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