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(void)
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->symbol          = token.v.symbol;
1239                 entry->source_position = token.source_position;
1240                 next_token();
1241
1242                 if(token.type == '=') {
1243                         next_token();
1244                         entry->init.enum_value = parse_constant_expression();
1245                 }
1246
1247                 record_declaration(entry);
1248
1249                 if(token.type != ',')
1250                         break;
1251                 next_token();
1252         } while(token.type != '}');
1253
1254         expect_void('}');
1255 }
1256
1257 static declaration_t *parse_enum_specifier(void)
1258 {
1259         eat(T_enum);
1260
1261         declaration_t *declaration;
1262         symbol_t      *symbol;
1263
1264         if(token.type == T_IDENTIFIER) {
1265                 symbol = token.v.symbol;
1266                 next_token();
1267
1268                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1269         } else if(token.type != '{') {
1270                 parse_error_expected("while parsing enum type specifier",
1271                                      T_IDENTIFIER, '{', 0);
1272                 return NULL;
1273         } else {
1274                 declaration = NULL;
1275                 symbol      = NULL;
1276         }
1277
1278         if(declaration == NULL) {
1279                 declaration = allocate_type_zero(sizeof(declaration[0]));
1280
1281                 declaration->namespc       = NAMESPACE_ENUM;
1282                 declaration->source_position = token.source_position;
1283                 declaration->symbol          = symbol;
1284         }
1285
1286         if(token.type == '{') {
1287                 if(declaration->init.is_defined) {
1288                         parser_print_error_prefix();
1289                         fprintf(stderr, "multiple definitions of enum %s\n",
1290                                 symbol->string);
1291                 }
1292                 record_declaration(declaration);
1293                 declaration->init.is_defined = 1;
1294
1295                 parse_enum_entries();
1296                 parse_attributes();
1297         }
1298
1299         return declaration;
1300 }
1301
1302 /**
1303  * if a symbol is a typedef to another type, return true
1304  */
1305 static bool is_typedef_symbol(symbol_t *symbol)
1306 {
1307         const declaration_t *const declaration =
1308                 get_declaration(symbol, NAMESPACE_NORMAL);
1309         return
1310                 declaration != NULL &&
1311                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1312 }
1313
1314 static type_t *parse_typeof(void)
1315 {
1316         eat(T___typeof__);
1317
1318         type_t *type;
1319
1320         expect('(');
1321
1322         expression_t *expression  = NULL;
1323
1324 restart:
1325         switch(token.type) {
1326         case T___extension__:
1327                 /* this can be a prefix to a typename or an expression */
1328                 /* we simply eat it now. */
1329                 do {
1330                         next_token();
1331                 } while(token.type == T___extension__);
1332                 goto restart;
1333
1334         case T_IDENTIFIER:
1335                 if(is_typedef_symbol(token.v.symbol)) {
1336                         type = parse_typename();
1337                 } else {
1338                         expression = parse_expression();
1339                         type       = expression->datatype;
1340                 }
1341                 break;
1342
1343         TYPENAME_START
1344                 type = parse_typename();
1345                 break;
1346
1347         default:
1348                 expression = parse_expression();
1349                 type       = expression->datatype;
1350                 break;
1351         }
1352
1353         expect(')');
1354
1355         typeof_type_t *typeof = allocate_type_zero(sizeof(typeof[0]));
1356         typeof->type.type     = TYPE_TYPEOF;
1357         typeof->expression    = expression;
1358         typeof->typeof_type   = type;
1359
1360         return (type_t*) typeof;
1361 }
1362
1363 typedef enum {
1364         SPECIFIER_SIGNED    = 1 << 0,
1365         SPECIFIER_UNSIGNED  = 1 << 1,
1366         SPECIFIER_LONG      = 1 << 2,
1367         SPECIFIER_INT       = 1 << 3,
1368         SPECIFIER_DOUBLE    = 1 << 4,
1369         SPECIFIER_CHAR      = 1 << 5,
1370         SPECIFIER_SHORT     = 1 << 6,
1371         SPECIFIER_LONG_LONG = 1 << 7,
1372         SPECIFIER_FLOAT     = 1 << 8,
1373         SPECIFIER_BOOL      = 1 << 9,
1374         SPECIFIER_VOID      = 1 << 10,
1375 #ifdef PROVIDE_COMPLEX
1376         SPECIFIER_COMPLEX   = 1 << 11,
1377         SPECIFIER_IMAGINARY = 1 << 12,
1378 #endif
1379 } specifiers_t;
1380
1381 static type_t *create_builtin_type(symbol_t *symbol)
1382 {
1383         builtin_type_t *type = allocate_type_zero(sizeof(type[0]));
1384         type->type.type      = TYPE_BUILTIN;
1385         type->symbol         = symbol;
1386         /* TODO... */
1387         type->real_type      = type_int;
1388
1389         return (type_t*) type;
1390 }
1391
1392 static type_t *get_typedef_type(symbol_t *symbol)
1393 {
1394         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1395         if(declaration == NULL
1396                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1397                 return NULL;
1398
1399         typedef_type_t *typedef_type = allocate_type_zero(sizeof(typedef_type[0]));
1400         typedef_type->type.type    = TYPE_TYPEDEF;
1401         typedef_type->declaration  = declaration;
1402
1403         return (type_t*) typedef_type;
1404 }
1405
1406 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1407 {
1408         type_t        *type            = NULL;
1409         unsigned       type_qualifiers = 0;
1410         unsigned       type_specifiers = 0;
1411         int            newtype         = 0;
1412
1413         while(true) {
1414                 switch(token.type) {
1415
1416                 /* storage class */
1417 #define MATCH_STORAGE_CLASS(token, class)                                \
1418                 case token:                                                      \
1419                         if(specifiers->storage_class != STORAGE_CLASS_NONE) {        \
1420                                 parse_error("multiple storage classes in declaration "   \
1421                                             "specifiers");                               \
1422                         }                                                            \
1423                         specifiers->storage_class = class;                           \
1424                         next_token();                                                \
1425                         break;
1426
1427                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1428                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1429                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1430                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1431                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1432
1433                 /* type qualifiers */
1434 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1435                 case token:                                                     \
1436                         type_qualifiers |= qualifier;                               \
1437                         next_token();                                               \
1438                         break;
1439
1440                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1441                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1442                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1443
1444                 case T___extension__:
1445                         /* TODO */
1446                         next_token();
1447                         break;
1448
1449                 /* type specifiers */
1450 #define MATCH_SPECIFIER(token, specifier, name)                         \
1451                 case token:                                                     \
1452                         next_token();                                               \
1453                         if(type_specifiers & specifier) {                           \
1454                                 parse_error("multiple " name " type specifiers given"); \
1455                         } else {                                                    \
1456                                 type_specifiers |= specifier;                           \
1457                         }                                                           \
1458                         break;
1459
1460                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
1461                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
1462                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
1463                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
1464                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
1465                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
1466                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
1467                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
1468                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
1469 #ifdef PROVIDE_COMPLEX
1470                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
1471                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
1472 #endif
1473                 case T_inline:
1474                         next_token();
1475                         specifiers->is_inline = true;
1476                         break;
1477
1478                 case T_long:
1479                         next_token();
1480                         if(type_specifiers & SPECIFIER_LONG_LONG) {
1481                                 parse_error("multiple type specifiers given");
1482                         } else if(type_specifiers & SPECIFIER_LONG) {
1483                                 type_specifiers |= SPECIFIER_LONG_LONG;
1484                         } else {
1485                                 type_specifiers |= SPECIFIER_LONG;
1486                         }
1487                         break;
1488
1489                 /* TODO: if type != NULL for the following rules should issue
1490                  * an error */
1491                 case T_struct: {
1492                         compound_type_t *compound_type
1493                                 = allocate_type_zero(sizeof(compound_type[0]));
1494                         compound_type->type.type = TYPE_COMPOUND_STRUCT;
1495                         compound_type->declaration = parse_compound_type_specifier(true);
1496
1497                         type = (type_t*) compound_type;
1498                         break;
1499                 }
1500                 case T_union: {
1501                         compound_type_t *compound_type
1502                                 = allocate_type_zero(sizeof(compound_type[0]));
1503                         compound_type->type.type = TYPE_COMPOUND_UNION;
1504                         compound_type->declaration = parse_compound_type_specifier(false);
1505
1506                         type = (type_t*) compound_type;
1507                         break;
1508                 }
1509                 case T_enum: {
1510                         enum_type_t *enum_type = allocate_type_zero(sizeof(enum_type[0]));
1511                         enum_type->type.type   = TYPE_ENUM;
1512                         enum_type->declaration = parse_enum_specifier();
1513
1514                         type = (type_t*) enum_type;
1515                         break;
1516                 }
1517                 case T___typeof__:
1518                         type = parse_typeof();
1519                         break;
1520                 case T___builtin_va_list:
1521                         type = create_builtin_type(token.v.symbol);
1522                         next_token();
1523                         break;
1524
1525                 case T___attribute__:
1526                         /* TODO */
1527                         parse_attributes();
1528                         break;
1529
1530                 case T_IDENTIFIER: {
1531                         type_t *typedef_type = get_typedef_type(token.v.symbol);
1532
1533                         if(typedef_type == NULL)
1534                                 goto finish_specifiers;
1535
1536                         next_token();
1537                         type = typedef_type;
1538                         break;
1539                 }
1540
1541                 /* function specifier */
1542                 default:
1543                         goto finish_specifiers;
1544                 }
1545         }
1546
1547 finish_specifiers:
1548
1549         if(type == NULL) {
1550                 atomic_type_type_t atomic_type;
1551
1552                 /* match valid basic types */
1553                 switch(type_specifiers) {
1554                 case SPECIFIER_VOID:
1555                         atomic_type = ATOMIC_TYPE_VOID;
1556                         break;
1557                 case SPECIFIER_CHAR:
1558                         atomic_type = ATOMIC_TYPE_CHAR;
1559                         break;
1560                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
1561                         atomic_type = ATOMIC_TYPE_SCHAR;
1562                         break;
1563                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
1564                         atomic_type = ATOMIC_TYPE_UCHAR;
1565                         break;
1566                 case SPECIFIER_SHORT:
1567                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
1568                 case SPECIFIER_SHORT | SPECIFIER_INT:
1569                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1570                         atomic_type = ATOMIC_TYPE_SHORT;
1571                         break;
1572                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
1573                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1574                         atomic_type = ATOMIC_TYPE_USHORT;
1575                         break;
1576                 case SPECIFIER_INT:
1577                 case SPECIFIER_SIGNED:
1578                 case SPECIFIER_SIGNED | SPECIFIER_INT:
1579                         atomic_type = ATOMIC_TYPE_INT;
1580                         break;
1581                 case SPECIFIER_UNSIGNED:
1582                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
1583                         atomic_type = ATOMIC_TYPE_UINT;
1584                         break;
1585                 case SPECIFIER_LONG:
1586                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
1587                 case SPECIFIER_LONG | SPECIFIER_INT:
1588                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1589                         atomic_type = ATOMIC_TYPE_LONG;
1590                         break;
1591                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
1592                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1593                         atomic_type = ATOMIC_TYPE_ULONG;
1594                         break;
1595                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1596                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1597                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
1598                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1599                         | SPECIFIER_INT:
1600                         atomic_type = ATOMIC_TYPE_LONGLONG;
1601                         break;
1602                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1603                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1604                         | SPECIFIER_INT:
1605                         atomic_type = ATOMIC_TYPE_ULONGLONG;
1606                         break;
1607                 case SPECIFIER_FLOAT:
1608                         atomic_type = ATOMIC_TYPE_FLOAT;
1609                         break;
1610                 case SPECIFIER_DOUBLE:
1611                         atomic_type = ATOMIC_TYPE_DOUBLE;
1612                         break;
1613                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
1614                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
1615                         break;
1616                 case SPECIFIER_BOOL:
1617                         atomic_type = ATOMIC_TYPE_BOOL;
1618                         break;
1619 #ifdef PROVIDE_COMPLEX
1620                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
1621                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
1622                         break;
1623                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1624                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
1625                         break;
1626                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1627                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
1628                         break;
1629                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
1630                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
1631                         break;
1632                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1633                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
1634                         break;
1635                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1636                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
1637                         break;
1638 #endif
1639                 default:
1640                         /* invalid specifier combination, give an error message */
1641                         if(type_specifiers == 0) {
1642 #ifndef STRICT_C99
1643                                 parse_warning("no type specifiers in declaration (using int)");
1644                                 atomic_type = ATOMIC_TYPE_INT;
1645                                 break;
1646 #else
1647                                 parse_error("no type specifiers given in declaration");
1648 #endif
1649                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
1650                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
1651                                 parse_error("signed and unsigned specifiers gives");
1652                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
1653                                 parse_error("only integer types can be signed or unsigned");
1654                         } else {
1655                                 parse_error("multiple datatypes in declaration");
1656                         }
1657                         atomic_type = ATOMIC_TYPE_INVALID;
1658                 }
1659
1660                 atomic_type_t *atype = allocate_type_zero(sizeof(atype[0]));
1661                 atype->type.type     = TYPE_ATOMIC;
1662                 atype->atype         = atomic_type;
1663                 newtype              = 1;
1664
1665                 type = (type_t*) atype;
1666         } else {
1667                 if(type_specifiers != 0) {
1668                         parse_error("multiple datatypes in declaration");
1669                 }
1670         }
1671
1672         type->qualifiers = (type_qualifier_t)type_qualifiers;
1673
1674         type_t *result = typehash_insert(type);
1675         if(newtype && result != (type_t*) type) {
1676                 free_type(type);
1677         }
1678
1679         specifiers->type = result;
1680 }
1681
1682 static unsigned parse_type_qualifiers(void)
1683 {
1684         unsigned type_qualifiers = TYPE_QUALIFIER_NONE;
1685
1686         while(true) {
1687                 switch(token.type) {
1688                 /* type qualifiers */
1689                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1690                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1691                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1692
1693                 default:
1694                         return type_qualifiers;
1695                 }
1696         }
1697 }
1698
1699 static void parse_identifier_list(void)
1700 {
1701         while(true) {
1702                 if(token.type != T_IDENTIFIER) {
1703                         parse_error_expected("while parsing parameter identifier list",
1704                                              T_IDENTIFIER, 0);
1705                         return;
1706                 }
1707                 next_token();
1708                 if(token.type != ',')
1709                         break;
1710                 next_token();
1711         }
1712 }
1713
1714 static declaration_t *parse_parameter(void)
1715 {
1716         declaration_specifiers_t specifiers;
1717         memset(&specifiers, 0, sizeof(specifiers));
1718
1719         parse_declaration_specifiers(&specifiers);
1720
1721         declaration_t *declaration
1722                 = parse_declarator(&specifiers, specifiers.type, true);
1723
1724         /* TODO check declaration constraints for parameters */
1725         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
1726                 parse_error("typedef not allowed in parameter list");
1727         }
1728
1729         /* Array as last part of a paramter type is just syntactic sugar.  Turn it
1730          * into a pointer */
1731         if (declaration->type->type == TYPE_ARRAY) {
1732                 const array_type_t *const arr_type =
1733                         (const array_type_t*)declaration->type;
1734                 declaration->type =
1735                         make_pointer_type(arr_type->element_type, TYPE_QUALIFIER_NONE);
1736         }
1737
1738         return declaration;
1739 }
1740
1741 static declaration_t *parse_parameters(function_type_t *type)
1742 {
1743         if(token.type == T_IDENTIFIER) {
1744                 symbol_t      *symbol = token.v.symbol;
1745                 if(!is_typedef_symbol(symbol)) {
1746                         /* TODO: K&R style C parameters */
1747                         parse_identifier_list();
1748                         return NULL;
1749                 }
1750         }
1751
1752         if(token.type == ')') {
1753                 type->unspecified_parameters = 1;
1754                 return NULL;
1755         }
1756         if(token.type == T_void && look_ahead(1)->type == ')') {
1757                 next_token();
1758                 return NULL;
1759         }
1760
1761         declaration_t        *declarations = NULL;
1762         declaration_t        *declaration;
1763         declaration_t        *last_declaration = NULL;
1764         function_parameter_t *parameter;
1765         function_parameter_t *last_parameter = NULL;
1766
1767         while(true) {
1768                 switch(token.type) {
1769                 case T_DOTDOTDOT:
1770                         next_token();
1771                         type->variadic = 1;
1772                         return declarations;
1773
1774                 case T_IDENTIFIER:
1775                 case T___extension__:
1776                 DECLARATION_START
1777                         declaration = parse_parameter();
1778
1779                         parameter       = allocate_type_zero(sizeof(parameter[0]));
1780                         parameter->type = declaration->type;
1781
1782                         if(last_parameter != NULL) {
1783                                 last_declaration->next = declaration;
1784                                 last_parameter->next   = parameter;
1785                         } else {
1786                                 type->parameters = parameter;
1787                                 declarations     = declaration;
1788                         }
1789                         last_parameter   = parameter;
1790                         last_declaration = declaration;
1791                         break;
1792
1793                 default:
1794                         return declarations;
1795                 }
1796                 if(token.type != ',')
1797                         return declarations;
1798                 next_token();
1799         }
1800 }
1801
1802 typedef enum {
1803         CONSTRUCT_INVALID,
1804         CONSTRUCT_POINTER,
1805         CONSTRUCT_FUNCTION,
1806         CONSTRUCT_ARRAY
1807 } construct_type_type_t;
1808
1809 typedef struct construct_type_t construct_type_t;
1810 struct construct_type_t {
1811         construct_type_type_t  type;
1812         construct_type_t      *next;
1813 };
1814
1815 typedef struct parsed_pointer_t parsed_pointer_t;
1816 struct parsed_pointer_t {
1817         construct_type_t  construct_type;
1818         type_qualifier_t  type_qualifiers;
1819 };
1820
1821 typedef struct construct_function_type_t construct_function_type_t;
1822 struct construct_function_type_t {
1823         construct_type_t    construct_type;
1824         function_type_t    *function_type;
1825 };
1826
1827 typedef struct parsed_array_t parsed_array_t;
1828 struct parsed_array_t {
1829         construct_type_t  construct_type;
1830         type_qualifier_t  type_qualifiers;
1831         bool              is_static;
1832         bool              is_variable;
1833         expression_t     *size;
1834 };
1835
1836 typedef struct construct_base_type_t construct_base_type_t;
1837 struct construct_base_type_t {
1838         construct_type_t  construct_type;
1839         type_t           *type;
1840 };
1841
1842 static construct_type_t *parse_pointer_declarator(void)
1843 {
1844         eat('*');
1845
1846         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
1847         memset(pointer, 0, sizeof(pointer[0]));
1848         pointer->construct_type.type = CONSTRUCT_POINTER;
1849         pointer->type_qualifiers     = parse_type_qualifiers();
1850
1851         return (construct_type_t*) pointer;
1852 }
1853
1854 static construct_type_t *parse_array_declarator(void)
1855 {
1856         eat('[');
1857
1858         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
1859         memset(array, 0, sizeof(array[0]));
1860         array->construct_type.type = CONSTRUCT_ARRAY;
1861
1862         if(token.type == T_static) {
1863                 array->is_static = true;
1864                 next_token();
1865         }
1866
1867         type_qualifier_t type_qualifiers = parse_type_qualifiers();
1868         if(type_qualifiers != 0) {
1869                 if(token.type == T_static) {
1870                         array->is_static = true;
1871                         next_token();
1872                 }
1873         }
1874         array->type_qualifiers = type_qualifiers;
1875
1876         if(token.type == '*' && look_ahead(1)->type == ']') {
1877                 array->is_variable = true;
1878                 next_token();
1879         } else if(token.type != ']') {
1880                 array->size = parse_assignment_expression();
1881         }
1882
1883         expect(']');
1884
1885         return (construct_type_t*) array;
1886 }
1887
1888 static construct_type_t *parse_function_declarator(declaration_t *declaration)
1889 {
1890         eat('(');
1891
1892         function_type_t *type = allocate_type_zero(sizeof(type[0]));
1893         type->type.type       = TYPE_FUNCTION;
1894
1895         declaration_t *parameters = parse_parameters(type);
1896         if(declaration != NULL) {
1897                 declaration->context.declarations = parameters;
1898         }
1899
1900         construct_function_type_t *construct_function_type =
1901                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
1902         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
1903         construct_function_type->construct_type.type = CONSTRUCT_FUNCTION;
1904         construct_function_type->function_type       = type;
1905
1906         expect(')');
1907
1908         return (construct_type_t*) construct_function_type;
1909 }
1910
1911 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
1912                 int may_be_abstract)
1913 {
1914         construct_type_t *result = NULL;
1915         construct_type_t *last   = NULL;
1916
1917         while(token.type == '*') {
1918                 construct_type_t *type = parse_pointer_declarator();
1919                 if(last != NULL) {
1920                         last->next = type;
1921                 } else {
1922                         result = type;
1923                 }
1924                 last = type;
1925         }
1926
1927         /* TODO: find out if this is correct */
1928         parse_attributes();
1929
1930         construct_type_t *inner_types = NULL;
1931
1932         switch(token.type) {
1933         case T_IDENTIFIER:
1934                 if(declaration == NULL) {
1935                         parse_error("no identifier expected in typename");
1936                 } else {
1937                         declaration->symbol          = token.v.symbol;
1938                         declaration->source_position = token.source_position;
1939                 }
1940                 next_token();
1941                 break;
1942         case '(':
1943                 next_token();
1944                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
1945                 expect(')');
1946                 break;
1947         default:
1948                 if(may_be_abstract)
1949                         break;
1950                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
1951                 /* avoid a loop in the outermost scope, because eat_statement doesn't
1952                  * eat '}' */
1953                 if(token.type == '}' && current_function == NULL) {
1954                         next_token();
1955                 } else {
1956                         eat_statement();
1957                 }
1958                 return NULL;
1959         }
1960
1961         while(true) {
1962                 construct_type_t *type;
1963                 switch(token.type) {
1964                 case '(':
1965                         type = parse_function_declarator(declaration);
1966                         break;
1967                 case '[':
1968                         type = parse_array_declarator();
1969                         break;
1970                 default:
1971                         goto declarator_finished;
1972                 }
1973
1974                 if(last != NULL) {
1975                         last->next = type;
1976                 } else {
1977                         result = type;
1978                 }
1979                 last = type;
1980         }
1981
1982 declarator_finished:
1983         parse_attributes();
1984
1985         if(inner_types != NULL) {
1986                 if(last != NULL) {
1987                         last->next = inner_types;
1988                 } else {
1989                         result = inner_types;
1990                 }
1991                 last = inner_types;
1992         }
1993
1994         return result;
1995 }
1996
1997 static type_t *construct_declarator_type(construct_type_t *construct_list,
1998                                          type_t *type)
1999 {
2000         construct_type_t *iter = construct_list;
2001         for( ; iter != NULL; iter = iter->next) {
2002                 parsed_pointer_t          *parsed_pointer;
2003                 parsed_array_t            *parsed_array;
2004                 construct_function_type_t *construct_function_type;
2005                 function_type_t           *function_type;
2006                 pointer_type_t            *pointer_type;
2007                 array_type_t              *array_type;
2008
2009                 switch(iter->type) {
2010                 case CONSTRUCT_INVALID:
2011                         panic("invalid type construction found");
2012                 case CONSTRUCT_FUNCTION:
2013                         construct_function_type = (construct_function_type_t*) iter;
2014                         function_type           = construct_function_type->function_type;
2015
2016                         function_type->result_type = type;
2017                         type                       = (type_t*) function_type;
2018                         break;
2019
2020                 case CONSTRUCT_POINTER:
2021                         parsed_pointer = (parsed_pointer_t*) iter;
2022                         pointer_type   = allocate_type_zero(sizeof(pointer_type[0]));
2023
2024                         pointer_type->type.type       = TYPE_POINTER;
2025                         pointer_type->points_to       = type;
2026                         pointer_type->type.qualifiers = parsed_pointer->type_qualifiers;
2027                         type                          = (type_t*) pointer_type;
2028                         break;
2029
2030                 case CONSTRUCT_ARRAY:
2031                         parsed_array  = (parsed_array_t*) iter;
2032                         array_type    = allocate_type_zero(sizeof(array_type[0]));
2033
2034                         array_type->type.type       = TYPE_ARRAY;
2035                         array_type->element_type    = type;
2036                         array_type->type.qualifiers = parsed_array->type_qualifiers;
2037                         array_type->is_static       = parsed_array->is_static;
2038                         array_type->is_variable     = parsed_array->is_variable;
2039                         array_type->size            = parsed_array->size;
2040                         type                        = (type_t*) array_type;
2041                         break;
2042                 }
2043
2044                 type_t *hashed_type = typehash_insert((type_t*) type);
2045                 if(hashed_type != type) {
2046                         free_type(type);
2047                         type = hashed_type;
2048                 }
2049         }
2050
2051         return type;
2052 }
2053
2054 static declaration_t *parse_declarator(
2055                 const declaration_specifiers_t *specifiers,
2056                 type_t *type, bool may_be_abstract)
2057 {
2058         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2059         declaration->storage_class = specifiers->storage_class;
2060         declaration->is_inline     = specifiers->is_inline;
2061
2062         construct_type_t *construct_type
2063                 = parse_inner_declarator(declaration, may_be_abstract);
2064         declaration->type = construct_declarator_type(construct_type, type);
2065
2066         if(construct_type != NULL) {
2067                 obstack_free(&temp_obst, construct_type);
2068         }
2069
2070         return declaration;
2071 }
2072
2073 static type_t *parse_abstract_declarator(type_t *base_type)
2074 {
2075         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2076
2077         type_t *result = construct_declarator_type(construct_type, base_type);
2078         if(construct_type != NULL) {
2079                 obstack_free(&temp_obst, construct_type);
2080         }
2081
2082         return result;
2083 }
2084
2085 static declaration_t *record_declaration(declaration_t *declaration)
2086 {
2087         assert(context != NULL);
2088
2089         symbol_t *symbol = declaration->symbol;
2090         if(symbol != NULL) {
2091                 declaration_t *alias = environment_push(declaration);
2092                 if(alias != declaration)
2093                         return alias;
2094         } else {
2095                 declaration->parent_context = context;
2096         }
2097
2098         if(last_declaration != NULL) {
2099                 last_declaration->next = declaration;
2100         } else {
2101                 context->declarations = declaration;
2102         }
2103         last_declaration = declaration;
2104
2105         return declaration;
2106 }
2107
2108 static void parser_error_multiple_definition(declaration_t *previous,
2109                                              declaration_t *declaration)
2110 {
2111         parser_print_error_prefix_pos(declaration->source_position);
2112         fprintf(stderr, "multiple definition of symbol '%s'\n",
2113                 declaration->symbol->string);
2114         parser_print_error_prefix_pos(previous->source_position);
2115         fprintf(stderr, "this is the location of the previous definition.\n");
2116 }
2117
2118 static void parse_init_declarators(const declaration_specifiers_t *specifiers)
2119 {
2120         while(true) {
2121                 declaration_t *ndeclaration
2122                         = parse_declarator(specifiers, specifiers->type, false);
2123
2124                 declaration_t *declaration = record_declaration(ndeclaration);
2125
2126                 type_t *orig_type = declaration->type;
2127                 type_t *type      = skip_typeref(orig_type);
2128                 if(type->type != TYPE_FUNCTION && declaration->is_inline) {
2129                         parser_print_warning_prefix_pos(declaration->source_position);
2130                         fprintf(stderr, "variable '%s' declared 'inline'\n",
2131                                 declaration->symbol->string);
2132                 }
2133
2134                 if(token.type == '=') {
2135                         next_token();
2136
2137                         /* TODO: check that this is an allowed type (no function type) */
2138
2139                         if(declaration->init.initializer != NULL) {
2140                                 parser_error_multiple_definition(declaration, ndeclaration);
2141                         }
2142
2143                         initializer_t *initializer = parse_initializer(type);
2144
2145                         if(type->type == TYPE_ARRAY && initializer != NULL) {
2146                                 assert(initializer->type == INITIALIZER_LIST);
2147
2148                                 initializer_list_t *list = (initializer_list_t*) initializer;
2149                                 array_type_t       *array_type = (array_type_t*) type;
2150
2151                                 if(array_type->size == NULL) {
2152                                         const_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
2153
2154                                         cnst->expression.type     = EXPR_CONST;
2155                                         cnst->expression.datatype = type_size_t;
2156                                         cnst->v.int_value         = list->len;
2157
2158                                         array_type->size = (expression_t*) cnst;
2159                                 }
2160                         }
2161
2162
2163                         ndeclaration->init.initializer = initializer;
2164                 } else if(token.type == '{') {
2165                         if(type->type != TYPE_FUNCTION) {
2166                                 parser_print_error_prefix();
2167                                 fprintf(stderr, "declarator '");
2168                                 print_type_ext(orig_type, declaration->symbol, NULL);
2169                                 fprintf(stderr, "' has a body but is not a function type.\n");
2170                                 eat_block();
2171                                 continue;
2172                         }
2173
2174                         if(declaration->init.statement != NULL) {
2175                                 parser_error_multiple_definition(declaration, ndeclaration);
2176                         }
2177                         if(ndeclaration != declaration) {
2178                                 memcpy(&declaration->context, &ndeclaration->context,
2179                                        sizeof(declaration->context));
2180                         }
2181
2182                         int         top          = environment_top();
2183                         context_t  *last_context = context;
2184                         set_context(&declaration->context);
2185
2186                         /* push function parameters */
2187                         declaration_t *parameter = declaration->context.declarations;
2188                         for( ; parameter != NULL; parameter = parameter->next) {
2189                                 environment_push(parameter);
2190                         }
2191
2192                         int            label_stack_top      = label_top();
2193                         declaration_t *old_current_function = current_function;
2194                         current_function                    = declaration;
2195
2196                         statement_t *statement = parse_compound_statement();
2197
2198                         assert(current_function == declaration);
2199                         current_function = old_current_function;
2200                         label_pop_to(label_stack_top);
2201
2202                         assert(context == &declaration->context);
2203                         set_context(last_context);
2204                         environment_pop_to(top);
2205
2206                         declaration->init.statement = statement;
2207                         return;
2208                 }
2209
2210                 if(token.type != ',')
2211                         break;
2212                 next_token();
2213         }
2214         expect_void(';');
2215 }
2216
2217 static void parse_struct_declarators(const declaration_specifiers_t *specifiers)
2218 {
2219         while(1) {
2220                 if(token.type == ':') {
2221                         next_token();
2222                         parse_constant_expression();
2223                         /* TODO (bitfields) */
2224                 } else {
2225                         declaration_t *declaration
2226                                 = parse_declarator(specifiers, specifiers->type, true);
2227
2228                         /* TODO: check constraints for struct declarations */
2229                         /* TODO: check for doubled fields */
2230                         record_declaration(declaration);
2231
2232                         if(token.type == ':') {
2233                                 next_token();
2234                                 parse_constant_expression();
2235                                 /* TODO (bitfields) */
2236                         }
2237                 }
2238
2239                 if(token.type != ',')
2240                         break;
2241                 next_token();
2242         }
2243         expect_void(';');
2244 }
2245
2246 static void parse_compound_type_entries(void)
2247 {
2248         eat('{');
2249
2250         while(token.type != '}' && token.type != T_EOF) {
2251                 declaration_specifiers_t specifiers;
2252                 memset(&specifiers, 0, sizeof(specifiers));
2253                 parse_declaration_specifiers(&specifiers);
2254
2255                 parse_struct_declarators(&specifiers);
2256         }
2257         if(token.type == T_EOF) {
2258                 parse_error("unexpected error while parsing struct");
2259         }
2260         next_token();
2261 }
2262
2263 static void parse_declaration(void)
2264 {
2265         source_position_t source_position = token.source_position;
2266
2267         declaration_specifiers_t specifiers;
2268         memset(&specifiers, 0, sizeof(specifiers));
2269         parse_declaration_specifiers(&specifiers);
2270
2271         if(token.type == ';') {
2272                 if (specifiers.storage_class != STORAGE_CLASS_NONE) {
2273                         parse_warning_pos(source_position,
2274                                           "useless keyword in empty declaration");
2275                 }
2276                 switch (specifiers.type->type) {
2277                         case TYPE_COMPOUND_STRUCT:
2278                         case TYPE_COMPOUND_UNION: {
2279                                 const compound_type_t *const comp_type =
2280                                         (const compound_type_t*)specifiers.type;
2281                                 if (comp_type->declaration->symbol == NULL) {
2282                                         parse_warning_pos(source_position,
2283                                                                                                                 "unnamed struct/union that defines no instances");
2284                                 }
2285                                 break;
2286                         }
2287
2288                         case TYPE_ENUM: break;
2289
2290                         default:
2291                                 parse_warning_pos(source_position, "empty declaration");
2292                                 break;
2293                 }
2294
2295                 next_token();
2296
2297                 declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2298
2299                 declaration->type            = specifiers.type;
2300                 declaration->storage_class   = specifiers.storage_class;
2301                 declaration->source_position = source_position;
2302                 record_declaration(declaration);
2303                 return;
2304         }
2305         parse_init_declarators(&specifiers);
2306 }
2307
2308 static type_t *parse_typename(void)
2309 {
2310         declaration_specifiers_t specifiers;
2311         memset(&specifiers, 0, sizeof(specifiers));
2312         parse_declaration_specifiers(&specifiers);
2313         if(specifiers.storage_class != STORAGE_CLASS_NONE) {
2314                 /* TODO: improve error message, user does probably not know what a
2315                  * storage class is...
2316                  */
2317                 parse_error("typename may not have a storage class");
2318         }
2319
2320         type_t *result = parse_abstract_declarator(specifiers.type);
2321
2322         return result;
2323 }
2324
2325
2326
2327
2328 typedef expression_t* (*parse_expression_function) (unsigned precedence);
2329 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
2330                                                           expression_t *left);
2331
2332 typedef struct expression_parser_function_t expression_parser_function_t;
2333 struct expression_parser_function_t {
2334         unsigned                         precedence;
2335         parse_expression_function        parser;
2336         unsigned                         infix_precedence;
2337         parse_expression_infix_function  infix_parser;
2338 };
2339
2340 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
2341
2342 static expression_t *make_invalid_expression(void)
2343 {
2344         expression_t *expression    = allocate_ast_zero(sizeof(expression[0]));
2345         expression->type            = EXPR_INVALID;
2346         expression->source_position = token.source_position;
2347         return expression;
2348 }
2349
2350 static expression_t *expected_expression_error(void)
2351 {
2352         parser_print_error_prefix();
2353         fprintf(stderr, "expected expression, got token ");
2354         print_token(stderr, & token);
2355         fprintf(stderr, "\n");
2356
2357         next_token();
2358
2359         return make_invalid_expression();
2360 }
2361
2362 static expression_t *parse_string_const(void)
2363 {
2364         string_literal_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
2365
2366         cnst->expression.type     = EXPR_STRING_LITERAL;
2367         cnst->expression.datatype = type_string;
2368         cnst->value               = parse_string_literals();
2369
2370         return (expression_t*) cnst;
2371 }
2372
2373 static expression_t *parse_int_const(void)
2374 {
2375         const_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
2376
2377         cnst->expression.type     = EXPR_CONST;
2378         cnst->expression.datatype = token.datatype;
2379         cnst->v.int_value         = token.v.intvalue;
2380
2381         next_token();
2382
2383         return (expression_t*) cnst;
2384 }
2385
2386 static expression_t *parse_float_const(void)
2387 {
2388         const_t *cnst = allocate_ast_zero(sizeof(cnst[0]));
2389
2390         cnst->expression.type     = EXPR_CONST;
2391         cnst->expression.datatype = token.datatype;
2392         cnst->v.float_value       = token.v.floatvalue;
2393
2394         next_token();
2395
2396         return (expression_t*) cnst;
2397 }
2398
2399 static declaration_t *create_implicit_function(symbol_t *symbol,
2400                 const source_position_t source_position)
2401 {
2402         function_type_t *function_type
2403                 = allocate_type_zero(sizeof(function_type[0]));
2404
2405         function_type->type.type              = TYPE_FUNCTION;
2406         function_type->result_type            = type_int;
2407         function_type->unspecified_parameters = true;
2408
2409         type_t *type = typehash_insert((type_t*) function_type);
2410         if(type != (type_t*) function_type) {
2411                 free_type(function_type);
2412         }
2413
2414         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2415
2416         declaration->storage_class   = STORAGE_CLASS_EXTERN;
2417         declaration->type            = type;
2418         declaration->symbol          = symbol;
2419         declaration->source_position = source_position;
2420
2421         /* prepend the implicit definition to the global context
2422          * this is safe since the symbol wasn't declared as anything else yet
2423          */
2424         assert(symbol->declaration == NULL);
2425
2426         context_t *last_context = context;
2427         context = global_context;
2428
2429         environment_push(declaration);
2430         declaration->next     = context->declarations;
2431         context->declarations = declaration;
2432
2433         context = last_context;
2434
2435         return declaration;
2436 }
2437
2438 static expression_t *parse_reference(void)
2439 {
2440         reference_expression_t *ref = allocate_ast_zero(sizeof(ref[0]));
2441
2442         ref->expression.type = EXPR_REFERENCE;
2443         ref->symbol          = token.v.symbol;
2444
2445         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
2446
2447         source_position_t source_position = token.source_position;
2448         next_token();
2449
2450         if(declaration == NULL) {
2451 #ifndef STRICT_C99
2452                 /* an implicitly defined function */
2453                 if(token.type == '(') {
2454                         parser_print_prefix_pos(token.source_position);
2455                         fprintf(stderr, "warning: implicit declaration of function '%s'\n",
2456                                 ref->symbol->string);
2457
2458                         declaration = create_implicit_function(ref->symbol,
2459                                                                source_position);
2460                 } else
2461 #endif
2462                 {
2463                         parser_print_error_prefix();
2464                         fprintf(stderr, "unknown symbol '%s' found.\n", ref->symbol->string);
2465                         return (expression_t*) ref;
2466                 }
2467         }
2468
2469         ref->declaration         = declaration;
2470         ref->expression.datatype = declaration->type;
2471
2472         return (expression_t*) ref;
2473 }
2474
2475 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
2476 {
2477         (void) expression;
2478         (void) dest_type;
2479         /* TODO check if explicit cast is allowed and issue warnings/errors */
2480 }
2481
2482 static expression_t *parse_cast(void)
2483 {
2484         unary_expression_t *cast = allocate_ast_zero(sizeof(cast[0]));
2485
2486         cast->expression.type            = EXPR_UNARY;
2487         cast->type                       = UNEXPR_CAST;
2488         cast->expression.source_position = token.source_position;
2489
2490         type_t *type  = parse_typename();
2491
2492         expect(')');
2493         expression_t *value = parse_sub_expression(20);
2494
2495         check_cast_allowed(value, type);
2496
2497         cast->expression.datatype = type;
2498         cast->value               = value;
2499
2500         return (expression_t*) cast;
2501 }
2502
2503 static expression_t *parse_statement_expression(void)
2504 {
2505         statement_expression_t *expression
2506                 = allocate_ast_zero(sizeof(expression[0]));
2507         expression->expression.type = EXPR_STATEMENT;
2508
2509         statement_t *statement = parse_compound_statement();
2510         expression->statement  = statement;
2511         if(statement == NULL) {
2512                 expect(')');
2513                 return NULL;
2514         }
2515
2516         assert(statement->type == STATEMENT_COMPOUND);
2517         compound_statement_t *compound_statement
2518                 = (compound_statement_t*) statement;
2519
2520         /* find last statement and use it's type */
2521         const statement_t *last_statement = NULL;
2522         const statement_t *iter           = compound_statement->statements;
2523         for( ; iter != NULL; iter = iter->next) {
2524                 last_statement = iter;
2525         }
2526
2527         if(last_statement->type == STATEMENT_EXPRESSION) {
2528                 const expression_statement_t *expression_statement =
2529                         (const expression_statement_t*) last_statement;
2530                 expression->expression.datatype
2531                         = expression_statement->expression->datatype;
2532         } else {
2533                 expression->expression.datatype = type_void;
2534         }
2535
2536         expect(')');
2537
2538         return (expression_t*) expression;
2539 }
2540
2541 static expression_t *parse_brace_expression(void)
2542 {
2543         eat('(');
2544
2545         switch(token.type) {
2546         case '{':
2547                 /* gcc extension: a stement expression */
2548                 return parse_statement_expression();
2549
2550         TYPE_QUALIFIERS
2551         TYPE_SPECIFIERS
2552                 return parse_cast();
2553         case T_IDENTIFIER:
2554                 if(is_typedef_symbol(token.v.symbol)) {
2555                         return parse_cast();
2556                 }
2557         }
2558
2559         expression_t *result = parse_expression();
2560         expect(')');
2561
2562         return result;
2563 }
2564
2565 static expression_t *parse_function_keyword(void)
2566 {
2567         next_token();
2568         /* TODO */
2569
2570         if (current_function == NULL) {
2571                 parse_error("'__func__' used outside of a function");
2572         }
2573
2574         string_literal_t *expression = allocate_ast_zero(sizeof(expression[0]));
2575         expression->expression.type     = EXPR_FUNCTION;
2576         expression->expression.datatype = type_string;
2577         expression->value               = "TODO: FUNCTION";
2578
2579         return (expression_t*) expression;
2580 }
2581
2582 static expression_t *parse_pretty_function_keyword(void)
2583 {
2584         eat(T___PRETTY_FUNCTION__);
2585         /* TODO */
2586
2587         string_literal_t *expression = allocate_ast_zero(sizeof(expression[0]));
2588         expression->expression.type     = EXPR_PRETTY_FUNCTION;
2589         expression->expression.datatype = type_string;
2590         expression->value               = "TODO: PRETTY FUNCTION";
2591
2592         return (expression_t*) expression;
2593 }
2594
2595 static designator_t *parse_designator(void)
2596 {
2597         designator_t *result = allocate_ast_zero(sizeof(result[0]));
2598
2599         if(token.type != T_IDENTIFIER) {
2600                 parse_error_expected("while parsing member designator",
2601                                      T_IDENTIFIER, 0);
2602                 eat_brace();
2603                 return NULL;
2604         }
2605         result->symbol = token.v.symbol;
2606         next_token();
2607
2608         designator_t *last_designator = result;
2609         while(true) {
2610                 if(token.type == '.') {
2611                         next_token();
2612                         if(token.type != T_IDENTIFIER) {
2613                                 parse_error_expected("while parsing member designator",
2614                                                      T_IDENTIFIER, 0);
2615                                 eat_brace();
2616                                 return NULL;
2617                         }
2618                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
2619                         designator->symbol       = token.v.symbol;
2620                         next_token();
2621
2622                         last_designator->next = designator;
2623                         last_designator       = designator;
2624                         continue;
2625                 }
2626                 if(token.type == '[') {
2627                         next_token();
2628                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
2629                         designator->array_access = parse_expression();
2630                         if(designator->array_access == NULL) {
2631                                 eat_brace();
2632                                 return NULL;
2633                         }
2634                         expect(']');
2635
2636                         last_designator->next = designator;
2637                         last_designator       = designator;
2638                         continue;
2639                 }
2640                 break;
2641         }
2642
2643         return result;
2644 }
2645
2646 static expression_t *parse_offsetof(void)
2647 {
2648         eat(T___builtin_offsetof);
2649
2650         offsetof_expression_t *expression
2651                 = allocate_ast_zero(sizeof(expression[0]));
2652         expression->expression.type     = EXPR_OFFSETOF;
2653         expression->expression.datatype = type_size_t;
2654
2655         expect('(');
2656         expression->type = parse_typename();
2657         expect(',');
2658         expression->designator = parse_designator();
2659         expect(')');
2660
2661         return (expression_t*) expression;
2662 }
2663
2664 static expression_t *parse_va_arg(void)
2665 {
2666         eat(T___builtin_va_arg);
2667
2668         va_arg_expression_t *expression = allocate_ast_zero(sizeof(expression[0]));
2669         expression->expression.type     = EXPR_VA_ARG;
2670
2671         expect('(');
2672         expression->arg = parse_assignment_expression();
2673         expect(',');
2674         expression->expression.datatype = parse_typename();
2675         expect(')');
2676
2677         return (expression_t*) expression;
2678 }
2679
2680 static type_t *make_function_1_type(type_t *result_type, type_t *argument_type)
2681 {
2682         function_parameter_t *parameter = allocate_type_zero(sizeof(parameter[0]));
2683         parameter->type = argument_type;
2684
2685         function_type_t *type = allocate_type_zero(sizeof(type[0]));
2686         type->type.type   = TYPE_FUNCTION;
2687         type->result_type = result_type;
2688         type->parameters  = parameter;
2689
2690         type_t *result = typehash_insert((type_t*) type);
2691         if(result != (type_t*) type) {
2692                 free_type(type);
2693         }
2694
2695         return result;
2696 }
2697
2698 static expression_t *parse_builtin_symbol(void)
2699 {
2700         builtin_symbol_expression_t *expression
2701                 = allocate_ast_zero(sizeof(expression[0]));
2702         expression->expression.type = EXPR_BUILTIN_SYMBOL;
2703
2704         expression->symbol = token.v.symbol;
2705
2706         type_t *type;
2707         switch(token.type) {
2708         case T___builtin_alloca:
2709                 type = make_function_1_type(type_void_ptr, type_size_t);
2710                 break;
2711         }
2712
2713         next_token();
2714
2715         expression->expression.datatype = type;
2716         return (expression_t*) expression;
2717 }
2718
2719 static expression_t *parse_primary_expression(void)
2720 {
2721         switch(token.type) {
2722         case T_INTEGER:
2723                 return parse_int_const();
2724         case T_FLOATINGPOINT:
2725                 return parse_float_const();
2726         case T_STRING_LITERAL:
2727                 return parse_string_const();
2728         case T_IDENTIFIER:
2729                 return parse_reference();
2730         case T___FUNCTION__:
2731         case T___func__:
2732                 return parse_function_keyword();
2733         case T___PRETTY_FUNCTION__:
2734                 return parse_pretty_function_keyword();
2735         case T___builtin_offsetof:
2736                 return parse_offsetof();
2737         case T___builtin_va_arg:
2738                 return parse_va_arg();
2739         case T___builtin_alloca:
2740         case T___builtin_expect:
2741         case T___builtin_va_start:
2742         case T___builtin_va_end:
2743                 return parse_builtin_symbol();
2744
2745         case '(':
2746                 return parse_brace_expression();
2747         }
2748
2749         parser_print_error_prefix();
2750         fprintf(stderr, "unexpected token ");
2751         print_token(stderr, &token);
2752         fprintf(stderr, "\n");
2753         eat_statement();
2754
2755         return make_invalid_expression();
2756 }
2757
2758 static expression_t *parse_array_expression(unsigned precedence,
2759                                             expression_t *array_ref)
2760 {
2761         (void) precedence;
2762
2763         eat('[');
2764
2765         expression_t *index = parse_expression();
2766
2767         array_access_expression_t *array_access
2768                 = allocate_ast_zero(sizeof(array_access[0]));
2769
2770         array_access->expression.type = EXPR_ARRAY_ACCESS;
2771         array_access->array_ref       = array_ref;
2772         array_access->index           = index;
2773
2774         type_t *type_left  = skip_typeref(array_ref->datatype);
2775         type_t *type_right = skip_typeref(index->datatype);
2776
2777         if(type_left != NULL && type_right != NULL) {
2778                 if(type_left->type == TYPE_POINTER) {
2779                         pointer_type_t *pointer           = (pointer_type_t*) type_left;
2780                         array_access->expression.datatype = pointer->points_to;
2781                 } else if(type_left->type == TYPE_ARRAY) {
2782                         array_type_t *array_type          = (array_type_t*) type_left;
2783                         array_access->expression.datatype = array_type->element_type;
2784                 } else if(type_right->type == TYPE_POINTER) {
2785                         pointer_type_t *pointer           = (pointer_type_t*) type_right;
2786                         array_access->expression.datatype = pointer->points_to;
2787                 } else if(type_right->type == TYPE_ARRAY) {
2788                         array_type_t *array_type          = (array_type_t*) type_right;
2789                         array_access->expression.datatype = array_type->element_type;
2790                 } else {
2791                         parser_print_error_prefix();
2792                         fprintf(stderr, "array access on object with non-pointer types ");
2793                         print_type_quoted(type_left);
2794                         fprintf(stderr, ", ");
2795                         print_type_quoted(type_right);
2796                         fprintf(stderr, "\n");
2797                 }
2798         }
2799
2800         if(token.type != ']') {
2801                 parse_error_expected("Problem while parsing array access", ']', 0);
2802                 return (expression_t*) array_access;
2803         }
2804         next_token();
2805
2806         return (expression_t*) array_access;
2807 }
2808
2809 static bool is_declaration_specifier(const token_t *token,
2810                                      bool only_type_specifiers)
2811 {
2812         switch(token->type) {
2813                 TYPE_SPECIFIERS
2814                         return 1;
2815                 case T_IDENTIFIER:
2816                         return is_typedef_symbol(token->v.symbol);
2817                 STORAGE_CLASSES
2818                 TYPE_QUALIFIERS
2819                         if(only_type_specifiers)
2820                                 return 0;
2821                         return 1;
2822
2823                 default:
2824                         return 0;
2825         }
2826 }
2827
2828 static expression_t *parse_sizeof(unsigned precedence)
2829 {
2830         eat(T_sizeof);
2831
2832         sizeof_expression_t *sizeof_expression
2833                 = allocate_ast_zero(sizeof(sizeof_expression[0]));
2834         sizeof_expression->expression.type     = EXPR_SIZEOF;
2835         sizeof_expression->expression.datatype = type_size_t;
2836
2837         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
2838                 next_token();
2839                 sizeof_expression->type = parse_typename();
2840                 expect(')');
2841         } else {
2842                 expression_t *expression           = parse_sub_expression(precedence);
2843                 sizeof_expression->type            = expression->datatype;
2844                 sizeof_expression->size_expression = expression;
2845         }
2846
2847         return (expression_t*) sizeof_expression;
2848 }
2849
2850 static expression_t *parse_select_expression(unsigned precedence,
2851                                              expression_t *compound)
2852 {
2853         (void) precedence;
2854         assert(token.type == '.' || token.type == T_MINUSGREATER);
2855
2856         bool is_pointer = (token.type == T_MINUSGREATER);
2857         next_token();
2858
2859         select_expression_t *select = allocate_ast_zero(sizeof(select[0]));
2860
2861         select->expression.type = EXPR_SELECT;
2862         select->compound        = compound;
2863
2864         if(token.type != T_IDENTIFIER) {
2865                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
2866                 return (expression_t*) select;
2867         }
2868         symbol_t *symbol = token.v.symbol;
2869         select->symbol   = symbol;
2870         next_token();
2871
2872         type_t *orig_type = compound->datatype;
2873         if(orig_type == NULL)
2874                 return make_invalid_expression();
2875
2876         type_t *type = skip_typeref(orig_type);
2877
2878         type_t *type_left = type;
2879         if(is_pointer) {
2880                 if(type->type != TYPE_POINTER) {
2881                         parser_print_error_prefix();
2882                         fprintf(stderr, "left hand side of '->' is not a pointer, but ");
2883                         print_type_quoted(orig_type);
2884                         fputc('\n', stderr);
2885                         return make_invalid_expression();
2886                 }
2887                 pointer_type_t *pointer_type = (pointer_type_t*) type;
2888                 type_left                    = pointer_type->points_to;
2889         }
2890         type_left = skip_typeref(type_left);
2891
2892         if(type_left->type != TYPE_COMPOUND_STRUCT
2893                         && type_left->type != TYPE_COMPOUND_UNION) {
2894                 parser_print_error_prefix();
2895                 fprintf(stderr, "request for member '%s' in something not a struct or "
2896                         "union, but ", symbol->string);
2897                 print_type_quoted(type_left);
2898                 fputc('\n', stderr);
2899                 return make_invalid_expression();
2900         }
2901
2902         compound_type_t *compound_type = (compound_type_t*) type_left;
2903         declaration_t   *declaration   = compound_type->declaration;
2904
2905         if(!declaration->init.is_defined) {
2906                 parser_print_error_prefix();
2907                 fprintf(stderr, "request for member '%s' of incomplete type ",
2908                         symbol->string);
2909                 print_type_quoted(type_left);
2910                 fputc('\n', stderr);
2911                 return make_invalid_expression();
2912         }
2913
2914         declaration_t *iter = declaration->context.declarations;
2915         for( ; iter != NULL; iter = iter->next) {
2916                 if(iter->symbol == symbol) {
2917                         break;
2918                 }
2919         }
2920         if(iter == NULL) {
2921                 parser_print_error_prefix();
2922                 print_type_quoted(type_left);
2923                 fprintf(stderr, " has no member named '%s'\n", symbol->string);
2924                 return make_invalid_expression();
2925         }
2926
2927         select->compound_entry      = iter;
2928         select->expression.datatype = iter->type;
2929         return (expression_t*) select;
2930 }
2931
2932 static expression_t *parse_call_expression(unsigned precedence,
2933                                            expression_t *expression)
2934 {
2935         (void) precedence;
2936         call_expression_t *call = allocate_ast_zero(sizeof(call[0]));
2937         call->expression.type   = EXPR_CALL;
2938         call->function          = expression;
2939
2940         function_type_t *function_type;
2941         type_t          *type = expression->datatype;
2942         if (type->type == TYPE_FUNCTION) {
2943                 function_type             = (function_type_t*) type;
2944                 call->expression.datatype = function_type->result_type;
2945         } else if (type->type == TYPE_POINTER &&
2946                    ((pointer_type_t*)type)->points_to->type == TYPE_FUNCTION) {
2947                 pointer_type_t *const ptr_type = (pointer_type_t*)type;
2948                 function_type                  = (function_type_t*)ptr_type->points_to;
2949                 call->expression.datatype      = function_type->result_type;
2950         } else {
2951                 parser_print_error_prefix();
2952                 fputs("called object '", stderr);
2953                 print_expression(expression);
2954                 fputs("' (type ", stderr);
2955                 print_type_quoted(type);
2956                 fputs(") is not a function\n", stderr);
2957
2958                 function_type             = NULL;
2959                 call->expression.datatype = NULL;
2960         }
2961
2962         /* parse arguments */
2963         eat('(');
2964
2965         if(token.type != ')') {
2966                 call_argument_t *last_argument = NULL;
2967
2968                 while(true) {
2969                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
2970
2971                         argument->expression = parse_assignment_expression();
2972                         if(last_argument == NULL) {
2973                                 call->arguments = argument;
2974                         } else {
2975                                 last_argument->next = argument;
2976                         }
2977                         last_argument = argument;
2978
2979                         if(token.type != ',')
2980                                 break;
2981                         next_token();
2982                 }
2983         }
2984         expect(')');
2985
2986         if(function_type != NULL) {
2987                 function_parameter_t *parameter = function_type->parameters;
2988                 call_argument_t      *argument  = call->arguments;
2989                 for( ; parameter != NULL && argument != NULL;
2990                                 parameter = parameter->next, argument = argument->next) {
2991                         type_t *expected_type = parameter->type;
2992                         /* TODO report context in error messages */
2993                         argument->expression = create_implicit_cast(argument->expression,
2994                                                                     expected_type);
2995                 }
2996                 /* too few parameters */
2997                 if(parameter != NULL) {
2998                         parser_print_error_prefix();
2999                         fprintf(stderr, "too few arguments to function '");
3000                         print_expression(expression);
3001                         fprintf(stderr, "'\n");
3002                 } else if(argument != NULL) {
3003                         /* too many parameters */
3004                         if(!function_type->variadic
3005                                         && !function_type->unspecified_parameters) {
3006                                 parser_print_error_prefix();
3007                                 fprintf(stderr, "too many arguments to function '");
3008                                 print_expression(expression);
3009                                 fprintf(stderr, "'\n");
3010                         } else {
3011                                 /* do default promotion */
3012                                 for( ; argument != NULL; argument = argument->next) {
3013                                         type_t *type = argument->expression->datatype;
3014
3015                                         if(type == NULL)
3016                                                 continue;
3017
3018                                         if(is_type_integer(type)) {
3019                                                 type = promote_integer(type);
3020                                         } else if(type == type_float) {
3021                                                 type = type_double;
3022                                         }
3023                                         argument->expression
3024                                                 = create_implicit_cast(argument->expression, type);
3025                                 }
3026                         }
3027                 }
3028         }
3029
3030         return (expression_t*) call;
3031 }
3032
3033 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
3034
3035 static expression_t *parse_conditional_expression(unsigned precedence,
3036                                                   expression_t *expression)
3037 {
3038         eat('?');
3039
3040         conditional_expression_t *conditional
3041                 = allocate_ast_zero(sizeof(conditional[0]));
3042         conditional->expression.type = EXPR_CONDITIONAL;
3043         conditional->condition       = expression;
3044
3045         /* 6.5.15.2 */
3046         type_t *condition_type_orig = conditional->condition->datatype;
3047         if(condition_type_orig != NULL) {
3048                 type_t *condition_type      = skip_typeref(condition_type_orig);
3049                 if(condition_type != NULL && !is_type_scalar(condition_type)) {
3050                         type_error("expected a scalar type", expression->source_position,
3051                                            condition_type_orig);
3052                 }
3053         }
3054
3055         expression_t *const t_expr = parse_expression();
3056         conditional->true_expression = t_expr;
3057         expect(':');
3058         expression_t *const f_expr = parse_sub_expression(precedence);
3059         conditional->false_expression = f_expr;
3060
3061         type_t *const true_type  = t_expr->datatype;
3062         if(true_type == NULL)
3063                 return (expression_t*) conditional;
3064         type_t *const false_type = f_expr->datatype;
3065         if(false_type == NULL)
3066                 return (expression_t*) conditional;
3067
3068         type_t *const skipped_true_type  = skip_typeref(true_type);
3069         type_t *const skipped_false_type = skip_typeref(false_type);
3070
3071         /* 6.5.15.3 */
3072         if (skipped_true_type == skipped_false_type) {
3073                 conditional->expression.datatype = skipped_true_type;
3074         } else if (is_type_arithmetic(skipped_true_type) &&
3075                    is_type_arithmetic(skipped_false_type)) {
3076                 type_t *const result = semantic_arithmetic(skipped_true_type,
3077                                                            skipped_false_type);
3078                 conditional->true_expression  = create_implicit_cast(t_expr, result);
3079                 conditional->false_expression = create_implicit_cast(f_expr, result);
3080                 conditional->expression.datatype = result;
3081         } else if (skipped_true_type->type == TYPE_POINTER &&
3082                    skipped_false_type->type == TYPE_POINTER &&
3083                           true /* TODO compatible points_to types */) {
3084                 /* TODO */
3085         } else if(/* (is_null_ptr_const(skipped_true_type) &&
3086                       skipped_false_type->type == TYPE_POINTER)
3087                || (is_null_ptr_const(skipped_false_type) &&
3088                    skipped_true_type->type == TYPE_POINTER) TODO*/ false) {
3089                 /* TODO */
3090         } else if(/* 1 is pointer to object type, other is void* */ false) {
3091                 /* TODO */
3092         } else {
3093                 type_error_incompatible("while parsing conditional",
3094                                         expression->source_position, true_type,
3095                                         skipped_false_type);
3096         }
3097
3098         return (expression_t*) conditional;
3099 }
3100
3101 static expression_t *parse_extension(unsigned precedence)
3102 {
3103         eat(T___extension__);
3104
3105         /* TODO enable extensions */
3106
3107         return parse_sub_expression(precedence);
3108 }
3109
3110 static expression_t *parse_builtin_classify_type(const unsigned precedence)
3111 {
3112         eat(T___builtin_classify_type);
3113
3114         classify_type_expression_t *const classify_type_expr =
3115                 allocate_ast_zero(sizeof(classify_type_expr[0]));
3116         classify_type_expr->expression.type     = EXPR_CLASSIFY_TYPE;
3117         classify_type_expr->expression.datatype = type_int;
3118
3119         expect('(');
3120         expression_t *const expression = parse_sub_expression(precedence);
3121         expect(')');
3122         classify_type_expr->type_expression = expression;
3123
3124         return (expression_t*)classify_type_expr;
3125 }
3126
3127 static void semantic_incdec(unary_expression_t *expression)
3128 {
3129         type_t *orig_type = expression->value->datatype;
3130         if(orig_type == NULL)
3131                 return;
3132
3133         type_t *type = skip_typeref(orig_type);
3134         if(!is_type_arithmetic(type) && type->type != TYPE_POINTER) {
3135                 /* TODO: improve error message */
3136                 parser_print_error_prefix();
3137                 fprintf(stderr, "operation needs an arithmetic or pointer type\n");
3138                 return;
3139         }
3140
3141         expression->expression.datatype = orig_type;
3142 }
3143
3144 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
3145 {
3146         type_t *orig_type = expression->value->datatype;
3147         if(orig_type == NULL)
3148                 return;
3149
3150         type_t *type = skip_typeref(orig_type);
3151         if(!is_type_arithmetic(type)) {
3152                 /* TODO: improve error message */
3153                 parser_print_error_prefix();
3154                 fprintf(stderr, "operation needs an arithmetic type\n");
3155                 return;
3156         }
3157
3158         expression->expression.datatype = orig_type;
3159 }
3160
3161 static void semantic_unexpr_scalar(unary_expression_t *expression)
3162 {
3163         type_t *orig_type = expression->value->datatype;
3164         if(orig_type == NULL)
3165                 return;
3166
3167         type_t *type = skip_typeref(orig_type);
3168         if (!is_type_scalar(type)) {
3169                 parse_error("operand of ! must be of scalar type\n");
3170                 return;
3171         }
3172
3173         expression->expression.datatype = orig_type;
3174 }
3175
3176 static void semantic_unexpr_integer(unary_expression_t *expression)
3177 {
3178         type_t *orig_type = expression->value->datatype;
3179         if(orig_type == NULL)
3180                 return;
3181
3182         type_t *type = skip_typeref(orig_type);
3183         if (!is_type_integer(type)) {
3184                 parse_error("operand of ~ must be of integer type\n");
3185                 return;
3186         }
3187
3188         expression->expression.datatype = orig_type;
3189 }
3190
3191 static void semantic_dereference(unary_expression_t *expression)
3192 {
3193         type_t *orig_type = expression->value->datatype;
3194         if(orig_type == NULL)
3195                 return;
3196
3197         type_t *type = skip_typeref(orig_type);
3198         switch (type->type) {
3199                 case TYPE_ARRAY: {
3200                         array_type_t *const array_type  = (array_type_t*)type;
3201                         expression->expression.datatype = array_type->element_type;
3202                         break;
3203                 }
3204
3205                 case TYPE_POINTER: {
3206                         pointer_type_t *pointer_type    = (pointer_type_t*)type;
3207                         expression->expression.datatype = pointer_type->points_to;
3208                         break;
3209                 }
3210
3211                 default:
3212                         parser_print_error_prefix();
3213                         fputs("'Unary *' needs pointer or arrray type, but type ", stderr);
3214                         print_type_quoted(orig_type);
3215                         fputs(" given.\n", stderr);
3216                         return;
3217         }
3218 }
3219
3220 static void semantic_take_addr(unary_expression_t *expression)
3221 {
3222         type_t *orig_type = expression->value->datatype;
3223         if(orig_type == NULL)
3224                 return;
3225
3226         expression_t *value = expression->value;
3227         if(value->type == EXPR_REFERENCE) {
3228                 reference_expression_t *reference   = (reference_expression_t*) value;
3229                 declaration_t          *declaration = reference->declaration;
3230                 if(declaration != NULL) {
3231                         declaration->address_taken = 1;
3232                 }
3233         }
3234
3235         expression->expression.datatype = make_pointer_type(orig_type, 0);
3236 }
3237
3238 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
3239 static expression_t *parse_##unexpression_type(unsigned precedence)            \
3240 {                                                                              \
3241         eat(token_type);                                                           \
3242                                                                                \
3243         unary_expression_t *unary_expression                                       \
3244                 = allocate_ast_zero(sizeof(unary_expression[0]));                      \
3245         unary_expression->expression.type     = EXPR_UNARY;                        \
3246         unary_expression->type                = unexpression_type;                 \
3247         unary_expression->value               = parse_sub_expression(precedence);  \
3248                                                                                    \
3249         sfunc(unary_expression);                                                   \
3250                                                                                \
3251         return (expression_t*) unary_expression;                                   \
3252 }
3253
3254 CREATE_UNARY_EXPRESSION_PARSER('-', UNEXPR_NEGATE, semantic_unexpr_arithmetic)
3255 CREATE_UNARY_EXPRESSION_PARSER('+', UNEXPR_PLUS,   semantic_unexpr_arithmetic)
3256 CREATE_UNARY_EXPRESSION_PARSER('!', UNEXPR_NOT,    semantic_unexpr_scalar)
3257 CREATE_UNARY_EXPRESSION_PARSER('*', UNEXPR_DEREFERENCE, semantic_dereference)
3258 CREATE_UNARY_EXPRESSION_PARSER('&', UNEXPR_TAKE_ADDRESS, semantic_take_addr)
3259 CREATE_UNARY_EXPRESSION_PARSER('~', UNEXPR_BITWISE_NEGATE,
3260                                semantic_unexpr_integer)
3261 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_PREFIX_INCREMENT,
3262                                semantic_incdec)
3263 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_PREFIX_DECREMENT,
3264                                semantic_incdec)
3265
3266 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
3267                                                sfunc)                         \
3268 static expression_t *parse_##unexpression_type(unsigned precedence,           \
3269                                                expression_t *left)            \
3270 {                                                                             \
3271         (void) precedence;                                                        \
3272         eat(token_type);                                                          \
3273                                                                               \
3274         unary_expression_t *unary_expression                                      \
3275                 = allocate_ast_zero(sizeof(unary_expression[0]));                     \
3276         unary_expression->expression.type     = EXPR_UNARY;                       \
3277         unary_expression->type                = unexpression_type;                \
3278         unary_expression->value               = left;                             \
3279                                                                                   \
3280         sfunc(unary_expression);                                                  \
3281                                                                               \
3282         return (expression_t*) unary_expression;                                  \
3283 }
3284
3285 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,   UNEXPR_POSTFIX_INCREMENT,
3286                                        semantic_incdec)
3287 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS, UNEXPR_POSTFIX_DECREMENT,
3288                                        semantic_incdec)
3289
3290 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
3291 {
3292         /* TODO: handle complex + imaginary types */
3293
3294         /* § 6.3.1.8 Usual arithmetic conversions */
3295         if(type_left == type_long_double || type_right == type_long_double) {
3296                 return type_long_double;
3297         } else if(type_left == type_double || type_right == type_double) {
3298                 return type_double;
3299         } else if(type_left == type_float || type_right == type_float) {
3300                 return type_float;
3301         }
3302
3303         type_right = promote_integer(type_right);
3304         type_left  = promote_integer(type_left);
3305
3306         if(type_left == type_right)
3307                 return type_left;
3308
3309         bool signed_left  = is_type_signed(type_left);
3310         bool signed_right = is_type_signed(type_right);
3311         if(get_rank(type_left) < get_rank(type_right)) {
3312                 if(signed_left == signed_right || !signed_right) {
3313                         return type_right;
3314                 } else {
3315                         return type_left;
3316                 }
3317         } else {
3318                 if(signed_left == signed_right || !signed_left) {
3319                         return type_left;
3320                 } else {
3321                         return type_right;
3322                 }
3323         }
3324 }
3325
3326 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
3327 {
3328         expression_t *left       = expression->left;
3329         expression_t *right      = expression->right;
3330         type_t       *orig_type_left  = left->datatype;
3331         type_t       *orig_type_right = right->datatype;
3332
3333         if(orig_type_left == NULL || orig_type_right == NULL)
3334                 return;
3335
3336         type_t *type_left  = skip_typeref(orig_type_left);
3337         type_t *type_right = skip_typeref(orig_type_right);
3338
3339         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
3340                 /* TODO: improve error message */
3341                 parser_print_error_prefix();
3342                 fprintf(stderr, "operation needs arithmetic types\n");
3343                 return;
3344         }
3345
3346         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
3347         expression->left  = create_implicit_cast(left, arithmetic_type);
3348         expression->right = create_implicit_cast(right, arithmetic_type);
3349         expression->expression.datatype = arithmetic_type;
3350 }
3351
3352 static void semantic_shift_op(binary_expression_t *expression)
3353 {
3354         expression_t *left       = expression->left;
3355         expression_t *right      = expression->right;
3356         type_t       *orig_type_left  = left->datatype;
3357         type_t       *orig_type_right = right->datatype;
3358
3359         if(orig_type_left == NULL || orig_type_right == NULL)
3360                 return;
3361
3362         type_t *type_left  = skip_typeref(orig_type_left);
3363         type_t *type_right = skip_typeref(orig_type_right);
3364
3365         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
3366                 /* TODO: improve error message */
3367                 parser_print_error_prefix();
3368                 fprintf(stderr, "operation needs integer types\n");
3369                 return;
3370         }
3371
3372         type_left  = promote_integer(type_left);
3373         type_right = promote_integer(type_right);
3374
3375         expression->left  = create_implicit_cast(left, type_left);
3376         expression->right = create_implicit_cast(right, type_right);
3377         expression->expression.datatype = type_left;
3378 }
3379
3380 static void semantic_add(binary_expression_t *expression)
3381 {
3382         expression_t *left            = expression->left;
3383         expression_t *right           = expression->right;
3384         type_t       *orig_type_left  = left->datatype;
3385         type_t       *orig_type_right = right->datatype;
3386
3387         if(orig_type_left == NULL || orig_type_right == NULL)
3388                 return;
3389
3390         type_t *type_left  = skip_typeref(orig_type_left);
3391         type_t *type_right = skip_typeref(orig_type_right);
3392
3393         /* § 5.6.5 */
3394         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
3395                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
3396                 expression->left  = create_implicit_cast(left, arithmetic_type);
3397                 expression->right = create_implicit_cast(right, arithmetic_type);
3398                 expression->expression.datatype = arithmetic_type;
3399                 return;
3400         } else if(type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
3401                 expression->expression.datatype = type_left;
3402         } else if(type_right->type == TYPE_POINTER && is_type_integer(type_left)) {
3403                 expression->expression.datatype = type_right;
3404         } else if (type_left->type == TYPE_ARRAY && is_type_integer(type_right)) {
3405                 const array_type_t *const arr_type = (const array_type_t*)type_left;
3406                 expression->expression.datatype =
3407                   make_pointer_type(arr_type->element_type, TYPE_QUALIFIER_NONE);
3408         } else if (type_right->type == TYPE_ARRAY && is_type_integer(type_left)) {
3409                 const array_type_t *const arr_type = (const array_type_t*)type_right;
3410                 expression->expression.datatype =
3411                         make_pointer_type(arr_type->element_type, TYPE_QUALIFIER_NONE);
3412         } else {
3413                 parser_print_error_prefix();
3414                 fprintf(stderr, "invalid operands to binary + (");
3415                 print_type_quoted(orig_type_left);
3416                 fprintf(stderr, ", ");
3417                 print_type_quoted(orig_type_right);
3418                 fprintf(stderr, ")\n");
3419         }
3420 }
3421
3422 static void semantic_sub(binary_expression_t *expression)
3423 {
3424         expression_t *left            = expression->left;
3425         expression_t *right           = expression->right;
3426         type_t       *orig_type_left  = left->datatype;
3427         type_t       *orig_type_right = right->datatype;
3428
3429         if(orig_type_left == NULL || orig_type_right == NULL)
3430                 return;
3431
3432         type_t       *type_left       = skip_typeref(orig_type_left);
3433         type_t       *type_right      = skip_typeref(orig_type_right);
3434
3435         /* § 5.6.5 */
3436         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
3437                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
3438                 expression->left  = create_implicit_cast(left, arithmetic_type);
3439                 expression->right = create_implicit_cast(right, arithmetic_type);
3440                 expression->expression.datatype = arithmetic_type;
3441                 return;
3442         } else if(type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
3443                 expression->expression.datatype = type_left;
3444         } else if(type_left->type == TYPE_POINTER &&
3445                         type_right->type == TYPE_POINTER) {
3446                 if(!pointers_compatible(type_left, type_right)) {
3447                         parser_print_error_prefix();
3448                         fprintf(stderr, "pointers to incompatible objects to binary - (");
3449                         print_type_quoted(orig_type_left);
3450                         fprintf(stderr, ", ");
3451                         print_type_quoted(orig_type_right);
3452                         fprintf(stderr, ")\n");
3453                 } else {
3454                         expression->expression.datatype = type_ptrdiff_t;
3455                 }
3456         } else {
3457                 parser_print_error_prefix();
3458                 fprintf(stderr, "invalid operands to binary - (");
3459                 print_type_quoted(orig_type_left);
3460                 fprintf(stderr, ", ");
3461                 print_type_quoted(orig_type_right);
3462                 fprintf(stderr, ")\n");
3463         }
3464 }
3465
3466 static void semantic_comparison(binary_expression_t *expression)
3467 {
3468         expression_t *left            = expression->left;
3469         expression_t *right           = expression->right;
3470         type_t       *orig_type_left  = left->datatype;
3471         type_t       *orig_type_right = right->datatype;
3472
3473         if(orig_type_left == NULL || orig_type_right == NULL)
3474                 return;
3475
3476         type_t *type_left  = skip_typeref(orig_type_left);
3477         type_t *type_right = skip_typeref(orig_type_right);
3478
3479         /* TODO non-arithmetic types */
3480         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
3481                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
3482                 expression->left  = create_implicit_cast(left, arithmetic_type);
3483                 expression->right = create_implicit_cast(right, arithmetic_type);
3484                 expression->expression.datatype = arithmetic_type;
3485         } else if (type_left->type  == TYPE_POINTER &&
3486                    type_right->type == TYPE_POINTER) {
3487                 /* TODO check compatibility */
3488         } else if (type_left->type == TYPE_POINTER) {
3489                 expression->right = create_implicit_cast(right, type_left);
3490         } else if (type_right->type == TYPE_POINTER) {
3491                 expression->left = create_implicit_cast(left, type_right);
3492         } else {
3493                 type_error_incompatible("invalid operands in comparison",
3494                                         token.source_position, type_left, type_right);
3495         }
3496         expression->expression.datatype = type_int;
3497 }
3498
3499 static void semantic_arithmetic_assign(binary_expression_t *expression)
3500 {
3501         expression_t *left            = expression->left;
3502         expression_t *right           = expression->right;
3503         type_t       *orig_type_left  = left->datatype;
3504         type_t       *orig_type_right = right->datatype;
3505
3506         if(orig_type_left == NULL || orig_type_right == NULL)
3507                 return;
3508
3509         type_t *type_left  = skip_typeref(orig_type_left);
3510         type_t *type_right = skip_typeref(orig_type_right);
3511
3512         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
3513                 /* TODO: improve error message */
3514                 parser_print_error_prefix();
3515                 fprintf(stderr, "operation needs arithmetic types\n");
3516                 return;
3517         }
3518
3519         /* combined instructions are tricky. We can't create an implicit cast on
3520          * the left side, because we need the uncasted form for the store.
3521          * The ast2firm pass has to know that left_type must be right_type
3522          * for the arithmeitc operation and create a cast by itself */
3523         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
3524         expression->right       = create_implicit_cast(right, arithmetic_type);
3525         expression->expression.datatype = type_left;
3526 }
3527
3528 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
3529 {
3530         expression_t *left            = expression->left;
3531         expression_t *right           = expression->right;
3532         type_t       *orig_type_left  = left->datatype;
3533         type_t       *orig_type_right = right->datatype;
3534
3535         if(orig_type_left == NULL || orig_type_right == NULL)
3536                 return;
3537
3538         type_t *type_left  = skip_typeref(orig_type_left);
3539         type_t *type_right = skip_typeref(orig_type_right);
3540
3541         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
3542                 /* combined instructions are tricky. We can't create an implicit cast on
3543                  * the left side, because we need the uncasted form for the store.
3544                  * The ast2firm pass has to know that left_type must be right_type
3545                  * for the arithmeitc operation and create a cast by itself */
3546                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
3547                 expression->right = create_implicit_cast(right, arithmetic_type);
3548                 expression->expression.datatype = type_left;
3549         } else if (type_left->type == TYPE_POINTER && is_type_integer(type_right)) {
3550                 expression->expression.datatype = type_left;
3551         } else {
3552                 parser_print_error_prefix();
3553                 fputs("Incompatible types ", stderr);
3554                 print_type_quoted(orig_type_left);
3555                 fputs(" and ", stderr);
3556                 print_type_quoted(orig_type_right);
3557                 fputs(" in assignment\n", stderr);
3558                 return;
3559         }
3560 }
3561
3562 static void semantic_logical_op(binary_expression_t *expression)
3563 {
3564         expression_t *left            = expression->left;
3565         expression_t *right           = expression->right;
3566         type_t       *orig_type_left  = left->datatype;
3567         type_t       *orig_type_right = right->datatype;
3568
3569         if(orig_type_left == NULL || orig_type_right == NULL)
3570                 return;
3571
3572         type_t *type_left  = skip_typeref(orig_type_left);
3573         type_t *type_right = skip_typeref(orig_type_right);
3574
3575         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
3576                 /* TODO: improve error message */
3577                 parser_print_error_prefix();
3578                 fprintf(stderr, "operation needs scalar types\n");
3579                 return;
3580         }
3581
3582         expression->expression.datatype = type_int;
3583 }
3584
3585 static void semantic_binexpr_assign(binary_expression_t *expression)
3586 {
3587         expression_t *left       = expression->left;
3588         type_t       *type_left  = left->datatype;
3589
3590         if(type_left == NULL)
3591                 return;
3592
3593         if (type_left->type == TYPE_ARRAY) {
3594                 parse_error("Cannot assign to arrays.");
3595         } else if (type_left != NULL) {
3596                 semantic_assign(type_left, &expression->right, "assignment");
3597         }
3598
3599         expression->expression.datatype = type_left;
3600 }
3601
3602 static void semantic_comma(binary_expression_t *expression)
3603 {
3604         expression->expression.datatype = expression->right->datatype;
3605 }
3606
3607 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr) \
3608 static expression_t *parse_##binexpression_type(unsigned precedence,     \
3609                                                 expression_t *left)      \
3610 {                                                                        \
3611         eat(token_type);                                                     \
3612                                                                          \
3613         expression_t *right = parse_sub_expression(precedence + lr);         \
3614                                                                          \
3615         binary_expression_t *binexpr                                         \
3616                 = allocate_ast_zero(sizeof(binexpr[0]));                         \
3617         binexpr->expression.type     = EXPR_BINARY;                          \
3618         binexpr->type                = binexpression_type;                   \
3619         binexpr->left                = left;                                 \
3620         binexpr->right               = right;                                \
3621         sfunc(binexpr);                                                      \
3622                                                                          \
3623         return (expression_t*) binexpr;                                      \
3624 }
3625
3626 CREATE_BINEXPR_PARSER(',', BINEXPR_COMMA,          semantic_comma, 1)
3627 CREATE_BINEXPR_PARSER('*', BINEXPR_MUL,            semantic_binexpr_arithmetic, 1)
3628 CREATE_BINEXPR_PARSER('/', BINEXPR_DIV,            semantic_binexpr_arithmetic, 1)
3629 CREATE_BINEXPR_PARSER('%', BINEXPR_MOD,            semantic_binexpr_arithmetic, 1)
3630 CREATE_BINEXPR_PARSER('+', BINEXPR_ADD,            semantic_add, 1)
3631 CREATE_BINEXPR_PARSER('-', BINEXPR_SUB,            semantic_sub, 1)
3632 CREATE_BINEXPR_PARSER('<', BINEXPR_LESS,           semantic_comparison, 1)
3633 CREATE_BINEXPR_PARSER('>', BINEXPR_GREATER,        semantic_comparison, 1)
3634 CREATE_BINEXPR_PARSER('=', BINEXPR_ASSIGN,         semantic_binexpr_assign, 0)
3635 CREATE_BINEXPR_PARSER(T_EQUALEQUAL, BINEXPR_EQUAL, semantic_comparison, 1)
3636 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, BINEXPR_NOTEQUAL,
3637                       semantic_comparison, 1)
3638 CREATE_BINEXPR_PARSER(T_LESSEQUAL, BINEXPR_LESSEQUAL, semantic_comparison, 1)
3639 CREATE_BINEXPR_PARSER(T_GREATEREQUAL, BINEXPR_GREATEREQUAL,
3640                       semantic_comparison, 1)
3641 CREATE_BINEXPR_PARSER('&', BINEXPR_BITWISE_AND,    semantic_binexpr_arithmetic, 1)
3642 CREATE_BINEXPR_PARSER('|', BINEXPR_BITWISE_OR,     semantic_binexpr_arithmetic, 1)
3643 CREATE_BINEXPR_PARSER('^', BINEXPR_BITWISE_XOR,    semantic_binexpr_arithmetic, 1)
3644 CREATE_BINEXPR_PARSER(T_ANDAND, BINEXPR_LOGICAL_AND,  semantic_logical_op, 1)
3645 CREATE_BINEXPR_PARSER(T_PIPEPIPE, BINEXPR_LOGICAL_OR, semantic_logical_op, 1)
3646 /* TODO shift has a bit special semantic */
3647 CREATE_BINEXPR_PARSER(T_LESSLESS, BINEXPR_SHIFTLEFT,
3648                       semantic_shift_op, 1)
3649 CREATE_BINEXPR_PARSER(T_GREATERGREATER, BINEXPR_SHIFTRIGHT,
3650                       semantic_shift_op, 1)
3651 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, BINEXPR_ADD_ASSIGN,
3652                       semantic_arithmetic_addsubb_assign, 0)
3653 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, BINEXPR_SUB_ASSIGN,
3654                       semantic_arithmetic_addsubb_assign, 0)
3655 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, BINEXPR_MUL_ASSIGN,
3656                       semantic_arithmetic_assign, 0)
3657 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, BINEXPR_DIV_ASSIGN,
3658                       semantic_arithmetic_assign, 0)
3659 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, BINEXPR_MOD_ASSIGN,
3660                       semantic_arithmetic_assign, 0)
3661 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, BINEXPR_SHIFTLEFT_ASSIGN,
3662                       semantic_arithmetic_assign, 0)
3663 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, BINEXPR_SHIFTRIGHT_ASSIGN,
3664                       semantic_arithmetic_assign, 0)
3665 CREATE_BINEXPR_PARSER(T_ANDEQUAL, BINEXPR_BITWISE_AND_ASSIGN,
3666                       semantic_arithmetic_assign, 0)
3667 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, BINEXPR_BITWISE_OR_ASSIGN,
3668                       semantic_arithmetic_assign, 0)
3669 CREATE_BINEXPR_PARSER(T_CARETEQUAL, BINEXPR_BITWISE_XOR_ASSIGN,
3670                       semantic_arithmetic_assign, 0)
3671
3672 static expression_t *parse_sub_expression(unsigned precedence)
3673 {
3674         if(token.type < 0) {
3675                 return expected_expression_error();
3676         }
3677
3678         expression_parser_function_t *parser
3679                 = &expression_parsers[token.type];
3680         source_position_t             source_position = token.source_position;
3681         expression_t                 *left;
3682
3683         if(parser->parser != NULL) {
3684                 left = parser->parser(parser->precedence);
3685         } else {
3686                 left = parse_primary_expression();
3687         }
3688         assert(left != NULL);
3689         left->source_position = source_position;
3690
3691         while(true) {
3692                 if(token.type < 0) {
3693                         return expected_expression_error();
3694                 }
3695
3696                 parser = &expression_parsers[token.type];
3697                 if(parser->infix_parser == NULL)
3698                         break;
3699                 if(parser->infix_precedence < precedence)
3700                         break;
3701
3702                 left = parser->infix_parser(parser->infix_precedence, left);
3703
3704                 assert(left != NULL);
3705                 assert(left->type != EXPR_UNKNOWN);
3706                 left->source_position = source_position;
3707         }
3708
3709         return left;
3710 }
3711
3712 static expression_t *parse_expression(void)
3713 {
3714         return parse_sub_expression(1);
3715 }
3716
3717
3718
3719 static void register_expression_parser(parse_expression_function parser,
3720                                        int token_type, unsigned precedence)
3721 {
3722         expression_parser_function_t *entry = &expression_parsers[token_type];
3723
3724         if(entry->parser != NULL) {
3725                 fprintf(stderr, "for token ");
3726                 print_token_type(stderr, token_type);
3727                 fprintf(stderr, "\n");
3728                 panic("trying to register multiple expression parsers for a token");
3729         }
3730         entry->parser     = parser;
3731         entry->precedence = precedence;
3732 }
3733
3734 static void register_expression_infix_parser(
3735                 parse_expression_infix_function parser, int token_type,
3736                 unsigned precedence)
3737 {
3738         expression_parser_function_t *entry = &expression_parsers[token_type];
3739
3740         if(entry->infix_parser != NULL) {
3741                 fprintf(stderr, "for token ");
3742                 print_token_type(stderr, token_type);
3743                 fprintf(stderr, "\n");
3744                 panic("trying to register multiple infix expression parsers for a "
3745                       "token");
3746         }
3747         entry->infix_parser     = parser;
3748         entry->infix_precedence = precedence;
3749 }
3750
3751 static void init_expression_parsers(void)
3752 {
3753         memset(&expression_parsers, 0, sizeof(expression_parsers));
3754
3755         register_expression_infix_parser(parse_BINEXPR_MUL,         '*',        16);
3756         register_expression_infix_parser(parse_BINEXPR_DIV,         '/',        16);
3757         register_expression_infix_parser(parse_BINEXPR_MOD,         '%',        16);
3758         register_expression_infix_parser(parse_BINEXPR_SHIFTLEFT,   T_LESSLESS, 16);
3759         register_expression_infix_parser(parse_BINEXPR_SHIFTRIGHT,
3760                                                               T_GREATERGREATER, 16);
3761         register_expression_infix_parser(parse_BINEXPR_ADD,         '+',        15);
3762         register_expression_infix_parser(parse_BINEXPR_SUB,         '-',        15);
3763         register_expression_infix_parser(parse_BINEXPR_LESS,        '<',        14);
3764         register_expression_infix_parser(parse_BINEXPR_GREATER,     '>',        14);
3765         register_expression_infix_parser(parse_BINEXPR_LESSEQUAL, T_LESSEQUAL,  14);
3766         register_expression_infix_parser(parse_BINEXPR_GREATEREQUAL,
3767                                                                 T_GREATEREQUAL, 14);
3768         register_expression_infix_parser(parse_BINEXPR_EQUAL,     T_EQUALEQUAL, 13);
3769         register_expression_infix_parser(parse_BINEXPR_NOTEQUAL,
3770                                                         T_EXCLAMATIONMARKEQUAL, 13);
3771         register_expression_infix_parser(parse_BINEXPR_BITWISE_AND, '&',        12);
3772         register_expression_infix_parser(parse_BINEXPR_BITWISE_XOR, '^',        11);
3773         register_expression_infix_parser(parse_BINEXPR_BITWISE_OR,  '|',        10);
3774         register_expression_infix_parser(parse_BINEXPR_LOGICAL_AND, T_ANDAND,    9);
3775         register_expression_infix_parser(parse_BINEXPR_LOGICAL_OR,  T_PIPEPIPE,  8);
3776         register_expression_infix_parser(parse_conditional_expression, '?',      7);
3777         register_expression_infix_parser(parse_BINEXPR_ASSIGN,      '=',         2);
3778         register_expression_infix_parser(parse_BINEXPR_ADD_ASSIGN, T_PLUSEQUAL,  2);
3779         register_expression_infix_parser(parse_BINEXPR_SUB_ASSIGN, T_MINUSEQUAL, 2);
3780         register_expression_infix_parser(parse_BINEXPR_MUL_ASSIGN,
3781                                                                 T_ASTERISKEQUAL, 2);
3782         register_expression_infix_parser(parse_BINEXPR_DIV_ASSIGN, T_SLASHEQUAL, 2);
3783         register_expression_infix_parser(parse_BINEXPR_MOD_ASSIGN,
3784                                                                  T_PERCENTEQUAL, 2);
3785         register_expression_infix_parser(parse_BINEXPR_SHIFTLEFT_ASSIGN,
3786                                                                 T_LESSLESSEQUAL, 2);
3787         register_expression_infix_parser(parse_BINEXPR_SHIFTRIGHT_ASSIGN,
3788                                                           T_GREATERGREATEREQUAL, 2);
3789         register_expression_infix_parser(parse_BINEXPR_BITWISE_AND_ASSIGN,
3790                                                                      T_ANDEQUAL, 2);
3791         register_expression_infix_parser(parse_BINEXPR_BITWISE_OR_ASSIGN,
3792                                                                     T_PIPEEQUAL, 2);
3793         register_expression_infix_parser(parse_BINEXPR_BITWISE_XOR_ASSIGN,
3794                                                                    T_CARETEQUAL, 2);
3795
3796         register_expression_infix_parser(parse_BINEXPR_COMMA,       ',',         1);
3797
3798         register_expression_infix_parser(parse_array_expression,        '[',    30);
3799         register_expression_infix_parser(parse_call_expression,         '(',    30);
3800         register_expression_infix_parser(parse_select_expression,       '.',    30);
3801         register_expression_infix_parser(parse_select_expression,
3802                                                                 T_MINUSGREATER, 30);
3803         register_expression_infix_parser(parse_UNEXPR_POSTFIX_INCREMENT,
3804                                          T_PLUSPLUS, 30);
3805         register_expression_infix_parser(parse_UNEXPR_POSTFIX_DECREMENT,
3806                                          T_MINUSMINUS, 30);
3807
3808         register_expression_parser(parse_UNEXPR_NEGATE,           '-',          25);
3809         register_expression_parser(parse_UNEXPR_PLUS,             '+',          25);
3810         register_expression_parser(parse_UNEXPR_NOT,              '!',          25);
3811         register_expression_parser(parse_UNEXPR_BITWISE_NEGATE,   '~',          25);
3812         register_expression_parser(parse_UNEXPR_DEREFERENCE,      '*',          25);
3813         register_expression_parser(parse_UNEXPR_TAKE_ADDRESS,     '&',          25);
3814         register_expression_parser(parse_UNEXPR_PREFIX_INCREMENT, T_PLUSPLUS,   25);
3815         register_expression_parser(parse_UNEXPR_PREFIX_DECREMENT, T_MINUSMINUS, 25);
3816         register_expression_parser(parse_sizeof,                  T_sizeof,     25);
3817         register_expression_parser(parse_extension,            T___extension__, 25);
3818         register_expression_parser(parse_builtin_classify_type,
3819                                                      T___builtin_classify_type, 25);
3820 }
3821
3822
3823 static statement_t *parse_case_statement(void)
3824 {
3825         eat(T_case);
3826         case_label_statement_t *label = allocate_ast_zero(sizeof(label[0]));
3827         label->statement.type            = STATEMENT_CASE_LABEL;
3828         label->statement.source_position = token.source_position;
3829
3830         label->expression = parse_expression();
3831
3832         expect(':');
3833         label->label_statement = parse_statement();
3834
3835         return (statement_t*) label;
3836 }
3837
3838 static statement_t *parse_default_statement(void)
3839 {
3840         eat(T_default);
3841
3842         case_label_statement_t *label = allocate_ast_zero(sizeof(label[0]));
3843         label->statement.type            = STATEMENT_CASE_LABEL;
3844         label->statement.source_position = token.source_position;
3845
3846         expect(':');
3847         label->label_statement = parse_statement();
3848
3849         return (statement_t*) label;
3850 }
3851
3852 static declaration_t *get_label(symbol_t *symbol)
3853 {
3854         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
3855         assert(current_function != NULL);
3856         /* if we found a label in the same function, then we already created the
3857          * declaration */
3858         if(candidate != NULL
3859                         && candidate->parent_context == &current_function->context) {
3860                 return candidate;
3861         }
3862
3863         /* otherwise we need to create a new one */
3864         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
3865         declaration->namespc     = NAMESPACE_LABEL;
3866         declaration->symbol        = symbol;
3867
3868         label_push(declaration);
3869
3870         return declaration;
3871 }
3872
3873 static statement_t *parse_label_statement(void)
3874 {
3875         assert(token.type == T_IDENTIFIER);
3876         symbol_t *symbol = token.v.symbol;
3877         next_token();
3878
3879         declaration_t *label = get_label(symbol);
3880
3881         /* if source position is already set then the label is defined twice,
3882          * otherwise it was just mentioned in a goto so far */
3883         if(label->source_position.input_name != NULL) {
3884                 parser_print_error_prefix();
3885                 fprintf(stderr, "duplicate label '%s'\n", symbol->string);
3886                 parser_print_error_prefix_pos(label->source_position);
3887                 fprintf(stderr, "previous definition of '%s' was here\n",
3888                         symbol->string);
3889         } else {
3890                 label->source_position = token.source_position;
3891         }
3892
3893         label_statement_t *label_statement = allocate_ast_zero(sizeof(label[0]));
3894
3895         label_statement->statement.type            = STATEMENT_LABEL;
3896         label_statement->statement.source_position = token.source_position;
3897         label_statement->label                     = label;
3898
3899         expect(':');
3900
3901         if(token.type == '}') {
3902                 parse_error("label at end of compound statement");
3903                 return (statement_t*) label_statement;
3904         } else {
3905                 label_statement->label_statement = parse_statement();
3906         }
3907
3908         return (statement_t*) label_statement;
3909 }
3910
3911 static statement_t *parse_if(void)
3912 {
3913         eat(T_if);
3914
3915         if_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
3916         statement->statement.type            = STATEMENT_IF;
3917         statement->statement.source_position = token.source_position;
3918
3919         expect('(');
3920         statement->condition = parse_expression();
3921         expect(')');
3922
3923         statement->true_statement = parse_statement();
3924         if(token.type == T_else) {
3925                 next_token();
3926                 statement->false_statement = parse_statement();
3927         }
3928
3929         return (statement_t*) statement;
3930 }
3931
3932 static statement_t *parse_switch(void)
3933 {
3934         eat(T_switch);
3935
3936         switch_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
3937         statement->statement.type            = STATEMENT_SWITCH;
3938         statement->statement.source_position = token.source_position;
3939
3940         expect('(');
3941         statement->expression = parse_expression();
3942         expect(')');
3943         statement->body = parse_statement();
3944
3945         return (statement_t*) statement;
3946 }
3947
3948 static statement_t *parse_while(void)
3949 {
3950         eat(T_while);
3951
3952         while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
3953         statement->statement.type            = STATEMENT_WHILE;
3954         statement->statement.source_position = token.source_position;
3955
3956         expect('(');
3957         statement->condition = parse_expression();
3958         expect(')');
3959         statement->body = parse_statement();
3960
3961         return (statement_t*) statement;
3962 }
3963
3964 static statement_t *parse_do(void)
3965 {
3966         eat(T_do);
3967
3968         do_while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
3969         statement->statement.type            = STATEMENT_DO_WHILE;
3970         statement->statement.source_position = token.source_position;
3971
3972         statement->body = parse_statement();
3973         expect(T_while);
3974         expect('(');
3975         statement->condition = parse_expression();
3976         expect(')');
3977         expect(';');
3978
3979         return (statement_t*) statement;
3980 }
3981
3982 static statement_t *parse_for(void)
3983 {
3984         eat(T_for);
3985
3986         for_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
3987         statement->statement.type            = STATEMENT_FOR;
3988         statement->statement.source_position = token.source_position;
3989
3990         expect('(');
3991
3992         int         top          = environment_top();
3993         context_t  *last_context = context;
3994         set_context(&statement->context);
3995
3996         if(token.type != ';') {
3997                 if(is_declaration_specifier(&token, false)) {
3998                         parse_declaration();
3999                 } else {
4000                         statement->initialisation = parse_expression();
4001                         expect(';');
4002                 }
4003         } else {
4004                 expect(';');
4005         }
4006
4007         if(token.type != ';') {
4008                 statement->condition = parse_expression();
4009         }
4010         expect(';');
4011         if(token.type != ')') {
4012                 statement->step = parse_expression();
4013         }
4014         expect(')');
4015         statement->body = parse_statement();
4016
4017         assert(context == &statement->context);
4018         set_context(last_context);
4019         environment_pop_to(top);
4020
4021         return (statement_t*) statement;
4022 }
4023
4024 static statement_t *parse_goto(void)
4025 {
4026         eat(T_goto);
4027
4028         if(token.type != T_IDENTIFIER) {
4029                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
4030                 eat_statement();
4031                 return NULL;
4032         }
4033         symbol_t *symbol = token.v.symbol;
4034         next_token();
4035
4036         declaration_t *label = get_label(symbol);
4037
4038         goto_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4039
4040         statement->statement.type            = STATEMENT_GOTO;
4041         statement->statement.source_position = token.source_position;
4042
4043         statement->label = label;
4044
4045         expect(';');
4046
4047         return (statement_t*) statement;
4048 }
4049
4050 static statement_t *parse_continue(void)
4051 {
4052         eat(T_continue);
4053         expect(';');
4054
4055         statement_t *statement     = allocate_ast_zero(sizeof(statement[0]));
4056         statement->type            = STATEMENT_CONTINUE;
4057         statement->source_position = token.source_position;
4058
4059         return statement;
4060 }
4061
4062 static statement_t *parse_break(void)
4063 {
4064         eat(T_break);
4065         expect(';');
4066
4067         statement_t *statement     = allocate_ast_zero(sizeof(statement[0]));
4068         statement->type            = STATEMENT_BREAK;
4069         statement->source_position = token.source_position;
4070
4071         return statement;
4072 }
4073
4074 static statement_t *parse_return(void)
4075 {
4076         eat(T_return);
4077
4078         return_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4079
4080         statement->statement.type            = STATEMENT_RETURN;
4081         statement->statement.source_position = token.source_position;
4082
4083         assert(current_function->type->type == TYPE_FUNCTION);
4084         function_type_t *function_type = (function_type_t*) current_function->type;
4085         type_t          *return_type   = function_type->result_type;
4086
4087         expression_t *return_value;
4088         if(token.type != ';') {
4089                 return_value = parse_expression();
4090
4091                 if(return_type == type_void && return_value->datatype != type_void) {
4092                         parse_warning("'return' with a value, in function returning void");
4093                         return_value = NULL;
4094                 } else {
4095                         if(return_type != NULL) {
4096                                 semantic_assign(return_type, &return_value, "'return'");
4097                         }
4098                 }
4099         } else {
4100                 return_value = NULL;
4101                 if(return_type != type_void) {
4102                         parse_warning("'return' without value, in function returning "
4103                                       "non-void");
4104                 }
4105         }
4106         statement->return_value = return_value;
4107
4108         expect(';');
4109
4110         return (statement_t*) statement;
4111 }
4112
4113 static statement_t *parse_declaration_statement(void)
4114 {
4115         declaration_t *before = last_declaration;
4116
4117         declaration_statement_t *statement
4118                 = allocate_ast_zero(sizeof(statement[0]));
4119         statement->statement.type            = STATEMENT_DECLARATION;
4120         statement->statement.source_position = token.source_position;
4121
4122         declaration_specifiers_t specifiers;
4123         memset(&specifiers, 0, sizeof(specifiers));
4124         parse_declaration_specifiers(&specifiers);
4125
4126         if(token.type == ';') {
4127                 eat(';');
4128         } else {
4129                 parse_init_declarators(&specifiers);
4130         }
4131
4132         if(before == NULL) {
4133                 statement->declarations_begin = context->declarations;
4134         } else {
4135                 statement->declarations_begin = before->next;
4136         }
4137         statement->declarations_end = last_declaration;
4138
4139         return (statement_t*) statement;
4140 }
4141
4142 static statement_t *parse_expression_statement(void)
4143 {
4144         expression_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4145         statement->statement.type            = STATEMENT_EXPRESSION;
4146         statement->statement.source_position = token.source_position;
4147
4148         statement->expression = parse_expression();
4149
4150         expect(';');
4151
4152         return (statement_t*) statement;
4153 }
4154
4155 static statement_t *parse_statement(void)
4156 {
4157         statement_t   *statement = NULL;
4158
4159         /* declaration or statement */
4160         switch(token.type) {
4161         case T_case:
4162                 statement = parse_case_statement();
4163                 break;
4164
4165         case T_default:
4166                 statement = parse_default_statement();
4167                 break;
4168
4169         case '{':
4170                 statement = parse_compound_statement();
4171                 break;
4172
4173         case T_if:
4174                 statement = parse_if();
4175                 break;
4176
4177         case T_switch:
4178                 statement = parse_switch();
4179                 break;
4180
4181         case T_while:
4182                 statement = parse_while();
4183                 break;
4184
4185         case T_do:
4186                 statement = parse_do();
4187                 break;
4188
4189         case T_for:
4190                 statement = parse_for();
4191                 break;
4192
4193         case T_goto:
4194                 statement = parse_goto();
4195                 break;
4196
4197         case T_continue:
4198                 statement = parse_continue();
4199                 break;
4200
4201         case T_break:
4202                 statement = parse_break();
4203                 break;
4204
4205         case T_return:
4206                 statement = parse_return();
4207                 break;
4208
4209         case ';':
4210                 next_token();
4211                 statement = NULL;
4212                 break;
4213
4214         case T_IDENTIFIER:
4215                 if(look_ahead(1)->type == ':') {
4216                         statement = parse_label_statement();
4217                         break;
4218                 }
4219
4220                 if(is_typedef_symbol(token.v.symbol)) {
4221                         statement = parse_declaration_statement();
4222                         break;
4223                 }
4224
4225                 statement = parse_expression_statement();
4226                 break;
4227
4228         case T___extension__:
4229                 /* this can be a prefix to a declaration or an expression statement */
4230                 /* we simply eat it now and parse the rest with tail recursion */
4231                 do {
4232                         next_token();
4233                 } while(token.type == T___extension__);
4234                 statement = parse_statement();
4235                 break;
4236
4237         DECLARATION_START
4238                 statement = parse_declaration_statement();
4239                 break;
4240
4241         default:
4242                 statement = parse_expression_statement();
4243                 break;
4244         }
4245
4246         assert(statement == NULL || statement->source_position.input_name != NULL);
4247
4248         return statement;
4249 }
4250
4251 static statement_t *parse_compound_statement(void)
4252 {
4253         compound_statement_t *compound_statement
4254                 = allocate_ast_zero(sizeof(compound_statement[0]));
4255         compound_statement->statement.type            = STATEMENT_COMPOUND;
4256         compound_statement->statement.source_position = token.source_position;
4257
4258         eat('{');
4259
4260         int        top          = environment_top();
4261         context_t *last_context = context;
4262         set_context(&compound_statement->context);
4263
4264         statement_t *last_statement = NULL;
4265
4266         while(token.type != '}' && token.type != T_EOF) {
4267                 statement_t *statement = parse_statement();
4268                 if(statement == NULL)
4269                         continue;
4270
4271                 if(last_statement != NULL) {
4272                         last_statement->next = statement;
4273                 } else {
4274                         compound_statement->statements = statement;
4275                 }
4276
4277                 while(statement->next != NULL)
4278                         statement = statement->next;
4279
4280                 last_statement = statement;
4281         }
4282
4283         if(token.type != '}') {
4284                 parser_print_error_prefix_pos(
4285                                 compound_statement->statement.source_position);
4286                 fprintf(stderr, "end of file while looking for closing '}'\n");
4287         }
4288         next_token();
4289
4290         assert(context == &compound_statement->context);
4291         set_context(last_context);
4292         environment_pop_to(top);
4293
4294         return (statement_t*) compound_statement;
4295 }
4296
4297 static translation_unit_t *parse_translation_unit(void)
4298 {
4299         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
4300
4301         assert(global_context == NULL);
4302         global_context = &unit->context;
4303
4304         assert(context == NULL);
4305         set_context(&unit->context);
4306
4307         while(token.type != T_EOF) {
4308                 parse_declaration();
4309         }
4310
4311         assert(context == &unit->context);
4312         context          = NULL;
4313         last_declaration = NULL;
4314
4315         assert(global_context == &unit->context);
4316         global_context = NULL;
4317
4318         return unit;
4319 }
4320
4321 translation_unit_t *parse(void)
4322 {
4323         environment_stack = NEW_ARR_F(stack_entry_t, 0);
4324         label_stack       = NEW_ARR_F(stack_entry_t, 0);
4325         found_error       = false;
4326
4327         type_set_output(stderr);
4328         ast_set_output(stderr);
4329
4330         lookahead_bufpos = 0;
4331         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
4332                 next_token();
4333         }
4334         translation_unit_t *unit = parse_translation_unit();
4335
4336         DEL_ARR_F(environment_stack);
4337         DEL_ARR_F(label_stack);
4338
4339         if(found_error)
4340                 return NULL;
4341
4342         return unit;
4343 }
4344
4345 void init_parser(void)
4346 {
4347         init_expression_parsers();
4348         obstack_init(&temp_obst);
4349
4350         type_int         = make_atomic_type(ATOMIC_TYPE_INT, 0);
4351         type_uint        = make_atomic_type(ATOMIC_TYPE_UINT, 0);
4352         type_long_double = make_atomic_type(ATOMIC_TYPE_LONG_DOUBLE, 0);
4353         type_double      = make_atomic_type(ATOMIC_TYPE_DOUBLE, 0);
4354         type_float       = make_atomic_type(ATOMIC_TYPE_FLOAT, 0);
4355         type_size_t      = make_atomic_type(ATOMIC_TYPE_ULONG, 0);
4356         type_ptrdiff_t   = make_atomic_type(ATOMIC_TYPE_LONG, 0);
4357         type_const_char  = make_atomic_type(ATOMIC_TYPE_CHAR, TYPE_QUALIFIER_CONST);
4358         type_void        = make_atomic_type(ATOMIC_TYPE_VOID, 0);
4359         type_void_ptr    = make_pointer_type(type_void, 0);
4360         type_string      = make_pointer_type(type_const_char, 0);
4361 }
4362
4363 void exit_parser(void)
4364 {
4365         obstack_free(&temp_obst, NULL);
4366 }