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 "lang_features.h"
  17 #include "adt/bitfiddle.h"
  18 #include "adt/error.h"
  19 #include "adt/array.h"
  20
  21 //#define PRINT_TOKENS
  22 //#define ABORT_ON_ERROR
  23 #define MAX_LOOKAHEAD 2
  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 switch_statement_t *current_switch    = NULL;
  52 static statement_t        *current_loop      = NULL;
  53 static goto_statement_t   *goto_list         = NULL;
  54 static struct obstack  temp_obst;
  55
  56 /** The current source position. */
  57 #define HERE token.source_position
  58
  59 static type_t *type_valist;
  60
  61 static statement_t *parse_compound_statement(void);
  62 static statement_t *parse_statement(void);
  63
  64 static expression_t *parse_sub_expression(unsigned precedence);
  65 static expression_t *parse_expression(void);
  66 static type_t       *parse_typename(void);
  67
  68 static void parse_compound_type_entries(void);
  69 static declaration_t *parse_declarator(
  70                 const declaration_specifiers_t *specifiers, bool may_be_abstract);
  71 static declaration_t *record_declaration(declaration_t *declaration);
  72
  73 static void semantic_comparison(binary_expression_t *expression);
  74
  75 #define STORAGE_CLASSES     \
  76         case T_typedef:         \
  77         case T_extern:          \
  78         case T_static:          \
  79         case T_auto:            \
  80         case T_register:
  81
  82 #define TYPE_QUALIFIERS     \
  83         case T_const:           \
  84         case T_restrict:        \
  85         case T_volatile:        \
  86         case T_inline:          \
  87         case T_forceinline:
  88
  89 #ifdef PROVIDE_COMPLEX
  90 #define COMPLEX_SPECIFIERS  \
  91         case T__Complex:
  92 #define IMAGINARY_SPECIFIERS \
  93         case T__Imaginary:
  94 #else
  95 #define COMPLEX_SPECIFIERS
  96 #define IMAGINARY_SPECIFIERS
  97 #endif
  98
  99 #define TYPE_SPECIFIERS       \
 100         case T_void:              \
 101         case T_char:              \
 102         case T_short:             \
 103         case T_int:               \
 104         case T_long:              \
 105         case T_float:             \
 106         case T_double:            \
 107         case T_signed:            \
 108         case T_unsigned:          \
 109         case T__Bool:             \
 110         case T_struct:            \
 111         case T_union:             \
 112         case T_enum:              \
 113         case T___typeof__:        \
 114         case T___builtin_va_list: \
 115         COMPLEX_SPECIFIERS        \
 116         IMAGINARY_SPECIFIERS
 117
 118 #define DECLARATION_START   \
 119         STORAGE_CLASSES         \
 120         TYPE_QUALIFIERS         \
 121         TYPE_SPECIFIERS
 122
 123 #define TYPENAME_START      \
 124         TYPE_QUALIFIERS         \
 125         TYPE_SPECIFIERS
 126
 127 /**
 128  * Allocate an AST node with given size and
 129  * initialize all fields with zero.
 130  */
 131 static void *allocate_ast_zero(size_t size)
 132 {
 133         void *res = allocate_ast(size);
 134         memset(res, 0, size);
 135         return res;
 136 }
 137
 138 /**
 139  * Returns the size of a statement node.
 140  *
 141  * @param kind  the statement kind
 142  */
 143 static size_t get_statement_struct_size(statement_kind_t kind)
 144 {
 145         static const size_t sizes[] = {
 146                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 147                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 148                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 149                 [STATEMENT_IF]          = sizeof(if_statement_t),
 150                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 151                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 152                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 153                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 154                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 155                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 156                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 157                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 158                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 159                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 160                 [STATEMENT_ASM]         = sizeof(asm_statement_t)
 161         };
 162         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 163         assert(sizes[kind] != 0);
 164         return sizes[kind];
 165 }
 166
 167 /**
 168  * Allocate a statement node of given kind and initialize all
 169  * fields with zero.
 170  */
 171 static statement_t *allocate_statement_zero(statement_kind_t kind)
 172 {
 173         size_t       size = get_statement_struct_size(kind);
 174         statement_t *res  = allocate_ast_zero(size);
 175
 176         res->base.kind = kind;
 177         return res;
 178 }
 179
 180 /**
 181  * Returns the size of an expression node.
 182  *
 183  * @param kind  the expression kind
 184  */
 185 static size_t get_expression_struct_size(expression_kind_t kind)
 186 {
 187         static const size_t sizes[] = {
 188                 [EXPR_INVALID]             = sizeof(expression_base_t),
 189                 [EXPR_REFERENCE]           = sizeof(reference_expression_t),
 190                 [EXPR_CONST]               = sizeof(const_expression_t),
 191                 [EXPR_STRING_LITERAL]      = sizeof(string_literal_expression_t),
 192                 [EXPR_WIDE_STRING_LITERAL] = sizeof(wide_string_literal_expression_t),
 193                 [EXPR_CALL]                = sizeof(call_expression_t),
 194                 [EXPR_UNARY_FIRST]         = sizeof(unary_expression_t),
 195                 [EXPR_BINARY_FIRST]        = sizeof(binary_expression_t),
 196                 [EXPR_CONDITIONAL]         = sizeof(conditional_expression_t),
 197                 [EXPR_SELECT]              = sizeof(select_expression_t),
 198                 [EXPR_ARRAY_ACCESS]        = sizeof(array_access_expression_t),
 199                 [EXPR_SIZEOF]              = sizeof(sizeof_expression_t),
 200                 [EXPR_CLASSIFY_TYPE]       = sizeof(classify_type_expression_t),
 201                 [EXPR_FUNCTION]            = sizeof(string_literal_expression_t),
 202                 [EXPR_PRETTY_FUNCTION]     = sizeof(string_literal_expression_t),
 203                 [EXPR_BUILTIN_SYMBOL]      = sizeof(builtin_symbol_expression_t),
 204                 [EXPR_BUILTIN_CONSTANT_P]  = sizeof(builtin_constant_expression_t),
 205                 [EXPR_BUILTIN_PREFETCH]    = sizeof(builtin_prefetch_expression_t),
 206                 [EXPR_OFFSETOF]            = sizeof(offsetof_expression_t),
 207                 [EXPR_VA_START]            = sizeof(va_start_expression_t),
 208                 [EXPR_VA_ARG]              = sizeof(va_arg_expression_t),
 209                 [EXPR_STATEMENT]           = sizeof(statement_expression_t),
 210         };
 211         if(kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 212                 return sizes[EXPR_UNARY_FIRST];
 213         }
 214         if(kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 215                 return sizes[EXPR_BINARY_FIRST];
 216         }
 217         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 218         assert(sizes[kind] != 0);
 219         return sizes[kind];
 220 }
 221
 222 /**
 223  * Allocate an expression node of given kind and initialize all
 224  * fields with zero.
 225  */
 226 static expression_t *allocate_expression_zero(expression_kind_t kind)
 227 {
 228         size_t        size = get_expression_struct_size(kind);
 229         expression_t *res  = allocate_ast_zero(size);
 230
 231         res->base.kind = kind;
 232         return res;
 233 }
 234
 235 /**
 236  * Returns the size of a type node.
 237  *
 238  * @param kind  the type kind
 239  */
 240 static size_t get_type_struct_size(type_kind_t kind)
 241 {
 242         static const size_t sizes[] = {
 243                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 244                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 245                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 246                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 247                 [TYPE_ENUM]            = sizeof(enum_type_t),
 248                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 249                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 250                 [TYPE_ARRAY]           = sizeof(array_type_t),
 251                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 252                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 253                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 254         };
 255         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 256         assert(kind <= TYPE_TYPEOF);
 257         assert(sizes[kind] != 0);
 258         return sizes[kind];
 259 }
 260
 261 /**
 262  * Allocate a type node of given kind and initialize all
 263  * fields with zero.
 264  */
 265 static type_t *allocate_type_zero(type_kind_t kind)
 266 {
 267         size_t  size = get_type_struct_size(kind);
 268         type_t *res  = obstack_alloc(type_obst, size);
 269         memset(res, 0, size);
 270
 271         res->base.kind = kind;
 272         return res;
 273 }
 274
 275 /**
 276  * Returns the size of an initializer node.
 277  *
 278  * @param kind  the initializer kind
 279  */
 280 static size_t get_initializer_size(initializer_kind_t kind)
 281 {
 282         static const size_t sizes[] = {
 283                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 284                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 285                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 286                 [INITIALIZER_LIST]        = sizeof(initializer_list_t)
 287         };
 288         assert(kind < sizeof(sizes) / sizeof(*sizes));
 289         assert(sizes[kind] != 0);
 290         return sizes[kind];
 291 }
 292
 293 /**
 294  * Allocate an initializer node of given kind and initialize all
 295  * fields with zero.
 296  */
 297 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 298 {
 299         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 300         result->kind          = kind;
 301
 302         return result;
 303 }
 304
 305 /**
 306  * Free a type from the type obstack.
 307  */
 308 static void free_type(void *type)
 309 {
 310         obstack_free(type_obst, type);
 311 }
 312
 313 /**
 314  * Returns the index of the top element of the environment stack.
 315  */
 316 static size_t environment_top(void)
 317 {
 318         return ARR_LEN(environment_stack);
 319 }
 320
 321 /**
 322  * Returns the index of the top element of the label stack.
 323  */
 324 static size_t label_top(void)
 325 {
 326         return ARR_LEN(label_stack);
 327 }
 328
 329
 330 /**
 331  * Return the next token.
 332  */
 333 static inline void next_token(void)
 334 {
 335         token                              = lookahead_buffer[lookahead_bufpos];
 336         lookahead_buffer[lookahead_bufpos] = lexer_token;
 337         lexer_next_token();
 338
 339         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 340
 341 #ifdef PRINT_TOKENS
 342         print_token(stderr, &token);
 343         fprintf(stderr, "\n");
 344 #endif
 345 }
 346
 347 /**
 348  * Return the next token with a given lookahead.
 349  */
 350 static inline const token_t *look_ahead(int num)
 351 {
 352         assert(num > 0 && num <= MAX_LOOKAHEAD);
 353         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 354         return &lookahead_buffer[pos];
 355 }
 356
 357 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
 358
 359 /**
 360  * Report a parse error because an expected token was not found.
 361  */
 362 static void parse_error_expected(const char *message, ...)
 363 {
 364         if(message != NULL) {
 365                 errorf(HERE, "%s", message);
 366         }
 367         va_list ap;
 368         va_start(ap, message);
 369         errorf(HERE, "got '%K', expected %#k", &token, &ap, ", ");
 370         va_end(ap);
 371 }
 372
 373 /**
 374  * Report a type error.
 375  */
 376 static void type_error(const char *msg, const source_position_t source_position,
 377                        type_t *type)
 378 {
 379         errorf(source_position, "%s, but found type '%T'", msg, type);
 380 }
 381
 382 /**
 383  * Report an incompatible type.
 384  */
 385 static void type_error_incompatible(const char *msg,
 386                 const source_position_t source_position, type_t *type1, type_t *type2)
 387 {
 388         errorf(source_position, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 389 }
 390
 391 /**
 392  * Eat an complete block, ie. '{ ... }'.
 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 /**
 412  * Eat a statement until an ';' token.
 413  */
 414 static void eat_statement(void)
 415 {
 416         while(token.type != ';') {
 417                 if(token.type == T_EOF)
 418                         return;
 419                 if(token.type == '}')
 420                         return;
 421                 if(token.type == '{') {
 422                         eat_block();
 423                         continue;
 424                 }
 425                 next_token();
 426         }
 427         eat(';');
 428 }
 429
 430 /**
 431  * Eat a parenthesed term, ie. '( ... )'.
 432  */
 433 static void eat_paren(void)
 434 {
 435         if(token.type == '(')
 436                 next_token();
 437
 438         while(token.type != ')') {
 439                 if(token.type == T_EOF)
 440                         return;
 441                 if(token.type == ')' || token.type == ';' || token.type == '}') {
 442                         return;
 443                 }
 444                 if(token.type == '(') {
 445                         eat_paren();
 446                         continue;
 447                 }
 448                 if(token.type == '{') {
 449                         eat_block();
 450                         continue;
 451                 }
 452                 next_token();
 453         }
 454         eat(')');
 455 }
 456
 457 #define expect(expected)                           \
 458     if(UNLIKELY(token.type != (expected))) {       \
 459         parse_error_expected(NULL, (expected), 0); \
 460         eat_statement();                           \
 461         return NULL;                               \
 462     }                                              \
 463     next_token();
 464
 465 #define expect_fail(expected)                      \
 466     if(UNLIKELY(token.type != (expected))) {       \
 467         parse_error_expected(NULL, (expected), 0); \
 468         eat_statement();                           \
 469         goto fail;                                 \
 470     }                                              \
 471     next_token();
 472
 473 #define expect_block(expected)                     \
 474     if(UNLIKELY(token.type != (expected))) {       \
 475         parse_error_expected(NULL, (expected), 0); \
 476         eat_block();                               \
 477         return NULL;                               \
 478     }                                              \
 479     next_token();
 480
 481 #define expect_void(expected)                      \
 482     if(UNLIKELY(token.type != (expected))) {       \
 483         parse_error_expected(NULL, (expected), 0); \
 484         eat_statement();                           \
 485         return;                                    \
 486     }                                              \
 487     next_token();
 488
 489 static void set_context(context_t *new_context)
 490 {
 491         context = new_context;
 492
 493         last_declaration = new_context->declarations;
 494         if(last_declaration != NULL) {
 495                 while(last_declaration->next != NULL) {
 496                         last_declaration = last_declaration->next;
 497                 }
 498         }
 499 }
 500
 501 /**
 502  * Search a symbol in a given namespace and returns its declaration or
 503  * NULL if this symbol was not found.
 504  */
 505 static declaration_t *get_declaration(const symbol_t *const symbol, const namespace_t namespc)
 506 {
 507         declaration_t *declaration = symbol->declaration;
 508         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 509                 if(declaration->namespc == namespc)
 510                         return declaration;
 511         }
 512
 513         return NULL;
 514 }
 515
 516 /**
 517  * pushs an environment_entry on the environment stack and links the
 518  * corresponding symbol to the new entry
 519  */
 520 static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
 521 {
 522         symbol_t    *symbol    = declaration->symbol;
 523         namespace_t  namespc = (namespace_t)declaration->namespc;
 524
 525         /* remember old declaration */
 526         stack_entry_t entry;
 527         entry.symbol          = symbol;
 528         entry.old_declaration = symbol->declaration;
 529         entry.namespc         = (unsigned short) namespc;
 530         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 531
 532         /* replace/add declaration into declaration list of the symbol */
 533         if(symbol->declaration == NULL) {
 534                 symbol->declaration = declaration;
 535         } else {
 536                 declaration_t *iter_last = NULL;
 537                 declaration_t *iter      = symbol->declaration;
 538                 for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 539                         /* replace an entry? */
 540                         if(iter->namespc == namespc) {
 541                                 if(iter_last == NULL) {
 542                                         symbol->declaration = declaration;
 543                                 } else {
 544                                         iter_last->symbol_next = declaration;
 545                                 }
 546                                 declaration->symbol_next = iter->symbol_next;
 547                                 break;
 548                         }
 549                 }
 550                 if(iter == NULL) {
 551                         assert(iter_last->symbol_next == NULL);
 552                         iter_last->symbol_next = declaration;
 553                 }
 554         }
 555 }
 556
 557 static void environment_push(declaration_t *declaration)
 558 {
 559         assert(declaration->source_position.input_name != NULL);
 560         assert(declaration->parent_context != NULL);
 561         stack_push(&environment_stack, declaration);
 562 }
 563
 564 static void label_push(declaration_t *declaration)
 565 {
 566         declaration->parent_context = &current_function->context;
 567         stack_push(&label_stack, declaration);
 568 }
 569
 570 /**
 571  * pops symbols from the environment stack until @p new_top is the top element
 572  */
 573 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 574 {
 575         stack_entry_t *stack = *stack_ptr;
 576         size_t         top   = ARR_LEN(stack);
 577         size_t         i;
 578
 579         assert(new_top <= top);
 580         if(new_top == top)
 581                 return;
 582
 583         for(i = top; i > new_top; --i) {
 584                 stack_entry_t *entry = &stack[i - 1];
 585
 586                 declaration_t *old_declaration = entry->old_declaration;
 587                 symbol_t      *symbol          = entry->symbol;
 588                 namespace_t    namespc         = (namespace_t)entry->namespc;
 589
 590                 /* replace/remove declaration */
 591                 declaration_t *declaration = symbol->declaration;
 592                 assert(declaration != NULL);
 593                 if(declaration->namespc == namespc) {
 594                         if(old_declaration == NULL) {
 595                                 symbol->declaration = declaration->symbol_next;
 596                         } else {
 597                                 symbol->declaration = old_declaration;
 598                         }
 599                 } else {
 600                         declaration_t *iter_last = declaration;
 601                         declaration_t *iter      = declaration->symbol_next;
 602                         for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 603                                 /* replace an entry? */
 604                                 if(iter->namespc == namespc) {
 605                                         assert(iter_last != NULL);
 606                                         iter_last->symbol_next = old_declaration;
 607                                         old_declaration->symbol_next = iter->symbol_next;
 608                                         break;
 609                                 }
 610                         }
 611                         assert(iter != NULL);
 612                 }
 613         }
 614
 615         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 616 }
 617
 618 static void environment_pop_to(size_t new_top)
 619 {
 620         stack_pop_to(&environment_stack, new_top);
 621 }
 622
 623 static void label_pop_to(size_t new_top)
 624 {
 625         stack_pop_to(&label_stack, new_top);
 626 }
 627
 628
 629 static int get_rank(const type_t *type)
 630 {
 631         assert(!is_typeref(type));
 632         /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
 633          * and esp. footnote 108). However we can't fold constants (yet), so we
 634          * can't decide whether unsigned int is possible, while int always works.
 635          * (unsigned int would be preferable when possible... for stuff like
 636          *  struct { enum { ... } bla : 4; } ) */
 637         if(type->kind == TYPE_ENUM)
 638                 return ATOMIC_TYPE_INT;
 639
 640         assert(type->kind == TYPE_ATOMIC);
 641         const atomic_type_t *atomic_type = &type->atomic;
 642         atomic_type_kind_t   atype       = atomic_type->akind;
 643         return atype;
 644 }
 645
 646 static type_t *promote_integer(type_t *type)
 647 {
 648         if(type->kind == TYPE_BITFIELD)
 649                 return promote_integer(type->bitfield.base);
 650
 651         if(get_rank(type) < ATOMIC_TYPE_INT)
 652                 type = type_int;
 653
 654         return type;
 655 }
 656
 657 /**
 658  * Create a cast expression.
 659  *
 660  * @param expression  the expression to cast
 661  * @param dest_type   the destination type
 662  */
 663 static expression_t *create_cast_expression(expression_t *expression,
 664                                             type_t *dest_type)
 665 {
 666         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 667
 668         cast->unary.value   = expression;
 669         cast->base.datatype = dest_type;
 670
 671         return cast;
 672 }
 673
 674 /**
 675  * Check if a given expression represents the 0 pointer constant.
 676  */
 677 static bool is_null_pointer_constant(const expression_t *expression)
 678 {
 679         /* skip void* cast */
 680         if(expression->kind == EXPR_UNARY_CAST
 681                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 682                 expression = expression->unary.value;
 683         }
 684
 685         /* TODO: not correct yet, should be any constant integer expression
 686          * which evaluates to 0 */
 687         if (expression->kind != EXPR_CONST)
 688                 return false;
 689
 690         type_t *const type = skip_typeref(expression->base.datatype);
 691         if (!is_type_integer(type))
 692                 return false;
 693
 694         return expression->conste.v.int_value == 0;
 695 }
 696
 697 /**
 698  * Create an implicit cast expression.
 699  *
 700  * @param expression  the expression to cast
 701  * @param dest_type   the destination type
 702  */
 703 static expression_t *create_implicit_cast(expression_t *expression,
 704                                           type_t *dest_type)
 705 {
 706         type_t *source_type = expression->base.datatype;
 707
 708         if(source_type == NULL)
 709                 return expression;
 710
 711         source_type = skip_typeref(source_type);
 712         dest_type   = skip_typeref(dest_type);
 713
 714         if(source_type == dest_type)
 715                 return expression;
 716
 717         switch (dest_type->kind) {
 718                 case TYPE_ENUM:
 719                         /* TODO warning for implicitly converting to enum */
 720                 case TYPE_BITFIELD:
 721                 case TYPE_ATOMIC:
 722                         if (source_type->kind != TYPE_ATOMIC &&
 723                                         source_type->kind != TYPE_ENUM &&
 724                                         source_type->kind != TYPE_BITFIELD) {
 725                                 panic("casting of non-atomic types not implemented yet");
 726                         }
 727
 728                         if(is_type_floating(dest_type) && !is_type_scalar(source_type)) {
 729                                 type_error_incompatible("can't cast types",
 730                                                 expression->base.source_position, source_type,
 731                                                 dest_type);
 732                                 return expression;
 733                         }
 734
 735                         return create_cast_expression(expression, dest_type);
 736
 737                 case TYPE_POINTER:
 738                         switch (source_type->kind) {
 739                                 case TYPE_ATOMIC:
 740                                         if (is_null_pointer_constant(expression)) {
 741                                                 return create_cast_expression(expression, dest_type);
 742                                         }
 743                                         break;
 744
 745                                 case TYPE_POINTER:
 746                                         if (pointers_compatible(source_type, dest_type)) {
 747                                                 return create_cast_expression(expression, dest_type);
 748                                         }
 749                                         break;
 750
 751                                 case TYPE_ARRAY: {
 752                                         array_type_t   *array_type   = &source_type->array;
 753                                         pointer_type_t *pointer_type = &dest_type->pointer;
 754                                         if (types_compatible(array_type->element_type,
 755                                                                                  pointer_type->points_to)) {
 756                                                 return create_cast_expression(expression, dest_type);
 757                                         }
 758                                         break;
 759                                 }
 760
 761                                 default:
 762                                         panic("casting of non-atomic types not implemented yet");
 763                         }
 764
 765                         type_error_incompatible("can't implicitly cast types",
 766                                         expression->base.source_position, source_type, dest_type);
 767                         return expression;
 768
 769                 default:
 770                         panic("casting of non-atomic types not implemented yet");
 771         }
 772 }
 773
 774 /** Implements the rules from § 6.5.16.1 */
 775 static void semantic_assign(type_t *orig_type_left, expression_t **right,
 776                             const char *context)
 777 {
 778         type_t *orig_type_right = (*right)->base.datatype;
 779
 780         if(orig_type_right == NULL)
 781                 return;
 782
 783         type_t *const type_left  = skip_typeref(orig_type_left);
 784         type_t *const type_right = skip_typeref(orig_type_right);
 785
 786         if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 787             (is_type_pointer(type_left) && is_null_pointer_constant(*right)) ||
 788             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 789                 && is_type_pointer(type_right))) {
 790                 *right = create_implicit_cast(*right, type_left);
 791                 return;
 792         }
 793
 794         if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
 795                 pointer_type_t *pointer_type_left  = &type_left->pointer;
 796                 pointer_type_t *pointer_type_right = &type_right->pointer;
 797                 type_t         *points_to_left     = pointer_type_left->points_to;
 798                 type_t         *points_to_right    = pointer_type_right->points_to;
 799
 800                 points_to_left  = skip_typeref(points_to_left);
 801                 points_to_right = skip_typeref(points_to_right);
 802
 803                 /* the left type has all qualifiers from the right type */
 804                 unsigned missing_qualifiers
 805                         = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 806                 if(missing_qualifiers != 0) {
 807                         errorf(HERE, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointed-to type", type_left, context, type_right, missing_qualifiers);
 808                         return;
 809                 }
 810
 811                 points_to_left  = get_unqualified_type(points_to_left);
 812                 points_to_right = get_unqualified_type(points_to_right);
 813
 814                 if(!is_type_atomic(points_to_left, ATOMIC_TYPE_VOID)
 815                                 && !is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)
 816                                 && !types_compatible(points_to_left, points_to_right)) {
 817                         goto incompatible_assign_types;
 818                 }
 819
 820                 *right = create_implicit_cast(*right, type_left);
 821                 return;
 822         }
 823
 824         if (is_type_compound(type_left)
 825                         && types_compatible(type_left, type_right)) {
 826                 *right = create_implicit_cast(*right, type_left);
 827                 return;
 828         }
 829
 830 incompatible_assign_types:
 831         /* TODO: improve error message */
 832         errorf(HERE, "incompatible types in %s", context);
 833         errorf(HERE, "'%T' <- '%T'", orig_type_left, orig_type_right);
 834 }
 835
 836 static expression_t *parse_constant_expression(void)
 837 {
 838         /* start parsing at precedence 7 (conditional expression) */
 839         expression_t *result = parse_sub_expression(7);
 840
 841         if(!is_constant_expression(result)) {
 842                 errorf(result->base.source_position, "expression '%E' is not constant\n", result);
 843         }
 844
 845         return result;
 846 }
 847
 848 static expression_t *parse_assignment_expression(void)
 849 {
 850         /* start parsing at precedence 2 (assignment expression) */
 851         return parse_sub_expression(2);
 852 }
 853
 854 static type_t *make_global_typedef(const char *name, type_t *type)
 855 {
 856         symbol_t *const symbol       = symbol_table_insert(name);
 857
 858         declaration_t *declaration   = allocate_ast_zero(sizeof(declaration[0]));
 859         declaration->namespc         = NAMESPACE_NORMAL;
 860         declaration->storage_class   = STORAGE_CLASS_TYPEDEF;
 861         declaration->type            = type;
 862         declaration->symbol          = symbol;
 863         declaration->source_position = builtin_source_position;
 864
 865         record_declaration(declaration);
 866
 867         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF);
 868         typedef_type->typedeft.declaration = declaration;
 869
 870         return typedef_type;
 871 }
 872
 873 static const char *parse_string_literals(void)
 874 {
 875         assert(token.type == T_STRING_LITERAL);
 876         const char *result = token.v.string;
 877
 878         next_token();
 879
 880         while(token.type == T_STRING_LITERAL) {
 881                 result = concat_strings(result, token.v.string);
 882                 next_token();
 883         }
 884
 885         return result;
 886 }
 887
 888 static void parse_attributes(void)
 889 {
 890         while(true) {
 891                 switch(token.type) {
 892                 case T___attribute__: {
 893                         next_token();
 894
 895                         expect_void('(');
 896                         int depth = 1;
 897                         while(depth > 0) {
 898                                 switch(token.type) {
 899                                 case T_EOF:
 900                                         errorf(HERE, "EOF while parsing attribute");
 901                                         break;
 902                                 case '(':
 903                                         next_token();
 904                                         depth++;
 905                                         break;
 906                                 case ')':
 907                                         next_token();
 908                                         depth--;
 909                                         break;
 910                                 default:
 911                                         next_token();
 912                                 }
 913                         }
 914                         break;
 915                 }
 916                 case T_asm:
 917                         next_token();
 918                         expect_void('(');
 919                         if(token.type != T_STRING_LITERAL) {
 920                                 parse_error_expected("while parsing assembler attribute",
 921                                                      T_STRING_LITERAL);
 922                                 eat_paren();
 923                                 break;
 924                         } else {
 925                                 parse_string_literals();
 926                         }
 927                         expect_void(')');
 928                         break;
 929                 default:
 930                         goto attributes_finished;
 931                 }
 932         }
 933
 934 attributes_finished:
 935         ;
 936 }
 937
 938 #if 0
 939 static designator_t *parse_designation(void)
 940 {
 941         if(token.type != '[' && token.type != '.')
 942                 return NULL;
 943
 944         designator_t *result = NULL;
 945         designator_t *last   = NULL;
 946
 947         while(1) {
 948                 designator_t *designator;
 949                 switch(token.type) {
 950                 case '[':
 951                         designator = allocate_ast_zero(sizeof(designator[0]));
 952                         next_token();
 953                         designator->array_access = parse_constant_expression();
 954                         expect(']');
 955                         break;
 956                 case '.':
 957                         designator = allocate_ast_zero(sizeof(designator[0]));
 958                         next_token();
 959                         if(token.type != T_IDENTIFIER) {
 960                                 parse_error_expected("while parsing designator",
 961                                                      T_IDENTIFIER, 0);
 962                                 return NULL;
 963                         }
 964                         designator->symbol = token.v.symbol;
 965                         next_token();
 966                         break;
 967                 default:
 968                         expect('=');
 969                         return result;
 970                 }
 971
 972                 assert(designator != NULL);
 973                 if(last != NULL) {
 974                         last->next = designator;
 975                 } else {
 976                         result = designator;
 977                 }
 978                 last = designator;
 979         }
 980 }
 981 #endif
 982
 983 static initializer_t *initializer_from_string(array_type_t *type,
 984                                               const char *string)
 985 {
 986         /* TODO: check len vs. size of array type */
 987         (void) type;
 988
 989         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
 990         initializer->string.string = string;
 991
 992         return initializer;
 993 }
 994
 995 static initializer_t *initializer_from_wide_string(array_type_t *const type,
 996                                                    wide_string_t *const string)
 997 {
 998         /* TODO: check len vs. size of array type */
 999         (void) type;
1000
1001         initializer_t *const initializer =
1002                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1003         initializer->wide_string.string = *string;
1004
1005         return initializer;
1006 }
1007
1008 static initializer_t *initializer_from_expression(type_t *type,
1009                                                   expression_t *expression)
1010 {
1011         /* TODO check that expression is a constant expression */
1012
1013         /* § 6.7.8.14/15 char array may be initialized by string literals */
1014         type_t *const expr_type = expression->base.datatype;
1015         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1016                 array_type_t *const array_type   = &type->array;
1017                 type_t       *const element_type = skip_typeref(array_type->element_type);
1018
1019                 if (element_type->kind == TYPE_ATOMIC) {
1020                         switch (expression->kind) {
1021                                 case EXPR_STRING_LITERAL:
1022                                         if (element_type->atomic.akind == ATOMIC_TYPE_CHAR) {
1023                                                 return initializer_from_string(array_type,
1024                                                         expression->string.value);
1025                                         }
1026
1027                                 case EXPR_WIDE_STRING_LITERAL: {
1028                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1029                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
1030                                                 return initializer_from_wide_string(array_type,
1031                                                         &expression->wide_string.value);
1032                                         }
1033                                 }
1034
1035                                 default:
1036                                         break;
1037                         }
1038                 }
1039         }
1040
1041         type_t *expression_type = skip_typeref(expression->base.datatype);
1042         if(is_type_scalar(type) || types_compatible(type, expression_type)) {
1043                 semantic_assign(type, &expression, "initializer");
1044
1045                 initializer_t *result = allocate_initializer_zero(INITIALIZER_VALUE);
1046                 result->value.value   = expression;
1047
1048                 return result;
1049         }
1050
1051         return NULL;
1052 }
1053
1054 static initializer_t *parse_sub_initializer(type_t *type,
1055                                             expression_t *expression,
1056                                             type_t *expression_type);
1057
1058 static initializer_t *parse_sub_initializer_elem(type_t *type)
1059 {
1060         if(token.type == '{') {
1061                 return parse_sub_initializer(type, NULL, NULL);
1062         }
1063
1064         expression_t *expression      = parse_assignment_expression();
1065         type_t       *expression_type = skip_typeref(expression->base.datatype);
1066
1067         return parse_sub_initializer(type, expression, expression_type);
1068 }
1069
1070 static bool had_initializer_brace_warning;
1071
1072 static void skip_designator(void)
1073 {
1074         while(1) {
1075                 if(token.type == '.') {
1076                         next_token();
1077                         if(token.type == T_IDENTIFIER)
1078                                 next_token();
1079                 } else if(token.type == '[') {
1080                         next_token();
1081                         parse_constant_expression();
1082                         if(token.type == ']')
1083                                 next_token();
1084                 } else {
1085                         break;
1086                 }
1087         }
1088 }
1089
1090 static initializer_t *parse_sub_initializer(type_t *type,
1091                                             expression_t *expression,
1092                                             type_t *expression_type)
1093 {
1094         if(is_type_scalar(type)) {
1095                 /* there might be extra {} hierarchies */
1096                 if(token.type == '{') {
1097                         next_token();
1098                         if(!had_initializer_brace_warning) {
1099                                 warningf(HERE, "braces around scalar initializer");
1100                                 had_initializer_brace_warning = true;
1101                         }
1102                         initializer_t *result = parse_sub_initializer(type, NULL, NULL);
1103                         if(token.type == ',') {
1104                                 next_token();
1105                                 /* TODO: warn about excessive elements */
1106                         }
1107                         expect_block('}');
1108                         return result;
1109                 }
1110
1111                 if(expression == NULL) {
1112                         expression = parse_assignment_expression();
1113                 }
1114                 return initializer_from_expression(type, expression);
1115         }
1116
1117         /* does the expression match the currently looked at object to initialize */
1118         if(expression != NULL) {
1119                 initializer_t *result = initializer_from_expression(type, expression);
1120                 if(result != NULL)
1121                         return result;
1122         }
1123
1124         bool read_paren = false;
1125         if(token.type == '{') {
1126                 next_token();
1127                 read_paren = true;
1128         }
1129
1130         /* descend into subtype */
1131         initializer_t  *result = NULL;
1132         initializer_t **elems;
1133         if(is_type_array(type)) {
1134                 array_type_t *array_type   = &type->array;
1135                 type_t       *element_type = array_type->element_type;
1136                 element_type               = skip_typeref(element_type);
1137
1138                 if(token.type == '.') {
1139                         errorf(HERE,
1140                                "compound designator in initializer for array type '%T'",
1141                                type);
1142                         skip_designator();
1143                 }
1144
1145                 initializer_t *sub;
1146                 had_initializer_brace_warning = false;
1147                 if(expression == NULL) {
1148                         sub = parse_sub_initializer_elem(element_type);
1149                 } else {
1150                         sub = parse_sub_initializer(element_type, expression,
1151                                                     expression_type);
1152                 }
1153
1154                 /* didn't match the subtypes -> try the parent type */
1155                 if(sub == NULL) {
1156                         assert(!read_paren);
1157                         return NULL;
1158                 }
1159
1160                 elems = NEW_ARR_F(initializer_t*, 0);
1161                 ARR_APP1(initializer_t*, elems, sub);
1162
1163                 while(true) {
1164                         if(token.type == '}')
1165                                 break;
1166                         expect_block(',');
1167                         if(token.type == '}')
1168                                 break;
1169
1170                         sub = parse_sub_initializer_elem(element_type);
1171                         if(sub == NULL) {
1172                                 /* TODO error, do nicer cleanup */
1173                                 errorf(HERE, "member initializer didn't match");
1174                                 DEL_ARR_F(elems);
1175                                 return NULL;
1176                         }
1177                         ARR_APP1(initializer_t*, elems, sub);
1178                 }
1179         } else {
1180                 assert(is_type_compound(type));
1181                 compound_type_t *compound_type = &type->compound;
1182                 context_t       *context       = &compound_type->declaration->context;
1183
1184                 if(token.type == '[') {
1185                         errorf(HERE,
1186                                "array designator in initializer for compound type '%T'",
1187                                type);
1188                         skip_designator();
1189                 }
1190
1191                 declaration_t *first = context->declarations;
1192                 if(first == NULL)
1193                         return NULL;
1194                 type_t *first_type = first->type;
1195                 first_type         = skip_typeref(first_type);
1196
1197                 initializer_t *sub;
1198                 had_initializer_brace_warning = false;
1199                 if(expression == NULL) {
1200                         sub = parse_sub_initializer_elem(first_type);
1201                 } else {
1202                         sub = parse_sub_initializer(first_type, expression,expression_type);
1203                 }
1204
1205                 /* didn't match the subtypes -> try our parent type */
1206                 if(sub == NULL) {
1207                         assert(!read_paren);
1208                         return NULL;
1209                 }
1210
1211                 elems = NEW_ARR_F(initializer_t*, 0);
1212                 ARR_APP1(initializer_t*, elems, sub);
1213
1214                 declaration_t *iter  = first->next;
1215                 for( ; iter != NULL; iter = iter->next) {
1216                         if(iter->symbol == NULL)
1217                                 continue;
1218                         if(iter->namespc != NAMESPACE_NORMAL)
1219                                 continue;
1220
1221                         if(token.type == '}')
1222                                 break;
1223                         expect_block(',');
1224                         if(token.type == '}')
1225                                 break;
1226
1227                         type_t *iter_type = iter->type;
1228                         iter_type         = skip_typeref(iter_type);
1229
1230                         sub = parse_sub_initializer_elem(iter_type);
1231                         if(sub == NULL) {
1232                                 /* TODO error, do nicer cleanup */
1233                                 errorf(HERE, "member initializer didn't match");
1234                                 DEL_ARR_F(elems);
1235                                 return NULL;
1236                         }
1237                         ARR_APP1(initializer_t*, elems, sub);
1238                 }
1239         }
1240
1241         int    len        = ARR_LEN(elems);
1242         size_t elems_size = sizeof(initializer_t*) * len;
1243
1244         initializer_list_t *init = allocate_ast_zero(sizeof(init[0]) + elems_size);
1245
1246         init->initializer.kind = INITIALIZER_LIST;
1247         init->len              = len;
1248         memcpy(init->initializers, elems, elems_size);
1249         DEL_ARR_F(elems);
1250
1251         result = (initializer_t*) init;
1252
1253         if(read_paren) {
1254                 if(token.type == ',')
1255                         next_token();
1256                 expect('}');
1257         }
1258         return result;
1259 }
1260
1261 static initializer_t *parse_initializer(type_t *type)
1262 {
1263         initializer_t *result;
1264
1265         type = skip_typeref(type);
1266
1267         if(token.type != '{') {
1268                 expression_t  *expression  = parse_assignment_expression();
1269                 initializer_t *initializer = initializer_from_expression(type, expression);
1270                 if(initializer == NULL) {
1271                         errorf(HERE, "initializer expression '%E', type '%T' is incompatible with type '%T'", expression, expression->base.datatype, type);
1272                 }
1273                 return initializer;
1274         }
1275
1276         if(is_type_scalar(type)) {
1277                 /* § 6.7.8.11 */
1278                 eat('{');
1279
1280                 expression_t *expression = parse_assignment_expression();
1281                 result = initializer_from_expression(type, expression);
1282
1283                 if(token.type == ',')
1284                         next_token();
1285
1286                 expect('}');
1287                 return result;
1288         } else {
1289                 result = parse_sub_initializer(type, NULL, NULL);
1290         }
1291
1292         return result;
1293 }
1294
1295 static declaration_t *append_declaration(declaration_t *declaration);
1296
1297 static declaration_t *parse_compound_type_specifier(bool is_struct)
1298 {
1299         if(is_struct) {
1300                 eat(T_struct);
1301         } else {
1302                 eat(T_union);
1303         }
1304
1305         symbol_t      *symbol      = NULL;
1306         declaration_t *declaration = NULL;
1307
1308         if (token.type == T___attribute__) {
1309                 /* TODO */
1310                 parse_attributes();
1311         }
1312
1313         if(token.type == T_IDENTIFIER) {
1314                 symbol = token.v.symbol;
1315                 next_token();
1316
1317                 if(is_struct) {
1318                         declaration = get_declaration(symbol, NAMESPACE_STRUCT);
1319                 } else {
1320                         declaration = get_declaration(symbol, NAMESPACE_UNION);
1321                 }
1322         } else if(token.type != '{') {
1323                 if(is_struct) {
1324                         parse_error_expected("while parsing struct type specifier",
1325                                              T_IDENTIFIER, '{', 0);
1326                 } else {
1327                         parse_error_expected("while parsing union type specifier",
1328                                              T_IDENTIFIER, '{', 0);
1329                 }
1330
1331                 return NULL;
1332         }
1333
1334         if(declaration == NULL) {
1335                 declaration = allocate_ast_zero(sizeof(declaration[0]));
1336
1337                 if(is_struct) {
1338                         declaration->namespc = NAMESPACE_STRUCT;
1339                 } else {
1340                         declaration->namespc = NAMESPACE_UNION;
1341                 }
1342                 declaration->source_position = token.source_position;
1343                 declaration->symbol          = symbol;
1344                 declaration->parent_context  = context;
1345                 if (symbol != NULL) {
1346                         environment_push(declaration);
1347                 }
1348                 append_declaration(declaration);
1349         }
1350
1351         if(token.type == '{') {
1352                 if(declaration->init.is_defined) {
1353                         assert(symbol != NULL);
1354                         errorf(HERE, "multiple definition of '%s %Y'",
1355                                is_struct ? "struct" : "union", symbol);
1356                         declaration->context.declarations = NULL;
1357                 }
1358                 declaration->init.is_defined = true;
1359
1360                 int         top          = environment_top();
1361                 context_t  *last_context = context;
1362                 set_context(&declaration->context);
1363
1364                 parse_compound_type_entries();
1365                 parse_attributes();
1366
1367                 assert(context == &declaration->context);
1368                 set_context(last_context);
1369                 environment_pop_to(top);
1370         }
1371
1372         return declaration;
1373 }
1374
1375 static void parse_enum_entries(enum_type_t *const enum_type)
1376 {
1377         eat('{');
1378
1379         if(token.type == '}') {
1380                 next_token();
1381                 errorf(HERE, "empty enum not allowed");
1382                 return;
1383         }
1384
1385         do {
1386                 declaration_t *entry = allocate_ast_zero(sizeof(entry[0]));
1387
1388                 if(token.type != T_IDENTIFIER) {
1389                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, 0);
1390                         eat_block();
1391                         return;
1392                 }
1393                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
1394                 entry->type            = (type_t*) enum_type;
1395                 entry->symbol          = token.v.symbol;
1396                 entry->source_position = token.source_position;
1397                 next_token();
1398
1399                 if(token.type == '=') {
1400                         next_token();
1401                         entry->init.enum_value = parse_constant_expression();
1402
1403                         /* TODO semantic */
1404                 }
1405
1406                 record_declaration(entry);
1407
1408                 if(token.type != ',')
1409                         break;
1410                 next_token();
1411         } while(token.type != '}');
1412
1413         expect_void('}');
1414 }
1415
1416 static type_t *parse_enum_specifier(void)
1417 {
1418         eat(T_enum);
1419
1420         declaration_t *declaration;
1421         symbol_t      *symbol;
1422
1423         if(token.type == T_IDENTIFIER) {
1424                 symbol = token.v.symbol;
1425                 next_token();
1426
1427                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1428         } else if(token.type != '{') {
1429                 parse_error_expected("while parsing enum type specifier",
1430                                      T_IDENTIFIER, '{', 0);
1431                 return NULL;
1432         } else {
1433                 declaration = NULL;
1434                 symbol      = NULL;
1435         }
1436
1437         if(declaration == NULL) {
1438                 declaration = allocate_ast_zero(sizeof(declaration[0]));
1439
1440                 declaration->namespc       = NAMESPACE_ENUM;
1441                 declaration->source_position = token.source_position;
1442                 declaration->symbol          = symbol;
1443                 declaration->parent_context  = context;
1444         }
1445
1446         type_t *const type      = allocate_type_zero(TYPE_ENUM);
1447         type->enumt.declaration = declaration;
1448
1449         if(token.type == '{') {
1450                 if(declaration->init.is_defined) {
1451                         errorf(HERE, "multiple definitions of enum %Y", symbol);
1452                 }
1453                 if (symbol != NULL) {
1454                         environment_push(declaration);
1455                 }
1456                 append_declaration(declaration);
1457                 declaration->init.is_defined = 1;
1458
1459                 parse_enum_entries(&type->enumt);
1460                 parse_attributes();
1461         }
1462
1463         return type;
1464 }
1465
1466 /**
1467  * if a symbol is a typedef to another type, return true
1468  */
1469 static bool is_typedef_symbol(symbol_t *symbol)
1470 {
1471         const declaration_t *const declaration =
1472                 get_declaration(symbol, NAMESPACE_NORMAL);
1473         return
1474                 declaration != NULL &&
1475                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1476 }
1477
1478 static type_t *parse_typeof(void)
1479 {
1480         eat(T___typeof__);
1481
1482         type_t *type;
1483
1484         expect('(');
1485
1486         expression_t *expression  = NULL;
1487
1488 restart:
1489         switch(token.type) {
1490         case T___extension__:
1491                 /* this can be a prefix to a typename or an expression */
1492                 /* we simply eat it now. */
1493                 do {
1494                         next_token();
1495                 } while(token.type == T___extension__);
1496                 goto restart;
1497
1498         case T_IDENTIFIER:
1499                 if(is_typedef_symbol(token.v.symbol)) {
1500                         type = parse_typename();
1501                 } else {
1502                         expression = parse_expression();
1503                         type       = expression->base.datatype;
1504                 }
1505                 break;
1506
1507         TYPENAME_START
1508                 type = parse_typename();
1509                 break;
1510
1511         default:
1512                 expression = parse_expression();
1513                 type       = expression->base.datatype;
1514                 break;
1515         }
1516
1517         expect(')');
1518
1519         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
1520         typeof_type->typeoft.expression  = expression;
1521         typeof_type->typeoft.typeof_type = type;
1522
1523         return typeof_type;
1524 }
1525
1526 typedef enum {
1527         SPECIFIER_SIGNED    = 1 << 0,
1528         SPECIFIER_UNSIGNED  = 1 << 1,
1529         SPECIFIER_LONG      = 1 << 2,
1530         SPECIFIER_INT       = 1 << 3,
1531         SPECIFIER_DOUBLE    = 1 << 4,
1532         SPECIFIER_CHAR      = 1 << 5,
1533         SPECIFIER_SHORT     = 1 << 6,
1534         SPECIFIER_LONG_LONG = 1 << 7,
1535         SPECIFIER_FLOAT     = 1 << 8,
1536         SPECIFIER_BOOL      = 1 << 9,
1537         SPECIFIER_VOID      = 1 << 10,
1538 #ifdef PROVIDE_COMPLEX
1539         SPECIFIER_COMPLEX   = 1 << 11,
1540         SPECIFIER_IMAGINARY = 1 << 12,
1541 #endif
1542 } specifiers_t;
1543
1544 static type_t *create_builtin_type(symbol_t *const symbol,
1545                                    type_t *const real_type)
1546 {
1547         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
1548         type->builtin.symbol    = symbol;
1549         type->builtin.real_type = real_type;
1550
1551         type_t *result = typehash_insert(type);
1552         if (type != result) {
1553                 free_type(type);
1554         }
1555
1556         return result;
1557 }
1558
1559 static type_t *get_typedef_type(symbol_t *symbol)
1560 {
1561         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1562         if(declaration == NULL
1563                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1564                 return NULL;
1565
1566         type_t *type               = allocate_type_zero(TYPE_TYPEDEF);
1567         type->typedeft.declaration = declaration;
1568
1569         return type;
1570 }
1571
1572 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1573 {
1574         type_t   *type            = NULL;
1575         unsigned  type_qualifiers = 0;
1576         unsigned  type_specifiers = 0;
1577         int       newtype         = 0;
1578
1579         specifiers->source_position = token.source_position;
1580
1581         while(true) {
1582                 switch(token.type) {
1583
1584                 /* storage class */
1585 #define MATCH_STORAGE_CLASS(token, class)                                \
1586                 case token:                                                      \
1587                         if(specifiers->storage_class != STORAGE_CLASS_NONE) {        \
1588                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
1589                         }                                                            \
1590                         specifiers->storage_class = class;                           \
1591                         next_token();                                                \
1592                         break;
1593
1594                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1595                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1596                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1597                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1598                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1599
1600                 case T___thread:
1601                         switch (specifiers->storage_class) {
1602                                 case STORAGE_CLASS_NONE:
1603                                         specifiers->storage_class = STORAGE_CLASS_THREAD;
1604                                         break;
1605
1606                                 case STORAGE_CLASS_EXTERN:
1607                                         specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
1608                                         break;
1609
1610                                 case STORAGE_CLASS_STATIC:
1611                                         specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
1612                                         break;
1613
1614                                 default:
1615                                         errorf(HERE, "multiple storage classes in declaration specifiers");
1616                                         break;
1617                         }
1618                         next_token();
1619                         break;
1620
1621                 /* type qualifiers */
1622 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1623                 case token:                                                     \
1624                         type_qualifiers |= qualifier;                               \
1625                         next_token();                                               \
1626                         break;
1627
1628                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1629                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1630                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1631
1632                 case T___extension__:
1633                         /* TODO */
1634                         next_token();
1635                         break;
1636
1637                 /* type specifiers */
1638 #define MATCH_SPECIFIER(token, specifier, name)                         \
1639                 case token:                                                     \
1640                         next_token();                                               \
1641                         if(type_specifiers & specifier) {                           \
1642                                 errorf(HERE, "multiple " name " type specifiers given"); \
1643                         } else {                                                    \
1644                                 type_specifiers |= specifier;                           \
1645                         }                                                           \
1646                         break;
1647
1648                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
1649                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
1650                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
1651                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
1652                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
1653                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
1654                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
1655                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
1656                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
1657 #ifdef PROVIDE_COMPLEX
1658                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
1659                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
1660 #endif
1661                 case T_forceinline:
1662                         /* only in microsoft mode */
1663                         specifiers->decl_modifiers |= DM_FORCEINLINE;
1664
1665                 case T_inline:
1666                         next_token();
1667                         specifiers->is_inline = true;
1668                         break;
1669
1670                 case T_long:
1671                         next_token();
1672                         if(type_specifiers & SPECIFIER_LONG_LONG) {
1673                                 errorf(HERE, "multiple type specifiers given");
1674                         } else if(type_specifiers & SPECIFIER_LONG) {
1675                                 type_specifiers |= SPECIFIER_LONG_LONG;
1676                         } else {
1677                                 type_specifiers |= SPECIFIER_LONG;
1678                         }
1679                         break;
1680
1681                 /* TODO: if type != NULL for the following rules should issue
1682                  * an error */
1683                 case T_struct: {
1684                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1685
1686                         type->compound.declaration = parse_compound_type_specifier(true);
1687                         break;
1688                 }
1689                 case T_union: {
1690                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1691
1692                         type->compound.declaration = parse_compound_type_specifier(false);
1693                         break;
1694                 }
1695                 case T_enum:
1696                         type = parse_enum_specifier();
1697                         break;
1698                 case T___typeof__:
1699                         type = parse_typeof();
1700                         break;
1701                 case T___builtin_va_list:
1702                         type = duplicate_type(type_valist);
1703                         next_token();
1704                         break;
1705
1706                 case T___attribute__:
1707                         /* TODO */
1708                         parse_attributes();
1709                         break;
1710
1711                 case T_IDENTIFIER: {
1712                         type_t *typedef_type = get_typedef_type(token.v.symbol);
1713
1714                         if(typedef_type == NULL)
1715                                 goto finish_specifiers;
1716
1717                         next_token();
1718                         type = typedef_type;
1719                         break;
1720                 }
1721
1722                 /* function specifier */
1723                 default:
1724                         goto finish_specifiers;
1725                 }
1726         }
1727
1728 finish_specifiers:
1729
1730         if(type == NULL) {
1731                 atomic_type_kind_t atomic_type;
1732
1733                 /* match valid basic types */
1734                 switch(type_specifiers) {
1735                 case SPECIFIER_VOID:
1736                         atomic_type = ATOMIC_TYPE_VOID;
1737                         break;
1738                 case SPECIFIER_CHAR:
1739                         atomic_type = ATOMIC_TYPE_CHAR;
1740                         break;
1741                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
1742                         atomic_type = ATOMIC_TYPE_SCHAR;
1743                         break;
1744                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
1745                         atomic_type = ATOMIC_TYPE_UCHAR;
1746                         break;
1747                 case SPECIFIER_SHORT:
1748                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
1749                 case SPECIFIER_SHORT | SPECIFIER_INT:
1750                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1751                         atomic_type = ATOMIC_TYPE_SHORT;
1752                         break;
1753                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
1754                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1755                         atomic_type = ATOMIC_TYPE_USHORT;
1756                         break;
1757                 case SPECIFIER_INT:
1758                 case SPECIFIER_SIGNED:
1759                 case SPECIFIER_SIGNED | SPECIFIER_INT:
1760                         atomic_type = ATOMIC_TYPE_INT;
1761                         break;
1762                 case SPECIFIER_UNSIGNED:
1763                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
1764                         atomic_type = ATOMIC_TYPE_UINT;
1765                         break;
1766                 case SPECIFIER_LONG:
1767                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
1768                 case SPECIFIER_LONG | SPECIFIER_INT:
1769                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1770                         atomic_type = ATOMIC_TYPE_LONG;
1771                         break;
1772                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
1773                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1774                         atomic_type = ATOMIC_TYPE_ULONG;
1775                         break;
1776                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1777                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1778                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
1779                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1780                         | SPECIFIER_INT:
1781                         atomic_type = ATOMIC_TYPE_LONGLONG;
1782                         break;
1783                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1784                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1785                         | SPECIFIER_INT:
1786                         atomic_type = ATOMIC_TYPE_ULONGLONG;
1787                         break;
1788                 case SPECIFIER_FLOAT:
1789                         atomic_type = ATOMIC_TYPE_FLOAT;
1790                         break;
1791                 case SPECIFIER_DOUBLE:
1792                         atomic_type = ATOMIC_TYPE_DOUBLE;
1793                         break;
1794                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
1795                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
1796                         break;
1797                 case SPECIFIER_BOOL:
1798                         atomic_type = ATOMIC_TYPE_BOOL;
1799                         break;
1800 #ifdef PROVIDE_COMPLEX
1801                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
1802                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
1803                         break;
1804                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1805                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
1806                         break;
1807                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1808                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
1809                         break;
1810                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
1811                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
1812                         break;
1813                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1814                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
1815                         break;
1816                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1817                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
1818                         break;
1819 #endif
1820                 default:
1821                         /* invalid specifier combination, give an error message */
1822                         if(type_specifiers == 0) {
1823                                 if (! strict_mode) {
1824                                         warningf(HERE, "no type specifiers in declaration, using int");
1825                                         atomic_type = ATOMIC_TYPE_INT;
1826                                         break;
1827                                 } else {
1828                                         errorf(HERE, "no type specifiers given in declaration");
1829                                 }
1830                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
1831                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
1832                                 errorf(HERE, "signed and unsigned specifiers gives");
1833                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
1834                                 errorf(HERE, "only integer types can be signed or unsigned");
1835                         } else {
1836                                 errorf(HERE, "multiple datatypes in declaration");
1837                         }
1838                         atomic_type = ATOMIC_TYPE_INVALID;
1839                 }
1840
1841                 type               = allocate_type_zero(TYPE_ATOMIC);
1842                 type->atomic.akind = atomic_type;
1843                 newtype            = 1;
1844         } else {
1845                 if(type_specifiers != 0) {
1846                         errorf(HERE, "multiple datatypes in declaration");
1847                 }
1848         }
1849
1850         type->base.qualifiers = type_qualifiers;
1851
1852         type_t *result = typehash_insert(type);
1853         if(newtype && result != type) {
1854                 free_type(type);
1855         }
1856
1857         specifiers->type = result;
1858 }
1859
1860 static type_qualifiers_t parse_type_qualifiers(void)
1861 {
1862         type_qualifiers_t type_qualifiers = TYPE_QUALIFIER_NONE;
1863
1864         while(true) {
1865                 switch(token.type) {
1866                 /* type qualifiers */
1867                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1868                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1869                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1870
1871                 default:
1872                         return type_qualifiers;
1873                 }
1874         }
1875 }
1876
1877 static declaration_t *parse_identifier_list(void)
1878 {
1879         declaration_t *declarations     = NULL;
1880         declaration_t *last_declaration = NULL;
1881         do {
1882                 declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
1883
1884                 declaration->source_position = token.source_position;
1885                 declaration->symbol          = token.v.symbol;
1886                 next_token();
1887
1888                 if(last_declaration != NULL) {
1889                         last_declaration->next = declaration;
1890                 } else {
1891                         declarations = declaration;
1892                 }
1893                 last_declaration = declaration;
1894
1895                 if(token.type != ',')
1896                         break;
1897                 next_token();
1898         } while(token.type == T_IDENTIFIER);
1899
1900         return declarations;
1901 }
1902
1903 static void semantic_parameter(declaration_t *declaration)
1904 {
1905         /* TODO: improve error messages */
1906
1907         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
1908                 errorf(HERE, "typedef not allowed in parameter list");
1909         } else if(declaration->storage_class != STORAGE_CLASS_NONE
1910                         && declaration->storage_class != STORAGE_CLASS_REGISTER) {
1911                 errorf(HERE, "parameter may only have none or register storage class");
1912         }
1913
1914         type_t *orig_type = declaration->type;
1915         if(orig_type == NULL)
1916                 return;
1917         type_t *type = skip_typeref(orig_type);
1918
1919         /* Array as last part of a parameter type is just syntactic sugar.  Turn it
1920          * into a pointer. § 6.7.5.3 (7) */
1921         if (is_type_array(type)) {
1922                 const array_type_t *arr_type     = &type->array;
1923                 type_t             *element_type = arr_type->element_type;
1924
1925                 type = make_pointer_type(element_type, type->base.qualifiers);
1926
1927                 declaration->type = type;
1928         }
1929
1930         if(is_type_incomplete(type)) {
1931                 errorf(HERE, "incomplete type ('%T') not allowed for parameter '%Y'",
1932                        orig_type, declaration->symbol);
1933         }
1934 }
1935
1936 static declaration_t *parse_parameter(void)
1937 {
1938         declaration_specifiers_t specifiers;
1939         memset(&specifiers, 0, sizeof(specifiers));
1940
1941         parse_declaration_specifiers(&specifiers);
1942
1943         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
1944
1945         semantic_parameter(declaration);
1946
1947         return declaration;
1948 }
1949
1950 static declaration_t *parse_parameters(function_type_t *type)
1951 {
1952         if(token.type == T_IDENTIFIER) {
1953                 symbol_t *symbol = token.v.symbol;
1954                 if(!is_typedef_symbol(symbol)) {
1955                         type->kr_style_parameters = true;
1956                         return parse_identifier_list();
1957                 }
1958         }
1959
1960         if(token.type == ')') {
1961                 type->unspecified_parameters = 1;
1962                 return NULL;
1963         }
1964         if(token.type == T_void && look_ahead(1)->type == ')') {
1965                 next_token();
1966                 return NULL;
1967         }
1968
1969         declaration_t        *declarations = NULL;
1970         declaration_t        *declaration;
1971         declaration_t        *last_declaration = NULL;
1972         function_parameter_t *parameter;
1973         function_parameter_t *last_parameter = NULL;
1974
1975         while(true) {
1976                 switch(token.type) {
1977                 case T_DOTDOTDOT:
1978                         next_token();
1979                         type->variadic = 1;
1980                         return declarations;
1981
1982                 case T_IDENTIFIER:
1983                 case T___extension__:
1984                 DECLARATION_START
1985                         declaration = parse_parameter();
1986
1987                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
1988                         memset(parameter, 0, sizeof(parameter[0]));
1989                         parameter->type = declaration->type;
1990
1991                         if(last_parameter != NULL) {
1992                                 last_declaration->next = declaration;
1993                                 last_parameter->next   = parameter;
1994                         } else {
1995                                 type->parameters = parameter;
1996                                 declarations     = declaration;
1997                         }
1998                         last_parameter   = parameter;
1999                         last_declaration = declaration;
2000                         break;
2001
2002                 default:
2003                         return declarations;
2004                 }
2005                 if(token.type != ',')
2006                         return declarations;
2007                 next_token();
2008         }
2009 }
2010
2011 typedef enum {
2012         CONSTRUCT_INVALID,
2013         CONSTRUCT_POINTER,
2014         CONSTRUCT_FUNCTION,
2015         CONSTRUCT_ARRAY
2016 } construct_type_type_t;
2017
2018 typedef struct construct_type_t construct_type_t;
2019 struct construct_type_t {
2020         construct_type_type_t  type;
2021         construct_type_t      *next;
2022 };
2023
2024 typedef struct parsed_pointer_t parsed_pointer_t;
2025 struct parsed_pointer_t {
2026         construct_type_t  construct_type;
2027         type_qualifiers_t type_qualifiers;
2028 };
2029
2030 typedef struct construct_function_type_t construct_function_type_t;
2031 struct construct_function_type_t {
2032         construct_type_t  construct_type;
2033         type_t           *function_type;
2034 };
2035
2036 typedef struct parsed_array_t parsed_array_t;
2037 struct parsed_array_t {
2038         construct_type_t  construct_type;
2039         type_qualifiers_t type_qualifiers;
2040         bool              is_static;
2041         bool              is_variable;
2042         expression_t     *size;
2043 };
2044
2045 typedef struct construct_base_type_t construct_base_type_t;
2046 struct construct_base_type_t {
2047         construct_type_t  construct_type;
2048         type_t           *type;
2049 };
2050
2051 static construct_type_t *parse_pointer_declarator(void)
2052 {
2053         eat('*');
2054
2055         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
2056         memset(pointer, 0, sizeof(pointer[0]));
2057         pointer->construct_type.type = CONSTRUCT_POINTER;
2058         pointer->type_qualifiers     = parse_type_qualifiers();
2059
2060         return (construct_type_t*) pointer;
2061 }
2062
2063 static construct_type_t *parse_array_declarator(void)
2064 {
2065         eat('[');
2066
2067         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
2068         memset(array, 0, sizeof(array[0]));
2069         array->construct_type.type = CONSTRUCT_ARRAY;
2070
2071         if(token.type == T_static) {
2072                 array->is_static = true;
2073                 next_token();
2074         }
2075
2076         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
2077         if(type_qualifiers != 0) {
2078                 if(token.type == T_static) {
2079                         array->is_static = true;
2080                         next_token();
2081                 }
2082         }
2083         array->type_qualifiers = type_qualifiers;
2084
2085         if(token.type == '*' && look_ahead(1)->type == ']') {
2086                 array->is_variable = true;
2087                 next_token();
2088         } else if(token.type != ']') {
2089                 array->size = parse_assignment_expression();
2090         }
2091
2092         expect(']');
2093
2094         return (construct_type_t*) array;
2095 }
2096
2097 static construct_type_t *parse_function_declarator(declaration_t *declaration)
2098 {
2099         eat('(');
2100
2101         type_t *type = allocate_type_zero(TYPE_FUNCTION);
2102
2103         declaration_t *parameters = parse_parameters(&type->function);
2104         if(declaration != NULL) {
2105                 declaration->context.declarations = parameters;
2106         }
2107
2108         construct_function_type_t *construct_function_type =
2109                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
2110         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
2111         construct_function_type->construct_type.type = CONSTRUCT_FUNCTION;
2112         construct_function_type->function_type       = type;
2113
2114         expect(')');
2115
2116         return (construct_type_t*) construct_function_type;
2117 }
2118
2119 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
2120                 bool may_be_abstract)
2121 {
2122         /* construct a single linked list of construct_type_t's which describe
2123          * how to construct the final declarator type */
2124         construct_type_t *first = NULL;
2125         construct_type_t *last  = NULL;
2126
2127         /* pointers */
2128         while(token.type == '*') {
2129                 construct_type_t *type = parse_pointer_declarator();
2130
2131                 if(last == NULL) {
2132                         first = type;
2133                         last  = type;
2134                 } else {
2135                         last->next = type;
2136                         last       = type;
2137                 }
2138         }
2139
2140         /* TODO: find out if this is correct */
2141         parse_attributes();
2142
2143         construct_type_t *inner_types = NULL;
2144
2145         switch(token.type) {
2146         case T_IDENTIFIER:
2147                 if(declaration == NULL) {
2148                         errorf(HERE, "no identifier expected in typename");
2149                 } else {
2150                         declaration->symbol          = token.v.symbol;
2151                         declaration->source_position = token.source_position;
2152                 }
2153                 next_token();
2154                 break;
2155         case '(':
2156                 next_token();
2157                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
2158                 expect(')');
2159                 break;
2160         default:
2161                 if(may_be_abstract)
2162                         break;
2163                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
2164                 /* avoid a loop in the outermost scope, because eat_statement doesn't
2165                  * eat '}' */
2166                 if(token.type == '}' && current_function == NULL) {
2167                         next_token();
2168                 } else {
2169                         eat_statement();
2170                 }
2171                 return NULL;
2172         }
2173
2174         construct_type_t *p = last;
2175
2176         while(true) {
2177                 construct_type_t *type;
2178                 switch(token.type) {
2179                 case '(':
2180                         type = parse_function_declarator(declaration);
2181                         break;
2182                 case '[':
2183                         type = parse_array_declarator();
2184                         break;
2185                 default:
2186                         goto declarator_finished;
2187                 }
2188
2189                 /* insert in the middle of the list (behind p) */
2190                 if(p != NULL) {
2191                         type->next = p->next;
2192                         p->next    = type;
2193                 } else {
2194                         type->next = first;
2195                         first      = type;
2196                 }
2197                 if(last == p) {
2198                         last = type;
2199                 }
2200         }
2201
2202 declarator_finished:
2203         parse_attributes();
2204
2205         /* append inner_types at the end of the list, we don't to set last anymore
2206          * as it's not needed anymore */
2207         if(last == NULL) {
2208                 assert(first == NULL);
2209                 first = inner_types;
2210         } else {
2211                 last->next = inner_types;
2212         }
2213
2214         return first;
2215 }
2216
2217 static type_t *construct_declarator_type(construct_type_t *construct_list,
2218                                          type_t *type)
2219 {
2220         construct_type_t *iter = construct_list;
2221         for( ; iter != NULL; iter = iter->next) {
2222                 switch(iter->type) {
2223                 case CONSTRUCT_INVALID:
2224                         panic("invalid type construction found");
2225                 case CONSTRUCT_FUNCTION: {
2226                         construct_function_type_t *construct_function_type
2227                                 = (construct_function_type_t*) iter;
2228
2229                         type_t *function_type = construct_function_type->function_type;
2230
2231                         function_type->function.return_type = type;
2232
2233                         type = function_type;
2234                         break;
2235                 }
2236
2237                 case CONSTRUCT_POINTER: {
2238                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
2239                         type_t           *pointer_type   = allocate_type_zero(TYPE_POINTER);
2240                         pointer_type->pointer.points_to  = type;
2241                         pointer_type->base.qualifiers    = parsed_pointer->type_qualifiers;
2242
2243                         type = pointer_type;
2244                         break;
2245                 }
2246
2247                 case CONSTRUCT_ARRAY: {
2248                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
2249                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
2250
2251                         array_type->base.qualifiers    = parsed_array->type_qualifiers;
2252                         array_type->array.element_type = type;
2253                         array_type->array.is_static    = parsed_array->is_static;
2254                         array_type->array.is_variable  = parsed_array->is_variable;
2255                         array_type->array.size         = parsed_array->size;
2256
2257                         type = array_type;
2258                         break;
2259                 }
2260                 }
2261
2262                 type_t *hashed_type = typehash_insert(type);
2263                 if(hashed_type != type) {
2264                         /* the function type was constructed earlier freeing it here will
2265                          * destroy other types... */
2266                         if(iter->type != CONSTRUCT_FUNCTION) {
2267                                 free_type(type);
2268                         }
2269                         type = hashed_type;
2270                 }
2271         }
2272
2273         return type;
2274 }
2275
2276 static declaration_t *parse_declarator(
2277                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
2278 {
2279         type_t        *type         = specifiers->type;
2280         declaration_t *declaration  = allocate_ast_zero(sizeof(declaration[0]));
2281         declaration->storage_class  = specifiers->storage_class;
2282         declaration->modifiers      = specifiers->decl_modifiers;
2283         declaration->is_inline      = specifiers->is_inline;
2284
2285         construct_type_t *construct_type
2286                 = parse_inner_declarator(declaration, may_be_abstract);
2287         declaration->type = construct_declarator_type(construct_type, type);
2288
2289         if(construct_type != NULL) {
2290                 obstack_free(&temp_obst, construct_type);
2291         }
2292
2293         return declaration;
2294 }
2295
2296 static type_t *parse_abstract_declarator(type_t *base_type)
2297 {
2298         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2299
2300         type_t *result = construct_declarator_type(construct_type, base_type);
2301         if(construct_type != NULL) {
2302                 obstack_free(&temp_obst, construct_type);
2303         }
2304
2305         return result;
2306 }
2307
2308 static declaration_t *append_declaration(declaration_t* const declaration)
2309 {
2310         if (last_declaration != NULL) {
2311                 last_declaration->next = declaration;
2312         } else {
2313                 context->declarations = declaration;
2314         }
2315         last_declaration = declaration;
2316         return declaration;
2317 }
2318
2319 static declaration_t *internal_record_declaration(
2320         declaration_t *const declaration,
2321         const bool is_function_definition)
2322 {
2323         const symbol_t *const symbol  = declaration->symbol;
2324         const namespace_t     namespc = (namespace_t)declaration->namespc;
2325
2326         const type_t *const type = skip_typeref(declaration->type);
2327         if (is_type_function(type) && type->function.unspecified_parameters) {
2328                 warningf(declaration->source_position,
2329                          "function declaration '%#T' is not a prototype",
2330                          type, declaration->symbol);
2331         }
2332
2333         declaration_t *const previous_declaration = get_declaration(symbol, namespc);
2334         assert(declaration != previous_declaration);
2335         if (previous_declaration != NULL
2336                         && previous_declaration->parent_context == context) {
2337                 /* can happen for K&R style declarations */
2338                 if(previous_declaration->type == NULL) {
2339                         previous_declaration->type = declaration->type;
2340                 }
2341
2342                 const type_t *const prev_type = skip_typeref(previous_declaration->type);
2343                 if (!types_compatible(type, prev_type)) {
2344                         errorf(declaration->source_position,
2345                                 "declaration '%#T' is incompatible with previous declaration '%#T'",
2346                                 type, symbol, previous_declaration->type, symbol);
2347                         errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
2348                 } else {
2349                         unsigned old_storage_class = previous_declaration->storage_class;
2350                         unsigned new_storage_class = declaration->storage_class;
2351
2352                         /* pretend no storage class means extern for function declarations
2353                          * (except if the previous declaration is neither none nor extern) */
2354                         if (is_type_function(type)) {
2355                                 switch (old_storage_class) {
2356                                         case STORAGE_CLASS_NONE:
2357                                                 old_storage_class = STORAGE_CLASS_EXTERN;
2358
2359                                         case STORAGE_CLASS_EXTERN:
2360                                                 if (new_storage_class == STORAGE_CLASS_NONE && !is_function_definition) {
2361                                                         new_storage_class = STORAGE_CLASS_EXTERN;
2362                                                 }
2363                                                 break;
2364
2365                                         default: break;
2366                                 }
2367                         }
2368
2369                         if (old_storage_class == STORAGE_CLASS_EXTERN &&
2370                             new_storage_class == STORAGE_CLASS_EXTERN) {
2371 warn_redundant_declaration:
2372                                         warningf(declaration->source_position, "redundant declaration for '%Y'", symbol);
2373                                         warningf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
2374                         } else if (current_function == NULL) {
2375                                 if (old_storage_class != STORAGE_CLASS_STATIC &&
2376                                     new_storage_class == STORAGE_CLASS_STATIC) {
2377                                         errorf(declaration->source_position, "static declaration of '%Y' follows non-static declaration", symbol);
2378                                         errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
2379                                 } else {
2380                                         if (old_storage_class != STORAGE_CLASS_EXTERN) {
2381                                                 goto warn_redundant_declaration;
2382                                         }
2383                                         if (new_storage_class == STORAGE_CLASS_NONE) {
2384                                                 previous_declaration->storage_class = STORAGE_CLASS_NONE;
2385                                         }
2386                                 }
2387                         } else {
2388                                 if (old_storage_class == new_storage_class) {
2389                                         errorf(declaration->source_position, "redeclaration of '%Y'", symbol);
2390                                 } else {
2391                                         errorf(declaration->source_position, "redeclaration of '%Y' with different linkage", symbol);
2392                                 }
2393                                 errorf(previous_declaration->source_position, "previous declaration of '%Y' was here", symbol);
2394                         }
2395                 }
2396                 return previous_declaration;
2397         }
2398
2399         assert(declaration->parent_context == NULL);
2400         assert(declaration->symbol != NULL);
2401         assert(context != NULL);
2402
2403         declaration->parent_context = context;
2404
2405         environment_push(declaration);
2406         return append_declaration(declaration);
2407 }
2408
2409 static declaration_t *record_declaration(declaration_t *declaration)
2410 {
2411         return internal_record_declaration(declaration, false);
2412 }
2413
2414 static declaration_t *record_function_definition(declaration_t *const declaration)
2415 {
2416         return internal_record_declaration(declaration, true);
2417 }
2418
2419 static void parser_error_multiple_definition(declaration_t *declaration,
2420                 const source_position_t source_position)
2421 {
2422         errorf(source_position, "multiple definition of symbol '%Y'",
2423                declaration->symbol);
2424         errorf(declaration->source_position,
2425                "this is the location of the previous definition.");
2426 }
2427
2428 static bool is_declaration_specifier(const token_t *token,
2429                                      bool only_type_specifiers)
2430 {
2431         switch(token->type) {
2432                 TYPE_SPECIFIERS
2433                         return true;
2434                 case T_IDENTIFIER:
2435                         return is_typedef_symbol(token->v.symbol);
2436
2437                 case T___extension__:
2438                 STORAGE_CLASSES
2439                 TYPE_QUALIFIERS
2440                         return !only_type_specifiers;
2441
2442                 default:
2443                         return false;
2444         }
2445 }
2446
2447 static void parse_init_declarator_rest(declaration_t *declaration)
2448 {
2449         eat('=');
2450
2451         type_t *orig_type = declaration->type;
2452         type_t *type      = NULL;
2453         if(orig_type != NULL)
2454                 type = skip_typeref(orig_type);
2455
2456         if(declaration->init.initializer != NULL) {
2457                 parser_error_multiple_definition(declaration, token.source_position);
2458         }
2459
2460         initializer_t *initializer = parse_initializer(type);
2461
2462         /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
2463          * the array type size */
2464         if(type != NULL && is_type_array(type) && initializer != NULL) {
2465                 array_type_t *array_type = &type->array;
2466
2467                 if(array_type->size == NULL) {
2468                         expression_t *cnst = allocate_expression_zero(EXPR_CONST);
2469
2470                         cnst->base.datatype = type_size_t;
2471
2472                         switch (initializer->kind) {
2473                                 case INITIALIZER_LIST: {
2474                                         initializer_list_t *const list = &initializer->list;
2475                                         cnst->conste.v.int_value = list->len;
2476                                         break;
2477                                 }
2478
2479                                 case INITIALIZER_STRING: {
2480                                         initializer_string_t *const string = &initializer->string;
2481                                         cnst->conste.v.int_value = strlen(string->string) + 1;
2482                                         break;
2483                                 }
2484
2485                                 case INITIALIZER_WIDE_STRING: {
2486                                         initializer_wide_string_t *const string = &initializer->wide_string;
2487                                         cnst->conste.v.int_value = string->string.size;
2488                                         break;
2489                                 }
2490
2491                                 default:
2492                                         panic("invalid initializer type");
2493                         }
2494
2495                         array_type->size = cnst;
2496                 }
2497         }
2498
2499         if(type != NULL && is_type_function(type)) {
2500                 errorf(declaration->source_position,
2501                        "initializers not allowed for function types at declator '%Y' (type '%T')",
2502                        declaration->symbol, orig_type);
2503         } else {
2504                 declaration->init.initializer = initializer;
2505         }
2506 }
2507
2508 /* parse rest of a declaration without any declarator */
2509 static void parse_anonymous_declaration_rest(
2510                 const declaration_specifiers_t *specifiers,
2511                 parsed_declaration_func finished_declaration)
2512 {
2513         eat(';');
2514
2515         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
2516
2517         declaration->type            = specifiers->type;
2518         declaration->storage_class   = specifiers->storage_class;
2519         declaration->source_position = specifiers->source_position;
2520
2521         if (declaration->storage_class != STORAGE_CLASS_NONE) {
2522                 warningf(declaration->source_position, "useless storage class in empty declaration");
2523         }
2524
2525         type_t *type = declaration->type;
2526         switch (type->kind) {
2527                 case TYPE_COMPOUND_STRUCT:
2528                 case TYPE_COMPOUND_UNION: {
2529                         const compound_type_t *compound_type = &type->compound;
2530                         if (compound_type->declaration->symbol == NULL) {
2531                                 warningf(declaration->source_position, "unnamed struct/union that defines no instances");
2532                         }
2533                         break;
2534                 }
2535
2536                 case TYPE_ENUM:
2537                         break;
2538
2539                 default:
2540                         warningf(declaration->source_position, "empty declaration");
2541                         break;
2542         }
2543
2544         finished_declaration(declaration);
2545 }
2546
2547 static void parse_declaration_rest(declaration_t *ndeclaration,
2548                 const declaration_specifiers_t *specifiers,
2549                 parsed_declaration_func finished_declaration)
2550 {
2551         while(true) {
2552                 declaration_t *declaration = finished_declaration(ndeclaration);
2553
2554                 type_t *orig_type = declaration->type;
2555                 type_t *type      = skip_typeref(orig_type);
2556
2557                 if(type->kind != TYPE_FUNCTION && declaration->is_inline) {
2558                         warningf(declaration->source_position,
2559                                  "variable '%Y' declared 'inline'\n", declaration->symbol);
2560                 }
2561
2562                 if(token.type == '=') {
2563                         parse_init_declarator_rest(declaration);
2564                 }
2565
2566                 if(token.type != ',')
2567                         break;
2568                 eat(',');
2569
2570                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
2571         }
2572         expect_void(';');
2573 }
2574
2575 static declaration_t *finished_kr_declaration(declaration_t *declaration)
2576 {
2577         symbol_t *symbol  = declaration->symbol;
2578         if(symbol == NULL) {
2579                 errorf(HERE, "anonymous declaration not valid as function parameter");
2580                 return declaration;
2581         }
2582         namespace_t namespc = (namespace_t) declaration->namespc;
2583         if(namespc != NAMESPACE_NORMAL) {
2584                 return record_declaration(declaration);
2585         }
2586
2587         declaration_t *previous_declaration = get_declaration(symbol, namespc);
2588         if(previous_declaration == NULL ||
2589                         previous_declaration->parent_context != context) {
2590                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
2591                        symbol);
2592                 return declaration;
2593         }
2594
2595         if(previous_declaration->type == NULL) {
2596                 previous_declaration->type           = declaration->type;
2597                 previous_declaration->storage_class  = declaration->storage_class;
2598                 previous_declaration->parent_context = context;
2599                 return previous_declaration;
2600         } else {
2601                 return record_declaration(declaration);
2602         }
2603 }
2604
2605 static void parse_declaration(parsed_declaration_func finished_declaration)
2606 {
2607         declaration_specifiers_t specifiers;
2608         memset(&specifiers, 0, sizeof(specifiers));
2609         parse_declaration_specifiers(&specifiers);
2610
2611         if(token.type == ';') {
2612                 parse_anonymous_declaration_rest(&specifiers, finished_declaration);
2613         } else {
2614                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2615                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
2616         }
2617 }
2618
2619 static void parse_kr_declaration_list(declaration_t *declaration)
2620 {
2621         type_t *type = skip_typeref(declaration->type);
2622         if(!is_type_function(type))
2623                 return;
2624
2625         if(!type->function.kr_style_parameters)
2626                 return;
2627
2628         /* push function parameters */
2629         int         top          = environment_top();
2630         context_t  *last_context = context;
2631         set_context(&declaration->context);
2632
2633         declaration_t *parameter = declaration->context.declarations;
2634         for( ; parameter != NULL; parameter = parameter->next) {
2635                 assert(parameter->parent_context == NULL);
2636                 parameter->parent_context = context;
2637                 environment_push(parameter);
2638         }
2639
2640         /* parse declaration list */
2641         while(is_declaration_specifier(&token, false)) {
2642                 parse_declaration(finished_kr_declaration);
2643         }
2644
2645         /* pop function parameters */
2646         assert(context == &declaration->context);
2647         set_context(last_context);
2648         environment_pop_to(top);
2649
2650         /* update function type */
2651         type_t *new_type = duplicate_type(type);
2652         new_type->function.kr_style_parameters = false;
2653
2654         function_parameter_t *parameters     = NULL;
2655         function_parameter_t *last_parameter = NULL;
2656
2657         declaration_t *parameter_declaration = declaration->context.declarations;
2658         for( ; parameter_declaration != NULL;
2659                         parameter_declaration = parameter_declaration->next) {
2660                 type_t *parameter_type = parameter_declaration->type;
2661                 if(parameter_type == NULL) {
2662                         if (strict_mode) {
2663                                 errorf(HERE, "no type specified for function parameter '%Y'",
2664                                        parameter_declaration->symbol);
2665                         } else {
2666                                 warningf(HERE, "no type specified for function parameter '%Y', using int",
2667                                          parameter_declaration->symbol);
2668                                 parameter_type              = type_int;
2669                                 parameter_declaration->type = parameter_type;
2670                         }
2671                 }
2672
2673                 semantic_parameter(parameter_declaration);
2674                 parameter_type = parameter_declaration->type;
2675
2676                 function_parameter_t *function_parameter
2677                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
2678                 memset(function_parameter, 0, sizeof(function_parameter[0]));
2679
2680                 function_parameter->type = parameter_type;
2681                 if(last_parameter != NULL) {
2682                         last_parameter->next = function_parameter;
2683                 } else {
2684                         parameters = function_parameter;
2685                 }
2686                 last_parameter = function_parameter;
2687         }
2688         new_type->function.parameters = parameters;
2689
2690         type = typehash_insert(new_type);
2691         if(type != new_type) {
2692                 obstack_free(type_obst, new_type);
2693         }
2694
2695         declaration->type = type;
2696 }
2697
2698 /**
2699  * Check if all labels are defined in the current function.
2700  */
2701 static void check_for_missing_labels(void)
2702 {
2703         const goto_statement_t *goto_statement, *next;
2704
2705         for (goto_statement = goto_list;
2706              goto_statement != NULL;
2707              goto_statement = next) {
2708                  const declaration_t *label = goto_statement->label;
2709
2710                  if (label->source_position.input_name == NULL) {
2711                          errorf(goto_statement->statement.source_position,
2712                                  "label '%Y' used but not defined", label->symbol);
2713                  }
2714         }
2715         goto_list = NULL;
2716 }
2717
2718 static void parse_external_declaration(void)
2719 {
2720         /* function-definitions and declarations both start with declaration
2721          * specifiers */
2722         declaration_specifiers_t specifiers;
2723         memset(&specifiers, 0, sizeof(specifiers));
2724         parse_declaration_specifiers(&specifiers);
2725
2726         /* must be a declaration */
2727         if(token.type == ';') {
2728                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
2729                 return;
2730         }
2731
2732         /* declarator is common to both function-definitions and declarations */
2733         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2734
2735         /* must be a declaration */
2736         if(token.type == ',' || token.type == '=' || token.type == ';') {
2737                 parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
2738                 return;
2739         }
2740
2741         /* must be a function definition */
2742         parse_kr_declaration_list(ndeclaration);
2743
2744         if(token.type != '{') {
2745                 parse_error_expected("while parsing function definition", '{', 0);
2746                 eat_statement();
2747                 return;
2748         }
2749
2750         type_t *type = ndeclaration->type;
2751         if(type == NULL) {
2752                 eat_block();
2753                 return;
2754         }
2755
2756         /* note that we don't skip typerefs: the standard doesn't allow them here
2757          * (so we can't use is_type_function here) */
2758         if(type->kind != TYPE_FUNCTION) {
2759                 errorf(HERE, "declarator '%#T' has a body but is not a function type",
2760                        type, ndeclaration->symbol);
2761                 eat_block();
2762                 return;
2763         }
2764
2765         /* § 6.7.5.3 (14) a function definition with () means no
2766          * parameters (and not unspecified parameters) */
2767         if(type->function.unspecified_parameters) {
2768                 type_t *duplicate = duplicate_type(type);
2769                 duplicate->function.unspecified_parameters = false;
2770
2771                 type = typehash_insert(duplicate);
2772                 if(type != duplicate) {
2773                         obstack_free(type_obst, duplicate);
2774                 }
2775                 ndeclaration->type = type;
2776         }
2777
2778         declaration_t *const declaration = record_function_definition(ndeclaration);
2779         if(ndeclaration != declaration) {
2780                 declaration->context = ndeclaration->context;
2781         }
2782         type = skip_typeref(declaration->type);
2783
2784         /* push function parameters and switch context */
2785         int         top          = environment_top();
2786         context_t  *last_context = context;
2787         set_context(&declaration->context);
2788
2789         declaration_t *parameter = declaration->context.declarations;
2790         for( ; parameter != NULL; parameter = parameter->next) {
2791                 if(parameter->parent_context == &ndeclaration->context) {
2792                         parameter->parent_context = context;
2793                 }
2794                 assert(parameter->parent_context == NULL
2795                                 || parameter->parent_context == context);
2796                 parameter->parent_context = context;
2797                 environment_push(parameter);
2798         }
2799
2800         if(declaration->init.statement != NULL) {
2801                 parser_error_multiple_definition(declaration, token.source_position);
2802                 eat_block();
2803                 goto end_of_parse_external_declaration;
2804         } else {
2805                 /* parse function body */
2806                 int            label_stack_top      = label_top();
2807                 declaration_t *old_current_function = current_function;
2808                 current_function                    = declaration;
2809
2810                 declaration->init.statement = parse_compound_statement();
2811                 check_for_missing_labels();
2812
2813                 assert(current_function == declaration);
2814                 current_function = old_current_function;
2815                 label_pop_to(label_stack_top);
2816         }
2817
2818 end_of_parse_external_declaration:
2819         assert(context == &declaration->context);
2820         set_context(last_context);
2821         environment_pop_to(top);
2822 }
2823
2824 static type_t *make_bitfield_type(type_t *base, expression_t *size)
2825 {
2826         type_t *type        = allocate_type_zero(TYPE_BITFIELD);
2827         type->bitfield.base = base;
2828         type->bitfield.size = size;
2829
2830         return type;
2831 }
2832
2833 static void parse_struct_declarators(const declaration_specifiers_t *specifiers)
2834 {
2835         /* TODO: check constraints for struct declarations (in specifiers) */
2836         while(1) {
2837                 declaration_t *declaration;
2838
2839                 if(token.type == ':') {
2840                         next_token();
2841
2842                         type_t *base_type = specifiers->type;
2843                         expression_t *size = parse_constant_expression();
2844
2845                         type_t *type = make_bitfield_type(base_type, size);
2846
2847                         declaration = allocate_ast_zero(sizeof(declaration[0]));
2848
2849                         declaration->namespc         = NAMESPACE_NORMAL;
2850                         declaration->storage_class   = STORAGE_CLASS_NONE;
2851                         declaration->source_position = token.source_position;
2852                         declaration->modifiers       = specifiers->decl_modifiers;
2853                         declaration->type            = type;
2854
2855                         record_declaration(declaration);
2856                 } else {
2857                         declaration = parse_declarator(specifiers,/*may_be_abstract=*/true);
2858
2859                         if(token.type == ':') {
2860                                 next_token();
2861                                 expression_t *size = parse_constant_expression();
2862
2863                                 type_t *type = make_bitfield_type(declaration->type, size);
2864                                 declaration->type = type;
2865                         }
2866                 }
2867                 record_declaration(declaration);
2868
2869                 if(token.type != ',')
2870                         break;
2871                 next_token();
2872         }
2873         expect_void(';');
2874 }
2875
2876 static void parse_compound_type_entries(void)
2877 {
2878         eat('{');
2879
2880         while(token.type != '}' && token.type != T_EOF) {
2881                 declaration_specifiers_t specifiers;
2882                 memset(&specifiers, 0, sizeof(specifiers));
2883                 parse_declaration_specifiers(&specifiers);
2884
2885                 parse_struct_declarators(&specifiers);
2886         }
2887         if(token.type == T_EOF) {
2888                 errorf(HERE, "EOF while parsing struct");
2889         }
2890         next_token();
2891 }
2892
2893 static type_t *parse_typename(void)
2894 {
2895         declaration_specifiers_t specifiers;
2896         memset(&specifiers, 0, sizeof(specifiers));
2897         parse_declaration_specifiers(&specifiers);
2898         if(specifiers.storage_class != STORAGE_CLASS_NONE) {
2899                 /* TODO: improve error message, user does probably not know what a
2900                  * storage class is...
2901                  */
2902                 errorf(HERE, "typename may not have a storage class");
2903         }
2904
2905         type_t *result = parse_abstract_declarator(specifiers.type);
2906
2907         return result;
2908 }
2909
2910
2911
2912
2913 typedef expression_t* (*parse_expression_function) (unsigned precedence);
2914 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
2915                                                           expression_t *left);
2916
2917 typedef struct expression_parser_function_t expression_parser_function_t;
2918 struct expression_parser_function_t {
2919         unsigned                         precedence;
2920         parse_expression_function        parser;
2921         unsigned                         infix_precedence;
2922         parse_expression_infix_function  infix_parser;
2923 };
2924
2925 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
2926
2927 /**
2928  * Creates a new invalid expression.
2929  */
2930 static expression_t *create_invalid_expression(void)
2931 {
2932         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
2933         expression->base.source_position = token.source_position;
2934         return expression;
2935 }
2936
2937 static expression_t *expected_expression_error(void)
2938 {
2939         errorf(HERE, "expected expression, got token '%K'", &token);
2940
2941         next_token();
2942
2943         return create_invalid_expression();
2944 }
2945
2946 /**
2947  * Parse a string constant.
2948  */
2949 static expression_t *parse_string_const(void)
2950 {
2951         expression_t *cnst  = allocate_expression_zero(EXPR_STRING_LITERAL);
2952         cnst->base.datatype = type_string;
2953         cnst->string.value  = parse_string_literals();
2954
2955         return cnst;
2956 }
2957
2958 /**
2959  * Parse a wide string constant.
2960  */
2961 static expression_t *parse_wide_string_const(void)
2962 {
2963         expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
2964         cnst->base.datatype      = type_wchar_t_ptr;
2965         cnst->wide_string.value  = token.v.wide_string; /* TODO concatenate */
2966         next_token();
2967         return cnst;
2968 }
2969
2970 /**
2971  * Parse an integer constant.
2972  */
2973 static expression_t *parse_int_const(void)
2974 {
2975         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
2976         cnst->base.datatype      = token.datatype;
2977         cnst->conste.v.int_value = token.v.intvalue;
2978
2979         next_token();
2980
2981         return cnst;
2982 }
2983
2984 /**
2985  * Parse a float constant.
2986  */
2987 static expression_t *parse_float_const(void)
2988 {
2989         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
2990         cnst->base.datatype        = token.datatype;
2991         cnst->conste.v.float_value = token.v.floatvalue;
2992
2993         next_token();
2994
2995         return cnst;
2996 }
2997
2998 static declaration_t *create_implicit_function(symbol_t *symbol,
2999                 const source_position_t source_position)
3000 {
3001         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
3002         ntype->function.return_type            = type_int;
3003         ntype->function.unspecified_parameters = true;
3004
3005         type_t *type = typehash_insert(ntype);
3006         if(type != ntype) {
3007                 free_type(ntype);
3008         }
3009
3010         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
3011
3012         declaration->storage_class   = STORAGE_CLASS_EXTERN;
3013         declaration->type            = type;
3014         declaration->symbol          = symbol;
3015         declaration->source_position = source_position;
3016         declaration->parent_context  = global_context;
3017
3018         context_t *old_context = context;
3019         set_context(global_context);
3020
3021         environment_push(declaration);
3022         /* prepend the declaration to the global declarations list */
3023         declaration->next     = context->declarations;
3024         context->declarations = declaration;
3025
3026         assert(context == global_context);
3027         set_context(old_context);
3028
3029         return declaration;
3030 }
3031
3032 /**
3033  * Creates a return_type (func)(argument_type) function type if not
3034  * already exists.
3035  *
3036  * @param return_type    the return type
3037  * @param argument_type  the argument type
3038  */
3039 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
3040 {
3041         function_parameter_t *parameter
3042                 = obstack_alloc(type_obst, sizeof(parameter[0]));
3043         memset(parameter, 0, sizeof(parameter[0]));
3044         parameter->type = argument_type;
3045
3046         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
3047         type->function.return_type = return_type;
3048         type->function.parameters  = parameter;
3049
3050         type_t *result = typehash_insert(type);
3051         if(result != type) {
3052                 free_type(type);
3053         }
3054
3055         return result;
3056 }
3057
3058 /**
3059  * Creates a function type for some function like builtins.
3060  *
3061  * @param symbol   the symbol describing the builtin
3062  */
3063 static type_t *get_builtin_symbol_type(symbol_t *symbol)
3064 {
3065         switch(symbol->ID) {
3066         case T___builtin_alloca:
3067                 return make_function_1_type(type_void_ptr, type_size_t);
3068         case T___builtin_nan:
3069                 return make_function_1_type(type_double, type_string);
3070         case T___builtin_nanf:
3071                 return make_function_1_type(type_float, type_string);
3072         case T___builtin_nand:
3073                 return make_function_1_type(type_long_double, type_string);
3074         case T___builtin_va_end:
3075                 return make_function_1_type(type_void, type_valist);
3076         default:
3077                 panic("not implemented builtin symbol found");
3078         }
3079 }
3080
3081 /**
3082  * Performs automatic type cast as described in § 6.3.2.1.
3083  *
3084  * @param orig_type  the original type
3085  */
3086 static type_t *automatic_type_conversion(type_t *orig_type)
3087 {
3088         if(orig_type == NULL)
3089                 return NULL;
3090
3091         type_t *type = skip_typeref(orig_type);
3092         if(is_type_array(type)) {
3093                 array_type_t *array_type   = &type->array;
3094                 type_t       *element_type = array_type->element_type;
3095                 unsigned      qualifiers   = array_type->type.qualifiers;
3096
3097                 return make_pointer_type(element_type, qualifiers);
3098         }
3099
3100         if(is_type_function(type)) {
3101                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3102         }
3103
3104         return orig_type;
3105 }
3106
3107 /**
3108  * reverts the automatic casts of array to pointer types and function
3109  * to function-pointer types as defined § 6.3.2.1
3110  */
3111 type_t *revert_automatic_type_conversion(const expression_t *expression)
3112 {
3113         if(expression->base.datatype == NULL)
3114                 return NULL;
3115
3116         switch(expression->kind) {
3117         case EXPR_REFERENCE: {
3118                 const reference_expression_t *ref = &expression->reference;
3119                 return ref->declaration->type;
3120         }
3121         case EXPR_SELECT: {
3122                 const select_expression_t *select = &expression->select;
3123                 return select->compound_entry->type;
3124         }
3125         case EXPR_UNARY_DEREFERENCE: {
3126                 expression_t   *value        = expression->unary.value;
3127                 type_t         *type         = skip_typeref(value->base.datatype);
3128                 pointer_type_t *pointer_type = &type->pointer;
3129
3130                 return pointer_type->points_to;
3131         }
3132         case EXPR_BUILTIN_SYMBOL: {
3133                 const builtin_symbol_expression_t *builtin
3134                         = &expression->builtin_symbol;
3135                 return get_builtin_symbol_type(builtin->symbol);
3136         }
3137         case EXPR_ARRAY_ACCESS: {
3138                 const array_access_expression_t *array_access
3139                         = &expression->array_access;
3140                 const expression_t *array_ref = array_access->array_ref;
3141                 type_t *type_left  = skip_typeref(array_ref->base.datatype);
3142                 assert(is_type_pointer(type_left));
3143                 pointer_type_t *pointer_type = &type_left->pointer;
3144                 return pointer_type->points_to;
3145         }
3146
3147         default:
3148                 break;
3149         }
3150
3151         return expression->base.datatype;
3152 }
3153
3154 static expression_t *parse_reference(void)
3155 {
3156         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
3157
3158         reference_expression_t *ref = &expression->reference;
3159         ref->symbol = token.v.symbol;
3160
3161         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
3162
3163         source_position_t source_position = token.source_position;
3164         next_token();
3165
3166         if(declaration == NULL) {
3167                 if (! strict_mode && token.type == '(') {
3168                         /* an implicitly defined function */
3169                         warningf(HERE, "implicit declaration of function '%Y'",
3170                                  ref->symbol);
3171
3172                         declaration = create_implicit_function(ref->symbol,
3173                                                                source_position);
3174                 } else {
3175                         errorf(HERE, "unknown symbol '%Y' found.", ref->symbol);
3176                         return expression;
3177                 }
3178         }
3179
3180         type_t *type         = declaration->type;
3181
3182         /* we always do the auto-type conversions; the & and sizeof parser contains
3183          * code to revert this! */
3184         type = automatic_type_conversion(type);
3185
3186         ref->declaration         = declaration;
3187         ref->expression.datatype = type;
3188
3189         return expression;
3190 }
3191
3192 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
3193 {
3194         (void) expression;
3195         (void) dest_type;
3196         /* TODO check if explicit cast is allowed and issue warnings/errors */
3197 }
3198
3199 static expression_t *parse_cast(void)
3200 {
3201         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
3202
3203         cast->base.source_position = token.source_position;
3204
3205         type_t *type  = parse_typename();
3206
3207         expect(')');
3208         expression_t *value = parse_sub_expression(20);
3209
3210         check_cast_allowed(value, type);
3211
3212         cast->base.datatype = type;
3213         cast->unary.value   = value;
3214
3215         return cast;
3216 }
3217
3218 static expression_t *parse_statement_expression(void)
3219 {
3220         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
3221
3222         statement_t *statement          = parse_compound_statement();
3223         expression->statement.statement = statement;
3224         if(statement == NULL) {
3225                 expect(')');
3226                 return NULL;
3227         }
3228
3229         assert(statement->kind == STATEMENT_COMPOUND);
3230         compound_statement_t *compound_statement = &statement->compound;
3231
3232         /* find last statement and use it's type */
3233         const statement_t *last_statement = NULL;
3234         const statement_t *iter           = compound_statement->statements;
3235         for( ; iter != NULL; iter = iter->base.next) {
3236                 last_statement = iter;
3237         }
3238
3239         if(last_statement->kind == STATEMENT_EXPRESSION) {
3240                 const expression_statement_t *expression_statement
3241                         = &last_statement->expression;
3242                 expression->base.datatype
3243                         = expression_statement->expression->base.datatype;
3244         } else {
3245                 expression->base.datatype = type_void;
3246         }
3247
3248         expect(')');
3249
3250         return expression;
3251 }
3252
3253 static expression_t *parse_brace_expression(void)
3254 {
3255         eat('(');
3256
3257         switch(token.type) {
3258         case '{':
3259                 /* gcc extension: a statement expression */
3260                 return parse_statement_expression();
3261
3262         TYPE_QUALIFIERS
3263         TYPE_SPECIFIERS
3264                 return parse_cast();
3265         case T_IDENTIFIER:
3266                 if(is_typedef_symbol(token.v.symbol)) {
3267                         return parse_cast();
3268                 }
3269         }
3270
3271         expression_t *result = parse_expression();
3272         expect(')');
3273
3274         return result;
3275 }
3276
3277 static expression_t *parse_function_keyword(void)
3278 {
3279         next_token();
3280         /* TODO */
3281
3282         if (current_function == NULL) {
3283                 errorf(HERE, "'__func__' used outside of a function");
3284         }
3285
3286         string_literal_expression_t *expression
3287                 = allocate_ast_zero(sizeof(expression[0]));
3288
3289         expression->expression.kind     = EXPR_FUNCTION;
3290         expression->expression.datatype = type_string;
3291         expression->value               = current_function->symbol->string;
3292
3293         return (expression_t*) expression;
3294 }
3295
3296 static expression_t *parse_pretty_function_keyword(void)
3297 {
3298         eat(T___PRETTY_FUNCTION__);
3299         /* TODO */
3300
3301         if (current_function == NULL) {
3302                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
3303         }
3304
3305         string_literal_expression_t *expression
3306                 = allocate_ast_zero(sizeof(expression[0]));
3307
3308         expression->expression.kind     = EXPR_PRETTY_FUNCTION;
3309         expression->expression.datatype = type_string;
3310         expression->value               = current_function->symbol->string;
3311
3312         return (expression_t*) expression;
3313 }
3314
3315 static designator_t *parse_designator(void)
3316 {
3317         designator_t *result = allocate_ast_zero(sizeof(result[0]));
3318
3319         if(token.type != T_IDENTIFIER) {
3320                 parse_error_expected("while parsing member designator",
3321                                      T_IDENTIFIER, 0);
3322                 eat_paren();
3323                 return NULL;
3324         }
3325         result->symbol = token.v.symbol;
3326         next_token();
3327
3328         designator_t *last_designator = result;
3329         while(true) {
3330                 if(token.type == '.') {
3331                         next_token();
3332                         if(token.type != T_IDENTIFIER) {
3333                                 parse_error_expected("while parsing member designator",
3334                                                      T_IDENTIFIER, 0);
3335                                 eat_paren();
3336                                 return NULL;
3337                         }
3338                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3339                         designator->symbol       = token.v.symbol;
3340                         next_token();
3341
3342                         last_designator->next = designator;
3343                         last_designator       = designator;
3344                         continue;
3345                 }
3346                 if(token.type == '[') {
3347                         next_token();
3348                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3349                         designator->array_access = parse_expression();
3350                         if(designator->array_access == NULL) {
3351                                 eat_paren();
3352                                 return NULL;
3353                         }
3354                         expect(']');
3355
3356                         last_designator->next = designator;
3357                         last_designator       = designator;
3358                         continue;
3359                 }
3360                 break;
3361         }
3362
3363         return result;
3364 }
3365
3366 static expression_t *parse_offsetof(void)
3367 {
3368         eat(T___builtin_offsetof);
3369
3370         expression_t *expression  = allocate_expression_zero(EXPR_OFFSETOF);
3371         expression->base.datatype = type_size_t;
3372
3373         expect('(');
3374         expression->offsetofe.type = parse_typename();
3375         expect(',');
3376         expression->offsetofe.designator = parse_designator();
3377         expect(')');
3378
3379         return expression;
3380 }
3381
3382 static expression_t *parse_va_start(void)
3383 {
3384         eat(T___builtin_va_start);
3385
3386         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
3387
3388         expect('(');
3389         expression->va_starte.ap = parse_assignment_expression();
3390         expect(',');
3391         expression_t *const expr = parse_assignment_expression();
3392         if (expr->kind == EXPR_REFERENCE) {
3393                 declaration_t *const decl = expr->reference.declaration;
3394                 if (decl->parent_context == &current_function->context &&
3395                     decl->next == NULL) {
3396                         expression->va_starte.parameter = decl;
3397                         expect(')');
3398                         return expression;
3399                 }
3400         }
3401         errorf(expr->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
3402
3403         return create_invalid_expression();
3404 }
3405
3406 static expression_t *parse_va_arg(void)
3407 {
3408         eat(T___builtin_va_arg);
3409
3410         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
3411
3412         expect('(');
3413         expression->va_arge.ap = parse_assignment_expression();
3414         expect(',');
3415         expression->base.datatype = parse_typename();
3416         expect(')');
3417
3418         return expression;
3419 }
3420
3421 static expression_t *parse_builtin_symbol(void)
3422 {
3423         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
3424
3425         symbol_t *symbol = token.v.symbol;
3426
3427         expression->builtin_symbol.symbol = symbol;
3428         next_token();
3429
3430         type_t *type = get_builtin_symbol_type(symbol);
3431         type = automatic_type_conversion(type);
3432
3433         expression->base.datatype = type;
3434         return expression;
3435 }
3436
3437 static expression_t *parse_builtin_constant(void)
3438 {
3439         eat(T___builtin_constant_p);
3440
3441         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
3442
3443         expect('(');
3444         expression->builtin_constant.value = parse_assignment_expression();
3445         expect(')');
3446         expression->base.datatype = type_int;
3447
3448         return expression;
3449 }
3450
3451 static expression_t *parse_builtin_prefetch(void)
3452 {
3453         eat(T___builtin_prefetch);
3454
3455         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
3456
3457         expect('(');
3458         expression->builtin_prefetch.adr = parse_assignment_expression();
3459         if (token.type == ',') {
3460                 next_token();
3461                 expression->builtin_prefetch.rw = parse_assignment_expression();
3462         }
3463         if (token.type == ',') {
3464                 next_token();
3465                 expression->builtin_prefetch.locality = parse_assignment_expression();
3466         }
3467         expect(')');
3468         expression->base.datatype = type_void;
3469
3470         return expression;
3471 }
3472
3473 static expression_t *parse_compare_builtin(void)
3474 {
3475         expression_t *expression;
3476
3477         switch(token.type) {
3478         case T___builtin_isgreater:
3479                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
3480                 break;
3481         case T___builtin_isgreaterequal:
3482                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
3483                 break;
3484         case T___builtin_isless:
3485                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
3486                 break;
3487         case T___builtin_islessequal:
3488                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
3489                 break;
3490         case T___builtin_islessgreater:
3491                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
3492                 break;
3493         case T___builtin_isunordered:
3494                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
3495                 break;
3496         default:
3497                 panic("invalid compare builtin found");
3498                 break;
3499         }
3500         next_token();
3501
3502         expect('(');
3503         expression->binary.left = parse_assignment_expression();
3504         expect(',');
3505         expression->binary.right = parse_assignment_expression();
3506         expect(')');
3507
3508         type_t *orig_type_left  = expression->binary.left->base.datatype;
3509         type_t *orig_type_right = expression->binary.right->base.datatype;
3510         if(orig_type_left == NULL || orig_type_right == NULL)
3511                 return expression;
3512
3513         type_t *type_left  = skip_typeref(orig_type_left);
3514         type_t *type_right = skip_typeref(orig_type_right);
3515         if(!is_type_floating(type_left) && !is_type_floating(type_right)) {
3516                 type_error_incompatible("invalid operands in comparison",
3517                                         token.source_position, type_left, type_right);
3518         } else {
3519                 semantic_comparison(&expression->binary);
3520         }
3521
3522         return expression;
3523 }
3524
3525 static expression_t *parse_builtin_expect(void)
3526 {
3527         eat(T___builtin_expect);
3528
3529         expression_t *expression
3530                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
3531
3532         expect('(');
3533         expression->binary.left = parse_assignment_expression();
3534         expect(',');
3535         expression->binary.right = parse_constant_expression();
3536         expect(')');
3537
3538         expression->base.datatype = expression->binary.left->base.datatype;
3539
3540         return expression;
3541 }
3542
3543 static expression_t *parse_assume(void) {
3544         eat(T_assume);
3545
3546         expression_t *expression
3547                 = allocate_expression_zero(EXPR_UNARY_ASSUME);
3548
3549         expect('(');
3550         expression->unary.value = parse_assignment_expression();
3551         expect(')');
3552
3553         expression->base.datatype = type_void;
3554         return expression;
3555 }
3556
3557 static expression_t *parse_alignof(void) {
3558         eat(T___alignof__);
3559
3560         expression_t *expression
3561                 = allocate_expression_zero(EXPR_ALIGNOF);
3562
3563         expect('(');
3564         expression->alignofe.type = parse_typename();
3565         expect(')');
3566
3567         expression->base.datatype = type_size_t;
3568         return expression;
3569 }
3570
3571 static expression_t *parse_primary_expression(void)
3572 {
3573         switch(token.type) {
3574         case T_INTEGER:
3575                 return parse_int_const();
3576         case T_FLOATINGPOINT:
3577                 return parse_float_const();
3578         case T_STRING_LITERAL:
3579                 return parse_string_const();
3580         case T_WIDE_STRING_LITERAL:
3581                 return parse_wide_string_const();
3582         case T_IDENTIFIER:
3583                 return parse_reference();
3584         case T___FUNCTION__:
3585         case T___func__:
3586                 return parse_function_keyword();
3587         case T___PRETTY_FUNCTION__:
3588                 return parse_pretty_function_keyword();
3589         case T___builtin_offsetof:
3590                 return parse_offsetof();
3591         case T___builtin_va_start:
3592                 return parse_va_start();
3593         case T___builtin_va_arg:
3594                 return parse_va_arg();
3595         case T___builtin_expect:
3596                 return parse_builtin_expect();
3597         case T___builtin_nanf:
3598         case T___builtin_alloca:
3599         case T___builtin_va_end:
3600                 return parse_builtin_symbol();
3601         case T___builtin_isgreater:
3602         case T___builtin_isgreaterequal:
3603         case T___builtin_isless:
3604         case T___builtin_islessequal:
3605         case T___builtin_islessgreater:
3606         case T___builtin_isunordered:
3607                 return parse_compare_builtin();
3608         case T___builtin_constant_p:
3609                 return parse_builtin_constant();
3610         case T___builtin_prefetch:
3611                 return parse_builtin_prefetch();
3612         case T___alignof__:
3613                 return parse_alignof();
3614         case T_assume:
3615                 return parse_assume();
3616
3617         case '(':
3618                 return parse_brace_expression();
3619         }
3620
3621         errorf(HERE, "unexpected token '%K'", &token);
3622         eat_statement();
3623
3624         return create_invalid_expression();
3625 }
3626
3627 /**
3628  * Check if the expression has the character type and issue a warning then.
3629  */
3630 static void check_for_char_index_type(const expression_t *expression) {
3631         type_t *type      = expression->base.datatype;
3632         type_t *base_type = skip_typeref(type);
3633
3634         if (base_type->base.kind == TYPE_ATOMIC) {
3635                 if (base_type->atomic.akind == ATOMIC_TYPE_CHAR) {
3636                         warningf(expression->base.source_position,
3637                                 "array subscript has type '%T'", type);
3638                 }
3639         }
3640 }
3641
3642 static expression_t *parse_array_expression(unsigned precedence,
3643                                             expression_t *left)
3644 {
3645         (void) precedence;
3646
3647         eat('[');
3648
3649         expression_t *inside = parse_expression();
3650
3651         array_access_expression_t *array_access
3652                 = allocate_ast_zero(sizeof(array_access[0]));
3653
3654         array_access->expression.kind = EXPR_ARRAY_ACCESS;
3655
3656         type_t *type_left   = left->base.datatype;
3657         type_t *type_inside = inside->base.datatype;
3658         type_t *return_type = NULL;
3659
3660         if(type_left != NULL && type_inside != NULL) {
3661                 type_left   = skip_typeref(type_left);
3662                 type_inside = skip_typeref(type_inside);
3663
3664                 if(is_type_pointer(type_left)) {
3665                         pointer_type_t *pointer = &type_left->pointer;
3666                         return_type             = pointer->points_to;
3667                         array_access->array_ref = left;
3668                         array_access->index     = inside;
3669                         check_for_char_index_type(inside);
3670                 } else if(is_type_pointer(type_inside)) {
3671                         pointer_type_t *pointer = &type_inside->pointer;
3672                         return_type             = pointer->points_to;
3673                         array_access->array_ref = inside;
3674                         array_access->index     = left;
3675                         array_access->flipped   = true;
3676                         check_for_char_index_type(left);
3677                 } else {
3678                         errorf(HERE, "array access on object with non-pointer types '%T', '%T'", type_left, type_inside);
3679                 }
3680         } else {
3681                 array_access->array_ref = left;
3682                 array_access->index     = inside;
3683         }
3684
3685         if(token.type != ']') {
3686                 parse_error_expected("Problem while parsing array access", ']', 0);
3687                 return (expression_t*) array_access;
3688         }
3689         next_token();
3690
3691         return_type = automatic_type_conversion(return_type);
3692         array_access->expression.datatype = return_type;
3693
3694         return (expression_t*) array_access;
3695 }
3696
3697 static expression_t *parse_sizeof(unsigned precedence)
3698 {
3699         eat(T_sizeof);
3700
3701         sizeof_expression_t *sizeof_expression
3702                 = allocate_ast_zero(sizeof(sizeof_expression[0]));
3703         sizeof_expression->expression.kind     = EXPR_SIZEOF;
3704         sizeof_expression->expression.datatype = type_size_t;
3705
3706         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
3707                 next_token();
3708                 sizeof_expression->type = parse_typename();
3709                 expect(')');
3710         } else {
3711                 expression_t *expression  = parse_sub_expression(precedence);
3712                 expression->base.datatype = revert_automatic_type_conversion(expression);
3713
3714                 sizeof_expression->type            = expression->base.datatype;
3715                 sizeof_expression->size_expression = expression;
3716         }
3717
3718         return (expression_t*) sizeof_expression;
3719 }
3720
3721 static expression_t *parse_select_expression(unsigned precedence,
3722                                              expression_t *compound)
3723 {
3724         (void) precedence;
3725         assert(token.type == '.' || token.type == T_MINUSGREATER);
3726
3727         bool is_pointer = (token.type == T_MINUSGREATER);
3728         next_token();
3729
3730         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
3731         select->select.compound = compound;
3732
3733         if(token.type != T_IDENTIFIER) {
3734                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
3735                 return select;
3736         }
3737         symbol_t *symbol      = token.v.symbol;
3738         select->select.symbol = symbol;
3739         next_token();
3740
3741         type_t *orig_type = compound->base.datatype;
3742         if(orig_type == NULL)
3743                 return create_invalid_expression();
3744
3745         type_t *type = skip_typeref(orig_type);
3746
3747         type_t *type_left = type;
3748         if(is_pointer) {
3749                 if(type->kind != TYPE_POINTER) {
3750                         errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
3751                         return create_invalid_expression();
3752                 }
3753                 pointer_type_t *pointer_type = &type->pointer;
3754                 type_left                    = pointer_type->points_to;
3755         }
3756         type_left = skip_typeref(type_left);
3757
3758         if(type_left->kind != TYPE_COMPOUND_STRUCT
3759                         && type_left->kind != TYPE_COMPOUND_UNION) {
3760                 errorf(HERE, "request for member '%Y' in something not a struct or "
3761                        "union, but '%T'", symbol, type_left);
3762                 return create_invalid_expression();
3763         }
3764
3765         compound_type_t *compound_type = &type_left->compound;
3766         declaration_t   *declaration   = compound_type->declaration;
3767
3768         if(!declaration->init.is_defined) {
3769                 errorf(HERE, "request for member '%Y' of incomplete type '%T'",
3770                        symbol, type_left);
3771                 return create_invalid_expression();
3772         }
3773
3774         declaration_t *iter = declaration->context.declarations;
3775         for( ; iter != NULL; iter = iter->next) {
3776                 if(iter->symbol == symbol) {
3777                         break;
3778                 }
3779         }
3780         if(iter == NULL) {
3781                 errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
3782                 return create_invalid_expression();
3783         }
3784
3785         /* we always do the auto-type conversions; the & and sizeof parser contains
3786          * code to revert this! */
3787         type_t *expression_type = automatic_type_conversion(iter->type);
3788
3789         select->select.compound_entry = iter;
3790         select->base.datatype         = expression_type;
3791
3792         if(expression_type->kind == TYPE_BITFIELD) {
3793                 expression_t *extract
3794                         = allocate_expression_zero(EXPR_UNARY_BITFIELD_EXTRACT);
3795                 extract->unary.value   = select;
3796                 extract->base.datatype = expression_type->bitfield.base;
3797
3798                 return extract;
3799         }
3800
3801         return select;
3802 }
3803
3804 /**
3805  * Parse a call expression, ie. expression '( ... )'.
3806  *
3807  * @param expression  the function address
3808  */
3809 static expression_t *parse_call_expression(unsigned precedence,
3810                                            expression_t *expression)
3811 {
3812         (void) precedence;
3813         expression_t *result = allocate_expression_zero(EXPR_CALL);
3814
3815         call_expression_t *call = &result->call;
3816         call->function          = expression;
3817
3818         function_type_t *function_type = NULL;
3819         type_t          *orig_type     = expression->base.datatype;
3820         if(orig_type != NULL) {
3821                 type_t *type  = skip_typeref(orig_type);
3822
3823                 if(is_type_pointer(type)) {
3824                         pointer_type_t *pointer_type = &type->pointer;
3825
3826                         type = skip_typeref(pointer_type->points_to);
3827
3828                         if (is_type_function(type)) {
3829                                 function_type             = &type->function;
3830                                 call->expression.datatype = function_type->return_type;
3831                         }
3832                 }
3833                 if(function_type == NULL) {
3834                         errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
3835
3836                         function_type             = NULL;
3837                         call->expression.datatype = NULL;
3838                 }
3839         }
3840
3841         /* parse arguments */
3842         eat('(');
3843
3844         if(token.type != ')') {
3845                 call_argument_t *last_argument = NULL;
3846
3847                 while(true) {
3848                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
3849
3850                         argument->expression = parse_assignment_expression();
3851                         if(last_argument == NULL) {
3852                                 call->arguments = argument;
3853                         } else {
3854                                 last_argument->next = argument;
3855                         }
3856                         last_argument = argument;
3857
3858                         if(token.type != ',')
3859                                 break;
3860                         next_token();
3861                 }
3862         }
3863         expect(')');
3864
3865         if(function_type != NULL) {
3866                 function_parameter_t *parameter = function_type->parameters;
3867                 call_argument_t      *argument  = call->arguments;
3868                 for( ; parameter != NULL && argument != NULL;
3869                                 parameter = parameter->next, argument = argument->next) {
3870                         type_t *expected_type = parameter->type;
3871                         /* TODO report context in error messages */
3872                         argument->expression = create_implicit_cast(argument->expression,
3873                                                                     expected_type);
3874                 }
3875                 /* too few parameters */
3876                 if(parameter != NULL) {
3877                         errorf(HERE, "too few arguments to function '%E'", expression);
3878                 } else if(argument != NULL) {
3879                         /* too many parameters */
3880                         if(!function_type->variadic
3881                                         && !function_type->unspecified_parameters) {
3882                                 errorf(HERE, "too many arguments to function '%E'", expression);
3883                         } else {
3884                                 /* do default promotion */
3885                                 for( ; argument != NULL; argument = argument->next) {
3886                                         type_t *type = argument->expression->base.datatype;
3887
3888                                         if(type == NULL)
3889                                                 continue;
3890
3891                                         type = skip_typeref(type);
3892                                         if(is_type_integer(type)) {
3893                                                 type = promote_integer(type);
3894                                         } else if(type == type_float) {
3895                                                 type = type_double;
3896                                         }
3897
3898                                         argument->expression
3899                                                 = create_implicit_cast(argument->expression, type);
3900                                 }
3901
3902                                 check_format(&result->call);
3903                         }
3904                 } else {
3905                         check_format(&result->call);
3906                 }
3907         }
3908
3909         return result;
3910 }
3911
3912 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
3913
3914 static bool same_compound_type(const type_t *type1, const type_t *type2)
3915 {
3916         if(!is_type_compound(type1))
3917                 return false;
3918         if(type1->kind != type2->kind)
3919                 return false;
3920
3921         const compound_type_t *compound1 = &type1->compound;
3922         const compound_type_t *compound2 = &type2->compound;
3923
3924         return compound1->declaration == compound2->declaration;
3925 }
3926
3927 /**
3928  * Parse a conditional expression, ie. 'expression ? ... : ...'.
3929  *
3930  * @param expression  the conditional expression
3931  */
3932 static expression_t *parse_conditional_expression(unsigned precedence,
3933                                                   expression_t *expression)
3934 {
3935         eat('?');
3936
3937         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
3938
3939         conditional_expression_t *conditional = &result->conditional;
3940         conditional->condition = expression;
3941
3942         /* 6.5.15.2 */
3943         type_t *condition_type_orig = expression->base.datatype;
3944         if(condition_type_orig != NULL) {
3945                 type_t *condition_type = skip_typeref(condition_type_orig);
3946                 if(condition_type != NULL && !is_type_scalar(condition_type)) {
3947                         type_error("expected a scalar type in conditional condition",
3948                                    expression->base.source_position, condition_type_orig);
3949                 }
3950         }
3951
3952         expression_t *true_expression = parse_expression();
3953         expect(':');
3954         expression_t *false_expression = parse_sub_expression(precedence);
3955
3956         conditional->true_expression  = true_expression;
3957         conditional->false_expression = false_expression;
3958
3959         type_t *orig_true_type  = true_expression->base.datatype;
3960         type_t *orig_false_type = false_expression->base.datatype;
3961         if(orig_true_type == NULL || orig_false_type == NULL)
3962                 return result;
3963
3964         type_t *true_type  = skip_typeref(orig_true_type);
3965         type_t *false_type = skip_typeref(orig_false_type);
3966
3967         /* 6.5.15.3 */
3968         type_t *result_type = NULL;
3969         if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
3970                 result_type = semantic_arithmetic(true_type, false_type);
3971
3972                 true_expression  = create_implicit_cast(true_expression, result_type);
3973                 false_expression = create_implicit_cast(false_expression, result_type);
3974
3975                 conditional->true_expression     = true_expression;
3976                 conditional->false_expression    = false_expression;
3977                 conditional->expression.datatype = result_type;
3978         } else if (same_compound_type(true_type, false_type)
3979                         || (is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
3980                                 is_type_atomic(false_type, ATOMIC_TYPE_VOID))) {
3981                 /* just take 1 of the 2 types */
3982                 result_type = true_type;
3983         } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
3984                         && pointers_compatible(true_type, false_type)) {
3985                 /* ok */
3986                 result_type = true_type;
3987         } else {
3988                 /* TODO */
3989                 type_error_incompatible("while parsing conditional",
3990                                         expression->base.source_position, true_type,
3991                                         false_type);
3992         }
3993
3994         conditional->expression.datatype = result_type;
3995         return result;
3996 }
3997
3998 /**
3999  * Parse an extension expression.
4000  */
4001 static expression_t *parse_extension(unsigned precedence)
4002 {
4003         eat(T___extension__);
4004
4005         /* TODO enable extensions */
4006         expression_t *expression = parse_sub_expression(precedence);
4007         /* TODO disable extensions */
4008         return expression;
4009 }
4010
4011 static expression_t *parse_builtin_classify_type(const unsigned precedence)
4012 {
4013         eat(T___builtin_classify_type);
4014
4015         expression_t *result  = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
4016         result->base.datatype = type_int;
4017
4018         expect('(');
4019         expression_t *expression = parse_sub_expression(precedence);
4020         expect(')');
4021         result->classify_type.type_expression = expression;
4022
4023         return result;
4024 }
4025
4026 static void semantic_incdec(unary_expression_t *expression)
4027 {
4028         type_t *orig_type = expression->value->base.datatype;
4029         if(orig_type == NULL)
4030                 return;
4031
4032         type_t *type = skip_typeref(orig_type);
4033         if(!is_type_arithmetic(type) && type->kind != TYPE_POINTER) {
4034                 /* TODO: improve error message */
4035                 errorf(HERE, "operation needs an arithmetic or pointer type");
4036                 return;
4037         }
4038
4039         expression->expression.datatype = orig_type;
4040 }
4041
4042 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
4043 {
4044         type_t *orig_type = expression->value->base.datatype;
4045         if(orig_type == NULL)
4046                 return;
4047
4048         type_t *type = skip_typeref(orig_type);
4049         if(!is_type_arithmetic(type)) {
4050                 /* TODO: improve error message */
4051                 errorf(HERE, "operation needs an arithmetic type");
4052                 return;
4053         }
4054
4055         expression->expression.datatype = orig_type;
4056 }
4057
4058 static void semantic_unexpr_scalar(unary_expression_t *expression)
4059 {
4060         type_t *orig_type = expression->value->base.datatype;
4061         if(orig_type == NULL)
4062                 return;
4063
4064         type_t *type = skip_typeref(orig_type);
4065         if (!is_type_scalar(type)) {
4066                 errorf(HERE, "operand of ! must be of scalar type");
4067                 return;
4068         }
4069
4070         expression->expression.datatype = orig_type;
4071 }
4072
4073 static void semantic_unexpr_integer(unary_expression_t *expression)
4074 {
4075         type_t *orig_type = expression->value->base.datatype;
4076         if(orig_type == NULL)
4077                 return;
4078
4079         type_t *type = skip_typeref(orig_type);
4080         if (!is_type_integer(type)) {
4081                 errorf(HERE, "operand of ~ must be of integer type");
4082                 return;
4083         }
4084
4085         expression->expression.datatype = orig_type;
4086 }
4087
4088 static void semantic_dereference(unary_expression_t *expression)
4089 {
4090         type_t *orig_type = expression->value->base.datatype;
4091         if(orig_type == NULL)
4092                 return;
4093
4094         type_t *type = skip_typeref(orig_type);
4095         if(!is_type_pointer(type)) {
4096                 errorf(HERE, "Unary '*' needs pointer or arrray type, but type '%T' given", orig_type);
4097                 return;
4098         }
4099
4100         pointer_type_t *pointer_type = &type->pointer;
4101         type_t         *result_type  = pointer_type->points_to;
4102
4103         result_type = automatic_type_conversion(result_type);
4104         expression->expression.datatype = result_type;
4105 }
4106
4107 /**
4108  * Check the semantic of the address taken expression.
4109  */
4110 static void semantic_take_addr(unary_expression_t *expression)
4111 {
4112         expression_t *value  = expression->value;
4113         value->base.datatype = revert_automatic_type_conversion(value);
4114
4115         type_t *orig_type = value->base.datatype;
4116         if(orig_type == NULL)
4117                 return;
4118
4119         if(value->kind == EXPR_REFERENCE) {
4120                 reference_expression_t *reference   = (reference_expression_t*) value;
4121                 declaration_t          *declaration = reference->declaration;
4122                 if(declaration != NULL) {
4123                         if (declaration->storage_class == STORAGE_CLASS_REGISTER) {
4124                                 errorf(expression->expression.source_position,
4125                                         "address of register variable '%Y' requested",
4126                                         declaration->symbol);
4127                         }
4128                         declaration->address_taken = 1;
4129                 }
4130         }
4131
4132         expression->expression.datatype = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
4133 }
4134
4135 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
4136 static expression_t *parse_##unexpression_type(unsigned precedence)            \
4137 {                                                                              \
4138         eat(token_type);                                                           \
4139                                                                                    \
4140         expression_t *unary_expression                                             \
4141                 = allocate_expression_zero(unexpression_type);                         \
4142         unary_expression->base.source_position = HERE;                             \
4143         unary_expression->unary.value = parse_sub_expression(precedence);          \
4144                                                                                    \
4145         sfunc(&unary_expression->unary);                                           \
4146                                                                                    \
4147         return unary_expression;                                                   \
4148 }
4149
4150 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
4151                                semantic_unexpr_arithmetic)
4152 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
4153                                semantic_unexpr_arithmetic)
4154 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
4155                                semantic_unexpr_scalar)
4156 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
4157                                semantic_dereference)
4158 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
4159                                semantic_take_addr)
4160 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
4161                                semantic_unexpr_integer)
4162 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
4163                                semantic_incdec)
4164 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
4165                                semantic_incdec)
4166
4167 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
4168                                                sfunc)                         \
4169 static expression_t *parse_##unexpression_type(unsigned precedence,           \
4170                                                expression_t *left)            \
4171 {                                                                             \
4172         (void) precedence;                                                        \
4173         eat(token_type);                                                          \
4174                                                                               \
4175         expression_t *unary_expression                                            \
4176                 = allocate_expression_zero(unexpression_type);                        \
4177         unary_expression->unary.value = left;                                     \
4178                                                                                   \
4179         sfunc(&unary_expression->unary);                                          \
4180                                                                               \
4181         return unary_expression;                                                  \
4182 }
4183
4184 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
4185                                        EXPR_UNARY_POSTFIX_INCREMENT,
4186                                        semantic_incdec)
4187 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
4188                                        EXPR_UNARY_POSTFIX_DECREMENT,
4189                                        semantic_incdec)
4190
4191 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
4192 {
4193         /* TODO: handle complex + imaginary types */
4194
4195         /* § 6.3.1.8 Usual arithmetic conversions */
4196         if(type_left == type_long_double || type_right == type_long_double) {
4197                 return type_long_double;
4198         } else if(type_left == type_double || type_right == type_double) {
4199                 return type_double;
4200         } else if(type_left == type_float || type_right == type_float) {
4201                 return type_float;
4202         }
4203
4204         type_right = promote_integer(type_right);
4205         type_left  = promote_integer(type_left);
4206
4207         if(type_left == type_right)
4208                 return type_left;
4209
4210         bool signed_left  = is_type_signed(type_left);
4211         bool signed_right = is_type_signed(type_right);
4212         int  rank_left    = get_rank(type_left);
4213         int  rank_right   = get_rank(type_right);
4214         if(rank_left < rank_right) {
4215                 if(signed_left == signed_right || !signed_right) {
4216                         return type_right;
4217                 } else {
4218                         return type_left;
4219                 }
4220         } else {
4221                 if(signed_left == signed_right || !signed_left) {
4222                         return type_left;
4223                 } else {
4224                         return type_right;
4225                 }
4226         }
4227 }
4228
4229 /**
4230  * Check the semantic restrictions for a binary expression.
4231  */
4232 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
4233 {
4234         expression_t *left       = expression->left;
4235         expression_t *right      = expression->right;
4236         type_t       *orig_type_left  = left->base.datatype;
4237         type_t       *orig_type_right = right->base.datatype;
4238
4239         if(orig_type_left == NULL || orig_type_right == NULL)
4240                 return;
4241
4242         type_t *type_left  = skip_typeref(orig_type_left);
4243         type_t *type_right = skip_typeref(orig_type_right);
4244
4245         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4246                 /* TODO: improve error message */
4247                 errorf(HERE, "operation needs arithmetic types");
4248                 return;
4249         }
4250
4251         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4252         expression->left  = create_implicit_cast(left, arithmetic_type);
4253         expression->right = create_implicit_cast(right, arithmetic_type);
4254         expression->expression.datatype = arithmetic_type;
4255 }
4256
4257 static void semantic_shift_op(binary_expression_t *expression)
4258 {
4259         expression_t *left       = expression->left;
4260         expression_t *right      = expression->right;
4261         type_t       *orig_type_left  = left->base.datatype;
4262         type_t       *orig_type_right = right->base.datatype;
4263
4264         if(orig_type_left == NULL || orig_type_right == NULL)
4265                 return;
4266
4267         type_t *type_left  = skip_typeref(orig_type_left);
4268         type_t *type_right = skip_typeref(orig_type_right);
4269
4270         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
4271                 /* TODO: improve error message */
4272                 errorf(HERE, "operation needs integer types");
4273                 return;
4274         }
4275
4276         type_left  = promote_integer(type_left);
4277         type_right = promote_integer(type_right);
4278
4279         expression->left  = create_implicit_cast(left, type_left);
4280         expression->right = create_implicit_cast(right, type_right);
4281         expression->expression.datatype = type_left;
4282 }
4283
4284 static void semantic_add(binary_expression_t *expression)
4285 {
4286         expression_t *left            = expression->left;
4287         expression_t *right           = expression->right;
4288         type_t       *orig_type_left  = left->base.datatype;
4289         type_t       *orig_type_right = right->base.datatype;
4290
4291         if(orig_type_left == NULL || orig_type_right == NULL)
4292                 return;
4293
4294         type_t *type_left  = skip_typeref(orig_type_left);
4295         type_t *type_right = skip_typeref(orig_type_right);
4296
4297         /* § 5.6.5 */
4298         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4299                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4300                 expression->left  = create_implicit_cast(left, arithmetic_type);
4301                 expression->right = create_implicit_cast(right, arithmetic_type);
4302                 expression->expression.datatype = arithmetic_type;
4303                 return;
4304         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4305                 expression->expression.datatype = type_left;
4306         } else if(is_type_pointer(type_right) && is_type_integer(type_left)) {
4307                 expression->expression.datatype = type_right;
4308         } else {
4309                 errorf(HERE, "invalid operands to binary + ('%T', '%T')", orig_type_left, orig_type_right);
4310         }
4311 }
4312
4313 static void semantic_sub(binary_expression_t *expression)
4314 {
4315         expression_t *left            = expression->left;
4316         expression_t *right           = expression->right;
4317         type_t       *orig_type_left  = left->base.datatype;
4318         type_t       *orig_type_right = right->base.datatype;
4319
4320         if(orig_type_left == NULL || orig_type_right == NULL)
4321                 return;
4322
4323         type_t       *type_left       = skip_typeref(orig_type_left);
4324         type_t       *type_right      = skip_typeref(orig_type_right);
4325
4326         /* § 5.6.5 */
4327         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4328                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4329                 expression->left  = create_implicit_cast(left, arithmetic_type);
4330                 expression->right = create_implicit_cast(right, arithmetic_type);
4331                 expression->expression.datatype = arithmetic_type;
4332                 return;
4333         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4334                 expression->expression.datatype = type_left;
4335         } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
4336                 if(!pointers_compatible(type_left, type_right)) {
4337                         errorf(HERE, "pointers to incompatible objects to binary - ('%T', '%T')", orig_type_left, orig_type_right);
4338                 } else {
4339                         expression->expression.datatype = type_ptrdiff_t;
4340                 }
4341         } else {
4342                 errorf(HERE, "invalid operands to binary - ('%T', '%T')", orig_type_left, orig_type_right);
4343         }
4344 }
4345
4346 static void semantic_comparison(binary_expression_t *expression)
4347 {
4348         expression_t *left            = expression->left;
4349         expression_t *right           = expression->right;
4350         type_t       *orig_type_left  = left->base.datatype;
4351         type_t       *orig_type_right = right->base.datatype;
4352
4353         if(orig_type_left == NULL || orig_type_right == NULL)
4354                 return;
4355
4356         type_t *type_left  = skip_typeref(orig_type_left);
4357         type_t *type_right = skip_typeref(orig_type_right);
4358
4359         /* TODO non-arithmetic types */
4360         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4361                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4362                 expression->left  = create_implicit_cast(left, arithmetic_type);
4363                 expression->right = create_implicit_cast(right, arithmetic_type);
4364                 expression->expression.datatype = arithmetic_type;
4365         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
4366                 /* TODO check compatibility */
4367         } else if (is_type_pointer(type_left)) {
4368                 expression->right = create_implicit_cast(right, type_left);
4369         } else if (is_type_pointer(type_right)) {
4370                 expression->left = create_implicit_cast(left, type_right);
4371         } else {
4372                 type_error_incompatible("invalid operands in comparison",
4373                                         token.source_position, type_left, type_right);
4374         }
4375         expression->expression.datatype = type_int;
4376 }
4377
4378 static void semantic_arithmetic_assign(binary_expression_t *expression)
4379 {
4380         expression_t *left            = expression->left;
4381         expression_t *right           = expression->right;
4382         type_t       *orig_type_left  = left->base.datatype;
4383         type_t       *orig_type_right = right->base.datatype;
4384
4385         if(orig_type_left == NULL || orig_type_right == NULL)
4386                 return;
4387
4388         type_t *type_left  = skip_typeref(orig_type_left);
4389         type_t *type_right = skip_typeref(orig_type_right);
4390
4391         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4392                 /* TODO: improve error message */
4393                 errorf(HERE, "operation needs arithmetic types");
4394                 return;
4395         }
4396
4397         /* combined instructions are tricky. We can't create an implicit cast on
4398          * the left side, because we need the uncasted form for the store.
4399          * The ast2firm pass has to know that left_type must be right_type
4400          * for the arithmetic operation and create a cast by itself */
4401         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4402         expression->right       = create_implicit_cast(right, arithmetic_type);
4403         expression->expression.datatype = type_left;
4404 }
4405
4406 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
4407 {
4408         expression_t *left            = expression->left;
4409         expression_t *right           = expression->right;
4410         type_t       *orig_type_left  = left->base.datatype;
4411         type_t       *orig_type_right = right->base.datatype;
4412
4413         if(orig_type_left == NULL || orig_type_right == NULL)
4414                 return;
4415
4416         type_t *type_left  = skip_typeref(orig_type_left);
4417         type_t *type_right = skip_typeref(orig_type_right);
4418
4419         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4420                 /* combined instructions are tricky. We can't create an implicit cast on
4421                  * the left side, because we need the uncasted form for the store.
4422                  * The ast2firm pass has to know that left_type must be right_type
4423                  * for the arithmetic operation and create a cast by itself */
4424                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
4425                 expression->right = create_implicit_cast(right, arithmetic_type);
4426                 expression->expression.datatype = type_left;
4427         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
4428                 expression->expression.datatype = type_left;
4429         } else {
4430                 errorf(HERE, "incompatible types '%T' and '%T' in assignment", orig_type_left, orig_type_right);
4431                 return;
4432         }
4433 }
4434
4435 /**
4436  * Check the semantic restrictions of a logical expression.
4437  */
4438 static void semantic_logical_op(binary_expression_t *expression)
4439 {
4440         expression_t *left            = expression->left;
4441         expression_t *right           = expression->right;
4442         type_t       *orig_type_left  = left->base.datatype;
4443         type_t       *orig_type_right = right->base.datatype;
4444
4445         if(orig_type_left == NULL || orig_type_right == NULL)
4446                 return;
4447
4448         type_t *type_left  = skip_typeref(orig_type_left);
4449         type_t *type_right = skip_typeref(orig_type_right);
4450
4451         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
4452                 /* TODO: improve error message */
4453                 errorf(HERE, "operation needs scalar types");
4454                 return;
4455         }
4456
4457         expression->expression.datatype = type_int;
4458 }
4459
4460 /**
4461  * Checks if a compound type has constant fields.
4462  */
4463 static bool has_const_fields(const compound_type_t *type)
4464 {
4465         const context_t     *context = &type->declaration->context;
4466         const declaration_t *declaration = context->declarations;
4467
4468         for (; declaration != NULL; declaration = declaration->next) {
4469                 if (declaration->namespc != NAMESPACE_NORMAL)
4470                         continue;
4471
4472                 const type_t *decl_type = skip_typeref(declaration->type);
4473                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
4474                         return true;
4475         }
4476         /* TODO */
4477         return false;
4478 }
4479
4480 /**
4481  * Check the semantic restrictions of a binary assign expression.
4482  */
4483 static void semantic_binexpr_assign(binary_expression_t *expression)
4484 {
4485         expression_t *left           = expression->left;
4486         type_t       *orig_type_left = left->base.datatype;
4487
4488         if(orig_type_left == NULL)
4489                 return;
4490
4491         type_t *type_left = revert_automatic_type_conversion(left);
4492         type_left         = skip_typeref(orig_type_left);
4493
4494         /* must be a modifiable lvalue */
4495         if (is_type_array(type_left)) {
4496                 errorf(HERE, "cannot assign to arrays ('%E')", left);
4497                 return;
4498         }
4499         if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
4500                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
4501                        orig_type_left);
4502                 return;
4503         }
4504         if(is_type_incomplete(type_left)) {
4505                 errorf(HERE,
4506                        "left-hand side of assignment '%E' has incomplete type '%T'",
4507                        left, orig_type_left);
4508                 return;
4509         }
4510         if(is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
4511                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
4512                        left, orig_type_left);
4513                 return;
4514         }
4515
4516         semantic_assign(orig_type_left, &expression->right, "assignment");
4517
4518         expression->expression.datatype = orig_type_left;
4519 }
4520
4521 static void semantic_comma(binary_expression_t *expression)
4522 {
4523         expression->expression.datatype = expression->right->base.datatype;
4524 }
4525
4526 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
4527 static expression_t *parse_##binexpression_type(unsigned precedence,      \
4528                                                 expression_t *left)       \
4529 {                                                                         \
4530         eat(token_type);                                                      \
4531                                                                           \
4532         expression_t *right = parse_sub_expression(precedence + lr);          \
4533                                                                           \
4534         expression_t *binexpr = allocate_expression_zero(binexpression_type); \
4535         binexpr->binary.left  = left;                                         \
4536         binexpr->binary.right = right;                                        \
4537         sfunc(&binexpr->binary);                                              \
4538                                                                           \
4539         return binexpr;                                                       \
4540 }
4541
4542 CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
4543 CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
4544 CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
4545 CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
4546 CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
4547 CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
4548 CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
4549 CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
4550 CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
4551
4552 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
4553                       semantic_comparison, 1)
4554 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
4555                       semantic_comparison, 1)
4556 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
4557                       semantic_comparison, 1)
4558 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
4559                       semantic_comparison, 1)
4560
4561 CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
4562                       semantic_binexpr_arithmetic, 1)
4563 CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
4564                       semantic_binexpr_arithmetic, 1)
4565 CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
4566                       semantic_binexpr_arithmetic, 1)
4567 CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
4568                       semantic_logical_op, 1)
4569 CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
4570                       semantic_logical_op, 1)
4571 CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
4572                       semantic_shift_op, 1)
4573 CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
4574                       semantic_shift_op, 1)
4575 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
4576                       semantic_arithmetic_addsubb_assign, 0)
4577 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
4578                       semantic_arithmetic_addsubb_assign, 0)
4579 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
4580                       semantic_arithmetic_assign, 0)
4581 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
4582                       semantic_arithmetic_assign, 0)
4583 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
4584                       semantic_arithmetic_assign, 0)
4585 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
4586                       semantic_arithmetic_assign, 0)
4587 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4588                       semantic_arithmetic_assign, 0)
4589 CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
4590                       semantic_arithmetic_assign, 0)
4591 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
4592                       semantic_arithmetic_assign, 0)
4593 CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
4594                       semantic_arithmetic_assign, 0)
4595
4596 static expression_t *parse_sub_expression(unsigned precedence)
4597 {
4598         if(token.type < 0) {
4599                 return expected_expression_error();
4600         }
4601
4602         expression_parser_function_t *parser
4603                 = &expression_parsers[token.type];
4604         source_position_t             source_position = token.source_position;
4605         expression_t                 *left;
4606
4607         if(parser->parser != NULL) {
4608                 left = parser->parser(parser->precedence);
4609         } else {
4610                 left = parse_primary_expression();
4611         }
4612         assert(left != NULL);
4613         left->base.source_position = source_position;
4614
4615         while(true) {
4616                 if(token.type < 0) {
4617                         return expected_expression_error();
4618                 }
4619
4620                 parser = &expression_parsers[token.type];
4621                 if(parser->infix_parser == NULL)
4622                         break;
4623                 if(parser->infix_precedence < precedence)
4624                         break;
4625
4626                 left = parser->infix_parser(parser->infix_precedence, left);
4627
4628                 assert(left != NULL);
4629                 assert(left->kind != EXPR_UNKNOWN);
4630                 left->base.source_position = source_position;
4631         }
4632
4633         return left;
4634 }
4635
4636 /**
4637  * Parse an expression.
4638  */
4639 static expression_t *parse_expression(void)
4640 {
4641         return parse_sub_expression(1);
4642 }
4643
4644 /**
4645  * Register a parser for a prefix-like operator with given precedence.
4646  *
4647  * @param parser      the parser function
4648  * @param token_type  the token type of the prefix token
4649  * @param precedence  the precedence of the operator
4650  */
4651 static void register_expression_parser(parse_expression_function parser,
4652                                        int token_type, unsigned precedence)
4653 {
4654         expression_parser_function_t *entry = &expression_parsers[token_type];
4655
4656         if(entry->parser != NULL) {
4657                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
4658                 panic("trying to register multiple expression parsers for a token");
4659         }
4660         entry->parser     = parser;
4661         entry->precedence = precedence;
4662 }
4663
4664 /**
4665  * Register a parser for an infix operator with given precedence.
4666  *
4667  * @param parser      the parser function
4668  * @param token_type  the token type of the infix operator
4669  * @param precedence  the precedence of the operator
4670  */
4671 static void register_infix_parser(parse_expression_infix_function parser,
4672                 int token_type, unsigned precedence)
4673 {
4674         expression_parser_function_t *entry = &expression_parsers[token_type];
4675
4676         if(entry->infix_parser != NULL) {
4677                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
4678                 panic("trying to register multiple infix expression parsers for a "
4679                       "token");
4680         }
4681         entry->infix_parser     = parser;
4682         entry->infix_precedence = precedence;
4683 }
4684
4685 /**
4686  * Initialize the expression parsers.
4687  */
4688 static void init_expression_parsers(void)
4689 {
4690         memset(&expression_parsers, 0, sizeof(expression_parsers));
4691
4692         register_infix_parser(parse_array_expression,         '[',              30);
4693         register_infix_parser(parse_call_expression,          '(',              30);
4694         register_infix_parser(parse_select_expression,        '.',              30);
4695         register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
4696         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
4697                                                               T_PLUSPLUS,       30);
4698         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
4699                                                               T_MINUSMINUS,     30);
4700
4701         register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
4702         register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
4703         register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
4704         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
4705         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
4706         register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
4707         register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
4708         register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
4709         register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
4710         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
4711         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
4712         register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
4713         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
4714                                                     T_EXCLAMATIONMARKEQUAL, 13);
4715         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
4716         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
4717         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
4718         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
4719         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
4720         register_infix_parser(parse_conditional_expression,   '?',               7);
4721         register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
4722         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
4723         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
4724         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
4725         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
4726         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
4727         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
4728                                                                 T_LESSLESSEQUAL, 2);
4729         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4730                                                           T_GREATERGREATEREQUAL, 2);
4731         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
4732                                                                      T_ANDEQUAL, 2);
4733         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
4734                                                                     T_PIPEEQUAL, 2);
4735         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
4736                                                                    T_CARETEQUAL, 2);
4737
4738         register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
4739
4740         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
4741         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
4742         register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
4743         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
4744         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
4745         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
4746         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
4747                                                                   T_PLUSPLUS,   25);
4748         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
4749                                                                   T_MINUSMINUS, 25);
4750         register_expression_parser(parse_sizeof,                  T_sizeof,     25);
4751         register_expression_parser(parse_extension,            T___extension__, 25);
4752         register_expression_parser(parse_builtin_classify_type,
4753                                                      T___builtin_classify_type, 25);
4754 }
4755
4756 /**
4757  * Parse a asm statement constraints specification.
4758  */
4759 static asm_constraint_t *parse_asm_constraints(void)
4760 {
4761         asm_constraint_t *result = NULL;
4762         asm_constraint_t *last   = NULL;
4763
4764         while(token.type == T_STRING_LITERAL || token.type == '[') {
4765                 asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
4766                 memset(constraint, 0, sizeof(constraint[0]));
4767
4768                 if(token.type == '[') {
4769                         eat('[');
4770                         if(token.type != T_IDENTIFIER) {
4771                                 parse_error_expected("while parsing asm constraint",
4772                                                      T_IDENTIFIER, 0);
4773                                 return NULL;
4774                         }
4775                         constraint->symbol = token.v.symbol;
4776
4777                         expect(']');
4778                 }
4779
4780                 constraint->constraints = parse_string_literals();
4781                 expect('(');
4782                 constraint->expression = parse_expression();
4783                 expect(')');
4784
4785                 if(last != NULL) {
4786                         last->next = constraint;
4787                 } else {
4788                         result = constraint;
4789                 }
4790                 last = constraint;
4791
4792                 if(token.type != ',')
4793                         break;
4794                 eat(',');
4795         }
4796
4797         return result;
4798 }
4799
4800 /**
4801  * Parse a asm statement clobber specification.
4802  */
4803 static asm_clobber_t *parse_asm_clobbers(void)
4804 {
4805         asm_clobber_t *result = NULL;
4806         asm_clobber_t *last   = NULL;
4807
4808         while(token.type == T_STRING_LITERAL) {
4809                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
4810                 clobber->clobber       = parse_string_literals();
4811
4812                 if(last != NULL) {
4813                         last->next = clobber;
4814                 } else {
4815                         result = clobber;
4816                 }
4817                 last = clobber;
4818
4819                 if(token.type != ',')
4820                         break;
4821                 eat(',');
4822         }
4823
4824         return result;
4825 }
4826
4827 /**
4828  * Parse an asm statement.
4829  */
4830 static statement_t *parse_asm_statement(void)
4831 {
4832         eat(T_asm);
4833
4834         statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
4835         statement->base.source_position = token.source_position;
4836
4837         asm_statement_t *asm_statement = &statement->asms;
4838
4839         if(token.type == T_volatile) {
4840                 next_token();
4841                 asm_statement->is_volatile = true;
4842         }
4843
4844         expect('(');
4845         asm_statement->asm_text = parse_string_literals();
4846
4847         if(token.type != ':')
4848                 goto end_of_asm;
4849         eat(':');
4850
4851         asm_statement->inputs = parse_asm_constraints();
4852         if(token.type != ':')
4853                 goto end_of_asm;
4854         eat(':');
4855
4856         asm_statement->outputs = parse_asm_constraints();
4857         if(token.type != ':')
4858                 goto end_of_asm;
4859         eat(':');
4860
4861         asm_statement->clobbers = parse_asm_clobbers();
4862
4863 end_of_asm:
4864         expect(')');
4865         expect(';');
4866         return statement;
4867 }
4868
4869 /**
4870  * Parse a case statement.
4871  */
4872 static statement_t *parse_case_statement(void)
4873 {
4874         eat(T_case);
4875
4876         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
4877
4878         statement->base.source_position  = token.source_position;
4879         statement->case_label.expression = parse_expression();
4880
4881         expect(':');
4882
4883         if (! is_constant_expression(statement->case_label.expression)) {
4884                 errorf(statement->base.source_position,
4885                         "case label does not reduce to an integer constant");
4886         } else {
4887                 /* TODO: check if the case label is already known */
4888                 if (current_switch != NULL) {
4889                         /* link all cases into the switch statement */
4890                         if (current_switch->last_case == NULL) {
4891                                 current_switch->first_case =
4892                                 current_switch->last_case  = &statement->case_label;
4893                         } else {
4894                                 current_switch->last_case->next = &statement->case_label;
4895                         }
4896                 } else {
4897                         errorf(statement->base.source_position,
4898                                 "case label not within a switch statement");
4899                 }
4900         }
4901         statement->case_label.label_statement = parse_statement();
4902
4903         return statement;
4904 }
4905
4906 /**
4907  * Finds an existing default label of a switch statement.
4908  */
4909 static case_label_statement_t *
4910 find_default_label(const switch_statement_t *statement)
4911 {
4912         for (case_label_statement_t *label = statement->first_case;
4913              label != NULL;
4914                  label = label->next) {
4915                 if (label->expression == NULL)
4916                         return label;
4917         }
4918         return NULL;
4919 }
4920
4921 /**
4922  * Parse a default statement.
4923  */
4924 static statement_t *parse_default_statement(void)
4925 {
4926         eat(T_default);
4927
4928         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
4929
4930         statement->base.source_position = token.source_position;
4931
4932         expect(':');
4933         if (current_switch != NULL) {
4934                 const case_label_statement_t *def_label = find_default_label(current_switch);
4935                 if (def_label != NULL) {
4936                         errorf(HERE, "multiple default labels in one switch");
4937                         errorf(def_label->statement.source_position,
4938                                 "this is the first default label");
4939                 } else {
4940                         /* link all cases into the switch statement */
4941                         if (current_switch->last_case == NULL) {
4942                                 current_switch->first_case =
4943                                         current_switch->last_case  = &statement->case_label;
4944                         } else {
4945                                 current_switch->last_case->next = &statement->case_label;
4946                         }
4947                 }
4948         } else {
4949                 errorf(statement->base.source_position,
4950                         "'default' label not within a switch statement");
4951         }
4952         statement->label.label_statement = parse_statement();
4953
4954         return statement;
4955 }
4956
4957 /**
4958  * Return the declaration for a given label symbol or create a new one.
4959  */
4960 static declaration_t *get_label(symbol_t *symbol)
4961 {
4962         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
4963         assert(current_function != NULL);
4964         /* if we found a label in the same function, then we already created the
4965          * declaration */
4966         if(candidate != NULL
4967                         && candidate->parent_context == &current_function->context) {
4968                 return candidate;
4969         }
4970
4971         /* otherwise we need to create a new one */
4972         declaration_t *declaration = allocate_ast_zero(sizeof(declaration[0]));
4973         declaration->namespc       = NAMESPACE_LABEL;
4974         declaration->symbol        = symbol;
4975
4976         label_push(declaration);
4977
4978         return declaration;
4979 }
4980
4981 /**
4982  * Parse a label statement.
4983  */
4984 static statement_t *parse_label_statement(void)
4985 {
4986         assert(token.type == T_IDENTIFIER);
4987         symbol_t *symbol = token.v.symbol;
4988         next_token();
4989
4990         declaration_t *label = get_label(symbol);
4991
4992         /* if source position is already set then the label is defined twice,
4993          * otherwise it was just mentioned in a goto so far */
4994         if(label->source_position.input_name != NULL) {
4995                 errorf(HERE, "duplicate label '%Y'", symbol);
4996                 errorf(label->source_position, "previous definition of '%Y' was here",
4997                        symbol);
4998         } else {
4999                 label->source_position = token.source_position;
5000         }
5001
5002         label_statement_t *label_statement = allocate_ast_zero(sizeof(label[0]));
5003
5004         label_statement->statement.kind            = STATEMENT_LABEL;
5005         label_statement->statement.source_position = token.source_position;
5006         label_statement->label                     = label;
5007
5008         eat(':');
5009
5010         if(token.type == '}') {
5011                 /* TODO only warn? */
5012                 errorf(HERE, "label at end of compound statement");
5013                 return (statement_t*) label_statement;
5014         } else {
5015                 label_statement->label_statement = parse_statement();
5016         }
5017
5018         return (statement_t*) label_statement;
5019 }
5020
5021 /**
5022  * Parse an if statement.
5023  */
5024 static statement_t *parse_if(void)
5025 {
5026         eat(T_if);
5027
5028         if_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5029         statement->statement.kind            = STATEMENT_IF;
5030         statement->statement.source_position = token.source_position;
5031
5032         expect('(');
5033         statement->condition = parse_expression();
5034         expect(')');
5035
5036         statement->true_statement = parse_statement();
5037         if(token.type == T_else) {
5038                 next_token();
5039                 statement->false_statement = parse_statement();
5040         }
5041
5042         return (statement_t*) statement;
5043 }
5044
5045 /**
5046  * Parse a switch statement.
5047  */
5048 static statement_t *parse_switch(void)
5049 {
5050         eat(T_switch);
5051
5052         switch_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5053         statement->statement.kind            = STATEMENT_SWITCH;
5054         statement->statement.source_position = token.source_position;
5055
5056         expect('(');
5057         expression_t *const expr = parse_expression();
5058         type_t       *const type = promote_integer(skip_typeref(expr->base.datatype));
5059         statement->expression = create_implicit_cast(expr, type);
5060         expect(')');
5061
5062         switch_statement_t *rem = current_switch;
5063         current_switch  = statement;
5064         statement->body = parse_statement();
5065         current_switch  = rem;
5066
5067         return (statement_t*) statement;
5068 }
5069
5070 /**
5071  * Parse a while statement.
5072  */
5073 static statement_t *parse_while(void)
5074 {
5075         eat(T_while);
5076
5077         while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5078         statement->statement.kind            = STATEMENT_WHILE;
5079         statement->statement.source_position = token.source_position;
5080
5081         statement_t *rem = current_loop;
5082         expect_fail('(');
5083         statement->condition = parse_expression();
5084         expect_fail(')');
5085
5086         statement->body = parse_statement();
5087         current_loop = rem;
5088
5089         return (statement_t*) statement;
5090 fail:
5091         current_loop = rem;
5092         return NULL;
5093 }
5094
5095 /**
5096  * Parse a do statement.
5097  */
5098 static statement_t *parse_do(void)
5099 {
5100         eat(T_do);
5101
5102         do_while_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5103         statement->statement.kind            = STATEMENT_DO_WHILE;
5104         statement->statement.source_position = token.source_position;
5105
5106         statement_t *rem = current_loop;
5107         statement->body = parse_statement();
5108         expect_fail(T_while);
5109         expect_fail('(');
5110         statement->condition = parse_expression();
5111         expect_fail(')');
5112         current_loop = rem;
5113         expect(';');
5114
5115         return (statement_t*) statement;
5116 fail:
5117         current_loop = rem;
5118         return NULL;
5119 }
5120
5121 /**
5122  * Parse a for statement.
5123  */
5124 static statement_t *parse_for(void)
5125 {
5126         eat(T_for);
5127
5128         for_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5129         statement->statement.kind            = STATEMENT_FOR;
5130         statement->statement.source_position = token.source_position;
5131
5132         expect('(');
5133
5134         statement_t *rem = current_loop;
5135         int         top          = environment_top();
5136         context_t  *last_context = context;
5137         set_context(&statement->context);
5138
5139         if(token.type != ';') {
5140                 if(is_declaration_specifier(&token, false)) {
5141                         parse_declaration(record_declaration);
5142                 } else {
5143                         statement->initialisation = parse_expression();
5144                         expect_fail(';');
5145                 }
5146         } else {
5147                 expect_fail(';');
5148         }
5149
5150         if(token.type != ';') {
5151                 statement->condition = parse_expression();
5152         }
5153         expect_fail(';');
5154         if(token.type != ')') {
5155                 statement->step = parse_expression();
5156         }
5157         expect_fail(')');
5158         statement->body = parse_statement();
5159
5160         assert(context == &statement->context);
5161         set_context(last_context);
5162         environment_pop_to(top);
5163         current_loop = rem;
5164
5165         return (statement_t*) statement;
5166 fail:
5167         current_loop = rem;
5168         return NULL;
5169 }
5170
5171 /**
5172  * Parse a goto statement.
5173  */
5174 static statement_t *parse_goto(void)
5175 {
5176         eat(T_goto);
5177
5178         if(token.type != T_IDENTIFIER) {
5179                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
5180                 eat_statement();
5181                 return NULL;
5182         }
5183         symbol_t *symbol = token.v.symbol;
5184         next_token();
5185
5186         declaration_t *label = get_label(symbol);
5187
5188         goto_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5189
5190         statement->statement.kind            = STATEMENT_GOTO;
5191         statement->statement.source_position = token.source_position;
5192
5193         statement->label = label;
5194
5195         /* remember the goto's in a list for later checking */
5196         statement->next = goto_list;
5197         goto_list       = statement;
5198
5199         expect(';');
5200
5201         return (statement_t*) statement;
5202 }
5203
5204 /**
5205  * Parse a continue statement.
5206  */
5207 static statement_t *parse_continue(void)
5208 {
5209         eat(T_continue);
5210         expect(';');
5211
5212         statement_t *statement          = allocate_ast_zero(sizeof(statement[0]));
5213         statement->kind                 = STATEMENT_CONTINUE;
5214         statement->base.source_position = token.source_position;
5215
5216         if (current_loop == NULL) {
5217                 errorf(HERE, "continue statement not within loop");
5218                 return NULL;
5219         }
5220
5221         return statement;
5222 }
5223
5224 /**
5225  * Parse a break statement.
5226  */
5227 static statement_t *parse_break(void)
5228 {
5229         eat(T_break);
5230         expect(';');
5231
5232         statement_t *statement          = allocate_ast_zero(sizeof(statement[0]));
5233         statement->kind                 = STATEMENT_BREAK;
5234         statement->base.source_position = token.source_position;
5235
5236         if (current_switch == NULL && current_loop == NULL) {
5237                 errorf(HERE, "break statement not within loop or switch");
5238                 return NULL;
5239         }
5240         return statement;
5241 }
5242
5243 /**
5244  * Check if a given declaration represents a local variable.
5245  */
5246 static bool is_local_var_declaration(const declaration_t *declaration) {
5247         switch ((storage_class_tag_t) declaration->storage_class) {
5248         case STORAGE_CLASS_NONE:
5249         case STORAGE_CLASS_AUTO:
5250         case STORAGE_CLASS_REGISTER: {
5251                 const type_t *type = skip_typeref(declaration->type);
5252                 if(is_type_function(type)) {
5253                         return false;
5254                 } else {
5255                         return true;
5256                 }
5257         }
5258         default:
5259                 return false;
5260         }
5261 }
5262
5263 /**
5264  * Check if a given expression represents a local variable.
5265  */
5266 static bool is_local_variable(const expression_t *expression)
5267 {
5268         if (expression->base.kind != EXPR_REFERENCE) {
5269                 return false;
5270         }
5271         const declaration_t *declaration = expression->reference.declaration;
5272         return is_local_var_declaration(declaration);
5273 }
5274
5275 /**
5276  * Parse a return statement.
5277  */
5278 static statement_t *parse_return(void)
5279 {
5280         eat(T_return);
5281
5282         return_statement_t *statement = allocate_ast_zero(sizeof(statement[0]));
5283
5284         statement->statement.kind            = STATEMENT_RETURN;
5285         statement->statement.source_position = token.source_position;
5286
5287         assert(is_type_function(current_function->type));
5288         function_type_t *function_type = &current_function->type->function;
5289         type_t          *return_type   = function_type->return_type;
5290
5291         expression_t *return_value = NULL;
5292         if(token.type != ';') {
5293                 return_value = parse_expression();
5294         }
5295         expect(';');
5296
5297         if(return_type == NULL)
5298                 return (statement_t*) statement;
5299         if(return_value != NULL && return_value->base.datatype == NULL)
5300                 return (statement_t*) statement;
5301
5302         return_type = skip_typeref(return_type);
5303
5304         if(return_value != NULL) {
5305                 type_t *return_value_type = skip_typeref(return_value->base.datatype);
5306
5307                 if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
5308                                 && !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
5309                         warningf(statement->statement.source_position,
5310                                 "'return' with a value, in function returning void");
5311                         return_value = NULL;
5312                 } else {
5313                         if(return_type != NULL) {
5314                                 semantic_assign(return_type, &return_value, "'return'");
5315                         }
5316                 }
5317                 /* check for returning address of a local var */
5318                 if (return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
5319                         const expression_t *expression = return_value->unary.value;
5320                         if (is_local_variable(expression)) {
5321                                 warningf(statement->statement.source_position,
5322                                         "function returns address of local variable");
5323                         }
5324                 }
5325         } else {
5326                 if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
5327                         warningf(statement->statement.source_position,
5328                                 "'return' without value, in function returning non-void");
5329                 }
5330         }
5331         statement->return_value = return_value;
5332
5333         return (statement_t*) statement;
5334 }
5335
5336 /**
5337  * Parse a declaration statement.
5338  */
5339 static statement_t *parse_declaration_statement(void)
5340 {
5341         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
5342
5343         statement->base.source_position = token.source_position;
5344
5345         declaration_t *before = last_declaration;
5346         parse_declaration(record_declaration);
5347
5348         if(before == NULL) {
5349                 statement->declaration.declarations_begin = context->declarations;
5350         } else {
5351                 statement->declaration.declarations_begin = before->next;
5352         }
5353         statement->declaration.declarations_end = last_declaration;
5354
5355         return statement;
5356 }
5357
5358 /**
5359  * Parse an expression statement, ie. expr ';'.
5360  */
5361 static statement_t *parse_expression_statement(void)
5362 {
5363         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
5364
5365         statement->base.source_position  = token.source_position;
5366         statement->expression.expression = parse_expression();
5367
5368         expect(';');
5369
5370         return statement;
5371 }
5372
5373 /**
5374  * Parse a statement.
5375  */
5376 static statement_t *parse_statement(void)
5377 {
5378         statement_t   *statement = NULL;
5379
5380         /* declaration or statement */
5381         switch(token.type) {
5382         case T_asm:
5383                 statement = parse_asm_statement();
5384                 break;
5385
5386         case T_case:
5387                 statement = parse_case_statement();
5388                 break;
5389
5390         case T_default:
5391                 statement = parse_default_statement();
5392                 break;
5393
5394         case '{':
5395                 statement = parse_compound_statement();
5396                 break;
5397
5398         case T_if:
5399                 statement = parse_if();
5400                 break;
5401
5402         case T_switch:
5403                 statement = parse_switch();
5404                 break;
5405
5406         case T_while:
5407                 statement = parse_while();
5408                 break;
5409
5410         case T_do:
5411                 statement = parse_do();
5412                 break;
5413
5414         case T_for:
5415                 statement = parse_for();
5416                 break;
5417
5418         case T_goto:
5419                 statement = parse_goto();
5420                 break;
5421
5422         case T_continue:
5423                 statement = parse_continue();
5424                 break;
5425
5426         case T_break:
5427                 statement = parse_break();
5428                 break;
5429
5430         case T_return:
5431                 statement = parse_return();
5432                 break;
5433
5434         case ';':
5435                 next_token();
5436                 statement = NULL;
5437                 break;
5438
5439         case T_IDENTIFIER:
5440                 if(look_ahead(1)->type == ':') {
5441                         statement = parse_label_statement();
5442                         break;
5443                 }
5444
5445                 if(is_typedef_symbol(token.v.symbol)) {
5446                         statement = parse_declaration_statement();
5447                         break;
5448                 }
5449
5450                 statement = parse_expression_statement();
5451                 break;
5452
5453         case T___extension__:
5454                 /* this can be a prefix to a declaration or an expression statement */
5455                 /* we simply eat it now and parse the rest with tail recursion */
5456                 do {
5457                         next_token();
5458                 } while(token.type == T___extension__);
5459                 statement = parse_statement();
5460                 break;
5461
5462         DECLARATION_START
5463                 statement = parse_declaration_statement();
5464                 break;
5465
5466         default:
5467                 statement = parse_expression_statement();
5468                 break;
5469         }
5470
5471         assert(statement == NULL
5472                         || statement->base.source_position.input_name != NULL);
5473
5474         return statement;
5475 }
5476
5477 /**
5478  * Parse a compound statement.
5479  */
5480 static statement_t *parse_compound_statement(void)
5481 {
5482         compound_statement_t *compound_statement
5483                 = allocate_ast_zero(sizeof(compound_statement[0]));
5484         compound_statement->statement.kind            = STATEMENT_COMPOUND;
5485         compound_statement->statement.source_position = token.source_position;
5486
5487         eat('{');
5488
5489         int        top          = environment_top();
5490         context_t *last_context = context;
5491         set_context(&compound_statement->context);
5492
5493         statement_t *last_statement = NULL;
5494
5495         while(token.type != '}' && token.type != T_EOF) {
5496                 statement_t *statement = parse_statement();
5497                 if(statement == NULL)
5498                         continue;
5499
5500                 if(last_statement != NULL) {
5501                         last_statement->base.next = statement;
5502                 } else {
5503                         compound_statement->statements = statement;
5504                 }
5505
5506                 while(statement->base.next != NULL)
5507                         statement = statement->base.next;
5508
5509                 last_statement = statement;
5510         }
5511
5512         if(token.type == '}') {
5513                 next_token();
5514         } else {
5515                 errorf(compound_statement->statement.source_position, "end of file while looking for closing '}'");
5516         }
5517
5518         assert(context == &compound_statement->context);
5519         set_context(last_context);
5520         environment_pop_to(top);
5521
5522         return (statement_t*) compound_statement;
5523 }
5524
5525 /**
5526  * Initialize builtin types.
5527  */
5528 static void initialize_builtin_types(void)
5529 {
5530         type_intmax_t    = make_global_typedef("__intmax_t__",      type_long_long);
5531         type_size_t      = make_global_typedef("__SIZE_TYPE__",     type_unsigned_long);
5532         type_ssize_t     = make_global_typedef("__SSIZE_TYPE__",    type_long);
5533         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
5534         type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
5535         type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
5536         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    type_int);
5537         type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
5538
5539         type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
5540         type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
5541         type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
5542         type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
5543 }
5544
5545 /**
5546  * Parse a translation unit.
5547  */
5548 static translation_unit_t *parse_translation_unit(void)
5549 {
5550         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
5551
5552         assert(global_context == NULL);
5553         global_context = &unit->context;
5554
5555         assert(context == NULL);
5556         set_context(&unit->context);
5557
5558         initialize_builtin_types();
5559
5560         while(token.type != T_EOF) {
5561                 if (token.type == ';') {
5562                         /* TODO error in strict mode */
5563                         warningf(HERE, "stray ';' outside of function");
5564                         next_token();
5565                 } else {
5566                         parse_external_declaration();
5567                 }
5568         }
5569
5570         assert(context == &unit->context);
5571         context          = NULL;
5572         last_declaration = NULL;
5573
5574         assert(global_context == &unit->context);
5575         global_context = NULL;
5576
5577         return unit;
5578 }
5579
5580 /**
5581  * Parse the input.
5582  *
5583  * @return  the translation unit or NULL if errors occurred.
5584  */
5585 translation_unit_t *parse(void)
5586 {
5587         environment_stack = NEW_ARR_F(stack_entry_t, 0);
5588         label_stack       = NEW_ARR_F(stack_entry_t, 0);
5589         diagnostic_count  = 0;
5590         error_count       = 0;
5591         warning_count     = 0;
5592
5593         type_set_output(stderr);
5594         ast_set_output(stderr);
5595
5596         lookahead_bufpos = 0;
5597         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
5598                 next_token();
5599         }
5600         translation_unit_t *unit = parse_translation_unit();
5601
5602         DEL_ARR_F(environment_stack);
5603         DEL_ARR_F(label_stack);
5604
5605         if(error_count > 0)
5606                 return NULL;
5607
5608         return unit;
5609 }
5610
5611 /**
5612  * Initialize the parser.
5613  */
5614 void init_parser(void)
5615 {
5616         init_expression_parsers();
5617         obstack_init(&temp_obst);
5618
5619         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
5620         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
5621 }
5622
5623 /**
5624  * Terminate the parser.
5625  */
5626 void exit_parser(void)
5627 {
5628         obstack_free(&temp_obst, NULL);
5629 }