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