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 "diagnostic.h"
   8 #include "format_check.h"
   9 #include "parser.h"
  10 #include "lexer.h"
  11 #include "token_t.h"
  12 #include "types.h"
  13 #include "type_t.h"
  14 #include "type_hash.h"
  15 #include "ast_t.h"
  16 #include "adt/bitfiddle.h"
  17 #include "adt/error.h"
  18 #include "adt/array.h"
  19
  20 //#define PRINT_TOKENS
  21 //#define ABORT_ON_ERROR
  22 #define MAX_LOOKAHEAD 2
  23 //#define STRICT_C99
  24
  25 typedef struct {
  26         declaration_t *old_declaration;
  27         symbol_t      *symbol;
  28         unsigned short namespc;
  29 } stack_entry_t;
  30
  31 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  32 struct declaration_specifiers_t {
  33         source_position_t  source_position;
  34         unsigned char      storage_class;
  35         bool               is_inline;
  36         decl_modifiers_t   decl_modifiers;
  37         type_t            *type;
  38 };
  39
  40 typedef declaration_t* (*parsed_declaration_func) (declaration_t *declaration);
  41
  42 static token_t         token;
  43 static token_t         lookahead_buffer[MAX_LOOKAHEAD];
  44 static int             lookahead_bufpos;
  45 static stack_entry_t  *environment_stack = NULL;
  46 static stack_entry_t  *label_stack       = NULL;
  47 static context_t      *global_context    = NULL;
  48 static context_t      *context           = NULL;
  49 static declaration_t  *last_declaration  = NULL;
  50 static declaration_t  *current_function  = NULL;
  51 static struct obstack  temp_obst;
  52 static bool            found_error;
  53
  54 static type_t *type_valist;
  55
  56 static statement_t *parse_compound_statement(void);
  57 static statement_t *parse_statement(void);
  58
  59 static expression_t *parse_sub_expression(unsigned precedence);
  60 static expression_t *parse_expression(void);
  61 static type_t       *parse_typename(void);
  62
  63 static void parse_compound_type_entries(void);
  64 static declaration_t *parse_declarator(
  65                 const declaration_specifiers_t *specifiers, bool may_be_abstract);
  66 static declaration_t *record_declaration(declaration_t *declaration);
  67
  68 static void semantic_comparison(binary_expression_t *expression);
  69
  70 #define STORAGE_CLASSES     \
  71         case T_typedef:         \
  72         case T_extern:          \
  73         case T_static:          \
  74         case T_auto:            \
  75         case T_register:
  76
  77 #define TYPE_QUALIFIERS     \
  78         case T_const:           \
  79         case T_restrict:        \
  80         case T_volatile:        \
  81         case T_inline:          \
  82         case T_forceinline:
  83
  84 #ifdef PROVIDE_COMPLEX
  85 #define COMPLEX_SPECIFIERS  \
  86         case T__Complex:
  87 #define IMAGINARY_SPECIFIERS \
  88         case T__Imaginary:
  89 #else
  90 #define COMPLEX_SPECIFIERS
  91 #define IMAGINARY_SPECIFIERS
  92 #endif
  93
  94 #define TYPE_SPECIFIERS       \
  95         case T_void:              \
  96         case T_char:              \
  97         case T_short:             \
  98         case T_int:               \
  99         case T_long:              \
 100         case T_float:             \
 101         case T_double:            \
 102         case T_signed:            \
 103         case T_unsigned:          \
 104         case T__Bool:             \
 105         case T_struct:            \
 106         case T_union:             \
 107         case T_enum:              \
 108         case T___typeof__:        \
 109         case T___builtin_va_list: \
 110         COMPLEX_SPECIFIERS        \
 111         IMAGINARY_SPECIFIERS
 112
 113 #define DECLARATION_START   \
 114         STORAGE_CLASSES         \
 115         TYPE_QUALIFIERS         \
 116         TYPE_SPECIFIERS
 117
 118 #define TYPENAME_START      \
 119         TYPE_QUALIFIERS         \
 120         TYPE_SPECIFIERS
 121
 122 static void *allocate_ast_zero(size_t size)
 123 {
 124         void *res = allocate_ast(size);
 125         memset(res, 0, size);
 126         return res;
 127 }
 128
 129 static size_t get_statement_struct_size(statement_kind_t kind)
 130 {
 131         static const size_t sizes[] = {
 132                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 133                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 134                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 135                 [STATEMENT_IF]          = sizeof(if_statement_t),
 136                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 137                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 138                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 139                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 140                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 141                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 142                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 143                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 144                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 145                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 146                 [STATEMENT_ASM]         = sizeof(asm_statement_t)
 147         };
 148         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 149         assert(sizes[kind] != 0);
 150         return sizes[kind];
 151 }
 152
 153 static statement_t *allocate_statement_zero(statement_kind_t kind)
 154 {
 155         size_t       size = get_statement_struct_size(kind);
 156         statement_t *res  = allocate_ast_zero(size);
 157
 158         res->base.kind = kind;
 159         return res;
 160 }
 161
 162
 163 static size_t get_expression_struct_size(expression_kind_t type)
 164 {
 165         static const size_t sizes[] = {
 166                 [EXPR_INVALID]             = sizeof(expression_base_t),
 167                 [EXPR_REFERENCE]           = sizeof(reference_expression_t),
 168                 [EXPR_CONST]               = sizeof(const_expression_t),
 169                 [EXPR_STRING_LITERAL]      = sizeof(string_literal_expression_t),
 170                 [EXPR_WIDE_STRING_LITERAL] = sizeof(wide_string_literal_expression_t),
 171                 [EXPR_CALL]                = sizeof(call_expression_t),
 172                 [EXPR_UNARY_FIRST]         = sizeof(unary_expression_t),
 173                 [EXPR_BINARY_FIRST]        = sizeof(binary_expression_t),
 174                 [EXPR_CONDITIONAL]         = sizeof(conditional_expression_t),
 175                 [EXPR_SELECT]              = sizeof(select_expression_t),
 176                 [EXPR_ARRAY_ACCESS]        = sizeof(array_access_expression_t),
 177                 [EXPR_SIZEOF]              = sizeof(sizeof_expression_t),
 178                 [EXPR_CLASSIFY_TYPE]       = sizeof(classify_type_expression_t),
 179                 [EXPR_FUNCTION]            = sizeof(string_literal_expression_t),
 180                 [EXPR_PRETTY_FUNCTION]     = sizeof(string_literal_expression_t),
 181                 [EXPR_BUILTIN_SYMBOL]      = sizeof(builtin_symbol_expression_t),
 182                 [EXPR_OFFSETOF]            = sizeof(offsetof_expression_t),
 183                 [EXPR_VA_START]            = sizeof(va_start_expression_t),
 184                 [EXPR_VA_ARG]              = sizeof(va_arg_expression_t),
 185                 [EXPR_STATEMENT]           = sizeof(statement_expression_t),
 186         };
 187         if(type >= EXPR_UNARY_FIRST && type <= EXPR_UNARY_LAST) {
 188                 return sizes[EXPR_UNARY_FIRST];
 189         }
 190         if(type >= EXPR_BINARY_FIRST && type <= EXPR_BINARY_LAST) {
 191                 return sizes[EXPR_BINARY_FIRST];
 192         }
 193         assert(type <= sizeof(sizes) / sizeof(sizes[0]));
 194         assert(sizes[type] != 0);
 195         return sizes[type];
 196 }
 197
 198 static expression_t *allocate_expression_zero(expression_kind_t kind)
 199 {
 200         size_t        size = get_expression_struct_size(kind);
 201         expression_t *res  = allocate_ast_zero(size);
 202
 203         res->base.kind = kind;
 204         return res;
 205 }
 206
 207 static size_t get_type_struct_size(type_kind_t kind)
 208 {
 209         static const size_t sizes[] = {
 210                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 211                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 212                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 213                 [TYPE_ENUM]            = sizeof(enum_type_t),
 214                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 215                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 216                 [TYPE_ARRAY]           = sizeof(array_type_t),
 217                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 218                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 219                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 220         };
 221         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 222         assert(kind <= TYPE_TYPEOF);
 223         assert(sizes[kind] != 0);
 224         return sizes[kind];
 225 }
 226
 227 static type_t *allocate_type_zero(type_kind_t kind)
 228 {
 229         size_t  size = get_type_struct_size(kind);
 230         type_t *res  = obstack_alloc(type_obst, size);
 231         memset(res, 0, size);
 232
 233         res->base.kind = kind;
 234         return res;
 235 }
 236
 237 static size_t get_initializer_size(initializer_kind_t kind)
 238 {
 239         static const size_t sizes[] = {
 240                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 241                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 242                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 243                 [INITIALIZER_LIST]        = sizeof(initializer_list_t)
 244         };
 245         assert(kind < sizeof(sizes) / sizeof(*sizes));
 246         assert(sizes[kind] != 0);
 247         return sizes[kind];
 248 }
 249
 250 static initializer_t *allocate_initializer(initializer_kind_t kind)
 251 {
 252         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 253         result->kind          = kind;
 254
 255         return result;
 256 }
 257
 258 static void free_type(void *type)
 259 {
 260         obstack_free(type_obst, type);
 261 }
 262
 263 /**
 264  * returns the top element of the environment stack
 265  */
 266 static size_t environment_top(void)
 267 {
 268         return ARR_LEN(environment_stack);
 269 }
 270
 271 static size_t label_top(void)
 272 {
 273         return ARR_LEN(label_stack);
 274 }
 275
 276
 277
 278 static inline void next_token(void)
 279 {
 280         token                              = lookahead_buffer[lookahead_bufpos];
 281         lookahead_buffer[lookahead_bufpos] = lexer_token;
 282         lexer_next_token();
 283
 284         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 285
 286 #ifdef PRINT_TOKENS
 287         print_token(stderr, &token);
 288         fprintf(stderr, "\n");
 289 #endif
 290 }
 291
 292 static inline const token_t *look_ahead(int num)
 293 {
 294         assert(num > 0 && num <= MAX_LOOKAHEAD);
 295         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 296         return &lookahead_buffer[pos];
 297 }
 298
 299 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
 300
 301 static void error(void)
 302 {
 303         found_error = true;
 304 #ifdef ABORT_ON_ERROR
 305         abort();
 306 #endif
 307 }
 308
 309 static void parser_print_error_prefix_pos(
 310                 const source_position_t source_position)
 311 {
 312         parser_print_prefix_pos(source_position);
 313         fputs("error: ", stderr);
 314         error();
 315 }
 316
 317 static void parser_print_error_prefix(void)
 318 {
 319         parser_print_error_prefix_pos(token.source_position);
 320 }
 321
 322 static void parse_error(const char *message)
 323 {
 324         parser_print_error_prefix();
 325         fprintf(stderr, "parse error: %s\n", message);
 326 }
 327
 328 static void parser_print_warning_prefix(void)
 329 {
 330         parser_print_warning_prefix_pos(token.source_position);
 331 }
 332
 333 static void parse_warning(const char *message)
 334 {
 335         parse_warning_pos(token.source_position, message);
 336 }
 337
 338 static void parse_error_expected(const char *message, ...)
 339 {
 340         va_list args;
 341         int first = 1;
 342
 343         if(message != NULL) {
 344                 parser_print_error_prefix();
 345                 fprintf(stderr, "%s\n", message);
 346         }
 347         parser_print_error_prefix();
 348         fputs("Parse error: got ", stderr);
 349         print_token(stderr, &token);
 350         fputs(", expected ", stderr);
 351
 352         va_start(args, message);
 353         token_type_t token_type = va_arg(args, token_type_t);
 354         while(token_type != 0) {
 355                 if(first == 1) {
 356                         first = 0;
 357                 } else {
 358                         fprintf(stderr, ", ");
 359                 }
 360                 print_token_type(stderr, token_type);
 361                 token_type = va_arg(args, token_type_t);
 362         }
 363         va_end(args);
 364         fprintf(stderr, "\n");
 365 }
 366
 367 static void print_type_quoted(type_t *type)
 368 {
 369         fputc('\'', stderr);
 370         print_type(type);
 371         fputc('\'', stderr);
 372 }
 373
 374 static void type_error(const char *msg, const source_position_t source_position,
 375                        type_t *type)
 376 {
 377         parser_print_error_prefix_pos(source_position);
 378         fprintf(stderr, "%s, but found type ", msg);
 379         print_type_quoted(type);
 380         fputc('\n', stderr);
 381 }
 382
 383 static void type_error_incompatible(const char *msg,
 384                 const source_position_t source_position, type_t *type1, type_t *type2)
 385 {
 386         parser_print_error_prefix_pos(source_position);
 387         fprintf(stderr, "%s, incompatible types: ", msg);
 388         print_type_quoted(type1);
 389         fprintf(stderr, " - ");
 390         print_type_quoted(type2);
 391         fprintf(stderr, ")\n");
 392 }
 393
 394 static void eat_block(void)
 395 {
 396         if(token.type == '{')
 397                 next_token();
 398
 399         while(token.type != '}') {
 400                 if(token.type == T_EOF)
 401                         return;
 402                 if(token.type == '{') {
 403                         eat_block();
 404                         continue;
 405                 }
 406                 next_token();
 407         }
 408         eat('}');
 409 }
 410
 411 static void eat_statement(void)
 412 {
 413         while(token.type != ';') {
 414                 if(token.type == T_EOF)
 415                         return;
 416                 if(token.type == '}')
 417                         return;
 418                 if(token.type == '{') {
 419                         eat_block();
 420                         continue;
 421                 }
 422                 next_token();
 423         }
 424         eat(';');
 425 }
 426
 427 static void eat_paren(void)
 428 {
 429         if(token.type == '(')
 430                 next_token();
 431
 432         while(token.type != ')') {
 433                 if(token.type == T_EOF)
 434                         return;
 435                 if(token.type == ')' || token.type == ';' || token.type == '}') {
 436                         return;
 437                 }
 438                 if(token.type == '(') {
 439                         eat_paren();
 440                         continue;
 441                 }
 442                 if(token.type == '{') {
 443                         eat_block();
 444                         continue;
 445                 }
 446                 next_token();
 447         }
 448         eat(')');
 449 }
 450
 451 #define expect(expected)                           \
 452     if(UNLIKELY(token.type != (expected))) {       \
 453         parse_error_expected(NULL, (expected), 0); \
 454         eat_statement();                           \
 455         return NULL;                               \
 456     }                                              \
 457     next_token();
 458
 459 #define expect_block(expected)                     \
 460     if(UNLIKELY(token.type != (expected))) {       \
 461         parse_error_expected(NULL, (expected), 0); \
 462         eat_block();                               \
 463         return NULL;                               \
 464     }                                              \
 465     next_token();
 466
 467 #define expect_void(expected)                      \
 468     if(UNLIKELY(token.type != (expected))) {       \
 469         parse_error_expected(NULL, (expected), 0); \
 470         eat_statement();                           \
 471         return;                                    \
 472     }                                              \
 473     next_token();
 474
 475 static void set_context(context_t *new_context)
 476 {
 477         context = new_context;
 478
 479         last_declaration = new_context->declarations;
 480         if(last_declaration != NULL) {
 481                 while(last_declaration->next != NULL) {
 482                         last_declaration = last_declaration->next;
 483                 }
 484         }
 485 }
 486
 487 /**
 488  * called when we find a 2nd declarator for an identifier we already have a
 489  * declarator for
 490  */
 491 static bool is_compatible_declaration(declaration_t *declaration,
 492                                       declaration_t *previous)
 493 {
 494         /* happens for K&R style function parameters */
 495         if(previous->type == NULL) {
 496                 previous->type = declaration->type;
 497                 return true;
 498         }
 499
 500         type_t *type1 = skip_typeref(declaration->type);
 501         type_t *type2 = skip_typeref(previous->type);
 502
 503         return types_compatible(type1, type2);
 504 }
 505
 506 static declaration_t *get_declaration(symbol_t *symbol, namespace_t namespc)
 507 {
 508         declaration_t *declaration = symbol->declaration;
 509         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 510                 if(declaration->namespc == namespc)
 511                         return declaration;
 512         }
 513
 514         return NULL;
 515 }
 516
 517 static const char *get_namespace_prefix(namespace_t namespc)
 518 {
 519         switch(namespc) {
 520         case NAMESPACE_NORMAL:
 521                 return "";
 522         case NAMESPACE_UNION:
 523                 return "union ";
 524         case NAMESPACE_STRUCT:
 525                 return "struct ";
 526         case NAMESPACE_ENUM:
 527                 return "enum ";
 528         case NAMESPACE_LABEL:
 529                 return "label ";
 530         }
 531         panic("invalid namespace found");
 532 }
 533
 534 /**
 535  * pushs an environment_entry on the environment stack and links the
 536  * corresponding symbol to the new entry
 537  */
 538 static declaration_t *stack_push(stack_entry_t **stack_ptr,
 539                                  declaration_t *declaration,
 540                                  context_t *parent_context)
 541 {
 542         symbol_t    *symbol    = declaration->symbol;
 543         namespace_t  namespc = (namespace_t)declaration->namespc;
 544
 545         /* a declaration should be only pushed once */
 546         declaration->parent_context = parent_context;
 547
 548         declaration_t *previous_declaration = get_declaration(symbol, namespc);
 549         assert(declaration != previous_declaration);
 550         if(previous_declaration != NULL
 551                         && previous_declaration->parent_context == context) {
 552                 if(!is_compatible_declaration(declaration, previous_declaration)) {
 553                         parser_print_error_prefix_pos(declaration->source_position);
 554                         fprintf(stderr, "definition of symbol '%s%s' with type ",
 555                                         get_namespace_prefix(namespc), symbol->string);
 556                         print_type_quoted(declaration->type);
 557                         fputc('\n', stderr);
 558                         parser_print_error_prefix_pos(
 559                                         previous_declaration->source_position);
 560                         fprintf(stderr, "is incompatible with previous declaration "
 561                                         "of type ");
 562                         print_type_quoted(previous_declaration->type);
 563                         fputc('\n', stderr);
 564                 } else {
 565                         unsigned  old_storage_class = previous_declaration->storage_class;
 566                         unsigned  new_storage_class = declaration->storage_class;
 567                         type_t   *type              = previous_declaration->type;
 568                         type = skip_typeref(type);
 569
 570                         if (current_function == NULL) {
 571                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
 572                                     new_storage_class == STORAGE_CLASS_STATIC) {
 573                                         parser_print_error_prefix_pos(declaration->source_position);
 574                                         fprintf(stderr,
 575                                                 "static declaration of '%s' follows non-static declaration\n",
 576                                                 symbol->string);
 577                                         parser_print_error_prefix_pos(previous_declaration->source_position);
 578                                         fprintf(stderr, "previous declaration of '%s' was here\n",
 579                                                 symbol->string);
 580                                 } else {
 581                                         if (old_storage_class == STORAGE_CLASS_EXTERN) {
 582                                                 if (new_storage_class == STORAGE_CLASS_NONE) {
 583                                                         previous_declaration->storage_class = STORAGE_CLASS_NONE;
 584                                                 }
 585                                         } else if(!is_type_function(type)) {
 586                                                 parser_print_warning_prefix_pos(declaration->source_position);
 587                                                 fprintf(stderr, "redundant declaration for '%s'\n",
 588                                                                                 symbol->string);
 589                                                 parser_print_warning_prefix_pos(previous_declaration->source_position);
 590                                                 fprintf(stderr, "previous declaration of '%s' was here\n",
 591                                                                                 symbol->string);
 592                                         }
 593                                 }
 594                         } else {
 595                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
 596                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
 597                                         parser_print_warning_prefix_pos(declaration->source_position);
 598                                         fprintf(stderr, "redundant extern declaration for '%s'\n",
 599                                                 symbol->string);
 600                                         parser_print_warning_prefix_pos(previous_declaration->source_position);
 601                                         fprintf(stderr, "previous declaration of '%s' was here\n",
 602                                                 symbol->string);
 603                                 } else {
 604                                         parser_print_error_prefix_pos(declaration->source_position);
 605                                         if (old_storage_class == new_storage_class) {
 606                                                 fprintf(stderr, "redeclaration of '%s'\n", symbol->string);
 607                                         } else {
 608                                                 fprintf(stderr, "redeclaration of '%s' with different linkage\n", symbol->string);
 609                                         }
 610                                         parser_print_error_prefix_pos(previous_declaration->source_position);
 611                                         fprintf(stderr, "previous declaration of '%s' was here\n",
 612                                                 symbol->string);
 613                                 }
 614                         }
 615                 }
 616                 return previous_declaration;
 617         }
 618
 619         /* remember old declaration */
 620         stack_entry_t entry;
 621         entry.symbol          = symbol;
 622         entry.old_declaration = symbol->declaration;
 623         entry.namespc         = (unsigned short) namespc;
 624         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 625
 626         /* replace/add declaration into declaration list of the symbol */
 627         if(symbol->declaration == NULL) {
 628                 symbol->declaration = declaration;
 629         } else {
 630                 declaration_t *iter_last = NULL;
 631                 declaration_t *iter      = symbol->declaration;
 632                 for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 633                         /* replace an entry? */
 634                         if(iter->namespc == namespc) {
 635                                 if(iter_last == NULL) {
 636                                         symbol->declaration = declaration;
 637                                 } else {
 638                                         iter_last->symbol_next = declaration;
 639                                 }
 640                                 declaration->symbol_next = iter->symbol_next;
 641                                 break;
 642                         }
 643                 }
 644                 if(iter == NULL) {
 645                         assert(iter_last->symbol_next == NULL);
 646                         iter_last->symbol_next = declaration;
 647                 }
 648         }
 649
 650         return declaration;
 651 }
 652
 653 static declaration_t *environment_push(declaration_t *declaration)
 654 {
 655         assert(declaration->source_position.input_name != NULL);
 656         return stack_push(&environment_stack, declaration, context);
 657 }
 658
 659 static declaration_t *label_push(declaration_t *declaration)
 660 {
 661         return stack_push(&label_stack, declaration, &current_function->context);
 662 }
 663
 664 /**
 665  * pops symbols from the environment stack until @p new_top is the top element
 666  */
 667 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 668 {
 669         stack_entry_t *stack = *stack_ptr;
 670         size_t         top   = ARR_LEN(stack);
 671         size_t         i;
 672
 673         assert(new_top <= top);
 674         if(new_top == top)
 675                 return;
 676
 677         for(i = top; i > new_top; --i) {
 678                 stack_entry_t *entry = &stack[i - 1];
 679
 680                 declaration_t *old_declaration = entry->old_declaration;
 681                 symbol_t      *symbol          = entry->symbol;
 682                 namespace_t    namespc         = (namespace_t)entry->namespc;
 683
 684                 /* replace/remove declaration */
 685                 declaration_t *declaration = symbol->declaration;
 686                 assert(declaration != NULL);
 687                 if(declaration->namespc == namespc) {
 688                         if(old_declaration == NULL) {
 689                                 symbol->declaration = declaration->symbol_next;
 690                         } else {
 691                                 symbol->declaration = old_declaration;
 692                         }
 693                 } else {
 694                         declaration_t *iter_last = declaration;
 695                         declaration_t *iter      = declaration->symbol_next;
 696                         for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 697                                 /* replace an entry? */
 698                                 if(iter->namespc == namespc) {
 699                                         assert(iter_last != NULL);
 700                                         iter_last->symbol_next = old_declaration;
 701                                         old_declaration->symbol_next = iter->symbol_next;
 702                                         break;
 703                                 }
 704                         }
 705                         assert(iter != NULL);
 706                 }
 707         }
 708
 709         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 710 }
 711
 712 static void environment_pop_to(size_t new_top)
 713 {
 714         stack_pop_to(&environment_stack, new_top);
 715 }
 716
 717 static void label_pop_to(size_t new_top)
 718 {
 719         stack_pop_to(&label_stack, new_top);
 720 }
 721
 722
 723 static int get_rank(const type_t *type)
 724 {
 725         assert(!is_typeref(type));
 726         /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
 727          * and esp. footnote 108). However we can't fold constants (yet), so we
 728          * can't decide whether unsigned int is possible, while int always works.
 729          * (unsigned int would be preferable when possible... for stuff like
 730          *  struct { enum { ... } bla : 4; } ) */
 731         if(type->kind == TYPE_ENUM)
 732                 return ATOMIC_TYPE_INT;
 733
 734         assert(type->kind == TYPE_ATOMIC);
 735         const atomic_type_t *atomic_type = &type->atomic;
 736         atomic_type_type_t   atype       = atomic_type->atype;
 737         return atype;
 738 }
 739
 740 static type_t *promote_integer(type_t *type)
 741 {
 742         if(get_rank(type) < ATOMIC_TYPE_INT)
 743                 type = type_int;
 744
 745         return type;
 746 }
 747
 748 static expression_t *create_cast_expression(expression_t *expression,
 749                                             type_t *dest_type)
 750 {
 751         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 752
 753         cast->unary.value   = expression;
 754         cast->base.datatype = dest_type;
 755
 756         return cast;
 757 }
 758
 759 static bool is_null_pointer_constant(const expression_t *expression)
 760 {
 761         /* skip void* cast */
 762         if(expression->kind == EXPR_UNARY_CAST
 763                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 764                 expression = expression->unary.value;
 765         }
 766
 767         /* TODO: not correct yet, should be any constant integer expression
 768          * which evaluates to 0 */
 769         if (expression->kind != EXPR_CONST)
 770                 return false;
 771
 772         type_t *const type = skip_typeref(expression->base.datatype);
 773         if (!is_type_integer(type))
 774                 return false;
 775
 776         return expression->conste.v.int_value == 0;
 777 }
 778
 779 static expression_t *create_implicit_cast(expression_t *expression,
 780                                           type_t *dest_type)
 781 {
 782         type_t *source_type = expression->base.datatype;
 783
 784         if(source_type == NULL)
 785                 return expression;
 786
 787         source_type = skip_typeref(source_type);
 788         dest_type   = skip_typeref(dest_type);
 789
 790         if(source_type == dest_type)
 791                 return expression;
 792
 793         switch (dest_type->kind) {
 794                 case TYPE_ENUM:
 795                         /* TODO warning for implicitly converting to enum */
 796                 case TYPE_ATOMIC:
 797                         if (source_type->kind != TYPE_ATOMIC &&
 798                                         source_type->kind != TYPE_ENUM) {
 799                                 panic("casting of non-atomic types not implemented yet");
 800                         }
 801
 802                         if(is_type_floating(dest_type) && !is_type_scalar(source_type)) {
 803                                 type_error_incompatible("can't cast types",
 804                                                 expression->base.source_position, source_type,
 805                                                 dest_type);
 806                                 return expression;
 807                         }
 808
 809                         return create_cast_expression(expression, dest_type);
 810
 811                 case TYPE_POINTER:
 812                         switch (source_type->kind) {
 813                                 case TYPE_ATOMIC:
 814                                         if (is_null_pointer_constant(expression)) {
 815                                                 return create_cast_expression(expression, dest_type);
 816                                         }
 817                                         break;
 818
 819                                 case TYPE_POINTER:
 820                                         if (pointers_compatible(source_type, dest_type)) {
 821                                                 return create_cast_expression(expression, dest_type);
 822                                         }
 823                                         break;
 824
 825                                 case TYPE_ARRAY: {
 826                                         array_type_t   *array_type   = &source_type->array;
 827                                         pointer_type_t *pointer_type = &dest_type->pointer;
 828                                         if (types_compatible(array_type->element_type,
 829                                                                                  pointer_type->points_to)) {
 830                                                 return create_cast_expression(expression, dest_type);
 831                                         }
 832                                         break;
 833                                 }
 834
 835                                 default:
 836                                         panic("casting of non-atomic types not implemented yet");
 837                         }
 838
 839                         type_error_incompatible("can't implicitly cast types",
 840                                         expression->base.source_position, source_type, dest_type);
 841                         return expression;
 842
 843                 default:
 844                         panic("casting of non-atomic types not implemented yet");
 845         }
 846 }
 847
 848 /** Implements the rules from § 6.5.16.1 */
 849 static void semantic_assign(type_t *orig_type_left, expression_t **right,
 850                             const char *context)
 851 {
 852         type_t *orig_type_right = (*right)->base.datatype;
 853
 854         if(orig_type_right == NULL)
 855                 return;
 856
 857         type_t *const type_left  = skip_typeref(orig_type_left);
 858         type_t *const type_right = skip_typeref(orig_type_right);
 859
 860         if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 861             (is_type_pointer(type_left) && is_null_pointer_constant(*right)) ||
 862             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 863                 && is_type_pointer(type_right))) {
 864                 *right = create_implicit_cast(*right, type_left);
 865                 return;
 866         }
 867
 868         if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
 869                 pointer_type_t *pointer_type_left  = &type_left->pointer;
 870                 pointer_type_t *pointer_type_right = &type_right->pointer;
 871                 type_t         *points_to_left     = pointer_type_left->points_to;
 872                 type_t         *points_to_right    = pointer_type_right->points_to;
 873
 874                 points_to_left  = skip_typeref(points_to_left);
 875                 points_to_right = skip_typeref(points_to_right);
 876
 877                 /* the left type has all qualifiers from the right type */
 878                 unsigned missing_qualifiers
 879                         = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 880                 if(missing_qualifiers != 0) {
 881                         parser_print_error_prefix();
 882                         fprintf(stderr, "destination type ");
 883                         print_type_quoted(type_left);
 884                         fprintf(stderr, " in %s from type ", context);
 885                         print_type_quoted(type_right);
 886                         fprintf(stderr, " lacks qualifiers '");
 887                         print_type_qualifiers(missing_qualifiers);
 888                         fprintf(stderr, "' in pointed-to type\n");
 889                         return;
 890                 }
 891
 892                 points_to_left  = get_unqualified_type(points_to_left);
 893                 points_to_right = get_unqualified_type(points_to_right);
 894
 895                 if(!is_type_atomic(points_to_left, ATOMIC_TYPE_VOID)
 896                                 && !is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)
 897                                 && !types_compatible(points_to_left, points_to_right)) {
 898                         goto incompatible_assign_types;
 899                 }
 900
 901                 *right = create_implicit_cast(*right, type_left);
 902                 return;
 903         }
 904
 905         if (is_type_compound(type_left)
 906                         && types_compatible(type_left, type_right)) {
 907                 *right = create_implicit_cast(*right, type_left);
 908                 return;
 909         }
 910
 911 incompatible_assign_types:
 912         /* TODO: improve error message */
 913         parser_print_error_prefix();
 914         fprintf(stderr, "incompatible types in %s\n", context);
 915         parser_print_error_prefix();
 916         print_type_quoted(orig_type_left);
 917         fputs(" <- ", stderr);
 918         print_type_quoted(orig_type_right);
 919         fputs("\n", stderr);
 920 }
 921
 922 static expression_t *parse_constant_expression(void)
 923 {
 924         /* start parsing at precedence 7 (conditional expression) */
 925         expression_t *result = parse_sub_expression(7);
 926
 927         if(!is_constant_expression(result)) {
 928                 parser_print_error_prefix_pos(result->base.source_position);
 929                 fprintf(stderr, "expression '");
 930                 print_expression(result);
 931                 fprintf(stderr, "' is not constant\n");
 932         }
 933
 934         return result;
 935 }
 936
 937 static expression_t *parse_assignment_expression(void)
 938 {
 939         /* start parsing at precedence 2 (assignment expression) */
 940         return parse_sub_expression(2);
 941 }
 942
 943 static type_t *make_global_typedef(const char *name, type_t *type)
 944 {
 945         symbol_t *symbol       = symbol_table_insert(name);
 946
 947         declaration_t *declaration   = allocate_ast_zero(sizeof(declaration[0]));
 948         declaration->namespc         = NAMESPACE_NORMAL;
 949         declaration->storage_class   = STORAGE_CLASS_TYPEDEF;
 950         declaration->type            = type;
 951         declaration->symbol          = symbol;
 952         declaration->source_position = builtin_source_position;
 953
 954         record_declaration(declaration);
 955
 956         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF);
 957         typedef_type->typedeft.declaration = declaration;
 958
 959         return typedef_type;
 960 }
 961
 962 static const char *parse_string_literals(void)
 963 {
 964         assert(token.type == T_STRING_LITERAL);
 965         const char *result = token.v.string;
 966
 967         next_token();
 968
 969         while(token.type == T_STRING_LITERAL) {
 970                 result = concat_strings(result, token.v.string);
 971                 next_token();
 972         }
 973
 974         return result;
 975 }
 976
 977 static void parse_attributes(void)
 978 {
 979         while(true) {
 980                 switch(token.type) {
 981                 case T___attribute__: {
 982                         next_token();
 983
 984                         expect_void('(');
 985                         int depth = 1;
 986                         while(depth > 0) {
 987                                 switch(token.type) {
 988                                 case T_EOF:
 989                                         parse_error("EOF while parsing attribute");
 990                                         break;
 991                                 case '(':
 992                                         next_token();
 993                                         depth++;
 994                                         break;
 995                                 case ')':
 996                                         next_token();
 997                                         depth--;
 998                                         break;
 999                                 default:
1000                                         next_token();
1001                                 }
1002                         }
1003                         break;
1004                 }
1005                 case T_asm:
1006                         next_token();
1007                         expect_void('(');
1008                         if(token.type != T_STRING_LITERAL) {
1009                                 parse_error_expected("while parsing assembler attribute",
1010                                                      T_STRING_LITERAL);
1011                                 eat_paren();
1012                                 break;
1013                         } else {
1014                                 parse_string_literals();
1015                         }
1016                         expect_void(')');
1017                         break;
1018                 default:
1019                         goto attributes_finished;
1020                 }
1021         }
1022
1023 attributes_finished:
1024         ;
1025 }
1026
1027 #if 0
1028 static designator_t *parse_designation(void)
1029 {
1030         if(token.type != '[' && token.type != '.')
1031                 return NULL;
1032
1033         designator_t *result = NULL;
1034         designator_t *last   = NULL;
1035
1036         while(1) {
1037                 designator_t *designator;
1038                 switch(token.type) {
1039                 case '[':
1040                         designator = allocate_ast_zero(sizeof(designator[0]));
1041                         next_token();
1042                         designator->array_access = parse_constant_expression();
1043                         expect(']');
1044                         break;
1045                 case '.':
1046                         designator = allocate_ast_zero(sizeof(designator[0]));
1047                         next_token();
1048                         if(token.type != T_IDENTIFIER) {
1049                                 parse_error_expected("while parsing designator",
1050                                                      T_IDENTIFIER, 0);
1051                                 return NULL;
1052                         }
1053                         designator->symbol = token.v.symbol;
1054                         next_token();
1055                         break;
1056                 default:
1057                         expect('=');
1058                         return result;
1059                 }
1060
1061                 assert(designator != NULL);
1062                 if(last != NULL) {
1063                         last->next = designator;
1064                 } else {
1065                         result = designator;
1066                 }
1067                 last = designator;
1068         }
1069 }
1070 #endif
1071
1072 static initializer_t *initializer_from_string(array_type_t *type,
1073                                               const char *string)
1074 {
1075         /* TODO: check len vs. size of array type */
1076         (void) type;
1077
1078         initializer_t *initializer = allocate_initializer(INITIALIZER_STRING);
1079         initializer->string.string = string;
1080
1081         return initializer;
1082 }
1083
1084 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1085                                                    wide_string_t *const string)
1086 {
1087         /* TODO: check len vs. size of array type */
1088         (void) type;
1089
1090         initializer_t *const initializer =
1091                 allocate_initializer(INITIALIZER_WIDE_STRING);
1092         initializer->wide_string.string = *string;
1093
1094         return initializer;
1095 }
1096
1097 static initializer_t *initializer_from_expression(type_t *type,
1098                                                   expression_t *expression)
1099 {
1100         /* TODO check that expression is a constant expression */
1101
1102         /* § 6.7.8.14/15 char array may be initialized by string literals */
1103         type_t *const expr_type = expression->base.datatype;
1104         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1105                 array_type_t *const array_type     = &type->array;
1106                 type_t       *const element_type   = skip_typeref(array_type->element_type);
1107
1108                 if (element_type->kind == TYPE_ATOMIC) {
1109                         switch (expression->kind) {
1110                                 case EXPR_STRING_LITERAL:
1111                                         if (element_type->atomic.atype == ATOMIC_TYPE_CHAR) {
1112                                                 return initializer_from_string(array_type,
1113                                                         expression->string.value);
1114                                         }
1115
1116                                 case EXPR_WIDE_STRING_LITERAL: {
1117                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1118                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1119                                                 return initializer_from_wide_string(array_type,
1120                                                         &expression->wide_string.value);
1121                                         }
1122                                 }
1123
1124                                 default: break;
1125                         }
1126                 }
1127         }
1128
1129         type_t *expression_type = skip_typeref(expression->base.datatype);
1130         if(is_type_scalar(type) || types_compatible(type, expression_type)) {
1131                 semantic_assign(type, &expression, "initializer");
1132
1133                 initializer_t *result = allocate_initializer(INITIALIZER_VALUE);
1134                 result->value.value   = expression;
1135
1136                 return result;
1137         }
1138
1139         return NULL;
1140 }
1141
1142 static initializer_t *parse_sub_initializer(type_t *type,
1143                                             expression_t *expression,
1144                                             type_t *expression_type);
1145
1146 static initializer_t *parse_sub_initializer_elem(type_t *type)
1147 {
1148         if(token.type == '{') {
1149                 return parse_sub_initializer(type, NULL, NULL);
1150         }
1151
1152         expression_t *expression      = parse_assignment_expression();
1153         type_t       *expression_type = skip_typeref(expression->base.datatype);
1154
1155         return parse_sub_initializer(type, expression, expression_type);
1156 }
1157
1158 static bool had_initializer_brace_warning;
1159
1160 static initializer_t *parse_sub_initializer(type_t *type,
1161                                             expression_t *expression,
1162                                             type_t *expression_type)
1163 {
1164         if(is_type_scalar(type)) {
1165                 /* there might be extra {} hierarchies */
1166                 if(token.type == '{') {
1167                         next_token();
1168                         if(!had_initializer_brace_warning) {
1169                                 parse_warning("braces around scalar initializer");
1170                                 had_initializer_brace_warning = true;
1171                         }
1172                         initializer_t *result = parse_sub_initializer(type, NULL, NULL);
1173                         if(token.type == ',') {
1174                                 next_token();
1175                                 /* TODO: warn about excessive elements */
1176                         }
1177                         expect_block('}');
1178                         return result;
1179                 }
1180
1181                 if(expression == NULL) {
1182                         expression = parse_assignment_expression();
1183                 }
1184                 return initializer_from_expression(type, expression);
1185         }
1186
1187         /* does the expression match the currently looked at object to initalize */
1188         if(expression != NULL) {
1189                 initializer_t *result = initializer_from_expression(type, expression);
1190                 if(result != NULL)
1191                         return result;
1192         }
1193
1194         bool read_paren = false;
1195         if(token.type == '{') {
1196                 next_token();
1197                 read_paren = true;
1198         }
1199
1200         /* descend into subtype */
1201         initializer_t  *result = NULL;
1202         initializer_t **elems;
1203         if(is_type_array(type)) {
1204                 array_type_t *array_type   = &type->array;
1205                 type_t       *element_type = array_type->element_type;
1206                 element_type               = skip_typeref(element_type);
1207
1208                 initializer_t *sub;
1209                 had_initializer_brace_warning = false;
1210                 if(expression == NULL) {
1211                         sub = parse_sub_initializer_elem(element_type);
1212                 } else {
1213                         sub = parse_sub_initializer(element_type, expression,
1214                                                     expression_type);
1215                 }
1216
1217                 /* didn't match the subtypes -> try the parent type */
1218                 if(sub == NULL) {
1219                         assert(!read_paren);
1220                         return NULL;
1221                 }
1222
1223                 elems = NEW_ARR_F(initializer_t*, 0);
1224                 ARR_APP1(initializer_t*, elems, sub);
1225
1226                 while(true) {
1227                         if(token.type == '}')
1228                                 break;
1229                         expect_block(',');
1230                         if(token.type == '}')
1231                                 break;
1232
1233                         sub = parse_sub_initializer_elem(element_type);
1234                         if(sub == NULL) {
1235                                 /* TODO error, do nicer cleanup */
1236                                 parse_error("member initializer didn't match");
1237                                 DEL_ARR_F(elems);
1238                                 return NULL;
1239                         }
1240                         ARR_APP1(initializer_t*, elems, sub);
1241                 }
1242         } else {
1243                 assert(is_type_compound(type));
1244                 compound_type_t *compound_type = &type->compound;
1245                 context_t       *context       = &compound_type->declaration->context;
1246
1247                 declaration_t *first = context->declarations;
1248                 if(first == NULL)
1249                         return NULL;
1250                 type_t *first_type = first->type;
1251                 first_type         = skip_typeref(first_type);
1252
1253                 initializer_t *sub;
1254                 had_initializer_brace_warning = false;
1255                 if(expression == NULL) {
1256                         sub = parse_sub_initializer_elem(first_type);
1257                 } else {
1258                         sub = parse_sub_initializer(first_type, expression,expression_type);
1259                 }
1260
1261                 /* didn't match the subtypes -> try our parent type */
1262                 if(sub == NULL) {
1263                         assert(!read_paren);
1264                         return NULL;
1265                 }
1266
1267                 elems = NEW_ARR_F(initializer_t*, 0);
1268                 ARR_APP1(initializer_t*, elems, sub);
1269
1270                 declaration_t *iter  = first->next;
1271                 for( ; iter != NULL; iter = iter->next) {
1272                         if(iter->symbol == NULL)
1273                                 continue;
1274                         if(iter->namespc != NAMESPACE_NORMAL)
1275                                 continue;
1276
1277                         if(token.type == '}')
1278                                 break;
1279                         expect_block(',');
1280                         if(token.type == '}')
1281                                 break;
1282
1283                         type_t *iter_type = iter->type;
1284                         iter_type         = skip_typeref(iter_type);
1285
1286                         sub = parse_sub_initializer_elem(iter_type);
1287                         if(sub == NULL) {
1288                                 /* TODO error, do nicer cleanup*/
1289                                 parse_error("member initializer didn't match");
1290                                 DEL_ARR_F(elems);
1291                                 return NULL;
1292                         }
1293                         ARR_APP1(initializer_t*, elems, sub);
1294                 }
1295         }
1296
1297         int    len        = ARR_LEN(elems);
1298         size_t elems_size = sizeof(initializer_t*) * len;
1299
1300         initializer_list_t *init = allocate_ast_zero(sizeof(init[0]) + elems_size);
1301
1302         init->initializer.kind = INITIALIZER_LIST;
1303         init->len              = len;
1304         memcpy(init->initializers, elems, elems_size);
1305         DEL_ARR_F(elems);
1306
1307         result = (initializer_t*) init;
1308
1309         if(read_paren) {
1310                 if(token.type == ',')
1311                         next_token();
1312                 expect('}');
1313         }
1314         return result;
1315 }
1316
1317 static initializer_t *parse_initializer(type_t *type)
1318 {
1319         initializer_t *result;
1320
1321         type = skip_typeref(type);
1322
1323         if(token.type != '{') {
1324                 expression_t  *expression  = parse_assignment_expression();
1325                 initializer_t *initializer = initializer_from_expression(type, expression);
1326                 if(initializer == NULL) {
1327                         parser_print_error_prefix();
1328                         fprintf(stderr, "initializer expression '");
1329                         print_expression(expression);
1330                         fprintf(stderr, "', type ");
1331                         print_type_quoted(expression->base.datatype);
1332                         fprintf(stderr, " is incompatible with type ");
1333                         print_type_quoted(type);
1334                         fprintf(stderr, "\n");
1335                 }
1336                 return initializer;
1337         }
1338
1339         if(is_type_scalar(type)) {
1340                 /* § 6.7.8.11 */
1341                 eat('{');
1342
1343                 expression_t *expression = parse_assignment_expression();
1344                 result = initializer_from_expression(type, expression);
1345
1346                 if(token.type == ',')
1347                         next_token();
1348
1349                 expect('}');
1350                 return result;
1351         } else {
1352                 result = parse_sub_initializer(type, NULL, NULL);
1353         }
1354
1355         return result;
1356 }
1357
1358
1359
1360 static declaration_t *parse_compound_type_specifier(bool is_struct)
1361 {
1362         if(is_struct) {
1363                 eat(T_struct);
1364         } else {
1365                 eat(T_union);
1366         }
1367
1368         symbol_t      *symbol      = NULL;
1369         declaration_t *declaration = NULL;
1370
1371         if (token.type == T___attribute__) {
1372                 /* TODO */
1373                 parse_attributes();
1374         }
1375
1376         if(token.type == T_IDENTIFIER) {
1377                 symbol = token.v.symbol;
1378                 next_token();
1379
1380                 if(is_struct) {
1381                         declaration = get_declaration(symbol, NAMESPACE_STRUCT);
1382                 } else {
1383                         declaration = get_declaration(symbol, NAMESPACE_UNION);
1384                 }
1385         } else if(token.type != '{') {
1386                 if(is_struct) {
1387                         parse_error_expected("while parsing struct type specifier",
1388                                              T_IDENTIFIER, '{', 0);
1389                 } else {
1390                         parse_error_expected("while parsing union type specifier",
1391                                              T_IDENTIFIER, '{', 0);
1392                 }
1393
1394                 return NULL;
1395         }
1396
1397         if(declaration == NULL) {
1398                 declaration = allocate_ast_zero(sizeof(declaration[0]));
1399
1400                 if(is_struct) {
1401                         declaration->namespc = NAMESPACE_STRUCT;
1402                 } else {
1403                         declaration->namespc = NAMESPACE_UNION;
1404                 }
1405                 declaration->source_position = token.source_position;
1406                 declaration->symbol          = symbol;
1407                 record_declaration(declaration);
1408         }
1409
1410         if(token.type == '{') {
1411                 if(declaration->init.is_defined) {
1412                         assert(symbol != NULL);
1413                         parser_print_error_prefix();
1414                         fprintf(stderr, "multiple definition of %s %s\n",
1415                                         is_struct ? "struct" : "union", symbol->string);
1416                         declaration->context.declarations = NULL;
1417                 }
1418                 declaration->init.is_defined = true;
1419
1420                 int         top          = environment_top();
1421                 context_t  *last_context = context;
1422                 set_context(&declaration->context);
1423
1424                 parse_compound_type_entries();
1425                 parse_attributes();
1426
1427                 assert(context == &declaration->context);
1428                 set_context(last_context);
1429                 environment_pop_to(top);
1430         }
1431
1432         return declaration;
1433 }
1434
1435 static void parse_enum_entries(enum_type_t *const enum_type)
1436 {
1437         eat('{');
1438
1439         if(token.type == '}') {
1440                 next_token();
1441                 parse_error("empty enum not allowed");
1442                 return;
1443         }
1444
1445         do {
1446                 declaration_t *entry = allocate_ast_zero(sizeof(entry[0]));
1447
1448                 if(token.type != T_IDENTIFIER) {
1449                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, 0);
1450                         eat_block();
1451                         return;
1452                 }
1453                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
1454                 entry->type            = (type_t*) enum_type;
1455                 entry->symbol          = token.v.symbol;
1456                 entry->source_position = token.source_position;
1457                 next_token();
1458
1459                 if(token.type == '=') {
1460                         next_token();
1461                         entry->init.enum_value = parse_constant_expression();
1462
1463                         /* TODO semantic */
1464                 }
1465
1466                 record_declaration(entry);
1467
1468                 if(token.type != ',')
1469                         break;
1470                 next_token();
1471         } while(token.type != '}');
1472
1473         expect_void('}');
1474 }
1475
1476 static type_t *parse_enum_specifier(void)
1477 {
1478         eat(T_enum);
1479
1480         declaration_t *declaration;
1481         symbol_t      *symbol;
1482
1483         if(token.type == T_IDENTIFIER) {
1484                 symbol = token.v.symbol;
1485                 next_token();
1486
1487                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1488         } else if(token.type != '{') {
1489                 parse_error_expected("while parsing enum type specifier",
1490                                      T_IDENTIFIER, '{', 0);
1491                 return NULL;
1492         } else {
1493                 declaration = NULL;
1494                 symbol      = NULL;
1495         }
1496
1497         if(declaration == NULL) {
1498                 declaration = allocate_ast_zero(sizeof(declaration[0]));
1499
1500                 declaration->namespc       = NAMESPACE_ENUM;
1501                 declaration->source_position = token.source_position;
1502                 declaration->symbol          = symbol;
1503         }
1504
1505         type_t *const type      = allocate_type_zero(TYPE_ENUM);
1506         type->enumt.declaration = declaration;
1507
1508         if(token.type == '{') {
1509                 if(declaration->init.is_defined) {
1510                         parser_print_error_prefix();
1511                         fprintf(stderr, "multiple definitions of enum %s\n",
1512                                 symbol->string);
1513                 }
1514                 record_declaration(declaration);
1515                 declaration->init.is_defined = 1;
1516
1517                 parse_enum_entries(&type->enumt);
1518                 parse_attributes();
1519         }
1520
1521         return type;
1522 }
1523
1524 /**
1525  * if a symbol is a typedef to another type, return true
1526  */
1527 static bool is_typedef_symbol(symbol_t *symbol)
1528 {
1529         const declaration_t *const declaration =
1530                 get_declaration(symbol, NAMESPACE_NORMAL);
1531         return
1532                 declaration != NULL &&
1533                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1534 }
1535
1536 static type_t *parse_typeof(void)
1537 {
1538         eat(T___typeof__);
1539
1540         type_t *type;
1541
1542         expect('(');
1543
1544         expression_t *expression  = NULL;
1545
1546 restart:
1547         switch(token.type) {
1548         case T___extension__:
1549                 /* this can be a prefix to a typename or an expression */
1550                 /* we simply eat it now. */
1551                 do {
1552                         next_token();
1553                 } while(token.type == T___extension__);
1554                 goto restart;
1555
1556         case T_IDENTIFIER:
1557                 if(is_typedef_symbol(token.v.symbol)) {
1558                         type = parse_typename();
1559                 } else {
1560                         expression = parse_expression();
1561                         type       = expression->base.datatype;
1562                 }
1563                 break;
1564
1565         TYPENAME_START
1566                 type = parse_typename();
1567                 break;
1568
1569         default:
1570                 expression = parse_expression();
1571                 type       = expression->base.datatype;
1572                 break;
1573         }
1574
1575         expect(')');
1576
1577         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
1578         typeof_type->typeoft.expression  = expression;
1579         typeof_type->typeoft.typeof_type = type;
1580
1581         return typeof_type;
1582 }
1583
1584 typedef enum {
1585         SPECIFIER_SIGNED    = 1 << 0,
1586         SPECIFIER_UNSIGNED  = 1 << 1,
1587         SPECIFIER_LONG      = 1 << 2,
1588         SPECIFIER_INT       = 1 << 3,
1589         SPECIFIER_DOUBLE    = 1 << 4,
1590         SPECIFIER_CHAR      = 1 << 5,
1591         SPECIFIER_SHORT     = 1 << 6,
1592         SPECIFIER_LONG_LONG = 1 << 7,
1593         SPECIFIER_FLOAT     = 1 << 8,
1594         SPECIFIER_BOOL      = 1 << 9,
1595         SPECIFIER_VOID      = 1 << 10,
1596 #ifdef PROVIDE_COMPLEX
1597         SPECIFIER_COMPLEX   = 1 << 11,
1598         SPECIFIER_IMAGINARY = 1 << 12,
1599 #endif
1600 } specifiers_t;
1601
1602 static type_t *create_builtin_type(symbol_t *const symbol,
1603                                    type_t *const real_type)
1604 {
1605         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
1606         type->builtin.symbol    = symbol;
1607         type->builtin.real_type = real_type;
1608
1609         type_t *result = typehash_insert(type);
1610         if (type != result) {
1611                 free_type(type);
1612         }
1613
1614         return result;
1615 }
1616
1617 static type_t *get_typedef_type(symbol_t *symbol)
1618 {
1619         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1620         if(declaration == NULL
1621                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1622                 return NULL;
1623
1624         type_t *type               = allocate_type_zero(TYPE_TYPEDEF);
1625         type->typedeft.declaration = declaration;
1626
1627         return type;
1628 }
1629
1630 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1631 {
1632         type_t   *type            = NULL;
1633         unsigned  type_qualifiers = 0;
1634         unsigned  type_specifiers = 0;
1635         int       newtype         = 0;
1636
1637         specifiers->source_position = token.source_position;
1638
1639         while(true) {
1640                 switch(token.type) {
1641
1642                 /* storage class */
1643 #define MATCH_STORAGE_CLASS(token, class)                                \
1644                 case token:                                                      \
1645                         if(specifiers->storage_class != STORAGE_CLASS_NONE) {        \
1646                                 parse_error("multiple storage classes in declaration "   \
1647                                             "specifiers");                               \
1648                         }                                                            \
1649                         specifiers->storage_class = class;                           \
1650                         next_token();                                                \
1651                         break;
1652
1653                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1654                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1655                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1656                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1657                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1658
1659                 case T___thread:
1660                         switch (specifiers->storage_class) {
1661                                 case STORAGE_CLASS_NONE:
1662                                         specifiers->storage_class = STORAGE_CLASS_THREAD;
1663                                         break;
1664
1665                                 case STORAGE_CLASS_EXTERN:
1666                                         specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
1667                                         break;
1668
1669                                 case STORAGE_CLASS_STATIC:
1670                                         specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
1671                                         break;
1672
1673                                 default:
1674                                         parse_error("multiple storage classes in declaration specifiers");
1675                                         break;
1676                         }
1677                         next_token();
1678                         break;
1679
1680                 /* type qualifiers */
1681 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1682                 case token:                                                     \
1683                         type_qualifiers |= qualifier;                               \
1684                         next_token();                                               \
1685                         break;
1686
1687                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1688                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1689                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1690
1691                 case T___extension__:
1692                         /* TODO */
1693                         next_token();
1694                         break;
1695
1696                 /* type specifiers */
1697 #define MATCH_SPECIFIER(token, specifier, name)                         \
1698                 case token:                                                     \
1699                         next_token();                                               \
1700                         if(type_specifiers & specifier) {                           \
1701                                 parse_error("multiple " name " type specifiers given"); \
1702                         } else {                                                    \
1703                                 type_specifiers |= specifier;                           \
1704                         }                                                           \
1705                         break;
1706
1707                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
1708                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
1709                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
1710                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
1711                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
1712                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
1713                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
1714                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
1715                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
1716 #ifdef PROVIDE_COMPLEX
1717                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
1718                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
1719 #endif
1720                 case T_forceinline:
1721                         /* only in microsoft mode */
1722                         specifiers->decl_modifiers |= DM_FORCEINLINE;
1723
1724                 case T_inline:
1725                         next_token();
1726                         specifiers->is_inline = true;
1727                         break;
1728
1729                 case T_long:
1730                         next_token();
1731                         if(type_specifiers & SPECIFIER_LONG_LONG) {
1732                                 parse_error("multiple type specifiers given");
1733                         } else if(type_specifiers & SPECIFIER_LONG) {
1734                                 type_specifiers |= SPECIFIER_LONG_LONG;
1735                         } else {
1736                                 type_specifiers |= SPECIFIER_LONG;
1737                         }
1738                         break;
1739
1740                 /* TODO: if type != NULL for the following rules should issue
1741                  * an error */
1742                 case T_struct: {
1743                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1744
1745                         type->compound.declaration = parse_compound_type_specifier(true);
1746                         break;
1747                 }
1748                 case T_union: {
1749                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1750
1751                         type->compound.declaration = parse_compound_type_specifier(false);
1752                         break;
1753                 }
1754                 case T_enum:
1755                         type = parse_enum_specifier();
1756                         break;
1757                 case T___typeof__:
1758                         type = parse_typeof();
1759                         break;
1760                 case T___builtin_va_list:
1761                         type = duplicate_type(type_valist);
1762                         next_token();
1763                         break;
1764
1765                 case T___attribute__:
1766                         /* TODO */
1767                         parse_attributes();
1768                         break;
1769
1770                 case T_IDENTIFIER: {
1771                         type_t *typedef_type = get_typedef_type(token.v.symbol);
1772
1773                         if(typedef_type == NULL)
1774                                 goto finish_specifiers;
1775
1776                         next_token();
1777                         type = typedef_type;
1778                         break;
1779                 }
1780
1781                 /* function specifier */
1782                 default:
1783                         goto finish_specifiers;
1784                 }
1785         }
1786
1787 finish_specifiers:
1788
1789         if(type == NULL) {
1790                 atomic_type_type_t atomic_type;
1791
1792                 /* match valid basic types */
1793                 switch(type_specifiers) {
1794                 case SPECIFIER_VOID:
1795                         atomic_type = ATOMIC_TYPE_VOID;
1796                         break;
1797                 case SPECIFIER_CHAR:
1798                         atomic_type = ATOMIC_TYPE_CHAR;
1799                         break;
1800                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
1801                         atomic_type = ATOMIC_TYPE_SCHAR;
1802                         break;
1803                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
1804                         atomic_type = ATOMIC_TYPE_UCHAR;
1805                         break;
1806                 case SPECIFIER_SHORT:
1807                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
1808                 case SPECIFIER_SHORT | SPECIFIER_INT:
1809                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1810                         atomic_type = ATOMIC_TYPE_SHORT;
1811                         break;
1812                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
1813                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1814                         atomic_type = ATOMIC_TYPE_USHORT;
1815                         break;
1816                 case SPECIFIER_INT:
1817                 case SPECIFIER_SIGNED:
1818                 case SPECIFIER_SIGNED | SPECIFIER_INT:
1819                         atomic_type = ATOMIC_TYPE_INT;
1820                         break;
1821                 case SPECIFIER_UNSIGNED:
1822                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
1823                         atomic_type = ATOMIC_TYPE_UINT;
1824                         break;
1825                 case SPECIFIER_LONG:
1826                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
1827                 case SPECIFIER_LONG | SPECIFIER_INT:
1828                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1829                         atomic_type = ATOMIC_TYPE_LONG;
1830                         break;
1831                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
1832                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1833                         atomic_type = ATOMIC_TYPE_ULONG;
1834                         break;
1835                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1836                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1837                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
1838                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1839                         | SPECIFIER_INT:
1840                         atomic_type = ATOMIC_TYPE_LONGLONG;
1841                         break;
1842                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1843                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1844                         | SPECIFIER_INT:
1845                         atomic_type = ATOMIC_TYPE_ULONGLONG;
1846                         break;
1847                 case SPECIFIER_FLOAT:
1848                         atomic_type = ATOMIC_TYPE_FLOAT;
1849                         break;
1850                 case SPECIFIER_DOUBLE:
1851                         atomic_type = ATOMIC_TYPE_DOUBLE;
1852                         break;
1853                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
1854                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
1855                         break;
1856                 case SPECIFIER_BOOL:
1857                         atomic_type = ATOMIC_TYPE_BOOL;
1858                         break;
1859 #ifdef PROVIDE_COMPLEX
1860                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
1861                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
1862                         break;
1863                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1864                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
1865                         break;
1866                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1867                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
1868                         break;
1869                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
1870                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
1871                         break;
1872                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1873                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
1874                         break;
1875                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1876                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
1877                         break;
1878 #endif
1879                 default:
1880                         /* invalid specifier combination, give an error message */
1881                         if(type_specifiers == 0) {
1882 #ifndef STRICT_C99
1883                                 parse_warning("no type specifiers in declaration, using int");
1884                                 atomic_type = ATOMIC_TYPE_INT;
1885                                 break;
1886 #else
1887                                 parse_error("no type specifiers given in declaration");
1888 #endif
1889                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
1890                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
1891                                 parse_error("signed and unsigned specifiers gives");
1892                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
1893                                 parse_error("only integer types can be signed or unsigned");
1894                         } else {
1895                                 parse_error("multiple datatypes in declaration");
1896                         }
1897                         atomic_type = ATOMIC_TYPE_INVALID;
1898                 }
1899
1900                 type               = allocate_type_zero(TYPE_ATOMIC);
1901                 type->atomic.atype = atomic_type;
1902                 newtype            = 1;
1903         } else {
1904                 if(type_specifiers != 0) {
1905                         parse_error("multiple datatypes in declaration");
1906                 }
1907         }
1908
1909         type->base.qualifiers = type_qualifiers;
1910
1911         type_t *result = typehash_insert(type);
1912         if(newtype && result != type) {
1913                 free_type(type);
1914         }
1915
1916         specifiers->type = result;
1917 }
1918
1919 static type_qualifiers_t parse_type_qualifiers(void)
1920 {
1921         type_qualifiers_t type_qualifiers = TYPE_QUALIFIER_NONE;
1922
1923         while(true) {
1924                 switch(token.type) {
1925                 /* type qualifiers */
1926                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1927                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1928                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1929
1930                 default:
1931                         return type_qualifiers;
1932                 }
1933         }
1934 }
1935
1936 static declaration_t *parse_identifier_list(void)
1937 {
1938         declaration_t *declarations     = NULL;
1939         declaration_t *last_declaration = NULL;
1940         do {
1941                 declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
1942
1943                 declaration->source_position = token.source_position;
1944                 declaration->symbol          = token.v.symbol;
1945                 next_token();
1946
1947                 if(last_declaration != NULL) {
1948                         last_declaration->next = declaration;
1949                 } else {
1950                         declarations = declaration;
1951                 }
1952                 last_declaration = declaration;
1953
1954                 if(token.type != ',')
1955                         break;
1956                 next_token();
1957         } while(token.type == T_IDENTIFIER);
1958
1959         return declarations;
1960 }
1961
1962 static void semantic_parameter(declaration_t *declaration)
1963 {
1964         /* TODO: improve error messages */
1965
1966         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
1967                 parse_error("typedef not allowed in parameter list");
1968         } else if(declaration->storage_class != STORAGE_CLASS_NONE
1969                         && declaration->storage_class != STORAGE_CLASS_REGISTER) {
1970                 parse_error("parameter may only have none or register storage class");
1971         }
1972
1973         type_t *orig_type = declaration->type;
1974         if(orig_type == NULL)
1975                 return;
1976         type_t *type = skip_typeref(orig_type);
1977
1978         /* Array as last part of a paramter type is just syntactic sugar.  Turn it
1979          * into a pointer. § 6.7.5.3 (7) */
1980         if (is_type_array(type)) {
1981                 const array_type_t *arr_type     = &type->array;
1982                 type_t             *element_type = arr_type->element_type;
1983
1984                 type = make_pointer_type(element_type, type->base.qualifiers);
1985
1986                 declaration->type = type;
1987         }
1988
1989         if(is_type_incomplete(type)) {
1990                 parser_print_error_prefix();
1991                 fprintf(stderr, "incomplete type (");
1992                 print_type_quoted(orig_type);
1993                 fprintf(stderr, ") not allowed for parameter '%s'\n",
1994                         declaration->symbol->string);
1995         }
1996 }
1997
1998 static declaration_t *parse_parameter(void)
1999 {
2000         declaration_specifiers_t specifiers;
2001         memset(&specifiers, 0, sizeof(specifiers));
2002
2003         parse_declaration_specifiers(&specifiers);
2004
2005         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
2006
2007         semantic_parameter(declaration);
2008
2009         return declaration;
2010 }
2011
2012 static declaration_t *parse_parameters(function_type_t *type)
2013 {
2014         if(token.type == T_IDENTIFIER) {
2015                 symbol_t *symbol = token.v.symbol;
2016                 if(!is_typedef_symbol(symbol)) {
2017                         type->kr_style_parameters = true;
2018                         return parse_identifier_list();
2019                 }
2020         }
2021
2022         if(token.type == ')') {
2023                 type->unspecified_parameters = 1;
2024                 return NULL;
2025         }
2026         if(token.type == T_void && look_ahead(1)->type == ')') {
2027                 next_token();
2028                 return NULL;
2029         }
2030
2031         declaration_t        *declarations = NULL;
2032         declaration_t        *declaration;
2033         declaration_t        *last_declaration = NULL;
2034         function_parameter_t *parameter;
2035         function_parameter_t *last_parameter = NULL;
2036
2037         while(true) {
2038                 switch(token.type) {
2039                 case T_DOTDOTDOT:
2040                         next_token();
2041                         type->variadic = 1;
2042                         return declarations;
2043
2044                 case T_IDENTIFIER:
2045                 case T___extension__:
2046                 DECLARATION_START
2047                         declaration = parse_parameter();
2048
2049                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
2050                         memset(parameter, 0, sizeof(parameter[0]));
2051                         parameter->type = declaration->type;
2052
2053                         if(last_parameter != NULL) {
2054                                 last_declaration->next = declaration;
2055                                 last_parameter->next   = parameter;
2056                         } else {
2057                                 type->parameters = parameter;
2058                                 declarations     = declaration;
2059                         }
2060                         last_parameter   = parameter;
2061                         last_declaration = declaration;
2062                         break;
2063
2064                 default:
2065                         return declarations;
2066                 }
2067                 if(token.type != ',')
2068                         return declarations;
2069                 next_token();
2070         }
2071 }
2072
2073 typedef enum {
2074         CONSTRUCT_INVALID,
2075         CONSTRUCT_POINTER,
2076         CONSTRUCT_FUNCTION,
2077         CONSTRUCT_ARRAY
2078 } construct_type_type_t;
2079
2080 typedef struct construct_type_t construct_type_t;
2081 struct construct_type_t {
2082         construct_type_type_t  type;
2083         construct_type_t      *next;
2084 };
2085
2086 typedef struct parsed_pointer_t parsed_pointer_t;
2087 struct parsed_pointer_t {
2088         construct_type_t  construct_type;
2089         type_qualifiers_t type_qualifiers;
2090 };
2091
2092 typedef struct construct_function_type_t construct_function_type_t;
2093 struct construct_function_type_t {
2094         construct_type_t  construct_type;
2095         type_t           *function_type;
2096 };
2097
2098 typedef struct parsed_array_t parsed_array_t;
2099 struct parsed_array_t {
2100         construct_type_t  construct_type;
2101         type_qualifiers_t type_qualifiers;
2102         bool              is_static;
2103         bool              is_variable;
2104         expression_t     *size;
2105 };
2106
2107 typedef struct construct_base_type_t construct_base_type_t;
2108 struct construct_base_type_t {
2109         construct_type_t  construct_type;
2110         type_t           *type;
2111 };
2112
2113 static construct_type_t *parse_pointer_declarator(void)
2114 {
2115         eat('*');
2116
2117         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
2118         memset(pointer, 0, sizeof(pointer[0]));
2119         pointer->construct_type.type = CONSTRUCT_POINTER;
2120         pointer->type_qualifiers     = parse_type_qualifiers();
2121
2122         return (construct_type_t*) pointer;
2123 }
2124
2125 static construct_type_t *parse_array_declarator(void)
2126 {
2127         eat('[');
2128
2129         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
2130         memset(array, 0, sizeof(array[0]));
2131         array->construct_type.type = CONSTRUCT_ARRAY;
2132
2133         if(token.type == T_static) {
2134                 array->is_static = true;
2135                 next_token();
2136         }
2137
2138         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
2139         if(type_qualifiers != 0) {
2140                 if(token.type == T_static) {
2141                         array->is_static = true;
2142                         next_token();
2143                 }
2144         }
2145         array->type_qualifiers = type_qualifiers;
2146
2147         if(token.type == '*' && look_ahead(1)->type == ']') {
2148                 array->is_variable = true;
2149                 next_token();
2150         } else if(token.type != ']') {
2151                 array->size = parse_assignment_expression();
2152         }
2153
2154         expect(']');
2155
2156         return (construct_type_t*) array;
2157 }
2158
2159 static construct_type_t *parse_function_declarator(declaration_t *declaration)
2160 {
2161         eat('(');
2162
2163         type_t *type = allocate_type_zero(TYPE_FUNCTION);
2164
2165         declaration_t *parameters = parse_parameters(&type->function);
2166         if(declaration != NULL) {
2167                 declaration->context.declarations = parameters;
2168         }
2169
2170         construct_function_type_t *construct_function_type =
2171                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
2172         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
2173         construct_function_type->construct_type.type = CONSTRUCT_FUNCTION;
2174         construct_function_type->function_type       = type;
2175
2176         expect(')');
2177
2178         return (construct_type_t*) construct_function_type;
2179 }
2180
2181 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
2182                 bool may_be_abstract)
2183 {
2184         /* construct a single linked list of construct_type_t's which describe
2185          * how to construct the final declarator type */
2186         construct_type_t *first = NULL;
2187         construct_type_t *last  = NULL;
2188
2189         /* pointers */
2190         while(token.type == '*') {
2191                 construct_type_t *type = parse_pointer_declarator();
2192
2193                 if(last == NULL) {
2194                         first = type;
2195                         last  = type;
2196                 } else {
2197                         last->next = type;
2198                         last       = type;
2199                 }
2200         }
2201
2202         /* TODO: find out if this is correct */
2203         parse_attributes();
2204
2205         construct_type_t *inner_types = NULL;
2206
2207         switch(token.type) {
2208         case T_IDENTIFIER:
2209                 if(declaration == NULL) {
2210                         parse_error("no identifier expected in typename");
2211                 } else {
2212                         declaration->symbol          = token.v.symbol;
2213                         declaration->source_position = token.source_position;
2214                 }
2215                 next_token();
2216                 break;
2217         case '(':
2218                 next_token();
2219                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
2220                 expect(')');
2221                 break;
2222         default:
2223                 if(may_be_abstract)
2224                         break;
2225                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
2226                 /* avoid a loop in the outermost scope, because eat_statement doesn't
2227                  * eat '}' */
2228                 if(token.type == '}' && current_function == NULL) {
2229                         next_token();
2230                 } else {
2231                         eat_statement();
2232                 }
2233                 return NULL;
2234         }
2235
2236         construct_type_t *p = last;
2237
2238         while(true) {
2239                 construct_type_t *type;
2240                 switch(token.type) {
2241                 case '(':
2242                         type = parse_function_declarator(declaration);
2243                         break;
2244                 case '[':
2245                         type = parse_array_declarator();
2246                         break;
2247                 default:
2248                         goto declarator_finished;
2249                 }
2250
2251                 /* insert in the middle of the list (behind p) */
2252                 if(p != NULL) {
2253                         type->next = p->next;
2254                         p->next    = type;
2255                 } else {
2256                         type->next = first;
2257                         first      = type;
2258                 }
2259                 if(last == p) {
2260                         last = type;
2261                 }
2262         }
2263
2264 declarator_finished:
2265         parse_attributes();
2266
2267         /* append inner_types at the end of the list, we don't to set last anymore
2268          * as it's not needed anymore */
2269         if(last == NULL) {
2270                 assert(first == NULL);
2271                 first = inner_types;
2272         } else {
2273                 last->next = inner_types;
2274         }
2275
2276         return first;
2277 }
2278
2279 static type_t *construct_declarator_type(construct_type_t *construct_list,
2280                                          type_t *type)
2281 {
2282         construct_type_t *iter = construct_list;
2283         for( ; iter != NULL; iter = iter->next) {
2284                 switch(iter->type) {
2285                 case CONSTRUCT_INVALID:
2286                         panic("invalid type construction found");
2287                 case CONSTRUCT_FUNCTION: {
2288                         construct_function_type_t *construct_function_type
2289                                 = (construct_function_type_t*) iter;
2290
2291                         type_t *function_type = construct_function_type->function_type;
2292
2293                         function_type->function.return_type = type;
2294
2295                         type = function_type;
2296                         break;
2297                 }
2298
2299                 case CONSTRUCT_POINTER: {
2300                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
2301                         type_t           *pointer_type   = allocate_type_zero(TYPE_POINTER);
2302                         pointer_type->pointer.points_to  = type;
2303                         pointer_type->base.qualifiers    = parsed_pointer->type_qualifiers;
2304
2305                         type = pointer_type;
2306                         break;
2307                 }
2308
2309                 case CONSTRUCT_ARRAY: {
2310                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
2311                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
2312
2313                         array_type->base.qualifiers    = parsed_array->type_qualifiers;
2314                         array_type->array.element_type = type;
2315                         array_type->array.is_static    = parsed_array->is_static;
2316                         array_type->array.is_variable  = parsed_array->is_variable;
2317                         array_type->array.size         = parsed_array->size;
2318
2319                         type = array_type;
2320                         break;
2321                 }
2322                 }
2323
2324                 type_t *hashed_type = typehash_insert(type);
2325                 if(hashed_type != type) {
2326                         /* the function type was constructed earlier freeing it here will
2327                          * destroy other types... */
2328                         if(iter->type != CONSTRUCT_FUNCTION) {
2329                                 free_type(type);
2330                         }
2331                         type = hashed_type;
2332                 }
2333         }
2334
2335         return type;
2336 }
2337
2338 static declaration_t *parse_declarator(
2339                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
2340 {
2341         type_t        *type         = specifiers->type;
2342         declaration_t *declaration  = allocate_ast_zero(sizeof(declaration[0]));
2343         declaration->storage_class  = specifiers->storage_class;
2344         declaration->decl_modifiers = specifiers->decl_modifiers;
2345         declaration->is_inline      = specifiers->is_inline;
2346
2347         construct_type_t *construct_type
2348                 = parse_inner_declarator(declaration, may_be_abstract);
2349         declaration->type = construct_declarator_type(construct_type, type);
2350
2351         if(construct_type != NULL) {
2352                 obstack_free(&temp_obst, construct_type);
2353         }
2354
2355         return declaration;
2356 }
2357
2358 static type_t *parse_abstract_declarator(type_t *base_type)
2359 {
2360         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2361
2362         type_t *result = construct_declarator_type(construct_type, base_type);
2363         if(construct_type != NULL) {
2364                 obstack_free(&temp_obst, construct_type);
2365         }
2366
2367         return result;
2368 }
2369
2370 static declaration_t *record_declaration(declaration_t *declaration)
2371 {
2372         assert(declaration->parent_context == NULL);
2373         assert(context != NULL);
2374
2375         symbol_t *symbol = declaration->symbol;
2376         if(symbol != NULL) {
2377                 declaration_t *alias = environment_push(declaration);
2378                 if(alias != declaration)
2379                         return alias;
2380         } else {
2381                 declaration->parent_context = context;
2382         }
2383
2384         if(last_declaration != NULL) {
2385                 last_declaration->next = declaration;
2386         } else {
2387                 context->declarations = declaration;
2388         }
2389         last_declaration = declaration;
2390
2391         return declaration;
2392 }
2393
2394 static void parser_error_multiple_definition(declaration_t *declaration,
2395                 const source_position_t source_position)
2396 {
2397         parser_print_error_prefix_pos(source_position);
2398         fprintf(stderr, "multiple definition of symbol '%s'\n",
2399                 declaration->symbol->string);
2400         parser_print_error_prefix_pos(declaration->source_position);
2401         fprintf(stderr, "this is the location of the previous definition.\n");
2402 }
2403
2404 static bool is_declaration_specifier(const token_t *token,
2405                                      bool only_type_specifiers)
2406 {
2407         switch(token->type) {
2408                 TYPE_SPECIFIERS
2409                         return true;
2410                 case T_IDENTIFIER:
2411                         return is_typedef_symbol(token->v.symbol);
2412
2413                 case T___extension__:
2414                 STORAGE_CLASSES
2415                 TYPE_QUALIFIERS
2416                         return !only_type_specifiers;
2417
2418                 default:
2419                         return false;
2420         }
2421 }
2422
2423 static void parse_init_declarator_rest(declaration_t *declaration)
2424 {
2425         eat('=');
2426
2427         type_t *orig_type = declaration->type;
2428         type_t *type      = NULL;
2429         if(orig_type != NULL)
2430                 type = skip_typeref(orig_type);
2431
2432         if(declaration->init.initializer != NULL) {
2433                 parser_error_multiple_definition(declaration, token.source_position);
2434         }
2435
2436         initializer_t *initializer = parse_initializer(type);
2437
2438         /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
2439          * the array type size */
2440         if(type != NULL && is_type_array(type) && initializer != NULL) {
2441                 array_type_t *array_type = &type->array;
2442
2443                 if(array_type->size == NULL) {
2444                         expression_t *cnst = allocate_expression_zero(EXPR_CONST);
2445
2446                         cnst->base.datatype = type_size_t;
2447
2448                         switch (initializer->kind) {
2449                                 case INITIALIZER_LIST: {
2450                                         initializer_list_t *const list = &initializer->list;
2451                                         cnst->conste.v.int_value = list->len;
2452                                         break;
2453                                 }
2454
2455                                 case INITIALIZER_STRING: {
2456                                         initializer_string_t *const string = &initializer->string;
2457                                         cnst->conste.v.int_value = strlen(string->string) + 1;
2458                                         break;
2459                                 }
2460
2461                                 case INITIALIZER_WIDE_STRING: {
2462                                         initializer_wide_string_t *const string = &initializer->wide_string;
2463                                         cnst->conste.v.int_value = string->string.size;
2464                                         break;
2465                                 }
2466
2467                                 default:
2468                                         panic("invalid initializer type");
2469                         }
2470
2471                         array_type->size = cnst;
2472                 }
2473         }
2474
2475         if(type != NULL && is_type_function(type)) {
2476                 parser_print_error_prefix_pos(declaration->source_position);
2477                 fprintf(stderr, "initializers not allowed for function types at "
2478                                 "declator '%s' (type ", declaration->symbol->string);
2479                 print_type_quoted(orig_type);
2480                 fprintf(stderr, ")\n");
2481         } else {
2482                 declaration->init.initializer = initializer;
2483         }
2484 }
2485
2486 /* parse rest of a declaration without any declarator */
2487 static void parse_anonymous_declaration_rest(
2488                 const declaration_specifiers_t *specifiers,
2489                 parsed_declaration_func finished_declaration)
2490 {
2491         eat(';');
2492
2493         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2494
2495         declaration->type            = specifiers->type;
2496         declaration->storage_class   = specifiers->storage_class;
2497         declaration->source_position = specifiers->source_position;
2498
2499         if (declaration->storage_class != STORAGE_CLASS_NONE) {
2500                 parse_warning_pos(declaration->source_position,
2501                                 "useless storage class in empty declaration");
2502         }
2503
2504         type_t *type = declaration->type;
2505         switch (type->kind) {
2506                 case TYPE_COMPOUND_STRUCT:
2507                 case TYPE_COMPOUND_UNION: {
2508                         const compound_type_t *compound_type = &type->compound;
2509                         if (compound_type->declaration->symbol == NULL) {
2510                                 parse_warning_pos(declaration->source_position,
2511                                                 "unnamed struct/union that defines no instances");
2512                         }
2513                         break;
2514                 }
2515
2516                 case TYPE_ENUM:
2517                         break;
2518
2519                 default:
2520                         parse_warning_pos(declaration->source_position,
2521                                           "empty declaration");
2522                         break;
2523         }
2524
2525         finished_declaration(declaration);
2526 }
2527
2528 static void parse_declaration_rest(declaration_t *ndeclaration,
2529                 const declaration_specifiers_t *specifiers,
2530                 parsed_declaration_func finished_declaration)
2531 {
2532         while(true) {
2533                 declaration_t *declaration = finished_declaration(ndeclaration);
2534
2535                 type_t *orig_type = declaration->type;
2536                 type_t *type      = skip_typeref(orig_type);
2537
2538                 if(type->kind != TYPE_FUNCTION && declaration->is_inline) {
2539                         parser_print_warning_prefix_pos(declaration->source_position);
2540                         fprintf(stderr, "variable '%s' declared 'inline'\n",
2541                                         declaration->symbol->string);
2542                 }
2543
2544                 if(token.type == '=') {
2545                         parse_init_declarator_rest(declaration);
2546                 }
2547
2548                 if(token.type != ',')
2549                         break;
2550                 eat(',');
2551
2552                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
2553         }
2554         expect_void(';');
2555 }
2556
2557 static declaration_t *finished_kr_declaration(declaration_t *declaration)
2558 {
2559         /* TODO: check that it was actually a parameter that gets a type */
2560
2561         /* we should have a declaration for the parameter in the current
2562          * scope */
2563         return record_declaration(declaration);
2564 }
2565
2566 static void parse_declaration(parsed_declaration_func finished_declaration)
2567 {
2568         declaration_specifiers_t specifiers;
2569         memset(&specifiers, 0, sizeof(specifiers));
2570         parse_declaration_specifiers(&specifiers);
2571
2572         if(token.type == ';') {
2573                 parse_anonymous_declaration_rest(&specifiers, finished_declaration);
2574         } else {
2575                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2576                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
2577         }
2578 }
2579
2580 static void parse_kr_declaration_list(declaration_t *declaration)
2581 {
2582         type_t *type = skip_typeref(declaration->type);
2583         if(!is_type_function(type))
2584                 return;
2585
2586         if(!type->function.kr_style_parameters)
2587                 return;
2588
2589         /* push function parameters */
2590         int         top          = environment_top();
2591         context_t  *last_context = context;
2592         set_context(&declaration->context);
2593
2594         declaration_t *parameter = declaration->context.declarations;
2595         for( ; parameter != NULL; parameter = parameter->next) {
2596                 environment_push(parameter);
2597         }
2598
2599         /* parse declaration list */
2600         while(is_declaration_specifier(&token, false)) {
2601                 parse_declaration(finished_kr_declaration);
2602         }
2603
2604         /* pop function parameters */
2605         assert(context == &declaration->context);
2606         set_context(last_context);
2607         environment_pop_to(top);
2608
2609         /* update function type */
2610         type_t *new_type = duplicate_type(type);
2611         new_type->function.kr_style_parameters = false;
2612
2613         function_parameter_t *parameters     = NULL;
2614         function_parameter_t *last_parameter = NULL;
2615
2616         declaration_t *parameter_declaration = declaration->context.declarations;
2617         for( ; parameter_declaration != NULL;
2618                         parameter_declaration = parameter_declaration->next) {
2619                 type_t *parameter_type = parameter_declaration->type;
2620                 if(parameter_type == NULL) {
2621 #ifdef STRICT_C99
2622                         parser_print_error_prefix();
2623                         fprintf(stderr, "no type specified for function parameter '%s'\n",
2624                                 parameter_declaration->symbol->string);
2625 #else
2626                         parser_print_warning_prefix();
2627                         fprintf(stderr, "no type specified for function parameter '%s', "
2628                                 "using int\n", parameter_declaration->symbol->string);
2629                         parameter_type              = type_int;
2630                         parameter_declaration->type = parameter_type;
2631 #endif
2632                 }
2633
2634                 semantic_parameter(parameter_declaration);
2635                 parameter_type = parameter_declaration->type;
2636
2637                 function_parameter_t *function_parameter
2638                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
2639                 memset(function_parameter, 0, sizeof(function_parameter[0]));
2640
2641                 function_parameter->type = parameter_type;
2642                 if(last_parameter != NULL) {
2643                         last_parameter->next = function_parameter;
2644                 } else {
2645                         parameters = function_parameter;
2646                 }
2647                 last_parameter = function_parameter;
2648         }
2649         new_type->function.parameters = parameters;
2650
2651         type = typehash_insert(new_type);
2652         if(type != new_type) {
2653                 obstack_free(type_obst, new_type);
2654         }
2655
2656         declaration->type = type;
2657 }
2658
2659 static void parse_external_declaration(void)
2660 {
2661         /* function-definitions and declarations both start with declaration
2662          * specifiers */
2663         declaration_specifiers_t specifiers;
2664         memset(&specifiers, 0, sizeof(specifiers));
2665         parse_declaration_specifiers(&specifiers);
2666
2667         /* must be a declaration */
2668         if(token.type == ';') {
2669                 parse_anonymous_declaration_rest(&specifiers, record_declaration);
2670                 return;
2671         }
2672
2673         /* declarator is common to both function-definitions and declarations */
2674         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2675
2676         /* must be a declaration */
2677         if(token.type == ',' || token.type == '=' || token.type == ';') {
2678                 parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
2679                 return;
2680         }
2681
2682         /* must be a function definition */
2683         parse_kr_declaration_list(ndeclaration);
2684
2685         if(token.type != '{') {
2686                 parse_error_expected("while parsing function definition", '{', 0);
2687                 eat_statement();
2688                 return;
2689         }
2690
2691         type_t *type = ndeclaration->type;
2692         if(type == NULL) {
2693                 eat_block();
2694                 return;
2695         }
2696
2697         /* note that we don't skip typerefs: the standard doesn't allow them here
2698          * (so we can't use is_type_function here) */
2699         if(type->kind != TYPE_FUNCTION) {
2700                 parser_print_error_prefix();
2701                 fprintf(stderr, "declarator '");
2702                 print_type_ext(type, ndeclaration->symbol, NULL);
2703                 fprintf(stderr, "' has a body but is not a function type.\n");
2704                 eat_block();
2705                 return;
2706         }
2707
2708         /* § 6.7.5.3 (14) a function definition with () means no
2709          * parameters (and not unspecified parameters) */
2710         if(type->function.unspecified_parameters) {
2711                 type_t *duplicate = duplicate_type(type);
2712                 duplicate->function.unspecified_parameters = false;
2713
2714                 type = typehash_insert(duplicate);
2715                 if(type != duplicate) {
2716                         obstack_free(type_obst, duplicate);
2717                 }
2718                 ndeclaration->type = type;
2719         }
2720
2721         declaration_t *declaration = record_declaration(ndeclaration);
2722         if(ndeclaration != declaration) {
2723                 memcpy(&declaration->context, &ndeclaration->context,
2724                                 sizeof(declaration->context));
2725         }
2726         type = skip_typeref(declaration->type);
2727
2728         /* push function parameters and switch context */
2729         int         top          = environment_top();
2730         context_t  *last_context = context;
2731         set_context(&declaration->context);
2732
2733         declaration_t *parameter = declaration->context.declarations;
2734         for( ; parameter != NULL; parameter = parameter->next) {
2735                 environment_push(parameter);
2736         }
2737
2738         if(declaration->init.statement != NULL) {
2739                 parser_error_multiple_definition(declaration, token.source_position);
2740                 eat_block();
2741                 goto end_of_parse_external_declaration;
2742         } else {
2743                 /* parse function body */
2744                 int            label_stack_top      = label_top();
2745                 declaration_t *old_current_function = current_function;
2746                 current_function                    = declaration;
2747
2748                 declaration->init.statement = parse_compound_statement();
2749
2750                 assert(current_function == declaration);
2751                 current_function = old_current_function;
2752                 label_pop_to(label_stack_top);
2753         }
2754
2755 end_of_parse_external_declaration:
2756         assert(context == &declaration->context);
2757         set_context(last_context);
2758         environment_pop_to(top);
2759 }
2760
2761 static void parse_struct_declarators(const declaration_specifiers_t *specifiers)
2762 {
2763         while(1) {
2764                 if(token.type == ':') {
2765                         next_token();
2766                         parse_constant_expression();
2767                         /* TODO (bitfields) */
2768                 } else {
2769                         declaration_t *declaration = parse_declarator(specifiers, /*may_be_abstract=*/true);
2770
2771                         /* TODO: check constraints for struct declarations */
2772                         /* TODO: check for doubled fields */
2773                         record_declaration(declaration);
2774
2775                         if(token.type == ':') {
2776                                 next_token();
2777                                 parse_constant_expression();
2778                                 /* TODO (bitfields) */
2779                         }
2780                 }
2781
2782                 if(token.type != ',')
2783                         break;
2784                 next_token();
2785         }
2786         expect_void(';');
2787 }
2788
2789 static void parse_compound_type_entries(void)
2790 {
2791         eat('{');
2792
2793         while(token.type != '}' && token.type != T_EOF) {
2794                 declaration_specifiers_t specifiers;
2795                 memset(&specifiers, 0, sizeof(specifiers));
2796                 parse_declaration_specifiers(&specifiers);
2797
2798                 parse_struct_declarators(&specifiers);
2799         }
2800         if(token.type == T_EOF) {
2801                 parse_error("EOF while parsing struct");
2802         }
2803         next_token();
2804 }
2805
2806 static type_t *parse_typename(void)
2807 {
2808         declaration_specifiers_t specifiers;
2809         memset(&specifiers, 0, sizeof(specifiers));
2810         parse_declaration_specifiers(&specifiers);
2811         if(specifiers.storage_class != STORAGE_CLASS_NONE) {
2812                 /* TODO: improve error message, user does probably not know what a
2813                  * storage class is...
2814                  */
2815                 parse_error("typename may not have a storage class");
2816         }
2817
2818         type_t *result = parse_abstract_declarator(specifiers.type);
2819
2820         return result;
2821 }
2822
2823
2824
2825
2826 typedef expression_t* (*parse_expression_function) (unsigned precedence);
2827 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
2828                                                           expression_t *left);
2829
2830 typedef struct expression_parser_function_t expression_parser_function_t;
2831 struct expression_parser_function_t {
2832         unsigned                         precedence;
2833         parse_expression_function        parser;
2834         unsigned                         infix_precedence;
2835         parse_expression_infix_function  infix_parser;
2836 };
2837
2838 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
2839
2840 static expression_t *create_invalid_expression(void)
2841 {
2842         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
2843         expression->base.source_position = token.source_position;
2844         return expression;
2845 }
2846
2847 static expression_t *expected_expression_error(void)
2848 {
2849         parser_print_error_prefix();
2850         fprintf(stderr, "expected expression, got token ");
2851         print_token(stderr, &token);
2852         fprintf(stderr, "\n");
2853
2854         next_token();
2855
2856         return create_invalid_expression();
2857 }
2858
2859 static expression_t *parse_string_const(void)
2860 {
2861         expression_t *cnst  = allocate_expression_zero(EXPR_STRING_LITERAL);
2862         cnst->base.datatype = type_string;
2863         cnst->string.value  = parse_string_literals();
2864
2865         return cnst;
2866 }
2867
2868 static expression_t *parse_wide_string_const(void)
2869 {
2870         expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
2871         cnst->base.datatype      = type_wchar_t_ptr;
2872         cnst->wide_string.value  = token.v.wide_string; /* TODO concatenate */
2873         next_token();
2874         return cnst;
2875 }
2876
2877 static expression_t *parse_int_const(void)
2878 {
2879         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2880         cnst->base.datatype      = token.datatype;
2881         cnst->conste.v.int_value = token.v.intvalue;
2882
2883         next_token();
2884
2885         return cnst;
2886 }
2887
2888 static expression_t *parse_float_const(void)
2889 {
2890         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
2891         cnst->base.datatype        = token.datatype;
2892         cnst->conste.v.float_value = token.v.floatvalue;
2893
2894         next_token();
2895
2896         return cnst;
2897 }
2898
2899 static declaration_t *create_implicit_function(symbol_t *symbol,
2900                 const source_position_t source_position)
2901 {
2902         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
2903         ntype->function.return_type            = type_int;
2904         ntype->function.unspecified_parameters = true;
2905
2906         type_t *type = typehash_insert(ntype);
2907         if(type != ntype) {
2908                 free_type(ntype);
2909         }
2910
2911         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2912
2913         declaration->storage_class   = STORAGE_CLASS_EXTERN;
2914         declaration->type            = type;
2915         declaration->symbol          = symbol;
2916         declaration->source_position = source_position;
2917
2918         /* prepend the implicit definition to the global context
2919          * this is safe since the symbol wasn't declared as anything else yet
2920          */
2921         assert(symbol->declaration == NULL);
2922
2923         context_t *last_context = context;
2924         context = global_context;
2925
2926         environment_push(declaration);
2927         declaration->next     = context->declarations;
2928         context->declarations = declaration;
2929
2930         context = last_context;
2931
2932         return declaration;
2933 }
2934
2935 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
2936 {
2937         function_parameter_t *parameter
2938                 = obstack_alloc(type_obst, sizeof(parameter[0]));
2939         memset(parameter, 0, sizeof(parameter[0]));
2940         parameter->type = argument_type;
2941
2942         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
2943         type->function.return_type = return_type;
2944         type->function.parameters  = parameter;
2945
2946         type_t *result = typehash_insert(type);
2947         if(result != type) {
2948                 free_type(type);
2949         }
2950
2951         return result;
2952 }
2953
2954 static type_t *get_builtin_symbol_type(symbol_t *symbol)
2955 {
2956         switch(symbol->ID) {
2957         case T___builtin_alloca:
2958                 return make_function_1_type(type_void_ptr, type_size_t);
2959         case T___builtin_nan:
2960                 return make_function_1_type(type_double, type_string);
2961         case T___builtin_nanf:
2962                 return make_function_1_type(type_float, type_string);
2963         case T___builtin_nand:
2964                 return make_function_1_type(type_long_double, type_string);
2965         case T___builtin_va_end:
2966                 return make_function_1_type(type_void, type_valist);
2967         default:
2968                 panic("not implemented builtin symbol found");
2969         }
2970 }
2971
2972 /**
2973  * performs automatic type cast as described in § 6.3.2.1
2974  */
2975 static type_t *automatic_type_conversion(type_t *orig_type)
2976 {
2977         if(orig_type == NULL)
2978                 return NULL;
2979
2980         type_t *type = skip_typeref(orig_type);
2981         if(is_type_array(type)) {
2982                 array_type_t *array_type   = &type->array;
2983                 type_t       *element_type = array_type->element_type;
2984                 unsigned      qualifiers   = array_type->type.qualifiers;
2985
2986                 return make_pointer_type(element_type, qualifiers);
2987         }
2988
2989         if(is_type_function(type)) {
2990                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
2991         }
2992
2993         return orig_type;
2994 }
2995
2996 /**
2997  * reverts the automatic casts of array to pointer types and function
2998  * to function-pointer types as defined § 6.3.2.1
2999  */
3000 type_t *revert_automatic_type_conversion(const expression_t *expression)
3001 {
3002         if(expression->base.datatype == NULL)
3003                 return NULL;
3004
3005         switch(expression->kind) {
3006         case EXPR_REFERENCE: {
3007                 const reference_expression_t *ref = &expression->reference;
3008                 return ref->declaration->type;
3009         }
3010         case EXPR_SELECT: {
3011                 const select_expression_t *select = &expression->select;
3012                 return select->compound_entry->type;
3013         }
3014         case EXPR_UNARY_DEREFERENCE: {
3015                 expression_t   *value        = expression->unary.value;
3016                 type_t         *type         = skip_typeref(value->base.datatype);
3017                 pointer_type_t *pointer_type = &type->pointer;
3018
3019                 return pointer_type->points_to;
3020         }
3021         case EXPR_BUILTIN_SYMBOL: {
3022                 const builtin_symbol_expression_t *builtin
3023                         = &expression->builtin_symbol;
3024                 return get_builtin_symbol_type(builtin->symbol);
3025         }
3026         case EXPR_ARRAY_ACCESS: {
3027                 const array_access_expression_t *array_access
3028                         = &expression->array_access;
3029                 const expression_t *array_ref = array_access->array_ref;
3030                 type_t *type_left  = skip_typeref(array_ref->base.datatype);
3031                 assert(is_type_pointer(type_left));
3032                 pointer_type_t *pointer_type = &type_left->pointer;
3033                 return pointer_type->points_to;
3034         }
3035
3036         default:
3037                 break;
3038         }
3039
3040         return expression->base.datatype;
3041 }
3042
3043 static expression_t *parse_reference(void)
3044 {
3045         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
3046
3047         reference_expression_t *ref = &expression->reference;
3048         ref->symbol = token.v.symbol;
3049
3050         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
3051
3052         source_position_t source_position = token.source_position;
3053         next_token();
3054
3055         if(declaration == NULL) {
3056 #ifndef STRICT_C99
3057                 /* an implicitly defined function */
3058                 if(token.type == '(') {
3059                         parser_print_prefix_pos(token.source_position);
3060                         fprintf(stderr, "warning: implicit declaration of function '%s'\n",
3061                                 ref->symbol->string);
3062
3063                         declaration = create_implicit_function(ref->symbol,
3064                                                                source_position);
3065                 } else
3066 #endif
3067                 {
3068                         parser_print_error_prefix();
3069                         fprintf(stderr, "unknown symbol '%s' found.\n", ref->symbol->string);
3070                         return expression;
3071                 }
3072         }
3073
3074         type_t *type = declaration->type;
3075         /* we always do the auto-type conversions; the & and sizeof parser contains
3076          * code to revert this! */
3077         type = automatic_type_conversion(type);
3078
3079         ref->declaration         = declaration;
3080         ref->expression.datatype = type;
3081
3082         return expression;
3083 }
3084
3085 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
3086 {
3087         (void) expression;
3088         (void) dest_type;
3089         /* TODO check if explicit cast is allowed and issue warnings/errors */
3090 }
3091
3092 static expression_t *parse_cast(void)
3093 {
3094         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
3095
3096         cast->base.source_position = token.source_position;
3097
3098         type_t *type  = parse_typename();
3099
3100         expect(')');
3101         expression_t *value = parse_sub_expression(20);
3102
3103         check_cast_allowed(value, type);
3104
3105         cast->base.datatype = type;
3106         cast->unary.value   = value;
3107
3108         return cast;
3109 }
3110
3111 static expression_t *parse_statement_expression(void)
3112 {
3113         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
3114
3115         statement_t *statement          = parse_compound_statement();
3116         expression->statement.statement = statement;
3117         if(statement == NULL) {
3118                 expect(')');
3119                 return NULL;
3120         }
3121
3122         assert(statement->kind == STATEMENT_COMPOUND);
3123         compound_statement_t *compound_statement = &statement->compound;
3124
3125         /* find last statement and use it's type */
3126         const statement_t *last_statement = NULL;
3127         const statement_t *iter           = compound_statement->statements;
3128         for( ; iter != NULL; iter = iter->base.next) {
3129                 last_statement = iter;
3130         }
3131
3132         if(last_statement->kind == STATEMENT_EXPRESSION) {
3133                 const expression_statement_t *expression_statement
3134                         = &last_statement->expression;
3135                 expression->base.datatype
3136                         = expression_statement->expression->base.datatype;
3137         } else {
3138                 expression->base.datatype = type_void;
3139         }
3140
3141         expect(')');
3142
3143         return expression;
3144 }
3145
3146 static expression_t *parse_brace_expression(void)
3147 {
3148         eat('(');
3149
3150         switch(token.type) {
3151         case '{':
3152                 /* gcc extension: a stement expression */
3153                 return parse_statement_expression();
3154
3155         TYPE_QUALIFIERS
3156         TYPE_SPECIFIERS
3157                 return parse_cast();
3158         case T_IDENTIFIER:
3159                 if(is_typedef_symbol(token.v.symbol)) {
3160                         return parse_cast();
3161                 }
3162         }
3163
3164         expression_t *result = parse_expression();
3165         expect(')');
3166
3167         return result;
3168 }
3169
3170 static expression_t *parse_function_keyword(void)
3171 {
3172         next_token();
3173         /* TODO */
3174
3175         if (current_function == NULL) {
3176                 parse_error("'__func__' used outside of a function");
3177         }
3178
3179         string_literal_expression_t *expression
3180                 = allocate_ast_zero(sizeof(expression[0]));
3181
3182         expression->expression.kind     = EXPR_FUNCTION;
3183         expression->expression.datatype = type_string;
3184         expression->value               = current_function->symbol->string;
3185
3186         return (expression_t*) expression;
3187 }
3188
3189 static expression_t *parse_pretty_function_keyword(void)
3190 {
3191         eat(T___PRETTY_FUNCTION__);
3192         /* TODO */
3193
3194         if (current_function == NULL) {
3195                 parse_error("'__PRETTY_FUNCTION__' used outside of a function");
3196         }
3197
3198         string_literal_expression_t *expression
3199                 = allocate_ast_zero(sizeof(expression[0]));
3200
3201         expression->expression.kind     = EXPR_PRETTY_FUNCTION;
3202         expression->expression.datatype = type_string;
3203         expression->value               = current_function->symbol->string;
3204
3205         return (expression_t*) expression;
3206 }
3207
3208 static designator_t *parse_designator(void)
3209 {
3210         designator_t *result = allocate_ast_zero(sizeof(result[0]));
3211
3212         if(token.type != T_IDENTIFIER) {
3213                 parse_error_expected("while parsing member designator",
3214                                      T_IDENTIFIER, 0);
3215                 eat_paren();
3216                 return NULL;
3217         }
3218         result->symbol = token.v.symbol;
3219         next_token();
3220
3221         designator_t *last_designator = result;
3222         while(true) {
3223                 if(token.type == '.') {
3224                         next_token();
3225                         if(token.type != T_IDENTIFIER) {
3226                                 parse_error_expected("while parsing member designator",
3227                                                      T_IDENTIFIER, 0);
3228                                 eat_paren();
3229                                 return NULL;
3230                         }
3231                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3232                         designator->symbol       = token.v.symbol;
3233                         next_token();
3234
3235                         last_designator->next = designator;
3236                         last_designator       = designator;
3237                         continue;
3238                 }
3239                 if(token.type == '[') {
3240                         next_token();
3241                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3242                         designator->array_access = parse_expression();
3243                         if(designator->array_access == NULL) {
3244                                 eat_paren();
3245                                 return NULL;
3246                         }
3247                         expect(']');
3248
3249                         last_designator->next = designator;
3250                         last_designator       = designator;
3251                         continue;
3252                 }
3253                 break;
3254         }
3255
3256         return result;
3257 }
3258
3259 static expression_t *parse_offsetof(void)
3260 {
3261         eat(T___builtin_offsetof);
3262
3263         expression_t *expression  = allocate_expression_zero(EXPR_OFFSETOF);
3264         expression->base.datatype = type_size_t;
3265
3266         expect('(');
3267         expression->offsetofe.type = parse_typename();
3268         expect(',');
3269         expression->offsetofe.designator = parse_designator();
3270         expect(')');
3271
3272         return expression;
3273 }
3274
3275 static expression_t *parse_va_start(void)
3276 {
3277         eat(T___builtin_va_start);
3278
3279         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
3280
3281         expect('(');
3282         expression->va_starte.ap = parse_assignment_expression();
3283         expect(',');
3284         expression_t *const expr = parse_assignment_expression();
3285         if (expr->kind == EXPR_REFERENCE) {
3286                 declaration_t *const decl = expr->reference.declaration;
3287                 if (decl->parent_context == &current_function->context &&
3288                     decl->next == NULL) {
3289                         expression->va_starte.parameter = decl;
3290                         expect(')');
3291                         return expression;
3292                 }
3293         }
3294         parser_print_error_prefix_pos(expr->base.source_position);
3295         fprintf(stderr, "second argument of 'va_start' must be last parameter "
3296                         "of the current function\n");
3297
3298         return create_invalid_expression();
3299 }
3300
3301 static expression_t *parse_va_arg(void)
3302 {
3303         eat(T___builtin_va_arg);
3304
3305         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
3306
3307         expect('(');
3308         expression->va_arge.ap = parse_assignment_expression();
3309         expect(',');
3310         expression->base.datatype = parse_typename();
3311         expect(')');
3312
3313         return expression;
3314 }
3315
3316 static expression_t *parse_builtin_symbol(void)
3317 {
3318         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
3319
3320         symbol_t *symbol = token.v.symbol;
3321
3322         expression->builtin_symbol.symbol = symbol;
3323         next_token();
3324
3325         type_t *type = get_builtin_symbol_type(symbol);
3326         type = automatic_type_conversion(type);
3327
3328         expression->base.datatype = type;
3329         return expression;
3330 }
3331
3332 static expression_t *parse_compare_builtin(void)
3333 {
3334         expression_t *expression;
3335
3336         switch(token.type) {
3337         case T___builtin_isgreater:
3338                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
3339                 break;
3340         case T___builtin_isgreaterequal:
3341                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
3342                 break;
3343         case T___builtin_isless:
3344                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
3345                 break;
3346         case T___builtin_islessequal:
3347                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
3348                 break;
3349         case T___builtin_islessgreater:
3350                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
3351                 break;
3352         case T___builtin_isunordered:
3353                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
3354                 break;
3355         default:
3356                 panic("invalid compare builtin found");
3357                 break;
3358         }
3359         next_token();
3360
3361         expect('(');
3362         expression->binary.left = parse_assignment_expression();
3363         expect(',');
3364         expression->binary.right = parse_assignment_expression();
3365         expect(')');
3366
3367         type_t *orig_type_left  = expression->binary.left->base.datatype;
3368         type_t *orig_type_right = expression->binary.right->base.datatype;
3369         if(orig_type_left == NULL || orig_type_right == NULL)
3370                 return expression;
3371
3372         type_t *type_left  = skip_typeref(orig_type_left);
3373         type_t *type_right = skip_typeref(orig_type_right);
3374         if(!is_type_floating(type_left) && !is_type_floating(type_right)) {
3375                 type_error_incompatible("invalid operands in comparison",
3376                                         token.source_position, type_left, type_right);
3377         } else {
3378                 semantic_comparison(&expression->binary);
3379         }
3380
3381         return expression;
3382 }
3383
3384 static expression_t *parse_builtin_expect(void)
3385 {
3386         eat(T___builtin_expect);
3387
3388         expression_t *expression
3389                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
3390
3391         expect('(');
3392         expression->binary.left = parse_assignment_expression();
3393         expect(',');
3394         expression->binary.right = parse_constant_expression();
3395         expect(')');
3396
3397         expression->base.datatype = expression->binary.left->base.datatype;
3398
3399         return expression;
3400 }
3401
3402 static expression_t *parse_assume(void) {
3403         eat(T_assume);
3404
3405         expression_t *expression
3406                 = allocate_expression_zero(EXPR_UNARY_ASSUME);
3407
3408         expect('(');
3409         expression->unary.value = parse_expression();
3410         expect(')');
3411
3412         expression->base.datatype = type_void;
3413         return expression;
3414 }
3415
3416 static expression_t *parse_primary_expression(void)
3417 {
3418         switch(token.type) {
3419         case T_INTEGER:
3420                 return parse_int_const();
3421         case T_FLOATINGPOINT:
3422                 return parse_float_const();
3423         case T_STRING_LITERAL: /* TODO merge */
3424                 return parse_string_const();
3425         case T_WIDE_STRING_LITERAL:
3426                 return parse_wide_string_const();
3427         case T_IDENTIFIER:
3428                 return parse_reference();
3429         case T___FUNCTION__:
3430         case T___func__:
3431                 return parse_function_keyword();
3432         case T___PRETTY_FUNCTION__:
3433                 return parse_pretty_function_keyword();
3434         case T___builtin_offsetof:
3435                 return parse_offsetof();
3436         case T___builtin_va_start:
3437                 return parse_va_start();
3438         case T___builtin_va_arg:
3439                 return parse_va_arg();
3440         case T___builtin_expect:
3441                 return parse_builtin_expect();
3442         case T___builtin_nanf:
3443         case T___builtin_alloca:
3444         case T___builtin_va_end:
3445                 return parse_builtin_symbol();
3446         case T___builtin_isgreater:
3447         case T___builtin_isgreaterequal:
3448         case T___builtin_isless:
3449         case T___builtin_islessequal:
3450         case T___builtin_islessgreater:
3451         case T___builtin_isunordered:
3452                 return parse_compare_builtin();
3453         case T_assume:
3454                 return parse_assume();
3455
3456         case '(':
3457                 return parse_brace_expression();
3458         }
3459
3460         parser_print_error_prefix();
3461         fprintf(stderr, "unexpected token ");
3462         print_token(stderr, &token);
3463         fprintf(stderr, "\n");
3464         eat_statement();
3465
3466         return create_invalid_expression();
3467 }
3468
3469 static expression_t *parse_array_expression(unsigned precedence,
3470                                             expression_t *left)
3471 {
3472         (void) precedence;
3473
3474         eat('[');
3475
3476         expression_t *inside = parse_expression();
3477
3478         array_access_expression_t *array_access
3479                 = allocate_ast_zero(sizeof(array_access[0]));
3480
3481         array_access->expression.kind = EXPR_ARRAY_ACCESS;
3482
3483         type_t *type_left   = left->base.datatype;
3484         type_t *type_inside = inside->base.datatype;
3485         type_t *return_type = NULL;
3486
3487         if(type_left != NULL && type_inside != NULL) {
3488                 type_left   = skip_typeref(type_left);
3489                 type_inside = skip_typeref(type_inside);
3490
3491                 if(is_type_pointer(type_left)) {
3492                         pointer_type_t *pointer = &type_left->pointer;
3493                         return_type             = pointer->points_to;
3494                         array_access->array_ref = left;
3495                         array_access->index     = inside;
3496                 } else if(is_type_pointer(type_inside)) {
3497                         pointer_type_t *pointer = &type_inside->pointer;
3498                         return_type             = pointer->points_to;
3499                         array_access->array_ref = inside;
3500                         array_access->index     = left;
3501                         array_access->flipped   = true;
3502                 } else {
3503                         parser_print_error_prefix();
3504                         fprintf(stderr, "array access on object with non-pointer types ");
3505                         print_type_quoted(type_left);
3506                         fprintf(stderr, ", ");
3507                         print_type_quoted(type_inside);
3508                         fprintf(stderr, "\n");
3509                 }
3510         } else {
3511                 array_access->array_ref = left;
3512                 array_access->index     = inside;
3513         }
3514
3515         if(token.type != ']') {
3516                 parse_error_expected("Problem while parsing array access", ']', 0);
3517                 return (expression_t*) array_access;
3518         }
3519         next_token();
3520
3521         return_type = automatic_type_conversion(return_type);
3522         array_access->expression.datatype = return_type;
3523
3524         return (expression_t*) array_access;
3525 }
3526
3527 static expression_t *parse_sizeof(unsigned precedence)
3528 {
3529         eat(T_sizeof);
3530
3531         sizeof_expression_t *sizeof_expression
3532                 = allocate_ast_zero(sizeof(sizeof_expression[0]));
3533         sizeof_expression->expression.kind     = EXPR_SIZEOF;
3534         sizeof_expression->expression.datatype = type_size_t;
3535
3536         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
3537                 next_token();
3538                 sizeof_expression->type = parse_typename();
3539                 expect(')');
3540         } else {
3541                 expression_t *expression  = parse_sub_expression(precedence);
3542                 expression->base.datatype = revert_automatic_type_conversion(expression);
3543
3544                 sizeof_expression->type            = expression->base.datatype;
3545                 sizeof_expression->size_expression = expression;
3546         }
3547
3548         return (expression_t*) sizeof_expression;
3549 }
3550
3551 static expression_t *parse_select_expression(unsigned precedence,
3552                                              expression_t *compound)
3553 {
3554         (void) precedence;
3555         assert(token.type == '.' || token.type == T_MINUSGREATER);
3556
3557         bool is_pointer = (token.type == T_MINUSGREATER);
3558         next_token();
3559
3560         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
3561         select->select.compound = compound;
3562
3563         if(token.type != T_IDENTIFIER) {
3564                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
3565                 return select;
3566         }
3567         symbol_t *symbol      = token.v.symbol;
3568         select->select.symbol = symbol;
3569         next_token();
3570
3571         type_t *orig_type = compound->base.datatype;
3572         if(orig_type == NULL)
3573                 return create_invalid_expression();
3574
3575         type_t *type = skip_typeref(orig_type);
3576
3577         type_t *type_left = type;
3578         if(is_pointer) {
3579                 if(type->kind != TYPE_POINTER) {
3580                         parser_print_error_prefix();
3581                         fprintf(stderr, "left hand side of '->' is not a pointer, but ");
3582                         print_type_quoted(orig_type);
3583                         fputc('\n', stderr);
3584                         return create_invalid_expression();
3585                 }
3586                 pointer_type_t *pointer_type = &type->pointer;
3587                 type_left                    = pointer_type->points_to;
3588         }
3589         type_left = skip_typeref(type_left);
3590
3591         if(type_left->kind != TYPE_COMPOUND_STRUCT
3592                         && type_left->kind != TYPE_COMPOUND_UNION) {
3593                 parser_print_error_prefix();
3594                 fprintf(stderr, "request for member '%s' in something not a struct or "
3595                         "union, but ", symbol->string);
3596                 print_type_quoted(type_left);
3597                 fputc('\n', stderr);
3598                 return create_invalid_expression();
3599         }
3600
3601         compound_type_t *compound_type = &type_left->compound;
3602         declaration_t   *declaration   = compound_type->declaration;
3603
3604         if(!declaration->init.is_defined) {
3605                 parser_print_error_prefix();
3606                 fprintf(stderr, "request for member '%s' of incomplete type ",
3607                         symbol->string);
3608                 print_type_quoted(type_left);
3609                 fputc('\n', stderr);
3610                 return create_invalid_expression();
3611         }
3612
3613         declaration_t *iter = declaration->context.declarations;
3614         for( ; iter != NULL; iter = iter->next) {
3615                 if(iter->symbol == symbol) {
3616                         break;
3617                 }
3618         }
3619         if(iter == NULL) {
3620                 parser_print_error_prefix();
3621                 print_type_quoted(type_left);
3622                 fprintf(stderr, " has no member named '%s'\n", symbol->string);
3623                 return create_invalid_expression();
3624         }
3625
3626         /* we always do the auto-type conversions; the & and sizeof parser contains
3627          * code to revert this! */
3628         type_t *expression_type = automatic_type_conversion(iter->type);
3629
3630         select->select.compound_entry = iter;
3631         select->base.datatype         = expression_type;
3632         return select;
3633 }
3634
3635 static expression_t *parse_call_expression(unsigned precedence,
3636                                            expression_t *expression)
3637 {
3638         (void) precedence;
3639         expression_t *result = allocate_expression_zero(EXPR_CALL);
3640
3641         call_expression_t *call  = &result->call;
3642         call->function           = expression;
3643
3644         function_type_t *function_type = NULL;
3645         type_t          *orig_type     = expression->base.datatype;
3646         if(orig_type != NULL) {
3647                 type_t *type  = skip_typeref(orig_type);
3648
3649                 if(is_type_pointer(type)) {
3650                         pointer_type_t *pointer_type = &type->pointer;
3651
3652                         type = skip_typeref(pointer_type->points_to);
3653
3654                         if (is_type_function(type)) {
3655                                 function_type             = &type->function;
3656                                 call->expression.datatype = function_type->return_type;
3657                         }
3658                 }
3659                 if(function_type == NULL) {
3660                         parser_print_error_prefix();
3661                         fputs("called object '", stderr);
3662                         print_expression(expression);
3663                         fputs("' (type ", stderr);
3664                         print_type_quoted(orig_type);
3665                         fputs(") is not a pointer to a function\n", stderr);
3666
3667                         function_type             = NULL;
3668                         call->expression.datatype = NULL;
3669                 }
3670         }
3671
3672         /* parse arguments */
3673         eat('(');
3674
3675         if(token.type != ')') {
3676                 call_argument_t *last_argument = NULL;
3677
3678                 while(true) {
3679                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
3680
3681                         argument->expression = parse_assignment_expression();
3682                         if(last_argument == NULL) {
3683                                 call->arguments = argument;
3684                         } else {
3685                                 last_argument->next = argument;
3686                         }
3687                         last_argument = argument;
3688
3689                         if(token.type != ',')
3690                                 break;
3691                         next_token();
3692                 }
3693         }
3694         expect(')');
3695
3696         if(function_type != NULL) {
3697                 function_parameter_t *parameter = function_type->parameters;
3698                 call_argument_t      *argument  = call->arguments;
3699                 for( ; parameter != NULL && argument != NULL;
3700                                 parameter = parameter->next, argument = argument->next) {
3701                         type_t *expected_type = parameter->type;
3702                         /* TODO report context in error messages */
3703                         argument->expression = create_implicit_cast(argument->expression,
3704                                                                     expected_type);
3705                 }
3706                 /* too few parameters */
3707                 if(parameter != NULL) {
3708                         parser_print_error_prefix();
3709                         fprintf(stderr, "too few arguments to function '");
3710                         print_expression(expression);
3711                         fprintf(stderr, "'\n");
3712                 } else if(argument != NULL) {
3713                         /* too many parameters */
3714                         if(!function_type->variadic
3715                                         && !function_type->unspecified_parameters) {
3716                                 parser_print_error_prefix();
3717                                 fprintf(stderr, "too many arguments to function '");
3718                                 print_expression(expression);
3719                                 fprintf(stderr, "'\n");
3720                         } else {
3721                                 /* do default promotion */
3722                                 for( ; argument != NULL; argument = argument->next) {
3723                                         type_t *type = argument->expression->base.datatype;
3724
3725                                         if(type == NULL)
3726                                                 continue;
3727
3728                                         type = skip_typeref(type);
3729                                         if(is_type_integer(type)) {
3730                                                 type = promote_integer(type);
3731                                         } else if(type == type_float) {
3732                                                 type = type_double;
3733                                         }
3734
3735                                         argument->expression
3736                                                 = create_implicit_cast(argument->expression, type);
3737                                 }
3738
3739                                 check_format(&result->call);
3740                         }
3741                 } else {
3742                         check_format(&result->call);
3743                 }
3744         }
3745
3746         return result;
3747 }
3748
3749 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
3750
3751 static bool same_compound_type(const type_t *type1, const type_t *type2)
3752 {
3753         if(!is_type_compound(type1))
3754                 return false;
3755         if(type1->kind != type2->kind)
3756                 return false;
3757
3758         const compound_type_t *compound1 = &type1->compound;
3759         const compound_type_t *compound2 = &type2->compound;
3760
3761         return compound1->declaration == compound2->declaration;
3762 }
3763
3764 static expression_t *parse_conditional_expression(unsigned precedence,
3765                                                   expression_t *expression)
3766 {
3767         eat('?');
3768
3769         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
3770
3771         conditional_expression_t *conditional = &result->conditional;
3772         conditional->condition = expression;
3773
3774         /* 6.5.15.2 */
3775         type_t *condition_type_orig = expression->base.datatype;
3776         if(condition_type_orig != NULL) {
3777                 type_t *condition_type = skip_typeref(condition_type_orig);
3778                 if(condition_type != NULL && !is_type_scalar(condition_type)) {
3779                         type_error("expected a scalar type in conditional condition",
3780                                    expression->base.source_position, condition_type_orig);
3781                 }
3782         }
3783
3784         expression_t *true_expression = parse_expression();
3785         expect(':');
3786         expression_t *false_expression = parse_sub_expression(precedence);
3787
3788         conditional->true_expression  = true_expression;
3789         conditional->false_expression = false_expression;
3790
3791         type_t *orig_true_type  = true_expression->base.datatype;
3792         type_t *orig_false_type = false_expression->base.datatype;
3793         if(orig_true_type == NULL || orig_false_type == NULL)
3794                 return result;
3795
3796         type_t *true_type  = skip_typeref(orig_true_type);
3797         type_t *false_type = skip_typeref(orig_false_type);
3798
3799         /* 6.5.15.3 */
3800         type_t *result_type = NULL;
3801         if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
3802                 result_type = semantic_arithmetic(true_type, false_type);
3803
3804                 true_expression  = create_implicit_cast(true_expression, result_type);
3805                 false_expression = create_implicit_cast(false_expression, result_type);
3806
3807                 conditional->true_expression     = true_expression;
3808                 conditional->false_expression    = false_expression;
3809                 conditional->expression.datatype = result_type;
3810         } else if (same_compound_type(true_type, false_type)
3811                         || (is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
3812                                 is_type_atomic(false_type, ATOMIC_TYPE_VOID))) {
3813                 /* just take 1 of the 2 types */
3814                 result_type = true_type;
3815         } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
3816                         && pointers_compatible(true_type, false_type)) {
3817                 /* ok */
3818                 result_type = true_type;
3819         } else {
3820                 /* TODO */
3821                 type_error_incompatible("while parsing conditional",
3822                                         expression->base.source_position, true_type,
3823                                         false_type);
3824         }
3825
3826         conditional->expression.datatype = result_type;
3827         return result;
3828 }
3829
3830 static expression_t *parse_extension(unsigned precedence)
3831 {
3832         eat(T___extension__);
3833
3834         /* TODO enable extensions */
3835
3836         return parse_sub_expression(precedence);
3837 }
3838
3839 static expression_t *parse_builtin_classify_type(const unsigned precedence)
3840 {
3841         eat(T___builtin_classify_type);
3842
3843         expression_t *result  = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
3844         result->base.datatype = type_int;
3845
3846         expect('(');
3847         expression_t *expression = parse_sub_expression(precedence);
3848         expect(')');
3849         result->classify_type.type_expression = expression;
3850
3851         return result;
3852 }
3853
3854 static void semantic_incdec(unary_expression_t *expression)
3855 {
3856         type_t *orig_type = expression->value->base.datatype;
3857         if(orig_type == NULL)
3858                 return;
3859
3860         type_t *type = skip_typeref(orig_type);
3861         if(!is_type_arithmetic(type) && type->kind != TYPE_POINTER) {
3862                 /* TODO: improve error message */
3863                 parser_print_error_prefix();
3864                 fprintf(stderr, "operation needs an arithmetic or pointer type\n");
3865                 return;
3866         }
3867
3868         expression->expression.datatype = orig_type;
3869 }
3870
3871 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
3872 {
3873         type_t *orig_type = expression->value->base.datatype;
3874         if(orig_type == NULL)
3875                 return;
3876
3877         type_t *type = skip_typeref(orig_type);
3878         if(!is_type_arithmetic(type)) {
3879                 /* TODO: improve error message */
3880                 parser_print_error_prefix();
3881                 fprintf(stderr, "operation needs an arithmetic type\n");
3882                 return;
3883         }
3884
3885         expression->expression.datatype = orig_type;
3886 }
3887
3888 static void semantic_unexpr_scalar(unary_expression_t *expression)
3889 {
3890         type_t *orig_type = expression->value->base.datatype;
3891         if(orig_type == NULL)
3892                 return;
3893
3894         type_t *type = skip_typeref(orig_type);
3895         if (!is_type_scalar(type)) {
3896                 parse_error("operand of ! must be of scalar type\n");
3897                 return;
3898         }
3899
3900         expression->expression.datatype = orig_type;
3901 }
3902
3903 static void semantic_unexpr_integer(unary_expression_t *expression)
3904 {
3905         type_t *orig_type = expression->value->base.datatype;
3906         if(orig_type == NULL)
3907                 return;
3908
3909         type_t *type = skip_typeref(orig_type);
3910         if (!is_type_integer(type)) {
3911                 parse_error("operand of ~ must be of integer type\n");
3912                 return;
3913         }
3914
3915         expression->expression.datatype = orig_type;
3916 }
3917
3918 static void semantic_dereference(unary_expression_t *expression)
3919 {
3920         type_t *orig_type = expression->value->base.datatype;
3921         if(orig_type == NULL)
3922                 return;
3923
3924         type_t *type = skip_typeref(orig_type);
3925         if(!is_type_pointer(type)) {
3926                 parser_print_error_prefix();
3927                 fputs("Unary '*' needs pointer or arrray type, but type ", stderr);
3928                 print_type_quoted(orig_type);
3929                 fputs(" given.\n", stderr);
3930                 return;
3931         }
3932
3933         pointer_type_t *pointer_type = &type->pointer;
3934         type_t         *result_type  = pointer_type->points_to;
3935
3936         result_type = automatic_type_conversion(result_type);
3937         expression->expression.datatype = result_type;
3938 }
3939
3940 static void semantic_take_addr(unary_expression_t *expression)
3941 {
3942         expression_t *value  = expression->value;
3943         value->base.datatype = revert_automatic_type_conversion(value);
3944
3945         type_t *orig_type = value->base.datatype;
3946         if(orig_type == NULL)
3947                 return;
3948
3949         if(value->kind == EXPR_REFERENCE) {
3950                 reference_expression_t *reference   = (reference_expression_t*) value;
3951                 declaration_t          *declaration = reference->declaration;
3952                 if(declaration != NULL) {
3953                         declaration->address_taken = 1;
3954                 }
3955         }
3956
3957         expression->expression.datatype = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3958 }
3959
3960 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
3961 static expression_t *parse_##unexpression_type(unsigned precedence)            \
3962 {                                                                              \
3963         eat(token_type);                                                           \
3964                                                                                \
3965         expression_t *unary_expression                                             \
3966                 = allocate_expression_zero(unexpression_type);                         \
3967         unary_expression->unary.value = parse_sub_expression(precedence);          \
3968                                                                                    \
3969         sfunc(&unary_expression->unary);                                           \
3970                                                                                \
3971         return unary_expression;                                                   \
3972 }
3973
3974 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
3975                                semantic_unexpr_arithmetic)
3976 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
3977                                semantic_unexpr_arithmetic)
3978 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
3979                                semantic_unexpr_scalar)
3980 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
3981                                semantic_dereference)
3982 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
3983                                semantic_take_addr)
3984 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
3985                                semantic_unexpr_integer)
3986 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
3987                                semantic_incdec)
3988 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
3989                                semantic_incdec)
3990
3991 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
3992                                                sfunc)                         \
3993 static expression_t *parse_##unexpression_type(unsigned precedence,           \
3994                                                expression_t *left)            \
3995 {                                                                             \
3996         (void) precedence;                                                        \
3997         eat(token_type);                                                          \
3998                                                                               \
3999         expression_t *unary_expression                                            \
4000                 = allocate_expression_zero(unexpression_type);                        \
4001         unary_expression->unary.value = left;                                     \
4002                                                                                   \
4003         sfunc(&unary_expression->unary);                                          \
4004                                                                               \
4005         return unary_expression;                                                  \
4006 }
4007
4008 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
4009                                        EXPR_UNARY_POSTFIX_INCREMENT,
4010                                        semantic_incdec)
4011 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
4012                                        EXPR_UNARY_POSTFIX_DECREMENT,
4013                                        semantic_incdec)
4014
4015 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
4016 {
4017         /* TODO: handle complex + imaginary types */
4018
4019         /* § 6.3.1.8 Usual arithmetic conversions */
4020         if(type_left == type_long_double || type_right == type_long_double) {
4021                 return type_long_double;
4022         } else if(type_left == type_double || type_right == type_double) {
4023                 return type_double;
4024         } else if(type_left == type_float || type_right == type_float) {
4025                 return type_float;
4026         }
4027
4028         type_right = promote_integer(type_right);
4029         type_left  = promote_integer(type_left);
4030
4031         if(type_left == type_right)
4032                 return type_left;
4033
4034         bool signed_left  = is_type_signed(type_left);
4035         bool signed_right = is_type_signed(type_right);
4036         int  rank_left    = get_rank(type_left);
4037         int  rank_right   = get_rank(type_right);
4038         if(rank_left < rank_right) {
4039                 if(signed_left == signed_right || !signed_right) {
4040                         return type_right;
4041                 } else {
4042                         return type_left;
4043                 }
4044         } else {
4045                 if(signed_left == signed_right || !signed_left) {
4046                         return type_left;
4047                 } else {
4048                         return type_right;
4049                 }
4050         }
4051 }
4052
4053 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
4054 {
4055         expression_t *left       = expression->left;
4056         expression_t *right      = expression->right;
4057         type_t       *orig_type_left  = left->base.datatype;
4058         type_t       *orig_type_right = right->base.datatype;
4059
4060         if(orig_type_left == NULL || orig_type_right == NULL)
4061                 return;
4062
4063         type_t *type_left  = skip_typeref(orig_type_left);
4064         type_t *type_right = skip_typeref(orig_type_right);
4065
4066         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4067                 /* TODO: improve error message */
4068                 parser_print_error_prefix();
4069                 fprintf(stderr, "operation needs arithmetic types\n");
4070                 return;
4071         }
4072
4073         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4074         expression->left  = create_implicit_cast(left, arithmetic_type);
4075         expression->right = create_implicit_cast(right, arithmetic_type);
4076         expression->expression.datatype = arithmetic_type;
4077 }
4078
4079 static void semantic_shift_op(binary_expression_t *expression)
4080 {
4081         expression_t *left       = expression->left;
4082         expression_t *right      = expression->right;
4083         type_t       *orig_type_left  = left->base.datatype;
4084         type_t       *orig_type_right = right->base.datatype;
4085
4086         if(orig_type_left == NULL || orig_type_right == NULL)
4087                 return;
4088
4089         type_t *type_left  = skip_typeref(orig_type_left);
4090         type_t *type_right = skip_typeref(orig_type_right);
4091
4092         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
4093                 /* TODO: improve error message */
4094                 parser_print_error_prefix();
4095                 fprintf(stderr, "operation needs integer types\n");
4096                 return;
4097         }
4098
4099         type_left  = promote_integer(type_left);
4100         type_right = promote_integer(type_right);
4101
4102         expression->left  = create_implicit_cast(left, type_left);
4103         expression->right = create_implicit_cast(right, type_right);
4104         expression->expression.datatype = type_left;
4105 }
4106
4107 static void semantic_add(binary_expression_t *expression)
4108 {
4109         expression_t *left            = expression->left;
4110         expression_t *right           = expression->right;
4111         type_t       *orig_type_left  = left->base.datatype;
4112         type_t       *orig_type_right = right->base.datatype;
4113
4114         if(orig_type_left == NULL || orig_type_right == NULL)
4115                 return;
4116
4117         type_t *type_left  = skip_typeref(orig_type_left);
4118         type_t *type_right = skip_typeref(orig_type_right);
4119
4120         /* § 5.6.5 */
4121         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4122                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4123                 expression->left  = create_implicit_cast(left, arithmetic_type);
4124                 expression->right = create_implicit_cast(right, arithmetic_type);
4125                 expression->expression.datatype = arithmetic_type;
4126                 return;
4127         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4128                 expression->expression.datatype = type_left;
4129         } else if(is_type_pointer(type_right) && is_type_integer(type_left)) {
4130                 expression->expression.datatype = type_right;
4131         } else {
4132                 parser_print_error_prefix();
4133                 fprintf(stderr, "invalid operands to binary + (");
4134                 print_type_quoted(orig_type_left);
4135                 fprintf(stderr, ", ");
4136                 print_type_quoted(orig_type_right);
4137                 fprintf(stderr, ")\n");
4138         }
4139 }
4140
4141 static void semantic_sub(binary_expression_t *expression)
4142 {
4143         expression_t *left            = expression->left;
4144         expression_t *right           = expression->right;
4145         type_t       *orig_type_left  = left->base.datatype;
4146         type_t       *orig_type_right = right->base.datatype;
4147
4148         if(orig_type_left == NULL || orig_type_right == NULL)
4149                 return;
4150
4151         type_t       *type_left       = skip_typeref(orig_type_left);
4152         type_t       *type_right      = skip_typeref(orig_type_right);
4153
4154         /* § 5.6.5 */
4155         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4156                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4157                 expression->left  = create_implicit_cast(left, arithmetic_type);
4158                 expression->right = create_implicit_cast(right, arithmetic_type);
4159                 expression->expression.datatype = arithmetic_type;
4160                 return;
4161         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4162                 expression->expression.datatype = type_left;
4163         } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
4164                 if(!pointers_compatible(type_left, type_right)) {
4165                         parser_print_error_prefix();
4166                         fprintf(stderr, "pointers to incompatible objects to binary - (");
4167                         print_type_quoted(orig_type_left);
4168                         fprintf(stderr, ", ");
4169                         print_type_quoted(orig_type_right);
4170                         fprintf(stderr, ")\n");
4171                 } else {
4172                         expression->expression.datatype = type_ptrdiff_t;
4173                 }
4174         } else {
4175                 parser_print_error_prefix();
4176                 fprintf(stderr, "invalid operands to binary - (");
4177                 print_type_quoted(orig_type_left);
4178                 fprintf(stderr, ", ");
4179                 print_type_quoted(orig_type_right);
4180                 fprintf(stderr, ")\n");
4181         }
4182 }
4183
4184 static void semantic_comparison(binary_expression_t *expression)
4185 {
4186         expression_t *left            = expression->left;
4187         expression_t *right           = expression->right;
4188         type_t       *orig_type_left  = left->base.datatype;
4189         type_t       *orig_type_right = right->base.datatype;
4190
4191         if(orig_type_left == NULL || orig_type_right == NULL)
4192                 return;
4193
4194         type_t *type_left  = skip_typeref(orig_type_left);
4195         type_t *type_right = skip_typeref(orig_type_right);
4196
4197         /* TODO non-arithmetic types */
4198         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4199                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4200                 expression->left  = create_implicit_cast(left, arithmetic_type);
4201                 expression->right = create_implicit_cast(right, arithmetic_type);
4202                 expression->expression.datatype = arithmetic_type;
4203         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
4204                 /* TODO check compatibility */
4205         } else if (is_type_pointer(type_left)) {
4206                 expression->right = create_implicit_cast(right, type_left);
4207         } else if (is_type_pointer(type_right)) {
4208                 expression->left = create_implicit_cast(left, type_right);
4209         } else {
4210                 type_error_incompatible("invalid operands in comparison",
4211                                         token.source_position, type_left, type_right);
4212         }
4213         expression->expression.datatype = type_int;
4214 }
4215
4216 static void semantic_arithmetic_assign(binary_expression_t *expression)
4217 {
4218         expression_t *left            = expression->left;
4219         expression_t *right           = expression->right;
4220         type_t       *orig_type_left  = left->base.datatype;
4221         type_t       *orig_type_right = right->base.datatype;
4222
4223         if(orig_type_left == NULL || orig_type_right == NULL)
4224                 return;
4225
4226         type_t *type_left  = skip_typeref(orig_type_left);
4227         type_t *type_right = skip_typeref(orig_type_right);
4228
4229         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4230                 /* TODO: improve error message */
4231                 parser_print_error_prefix();
4232                 fprintf(stderr, "operation needs arithmetic types\n");
4233                 return;
4234         }
4235
4236         /* combined instructions are tricky. We can't create an implicit cast on
4237          * the left side, because we need the uncasted form for the store.
4238          * The ast2firm pass has to know that left_type must be right_type
4239          * for the arithmeitc operation and create a cast by itself */
4240         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4241         expression->right       = create_implicit_cast(right, arithmetic_type);
4242         expression->expression.datatype = type_left;
4243 }
4244
4245 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
4246 {
4247         expression_t *left            = expression->left;
4248         expression_t *right           = expression->right;
4249         type_t       *orig_type_left  = left->base.datatype;
4250         type_t       *orig_type_right = right->base.datatype;
4251
4252         if(orig_type_left == NULL || orig_type_right == NULL)
4253                 return;
4254
4255         type_t *type_left  = skip_typeref(orig_type_left);
4256         type_t *type_right = skip_typeref(orig_type_right);
4257
4258         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4259                 /* combined instructions are tricky. We can't create an implicit cast on
4260                  * the left side, because we need the uncasted form for the store.
4261                  * The ast2firm pass has to know that left_type must be right_type
4262                  * for the arithmeitc operation and create a cast by itself */
4263                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
4264                 expression->right = create_implicit_cast(right, arithmetic_type);
4265                 expression->expression.datatype = type_left;
4266         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
4267                 expression->expression.datatype = type_left;
4268         } else {
4269                 parser_print_error_prefix();
4270                 fputs("Incompatible types ", stderr);
4271                 print_type_quoted(orig_type_left);
4272                 fputs(" and ", stderr);
4273                 print_type_quoted(orig_type_right);
4274                 fputs(" in assignment\n", stderr);
4275                 return;
4276         }
4277 }
4278
4279 static void semantic_logical_op(binary_expression_t *expression)
4280 {
4281         expression_t *left            = expression->left;
4282         expression_t *right           = expression->right;
4283         type_t       *orig_type_left  = left->base.datatype;
4284         type_t       *orig_type_right = right->base.datatype;
4285
4286         if(orig_type_left == NULL || orig_type_right == NULL)
4287                 return;
4288
4289         type_t *type_left  = skip_typeref(orig_type_left);
4290         type_t *type_right = skip_typeref(orig_type_right);
4291
4292         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
4293                 /* TODO: improve error message */
4294                 parser_print_error_prefix();
4295                 fprintf(stderr, "operation needs scalar types\n");
4296                 return;
4297         }
4298
4299         expression->expression.datatype = type_int;
4300 }
4301
4302 static bool has_const_fields(type_t *type)
4303 {
4304         (void) type;
4305         /* TODO */
4306         return false;
4307 }
4308
4309 static void semantic_binexpr_assign(binary_expression_t *expression)
4310 {
4311         expression_t *left           = expression->left;
4312         type_t       *orig_type_left = left->base.datatype;
4313
4314         if(orig_type_left == NULL)
4315                 return;
4316
4317         type_t *type_left = revert_automatic_type_conversion(left);
4318         type_left         = skip_typeref(orig_type_left);
4319
4320         /* must be a modifiable lvalue */
4321         if (is_type_array(type_left)) {
4322                 parser_print_error_prefix();
4323                 fprintf(stderr, "Cannot assign to arrays ('");
4324                 print_expression(left);
4325                 fprintf(stderr, "')\n");
4326                 return;
4327         }
4328         if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
4329                 parser_print_error_prefix();
4330                 fprintf(stderr, "assignment to readonly location '");
4331                 print_expression(left);
4332                 fprintf(stderr, "' (type ");
4333                 print_type_quoted(orig_type_left);
4334                 fprintf(stderr, ")\n");
4335                 return;
4336         }
4337         if(is_type_incomplete(type_left)) {
4338                 parser_print_error_prefix();
4339                 fprintf(stderr, "left-hand side of assignment '");
4340                 print_expression(left);
4341                 fprintf(stderr, "' has incomplete type ");
4342                 print_type_quoted(orig_type_left);
4343                 fprintf(stderr, "\n");
4344                 return;
4345         }
4346         if(is_type_compound(type_left) && has_const_fields(type_left)) {
4347                 parser_print_error_prefix();
4348                 fprintf(stderr, "can't assign to '");
4349                 print_expression(left);
4350                 fprintf(stderr, "' because compound type ");
4351                 print_type_quoted(orig_type_left);
4352                 fprintf(stderr, " has readonly fields\n");
4353                 return;
4354         }
4355
4356         semantic_assign(orig_type_left, &expression->right, "assignment");
4357
4358         expression->expression.datatype = orig_type_left;
4359 }
4360
4361 static void semantic_comma(binary_expression_t *expression)
4362 {
4363         expression->expression.datatype = expression->right->base.datatype;
4364 }
4365
4366 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
4367 static expression_t *parse_##binexpression_type(unsigned precedence,      \
4368                                                 expression_t *left)       \
4369 {                                                                         \
4370         eat(token_type);                                                      \
4371                                                                           \
4372         expression_t *right = parse_sub_expression(precedence + lr);          \
4373                                                                           \
4374         expression_t *binexpr = allocate_expression_zero(binexpression_type); \
4375         binexpr->binary.left  = left;                                         \
4376         binexpr->binary.right = right;                                        \
4377         sfunc(&binexpr->binary);                                              \
4378                                                                           \
4379         return binexpr;                                                       \
4380 }
4381
4382 CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
4383 CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
4384 CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
4385 CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
4386 CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
4387 CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
4388 CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
4389 CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
4390 CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
4391
4392 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
4393                       semantic_comparison, 1)
4394 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
4395                       semantic_comparison, 1)
4396 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
4397                       semantic_comparison, 1)
4398 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
4399                       semantic_comparison, 1)
4400
4401 CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
4402                       semantic_binexpr_arithmetic, 1)
4403 CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
4404                       semantic_binexpr_arithmetic, 1)
4405 CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
4406                       semantic_binexpr_arithmetic, 1)
4407 CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
4408                       semantic_logical_op, 1)
4409 CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
4410                       semantic_logical_op, 1)
4411 CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
4412                       semantic_shift_op, 1)
4413 CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
4414                       semantic_shift_op, 1)
4415 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
4416                       semantic_arithmetic_addsubb_assign, 0)
4417 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
4418                       semantic_arithmetic_addsubb_assign, 0)
4419 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
4420                       semantic_arithmetic_assign, 0)
4421 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
4422                       semantic_arithmetic_assign, 0)
4423 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
4424                       semantic_arithmetic_assign, 0)
4425 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
4426                       semantic_arithmetic_assign, 0)
4427 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4428                       semantic_arithmetic_assign, 0)
4429 CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
4430                       semantic_arithmetic_assign, 0)
4431 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
4432                       semantic_arithmetic_assign, 0)
4433 CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
4434                       semantic_arithmetic_assign, 0)
4435
4436 static expression_t *parse_sub_expression(unsigned precedence)
4437 {
4438         if(token.type < 0) {
4439                 return expected_expression_error();
4440         }
4441
4442         expression_parser_function_t *parser
4443                 = &expression_parsers[token.type];
4444         source_position_t             source_position = token.source_position;
4445         expression_t                 *left;
4446
4447         if(parser->parser != NULL) {
4448                 left = parser->parser(parser->precedence);
4449         } else {
4450                 left = parse_primary_expression();
4451         }
4452         assert(left != NULL);
4453         left->base.source_position = source_position;
4454
4455         while(true) {
4456                 if(token.type < 0) {
4457                         return expected_expression_error();
4458                 }
4459
4460                 parser = &expression_parsers[token.type];
4461                 if(parser->infix_parser == NULL)
4462                         break;
4463                 if(parser->infix_precedence < precedence)
4464                         break;
4465
4466                 left = parser->infix_parser(parser->infix_precedence, left);
4467
4468                 assert(left != NULL);
4469                 assert(left->kind != EXPR_UNKNOWN);
4470                 left->base.source_position = source_position;
4471         }
4472
4473         return left;
4474 }
4475
4476 static expression_t *parse_expression(void)
4477 {
4478         return parse_sub_expression(1);
4479 }
4480
4481
4482
4483 static void register_expression_parser(parse_expression_function parser,
4484                                        int token_type, unsigned precedence)
4485 {
4486         expression_parser_function_t *entry = &expression_parsers[token_type];
4487
4488         if(entry->parser != NULL) {
4489                 fprintf(stderr, "for token ");
4490                 print_token_type(stderr, (token_type_t) token_type);
4491                 fprintf(stderr, "\n");
4492                 panic("trying to register multiple expression parsers for a token");
4493         }
4494         entry->parser     = parser;
4495         entry->precedence = precedence;
4496 }
4497
4498 static void register_infix_parser(parse_expression_infix_function parser,
4499                 int token_type, unsigned precedence)
4500 {
4501         expression_parser_function_t *entry = &expression_parsers[token_type];
4502
4503         if(entry->infix_parser != NULL) {
4504                 fprintf(stderr, "for token ");
4505                 print_token_type(stderr, (token_type_t) token_type);
4506                 fprintf(stderr, "\n");
4507                 panic("trying to register multiple infix expression parsers for a "
4508                       "token");
4509         }
4510         entry->infix_parser     = parser;
4511         entry->infix_precedence = precedence;
4512 }
4513
4514 static void init_expression_parsers(void)
4515 {
4516         memset(&expression_parsers, 0, sizeof(expression_parsers));
4517
4518         register_infix_parser(parse_array_expression,         '[',              30);
4519         register_infix_parser(parse_call_expression,          '(',              30);
4520         register_infix_parser(parse_select_expression,        '.',              30);
4521         register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
4522         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
4523                                                               T_PLUSPLUS,       30);
4524         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
4525                                                               T_MINUSMINUS,     30);
4526
4527         register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
4528         register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
4529         register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
4530         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
4531         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
4532         register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
4533         register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
4534         register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
4535         register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
4536         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
4537         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
4538         register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
4539         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
4540                                                     T_EXCLAMATIONMARKEQUAL, 13);
4541         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
4542         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
4543         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
4544         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
4545         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
4546         register_infix_parser(parse_conditional_expression,   '?',               7);
4547         register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
4548         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
4549         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
4550         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
4551         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
4552         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
4553         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
4554                                                                 T_LESSLESSEQUAL, 2);
4555         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4556                                                           T_GREATERGREATEREQUAL, 2);
4557         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
4558                                                                      T_ANDEQUAL, 2);
4559         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
4560                                                                     T_PIPEEQUAL, 2);
4561         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
4562                                                                    T_CARETEQUAL, 2);
4563
4564         register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
4565
4566         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
4567         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
4568         register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
4569         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
4570         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
4571         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
4572         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
4573                                                                   T_PLUSPLUS,   25);
4574         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
4575                                                                   T_MINUSMINUS, 25);
4576         register_expression_parser(parse_sizeof,                  T_sizeof,     25);
4577         register_expression_parser(parse_extension,            T___extension__, 25);
4578         register_expression_parser(parse_builtin_classify_type,
4579                                                      T___builtin_classify_type, 25);
4580 }
4581
4582 static asm_constraint_t *parse_asm_constraints(void)
4583 {
4584         asm_constraint_t *result = NULL;
4585         asm_constraint_t *last   = NULL;
4586
4587         while(token.type == T_STRING_LITERAL || token.type == '[') {
4588                 asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
4589                 memset(constraint, 0, sizeof(constraint[0]));
4590
4591                 if(token.type == '[') {
4592                         eat('[');
4593                         if(token.type != T_IDENTIFIER) {
4594                                 parse_error_expected("while parsing asm constraint",
4595                                                      T_IDENTIFIER, 0);
4596                                 return NULL;
4597                         }
4598                         constraint->symbol = token.v.symbol;
4599
4600                         expect(']');
4601                 }
4602
4603                 constraint->constraints = parse_string_literals();
4604                 expect('(');
4605                 constraint->expression = parse_expression();
4606                 expect(')');
4607
4608                 if(last != NULL) {
4609                         last->next = constraint;
4610                 } else {
4611                         result = constraint;
4612                 }
4613                 last = constraint;
4614
4615                 if(token.type != ',')
4616                         break;
4617                 eat(',');
4618         }
4619
4620         return result;
4621 }
4622
4623 static asm_clobber_t *parse_asm_clobbers(void)
4624 {
4625         asm_clobber_t *result = NULL;
4626         asm_clobber_t *last   = NULL;
4627
4628         while(token.type == T_STRING_LITERAL) {
4629                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
4630                 clobber->clobber       = parse_string_literals();
4631
4632                 if(last != NULL) {
4633                         last->next = clobber;
4634                 } else {
4635                         result = clobber;
4636                 }
4637                 last = clobber;
4638
4639                 if(token.type != ',')
4640                         break;
4641                 eat(',');
4642         }
4643
4644         return result;
4645 }
4646
4647 static statement_t *parse_asm_statement(void)
4648 {
4649         eat(T_asm);
4650
4651         statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
4652         statement->base.source_position = token.source_position;
4653
4654         asm_statement_t *asm_statement = &statement->asms;
4655
4656         if(token.type == T_volatile) {
4657                 next_token();
4658                 asm_statement->is_volatile = true;
4659         }
4660
4661         expect('(');
4662         asm_statement->asm_text = parse_string_literals();
4663
4664         if(token.type != ':')
4665                 goto end_of_asm;
4666         eat(':');
4667
4668         asm_statement->inputs = parse_asm_constraints();
4669         if(token.type != ':')
4670                 goto end_of_asm;
4671         eat(':');
4672
4673         asm_statement->outputs = parse_asm_constraints();
4674         if(token.type != ':')
4675                 goto end_of_asm;
4676         eat(':');
4677
4678         asm_statement->clobbers = parse_asm_clobbers();
4679
4680 end_of_asm:
4681         expect(')');
4682         expect(';');
4683         return statement;
4684 }
4685
4686 static statement_t *parse_case_statement(void)
4687 {
4688         eat(T_case);
4689
4690         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
4691
4692         statement->base.source_position  = token.source_position;
4693         statement->case_label.expression = parse_expression();
4694
4695         expect(':');
4696         statement->case_label.label_statement = parse_statement();
4697
4698         return statement;
4699 }
4700
4701 static statement_t *parse_default_statement(void)
4702 {
4703         eat(T_default);
4704
4705         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
4706
4707         statement->base.source_position = token.source_position;
4708
4709         expect(':');
4710         statement->label.label_statement = parse_statement();
4711
4712         return statement;
4713 }
4714
4715 static declaration_t *get_label(symbol_t *symbol)
4716 {
4717         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
4718         assert(current_function != NULL);
4719         /* if we found a label in the same function, then we already created the
4720          * declaration */
4721         if(candidate != NULL
4722                         && candidate->parent_context == &current_function->context) {
4723                 return candidate;
4724         }
4725
4726         /* otherwise we need to create a new one */
4727         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
4728         declaration->namespc       = NAMESPACE_LABEL;
4729         declaration->symbol        = symbol;
4730
4731         label_push(declaration);
4732
4733         return declaration;
4734 }
4735
4736 static statement_t *parse_label_statement(void)
4737 {
4738         assert(token.type == T_IDENTIFIER);
4739         symbol_t *symbol = token.v.symbol;
4740         next_token();
4741
4742         declaration_t *label = get_label(symbol);
4743
4744         /* if source position is already set then the label is defined twice,
4745          * otherwise it was just mentioned in a goto so far */
4746         if(label->source_position.input_name != NULL) {
4747                 parser_print_error_prefix();
4748                 fprintf(stderr, "duplicate label '%s'\n", symbol->string);
4749                 parser_print_error_prefix_pos(label->source_position);
4750                 fprintf(stderr, "previous definition of '%s' was here\n",
4751                         symbol->string);
4752         } else {
4753                 label->source_position = token.source_position;
4754         }
4755
4756         label_statement_t *label_statement = allocate_ast_zero(sizeof(label[0]));
4757
4758         label_statement->statement.kind            = STATEMENT_LABEL;
4759         label_statement->statement.source_position = token.source_position;
4760         label_statement->label                     = label;
4761
4762         expect(':');
4763
4764         if(token.type == '}') {
4765                 parse_error("label at end of compound statement");
4766                 return (statement_t*) label_statement;
4767         } else {
4768                 label_statement->label_statement = parse_statement();
4769         }
4770
4771         return (statement_t*) label_statement;
4772 }
4773
4774 static statement_t *parse_if(void)
4775 {
4776         eat(T_if);
4777
4778         if_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4779         statement->statement.kind            = STATEMENT_IF;
4780         statement->statement.source_position = token.source_position;
4781
4782         expect('(');
4783         statement->condition = parse_expression();
4784         expect(')');
4785
4786         statement->true_statement = parse_statement();
4787         if(token.type == T_else) {
4788                 next_token();
4789                 statement->false_statement = parse_statement();
4790         }
4791
4792         return (statement_t*) statement;
4793 }
4794
4795 static statement_t *parse_switch(void)
4796 {
4797         eat(T_switch);
4798
4799         switch_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4800         statement->statement.kind            = STATEMENT_SWITCH;
4801         statement->statement.source_position = token.source_position;
4802
4803         expect('(');
4804         statement->expression = parse_expression();
4805         expect(')');
4806         statement->body = parse_statement();
4807
4808         return (statement_t*) statement;
4809 }
4810
4811 static statement_t *parse_while(void)
4812 {
4813         eat(T_while);
4814
4815         while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4816         statement->statement.kind            = STATEMENT_WHILE;
4817         statement->statement.source_position = token.source_position;
4818
4819         expect('(');
4820         statement->condition = parse_expression();
4821         expect(')');
4822         statement->body = parse_statement();
4823
4824         return (statement_t*) statement;
4825 }
4826
4827 static statement_t *parse_do(void)
4828 {
4829         eat(T_do);
4830
4831         do_while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4832         statement->statement.kind            = STATEMENT_DO_WHILE;
4833         statement->statement.source_position = token.source_position;
4834
4835         statement->body = parse_statement();
4836         expect(T_while);
4837         expect('(');
4838         statement->condition = parse_expression();
4839         expect(')');
4840         expect(';');
4841
4842         return (statement_t*) statement;
4843 }
4844
4845 static statement_t *parse_for(void)
4846 {
4847         eat(T_for);
4848
4849         for_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4850         statement->statement.kind            = STATEMENT_FOR;
4851         statement->statement.source_position = token.source_position;
4852
4853         expect('(');
4854
4855         int         top          = environment_top();
4856         context_t  *last_context = context;
4857         set_context(&statement->context);
4858
4859         if(token.type != ';') {
4860                 if(is_declaration_specifier(&token, false)) {
4861                         parse_declaration(record_declaration);
4862                 } else {
4863                         statement->initialisation = parse_expression();
4864                         expect(';');
4865                 }
4866         } else {
4867                 expect(';');
4868         }
4869
4870         if(token.type != ';') {
4871                 statement->condition = parse_expression();
4872         }
4873         expect(';');
4874         if(token.type != ')') {
4875                 statement->step = parse_expression();
4876         }
4877         expect(')');
4878         statement->body = parse_statement();
4879
4880         assert(context == &statement->context);
4881         set_context(last_context);
4882         environment_pop_to(top);
4883
4884         return (statement_t*) statement;
4885 }
4886
4887 static statement_t *parse_goto(void)
4888 {
4889         eat(T_goto);
4890
4891         if(token.type != T_IDENTIFIER) {
4892                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
4893                 eat_statement();
4894                 return NULL;
4895         }
4896         symbol_t *symbol = token.v.symbol;
4897         next_token();
4898
4899         declaration_t *label = get_label(symbol);
4900
4901         goto_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4902
4903         statement->statement.kind            = STATEMENT_GOTO;
4904         statement->statement.source_position = token.source_position;
4905
4906         statement->label = label;
4907
4908         expect(';');
4909
4910         return (statement_t*) statement;
4911 }
4912
4913 static statement_t *parse_continue(void)
4914 {
4915         eat(T_continue);
4916         expect(';');
4917
4918         statement_t *statement          = allocate_ast_zero(sizeof(statement[0]));
4919         statement->kind                 = STATEMENT_CONTINUE;
4920         statement->base.source_position = token.source_position;
4921
4922         return statement;
4923 }
4924
4925 static statement_t *parse_break(void)
4926 {
4927         eat(T_break);
4928         expect(';');
4929
4930         statement_t *statement          = allocate_ast_zero(sizeof(statement[0]));
4931         statement->kind                 = STATEMENT_BREAK;
4932         statement->base.source_position = token.source_position;
4933
4934         return statement;
4935 }
4936
4937 static statement_t *parse_return(void)
4938 {
4939         eat(T_return);
4940
4941         return_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
4942
4943         statement->statement.kind            = STATEMENT_RETURN;
4944         statement->statement.source_position = token.source_position;
4945
4946         assert(is_type_function(current_function->type));
4947         function_type_t *function_type = &current_function->type->function;
4948         type_t          *return_type   = function_type->return_type;
4949
4950         expression_t *return_value = NULL;
4951         if(token.type != ';') {
4952                 return_value = parse_expression();
4953         }
4954         expect(';');
4955
4956         if(return_type == NULL)
4957                 return (statement_t*) statement;
4958         if(return_value != NULL && return_value->base.datatype == NULL)
4959                 return (statement_t*) statement;
4960
4961         return_type = skip_typeref(return_type);
4962
4963         if(return_value != NULL) {
4964                 type_t *return_value_type = skip_typeref(return_value->base.datatype);
4965
4966                 if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
4967                                 && !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
4968                         parse_warning("'return' with a value, in function returning void");
4969                         return_value = NULL;
4970                 } else {
4971                         if(return_type != NULL) {
4972                                 semantic_assign(return_type, &return_value, "'return'");
4973                         }
4974                 }
4975         } else {
4976                 if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
4977                         parse_warning("'return' without value, in function returning "
4978                                       "non-void");
4979                 }
4980         }
4981         statement->return_value = return_value;
4982
4983         return (statement_t*) statement;
4984 }
4985
4986 static statement_t *parse_declaration_statement(void)
4987 {
4988         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
4989
4990         statement->base.source_position = token.source_position;
4991
4992         declaration_t *before = last_declaration;
4993         parse_declaration(record_declaration);
4994
4995         if(before == NULL) {
4996                 statement->declaration.declarations_begin = context->declarations;
4997         } else {
4998                 statement->declaration.declarations_begin = before->next;
4999         }
5000         statement->declaration.declarations_end = last_declaration;
5001
5002         return statement;
5003 }
5004
5005 static statement_t *parse_expression_statement(void)
5006 {
5007         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
5008
5009         statement->base.source_position  = token.source_position;
5010         statement->expression.expression = parse_expression();
5011
5012         expect(';');
5013
5014         return statement;
5015 }
5016
5017 static statement_t *parse_statement(void)
5018 {
5019         statement_t   *statement = NULL;
5020
5021         /* declaration or statement */
5022         switch(token.type) {
5023         case T_asm:
5024                 statement = parse_asm_statement();
5025                 break;
5026
5027         case T_case:
5028                 statement = parse_case_statement();
5029                 break;
5030
5031         case T_default:
5032                 statement = parse_default_statement();
5033                 break;
5034
5035         case '{':
5036                 statement = parse_compound_statement();
5037                 break;
5038
5039         case T_if:
5040                 statement = parse_if();
5041                 break;
5042
5043         case T_switch:
5044                 statement = parse_switch();
5045                 break;
5046
5047         case T_while:
5048                 statement = parse_while();
5049                 break;
5050
5051         case T_do:
5052                 statement = parse_do();
5053                 break;
5054
5055         case T_for:
5056                 statement = parse_for();
5057                 break;
5058
5059         case T_goto:
5060                 statement = parse_goto();
5061                 break;
5062
5063         case T_continue:
5064                 statement = parse_continue();
5065                 break;
5066
5067         case T_break:
5068                 statement = parse_break();
5069                 break;
5070
5071         case T_return:
5072                 statement = parse_return();
5073                 break;
5074
5075         case ';':
5076                 next_token();
5077                 statement = NULL;
5078                 break;
5079
5080         case T_IDENTIFIER:
5081                 if(look_ahead(1)->type == ':') {
5082                         statement = parse_label_statement();
5083                         break;
5084                 }
5085
5086                 if(is_typedef_symbol(token.v.symbol)) {
5087                         statement = parse_declaration_statement();
5088                         break;
5089                 }
5090
5091                 statement = parse_expression_statement();
5092                 break;
5093
5094         case T___extension__:
5095                 /* this can be a prefix to a declaration or an expression statement */
5096                 /* we simply eat it now and parse the rest with tail recursion */
5097                 do {
5098                         next_token();
5099                 } while(token.type == T___extension__);
5100                 statement = parse_statement();
5101                 break;
5102
5103         DECLARATION_START
5104                 statement = parse_declaration_statement();
5105                 break;
5106
5107         default:
5108                 statement = parse_expression_statement();
5109                 break;
5110         }
5111
5112         assert(statement == NULL
5113                         || statement->base.source_position.input_name != NULL);
5114
5115         return statement;
5116 }
5117
5118 static statement_t *parse_compound_statement(void)
5119 {
5120         compound_statement_t *compound_statement
5121                 = allocate_ast_zero(sizeof(compound_statement[0]));
5122         compound_statement->statement.kind            = STATEMENT_COMPOUND;
5123         compound_statement->statement.source_position = token.source_position;
5124
5125         eat('{');
5126
5127         int        top          = environment_top();
5128         context_t *last_context = context;
5129         set_context(&compound_statement->context);
5130
5131         statement_t *last_statement = NULL;
5132
5133         while(token.type != '}' && token.type != T_EOF) {
5134                 statement_t *statement = parse_statement();
5135                 if(statement == NULL)
5136                         continue;
5137
5138                 if(last_statement != NULL) {
5139                         last_statement->base.next = statement;
5140                 } else {
5141                         compound_statement->statements = statement;
5142                 }
5143
5144                 while(statement->base.next != NULL)
5145                         statement = statement->base.next;
5146
5147                 last_statement = statement;
5148         }
5149
5150         if(token.type != '}') {
5151                 parser_print_error_prefix_pos(
5152                                 compound_statement->statement.source_position);
5153                 fprintf(stderr, "end of file while looking for closing '}'\n");
5154         }
5155         next_token();
5156
5157         assert(context == &compound_statement->context);
5158         set_context(last_context);
5159         environment_pop_to(top);
5160
5161         return (statement_t*) compound_statement;
5162 }
5163
5164 static void initialize_builtins(void)
5165 {
5166         type_intmax_t    = make_global_typedef("__intmax_t__",      type_long_long);
5167         type_size_t      = make_global_typedef("__SIZE_TYPE__",     type_unsigned_long);
5168         type_ssize_t     = make_global_typedef("__SSIZE_TYPE__",    type_long);
5169         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
5170         type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
5171         type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
5172         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    type_int);
5173         type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
5174
5175         type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
5176         type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
5177         type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
5178         type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
5179 }
5180
5181 static translation_unit_t *parse_translation_unit(void)
5182 {
5183         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
5184
5185         assert(global_context == NULL);
5186         global_context = &unit->context;
5187
5188         assert(context == NULL);
5189         set_context(&unit->context);
5190
5191         initialize_builtins();
5192
5193         while(token.type != T_EOF) {
5194                 parse_external_declaration();
5195         }
5196
5197         assert(context == &unit->context);
5198         context          = NULL;
5199         last_declaration = NULL;
5200
5201         assert(global_context == &unit->context);
5202         global_context = NULL;
5203
5204         return unit;
5205 }
5206
5207 translation_unit_t *parse(void)
5208 {
5209         environment_stack = NEW_ARR_F(stack_entry_t, 0);
5210         label_stack       = NEW_ARR_F(stack_entry_t, 0);
5211         found_error       = false;
5212
5213         type_set_output(stderr);
5214         ast_set_output(stderr);
5215
5216         lookahead_bufpos = 0;
5217         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
5218                 next_token();
5219         }
5220         translation_unit_t *unit = parse_translation_unit();
5221
5222         DEL_ARR_F(environment_stack);
5223         DEL_ARR_F(label_stack);
5224
5225         if(found_error)
5226                 return NULL;
5227
5228         return unit;
5229 }
5230
5231 void init_parser(void)
5232 {
5233         init_expression_parsers();
5234         obstack_init(&temp_obst);
5235
5236         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
5237         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
5238 }
5239
5240 void exit_parser(void)
5241 {
5242         obstack_free(&temp_obst, NULL);
5243 }