || orig_type_right == NULL)
4045                 return;
4046
4047         type_t *type_left  = skip_typeref(orig_type_left);
4048         type_t *type_right = skip_typeref(orig_type_right);
4049
4050         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4051                 /* TODO: improve error message */
4052                 parser_print_error_prefix();
4053                 fprintf(stderr, "operation needs arithmetic types\n");
4054                 return;
4055         }
4056
4057         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4058         expression->left  = create_implicit_cast(left, arithmetic_type);
4059         expression->right = create_implicit_cast(right, arithmetic_type);
4060         expression->expression.datatype = arithmetic_type;
4061 }
4062
4063 static void semantic_shift_op(binary_expression_t *expression)
4064 {
4065         expression_t *left       = expression->left;
4066         expression_t *right      = expression->right;
4067         type_t       *orig_type_left  = left->base.datatype;
4068         type_t       *orig_type_right = right->base.datatype;
4069
4070         if(orig_type_left == NULL || orig_type_right == NULL)
4071                 return;
4072
4073         type_t *type_left  = skip_typeref(orig_type_left);
4074         type_t *type_right = skip_typeref(orig_type_right);
4075
4076         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
4077                 /* TODO: improve error message */
4078                 parser_print_error_prefix();
4079                 fprintf(stderr, "operation needs integer types\n");
4080                 return;
4081         }
4082
4083         type_left  = promote_integer(type_left);
4084         type_right = promote_integer(type_right);
4085
4086         expression->left  = create_implicit_cast(left, type_left);
4087         expression->right = create_implicit_cast(right, type_right);
4088         expression->expression.datatype = type_left;
4089 }
4090
4091 static void semantic_add(binary_expression_t *expression)
4092 {
4093         expression_t *left            = expression->left;
4094         expression_t *right           = expression->right;
4095         type_t       *orig_type_left  = left->base.datatype;
4096         type_t       *orig_type_right = right->base.datatype;
4097
4098         if(orig_type_left == NULL || orig_type_right == NULL)
4099                 return;
4100
4101         type_t *type_left  = skip_typeref(orig_type_left);
4102         type_t *type_right = skip_typeref(orig_type_right);
4103
4104         /* § 5.6.5 */
4105         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4106                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4107                 expression->left  = create_implicit_cast(left, arithmetic_type);
4108                 expression->right = create_implicit_cast(right, arithmetic_type);
4109                 expression->expression.datatype = arithmetic_type;
4110                 return;
4111         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4112                 expression->expression.datatype = type_left;
4113         } else if(is_type_pointer(type_right) && is_type_integer(type_left)) {
4114                 expression->expression.datatype = type_right;
4115         } else {
4116                 parser_print_error_prefix();
4117                 fprintf(stderr, "invalid operands to binary + (");
4118                 print_type_quoted(orig_type_left);
4119                 fprintf(stderr, ", ");
4120                 print_type_quoted(orig_type_right);
4121                 fprintf(stderr, ")\n");
4122         }
4123 }
4124
4125 static void semantic_sub(binary_expression_t *expression)
4126 {
4127         expression_t *left            = expression->left;
4128         expression_t *right           = expression->right;
4129         type_t       *orig_type_left  = left->base.datatype;
4130         type_t       *orig_type_right = right->base.datatype;
4131
4132         if(orig_type_left == NULL || orig_type_right == NULL)
4133                 return;
4134
4135         type_t       *type_left       = skip_typeref(orig_type_left);
4136         type_t       *type_right      = skip_typeref(orig_type_right);
4137
4138         /* § 5.6.5 */
4139         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4140                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4141                 expression->left  = create_implicit_cast(left, arithmetic_type);
4142                 expression->right = create_implicit_cast(right, arithmetic_type);
4143                 expression->expression.datatype = arithmetic_type;
4144                 return;
4145         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4146                 expression->expression.datatype = type_left;
4147         } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
4148                 if(!pointers_compatible(type_left, type_right)) {
4149                         parser_print_error_prefix();
4150                         fprintf(stderr, "pointers to incompatible objects to binary - (");
4151                         print_type_quoted(orig_type_left);
4152                         fprintf(stderr, ", ");
4153                         print_type_quoted(orig_type_right);
4154                         fprintf(stderr, ")\n");
4155                 } else {
4156                         expression->expression.datatype = type_ptrdiff_t;
4157                 }
4158         } else {
4159                 parser_print_error_prefix();
4160                 fprintf(stderr, "invalid operands to binary - (");
4161                 print_type_quoted(orig_type_left);
4162                 fprintf(stderr, ", ");
4163                 print_type_quoted(orig_type_right);
4164                 fprintf(stderr, ")\n");
4165         }
4166 }
4167
4168 static void semantic_comparison(binary_expression_t *expression)
4169 {
4170         expression_t *left            = expression->left;
4171         expression_t *right           = expression->right;
4172         type_t       *orig_type_left  = left->base.datatype;
4173         type_t       *orig_type_right = right->base.datatype;
4174
4175         if(orig_type_left == NULL || orig_type_right == NULL)
4176                 return;
4177
4178         type_t *type_left  = skip_typeref(orig_type_left);
4179         type_t *type_right = skip_typeref(orig_type_right);
4180
4181         /* TODO non-arithmetic types */
4182         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4183                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4184                 expression->left  = create_implicit_cast(left, arithmetic_type);
4185                 expression->right = create_implicit_cast(right, arithmetic_type);
4186                 expression->expression.datatype = arithmetic_type;
4187         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
4188                 /* TODO check compatibility */
4189         } else if (is_type_pointer(type_left)) {
4190                 expression->right = create_implicit_cast(right, type_left);
4191         } else if (is_type_pointer(type_right)) {
4192                 expression->left = create_implicit_cast(left, type_right);
4193         } else {
4194                 type_error_incompatible("invalid operands in comparison",
4195                                         token.source_position, type_left, type_right);
4196         }
4197         expression->expression.datatype = type_int;
4198 }
4199
4200 static void semantic_arithmetic_assign(binary_expression_t *expression)
4201 {
4202         expression_t *left            = expression->left;
4203         expression_t *right           = expression->right;
4204         type_t       *orig_type_left  = left->base.datatype;
4205         type_t       *orig_type_right = right->base.datatype;
4206
4207         if(orig_type_left == NULL || orig_type_right == NULL)
4208                 return;
4209
4210         type_t *type_left  = skip_typeref(orig_type_left);
4211         type_t *type_right = skip_typeref(orig_type_right);
4212
4213         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4214                 /* TODO: improve error message */
4215                 parser_print_error_prefix();
4216                 fprintf(stderr, "operation needs arithmetic types\n");
4217                 return;
4218         }
4219
4220         /* combined instructions are tricky. We can't create an implicit cast on
4221          * the left side, because we need the uncasted form for the store.
4222          * The ast2firm pass has to know that left_type must be right_type
4223          * for the arithmeitc operation and create a cast by itself */
4224         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4225         expression->right       = create_implicit_cast(right, arithmetic_type);
4226         expression->expression.datatype = type_left;
4227 }
4228
4229 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
4230 {
4231         expression_t *left            = expression->left;
4232         expression_t *right           = expression->right;
4233         type_t       *orig_type_left  = left->base.datatype;
4234         type_t       *orig_type_right = right->base.datatype;
4235
4236         if(orig_type_left == NULL || orig_type_right == NULL)
4237                 return;
4238
4239         type_t *type_left  = skip_typeref(orig_type_left);
4240         type_t *type_right = skip_typeref(orig_type_right);
4241
4242         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4243                 /* combined instructions are tricky. We can't create an implicit cast on
4244                  * the left side, because we need the uncasted form for the store.
4245                  * The ast2firm pass has to know that left_type must be right_type
4246                  * for the arithmeitc operation and create a cast by itself */
4247                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
4248                 expression->right = create_implicit_cast(right, arithmetic_type);
4249                 expression->expression.datatype = type_left;
4250         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
4251                 expression->expression.datatype = type_left;
4252         } else {
4253                 parser_print_error_prefix();
4254                 fputs("Incompatible types ", stderr);
4255                 print_type_quoted(orig_type_left);
4256                 fputs(" and ", stderr);
4257                 print_type_quoted(orig_type_right);
4258                 fputs(" in assignment\n", stderr);
4259                 return;
4260         }
4261 }
4262
4263 static void semantic_logical_op(binary_expression_t *expression)
4264 {
4265         expression_t *left            = expression->left;
4266         expression_t *right           = expression->right;
4267         type_t       *orig_type_left  = left->base.datatype;
4268         type_t       *orig_type_right = right->base.datatype;
4269
4270         if(orig_type_left == NULL || orig_type_right == NULL)
4271                 return;
4272
4273         type_t *type_left  = skip_typeref(orig_type_left);
4274         type_t *type_right = skip_typeref(orig_type_right);
4275
4276         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
4277                 /* TODO: improve error message */
4278                 parser_print_error_prefix();
4279                 fprintf(stderr, "operation needs scalar types\n");
4280                 return;
4281         }
4282
4283         expression->expression.datatype = type_int;
4284 }
4285
4286 static bool has_const_fields(type_t *type)
4287 {
4288         (void) type;
4289         /* TODO */
4290         return false;
4291 }
4292
4293 static void semantic_binexpr_assign(binary_expression_t *expression)
4294 {
4295         expression_t *left           = expression->left;
4296         type_t       *orig_type_left = left->base.datatype;
4297
4298         if(orig_type_left == NULL)
4299                 return;
4300
4301         type_t *type_left = revert_automatic_type_conversion(left);
4302         type_left         = skip_typeref(orig_type_left);
4303
4304         /* must be a modifiable lvalue */
4305         if (is_type_array(type_left)) {
4306                 parser_print_error_prefix();
4307                 fprintf(stderr, "Cannot assign to arrays ('");
4308                 print_expression(left);
4309                 fprintf(stderr, "')\n");
4310                 return;
4311         }
4312         if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
4313                 parser_print_error_prefix();
4314                 fprintf(stderr, "assignment to readonly location '");
4315                 print_expression(left);
4316                 fprintf(stderr, "' (type ");
4317                 print_type_quoted(orig_type_left);
4318                 fprintf(stderr, ")\n");
4319                 return;
4320         }
4321         if(is_type_incomplete(type_left)) {
4322                 parser_print_error_prefix();
4323                 fprintf(stderr, "left-hand side of assignment '");
4324                 print_expression(left);
4325                 fprintf(stderr, "' has incomplete type ");
4326                 print_type_quoted(orig_type_left);
4327                 fprintf(stderr, "\n");
4328                 return;
4329         }
4330         if(is_type_compound(type_left) && has_const_fields(type_left)) {
4331                 parser_print_error_prefix();
4332                 fprintf(stderr, "can't assign to '");
4333                 print_expression(left);
4334                 fprintf(stderr, "' because compound type ");
4335                 print_type_quoted(orig_type_left);
4336                 fprintf(stderr, " has readonly fields\n");
4337                 return;
4338         }
4339
4340         semantic_assign(orig_type_left, &expression->right, "assignment");
4341
4342         expression->expression.datatype = orig_type_left;
4343 }
4344
4345 static void semantic_comma(binary_expression_t *expression)
4346 {
4347         expression->expression.datatype = expression->right->base.datatype;
4348 }
4349
4350 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
4351 static expression_t *parse_##binexpression_type(unsigned precedence,      \
4352                                                 expression_t *left)       \
4353 {                                                                         \
4354         eat(token_type);                                                      \
4355                                                                           \
4356         expression_t *right = parse_sub_expression(precedence + lr);          \
4357                                                                           \
4358         expression_t *binexpr = allocate_expression_zero(binexpression_type); \
4359         binexpr->binary.left  = left;                                         \
4360         binexpr->binary.right = right;                                        \
4361         sfunc(&binexpr->binary);                                              \
4362                                                                           \
4363         return binexpr;                                                       \
4364 }
4365
4366 CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
4367 CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
4368 CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
4369 CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
4370 CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
4371 CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
4372 CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
4373 CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
4374 CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
4375
4376 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
4377                       semantic_comparison, 1)
4378 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
4379                       semantic_comparison, 1)
4380 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
4381                       semantic_comparison, 1)
4382 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
4383                       semantic_comparison, 1)
4384
4385 CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
4386                       semantic_binexpr_arithmetic, 1)
4387 CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
4388                       semantic_binexpr_arithmetic, 1)
4389 CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
4390                       semantic_binexpr_arithmetic, 1)
4391 CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
4392                       semantic_logical_op, 1)
4393 CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
4394                       semantic_logical_op, 1)
4395 CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
4396                       semantic_shift_op, 1)
4397 CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
4398                       semantic_shift_op, 1)
4399 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
4400                       semantic_arithmetic_addsubb_assign, 0)
4401 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
4402                       semantic_arithmetic_addsubb_assign, 0)
4403 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
4404                       semantic_arithmetic_assign, 0)
4405 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
4406                       semantic_arithmetic_assign, 0)
4407 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
4408                       semantic_arithmetic_assign, 0)
4409 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
4410                       semantic_arithmetic_assign, 0)
4411 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4412                       semantic_arithmetic_assign, 0)
4413 CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
4414                       semantic_arithmetic_assign, 0)
4415 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
4416                       semantic_arithmetic_assign, 0)
4417 CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
4418                       semantic_arithmetic_assign, 0)
4419
4420 static expression_t *parse_sub_expression(unsigned precedence)
4421 {
4422         if(token.type < 0) {
4423                 return expected_expression_error();
4424         }
4425
4426         expression_parser_function_t *parser
4427                 = &expression_parsers[token.type];
4428         source_position_t             source_position = token.source_position;
4429         expression_t                 *left;
4430
4431         if(parser->parser != NULL) {
4432                 left = parser->parser(parser->precedence);
4433         } else {
4434                 left = parse_primary_expression();
4435         }
4436         assert(left != NULL);
4437         left->base.source_position = source_position;
4438
4439         while(true) {
4440                 if(token.type < 0) {
4441                         return expected_expression_error();
4442                 }
4443
4444                 parser = &expression_parsers[token.type];
4445                 if(parser->infix_parser == NULL)
4446                         break;
4447                 if(parser->infix_precedence < precedence)
4448                         break;
4449
4450                 left = parser->infix_parser(parser->infix_precedence, left);
4451
4452                 assert(left != NULL);
4453                 assert(left->type != EXPR_UNKNOWN);
4454                 left->base.source_position = source_position;
4455         }
4456
4457         return left;
4458 }
4459
4460 static expression_t *parse_expression(void)
4461 {
4462         return parse_sub_expression(1);
4463 }
4464
4465
4466
4467 static void register_expression_parser(parse_expression_function parser,
4468                                        int token_type, unsigned precedence)
4469 {
4470         expression_parser_function_t *entry = &expression_parsers[token_type];
4471
4472         if(entry->parser != NULL) {
4473                 fprintf(stderr, "for token ");
4474                 print_token_type(stderr, (token_type_t) token_type);
4475                 fprintf(stderr, "\n");
4476                 panic("trying to register multiple expression parsers for a token");
4477         }
4478         entry->parser     = parser;
4479         entry->precedence = precedence;
4480 }
4481
4482 static void register_infix_parser(parse_expression_infix_function parser,
4483                 int token_type, unsigned precedence)
4484 {
4485         expression_parser_function_t *entry = &expression_parsers[token_type];
4486
4487         if(entry->infix_parser != NULL) {
4488                 fprintf(stderr, "for token ");
4489                 print_token_type(stderr, (token_type_t) token_type);
4490                 fprintf(stderr, "\n");
4491                 panic("trying to register multiple infix expression parsers for a "
4492                       "token");
4493         }
4494         entry->infix_parser     = parser;
4495         entry->infix_precedence = precedence;
4496 }
4497
4498 static void init_expression_parsers(void)
4499 {
4500         memset(&expression_parsers, 0, sizeof(expression_parsers));
4501
4502         register_infix_parser(parse_array_expression,         '[',              30);
4503         register_infix_parser(parse_call_expression,          '(',              30);
4504         register_infix_parser(parse_select_expression,        '.',              30);
4505         register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
4506         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
4507                                                               T_PLUSPLUS,       30);
4508         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
4509                                                               T_MINUSMINUS,     30);
4510
4511         register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
4512         register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
4513         register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
4514         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
4515         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
4516         register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
4517         register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
4518         register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
4519         register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
4520         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
4521         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
4522         register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
4523         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
4524                                                     T_EXCLAMATIONMARKEQUAL, 13);
4525         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
4526         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
4527         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
4528         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
4529         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
4530         register_infix_parser(parse_conditional_expression,   '?',               7);
4531         register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
4532         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
4533         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
4534         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
4535         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
4536         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
4537         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
4538                                                                 T_LESSLESSEQUAL, 2);
4539         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4540                                                           T_GREATERGREATEREQUAL, 2);
4541         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
4542                                                                      T_ANDEQUAL, 2);
4543         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
4544                                                                     T_PIPEEQUAL, 2);
4545         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
4546                                                                    T_CARETEQUAL, 2);
4547
4548         register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
4549
4550         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
4551         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
4552         register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
4553         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
4554         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
4555         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
4556         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
4557                                                                   T_PLUSPLUS,   25);
4558         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
4559                                                                   T_MINUSMINUS, 25);
4560         register_expression_parser(parse_sizeof,                  T_sizeof,     25);
4561         register_expression_parser(parse_extension,            T___extension__, 25);
4562         register_expression_parser(parse_builtin_classify_type,
4563                                                      T___builtin_classify_type, 25);
4564 }
4565
4566 static asm_constraint_t *parse_asm_constraints(void)
4567 {
4568         asm_constraint_t *result = NULL;
4569         asm_constraint_t *last   = NULL;
4570
4571         while(token.type == T_STRING_LITERAL || token.type == '[') {
4572                 asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
4573                 memset(constraint, 0, sizeof(constraint[0]));
4574
4575                 if(token.type == '[') {
4576                         eat('[');
4577                         if(token.type != T_IDENTIFIER) {
4578                                 parse_error_expected("while parsing asm constraint",
4579                                                      T_IDENTIFIER, 0);
4580                                 return NULL;
4581                         }
4582                         constraint->symbol = token.v.symbol;
4583
4584                         expect(']');
4585                 }
4586
4587                 constraint->constraints = parse_string_literals();
4588                 expect('(');
4589                 constraint->expression = parse_expression();
4590                 expect(')');
4591
4592                 if(last != NULL) {
4593                         last->next = constraint;
4594                 } else {
4595                         result = constraint;
4596                 }
4597                 last = constraint;
4598
4599                 if(token.type != ',')
4600                         break;
4601                 eat(',');
4602         }
4603
4604         return result;
4605 }
4606
4607 static asm_clobber_t *parse_asm_clobbers(void)
4608 {
4609         asm_clobber_t *result = NULL;
4610         asm_clobber_t *last   = NULL;
4611
4612         while(token.type == T_STRING_LITERAL) {
4613                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
4614                 clobber->clobber       = parse_string_literals();
4615
4616                 if(last != NULL) {
4617                         last->next = clobber;
4618                 } else {
4619                         result = clobber;
4620                 }
4621                 last = clobber;
4622
4623                 if(token.type != ',')
4624                         break;
4625                 eat(',');
4626         }
4627
4628         return result;
4629 }
4630
4631 static statement_t *parse_asm_statement(void)
4632 {
4633         eat(T_asm);
4634
4635         statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
4636         statement->base.source_position = token.source_position;
4637
4638         asm_statement_t *asm_statement = &statement->asms;
4639
4640         if(token.type == T_volatile) {
4641                 next_token();
4642                 asm_statement->is_volatile = true;
4643         }
4644
4645         expect('(');
4646         asm_statement->asm_text = parse_string_literals();
4647
4648         if(token.type != ':')
4649                 goto end_of_asm;
4650         eat(':');
4651
4652         asm_statement->inputs = parse_asm_constraints();
4653         if(token.type != ':')
4654                 goto end_of_asm;
4655         eat(':');
4656
4657         asm_statement->outputs = parse_asm_constraints();
4658         if(token.type != ':')
4659                 goto end_of_asm;
4660         eat(':');
4661
4662         asm_statement->clobbers = parse_asm_clobbers();
4663
4664 end_of_asm:
4665         expect(')');
4666         expect(';');
4667         return statement;
4668 }
4669
4670 static statement_t *parse_case_statement(void)
4671 {
4672         eat(T_case);
4673
4674         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
4675
4676         statement->base.source_position  = token.source_position;
4677         statement->case_label.expression = parse_expression();
4678
4679         expect(':');
4680         statement->case_label.label_statement = parse_statement();
4681
4682         return statement;
4683 }
4684
4685 static statement_t *parse_default_statement(void)
4686 {
4687         eat(T_default);
4688
4689         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
4690
4691         statement->base.source_position = token.source_position;
4692
4693         expect(':');
4694         statement->label.label_statement = parse_statement();
4695
4696         return statement;
4697 }
4698
4699 static declaration_t *get_label(symbol_t *symbol)
4700 {
4701         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
4702         assert(current_function != NULL);
4703         /* if we found a label in the same function, then we already created the
4704          * declaration */
4705         if(candidate != NULL
4706                         && candidate->parent_context == &current_function->context) {
4707                 return candidate;
4708         }
4709
4710         /* otherwise we need to create a new one */
4711         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
4712         declaration->namespc       = NAMESPACE_LABEL;
4713         declaration->symbol        = symbol;
4714
4715         label_push(declaration);
4716
4717         return declaration;
4718 }
4719
4720 static statement_t *parse_label_statement(void)
4721 {
4722         assert(token.type == T_IDENTIFIER);
4723         symbol_t *symbol = token.v.symbol;
4724         next_token();
4725
4726         declaration_t *label = get_label(symbol);
4727
4728         /* if source position is already set then the label is defined twice,
4729          * otherwise it was just mentioned in a goto so far */
4730         if(label->source_position.input_name != NULL) {
4731                 parser_print_error_prefix();
4732                 fprintf(stderr, "duplicate label '%s'\n", symbol->string);
4733                 parser_print_error_prefix_pos(label->source_position);
4734                 fprintf(stderr, "previous definition of '%s' was here\n",
4735                         symbol->string);
4736         } else {
4737                 label->source_position = token.source_position;
4738         }
4739
4740         label_statement_t *label_statement = allocate_ast_zero(sizeof(label[0]));
4741
4742         label_statement->statement.type            = STATEMENT_LABEL;
4743         label_statement->statement.source_position = token.source_position;
4744         label_statement->label                     = label;
4745
4746         expect(':');
4747
4748         if(token.type == '}') {
4749                 parse_error("label at end of compound statement");
4750                 return (statement_t*) label_statement;
4751         } else {
4752                 label_statement->label_statement = parse_statement();
4753         }
4754
4755         return (statement_t*) label_statement;
4756 }
4757
4758 static statement_t *parse_if(void)
4759 {
4760         eat(T_if);
4761
4762         if_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4763         statement->statement.type            = STATEMENT_IF;
4764         statement->statement.source_position = token.source_position;
4765
4766         expect('(');
4767         statement->condition = parse_expression();
4768         expect(')');
4769
4770         statement->true_statement = parse_statement();
4771         if(token.type == T_else) {
4772                 next_token();
4773                 statement->false_statement = parse_statement();
4774         }
4775
4776         return (statement_t*) statement;
4777 }
4778
4779 static statement_t *parse_switch(void)
4780 {
4781         eat(T_switch);
4782
4783         switch_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4784         statement->statement.type            = STATEMENT_SWITCH;
4785         statement->statement.source_position = token.source_position;
4786
4787         expect('(');
4788         statement->expression = parse_expression();
4789         expect(')');
4790         statement->body = parse_statement();
4791
4792         return (statement_t*) statement;
4793 }
4794
4795 static statement_t *parse_while(void)
4796 {
4797         eat(T_while);
4798
4799         while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4800         statement->statement.type            = STATEMENT_WHILE;
4801         statement->statement.source_position = token.source_position;
4802
4803         expect('(');
4804         statement->condition = parse_expression();
4805         expect(')');
4806         statement->body = parse_statement();
4807
4808         return (statement_t*) statement;
4809 }
4810
4811 static statement_t *parse_do(void)
4812 {
4813         eat(T_do);
4814
4815         do_while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4816         statement->statement.type            = STATEMENT_DO_WHILE;
4817         statement->statement.source_position = token.source_position;
4818
4819         statement->body = parse_statement();
4820         expect(T_while);
4821         expect('(');
4822         statement->condition = parse_expression();
4823         expect(')');
4824         expect(';');
4825
4826         return (statement_t*) statement;
4827 }
4828
4829 static statement_t *parse_for(void)
4830 {
4831         eat(T_for);
4832
4833         for_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4834         statement->statement.type            = STATEMENT_FOR;
4835         statement->statement.source_position = token.source_position;
4836
4837         expect('(');
4838
4839         int         top          = environment_top();
4840         context_t  *last_context = context;
4841         set_context(&statement->context);
4842
4843         if(token.type != ';') {
4844                 if(is_declaration_specifier(&token, false)) {
4845                         parse_declaration(record_declaration);
4846                 } else {
4847                         statement->initialisation = parse_expression();
4848                         expect(';');
4849                 }
4850         } else {
4851                 expect(';');
4852         }
4853
4854         if(token.type != ';') {
4855                 statement->condition = parse_expression();
4856         }
4857         expect(';');
4858         if(token.type != ')') {
4859                 statement->step = parse_expression();
4860         }
4861         expect(')');
4862         statement->body = parse_statement();
4863
4864         assert(context == &statement->context);
4865         set_context(last_context);
4866         environment_pop_to(top);
4867
4868         return (statement_t*) statement;
4869 }
4870
4871 static statement_t *parse_goto(void)
4872 {
4873         eat(T_goto);
4874
4875         if(token.type != T_IDENTIFIER) {
4876                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
4877                 eat_statement();
4878                 return NULL;
4879         }
4880         symbol_t *symbol = token.v.symbol;
4881         next_token();
4882
4883         declaration_t *label = get_label(symbol);
4884
4885         goto_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4886
4887         statement->statement.type            = STATEMENT_GOTO;
4888         statement->statement.source_position = token.source_position;
4889
4890         statement->label = label;
4891
4892         expect(';');
4893
4894         return (statement_t*) statement;
4895 }
4896
4897 static statement_t *parse_continue(void)
4898 {
4899         eat(T_continue);
4900         expect(';');
4901
4902         statement_t *statement          = allocate_ast_zero(sizeof(statement[0]));
4903         statement->type                 = STATEMENT_CONTINUE;
4904         statement->base.source_position = token.source_position;
4905
4906         return statement;
4907 }
4908
4909 static statement_t *parse_break(void)
4910 {
4911         eat(T_break);
4912         expect(';');
4913
4914         statement_t *statement          = allocate_ast_zero(sizeof(statement[0]));
4915         statement->type                 = STATEMENT_BREAK;
4916         statement->base.source_position = token.source_position;
4917
4918         return statement;
4919 }
4920
4921 static statement_t *parse_return(void)
4922 {
4923         eat(T_return);
4924
4925         return_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4926
4927         statement->statement.type            = STATEMENT_RETURN;
4928         statement->statement.source_position = token.source_position;
4929
4930         assert(is_type_function(current_function->type));
4931         function_type_t *function_type = &current_function->type->function;
4932         type_t          *return_type   = function_type->return_type;
4933
4934         expression_t *return_value = NULL;
4935         if(token.type != ';') {
4936                 return_value = parse_expression();
4937         }
4938         expect(';');
4939
4940         if(return_type == NULL)
4941                 return (statement_t*) statement;
4942         if(return_value != NULL && return_value->base.datatype == NULL)
4943                 return (statement_t*) statement;
4944
4945         return_type = skip_typeref(return_type);
4946
4947         if(return_value != NULL) {
4948                 type_t *return_value_type = skip_typeref(return_value->base.datatype);
4949
4950                 if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
4951                                 && !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
4952                         parse_warning("'return' with a value, in function returning void");
4953                         return_value = NULL;
4954                 } else {
4955                         if(return_type != NULL) {
4956                                 semantic_assign(return_type, &return_value, "'return'");
4957                         }
4958                 }
4959         } else {
4960                 if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
4961                         parse_warning("'return' without value, in function returning "
4962                                       "non-void");
4963                 }
4964         }
4965         statement->return_value = return_value;
4966
4967         return (statement_t*) statement;
4968 }
4969
4970 static statement_t *parse_declaration_statement(void)
4971 {
4972         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
4973
4974         statement->base.source_position = token.source_position;
4975
4976         declaration_t *before = last_declaration;
4977         parse_declaration(record_declaration);
4978
4979         if(before == NULL) {
4980                 statement->declaration.declarations_begin = context->declarations;
4981         } else {
4982                 statement->declaration.declarations_begin = before->next;
4983         }
4984         statement->declaration.declarations_end = last_declaration;
4985
4986         return statement;
4987 }
4988
4989 static statement_t *parse_expression_statement(void)
4990 {
4991         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
4992
4993         statement->base.source_position  = token.source_position;
4994         statement->expression.expression = parse_expression();
4995
4996         expect(';');
4997
4998         return statement;
4999 }
5000
5001 static statement_t *parse_statement(void)
5002 {
5003         statement_t   *statement = NULL;
5004
5005         /* declaration or statement */
5006         switch(token.type) {
5007         case T_asm:
5008                 statement = parse_asm_statement();
5009                 break;
5010
5011         case T_case:
5012                 statement = parse_case_statement();
5013                 break;
5014
5015         case T_default:
5016                 statement = parse_default_statement();
5017                 break;
5018
5019         case '{':
5020                 statement = parse_compound_statement();
5021                 break;
5022
5023         case T_if:
5024                 statement = parse_if();
5025                 break;
5026
5027         case T_switch:
5028                 statement = parse_switch();
5029                 break;
5030
5031         case T_while:
5032                 statement = parse_while();
5033                 break;
5034
5035         case T_do:
5036                 statement = parse_do();
5037                 break;
5038
5039         case T_for:
5040                 statement = parse_for();
5041                 break;
5042
5043         case T_goto:
5044                 statement = parse_goto();
5045                 break;
5046
5047         case T_continue:
5048                 statement = parse_continue();
5049                 break;
5050
5051         case T_break:
5052                 statement = parse_break();
5053                 break;
5054
5055         case T_return:
5056                 statement = parse_return();
5057                 break;
5058
5059         case ';':
5060                 next_token();
5061                 statement = NULL;
5062                 break;
5063
5064         case T_IDENTIFIER:
5065                 if(look_ahead(1)->type == ':') {
5066                         statement = parse_label_statement();
5067                         break;
5068                 }
5069
5070                 if(is_typedef_symbol(token.v.symbol)) {
5071                         statement = parse_declaration_statement();
5072                         break;
5073                 }
5074
5075                 statement = parse_expression_statement();
5076                 break;
5077
5078         case T___extension__:
5079                 /* this can be a prefix to a declaration or an expression statement */
5080                 /* we simply eat it now and parse the rest with tail recursion */
5081                 do {
5082                         next_token();
5083                 } while(token.type == T___extension__);
5084                 statement = parse_statement();
5085                 break;
5086
5087         DECLARATION_START
5088                 statement = parse_declaration_statement();
5089                 break;
5090
5091         default:
5092                 statement = parse_expression_statement();
5093                 break;
5094         }
5095
5096         assert(statement == NULL
5097                         || statement->base.source_position.input_name != NULL);
5098
5099         return statement;
5100 }
5101
5102 static statement_t *parse_compound_statement(void)
5103 {
5104         compound_statement_t *compound_statement
5105                 = allocate_ast_zero(sizeof(compound_statement[0]));
5106         compound_statement->statement.type            = STATEMENT_COMPOUND;
5107         compound_statement->statement.source_position = token.source_position;
5108
5109         eat('{');
5110
5111         int        top          = environment_top();
5112         context_t *last_context = context;
5113         set_context(&compound_statement->context);
5114
5115         statement_t *last_statement = NULL;
5116
5117         while(token.type != '}' && token.type != T_EOF) {
5118                 statement_t *statement = parse_statement();
5119                 if(statement == NULL)
5120                         continue;
5121
5122                 if(last_statement != NULL) {
5123                         last_statement->base.next = statement;
5124                 } else {
5125                         compound_statement->statements = statement;
5126                 }
5127
5128                 while(statement->base.next != NULL)
5129                         statement = statement->base.next;
5130
5131                 last_statement = statement;
5132         }
5133
5134         if(token.type != '}') {
5135                 parser_print_error_prefix_pos(
5136                                 compound_statement->statement.source_position);
5137                 fprintf(stderr, "end of file while looking for closing '}'\n");
5138         }
5139         next_token();
5140
5141         assert(context == &compound_statement->context);
5142         set_context(last_context);
5143         environment_pop_to(top);
5144
5145         return (statement_t*) compound_statement;
5146 }
5147
5148 static void initialize_builtins(void)
5149 {
5150         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__", type_int);
5151         type_wchar_t_ptr = make_pointer_type(type_wchar_t, TYPE_QUALIFIER_NONE);
5152         type_size_t      = make_global_typedef("__SIZE_TYPE__",
5153                         make_atomic_type(ATOMIC_TYPE_ULONG, TYPE_QUALIFIER_NONE));
5154         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",
5155                         make_atomic_type(ATOMIC_TYPE_LONG, TYPE_QUALIFIER_NONE));
5156 }
5157
5158 static translation_unit_t *parse_translation_unit(void)
5159 {
5160         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
5161
5162         assert(global_context == NULL);
5163         global_context = &unit->context;
5164
5165         assert(context == NULL);
5166         set_context(&unit->context);
5167
5168         initialize_builtins();
5169
5170         while(token.type != T_EOF) {
5171                 parse_external_declaration();
5172         }
5173
5174         assert(context == &unit->context);
5175         context          = NULL;
5176         last_declaration = NULL;
5177
5178         assert(global_context == &unit->context);
5179         global_context = NULL;
5180
5181         return unit;
5182 }
5183
5184 translation_unit_t *parse(void)
5185 {
5186         environment_stack = NEW_ARR_F(stack_entry_t, 0);
5187         label_stack       = NEW_ARR_F(stack_entry_t, 0);
5188         found_error       = false;
5189
5190         type_set_output(stderr);
5191         ast_set_output(stderr);
5192
5193         lookahead_bufpos = 0;
5194         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
5195                 next_token();
5196         }
5197         translation_unit_t *unit = parse_translation_unit();
5198
5199         DEL_ARR_F(environment_stack);
5200         DEL_ARR_F(label_stack);
5201
5202         if(found_error)
5203                 return NULL;
5204
5205         return unit;
5206 }
5207
5208 void init_parser(void)
5209 {
5210         init_expression_parsers();
5211         obstack_init(&temp_obst);
5212
5213         type_int         = make_atomic_type(ATOMIC_TYPE_INT, TYPE_QUALIFIER_NONE);
5214         type_long_double = make_atomic_type(ATOMIC_TYPE_LONG_DOUBLE,
5215                                             TYPE_QUALIFIER_NONE);
5216         type_double      = make_atomic_type(ATOMIC_TYPE_DOUBLE,
5217                                             TYPE_QUALIFIER_NONE);
5218         type_float       = make_atomic_type(ATOMIC_TYPE_FLOAT, TYPE_QUALIFIER_NONE);
5219         type_char        = make_atomic_type(ATOMIC_TYPE_CHAR, TYPE_QUALIFIER_NONE);
5220         type_void        = make_atomic_type(ATOMIC_TYPE_VOID, TYPE_QUALIFIER_NONE);
5221         type_void_ptr    = make_pointer_type(type_void, TYPE_QUALIFIER_NONE);
5222         type_string      = make_pointer_type(type_char, TYPE_QUALIFIER_NONE);
5223
5224         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
5225         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
5226 }
5227
5228 void exit_parser(void)
5229 {
5230         obstack_free(&temp_obst, NULL);
5231 }