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 "warning.h"
  18 #include "adt/bitfiddle.h"
  19 #include "adt/error.h"
  20 #include "adt/array.h"
  21
  22 //#define PRINT_TOKENS
  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      declared_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 scope_t            *global_scope      = NULL;
  48 static scope_t            *scope             = 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_first        = NULL;
  54 static goto_statement_t   *goto_last         = NULL;
  55 static label_statement_t  *label_first       = NULL;
  56 static label_statement_t  *label_last        = NULL;
  57 static struct obstack      temp_obst;
  58
  59 /** The current source position. */
  60 #define HERE token.source_position
  61
  62 static type_t *type_valist;
  63
  64 static statement_t *parse_compound_statement(void);
  65 static statement_t *parse_statement(void);
  66
  67 static expression_t *parse_sub_expression(unsigned precedence);
  68 static expression_t *parse_expression(void);
  69 static type_t       *parse_typename(void);
  70
  71 static void parse_compound_type_entries(declaration_t *compound_declaration);
  72 static declaration_t *parse_declarator(
  73                 const declaration_specifiers_t *specifiers, bool may_be_abstract);
  74 static declaration_t *record_declaration(declaration_t *declaration);
  75
  76 static void semantic_comparison(binary_expression_t *expression);
  77
  78 #define STORAGE_CLASSES     \
  79         case T_typedef:         \
  80         case T_extern:          \
  81         case T_static:          \
  82         case T_auto:            \
  83         case T_register:
  84
  85 #define TYPE_QUALIFIERS     \
  86         case T_const:           \
  87         case T_restrict:        \
  88         case T_volatile:        \
  89         case T_inline:          \
  90         case T_forceinline:
  91
  92 #ifdef PROVIDE_COMPLEX
  93 #define COMPLEX_SPECIFIERS  \
  94         case T__Complex:
  95 #define IMAGINARY_SPECIFIERS \
  96         case T__Imaginary:
  97 #else
  98 #define COMPLEX_SPECIFIERS
  99 #define IMAGINARY_SPECIFIERS
 100 #endif
 101
 102 #define TYPE_SPECIFIERS       \
 103         case T_void:              \
 104         case T_char:              \
 105         case T_short:             \
 106         case T_int:               \
 107         case T_long:              \
 108         case T_float:             \
 109         case T_double:            \
 110         case T_signed:            \
 111         case T_unsigned:          \
 112         case T__Bool:             \
 113         case T_struct:            \
 114         case T_union:             \
 115         case T_enum:              \
 116         case T___typeof__:        \
 117         case T___builtin_va_list: \
 118         COMPLEX_SPECIFIERS        \
 119         IMAGINARY_SPECIFIERS
 120
 121 #define DECLARATION_START   \
 122         STORAGE_CLASSES         \
 123         TYPE_QUALIFIERS         \
 124         TYPE_SPECIFIERS
 125
 126 #define TYPENAME_START      \
 127         TYPE_QUALIFIERS         \
 128         TYPE_SPECIFIERS
 129
 130 /**
 131  * Allocate an AST node with given size and
 132  * initialize all fields with zero.
 133  */
 134 static void *allocate_ast_zero(size_t size)
 135 {
 136         void *res = allocate_ast(size);
 137         memset(res, 0, size);
 138         return res;
 139 }
 140
 141 static declaration_t *allocate_declaration_zero(void)
 142 {
 143         declaration_t *declaration = allocate_ast_zero(sizeof(declaration_t));
 144         declaration->type = type_error_type;
 145         return declaration;
 146 }
 147
 148 /**
 149  * Returns the size of a statement node.
 150  *
 151  * @param kind  the statement kind
 152  */
 153 static size_t get_statement_struct_size(statement_kind_t kind)
 154 {
 155         static const size_t sizes[] = {
 156                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 157                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 158                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 159                 [STATEMENT_IF]          = sizeof(if_statement_t),
 160                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 161                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 162                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 163                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 164                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 165                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 166                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 167                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 168                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 169                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 170                 [STATEMENT_ASM]         = sizeof(asm_statement_t)
 171         };
 172         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 173         assert(sizes[kind] != 0);
 174         return sizes[kind];
 175 }
 176
 177 /**
 178  * Allocate a statement node of given kind and initialize all
 179  * fields with zero.
 180  */
 181 static statement_t *allocate_statement_zero(statement_kind_t kind)
 182 {
 183         size_t       size = get_statement_struct_size(kind);
 184         statement_t *res  = allocate_ast_zero(size);
 185
 186         res->base.kind = kind;
 187         return res;
 188 }
 189
 190 /**
 191  * Returns the size of an expression node.
 192  *
 193  * @param kind  the expression kind
 194  */
 195 static size_t get_expression_struct_size(expression_kind_t kind)
 196 {
 197         static const size_t sizes[] = {
 198                 [EXPR_INVALID]             = sizeof(expression_base_t),
 199                 [EXPR_REFERENCE]           = sizeof(reference_expression_t),
 200                 [EXPR_CONST]               = sizeof(const_expression_t),
 201                 [EXPR_CHAR_CONST]          = sizeof(const_expression_t),
 202                 [EXPR_STRING_LITERAL]      = sizeof(string_literal_expression_t),
 203                 [EXPR_WIDE_STRING_LITERAL] = sizeof(wide_string_literal_expression_t),
 204                 [EXPR_COMPOUND_LITERAL]    = sizeof(compound_literal_expression_t),
 205                 [EXPR_CALL]                = sizeof(call_expression_t),
 206                 [EXPR_UNARY_FIRST]         = sizeof(unary_expression_t),
 207                 [EXPR_BINARY_FIRST]        = sizeof(binary_expression_t),
 208                 [EXPR_CONDITIONAL]         = sizeof(conditional_expression_t),
 209                 [EXPR_SELECT]              = sizeof(select_expression_t),
 210                 [EXPR_ARRAY_ACCESS]        = sizeof(array_access_expression_t),
 211                 [EXPR_SIZEOF]              = sizeof(typeprop_expression_t),
 212                 [EXPR_ALIGNOF]             = sizeof(typeprop_expression_t),
 213                 [EXPR_CLASSIFY_TYPE]       = sizeof(classify_type_expression_t),
 214                 [EXPR_FUNCTION]            = sizeof(string_literal_expression_t),
 215                 [EXPR_PRETTY_FUNCTION]     = sizeof(string_literal_expression_t),
 216                 [EXPR_BUILTIN_SYMBOL]      = sizeof(builtin_symbol_expression_t),
 217                 [EXPR_BUILTIN_CONSTANT_P]  = sizeof(builtin_constant_expression_t),
 218                 [EXPR_BUILTIN_PREFETCH]    = sizeof(builtin_prefetch_expression_t),
 219                 [EXPR_OFFSETOF]            = sizeof(offsetof_expression_t),
 220                 [EXPR_VA_START]            = sizeof(va_start_expression_t),
 221                 [EXPR_VA_ARG]              = sizeof(va_arg_expression_t),
 222                 [EXPR_STATEMENT]           = sizeof(statement_expression_t),
 223         };
 224         if(kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 225                 return sizes[EXPR_UNARY_FIRST];
 226         }
 227         if(kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 228                 return sizes[EXPR_BINARY_FIRST];
 229         }
 230         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 231         assert(sizes[kind] != 0);
 232         return sizes[kind];
 233 }
 234
 235 /**
 236  * Allocate an expression node of given kind and initialize all
 237  * fields with zero.
 238  */
 239 static expression_t *allocate_expression_zero(expression_kind_t kind)
 240 {
 241         size_t        size = get_expression_struct_size(kind);
 242         expression_t *res  = allocate_ast_zero(size);
 243
 244         res->base.kind = kind;
 245         res->base.type = type_error_type;
 246         return res;
 247 }
 248
 249 /**
 250  * Returns the size of a type node.
 251  *
 252  * @param kind  the type kind
 253  */
 254 static size_t get_type_struct_size(type_kind_t kind)
 255 {
 256         static const size_t sizes[] = {
 257                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 258                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 259                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 260                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 261                 [TYPE_ENUM]            = sizeof(enum_type_t),
 262                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 263                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 264                 [TYPE_ARRAY]           = sizeof(array_type_t),
 265                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 266                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 267                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 268         };
 269         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 270         assert(kind <= TYPE_TYPEOF);
 271         assert(sizes[kind] != 0);
 272         return sizes[kind];
 273 }
 274
 275 /**
 276  * Allocate a type node of given kind and initialize all
 277  * fields with zero.
 278  */
 279 static type_t *allocate_type_zero(type_kind_t kind, source_position_t source_position)
 280 {
 281         size_t  size = get_type_struct_size(kind);
 282         type_t *res  = obstack_alloc(type_obst, size);
 283         memset(res, 0, size);
 284
 285         res->base.kind            = kind;
 286         res->base.source_position = source_position;
 287         return res;
 288 }
 289
 290 /**
 291  * Returns the size of an initializer node.
 292  *
 293  * @param kind  the initializer kind
 294  */
 295 static size_t get_initializer_size(initializer_kind_t kind)
 296 {
 297         static const size_t sizes[] = {
 298                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 299                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 300                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 301                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 302                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 303         };
 304         assert(kind < sizeof(sizes) / sizeof(*sizes));
 305         assert(sizes[kind] != 0);
 306         return sizes[kind];
 307 }
 308
 309 /**
 310  * Allocate an initializer node of given kind and initialize all
 311  * fields with zero.
 312  */
 313 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 314 {
 315         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 316         result->kind          = kind;
 317
 318         return result;
 319 }
 320
 321 /**
 322  * Free a type from the type obstack.
 323  */
 324 static void free_type(void *type)
 325 {
 326         obstack_free(type_obst, type);
 327 }
 328
 329 /**
 330  * Returns the index of the top element of the environment stack.
 331  */
 332 static size_t environment_top(void)
 333 {
 334         return ARR_LEN(environment_stack);
 335 }
 336
 337 /**
 338  * Returns the index of the top element of the label stack.
 339  */
 340 static size_t label_top(void)
 341 {
 342         return ARR_LEN(label_stack);
 343 }
 344
 345
 346 /**
 347  * Return the next token.
 348  */
 349 static inline void next_token(void)
 350 {
 351         token                              = lookahead_buffer[lookahead_bufpos];
 352         lookahead_buffer[lookahead_bufpos] = lexer_token;
 353         lexer_next_token();
 354
 355         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 356
 357 #ifdef PRINT_TOKENS
 358         print_token(stderr, &token);
 359         fprintf(stderr, "\n");
 360 #endif
 361 }
 362
 363 /**
 364  * Return the next token with a given lookahead.
 365  */
 366 static inline const token_t *look_ahead(int num)
 367 {
 368         assert(num > 0 && num <= MAX_LOOKAHEAD);
 369         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 370         return &lookahead_buffer[pos];
 371 }
 372
 373 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
 374
 375 /**
 376  * Report a parse error because an expected token was not found.
 377  */
 378 static void parse_error_expected(const char *message, ...)
 379 {
 380         if(message != NULL) {
 381                 errorf(HERE, "%s", message);
 382         }
 383         va_list ap;
 384         va_start(ap, message);
 385         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 386         va_end(ap);
 387 }
 388
 389 /**
 390  * Report a type error.
 391  */
 392 static void type_error(const char *msg, const source_position_t source_position,
 393                        type_t *type)
 394 {
 395         errorf(source_position, "%s, but found type '%T'", msg, type);
 396 }
 397
 398 /**
 399  * Report an incompatible type.
 400  */
 401 static void type_error_incompatible(const char *msg,
 402                 const source_position_t source_position, type_t *type1, type_t *type2)
 403 {
 404         errorf(source_position, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 405 }
 406
 407 /**
 408  * Eat an complete block, ie. '{ ... }'.
 409  */
 410 static void eat_block(void)
 411 {
 412         if(token.type == '{')
 413                 next_token();
 414
 415         while(token.type != '}') {
 416                 if(token.type == T_EOF)
 417                         return;
 418                 if(token.type == '{') {
 419                         eat_block();
 420                         continue;
 421                 }
 422                 next_token();
 423         }
 424         eat('}');
 425 }
 426
 427 /**
 428  * Eat a statement until an ';' token.
 429  */
 430 static void eat_statement(void)
 431 {
 432         while(token.type != ';') {
 433                 if(token.type == T_EOF)
 434                         return;
 435                 if(token.type == '}')
 436                         return;
 437                 if(token.type == '{') {
 438                         eat_block();
 439                         continue;
 440                 }
 441                 next_token();
 442         }
 443         eat(';');
 444 }
 445
 446 /**
 447  * Eat a parenthesed term, ie. '( ... )'.
 448  */
 449 static void eat_paren(void)
 450 {
 451         if(token.type == '(')
 452                 next_token();
 453
 454         while(token.type != ')') {
 455                 if(token.type == T_EOF)
 456                         return;
 457                 if(token.type == ')' || token.type == ';' || token.type == '}') {
 458                         return;
 459                 }
 460                 if(token.type == '(') {
 461                         eat_paren();
 462                         continue;
 463                 }
 464                 if(token.type == '{') {
 465                         eat_block();
 466                         continue;
 467                 }
 468                 next_token();
 469         }
 470         eat(')');
 471 }
 472
 473 #define expect(expected)                           \
 474         do {                                           \
 475     if(UNLIKELY(token.type != (expected))) {       \
 476         parse_error_expected(NULL, (expected), 0); \
 477         eat_statement();                           \
 478         return NULL;                               \
 479     }                                              \
 480     next_token();                                  \
 481         } while(0)
 482
 483 #define expect_block(expected)                     \
 484         do {                                           \
 485     if(UNLIKELY(token.type != (expected))) {       \
 486         parse_error_expected(NULL, (expected), 0); \
 487         eat_block();                               \
 488         return NULL;                               \
 489     }                                              \
 490     next_token();                                  \
 491         } while(0)
 492
 493 #define expect_void(expected)                      \
 494         do {                                           \
 495     if(UNLIKELY(token.type != (expected))) {       \
 496         parse_error_expected(NULL, (expected), 0); \
 497         eat_statement();                           \
 498         return;                                    \
 499     }                                              \
 500     next_token();                                  \
 501     } while(0)
 502
 503 static void set_scope(scope_t *new_scope)
 504 {
 505         if(scope != NULL) {
 506                 scope->last_declaration = last_declaration;
 507         }
 508         scope = new_scope;
 509
 510         last_declaration = new_scope->last_declaration;
 511 }
 512
 513 /**
 514  * Search a symbol in a given namespace and returns its declaration or
 515  * NULL if this symbol was not found.
 516  */
 517 static declaration_t *get_declaration(const symbol_t *const symbol, const namespace_t namespc)
 518 {
 519         declaration_t *declaration = symbol->declaration;
 520         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 521                 if(declaration->namespc == namespc)
 522                         return declaration;
 523         }
 524
 525         return NULL;
 526 }
 527
 528 /**
 529  * pushs an environment_entry on the environment stack and links the
 530  * corresponding symbol to the new entry
 531  */
 532 static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
 533 {
 534         symbol_t    *symbol  = declaration->symbol;
 535         namespace_t  namespc = (namespace_t) declaration->namespc;
 536
 537         /* replace/add declaration into declaration list of the symbol */
 538         declaration_t *iter = symbol->declaration;
 539         if (iter == NULL) {
 540                 symbol->declaration = declaration;
 541         } else {
 542                 declaration_t *iter_last = NULL;
 543                 for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 544                         /* replace an entry? */
 545                         if(iter->namespc == namespc) {
 546                                 if(iter_last == NULL) {
 547                                         symbol->declaration = declaration;
 548                                 } else {
 549                                         iter_last->symbol_next = declaration;
 550                                 }
 551                                 declaration->symbol_next = iter->symbol_next;
 552                                 break;
 553                         }
 554                 }
 555                 if(iter == NULL) {
 556                         assert(iter_last->symbol_next == NULL);
 557                         iter_last->symbol_next = declaration;
 558                 }
 559         }
 560
 561         /* remember old declaration */
 562         stack_entry_t entry;
 563         entry.symbol          = symbol;
 564         entry.old_declaration = iter;
 565         entry.namespc         = (unsigned short) namespc;
 566         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 567 }
 568
 569 static void environment_push(declaration_t *declaration)
 570 {
 571         assert(declaration->source_position.input_name != NULL);
 572         assert(declaration->parent_scope != NULL);
 573         stack_push(&environment_stack, declaration);
 574 }
 575
 576 static void label_push(declaration_t *declaration)
 577 {
 578         declaration->parent_scope = &current_function->scope;
 579         stack_push(&label_stack, declaration);
 580 }
 581
 582 /**
 583  * pops symbols from the environment stack until @p new_top is the top element
 584  */
 585 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 586 {
 587         stack_entry_t *stack = *stack_ptr;
 588         size_t         top   = ARR_LEN(stack);
 589         size_t         i;
 590
 591         assert(new_top <= top);
 592         if(new_top == top)
 593                 return;
 594
 595         for(i = top; i > new_top; --i) {
 596                 stack_entry_t *entry = &stack[i - 1];
 597
 598                 declaration_t *old_declaration = entry->old_declaration;
 599                 symbol_t      *symbol          = entry->symbol;
 600                 namespace_t    namespc         = (namespace_t)entry->namespc;
 601
 602                 /* replace/remove declaration */
 603                 declaration_t *declaration = symbol->declaration;
 604                 assert(declaration != NULL);
 605                 if(declaration->namespc == namespc) {
 606                         if(old_declaration == NULL) {
 607                                 symbol->declaration = declaration->symbol_next;
 608                         } else {
 609                                 symbol->declaration = old_declaration;
 610                         }
 611                 } else {
 612                         declaration_t *iter_last = declaration;
 613                         declaration_t *iter      = declaration->symbol_next;
 614                         for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 615                                 /* replace an entry? */
 616                                 if(iter->namespc == namespc) {
 617                                         assert(iter_last != NULL);
 618                                         iter_last->symbol_next = old_declaration;
 619                                         if(old_declaration != NULL) {
 620                                                 old_declaration->symbol_next = iter->symbol_next;
 621                                         }
 622                                         break;
 623                                 }
 624                         }
 625                         assert(iter != NULL);
 626                 }
 627         }
 628
 629         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 630 }
 631
 632 static void environment_pop_to(size_t new_top)
 633 {
 634         stack_pop_to(&environment_stack, new_top);
 635 }
 636
 637 static void label_pop_to(size_t new_top)
 638 {
 639         stack_pop_to(&label_stack, new_top);
 640 }
 641
 642
 643 static int get_rank(const type_t *type)
 644 {
 645         assert(!is_typeref(type));
 646         /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
 647          * and esp. footnote 108). However we can't fold constants (yet), so we
 648          * can't decide whether unsigned int is possible, while int always works.
 649          * (unsigned int would be preferable when possible... for stuff like
 650          *  struct { enum { ... } bla : 4; } ) */
 651         if(type->kind == TYPE_ENUM)
 652                 return ATOMIC_TYPE_INT;
 653
 654         assert(type->kind == TYPE_ATOMIC);
 655         return type->atomic.akind;
 656 }
 657
 658 static type_t *promote_integer(type_t *type)
 659 {
 660         if(type->kind == TYPE_BITFIELD)
 661                 type = type->bitfield.base;
 662
 663         if(get_rank(type) < ATOMIC_TYPE_INT)
 664                 type = type_int;
 665
 666         return type;
 667 }
 668
 669 /**
 670  * Create a cast expression.
 671  *
 672  * @param expression  the expression to cast
 673  * @param dest_type   the destination type
 674  */
 675 static expression_t *create_cast_expression(expression_t *expression,
 676                                             type_t *dest_type)
 677 {
 678         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 679
 680         cast->unary.value = expression;
 681         cast->base.type   = dest_type;
 682
 683         return cast;
 684 }
 685
 686 /**
 687  * Check if a given expression represents the 0 pointer constant.
 688  */
 689 static bool is_null_pointer_constant(const expression_t *expression)
 690 {
 691         /* skip void* cast */
 692         if(expression->kind == EXPR_UNARY_CAST
 693                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 694                 expression = expression->unary.value;
 695         }
 696
 697         /* TODO: not correct yet, should be any constant integer expression
 698          * which evaluates to 0 */
 699         if (expression->kind != EXPR_CONST)
 700                 return false;
 701
 702         type_t *const type = skip_typeref(expression->base.type);
 703         if (!is_type_integer(type))
 704                 return false;
 705
 706         return expression->conste.v.int_value == 0;
 707 }
 708
 709 /**
 710  * Create an implicit cast expression.
 711  *
 712  * @param expression  the expression to cast
 713  * @param dest_type   the destination type
 714  */
 715 static expression_t *create_implicit_cast(expression_t *expression,
 716                                           type_t *dest_type)
 717 {
 718         type_t *const source_type = expression->base.type;
 719
 720         if (source_type == dest_type)
 721                 return expression;
 722
 723         return create_cast_expression(expression, dest_type);
 724 }
 725
 726 /** Implements the rules from § 6.5.16.1 */
 727 static type_t *semantic_assign(type_t *orig_type_left,
 728                             const expression_t *const right,
 729                             const char *context)
 730 {
 731         type_t *const orig_type_right = right->base.type;
 732         type_t *const type_left       = skip_typeref(orig_type_left);
 733         type_t *const type_right      = skip_typeref(orig_type_right);
 734
 735         if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 736             (is_type_pointer(type_left) && is_null_pointer_constant(right)) ||
 737             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 738                 && is_type_pointer(type_right))) {
 739                 return orig_type_left;
 740         }
 741
 742         if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
 743                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 744                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 745
 746                 /* the left type has all qualifiers from the right type */
 747                 unsigned missing_qualifiers
 748                         = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 749                 if(missing_qualifiers != 0) {
 750                         errorf(HERE, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointed-to type", type_left, context, type_right, missing_qualifiers);
 751                         return orig_type_left;
 752                 }
 753
 754                 points_to_left  = get_unqualified_type(points_to_left);
 755                 points_to_right = get_unqualified_type(points_to_right);
 756
 757                 if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID) ||
 758                                 is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
 759                         return orig_type_left;
 760                 }
 761
 762                 if (!types_compatible(points_to_left, points_to_right)) {
 763                         warningf(right->base.source_position,
 764                                 "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 765                                 orig_type_left, context, right, orig_type_right);
 766                 }
 767
 768                 return orig_type_left;
 769         }
 770
 771         if ((is_type_compound(type_left)  && is_type_compound(type_right))
 772                         || (is_type_builtin(type_left) && is_type_builtin(type_right))) {
 773                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
 774                 type_t *const unqual_type_right = get_unqualified_type(type_right);
 775                 if (types_compatible(unqual_type_left, unqual_type_right)) {
 776                         return orig_type_left;
 777                 }
 778         }
 779
 780         if (!is_type_valid(type_left))
 781                 return type_left;
 782
 783         if (!is_type_valid(type_right))
 784                 return orig_type_right;
 785
 786         return NULL;
 787 }
 788
 789 static expression_t *parse_constant_expression(void)
 790 {
 791         /* start parsing at precedence 7 (conditional expression) */
 792         expression_t *result = parse_sub_expression(7);
 793
 794         if(!is_constant_expression(result)) {
 795                 errorf(result->base.source_position, "expression '%E' is not constant\n", result);
 796         }
 797
 798         return result;
 799 }
 800
 801 static expression_t *parse_assignment_expression(void)
 802 {
 803         /* start parsing at precedence 2 (assignment expression) */
 804         return parse_sub_expression(2);
 805 }
 806
 807 static type_t *make_global_typedef(const char *name, type_t *type)
 808 {
 809         symbol_t *const symbol       = symbol_table_insert(name);
 810
 811         declaration_t *const declaration = allocate_declaration_zero();
 812         declaration->namespc                = NAMESPACE_NORMAL;
 813         declaration->storage_class          = STORAGE_CLASS_TYPEDEF;
 814         declaration->declared_storage_class = STORAGE_CLASS_TYPEDEF;
 815         declaration->type                   = type;
 816         declaration->symbol                 = symbol;
 817         declaration->source_position        = builtin_source_position;
 818
 819         record_declaration(declaration);
 820
 821         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF, builtin_source_position);
 822         typedef_type->typedeft.declaration = declaration;
 823
 824         return typedef_type;
 825 }
 826
 827 static string_t parse_string_literals(void)
 828 {
 829         assert(token.type == T_STRING_LITERAL);
 830         string_t result = token.v.string;
 831
 832         next_token();
 833
 834         while (token.type == T_STRING_LITERAL) {
 835                 result = concat_strings(&result, &token.v.string);
 836                 next_token();
 837         }
 838
 839         return result;
 840 }
 841
 842 static void parse_attributes(void)
 843 {
 844         while(true) {
 845                 switch(token.type) {
 846                 case T___attribute__: {
 847                         next_token();
 848
 849                         expect_void('(');
 850                         int depth = 1;
 851                         while(depth > 0) {
 852                                 switch(token.type) {
 853                                 case T_EOF:
 854                                         errorf(HERE, "EOF while parsing attribute");
 855                                         break;
 856                                 case '(':
 857                                         next_token();
 858                                         depth++;
 859                                         break;
 860                                 case ')':
 861                                         next_token();
 862                                         depth--;
 863                                         break;
 864                                 default:
 865                                         next_token();
 866                                 }
 867                         }
 868                         break;
 869                 }
 870                 case T_asm:
 871                         next_token();
 872                         expect_void('(');
 873                         if(token.type != T_STRING_LITERAL) {
 874                                 parse_error_expected("while parsing assembler attribute",
 875                                                      T_STRING_LITERAL);
 876                                 eat_paren();
 877                                 break;
 878                         } else {
 879                                 parse_string_literals();
 880                         }
 881                         expect_void(')');
 882                         break;
 883                 default:
 884                         goto attributes_finished;
 885                 }
 886         }
 887
 888 attributes_finished:
 889         ;
 890 }
 891
 892 static designator_t *parse_designation(void)
 893 {
 894         designator_t *result = NULL;
 895         designator_t *last   = NULL;
 896
 897         while(true) {
 898                 designator_t *designator;
 899                 switch(token.type) {
 900                 case '[':
 901                         designator = allocate_ast_zero(sizeof(designator[0]));
 902                         designator->source_position = token.source_position;
 903                         next_token();
 904                         designator->array_index = parse_constant_expression();
 905                         expect(']');
 906                         break;
 907                 case '.':
 908                         designator = allocate_ast_zero(sizeof(designator[0]));
 909                         designator->source_position = token.source_position;
 910                         next_token();
 911                         if(token.type != T_IDENTIFIER) {
 912                                 parse_error_expected("while parsing designator",
 913                                                      T_IDENTIFIER, 0);
 914                                 return NULL;
 915                         }
 916                         designator->symbol = token.v.symbol;
 917                         next_token();
 918                         break;
 919                 default:
 920                         expect('=');
 921                         return result;
 922                 }
 923
 924                 assert(designator != NULL);
 925                 if(last != NULL) {
 926                         last->next = designator;
 927                 } else {
 928                         result = designator;
 929                 }
 930                 last = designator;
 931         }
 932 }
 933
 934 static initializer_t *initializer_from_string(array_type_t *type,
 935                                               const string_t *const string)
 936 {
 937         /* TODO: check len vs. size of array type */
 938         (void) type;
 939
 940         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
 941         initializer->string.string = *string;
 942
 943         return initializer;
 944 }
 945
 946 static initializer_t *initializer_from_wide_string(array_type_t *const type,
 947                                                    wide_string_t *const string)
 948 {
 949         /* TODO: check len vs. size of array type */
 950         (void) type;
 951
 952         initializer_t *const initializer =
 953                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
 954         initializer->wide_string.string = *string;
 955
 956         return initializer;
 957 }
 958
 959 static initializer_t *initializer_from_expression(type_t *orig_type,
 960                                                   expression_t *expression)
 961 {
 962         /* TODO check that expression is a constant expression */
 963
 964         /* § 6.7.8.14/15 char array may be initialized by string literals */
 965         type_t *type           = skip_typeref(orig_type);
 966         type_t *expr_type_orig = expression->base.type;
 967         type_t *expr_type      = skip_typeref(expr_type_orig);
 968         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
 969                 array_type_t *const array_type   = &type->array;
 970                 type_t       *const element_type = skip_typeref(array_type->element_type);
 971
 972                 if (element_type->kind == TYPE_ATOMIC) {
 973                         atomic_type_kind_t akind = element_type->atomic.akind;
 974                         switch (expression->kind) {
 975                                 case EXPR_STRING_LITERAL:
 976                                         if (akind == ATOMIC_TYPE_CHAR
 977                                                         || akind == ATOMIC_TYPE_SCHAR
 978                                                         || akind == ATOMIC_TYPE_UCHAR) {
 979                                                 return initializer_from_string(array_type,
 980                                                         &expression->string.value);
 981                                         }
 982
 983                                 case EXPR_WIDE_STRING_LITERAL: {
 984                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
 985                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
 986                                                 return initializer_from_wide_string(array_type,
 987                                                         &expression->wide_string.value);
 988                                         }
 989                                 }
 990
 991                                 default:
 992                                         break;
 993                         }
 994                 }
 995         }
 996
 997         type_t *const res_type = semantic_assign(type, expression, "initializer");
 998         if (res_type == NULL)
 999                 return NULL;
1000
1001         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1002         result->value.value = create_implicit_cast(expression, res_type);
1003
1004         return result;
1005 }
1006
1007 static bool is_initializer_constant(const expression_t *expression)
1008 {
1009         return is_constant_expression(expression)
1010                 || is_address_constant(expression);
1011 }
1012
1013 static initializer_t *parse_scalar_initializer(type_t *type,
1014                                                bool must_be_constant)
1015 {
1016         /* there might be extra {} hierarchies */
1017         int braces = 0;
1018         while(token.type == '{') {
1019                 next_token();
1020                 if(braces == 0) {
1021                         warningf(HERE, "extra curly braces around scalar initializer");
1022                 }
1023                 braces++;
1024         }
1025
1026         expression_t *expression = parse_assignment_expression();
1027         if(must_be_constant && !is_initializer_constant(expression)) {
1028                 errorf(expression->base.source_position,
1029                        "Initialisation expression '%E' is not constant\n",
1030                        expression);
1031         }
1032
1033         initializer_t *initializer = initializer_from_expression(type, expression);
1034
1035         if(initializer == NULL) {
1036                 errorf(expression->base.source_position,
1037                        "expression '%E' doesn't match expected type '%T'",
1038                        expression, type);
1039                 /* TODO */
1040                 return NULL;
1041         }
1042
1043         bool additional_warning_displayed = false;
1044         while(braces > 0) {
1045                 if(token.type == ',') {
1046                         next_token();
1047                 }
1048                 if(token.type != '}') {
1049                         if(!additional_warning_displayed) {
1050                                 warningf(HERE, "additional elements in scalar initializer");
1051                                 additional_warning_displayed = true;
1052                         }
1053                 }
1054                 eat_block();
1055                 braces--;
1056         }
1057
1058         return initializer;
1059 }
1060
1061 typedef struct type_path_entry_t type_path_entry_t;
1062 struct type_path_entry_t {
1063         type_t *type;
1064         union {
1065                 size_t         index;
1066                 declaration_t *compound_entry;
1067         } v;
1068 };
1069
1070 typedef struct type_path_t type_path_t;
1071 struct type_path_t {
1072         type_path_entry_t *path;
1073         type_t            *top_type;     /**< type of the element the path points */
1074         size_t             max_index;    /**< largest index in outermost array */
1075         bool               invalid;
1076 };
1077
1078 static __attribute__((unused)) void debug_print_type_path(
1079                 const type_path_t *path)
1080 {
1081         size_t len = ARR_LEN(path->path);
1082
1083         if(path->invalid) {
1084                 fprintf(stderr, "invalid path");
1085                 return;
1086         }
1087
1088         for(size_t i = 0; i < len; ++i) {
1089                 const type_path_entry_t *entry = & path->path[i];
1090
1091                 type_t *type = skip_typeref(entry->type);
1092                 if(is_type_compound(type)) {
1093                         fprintf(stderr, ".%s", entry->v.compound_entry->symbol->string);
1094                 } else if(is_type_array(type)) {
1095                         fprintf(stderr, "[%u]", entry->v.index);
1096                 } else {
1097                         fprintf(stderr, "-INVALID-");
1098                 }
1099         }
1100         fprintf(stderr, "  (");
1101         print_type(path->top_type);
1102         fprintf(stderr, ")");
1103 }
1104
1105 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1106 {
1107         size_t len = ARR_LEN(path->path);
1108         assert(len > 0);
1109         return & path->path[len-1];
1110 }
1111
1112 static type_path_entry_t *append_to_type_path(type_path_t *path)
1113 {
1114         size_t len = ARR_LEN(path->path);
1115         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1116
1117         type_path_entry_t *result = & path->path[len];
1118         memset(result, 0, sizeof(result[0]));
1119         return result;
1120 }
1121
1122 static void descend_into_subtype(type_path_t *path)
1123 {
1124         type_t *orig_top_type = path->top_type;
1125         type_t *top_type      = skip_typeref(orig_top_type);
1126
1127         assert(is_type_compound(top_type) || is_type_array(top_type));
1128
1129         type_path_entry_t *top = append_to_type_path(path);
1130         top->type              = top_type;
1131
1132         if(is_type_compound(top_type)) {
1133                 declaration_t *declaration = top_type->compound.declaration;
1134                 declaration_t *entry       = declaration->scope.declarations;
1135
1136                 top->v.compound_entry = entry;
1137                 path->top_type        = entry->type;
1138         } else {
1139                 assert(is_type_array(top_type));
1140
1141                 top->v.index   = 0;
1142                 path->top_type = top_type->array.element_type;
1143         }
1144 }
1145
1146 static void ascend_from_subtype(type_path_t *path)
1147 {
1148         type_path_entry_t *top = get_type_path_top(path);
1149
1150         path->top_type = top->type;
1151
1152         size_t len = ARR_LEN(path->path);
1153         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1154 }
1155
1156 static void ascend_to(type_path_t *path, size_t top_path_level)
1157 {
1158         size_t len = ARR_LEN(path->path);
1159         assert(len >= top_path_level);
1160
1161         while(len > top_path_level) {
1162                 ascend_from_subtype(path);
1163                 len = ARR_LEN(path->path);
1164         }
1165 }
1166
1167 static bool walk_designator(type_path_t *path, const designator_t *designator,
1168                             bool used_in_offsetof)
1169 {
1170         for( ; designator != NULL; designator = designator->next) {
1171                 type_path_entry_t *top       = get_type_path_top(path);
1172                 type_t            *orig_type = top->type;
1173
1174                 type_t *type = skip_typeref(orig_type);
1175
1176                 if(designator->symbol != NULL) {
1177                         symbol_t *symbol = designator->symbol;
1178                         if(!is_type_compound(type)) {
1179                                 if(is_type_valid(type)) {
1180                                         errorf(designator->source_position,
1181                                                "'.%Y' designator used for non-compound type '%T'",
1182                                                symbol, orig_type);
1183                                 }
1184                                 goto failed;
1185                         }
1186
1187                         declaration_t *declaration = type->compound.declaration;
1188                         declaration_t *iter        = declaration->scope.declarations;
1189                         for( ; iter != NULL; iter = iter->next) {
1190                                 if(iter->symbol == symbol) {
1191                                         break;
1192                                 }
1193                         }
1194                         if(iter == NULL) {
1195                                 errorf(designator->source_position,
1196                                        "'%T' has no member named '%Y'", orig_type, symbol);
1197                                 goto failed;
1198                         }
1199                         if(used_in_offsetof) {
1200                                 type_t *real_type = skip_typeref(iter->type);
1201                                 if(real_type->kind == TYPE_BITFIELD) {
1202                                         errorf(designator->source_position,
1203                                                "offsetof designator '%Y' may not specify bitfield",
1204                                                symbol);
1205                                         goto failed;
1206                                 }
1207                         }
1208
1209                         top->type             = orig_type;
1210                         top->v.compound_entry = iter;
1211                         orig_type             = iter->type;
1212                 } else {
1213                         expression_t *array_index = designator->array_index;
1214                         assert(designator->array_index != NULL);
1215
1216                         if(!is_type_array(type)) {
1217                                 if(is_type_valid(type)) {
1218                                         errorf(designator->source_position,
1219                                                "[%E] designator used for non-array type '%T'",
1220                                                array_index, orig_type);
1221                                 }
1222                                 goto failed;
1223                         }
1224                         if(!is_type_valid(array_index->base.type)) {
1225                                 goto failed;
1226                         }
1227
1228                         long index = fold_constant(array_index);
1229                         if(!used_in_offsetof) {
1230                                 if(index < 0) {
1231                                         errorf(designator->source_position,
1232                                                "array index [%E] must be positive", array_index);
1233                                         goto failed;
1234                                 }
1235                                 if(type->array.size_constant == true) {
1236                                         long array_size = type->array.size;
1237                                         if(index >= array_size) {
1238                                                 errorf(designator->source_position,
1239                                                                 "designator [%E] (%d) exceeds array size %d",
1240                                                                 array_index, index, array_size);
1241                                                 goto failed;
1242                                         }
1243                                 }
1244                         }
1245
1246                         top->type    = orig_type;
1247                         top->v.index = (size_t) index;
1248                         orig_type    = type->array.element_type;
1249                 }
1250                 path->top_type = orig_type;
1251
1252                 if(designator->next != NULL) {
1253                         descend_into_subtype(path);
1254                 }
1255         }
1256
1257         path->invalid  = false;
1258         return true;
1259
1260 failed:
1261         return false;
1262 }
1263
1264 static void advance_current_object(type_path_t *path, size_t top_path_level)
1265 {
1266         if(path->invalid)
1267                 return;
1268
1269         type_path_entry_t *top = get_type_path_top(path);
1270
1271         type_t *type = skip_typeref(top->type);
1272         if(is_type_union(type)) {
1273                 /* in unions only the first element is initialized */
1274                 top->v.compound_entry = NULL;
1275         } else if(is_type_struct(type)) {
1276                 declaration_t *entry = top->v.compound_entry;
1277
1278                 entry                 = entry->next;
1279                 top->v.compound_entry = entry;
1280                 if(entry != NULL) {
1281                         path->top_type = entry->type;
1282                         return;
1283                 }
1284         } else {
1285                 assert(is_type_array(type));
1286
1287                 top->v.index++;
1288
1289                 if(!type->array.size_constant || top->v.index < type->array.size) {
1290                         return;
1291                 }
1292         }
1293
1294         /* we're past the last member of the current sub-aggregate, try if we
1295          * can ascend in the type hierarchy and continue with another subobject */
1296         size_t len = ARR_LEN(path->path);
1297
1298         if(len > top_path_level) {
1299                 ascend_from_subtype(path);
1300                 advance_current_object(path, top_path_level);
1301         } else {
1302                 path->invalid = true;
1303         }
1304 }
1305
1306 static void skip_initializers(void)
1307 {
1308         if(token.type == '{')
1309                 next_token();
1310
1311         while(token.type != '}') {
1312                 if(token.type == T_EOF)
1313                         return;
1314                 if(token.type == '{') {
1315                         eat_block();
1316                         continue;
1317                 }
1318                 next_token();
1319         }
1320 }
1321
1322 static initializer_t *parse_sub_initializer(type_path_t *path,
1323                 type_t *outer_type, size_t top_path_level, bool must_be_constant)
1324 {
1325         type_t *orig_type = path->top_type;
1326         type_t *type      = skip_typeref(orig_type);
1327
1328         /* we can't do usefull stuff if we didn't even parse the type. Skip the
1329          * initializers in this case. */
1330         if(!is_type_valid(type)) {
1331                 skip_initializers();
1332                 return NULL;
1333         }
1334
1335         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1336
1337         while(true) {
1338                 designator_t *designator = NULL;
1339                 if(token.type == '.' || token.type == '[') {
1340                         designator = parse_designation();
1341
1342                         /* reset path to toplevel, evaluate designator from there */
1343                         ascend_to(path, top_path_level);
1344                         if(!walk_designator(path, designator, false)) {
1345                                 /* can't continue after designation error */
1346                                 goto end_error;
1347                         }
1348
1349                         initializer_t *designator_initializer
1350                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1351                         designator_initializer->designator.designator = designator;
1352                         ARR_APP1(initializer_t*, initializers, designator_initializer);
1353                 }
1354
1355                 initializer_t *sub;
1356
1357                 if(token.type == '{') {
1358                         if(is_type_scalar(type)) {
1359                                 sub = parse_scalar_initializer(type, must_be_constant);
1360                         } else {
1361                                 eat('{');
1362                                 descend_into_subtype(path);
1363
1364                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
1365                                                             must_be_constant);
1366
1367                                 ascend_from_subtype(path);
1368
1369                                 expect_block('}');
1370                         }
1371                 } else {
1372                         /* must be an expression */
1373                         expression_t *expression = parse_assignment_expression();
1374
1375                         if(must_be_constant && !is_initializer_constant(expression)) {
1376                                 errorf(expression->base.source_position,
1377                                        "Initialisation expression '%E' is not constant\n",
1378                                        expression);
1379                         }
1380
1381                         /* handle { "string" } special case */
1382                         if((expression->kind == EXPR_STRING_LITERAL
1383                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
1384                                         && outer_type != NULL) {
1385                                 sub = initializer_from_expression(outer_type, expression);
1386                                 if(sub != NULL) {
1387                                         if(token.type == ',') {
1388                                                 next_token();
1389                                         }
1390                                         if(token.type != '}') {
1391                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
1392                                                                  orig_type);
1393                                         }
1394                                         /* TODO: eat , ... */
1395                                         return sub;
1396                                 }
1397                         }
1398
1399                         /* descend into subtypes until expression matches type */
1400                         while(true) {
1401                                 orig_type = path->top_type;
1402                                 type      = skip_typeref(orig_type);
1403
1404                                 sub = initializer_from_expression(orig_type, expression);
1405                                 if(sub != NULL) {
1406                                         break;
1407                                 }
1408                                 if(!is_type_valid(type)) {
1409                                         goto end_error;
1410                                 }
1411                                 if(is_type_scalar(type)) {
1412                                         errorf(expression->base.source_position,
1413                                                         "expression '%E' doesn't match expected type '%T'",
1414                                                         expression, orig_type);
1415                                         goto end_error;
1416                                 }
1417
1418                                 descend_into_subtype(path);
1419                         }
1420                 }
1421
1422                 /* update largest index of top array */
1423                 const type_path_entry_t *first      = &path->path[0];
1424                 type_t                  *first_type = first->type;
1425                 first_type                          = skip_typeref(first_type);
1426                 if(is_type_array(first_type)) {
1427                         size_t index = first->v.index;
1428                         if(index > path->max_index)
1429                                 path->max_index = index;
1430                 }
1431
1432                 /* append to initializers list */
1433                 ARR_APP1(initializer_t*, initializers, sub);
1434
1435                 if(token.type == '}') {
1436                         break;
1437                 }
1438                 expect(',');
1439                 if(token.type == '}') {
1440                         break;
1441                 }
1442
1443                 advance_current_object(path, top_path_level);
1444                 orig_type = path->top_type;
1445                 type      = skip_typeref(orig_type);
1446         }
1447
1448         size_t len  = ARR_LEN(initializers);
1449         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
1450         initializer_t *result = allocate_ast_zero(size);
1451         result->kind          = INITIALIZER_LIST;
1452         result->list.len      = len;
1453         memcpy(&result->list.initializers, initializers,
1454                len * sizeof(initializers[0]));
1455
1456         ascend_to(path, top_path_level);
1457
1458         return result;
1459
1460 end_error:
1461         skip_initializers();
1462         DEL_ARR_F(initializers);
1463         ascend_to(path, top_path_level);
1464         return NULL;
1465 }
1466
1467 typedef struct parse_initializer_env_t {
1468         type_t        *type;        /* the type of the initializer. In case of an
1469                                        array type with unspecified size this gets
1470                                        adjusted to the actual size. */
1471         initializer_t *initializer; /* initializer will be filled in here */
1472         bool           must_be_constant;
1473 } parse_initializer_env_t;
1474
1475 static void parse_initializer(parse_initializer_env_t *env)
1476 {
1477         type_t        *type   = skip_typeref(env->type);
1478         initializer_t *result = NULL;
1479         size_t         max_index;
1480
1481         if(is_type_scalar(type)) {
1482                 /* TODO: § 6.7.8.11; eat {} without warning */
1483                 result = parse_scalar_initializer(type, env->must_be_constant);
1484         } else if(token.type == '{') {
1485                 eat('{');
1486
1487                 type_path_t path;
1488                 memset(&path, 0, sizeof(path));
1489                 path.top_type = env->type;
1490                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
1491
1492                 descend_into_subtype(&path);
1493
1494                 result = parse_sub_initializer(&path, env->type, 1,
1495                                                env->must_be_constant);
1496
1497                 max_index = path.max_index;
1498                 DEL_ARR_F(path.path);
1499
1500                 expect_void('}');
1501         } else {
1502                 /* parse_scalar_initializer also works in this case: we simply
1503                  * have an expression without {} around it */
1504                 result = parse_scalar_initializer(type, env->must_be_constant);
1505         }
1506
1507         /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
1508          * the array type size */
1509         if(is_type_array(type) && type->array.size_expression == NULL
1510                         && result != NULL) {
1511                 size_t size;
1512                 switch (result->kind) {
1513                 case INITIALIZER_LIST:
1514                         size = max_index + 1;
1515                         break;
1516
1517                 case INITIALIZER_STRING:
1518                         size = result->string.string.size;
1519                         break;
1520
1521                 case INITIALIZER_WIDE_STRING:
1522                         size = result->wide_string.string.size;
1523                         break;
1524
1525                 default:
1526                         panic("invalid initializer type");
1527                 }
1528
1529                 expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
1530                 cnst->base.type          = type_size_t;
1531                 cnst->conste.v.int_value = size;
1532
1533                 type_t *new_type = duplicate_type(type);
1534
1535                 new_type->array.size_expression = cnst;
1536                 new_type->array.size_constant   = true;
1537                 new_type->array.size            = size;
1538                 env->type = new_type;
1539         }
1540
1541         env->initializer = result;
1542 }
1543
1544 static declaration_t *append_declaration(declaration_t *declaration);
1545
1546 static declaration_t *parse_compound_type_specifier(bool is_struct)
1547 {
1548         if(is_struct) {
1549                 eat(T_struct);
1550         } else {
1551                 eat(T_union);
1552         }
1553
1554         symbol_t      *symbol      = NULL;
1555         declaration_t *declaration = NULL;
1556
1557         if (token.type == T___attribute__) {
1558                 /* TODO */
1559                 parse_attributes();
1560         }
1561
1562         if(token.type == T_IDENTIFIER) {
1563                 symbol = token.v.symbol;
1564                 next_token();
1565
1566                 if(is_struct) {
1567                         declaration = get_declaration(symbol, NAMESPACE_STRUCT);
1568                 } else {
1569                         declaration = get_declaration(symbol, NAMESPACE_UNION);
1570                 }
1571         } else if(token.type != '{') {
1572                 if(is_struct) {
1573                         parse_error_expected("while parsing struct type specifier",
1574                                              T_IDENTIFIER, '{', 0);
1575                 } else {
1576                         parse_error_expected("while parsing union type specifier",
1577                                              T_IDENTIFIER, '{', 0);
1578                 }
1579
1580                 return NULL;
1581         }
1582
1583         if(declaration == NULL) {
1584                 declaration = allocate_declaration_zero();
1585                 declaration->namespc         =
1586                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
1587                 declaration->source_position = token.source_position;
1588                 declaration->symbol          = symbol;
1589                 declaration->parent_scope  = scope;
1590                 if (symbol != NULL) {
1591                         environment_push(declaration);
1592                 }
1593                 append_declaration(declaration);
1594         }
1595
1596         if(token.type == '{') {
1597                 if(declaration->init.is_defined) {
1598                         assert(symbol != NULL);
1599                         errorf(HERE, "multiple definitions of '%s %Y'",
1600                                is_struct ? "struct" : "union", symbol);
1601                         declaration->scope.declarations = NULL;
1602                 }
1603                 declaration->init.is_defined = true;
1604
1605                 parse_compound_type_entries(declaration);
1606                 parse_attributes();
1607         }
1608
1609         return declaration;
1610 }
1611
1612 static void parse_enum_entries(type_t *const enum_type)
1613 {
1614         eat('{');
1615
1616         if(token.type == '}') {
1617                 next_token();
1618                 errorf(HERE, "empty enum not allowed");
1619                 return;
1620         }
1621
1622         do {
1623                 if(token.type != T_IDENTIFIER) {
1624                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, 0);
1625                         eat_block();
1626                         return;
1627                 }
1628
1629                 declaration_t *const entry = allocate_declaration_zero();
1630                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
1631                 entry->type            = enum_type;
1632                 entry->symbol          = token.v.symbol;
1633                 entry->source_position = token.source_position;
1634                 next_token();
1635
1636                 if(token.type == '=') {
1637                         next_token();
1638                         expression_t *value = parse_constant_expression();
1639
1640                         value = create_implicit_cast(value, enum_type);
1641                         entry->init.enum_value = value;
1642
1643                         /* TODO semantic */
1644                 }
1645
1646                 record_declaration(entry);
1647
1648                 if(token.type != ',')
1649                         break;
1650                 next_token();
1651         } while(token.type != '}');
1652
1653         expect_void('}');
1654 }
1655
1656 static type_t *parse_enum_specifier(void)
1657 {
1658         eat(T_enum);
1659
1660         declaration_t *declaration;
1661         symbol_t      *symbol;
1662
1663         if(token.type == T_IDENTIFIER) {
1664                 symbol = token.v.symbol;
1665                 next_token();
1666
1667                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1668         } else if(token.type != '{') {
1669                 parse_error_expected("while parsing enum type specifier",
1670                                      T_IDENTIFIER, '{', 0);
1671                 return NULL;
1672         } else {
1673                 declaration = NULL;
1674                 symbol      = NULL;
1675         }
1676
1677         if(declaration == NULL) {
1678                 declaration = allocate_declaration_zero();
1679                 declaration->namespc         = NAMESPACE_ENUM;
1680                 declaration->source_position = token.source_position;
1681                 declaration->symbol          = symbol;
1682                 declaration->parent_scope  = scope;
1683         }
1684
1685         type_t *const type      = allocate_type_zero(TYPE_ENUM, declaration->source_position);
1686         type->enumt.declaration = declaration;
1687
1688         if(token.type == '{') {
1689                 if(declaration->init.is_defined) {
1690                         errorf(HERE, "multiple definitions of enum %Y", symbol);
1691                 }
1692                 if (symbol != NULL) {
1693                         environment_push(declaration);
1694                 }
1695                 append_declaration(declaration);
1696                 declaration->init.is_defined = 1;
1697
1698                 parse_enum_entries(type);
1699                 parse_attributes();
1700         }
1701
1702         return type;
1703 }
1704
1705 /**
1706  * if a symbol is a typedef to another type, return true
1707  */
1708 static bool is_typedef_symbol(symbol_t *symbol)
1709 {
1710         const declaration_t *const declaration =
1711                 get_declaration(symbol, NAMESPACE_NORMAL);
1712         return
1713                 declaration != NULL &&
1714                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1715 }
1716
1717 static type_t *parse_typeof(void)
1718 {
1719         eat(T___typeof__);
1720
1721         type_t *type;
1722
1723         expect('(');
1724
1725         expression_t *expression  = NULL;
1726
1727 restart:
1728         switch(token.type) {
1729         case T___extension__:
1730                 /* this can be a prefix to a typename or an expression */
1731                 /* we simply eat it now. */
1732                 do {
1733                         next_token();
1734                 } while(token.type == T___extension__);
1735                 goto restart;
1736
1737         case T_IDENTIFIER:
1738                 if(is_typedef_symbol(token.v.symbol)) {
1739                         type = parse_typename();
1740                 } else {
1741                         expression = parse_expression();
1742                         type       = expression->base.type;
1743                 }
1744                 break;
1745
1746         TYPENAME_START
1747                 type = parse_typename();
1748                 break;
1749
1750         default:
1751                 expression = parse_expression();
1752                 type       = expression->base.type;
1753                 break;
1754         }
1755
1756         expect(')');
1757
1758         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF, expression->base.source_position);
1759         typeof_type->typeoft.expression  = expression;
1760         typeof_type->typeoft.typeof_type = type;
1761
1762         return typeof_type;
1763 }
1764
1765 typedef enum {
1766         SPECIFIER_SIGNED    = 1 << 0,
1767         SPECIFIER_UNSIGNED  = 1 << 1,
1768         SPECIFIER_LONG      = 1 << 2,
1769         SPECIFIER_INT       = 1 << 3,
1770         SPECIFIER_DOUBLE    = 1 << 4,
1771         SPECIFIER_CHAR      = 1 << 5,
1772         SPECIFIER_SHORT     = 1 << 6,
1773         SPECIFIER_LONG_LONG = 1 << 7,
1774         SPECIFIER_FLOAT     = 1 << 8,
1775         SPECIFIER_BOOL      = 1 << 9,
1776         SPECIFIER_VOID      = 1 << 10,
1777 #ifdef PROVIDE_COMPLEX
1778         SPECIFIER_COMPLEX   = 1 << 11,
1779         SPECIFIER_IMAGINARY = 1 << 12,
1780 #endif
1781 } specifiers_t;
1782
1783 static type_t *create_builtin_type(symbol_t *const symbol,
1784                                    type_t *const real_type)
1785 {
1786         type_t *type            = allocate_type_zero(TYPE_BUILTIN, builtin_source_position);
1787         type->builtin.symbol    = symbol;
1788         type->builtin.real_type = real_type;
1789
1790         type_t *result = typehash_insert(type);
1791         if (type != result) {
1792                 free_type(type);
1793         }
1794
1795         return result;
1796 }
1797
1798 static type_t *get_typedef_type(symbol_t *symbol)
1799 {
1800         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1801         if(declaration == NULL
1802                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1803                 return NULL;
1804
1805         type_t *type               = allocate_type_zero(TYPE_TYPEDEF, declaration->source_position);
1806         type->typedeft.declaration = declaration;
1807
1808         return type;
1809 }
1810
1811 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1812 {
1813         type_t   *type            = NULL;
1814         unsigned  type_qualifiers = 0;
1815         unsigned  type_specifiers = 0;
1816         int       newtype         = 0;
1817
1818         specifiers->source_position = token.source_position;
1819
1820         while(true) {
1821                 switch(token.type) {
1822
1823                 /* storage class */
1824 #define MATCH_STORAGE_CLASS(token, class)                                  \
1825                 case token:                                                        \
1826                         if(specifiers->declared_storage_class != STORAGE_CLASS_NONE) { \
1827                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
1828                         }                                                              \
1829                         specifiers->declared_storage_class = class;                    \
1830                         next_token();                                                  \
1831                         break;
1832
1833                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1834                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1835                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1836                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1837                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1838
1839                 case T___thread:
1840                         switch (specifiers->declared_storage_class) {
1841                         case STORAGE_CLASS_NONE:
1842                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD;
1843                                 break;
1844
1845                         case STORAGE_CLASS_EXTERN:
1846                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD_EXTERN;
1847                                 break;
1848
1849                         case STORAGE_CLASS_STATIC:
1850                                 specifiers->declared_storage_class = STORAGE_CLASS_THREAD_STATIC;
1851                                 break;
1852
1853                         default:
1854                                 errorf(HERE, "multiple storage classes in declaration specifiers");
1855                                 break;
1856                         }
1857                         next_token();
1858                         break;
1859
1860                 /* type qualifiers */
1861 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1862                 case token:                                                     \
1863                         type_qualifiers |= qualifier;                               \
1864                         next_token();                                               \
1865                         break;
1866
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                 case T___extension__:
1872                         /* TODO */
1873                         next_token();
1874                         break;
1875
1876                 /* type specifiers */
1877 #define MATCH_SPECIFIER(token, specifier, name)                         \
1878                 case token:                                                     \
1879                         next_token();                                               \
1880                         if(type_specifiers & specifier) {                           \
1881                                 errorf(HERE, "multiple " name " type specifiers given"); \
1882                         } else {                                                    \
1883                                 type_specifiers |= specifier;                           \
1884                         }                                                           \
1885                         break;
1886
1887                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
1888                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
1889                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
1890                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
1891                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
1892                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
1893                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
1894                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
1895                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
1896 #ifdef PROVIDE_COMPLEX
1897                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
1898                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
1899 #endif
1900                 case T_forceinline:
1901                         /* only in microsoft mode */
1902                         specifiers->decl_modifiers |= DM_FORCEINLINE;
1903
1904                 case T_inline:
1905                         next_token();
1906                         specifiers->is_inline = true;
1907                         break;
1908
1909                 case T_long:
1910                         next_token();
1911                         if(type_specifiers & SPECIFIER_LONG_LONG) {
1912                                 errorf(HERE, "multiple type specifiers given");
1913                         } else if(type_specifiers & SPECIFIER_LONG) {
1914                                 type_specifiers |= SPECIFIER_LONG_LONG;
1915                         } else {
1916                                 type_specifiers |= SPECIFIER_LONG;
1917                         }
1918                         break;
1919
1920                 case T_struct: {
1921                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT, HERE);
1922
1923                         type->compound.declaration = parse_compound_type_specifier(true);
1924                         break;
1925                 }
1926                 case T_union: {
1927                         type = allocate_type_zero(TYPE_COMPOUND_UNION, HERE);
1928
1929                         type->compound.declaration = parse_compound_type_specifier(false);
1930                         break;
1931                 }
1932                 case T_enum:
1933                         type = parse_enum_specifier();
1934                         break;
1935                 case T___typeof__:
1936                         type = parse_typeof();
1937                         break;
1938                 case T___builtin_va_list:
1939                         type = duplicate_type(type_valist);
1940                         next_token();
1941                         break;
1942
1943                 case T___attribute__:
1944                         parse_attributes();
1945                         break;
1946
1947                 case T_IDENTIFIER: {
1948                         /* only parse identifier if we haven't found a type yet */
1949                         if(type != NULL || type_specifiers != 0)
1950                                 goto finish_specifiers;
1951
1952                         type_t *typedef_type = get_typedef_type(token.v.symbol);
1953
1954                         if(typedef_type == NULL)
1955                                 goto finish_specifiers;
1956
1957                         next_token();
1958                         type = typedef_type;
1959                         break;
1960                 }
1961
1962                 /* function specifier */
1963                 default:
1964                         goto finish_specifiers;
1965                 }
1966         }
1967
1968 finish_specifiers:
1969
1970         if(type == NULL) {
1971                 atomic_type_kind_t atomic_type;
1972
1973                 /* match valid basic types */
1974                 switch(type_specifiers) {
1975                 case SPECIFIER_VOID:
1976                         atomic_type = ATOMIC_TYPE_VOID;
1977                         break;
1978                 case SPECIFIER_CHAR:
1979                         atomic_type = ATOMIC_TYPE_CHAR;
1980                         break;
1981                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
1982                         atomic_type = ATOMIC_TYPE_SCHAR;
1983                         break;
1984                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
1985                         atomic_type = ATOMIC_TYPE_UCHAR;
1986                         break;
1987                 case SPECIFIER_SHORT:
1988                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
1989                 case SPECIFIER_SHORT | SPECIFIER_INT:
1990                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1991                         atomic_type = ATOMIC_TYPE_SHORT;
1992                         break;
1993                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
1994                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1995                         atomic_type = ATOMIC_TYPE_USHORT;
1996                         break;
1997                 case SPECIFIER_INT:
1998                 case SPECIFIER_SIGNED:
1999                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2000                         atomic_type = ATOMIC_TYPE_INT;
2001                         break;
2002                 case SPECIFIER_UNSIGNED:
2003                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2004                         atomic_type = ATOMIC_TYPE_UINT;
2005                         break;
2006                 case SPECIFIER_LONG:
2007                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2008                 case SPECIFIER_LONG | SPECIFIER_INT:
2009                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2010                         atomic_type = ATOMIC_TYPE_LONG;
2011                         break;
2012                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2013                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2014                         atomic_type = ATOMIC_TYPE_ULONG;
2015                         break;
2016                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2017                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2018                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2019                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2020                         | SPECIFIER_INT:
2021                         atomic_type = ATOMIC_TYPE_LONGLONG;
2022                         break;
2023                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2024                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2025                         | SPECIFIER_INT:
2026                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2027                         break;
2028                 case SPECIFIER_FLOAT:
2029                         atomic_type = ATOMIC_TYPE_FLOAT;
2030                         break;
2031                 case SPECIFIER_DOUBLE:
2032                         atomic_type = ATOMIC_TYPE_DOUBLE;
2033                         break;
2034                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2035                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2036                         break;
2037                 case SPECIFIER_BOOL:
2038                         atomic_type = ATOMIC_TYPE_BOOL;
2039                         break;
2040 #ifdef PROVIDE_COMPLEX
2041                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2042                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
2043                         break;
2044                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2045                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
2046                         break;
2047                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2048                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
2049                         break;
2050                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2051                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
2052                         break;
2053                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2054                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
2055                         break;
2056                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2057                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
2058                         break;
2059 #endif
2060                 default:
2061                         /* invalid specifier combination, give an error message */
2062                         if(type_specifiers == 0) {
2063                                 if (! strict_mode) {
2064                                         if (warning.implicit_int) {
2065                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
2066                                         }
2067                                         atomic_type = ATOMIC_TYPE_INT;
2068                                         break;
2069                                 } else {
2070                                         errorf(HERE, "no type specifiers given in declaration");
2071                                 }
2072                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
2073                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
2074                                 errorf(HERE, "signed and unsigned specifiers gives");
2075                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
2076                                 errorf(HERE, "only integer types can be signed or unsigned");
2077                         } else {
2078                                 errorf(HERE, "multiple datatypes in declaration");
2079                         }
2080                         atomic_type = ATOMIC_TYPE_INVALID;
2081                 }
2082
2083                 type               = allocate_type_zero(TYPE_ATOMIC, builtin_source_position);
2084                 type->atomic.akind = atomic_type;
2085                 newtype            = 1;
2086         } else {
2087                 if(type_specifiers != 0) {
2088                         errorf(HERE, "multiple datatypes in declaration");
2089                 }
2090         }
2091
2092         type->base.qualifiers = type_qualifiers;
2093
2094         type_t *result = typehash_insert(type);
2095         if(newtype && result != type) {
2096                 free_type(type);
2097         }
2098
2099         specifiers->type = result;
2100 }
2101
2102 static type_qualifiers_t parse_type_qualifiers(void)
2103 {
2104         type_qualifiers_t type_qualifiers = TYPE_QUALIFIER_NONE;
2105
2106         while(true) {
2107                 switch(token.type) {
2108                 /* type qualifiers */
2109                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2110                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2111                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2112
2113                 default:
2114                         return type_qualifiers;
2115                 }
2116         }
2117 }
2118
2119 static declaration_t *parse_identifier_list(void)
2120 {
2121         declaration_t *declarations     = NULL;
2122         declaration_t *last_declaration = NULL;
2123         do {
2124                 declaration_t *const declaration = allocate_declaration_zero();
2125                 declaration->type            = NULL; /* a K&R parameter list has no types, yet */
2126                 declaration->source_position = token.source_position;
2127                 declaration->symbol          = token.v.symbol;
2128                 next_token();
2129
2130                 if(last_declaration != NULL) {
2131                         last_declaration->next = declaration;
2132                 } else {
2133                         declarations = declaration;
2134                 }
2135                 last_declaration = declaration;
2136
2137                 if(token.type != ',')
2138                         break;
2139                 next_token();
2140         } while(token.type == T_IDENTIFIER);
2141
2142         return declarations;
2143 }
2144
2145 static void semantic_parameter(declaration_t *declaration)
2146 {
2147         /* TODO: improve error messages */
2148
2149         if(declaration->declared_storage_class == STORAGE_CLASS_TYPEDEF) {
2150                 errorf(HERE, "typedef not allowed in parameter list");
2151         } else if(declaration->declared_storage_class != STORAGE_CLASS_NONE
2152                         && declaration->declared_storage_class != STORAGE_CLASS_REGISTER) {
2153                 errorf(HERE, "parameter may only have none or register storage class");
2154         }
2155
2156         type_t *const orig_type = declaration->type;
2157         type_t *      type      = skip_typeref(orig_type);
2158
2159         /* Array as last part of a parameter type is just syntactic sugar.  Turn it
2160          * into a pointer. § 6.7.5.3 (7) */
2161         if (is_type_array(type)) {
2162                 type_t *const element_type = type->array.element_type;
2163
2164                 type = make_pointer_type(element_type, type->base.qualifiers);
2165
2166                 declaration->type = type;
2167         }
2168
2169         if(is_type_incomplete(type)) {
2170                 errorf(HERE, "incomplete type '%T' not allowed for parameter '%Y'",
2171                        orig_type, declaration->symbol);
2172         }
2173 }
2174
2175 static declaration_t *parse_parameter(void)
2176 {
2177         declaration_specifiers_t specifiers;
2178         memset(&specifiers, 0, sizeof(specifiers));
2179
2180         parse_declaration_specifiers(&specifiers);
2181
2182         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
2183
2184         semantic_parameter(declaration);
2185
2186         return declaration;
2187 }
2188
2189 static declaration_t *parse_parameters(function_type_t *type)
2190 {
2191         if(token.type == T_IDENTIFIER) {
2192                 symbol_t *symbol = token.v.symbol;
2193                 if(!is_typedef_symbol(symbol)) {
2194                         type->kr_style_parameters = true;
2195                         return parse_identifier_list();
2196                 }
2197         }
2198
2199         if(token.type == ')') {
2200                 type->unspecified_parameters = 1;
2201                 return NULL;
2202         }
2203         if(token.type == T_void && look_ahead(1)->type == ')') {
2204                 next_token();
2205                 return NULL;
2206         }
2207
2208         declaration_t        *declarations = NULL;
2209         declaration_t        *declaration;
2210         declaration_t        *last_declaration = NULL;
2211         function_parameter_t *parameter;
2212         function_parameter_t *last_parameter = NULL;
2213
2214         while(true) {
2215                 switch(token.type) {
2216                 case T_DOTDOTDOT:
2217                         next_token();
2218                         type->variadic = 1;
2219                         return declarations;
2220
2221                 case T_IDENTIFIER:
2222                 case T___extension__:
2223                 DECLARATION_START
2224                         declaration = parse_parameter();
2225
2226                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
2227                         memset(parameter, 0, sizeof(parameter[0]));
2228                         parameter->type = declaration->type;
2229
2230                         if(last_parameter != NULL) {
2231                                 last_declaration->next = declaration;
2232                                 last_parameter->next   = parameter;
2233                         } else {
2234                                 type->parameters = parameter;
2235                                 declarations     = declaration;
2236                         }
2237                         last_parameter   = parameter;
2238                         last_declaration = declaration;
2239                         break;
2240
2241                 default:
2242                         return declarations;
2243                 }
2244                 if(token.type != ',')
2245                         return declarations;
2246                 next_token();
2247         }
2248 }
2249
2250 typedef enum {
2251         CONSTRUCT_INVALID,
2252         CONSTRUCT_POINTER,
2253         CONSTRUCT_FUNCTION,
2254         CONSTRUCT_ARRAY
2255 } construct_type_kind_t;
2256
2257 typedef struct construct_type_t construct_type_t;
2258 struct construct_type_t {
2259         construct_type_kind_t  kind;
2260         construct_type_t      *next;
2261 };
2262
2263 typedef struct parsed_pointer_t parsed_pointer_t;
2264 struct parsed_pointer_t {
2265         construct_type_t  construct_type;
2266         type_qualifiers_t type_qualifiers;
2267 };
2268
2269 typedef struct construct_function_type_t construct_function_type_t;
2270 struct construct_function_type_t {
2271         construct_type_t  construct_type;
2272         type_t           *function_type;
2273 };
2274
2275 typedef struct parsed_array_t parsed_array_t;
2276 struct parsed_array_t {
2277         construct_type_t  construct_type;
2278         type_qualifiers_t type_qualifiers;
2279         bool              is_static;
2280         bool              is_variable;
2281         expression_t     *size;
2282 };
2283
2284 typedef struct construct_base_type_t construct_base_type_t;
2285 struct construct_base_type_t {
2286         construct_type_t  construct_type;
2287         type_t           *type;
2288 };
2289
2290 static construct_type_t *parse_pointer_declarator(void)
2291 {
2292         eat('*');
2293
2294         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
2295         memset(pointer, 0, sizeof(pointer[0]));
2296         pointer->construct_type.kind = CONSTRUCT_POINTER;
2297         pointer->type_qualifiers     = parse_type_qualifiers();
2298
2299         return (construct_type_t*) pointer;
2300 }
2301
2302 static construct_type_t *parse_array_declarator(void)
2303 {
2304         eat('[');
2305
2306         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
2307         memset(array, 0, sizeof(array[0]));
2308         array->construct_type.kind = CONSTRUCT_ARRAY;
2309
2310         if(token.type == T_static) {
2311                 array->is_static = true;
2312                 next_token();
2313         }
2314
2315         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
2316         if(type_qualifiers != 0) {
2317                 if(token.type == T_static) {
2318                         array->is_static = true;
2319                         next_token();
2320                 }
2321         }
2322         array->type_qualifiers = type_qualifiers;
2323
2324         if(token.type == '*' && look_ahead(1)->type == ']') {
2325                 array->is_variable = true;
2326                 next_token();
2327         } else if(token.type != ']') {
2328                 array->size = parse_assignment_expression();
2329         }
2330
2331         expect(']');
2332
2333         return (construct_type_t*) array;
2334 }
2335
2336 static construct_type_t *parse_function_declarator(declaration_t *declaration)
2337 {
2338         eat('(');
2339
2340         type_t *type;
2341         if(declaration != NULL) {
2342                 type = allocate_type_zero(TYPE_FUNCTION, declaration->source_position);
2343         } else {
2344                 type = allocate_type_zero(TYPE_FUNCTION, token.source_position);
2345         }
2346
2347         declaration_t *parameters = parse_parameters(&type->function);
2348         if(declaration != NULL) {
2349                 declaration->scope.declarations = parameters;
2350         }
2351
2352         construct_function_type_t *construct_function_type =
2353                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
2354         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
2355         construct_function_type->construct_type.kind = CONSTRUCT_FUNCTION;
2356         construct_function_type->function_type       = type;
2357
2358         expect(')');
2359
2360         return (construct_type_t*) construct_function_type;
2361 }
2362
2363 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
2364                 bool may_be_abstract)
2365 {
2366         /* construct a single linked list of construct_type_t's which describe
2367          * how to construct the final declarator type */
2368         construct_type_t *first = NULL;
2369         construct_type_t *last  = NULL;
2370
2371         /* pointers */
2372         while(token.type == '*') {
2373                 construct_type_t *type = parse_pointer_declarator();
2374
2375                 if(last == NULL) {
2376                         first = type;
2377                         last  = type;
2378                 } else {
2379                         last->next = type;
2380                         last       = type;
2381                 }
2382         }
2383
2384         /* TODO: find out if this is correct */
2385         parse_attributes();
2386
2387         construct_type_t *inner_types = NULL;
2388
2389         switch(token.type) {
2390         case T_IDENTIFIER:
2391                 if(declaration == NULL) {
2392                         errorf(HERE, "no identifier expected in typename");
2393                 } else {
2394                         declaration->symbol          = token.v.symbol;
2395                         declaration->source_position = token.source_position;
2396                 }
2397                 next_token();
2398                 break;
2399         case '(':
2400                 next_token();
2401                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
2402                 expect(')');
2403                 break;
2404         default:
2405                 if(may_be_abstract)
2406                         break;
2407                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
2408                 /* avoid a loop in the outermost scope, because eat_statement doesn't
2409                  * eat '}' */
2410                 if(token.type == '}' && current_function == NULL) {
2411                         next_token();
2412                 } else {
2413                         eat_statement();
2414                 }
2415                 return NULL;
2416         }
2417
2418         construct_type_t *p = last;
2419
2420         while(true) {
2421                 construct_type_t *type;
2422                 switch(token.type) {
2423                 case '(':
2424                         type = parse_function_declarator(declaration);
2425                         break;
2426                 case '[':
2427                         type = parse_array_declarator();
2428                         break;
2429                 default:
2430                         goto declarator_finished;
2431                 }
2432
2433                 /* insert in the middle of the list (behind p) */
2434                 if(p != NULL) {
2435                         type->next = p->next;
2436                         p->next    = type;
2437                 } else {
2438                         type->next = first;
2439                         first      = type;
2440                 }
2441                 if(last == p) {
2442                         last = type;
2443                 }
2444         }
2445
2446 declarator_finished:
2447         parse_attributes();
2448
2449         /* append inner_types at the end of the list, we don't to set last anymore
2450          * as it's not needed anymore */
2451         if(last == NULL) {
2452                 assert(first == NULL);
2453                 first = inner_types;
2454         } else {
2455                 last->next = inner_types;
2456         }
2457
2458         return first;
2459 }
2460
2461 static type_t *construct_declarator_type(construct_type_t *construct_list,
2462                                          type_t *type)
2463 {
2464         construct_type_t *iter = construct_list;
2465         for( ; iter != NULL; iter = iter->next) {
2466                 switch(iter->kind) {
2467                 case CONSTRUCT_INVALID:
2468                         panic("invalid type construction found");
2469                 case CONSTRUCT_FUNCTION: {
2470                         construct_function_type_t *construct_function_type
2471                                 = (construct_function_type_t*) iter;
2472
2473                         type_t *function_type = construct_function_type->function_type;
2474
2475                         function_type->function.return_type = type;
2476
2477                         type_t *skipped_return_type = skip_typeref(type);
2478                         if (is_type_function(skipped_return_type)) {
2479                                 errorf(HERE, "function returning function is not allowed");
2480                                 type = type_error_type;
2481                         } else if (is_type_array(skipped_return_type)) {
2482                                 errorf(HERE, "function returning array is not allowed");
2483                                 type = type_error_type;
2484                         } else {
2485                                 type = function_type;
2486                         }
2487                         break;
2488                 }
2489
2490                 case CONSTRUCT_POINTER: {
2491                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
2492                         type_t           *pointer_type   = allocate_type_zero(TYPE_POINTER, (source_position_t){NULL, 0});
2493                         pointer_type->pointer.points_to  = type;
2494                         pointer_type->base.qualifiers    = parsed_pointer->type_qualifiers;
2495
2496                         type = pointer_type;
2497                         break;
2498                 }
2499
2500                 case CONSTRUCT_ARRAY: {
2501                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
2502                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY, (source_position_t){NULL, 0});
2503
2504                         expression_t *size_expression
2505                                 = create_implicit_cast(parsed_array->size, type_size_t);
2506
2507                         array_type->base.qualifiers       = parsed_array->type_qualifiers;
2508                         array_type->array.element_type    = type;
2509                         array_type->array.is_static       = parsed_array->is_static;
2510                         array_type->array.is_variable     = parsed_array->is_variable;
2511                         array_type->array.size_expression = size_expression;
2512
2513                         if(size_expression != NULL) {
2514                                 if(is_constant_expression(size_expression)) {
2515                                         array_type->array.size_constant = true;
2516                                         array_type->array.size
2517                                                 = fold_constant(size_expression);
2518                                 } else {
2519                                         array_type->array.is_vla = true;
2520                                 }
2521                         }
2522
2523                         type_t *skipped_type = skip_typeref(type);
2524                         if (is_type_atomic(skipped_type, ATOMIC_TYPE_VOID)) {
2525                                 errorf(HERE, "array of void is not allowed");
2526                                 type = type_error_type;
2527                         } else {
2528                                 type = array_type;
2529                         }
2530                         break;
2531                 }
2532                 }
2533
2534                 type_t *hashed_type = typehash_insert(type);
2535                 if(hashed_type != type) {
2536                         /* the function type was constructed earlier freeing it here will
2537                          * destroy other types... */
2538                         if(iter->kind != CONSTRUCT_FUNCTION) {
2539                                 free_type(type);
2540                         }
2541                         type = hashed_type;
2542                 }
2543         }
2544
2545         return type;
2546 }
2547
2548 static declaration_t *parse_declarator(
2549                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
2550 {
2551         declaration_t *const declaration    = allocate_declaration_zero();
2552         declaration->declared_storage_class = specifiers->declared_storage_class;
2553         declaration->modifiers              = specifiers->decl_modifiers;
2554         declaration->is_inline              = specifiers->is_inline;
2555
2556         declaration->storage_class          = specifiers->declared_storage_class;
2557         if(declaration->storage_class == STORAGE_CLASS_NONE
2558                         && scope != global_scope) {
2559                 declaration->storage_class = STORAGE_CLASS_AUTO;
2560         }
2561
2562         construct_type_t *construct_type
2563                 = parse_inner_declarator(declaration, may_be_abstract);
2564         type_t *const type = specifiers->type;
2565         declaration->type = construct_declarator_type(construct_type, type);
2566
2567         if(construct_type != NULL) {
2568                 obstack_free(&temp_obst, construct_type);
2569         }
2570
2571         return declaration;
2572 }
2573
2574 static type_t *parse_abstract_declarator(type_t *base_type)
2575 {
2576         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2577
2578         type_t *result = construct_declarator_type(construct_type, base_type);
2579         if(construct_type != NULL) {
2580                 obstack_free(&temp_obst, construct_type);
2581         }
2582
2583         return result;
2584 }
2585
2586 static declaration_t *append_declaration(declaration_t* const declaration)
2587 {
2588         if (last_declaration != NULL) {
2589                 last_declaration->next = declaration;
2590         } else {
2591                 scope->declarations = declaration;
2592         }
2593         last_declaration = declaration;
2594         return declaration;
2595 }
2596
2597 /**
2598  * Check if the declaration of main is suspicious.  main should be a
2599  * function with external linkage, returning int, taking either zero
2600  * arguments, two, or three arguments of appropriate types, ie.
2601  *
2602  * int main([ int argc, char **argv [, char **env ] ]).
2603  *
2604  * @param decl    the declaration to check
2605  * @param type    the function type of the declaration
2606  */
2607 static void check_type_of_main(const declaration_t *const decl, const function_type_t *const func_type)
2608 {
2609         if (decl->storage_class == STORAGE_CLASS_STATIC) {
2610                 warningf(decl->source_position, "'main' is normally a non-static function");
2611         }
2612         if (skip_typeref(func_type->return_type) != type_int) {
2613                 warningf(decl->source_position, "return type of 'main' should be 'int', but is '%T'", func_type->return_type);
2614         }
2615         const function_parameter_t *parm = func_type->parameters;
2616         if (parm != NULL) {
2617                 type_t *const first_type = parm->type;
2618                 if (!types_compatible(skip_typeref(first_type), type_int)) {
2619                         warningf(decl->source_position, "first argument of 'main' should be 'int', but is '%T'", first_type);
2620                 }
2621                 parm = parm->next;
2622                 if (parm != NULL) {
2623                         type_t *const second_type = parm->type;
2624                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
2625                                 warningf(decl->source_position, "second argument of 'main' should be 'char**', but is '%T'", second_type);
2626                         }
2627                         parm = parm->next;
2628                         if (parm != NULL) {
2629                                 type_t *const third_type = parm->type;
2630                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
2631                                         warningf(decl->source_position, "third argument of 'main' should be 'char**', but is '%T'", third_type);
2632                                 }
2633                                 parm = parm->next;
2634                                 if (parm != NULL) {
2635                                         warningf(decl->source_position, "'main' takes only zero, two or three arguments");
2636                                 }
2637                         }
2638                 } else {
2639                         warningf(decl->source_position, "'main' takes only zero, two or three arguments");
2640                 }
2641         }
2642 }
2643
2644 /**
2645  * Check if a symbol is the equal to "main".
2646  */
2647 static bool is_sym_main(const symbol_t *const sym)
2648 {
2649         return strcmp(sym->string, "main") == 0;
2650 }
2651
2652 static declaration_t *internal_record_declaration(
2653         declaration_t *const declaration,
2654         const bool is_function_definition)
2655 {
2656         const symbol_t *const symbol  = declaration->symbol;
2657         const namespace_t     namespc = (namespace_t)declaration->namespc;
2658
2659         type_t *const orig_type = declaration->type;
2660         type_t *const type      = skip_typeref(orig_type);
2661         if (is_type_function(type) &&
2662                         type->function.unspecified_parameters &&
2663                         warning.strict_prototypes) {
2664                 warningf(declaration->source_position,
2665                          "function declaration '%#T' is not a prototype",
2666                          orig_type, declaration->symbol);
2667         }
2668
2669         if (is_function_definition && warning.main && is_sym_main(symbol)) {
2670                 check_type_of_main(declaration, &type->function);
2671         }
2672
2673         assert(declaration->symbol != NULL);
2674         declaration_t *previous_declaration = get_declaration(symbol, namespc);
2675
2676         assert(declaration != previous_declaration);
2677         if (previous_declaration != NULL) {
2678                 if (previous_declaration->parent_scope == scope) {
2679                         /* can happen for K&R style declarations */
2680                         if(previous_declaration->type == NULL) {
2681                                 previous_declaration->type = declaration->type;
2682                         }
2683
2684                         const type_t *prev_type = skip_typeref(previous_declaration->type);
2685                         if (!types_compatible(type, prev_type)) {
2686                                 errorf(declaration->source_position,
2687                                        "declaration '%#T' is incompatible with "
2688                                        "previous declaration '%#T'",
2689                                        orig_type, symbol, previous_declaration->type, symbol);
2690                                 errorf(previous_declaration->source_position,
2691                                        "previous declaration of '%Y' was here", symbol);
2692                         } else {
2693                                 unsigned old_storage_class
2694                                         = previous_declaration->storage_class;
2695                                 unsigned new_storage_class = declaration->storage_class;
2696
2697                                 if(is_type_incomplete(prev_type)) {
2698                                         previous_declaration->type = type;
2699                                         prev_type                  = type;
2700                                 }
2701
2702                                 /* pretend no storage class means extern for function
2703                                  * declarations (except if the previous declaration is neither
2704                                  * none nor extern) */
2705                                 if (is_type_function(type)) {
2706                                         switch (old_storage_class) {
2707                                                 case STORAGE_CLASS_NONE:
2708                                                         old_storage_class = STORAGE_CLASS_EXTERN;
2709
2710                                                 case STORAGE_CLASS_EXTERN:
2711                                                         if (is_function_definition) {
2712                                                                 if (warning.missing_prototypes &&
2713                                                                     prev_type->function.unspecified_parameters &&
2714                                                                     !is_sym_main(symbol)) {
2715                                                                         warningf(declaration->source_position,
2716                                                                                  "no previous prototype for '%#T'",
2717                                                                                  orig_type, symbol);
2718                                                                 }
2719                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
2720                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
2721                                                         }
2722                                                         break;
2723
2724                                                 default: break;
2725                                         }
2726                                 }
2727
2728                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
2729                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
2730 warn_redundant_declaration:
2731                                         if (warning.redundant_decls) {
2732                                                 warningf(declaration->source_position,
2733                                                          "redundant declaration for '%Y'", symbol);
2734                                                 warningf(previous_declaration->source_position,
2735                                                          "previous declaration of '%Y' was here",
2736                                                          symbol);
2737                                         }
2738                                 } else if (current_function == NULL) {
2739                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
2740                                                         new_storage_class == STORAGE_CLASS_STATIC) {
2741                                                 errorf(declaration->source_position,
2742                                                        "static declaration of '%Y' follows non-static declaration",
2743                                                        symbol);
2744                                                 errorf(previous_declaration->source_position,
2745                                                        "previous declaration of '%Y' was here", symbol);
2746                                         } else {
2747                                                 if (old_storage_class != STORAGE_CLASS_EXTERN && !is_function_definition) {
2748                                                         goto warn_redundant_declaration;
2749                                                 }
2750                                                 if (new_storage_class == STORAGE_CLASS_NONE) {
2751                                                         previous_declaration->storage_class = STORAGE_CLASS_NONE;
2752                                                         previous_declaration->declared_storage_class = STORAGE_CLASS_NONE;
2753                                                 }
2754                                         }
2755                                 } else {
2756                                         if (old_storage_class == new_storage_class) {
2757                                                 errorf(declaration->source_position,
2758                                                        "redeclaration of '%Y'", symbol);
2759                                         } else {
2760                                                 errorf(declaration->source_position,
2761                                                        "redeclaration of '%Y' with different linkage",
2762                                                        symbol);
2763                                         }
2764                                         errorf(previous_declaration->source_position,
2765                                                "previous declaration of '%Y' was here", symbol);
2766                                 }
2767                         }
2768                         return previous_declaration;
2769                 }
2770         } else if (is_function_definition) {
2771                 if (declaration->storage_class != STORAGE_CLASS_STATIC) {
2772                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
2773                                 warningf(declaration->source_position,
2774                                          "no previous prototype for '%#T'", orig_type, symbol);
2775                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
2776                                 warningf(declaration->source_position,
2777                                          "no previous declaration for '%#T'", orig_type,
2778                                          symbol);
2779                         }
2780                 }
2781         } else if (warning.missing_declarations &&
2782             scope == global_scope &&
2783             !is_type_function(type) && (
2784               declaration->storage_class == STORAGE_CLASS_NONE ||
2785               declaration->storage_class == STORAGE_CLASS_THREAD
2786             )) {
2787                 warningf(declaration->source_position,
2788                          "no previous declaration for '%#T'", orig_type, symbol);
2789         }
2790
2791         assert(declaration->parent_scope == NULL);
2792         assert(scope != NULL);
2793
2794         declaration->parent_scope = scope;
2795
2796         environment_push(declaration);
2797         return append_declaration(declaration);
2798 }
2799
2800 static declaration_t *record_declaration(declaration_t *declaration)
2801 {
2802         return internal_record_declaration(declaration, false);
2803 }
2804
2805 static declaration_t *record_function_definition(declaration_t *declaration)
2806 {
2807         return internal_record_declaration(declaration, true);
2808 }
2809
2810 static void parser_error_multiple_definition(declaration_t *declaration,
2811                 const source_position_t source_position)
2812 {
2813         errorf(source_position, "multiple definition of symbol '%Y'",
2814                declaration->symbol);
2815         errorf(declaration->source_position,
2816                "this is the location of the previous definition.");
2817 }
2818
2819 static bool is_declaration_specifier(const token_t *token,
2820                                      bool only_type_specifiers)
2821 {
2822         switch(token->type) {
2823                 TYPE_SPECIFIERS
2824                         return true;
2825                 case T_IDENTIFIER:
2826                         return is_typedef_symbol(token->v.symbol);
2827
2828                 case T___extension__:
2829                 STORAGE_CLASSES
2830                 TYPE_QUALIFIERS
2831                         return !only_type_specifiers;
2832
2833                 default:
2834                         return false;
2835         }
2836 }
2837
2838 static void parse_init_declarator_rest(declaration_t *declaration)
2839 {
2840         eat('=');
2841
2842         type_t *orig_type = declaration->type;
2843         type_t *type      = skip_typeref(orig_type);
2844
2845         if(declaration->init.initializer != NULL) {
2846                 parser_error_multiple_definition(declaration, token.source_position);
2847         }
2848
2849         bool must_be_constant = false;
2850         if(declaration->storage_class == STORAGE_CLASS_STATIC
2851                         || declaration->storage_class == STORAGE_CLASS_THREAD_STATIC
2852                         || declaration->parent_scope == global_scope) {
2853                 must_be_constant = true;
2854         }
2855
2856         parse_initializer_env_t env;
2857         env.type             = orig_type;
2858         env.must_be_constant = must_be_constant;
2859         parse_initializer(&env);
2860
2861         if(env.type != orig_type) {
2862                 orig_type         = env.type;
2863                 type              = skip_typeref(orig_type);
2864                 declaration->type = env.type;
2865         }
2866
2867         if(is_type_function(type)) {
2868                 errorf(declaration->source_position,
2869                        "initializers not allowed for function types at declator '%Y' (type '%T')",
2870                        declaration->symbol, orig_type);
2871         } else {
2872                 declaration->init.initializer = env.initializer;
2873         }
2874 }
2875
2876 /* parse rest of a declaration without any declarator */
2877 static void parse_anonymous_declaration_rest(
2878                 const declaration_specifiers_t *specifiers,
2879                 parsed_declaration_func finished_declaration)
2880 {
2881         eat(';');
2882
2883         declaration_t *const declaration    = allocate_declaration_zero();
2884         declaration->type                   = specifiers->type;
2885         declaration->declared_storage_class = specifiers->declared_storage_class;
2886         declaration->source_position        = specifiers->source_position;
2887
2888         if (declaration->declared_storage_class != STORAGE_CLASS_NONE) {
2889                 warningf(declaration->source_position, "useless storage class in empty declaration");
2890         }
2891         declaration->storage_class = STORAGE_CLASS_NONE;
2892
2893         type_t *type = declaration->type;
2894         switch (type->kind) {
2895                 case TYPE_COMPOUND_STRUCT:
2896                 case TYPE_COMPOUND_UNION: {
2897                         if (type->compound.declaration->symbol == NULL) {
2898                                 warningf(declaration->source_position, "unnamed struct/union that defines no instances");
2899                         }
2900                         break;
2901                 }
2902
2903                 case TYPE_ENUM:
2904                         break;
2905
2906                 default:
2907                         warningf(declaration->source_position, "empty declaration");
2908                         break;
2909         }
2910
2911         finished_declaration(declaration);
2912 }
2913
2914 static void parse_declaration_rest(declaration_t *ndeclaration,
2915                 const declaration_specifiers_t *specifiers,
2916                 parsed_declaration_func finished_declaration)
2917 {
2918         while(true) {
2919                 declaration_t *declaration = finished_declaration(ndeclaration);
2920
2921                 type_t *orig_type = declaration->type;
2922                 type_t *type      = skip_typeref(orig_type);
2923
2924                 if (type->kind != TYPE_FUNCTION &&
2925                     declaration->is_inline &&
2926                     is_type_valid(type)) {
2927                         warningf(declaration->source_position,
2928                                  "variable '%Y' declared 'inline'\n", declaration->symbol);
2929                 }
2930
2931                 if(token.type == '=') {
2932                         parse_init_declarator_rest(declaration);
2933                 }
2934
2935                 if(token.type != ',')
2936                         break;
2937                 eat(',');
2938
2939                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
2940         }
2941         expect_void(';');
2942 }
2943
2944 static declaration_t *finished_kr_declaration(declaration_t *declaration)
2945 {
2946         symbol_t *symbol  = declaration->symbol;
2947         if(symbol == NULL) {
2948                 errorf(HERE, "anonymous declaration not valid as function parameter");
2949                 return declaration;
2950         }
2951         namespace_t namespc = (namespace_t) declaration->namespc;
2952         if(namespc != NAMESPACE_NORMAL) {
2953                 return record_declaration(declaration);
2954         }
2955
2956         declaration_t *previous_declaration = get_declaration(symbol, namespc);
2957         if(previous_declaration == NULL ||
2958                         previous_declaration->parent_scope != scope) {
2959                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
2960                        symbol);
2961                 return declaration;
2962         }
2963
2964         if(previous_declaration->type == NULL) {
2965                 previous_declaration->type          = declaration->type;
2966                 previous_declaration->declared_storage_class = declaration->declared_storage_class;
2967                 previous_declaration->storage_class = declaration->storage_class;
2968                 previous_declaration->parent_scope  = scope;
2969                 return previous_declaration;
2970         } else {
2971                 return record_declaration(declaration);
2972         }
2973 }
2974
2975 static void parse_declaration(parsed_declaration_func finished_declaration)
2976 {
2977         declaration_specifiers_t specifiers;
2978         memset(&specifiers, 0, sizeof(specifiers));
2979         parse_declaration_specifiers(&specifiers);
2980
2981         if(token.type == ';') {
2982                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
2983         } else {
2984                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2985                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
2986         }
2987 }
2988
2989 static void parse_kr_declaration_list(declaration_t *declaration)
2990 {
2991         type_t *type = skip_typeref(declaration->type);
2992         if(!is_type_function(type))
2993                 return;
2994
2995         if(!type->function.kr_style_parameters)
2996                 return;
2997
2998         /* push function parameters */
2999         int       top        = environment_top();
3000         scope_t  *last_scope = scope;
3001         set_scope(&declaration->scope);
3002
3003         declaration_t *parameter = declaration->scope.declarations;
3004         for( ; parameter != NULL; parameter = parameter->next) {
3005                 assert(parameter->parent_scope == NULL);
3006                 parameter->parent_scope = scope;
3007                 environment_push(parameter);
3008         }
3009
3010         /* parse declaration list */
3011         while(is_declaration_specifier(&token, false)) {
3012                 parse_declaration(finished_kr_declaration);
3013         }
3014
3015         /* pop function parameters */
3016         assert(scope == &declaration->scope);
3017         set_scope(last_scope);
3018         environment_pop_to(top);
3019
3020         /* update function type */
3021         type_t *new_type = duplicate_type(type);
3022         new_type->function.kr_style_parameters = false;
3023
3024         function_parameter_t *parameters     = NULL;
3025         function_parameter_t *last_parameter = NULL;
3026
3027         declaration_t *parameter_declaration = declaration->scope.declarations;
3028         for( ; parameter_declaration != NULL;
3029                         parameter_declaration = parameter_declaration->next) {
3030                 type_t *parameter_type = parameter_declaration->type;
3031                 if(parameter_type == NULL) {
3032                         if (strict_mode) {
3033                                 errorf(HERE, "no type specified for function parameter '%Y'",
3034                                        parameter_declaration->symbol);
3035                         } else {
3036                                 if (warning.implicit_int) {
3037                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
3038                                                 parameter_declaration->symbol);
3039                                 }
3040                                 parameter_type              = type_int;
3041                                 parameter_declaration->type = parameter_type;
3042                         }
3043                 }
3044
3045                 semantic_parameter(parameter_declaration);
3046                 parameter_type = parameter_declaration->type;
3047
3048                 function_parameter_t *function_parameter
3049                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
3050                 memset(function_parameter, 0, sizeof(function_parameter[0]));
3051
3052                 function_parameter->type = parameter_type;
3053                 if(last_parameter != NULL) {
3054                         last_parameter->next = function_parameter;
3055                 } else {
3056                         parameters = function_parameter;
3057                 }
3058                 last_parameter = function_parameter;
3059         }
3060         new_type->function.parameters = parameters;
3061
3062         type = typehash_insert(new_type);
3063         if(type != new_type) {
3064                 obstack_free(type_obst, new_type);
3065         }
3066
3067         declaration->type = type;
3068 }
3069
3070 static bool first_err = true;
3071
3072 /**
3073  * When called with first_err set, prints the name of the current function,
3074  * else does noting.
3075  */
3076 static void print_in_function(void) {
3077         if (first_err) {
3078                 first_err = false;
3079                 diagnosticf("%s: In function '%Y':\n",
3080                         current_function->source_position.input_name,
3081                         current_function->symbol);
3082         }
3083 }
3084
3085 /**
3086  * Check if all labels are defined in the current function.
3087  * Check if all labels are used in the current function.
3088  */
3089 static void check_labels(void)
3090 {
3091         for (const goto_statement_t *goto_statement = goto_first;
3092             goto_statement != NULL;
3093             goto_statement = goto_statement->next) {
3094                 declaration_t *label = goto_statement->label;
3095
3096                 label->used = true;
3097                 if (label->source_position.input_name == NULL) {
3098                         print_in_function();
3099                         errorf(goto_statement->base.source_position,
3100                                "label '%Y' used but not defined", label->symbol);
3101                  }
3102         }
3103         goto_first = goto_last = NULL;
3104
3105         if (warning.unused_label) {
3106                 for (const label_statement_t *label_statement = label_first;
3107                          label_statement != NULL;
3108                          label_statement = label_statement->next) {
3109                         const declaration_t *label = label_statement->label;
3110
3111                         if (! label->used) {
3112                                 print_in_function();
3113                                 warningf(label_statement->base.source_position,
3114                                         "label '%Y' defined but not used", label->symbol);
3115                         }
3116                 }
3117         }
3118         label_first = label_last = NULL;
3119 }
3120
3121 /**
3122  * Check declarations of current_function for unused entities.
3123  */
3124 static void check_declarations(void)
3125 {
3126         if (warning.unused_parameter) {
3127                 const scope_t *scope = &current_function->scope;
3128
3129                 const declaration_t *parameter = scope->declarations;
3130                 for (; parameter != NULL; parameter = parameter->next) {
3131                         if (! parameter->used) {
3132                                 print_in_function();
3133                                 warningf(parameter->source_position,
3134                                         "unused parameter '%Y'", parameter->symbol);
3135                         }
3136                 }
3137         }
3138         if (warning.unused_variable) {
3139         }
3140 }
3141
3142 static void parse_external_declaration(void)
3143 {
3144         /* function-definitions and declarations both start with declaration
3145          * specifiers */
3146         declaration_specifiers_t specifiers;
3147         memset(&specifiers, 0, sizeof(specifiers));
3148         parse_declaration_specifiers(&specifiers);
3149
3150         /* must be a declaration */
3151         if(token.type == ';') {
3152                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
3153                 return;
3154         }
3155
3156         /* declarator is common to both function-definitions and declarations */
3157         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
3158
3159         /* must be a declaration */
3160         if(token.type == ',' || token.type == '=' || token.type == ';') {
3161                 parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
3162                 return;
3163         }
3164
3165         /* must be a function definition */
3166         parse_kr_declaration_list(ndeclaration);
3167
3168         if(token.type != '{') {
3169                 parse_error_expected("while parsing function definition", '{', 0);
3170                 eat_statement();
3171                 return;
3172         }
3173
3174         type_t *type = ndeclaration->type;
3175
3176         /* note that we don't skip typerefs: the standard doesn't allow them here
3177          * (so we can't use is_type_function here) */
3178         if(type->kind != TYPE_FUNCTION) {
3179                 if (is_type_valid(type)) {
3180                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
3181                                type, ndeclaration->symbol);
3182                 }
3183                 eat_block();
3184                 return;
3185         }
3186
3187         /* § 6.7.5.3 (14) a function definition with () means no
3188          * parameters (and not unspecified parameters) */
3189         if(type->function.unspecified_parameters) {
3190                 type_t *duplicate = duplicate_type(type);
3191                 duplicate->function.unspecified_parameters = false;
3192
3193                 type = typehash_insert(duplicate);
3194                 if(type != duplicate) {
3195                         obstack_free(type_obst, duplicate);
3196                 }
3197                 ndeclaration->type = type;
3198         }
3199
3200         declaration_t *const declaration = record_function_definition(ndeclaration);
3201         if(ndeclaration != declaration) {
3202                 declaration->scope = ndeclaration->scope;
3203         }
3204         type = skip_typeref(declaration->type);
3205
3206         /* push function parameters and switch scope */
3207         int       top        = environment_top();
3208         scope_t  *last_scope = scope;
3209         set_scope(&declaration->scope);
3210
3211         declaration_t *parameter = declaration->scope.declarations;
3212         for( ; parameter != NULL; parameter = parameter->next) {
3213                 if(parameter->parent_scope == &ndeclaration->scope) {
3214                         parameter->parent_scope = scope;
3215                 }
3216                 assert(parameter->parent_scope == NULL
3217                                 || parameter->parent_scope == scope);
3218                 parameter->parent_scope = scope;
3219                 environment_push(parameter);
3220         }
3221
3222         if(declaration->init.statement != NULL) {
3223                 parser_error_multiple_definition(declaration, token.source_position);
3224                 eat_block();
3225                 goto end_of_parse_external_declaration;
3226         } else {
3227                 /* parse function body */
3228                 int            label_stack_top      = label_top();
3229                 declaration_t *old_current_function = current_function;
3230                 current_function                    = declaration;
3231
3232                 declaration->init.statement = parse_compound_statement();
3233                 first_err = true;
3234                 check_labels();
3235                 check_declarations();
3236
3237                 assert(current_function == declaration);
3238                 current_function = old_current_function;
3239                 label_pop_to(label_stack_top);
3240         }
3241
3242 end_of_parse_external_declaration:
3243         assert(scope == &declaration->scope);
3244         set_scope(last_scope);
3245         environment_pop_to(top);
3246 }
3247
3248 static type_t *make_bitfield_type(type_t *base, expression_t *size,
3249                                   source_position_t source_position)
3250 {
3251         type_t *type        = allocate_type_zero(TYPE_BITFIELD, source_position);
3252         type->bitfield.base = base;
3253         type->bitfield.size = size;
3254
3255         return type;
3256 }
3257
3258 static declaration_t *find_compound_entry(declaration_t *compound_declaration,
3259                                           symbol_t *symbol)
3260 {
3261         declaration_t *iter = compound_declaration->scope.declarations;
3262         for( ; iter != NULL; iter = iter->next) {
3263                 if(iter->namespc != NAMESPACE_NORMAL)
3264                         continue;
3265
3266                 if(iter->symbol == NULL) {
3267                         type_t *type = skip_typeref(iter->type);
3268                         if(is_type_compound(type)) {
3269                                 declaration_t *result
3270                                         = find_compound_entry(type->compound.declaration, symbol);
3271                                 if(result != NULL)
3272                                         return result;
3273                         }
3274                         continue;
3275                 }
3276
3277                 if(iter->symbol == symbol) {
3278                         return iter;
3279                 }
3280         }
3281
3282         return NULL;
3283 }
3284
3285 static void parse_compound_declarators(declaration_t *struct_declaration,
3286                 const declaration_specifiers_t *specifiers)
3287 {
3288         declaration_t *last_declaration = struct_declaration->scope.declarations;
3289         if(last_declaration != NULL) {
3290                 while(last_declaration->next != NULL) {
3291                         last_declaration = last_declaration->next;
3292                 }
3293         }
3294
3295         while(1) {
3296                 declaration_t *declaration;
3297
3298                 if(token.type == ':') {
3299                         source_position_t source_position = HERE;
3300                         next_token();
3301
3302                         type_t *base_type = specifiers->type;
3303                         expression_t *size = parse_constant_expression();
3304
3305                         if(!is_type_integer(skip_typeref(base_type))) {
3306                                 errorf(HERE, "bitfield base type '%T' is not an integer type",
3307                                        base_type);
3308                         }
3309
3310                         type_t *type = make_bitfield_type(base_type, size, source_position);
3311
3312                         declaration                         = allocate_declaration_zero();
3313                         declaration->namespc                = NAMESPACE_NORMAL;
3314                         declaration->declared_storage_class = STORAGE_CLASS_NONE;
3315                         declaration->storage_class          = STORAGE_CLASS_NONE;
3316                         declaration->source_position        = source_position;
3317                         declaration->modifiers              = specifiers->decl_modifiers;
3318                         declaration->type                   = type;
3319                 } else {
3320                         declaration = parse_declarator(specifiers,/*may_be_abstract=*/true);
3321
3322                         type_t *orig_type = declaration->type;
3323                         type_t *type      = skip_typeref(orig_type);
3324
3325                         if(token.type == ':') {
3326                                 source_position_t source_position = HERE;
3327                                 next_token();
3328                                 expression_t *size = parse_constant_expression();
3329
3330                                 if(!is_type_integer(type)) {
3331                                         errorf(HERE, "bitfield base type '%T' is not an "
3332                                                "integer type", orig_type);
3333                                 }
3334
3335                                 type_t *bitfield_type = make_bitfield_type(orig_type, size, source_position);
3336                                 declaration->type = bitfield_type;
3337                         } else {
3338                                 /* TODO we ignore arrays for now... what is missing is a check
3339                                  * that they're at the end of the struct */
3340                                 if(is_type_incomplete(type) && !is_type_array(type)) {
3341                                         errorf(HERE,
3342                                                "compound member '%Y' has incomplete type '%T'",
3343                                                declaration->symbol, orig_type);
3344                                 } else if(is_type_function(type)) {
3345                                         errorf(HERE, "compound member '%Y' must not have function "
3346                                                "type '%T'", declaration->symbol, orig_type);
3347                                 }
3348                         }
3349                 }
3350
3351                 /* make sure we don't define a symbol multiple times */
3352                 symbol_t *symbol = declaration->symbol;
3353                 if(symbol != NULL) {
3354                         declaration_t *prev_decl
3355                                 = find_compound_entry(struct_declaration, symbol);
3356
3357                         if(prev_decl != NULL) {
3358                                 assert(prev_decl->symbol == symbol);
3359                                 errorf(declaration->source_position,
3360                                        "multiple declarations of symbol '%Y'", symbol);
3361                                 errorf(prev_decl->source_position,
3362                                        "previous declaration of '%Y' was here", symbol);
3363                         }
3364                 }
3365
3366                 /* append declaration */
3367                 if(last_declaration != NULL) {
3368                         last_declaration->next = declaration;
3369                 } else {
3370                         struct_declaration->scope.declarations = declaration;
3371                 }
3372                 last_declaration = declaration;
3373
3374                 if(token.type != ',')
3375                         break;
3376                 next_token();
3377         }
3378         expect_void(';');
3379 }
3380
3381 static void parse_compound_type_entries(declaration_t *compound_declaration)
3382 {
3383         eat('{');
3384
3385         while(token.type != '}' && token.type != T_EOF) {
3386                 declaration_specifiers_t specifiers;
3387                 memset(&specifiers, 0, sizeof(specifiers));
3388                 parse_declaration_specifiers(&specifiers);
3389
3390                 parse_compound_declarators(compound_declaration, &specifiers);
3391         }
3392         if(token.type == T_EOF) {
3393                 errorf(HERE, "EOF while parsing struct");
3394         }
3395         next_token();
3396 }
3397
3398 static type_t *parse_typename(void)
3399 {
3400         declaration_specifiers_t specifiers;
3401         memset(&specifiers, 0, sizeof(specifiers));
3402         parse_declaration_specifiers(&specifiers);
3403         if(specifiers.declared_storage_class != STORAGE_CLASS_NONE) {
3404                 /* TODO: improve error message, user does probably not know what a
3405                  * storage class is...
3406                  */
3407                 errorf(HERE, "typename may not have a storage class");
3408         }
3409
3410         type_t *result = parse_abstract_declarator(specifiers.type);
3411
3412         return result;
3413 }
3414
3415
3416
3417
3418 typedef expression_t* (*parse_expression_function) (unsigned precedence);
3419 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
3420                                                           expression_t *left);
3421
3422 typedef struct expression_parser_function_t expression_parser_function_t;
3423 struct expression_parser_function_t {
3424         unsigned                         precedence;
3425         parse_expression_function        parser;
3426         unsigned                         infix_precedence;
3427         parse_expression_infix_function  infix_parser;
3428 };
3429
3430 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
3431
3432 /**
3433  * Creates a new invalid expression.
3434  */
3435 static expression_t *create_invalid_expression(void)
3436 {
3437         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
3438         expression->base.source_position = token.source_position;
3439         return expression;
3440 }
3441
3442 /**
3443  * Prints an error message if an expression was expected but not read
3444  */
3445 static expression_t *expected_expression_error(void)
3446 {
3447         /* skip the error message if the error token was read */
3448         if (token.type != T_ERROR) {
3449                 errorf(HERE, "expected expression, got token '%K'", &token);
3450         }
3451         next_token();
3452
3453         return create_invalid_expression();
3454 }
3455
3456 /**
3457  * Parse a string constant.
3458  */
3459 static expression_t *parse_string_const(void)
3460 {
3461         wide_string_t wres;
3462         if (token.type == T_STRING_LITERAL) {
3463                 string_t res = token.v.string;
3464                 next_token();
3465                 while (token.type == T_STRING_LITERAL) {
3466                         res = concat_strings(&res, &token.v.string);
3467                         next_token();
3468                 }
3469                 if (token.type != T_WIDE_STRING_LITERAL) {
3470                         expression_t *const cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
3471                         /* note: that we use type_char_ptr here, which is already the
3472                          * automatic converted type. revert_automatic_type_conversion
3473                          * will construct the array type */
3474                         cnst->base.type    = type_char_ptr;
3475                         cnst->string.value = res;
3476                         return cnst;
3477                 }
3478
3479                 wres = concat_string_wide_string(&res, &token.v.wide_string);
3480         } else {
3481                 wres = token.v.wide_string;
3482         }
3483         next_token();
3484
3485         for (;;) {
3486                 switch (token.type) {
3487                         case T_WIDE_STRING_LITERAL:
3488                                 wres = concat_wide_strings(&wres, &token.v.wide_string);
3489                                 break;
3490
3491                         case T_STRING_LITERAL:
3492                                 wres = concat_wide_string_string(&wres, &token.v.string);
3493                                 break;
3494
3495                         default: {
3496                                 expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
3497                                 cnst->base.type         = type_wchar_t_ptr;
3498                                 cnst->wide_string.value = wres;
3499                                 return cnst;
3500                         }
3501                 }
3502                 next_token();
3503         }
3504 }
3505
3506 /**
3507  * Parse an integer constant.
3508  */
3509 static expression_t *parse_int_const(void)
3510 {
3511         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
3512         cnst->base.source_position = HERE;
3513         cnst->base.type            = token.datatype;
3514         cnst->conste.v.int_value   = token.v.intvalue;
3515
3516         next_token();
3517
3518         return cnst;
3519 }
3520
3521 /**
3522  * Parse a character constant.
3523  */
3524 static expression_t *parse_char_const(void)
3525 {
3526         expression_t *cnst         = allocate_expression_zero(EXPR_CHAR_CONST);
3527         cnst->base.source_position = HERE;
3528         cnst->base.type            = token.datatype;
3529         cnst->conste.v.chars.begin = token.v.string.begin;
3530         cnst->conste.v.chars.size  = token.v.string.size;
3531
3532         if (cnst->conste.v.chars.size != 1) {
3533                 if (warning.multichar && (c_mode & _GNUC)) {
3534                         /* TODO */
3535                         warningf(HERE, "multi-character character constant");
3536                 } else {
3537                         errorf(HERE, "more than 1 characters in character constant");
3538                 }
3539         }
3540         next_token();
3541
3542         return cnst;
3543 }
3544
3545 /**
3546  * Parse a float constant.
3547  */
3548 static expression_t *parse_float_const(void)
3549 {
3550         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
3551         cnst->base.type            = token.datatype;
3552         cnst->conste.v.float_value = token.v.floatvalue;
3553
3554         next_token();
3555
3556         return cnst;
3557 }
3558
3559 static declaration_t *create_implicit_function(symbol_t *symbol,
3560                 const source_position_t source_position)
3561 {
3562         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION, source_position);
3563         ntype->function.return_type            = type_int;
3564         ntype->function.unspecified_parameters = true;
3565
3566         type_t *type = typehash_insert(ntype);
3567         if(type != ntype) {
3568                 free_type(ntype);
3569         }
3570
3571         declaration_t *const declaration    = allocate_declaration_zero();
3572         declaration->storage_class          = STORAGE_CLASS_EXTERN;
3573         declaration->declared_storage_class = STORAGE_CLASS_EXTERN;
3574         declaration->type                   = type;
3575         declaration->symbol                 = symbol;
3576         declaration->source_position        = source_position;
3577         declaration->parent_scope           = global_scope;
3578
3579         scope_t *old_scope = scope;
3580         set_scope(global_scope);
3581
3582         environment_push(declaration);
3583         /* prepends the declaration to the global declarations list */
3584         declaration->next   = scope->declarations;
3585         scope->declarations = declaration;
3586
3587         assert(scope == global_scope);
3588         set_scope(old_scope);
3589
3590         return declaration;
3591 }
3592
3593 /**
3594  * Creates a return_type (func)(argument_type) function type if not
3595  * already exists.
3596  *
3597  * @param return_type    the return type
3598  * @param argument_type  the argument type
3599  */
3600 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
3601 {
3602         function_parameter_t *parameter
3603                 = obstack_alloc(type_obst, sizeof(parameter[0]));
3604         memset(parameter, 0, sizeof(parameter[0]));
3605         parameter->type = argument_type;
3606
3607         type_t *type               = allocate_type_zero(TYPE_FUNCTION, builtin_source_position);
3608         type->function.return_type = return_type;
3609         type->function.parameters  = parameter;
3610
3611         type_t *result = typehash_insert(type);
3612         if(result != type) {
3613                 free_type(type);
3614         }
3615
3616         return result;
3617 }
3618
3619 /**
3620  * Creates a function type for some function like builtins.
3621  *
3622  * @param symbol   the symbol describing the builtin
3623  */
3624 static type_t *get_builtin_symbol_type(symbol_t *symbol)
3625 {
3626         switch(symbol->ID) {
3627         case T___builtin_alloca:
3628                 return make_function_1_type(type_void_ptr, type_size_t);
3629         case T___builtin_nan:
3630                 return make_function_1_type(type_double, type_char_ptr);
3631         case T___builtin_nanf:
3632                 return make_function_1_type(type_float, type_char_ptr);
3633         case T___builtin_nand:
3634                 return make_function_1_type(type_long_double, type_char_ptr);
3635         case T___builtin_va_end:
3636                 return make_function_1_type(type_void, type_valist);
3637         default:
3638                 panic("not implemented builtin symbol found");
3639         }
3640 }
3641
3642 /**
3643  * Performs automatic type cast as described in § 6.3.2.1.
3644  *
3645  * @param orig_type  the original type
3646  */
3647 static type_t *automatic_type_conversion(type_t *orig_type)
3648 {
3649         type_t *type = skip_typeref(orig_type);
3650         if(is_type_array(type)) {
3651                 array_type_t *array_type   = &type->array;
3652                 type_t       *element_type = array_type->element_type;
3653                 unsigned      qualifiers   = array_type->type.qualifiers;
3654
3655                 return make_pointer_type(element_type, qualifiers);
3656         }
3657
3658         if(is_type_function(type)) {
3659                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3660         }
3661
3662         return orig_type;
3663 }
3664
3665 /**
3666  * reverts the automatic casts of array to pointer types and function
3667  * to function-pointer types as defined § 6.3.2.1
3668  */
3669 type_t *revert_automatic_type_conversion(const expression_t *expression)
3670 {
3671         switch (expression->kind) {
3672                 case EXPR_REFERENCE: return expression->reference.declaration->type;
3673                 case EXPR_SELECT:    return expression->select.compound_entry->type;
3674
3675                 case EXPR_UNARY_DEREFERENCE: {
3676                         const expression_t *const value = expression->unary.value;
3677                         type_t             *const type  = skip_typeref(value->base.type);
3678                         assert(is_type_pointer(type));
3679                         return type->pointer.points_to;
3680                 }
3681
3682                 case EXPR_BUILTIN_SYMBOL:
3683                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
3684
3685                 case EXPR_ARRAY_ACCESS: {
3686                         const expression_t *array_ref = expression->array_access.array_ref;
3687                         type_t             *type_left = skip_typeref(array_ref->base.type);
3688                         if (!is_type_valid(type_left))
3689                                 return type_left;
3690                         assert(is_type_pointer(type_left));
3691                         return type_left->pointer.points_to;
3692                 }
3693
3694                 case EXPR_STRING_LITERAL: {
3695                         size_t size = expression->string.value.size;
3696                         return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
3697                 }
3698
3699                 case EXPR_WIDE_STRING_LITERAL: {
3700                         size_t size = expression->wide_string.value.size;
3701                         return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
3702                 }
3703
3704                 case EXPR_COMPOUND_LITERAL:
3705                         return expression->compound_literal.type;
3706
3707                 default: break;
3708         }
3709
3710         return expression->base.type;
3711 }
3712
3713 static expression_t *parse_reference(void)
3714 {
3715         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
3716
3717         reference_expression_t *ref = &expression->reference;
3718         ref->symbol = token.v.symbol;
3719
3720         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
3721
3722         source_position_t source_position = token.source_position;
3723         next_token();
3724
3725         if(declaration == NULL) {
3726                 if (! strict_mode && token.type == '(') {
3727                         /* an implicitly defined function */
3728                         if (warning.implicit_function_declaration) {
3729                                 warningf(HERE, "implicit declaration of function '%Y'",
3730                                         ref->symbol);
3731                         }
3732
3733                         declaration = create_implicit_function(ref->symbol,
3734                                                                source_position);
3735                 } else {
3736                         errorf(HERE, "unknown symbol '%Y' found.", ref->symbol);
3737                         return create_invalid_expression();
3738                 }
3739         }
3740
3741         type_t *type         = declaration->type;
3742
3743         /* we always do the auto-type conversions; the & and sizeof parser contains
3744          * code to revert this! */
3745         type = automatic_type_conversion(type);
3746
3747         ref->declaration = declaration;
3748         ref->base.type   = type;
3749
3750         /* this declaration is used */
3751         declaration->used = true;
3752
3753         return expression;
3754 }
3755
3756 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
3757 {
3758         (void) expression;
3759         (void) dest_type;
3760         /* TODO check if explicit cast is allowed and issue warnings/errors */
3761 }
3762
3763 static expression_t *parse_compound_literal(type_t *type)
3764 {
3765         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
3766
3767         parse_initializer_env_t env;
3768         env.type             = type;
3769         env.must_be_constant = false;
3770         parse_initializer(&env);
3771         type = env.type;
3772
3773         expression->compound_literal.type        = type;
3774         expression->compound_literal.initializer = env.initializer;
3775         expression->base.type                    = automatic_type_conversion(type);
3776
3777         return expression;
3778 }
3779
3780 static expression_t *parse_cast(void)
3781 {
3782         source_position_t source_position = token.source_position;
3783
3784         type_t *type  = parse_typename();
3785
3786         expect(')');
3787
3788         if(token.type == '{') {
3789                 return parse_compound_literal(type);
3790         }
3791
3792         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
3793         cast->base.source_position = source_position;
3794
3795         expression_t *value = parse_sub_expression(20);
3796
3797         check_cast_allowed(value, type);
3798
3799         cast->base.type   = type;
3800         cast->unary.value = value;
3801
3802         return cast;
3803 }
3804
3805 static expression_t *parse_statement_expression(void)
3806 {
3807         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
3808
3809         statement_t *statement           = parse_compound_statement();
3810         expression->statement.statement  = statement;
3811         expression->base.source_position = statement->base.source_position;
3812
3813         /* find last statement and use its type */
3814         type_t *type = type_void;
3815         const statement_t *stmt = statement->compound.statements;
3816         if (stmt != NULL) {
3817                 while (stmt->base.next != NULL)
3818                         stmt = stmt->base.next;
3819
3820                 if (stmt->kind == STATEMENT_EXPRESSION) {
3821                         type = stmt->expression.expression->base.type;
3822                 }
3823         } else {
3824                 warningf(expression->base.source_position, "empty statement expression ({})");
3825         }
3826         expression->base.type = type;
3827
3828         expect(')');
3829
3830         return expression;
3831 }
3832
3833 static expression_t *parse_brace_expression(void)
3834 {
3835         eat('(');
3836
3837         switch(token.type) {
3838         case '{':
3839                 /* gcc extension: a statement expression */
3840                 return parse_statement_expression();
3841
3842         TYPE_QUALIFIERS
3843         TYPE_SPECIFIERS
3844                 return parse_cast();
3845         case T_IDENTIFIER:
3846                 if(is_typedef_symbol(token.v.symbol)) {
3847                         return parse_cast();
3848                 }
3849         }
3850
3851         expression_t *result = parse_expression();
3852         expect(')');
3853
3854         return result;
3855 }
3856
3857 static expression_t *parse_function_keyword(void)
3858 {
3859         next_token();
3860         /* TODO */
3861
3862         if (current_function == NULL) {
3863                 errorf(HERE, "'__func__' used outside of a function");
3864         }
3865
3866         expression_t *expression = allocate_expression_zero(EXPR_FUNCTION);
3867         expression->base.type    = type_char_ptr;
3868
3869         return expression;
3870 }
3871
3872 static expression_t *parse_pretty_function_keyword(void)
3873 {
3874         eat(T___PRETTY_FUNCTION__);
3875         /* TODO */
3876
3877         if (current_function == NULL) {
3878                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
3879         }
3880
3881         expression_t *expression = allocate_expression_zero(EXPR_PRETTY_FUNCTION);
3882         expression->base.type    = type_char_ptr;
3883
3884         return expression;
3885 }
3886
3887 static designator_t *parse_designator(void)
3888 {
3889         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
3890         result->source_position = HERE;
3891
3892         if(token.type != T_IDENTIFIER) {
3893                 parse_error_expected("while parsing member designator",
3894                                      T_IDENTIFIER, 0);
3895                 eat_paren();
3896                 return NULL;
3897         }
3898         result->symbol = token.v.symbol;
3899         next_token();
3900
3901         designator_t *last_designator = result;
3902         while(true) {
3903                 if(token.type == '.') {
3904                         next_token();
3905                         if(token.type != T_IDENTIFIER) {
3906                                 parse_error_expected("while parsing member designator",
3907                                                      T_IDENTIFIER, 0);
3908                                 eat_paren();
3909                                 return NULL;
3910                         }
3911                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
3912                         designator->source_position = HERE;
3913                         designator->symbol          = token.v.symbol;
3914                         next_token();
3915
3916                         last_designator->next = designator;
3917                         last_designator       = designator;
3918                         continue;
3919                 }
3920                 if(token.type == '[') {
3921                         next_token();
3922                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
3923                         designator->source_position = HERE;
3924                         designator->array_index     = parse_expression();
3925                         if(designator->array_index == NULL) {
3926                                 eat_paren();
3927                                 return NULL;
3928                         }
3929                         expect(']');
3930
3931                         last_designator->next = designator;
3932                         last_designator       = designator;
3933                         continue;
3934                 }
3935                 break;
3936         }
3937
3938         return result;
3939 }
3940
3941 static expression_t *parse_offsetof(void)
3942 {
3943         eat(T___builtin_offsetof);
3944
3945         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
3946         expression->base.type    = type_size_t;
3947
3948         expect('(');
3949         type_t *type = parse_typename();
3950         expect(',');
3951         designator_t *designator = parse_designator();
3952         expect(')');
3953
3954         expression->offsetofe.type       = type;
3955         expression->offsetofe.designator = designator;
3956
3957         type_path_t path;
3958         memset(&path, 0, sizeof(path));
3959         path.top_type = type;
3960         path.path     = NEW_ARR_F(type_path_entry_t, 0);
3961
3962         descend_into_subtype(&path);
3963
3964         if(!walk_designator(&path, designator, true)) {
3965                 return create_invalid_expression();
3966         }
3967
3968         DEL_ARR_F(path.path);
3969
3970         return expression;
3971 }
3972
3973 static expression_t *parse_va_start(void)
3974 {
3975         eat(T___builtin_va_start);
3976
3977         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
3978
3979         expect('(');
3980         expression->va_starte.ap = parse_assignment_expression();
3981         expect(',');
3982         expression_t *const expr = parse_assignment_expression();
3983         if (expr->kind == EXPR_REFERENCE) {
3984                 declaration_t *const decl = expr->reference.declaration;
3985                 if (decl == NULL)
3986                         return create_invalid_expression();
3987                 if (decl->parent_scope == &current_function->scope &&
3988                     decl->next == NULL) {
3989                         expression->va_starte.parameter = decl;
3990                         expect(')');
3991                         return expression;
3992                 }
3993         }
3994         errorf(expr->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
3995
3996         return create_invalid_expression();
3997 }
3998
3999 static expression_t *parse_va_arg(void)
4000 {
4001         eat(T___builtin_va_arg);
4002
4003         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
4004
4005         expect('(');
4006         expression->va_arge.ap = parse_assignment_expression();
4007         expect(',');
4008         expression->base.type = parse_typename();
4009         expect(')');
4010
4011         return expression;
4012 }
4013
4014 static expression_t *parse_builtin_symbol(void)
4015 {
4016         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
4017
4018         symbol_t *symbol = token.v.symbol;
4019
4020         expression->builtin_symbol.symbol = symbol;
4021         next_token();
4022
4023         type_t *type = get_builtin_symbol_type(symbol);
4024         type = automatic_type_conversion(type);
4025
4026         expression->base.type = type;
4027         return expression;
4028 }
4029
4030 static expression_t *parse_builtin_constant(void)
4031 {
4032         eat(T___builtin_constant_p);
4033
4034         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
4035
4036         expect('(');
4037         expression->builtin_constant.value = parse_assignment_expression();
4038         expect(')');
4039         expression->base.type = type_int;
4040
4041         return expression;
4042 }
4043
4044 static expression_t *parse_builtin_prefetch(void)
4045 {
4046         eat(T___builtin_prefetch);
4047
4048         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
4049
4050         expect('(');
4051         expression->builtin_prefetch.adr = parse_assignment_expression();
4052         if (token.type == ',') {
4053                 next_token();
4054                 expression->builtin_prefetch.rw = parse_assignment_expression();
4055         }
4056         if (token.type == ',') {
4057                 next_token();
4058                 expression->builtin_prefetch.locality = parse_assignment_expression();
4059         }
4060         expect(')');
4061         expression->base.type = type_void;
4062
4063         return expression;
4064 }
4065
4066 static expression_t *parse_compare_builtin(void)
4067 {
4068         expression_t *expression;
4069
4070         switch(token.type) {
4071         case T___builtin_isgreater:
4072                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
4073                 break;
4074         case T___builtin_isgreaterequal:
4075                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
4076                 break;
4077         case T___builtin_isless:
4078                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
4079                 break;
4080         case T___builtin_islessequal:
4081                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
4082                 break;
4083         case T___builtin_islessgreater:
4084                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
4085                 break;
4086         case T___builtin_isunordered:
4087                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
4088                 break;
4089         default:
4090                 panic("invalid compare builtin found");
4091                 break;
4092         }
4093         expression->base.source_position = HERE;
4094         next_token();
4095
4096         expect('(');
4097         expression->binary.left = parse_assignment_expression();
4098         expect(',');
4099         expression->binary.right = parse_assignment_expression();
4100         expect(')');
4101
4102         type_t *const orig_type_left  = expression->binary.left->base.type;
4103         type_t *const orig_type_right = expression->binary.right->base.type;
4104
4105         type_t *const type_left  = skip_typeref(orig_type_left);
4106         type_t *const type_right = skip_typeref(orig_type_right);
4107         if(!is_type_float(type_left) && !is_type_float(type_right)) {
4108                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4109                         type_error_incompatible("invalid operands in comparison",
4110                                 expression->base.source_position, orig_type_left, orig_type_right);
4111                 }
4112         } else {
4113                 semantic_comparison(&expression->binary);
4114         }
4115
4116         return expression;
4117 }
4118
4119 static expression_t *parse_builtin_expect(void)
4120 {
4121         eat(T___builtin_expect);
4122
4123         expression_t *expression
4124                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
4125
4126         expect('(');
4127         expression->binary.left = parse_assignment_expression();
4128         expect(',');
4129         expression->binary.right = parse_constant_expression();
4130         expect(')');
4131
4132         expression->base.type = expression->binary.left->base.type;
4133
4134         return expression;
4135 }
4136
4137 static expression_t *parse_assume(void) {
4138         eat(T_assume);
4139
4140         expression_t *expression
4141                 = allocate_expression_zero(EXPR_UNARY_ASSUME);
4142
4143         expect('(');
4144         expression->unary.value = parse_assignment_expression();
4145         expect(')');
4146
4147         expression->base.type = type_void;
4148         return expression;
4149 }
4150
4151 static expression_t *parse_primary_expression(void)
4152 {
4153         switch (token.type) {
4154                 case T_INTEGER:                  return parse_int_const();
4155                 case T_CHARS:                    return parse_char_const();
4156                 case T_FLOATINGPOINT:            return parse_float_const();
4157                 case T_STRING_LITERAL:
4158                 case T_WIDE_STRING_LITERAL:      return parse_string_const();
4159                 case T_IDENTIFIER:               return parse_reference();
4160                 case T___FUNCTION__:
4161                 case T___func__:                 return parse_function_keyword();
4162                 case T___PRETTY_FUNCTION__:      return parse_pretty_function_keyword();
4163                 case T___builtin_offsetof:       return parse_offsetof();
4164                 case T___builtin_va_start:       return parse_va_start();
4165                 case T___builtin_va_arg:         return parse_va_arg();
4166                 case T___builtin_expect:         return parse_builtin_expect();
4167                 case T___builtin_alloca:
4168                 case T___builtin_nan:
4169                 case T___builtin_nand:
4170                 case T___builtin_nanf:
4171                 case T___builtin_va_end:         return parse_builtin_symbol();
4172                 case T___builtin_isgreater:
4173                 case T___builtin_isgreaterequal:
4174                 case T___builtin_isless:
4175                 case T___builtin_islessequal:
4176                 case T___builtin_islessgreater:
4177                 case T___builtin_isunordered:    return parse_compare_builtin();
4178                 case T___builtin_constant_p:     return parse_builtin_constant();
4179                 case T___builtin_prefetch:       return parse_builtin_prefetch();
4180                 case T_assume:                   return parse_assume();
4181
4182                 case '(':                        return parse_brace_expression();
4183         }
4184
4185         errorf(HERE, "unexpected token %K, expected an expression", &token);
4186         eat_statement();
4187
4188         return create_invalid_expression();
4189 }
4190
4191 /**
4192  * Check if the expression has the character type and issue a warning then.
4193  */
4194 static void check_for_char_index_type(const expression_t *expression) {
4195         type_t       *const type      = expression->base.type;
4196         const type_t *const base_type = skip_typeref(type);
4197
4198         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
4199                         warning.char_subscripts) {
4200                 warningf(expression->base.source_position,
4201                         "array subscript has type '%T'", type);
4202         }
4203 }
4204
4205 static expression_t *parse_array_expression(unsigned precedence,
4206                                             expression_t *left)
4207 {
4208         (void) precedence;
4209
4210         eat('[');
4211
4212         expression_t *inside = parse_expression();
4213
4214         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
4215
4216         array_access_expression_t *array_access = &expression->array_access;
4217
4218         type_t *const orig_type_left   = left->base.type;
4219         type_t *const orig_type_inside = inside->base.type;
4220
4221         type_t *const type_left   = skip_typeref(orig_type_left);
4222         type_t *const type_inside = skip_typeref(orig_type_inside);
4223
4224         type_t *return_type;
4225         if (is_type_pointer(type_left)) {
4226                 return_type             = type_left->pointer.points_to;
4227                 array_access->array_ref = left;
4228                 array_access->index     = inside;
4229                 check_for_char_index_type(inside);
4230         } else if (is_type_pointer(type_inside)) {
4231                 return_type             = type_inside->pointer.points_to;
4232                 array_access->array_ref = inside;
4233                 array_access->index     = left;
4234                 array_access->flipped   = true;
4235                 check_for_char_index_type(left);
4236         } else {
4237                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
4238                         errorf(HERE,
4239                                 "array access on object with non-pointer types '%T', '%T'",
4240                                 orig_type_left, orig_type_inside);
4241                 }
4242                 return_type             = type_error_type;
4243                 array_access->array_ref = create_invalid_expression();
4244         }
4245
4246         if(token.type != ']') {
4247                 parse_error_expected("Problem while parsing array access", ']', 0);
4248                 return expression;
4249         }
4250         next_token();
4251
4252         return_type           = automatic_type_conversion(return_type);
4253         expression->base.type = return_type;
4254
4255         return expression;
4256 }
4257
4258 static expression_t *parse_typeprop(expression_kind_t kind, unsigned precedence)
4259 {
4260         expression_t *tp_expression = allocate_expression_zero(kind);
4261         tp_expression->base.type    = type_size_t;
4262
4263         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
4264                 next_token();
4265                 tp_expression->typeprop.type = parse_typename();
4266                 expect(')');
4267         } else {
4268                 expression_t *expression = parse_sub_expression(precedence);
4269                 expression->base.type    = revert_automatic_type_conversion(expression);
4270
4271                 tp_expression->typeprop.type          = expression->base.type;
4272                 tp_expression->typeprop.tp_expression = expression;
4273         }
4274
4275         return tp_expression;
4276 }
4277
4278 static expression_t *parse_sizeof(unsigned precedence)
4279 {
4280         eat(T_sizeof);
4281         return parse_typeprop(EXPR_SIZEOF, precedence);
4282 }
4283
4284 static expression_t *parse_alignof(unsigned precedence)
4285 {
4286         eat(T___alignof__);
4287         return parse_typeprop(EXPR_SIZEOF, precedence);
4288 }
4289
4290 static expression_t *parse_select_expression(unsigned precedence,
4291                                              expression_t *compound)
4292 {
4293         (void) precedence;
4294         assert(token.type == '.' || token.type == T_MINUSGREATER);
4295
4296         bool is_pointer = (token.type == T_MINUSGREATER);
4297         next_token();
4298
4299         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
4300         select->select.compound = compound;
4301
4302         if(token.type != T_IDENTIFIER) {
4303                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
4304                 return select;
4305         }
4306         symbol_t *symbol      = token.v.symbol;
4307         select->select.symbol = symbol;
4308         next_token();
4309
4310         type_t *const orig_type = compound->base.type;
4311         type_t *const type      = skip_typeref(orig_type);
4312
4313         type_t *type_left = type;
4314         if(is_pointer) {
4315                 if (!is_type_pointer(type)) {
4316                         if (is_type_valid(type)) {
4317                                 errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
4318                         }
4319                         return create_invalid_expression();
4320                 }
4321                 type_left = type->pointer.points_to;
4322         }
4323         type_left = skip_typeref(type_left);
4324
4325         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
4326             type_left->kind != TYPE_COMPOUND_UNION) {
4327                 if (is_type_valid(type_left)) {
4328                         errorf(HERE, "request for member '%Y' in something not a struct or "
4329                                "union, but '%T'", symbol, type_left);
4330                 }
4331                 return create_invalid_expression();
4332         }
4333
4334         declaration_t *const declaration = type_left->compound.declaration;
4335
4336         if(!declaration->init.is_defined) {
4337                 errorf(HERE, "request for member '%Y' of incomplete type '%T'",
4338                        symbol, type_left);
4339                 return create_invalid_expression();
4340         }
4341
4342         declaration_t *iter = find_compound_entry(declaration, symbol);
4343         if(iter == NULL) {
4344                 errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
4345                 return create_invalid_expression();
4346         }
4347
4348         /* we always do the auto-type conversions; the & and sizeof parser contains
4349          * code to revert this! */
4350         type_t *expression_type = automatic_type_conversion(iter->type);
4351
4352         select->select.compound_entry = iter;
4353         select->base.type             = expression_type;
4354
4355         if(expression_type->kind == TYPE_BITFIELD) {
4356                 expression_t *extract
4357                         = allocate_expression_zero(EXPR_UNARY_BITFIELD_EXTRACT);
4358                 extract->unary.value = select;
4359                 extract->base.type   = expression_type->bitfield.base;
4360
4361                 return extract;
4362         }
4363
4364         return select;
4365 }
4366
4367 /**
4368  * Parse a call expression, ie. expression '( ... )'.
4369  *
4370  * @param expression  the function address
4371  */
4372 static expression_t *parse_call_expression(unsigned precedence,
4373                                            expression_t *expression)
4374 {
4375         (void) precedence;
4376         expression_t *result = allocate_expression_zero(EXPR_CALL);
4377
4378         call_expression_t *call = &result->call;
4379         call->function          = expression;
4380
4381         type_t *const orig_type = expression->base.type;
4382         type_t *const type      = skip_typeref(orig_type);
4383
4384         function_type_t *function_type = NULL;
4385         if (is_type_pointer(type)) {
4386                 type_t *const to_type = skip_typeref(type->pointer.points_to);
4387
4388                 if (is_type_function(to_type)) {
4389                         function_type   = &to_type->function;
4390                         call->base.type = function_type->return_type;
4391                 }
4392         }
4393
4394         if (function_type == NULL && is_type_valid(type)) {
4395                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
4396         }
4397
4398         /* parse arguments */
4399         eat('(');
4400
4401         if(token.type != ')') {
4402                 call_argument_t *last_argument = NULL;
4403
4404                 while(true) {
4405                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
4406
4407                         argument->expression = parse_assignment_expression();
4408                         if(last_argument == NULL) {
4409                                 call->arguments = argument;
4410                         } else {
4411                                 last_argument->next = argument;
4412                         }
4413                         last_argument = argument;
4414
4415                         if(token.type != ',')
4416                                 break;
4417                         next_token();
4418                 }
4419         }
4420         expect(')');
4421
4422         if(function_type != NULL) {
4423                 function_parameter_t *parameter = function_type->parameters;
4424                 call_argument_t      *argument  = call->arguments;
4425                 for( ; parameter != NULL && argument != NULL;
4426                                 parameter = parameter->next, argument = argument->next) {
4427                         type_t *expected_type = parameter->type;
4428                         /* TODO report scope in error messages */
4429                         expression_t *const arg_expr = argument->expression;
4430                         type_t       *const res_type = semantic_assign(expected_type, arg_expr, "function call");
4431                         if (res_type == NULL) {
4432                                 /* TODO improve error message */
4433                                 errorf(arg_expr->base.source_position,
4434                                         "Cannot call function with argument '%E' of type '%T' where type '%T' is expected",
4435                                         arg_expr, arg_expr->base.type, expected_type);
4436                         } else {
4437                                 argument->expression = create_implicit_cast(argument->expression, expected_type);
4438                         }
4439                 }
4440                 /* too few parameters */
4441                 if(parameter != NULL) {
4442                         errorf(HERE, "too few arguments to function '%E'", expression);
4443                 } else if(argument != NULL) {
4444                         /* too many parameters */
4445                         if(!function_type->variadic
4446                                         && !function_type->unspecified_parameters) {
4447                                 errorf(HERE, "too many arguments to function '%E'", expression);
4448                         } else {
4449                                 /* do default promotion */
4450                                 for( ; argument != NULL; argument = argument->next) {
4451                                         type_t *type = argument->expression->base.type;
4452
4453                                         type = skip_typeref(type);
4454                                         if(is_type_integer(type)) {
4455                                                 type = promote_integer(type);
4456                                         } else if(type == type_float) {
4457                                                 type = type_double;
4458                                         }
4459
4460                                         argument->expression
4461                                                 = create_implicit_cast(argument->expression, type);
4462                                 }
4463
4464                                 check_format(&result->call);
4465                         }
4466                 } else {
4467                         check_format(&result->call);
4468                 }
4469         }
4470
4471         return result;
4472 }
4473
4474 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
4475
4476 static bool same_compound_type(const type_t *type1, const type_t *type2)
4477 {
4478         return
4479                 is_type_compound(type1) &&
4480                 type1->kind == type2->kind &&
4481                 type1->compound.declaration == type2->compound.declaration;
4482 }
4483
4484 /**
4485  * Parse a conditional expression, ie. 'expression ? ... : ...'.
4486  *
4487  * @param expression  the conditional expression
4488  */
4489 static expression_t *parse_conditional_expression(unsigned precedence,
4490                                                   expression_t *expression)
4491 {
4492         eat('?');
4493
4494         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
4495
4496         conditional_expression_t *conditional = &result->conditional;
4497         conditional->condition = expression;
4498
4499         /* 6.5.15.2 */
4500         type_t *const condition_type_orig = expression->base.type;
4501         type_t *const condition_type      = skip_typeref(condition_type_orig);
4502         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
4503                 type_error("expected a scalar type in conditional condition",
4504                            expression->base.source_position, condition_type_orig);
4505         }
4506
4507         expression_t *true_expression = parse_expression();
4508         expect(':');
4509         expression_t *false_expression = parse_sub_expression(precedence);
4510
4511         type_t *const orig_true_type  = true_expression->base.type;
4512         type_t *const orig_false_type = false_expression->base.type;
4513         type_t *const true_type       = skip_typeref(orig_true_type);
4514         type_t *const false_type      = skip_typeref(orig_false_type);
4515
4516         /* 6.5.15.3 */
4517         type_t *result_type;
4518         if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
4519                 result_type = semantic_arithmetic(true_type, false_type);
4520
4521                 true_expression  = create_implicit_cast(true_expression, result_type);
4522                 false_expression = create_implicit_cast(false_expression, result_type);
4523
4524                 conditional->true_expression  = true_expression;
4525                 conditional->false_expression = false_expression;
4526                 conditional->base.type        = result_type;
4527         } else if (same_compound_type(true_type, false_type) || (
4528             is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
4529             is_type_atomic(false_type, ATOMIC_TYPE_VOID)
4530                 )) {
4531                 /* just take 1 of the 2 types */
4532                 result_type = true_type;
4533         } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
4534                         && pointers_compatible(true_type, false_type)) {
4535                 /* ok */
4536                 result_type = true_type;
4537         } else if (is_type_pointer(true_type)
4538                         && is_null_pointer_constant(false_expression)) {
4539                 result_type = true_type;
4540         } else if (is_type_pointer(false_type)
4541                         && is_null_pointer_constant(true_expression)) {
4542                 result_type = false_type;
4543         } else {
4544                 /* TODO: one pointer to void*, other some pointer */
4545
4546                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
4547                         type_error_incompatible("while parsing conditional",
4548                                                 expression->base.source_position, true_type,
4549                                                 false_type);
4550                 }
4551                 result_type = type_error_type;
4552         }
4553
4554         conditional->true_expression
4555                 = create_implicit_cast(true_expression, result_type);
4556         conditional->false_expression
4557                 = create_implicit_cast(false_expression, result_type);
4558         conditional->base.type = result_type;
4559         return result;
4560 }
4561
4562 /**
4563  * Parse an extension expression.
4564  */
4565 static expression_t *parse_extension(unsigned precedence)
4566 {
4567         eat(T___extension__);
4568
4569         /* TODO enable extensions */
4570         expression_t *expression = parse_sub_expression(precedence);
4571         /* TODO disable extensions */
4572         return expression;
4573 }
4574
4575 static expression_t *parse_builtin_classify_type(const unsigned precedence)
4576 {
4577         eat(T___builtin_classify_type);
4578
4579         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
4580         result->base.type    = type_int;
4581
4582         expect('(');
4583         expression_t *expression = parse_sub_expression(precedence);
4584         expect(')');
4585         result->classify_type.type_expression = expression;
4586
4587         return result;
4588 }
4589
4590 static void semantic_incdec(unary_expression_t *expression)
4591 {
4592         type_t *const orig_type = expression->value->base.type;
4593         type_t *const type      = skip_typeref(orig_type);
4594         /* TODO !is_type_real && !is_type_pointer */
4595         if(!is_type_arithmetic(type) && type->kind != TYPE_POINTER) {
4596                 if (is_type_valid(type)) {
4597                         /* TODO: improve error message */
4598                         errorf(HERE, "operation needs an arithmetic or pointer type");
4599                 }
4600                 return;
4601         }
4602
4603         expression->base.type = orig_type;
4604 }
4605
4606 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
4607 {
4608         type_t *const orig_type = expression->value->base.type;
4609         type_t *const type      = skip_typeref(orig_type);
4610         if(!is_type_arithmetic(type)) {
4611                 if (is_type_valid(type)) {
4612                         /* TODO: improve error message */
4613                         errorf(HERE, "operation needs an arithmetic type");
4614                 }
4615                 return;
4616         }
4617
4618         expression->base.type = orig_type;
4619 }
4620
4621 static void semantic_unexpr_scalar(unary_expression_t *expression)
4622 {
4623         type_t *const orig_type = expression->value->base.type;
4624         type_t *const type      = skip_typeref(orig_type);
4625         if (!is_type_scalar(type)) {
4626                 if (is_type_valid(type)) {
4627                         errorf(HERE, "operand of ! must be of scalar type");
4628                 }
4629                 return;
4630         }
4631
4632         expression->base.type = orig_type;
4633 }
4634
4635 static void semantic_unexpr_integer(unary_expression_t *expression)
4636 {
4637         type_t *const orig_type = expression->value->base.type;
4638         type_t *const type      = skip_typeref(orig_type);
4639         if (!is_type_integer(type)) {
4640                 if (is_type_valid(type)) {
4641                         errorf(HERE, "operand of ~ must be of integer type");
4642                 }
4643                 return;
4644         }
4645
4646         expression->base.type = orig_type;
4647 }
4648
4649 static void semantic_dereference(unary_expression_t *expression)
4650 {
4651         type_t *const orig_type = expression->value->base.type;
4652         type_t *const type      = skip_typeref(orig_type);
4653         if(!is_type_pointer(type)) {
4654                 if (is_type_valid(type)) {
4655                         errorf(HERE, "Unary '*' needs pointer or arrray type, but type '%T' given", orig_type);
4656                 }
4657                 return;
4658         }
4659
4660         type_t *result_type   = type->pointer.points_to;
4661         result_type           = automatic_type_conversion(result_type);
4662         expression->base.type = result_type;
4663 }
4664
4665 /**
4666  * Check the semantic of the address taken expression.
4667  */
4668 static void semantic_take_addr(unary_expression_t *expression)
4669 {
4670         expression_t *value = expression->value;
4671         value->base.type    = revert_automatic_type_conversion(value);
4672
4673         type_t *orig_type = value->base.type;
4674         if(!is_type_valid(orig_type))
4675                 return;
4676
4677         if(value->kind == EXPR_REFERENCE) {
4678                 declaration_t *const declaration = value->reference.declaration;
4679                 if(declaration != NULL) {
4680                         if (declaration->storage_class == STORAGE_CLASS_REGISTER) {
4681                                 errorf(expression->base.source_position,
4682                                         "address of register variable '%Y' requested",
4683                                         declaration->symbol);
4684                         }
4685                         declaration->address_taken = 1;
4686                 }
4687         }
4688
4689         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
4690 }
4691
4692 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
4693 static expression_t *parse_##unexpression_type(unsigned precedence)            \
4694 {                                                                              \
4695         eat(token_type);                                                           \
4696                                                                                    \
4697         expression_t *unary_expression                                             \
4698                 = allocate_expression_zero(unexpression_type);                         \
4699         unary_expression->base.source_position = HERE;                             \
4700         unary_expression->unary.value = parse_sub_expression(precedence);          \
4701                                                                                    \
4702         sfunc(&unary_expression->unary);                                           \
4703                                                                                    \
4704         return unary_expression;                                                   \
4705 }
4706
4707 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
4708                                semantic_unexpr_arithmetic)
4709 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
4710                                semantic_unexpr_arithmetic)
4711 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
4712                                semantic_unexpr_scalar)
4713 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
4714                                semantic_dereference)
4715 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
4716                                semantic_take_addr)
4717 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
4718                                semantic_unexpr_integer)
4719 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
4720                                semantic_incdec)
4721 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
4722                                semantic_incdec)
4723
4724 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
4725                                                sfunc)                         \
4726 static expression_t *parse_##unexpression_type(unsigned precedence,           \
4727                                                expression_t *left)            \
4728 {                                                                             \
4729         (void) precedence;                                                        \
4730         eat(token_type);                                                          \
4731                                                                               \
4732         expression_t *unary_expression                                            \
4733                 = allocate_expression_zero(unexpression_type);                        \
4734         unary_expression->unary.value = left;                                     \
4735                                                                                   \
4736         sfunc(&unary_expression->unary);                                          \
4737                                                                               \
4738         return unary_expression;                                                  \
4739 }
4740
4741 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
4742                                        EXPR_UNARY_POSTFIX_INCREMENT,
4743                                        semantic_incdec)
4744 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
4745                                        EXPR_UNARY_POSTFIX_DECREMENT,
4746                                        semantic_incdec)
4747
4748 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
4749 {
4750         /* TODO: handle complex + imaginary types */
4751
4752         /* § 6.3.1.8 Usual arithmetic conversions */
4753         if(type_left == type_long_double || type_right == type_long_double) {
4754                 return type_long_double;
4755         } else if(type_left == type_double || type_right == type_double) {
4756                 return type_double;
4757         } else if(type_left == type_float || type_right == type_float) {
4758                 return type_float;
4759         }
4760
4761         type_right = promote_integer(type_right);
4762         type_left  = promote_integer(type_left);
4763
4764         if(type_left == type_right)
4765                 return type_left;
4766
4767         bool signed_left  = is_type_signed(type_left);
4768         bool signed_right = is_type_signed(type_right);
4769         int  rank_left    = get_rank(type_left);
4770         int  rank_right   = get_rank(type_right);
4771         if(rank_left < rank_right) {
4772                 if(signed_left == signed_right || !signed_right) {
4773                         return type_right;
4774                 } else {
4775                         return type_left;
4776                 }
4777         } else {
4778                 if(signed_left == signed_right || !signed_left) {
4779                         return type_left;
4780                 } else {
4781                         return type_right;
4782                 }
4783         }
4784 }
4785
4786 /**
4787  * Check the semantic restrictions for a binary expression.
4788  */
4789 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
4790 {
4791         expression_t *const left            = expression->left;
4792         expression_t *const right           = expression->right;
4793         type_t       *const orig_type_left  = left->base.type;
4794         type_t       *const orig_type_right = right->base.type;
4795         type_t       *const type_left       = skip_typeref(orig_type_left);
4796         type_t       *const type_right      = skip_typeref(orig_type_right);
4797
4798         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4799                 /* TODO: improve error message */
4800                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4801                         errorf(HERE, "operation needs arithmetic types");
4802                 }
4803                 return;
4804         }
4805
4806         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4807         expression->left      = create_implicit_cast(left, arithmetic_type);
4808         expression->right     = create_implicit_cast(right, arithmetic_type);
4809         expression->base.type = arithmetic_type;
4810 }
4811
4812 static void semantic_shift_op(binary_expression_t *expression)
4813 {
4814         expression_t *const left            = expression->left;
4815         expression_t *const right           = expression->right;
4816         type_t       *const orig_type_left  = left->base.type;
4817         type_t       *const orig_type_right = right->base.type;
4818         type_t       *      type_left       = skip_typeref(orig_type_left);
4819         type_t       *      type_right      = skip_typeref(orig_type_right);
4820
4821         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
4822                 /* TODO: improve error message */
4823                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4824                         errorf(HERE, "operation needs integer types");
4825                 }
4826                 return;
4827         }
4828
4829         type_left  = promote_integer(type_left);
4830         type_right = promote_integer(type_right);
4831
4832         expression->left      = create_implicit_cast(left, type_left);
4833         expression->right     = create_implicit_cast(right, type_right);
4834         expression->base.type = type_left;
4835 }
4836
4837 static void semantic_add(binary_expression_t *expression)
4838 {
4839         expression_t *const left            = expression->left;
4840         expression_t *const right           = expression->right;
4841         type_t       *const orig_type_left  = left->base.type;
4842         type_t       *const orig_type_right = right->base.type;
4843         type_t       *const type_left       = skip_typeref(orig_type_left);
4844         type_t       *const type_right      = skip_typeref(orig_type_right);
4845
4846         /* § 5.6.5 */
4847         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4848                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4849                 expression->left  = create_implicit_cast(left, arithmetic_type);
4850                 expression->right = create_implicit_cast(right, arithmetic_type);
4851                 expression->base.type = arithmetic_type;
4852                 return;
4853         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4854                 expression->base.type = type_left;
4855         } else if(is_type_pointer(type_right) && is_type_integer(type_left)) {
4856                 expression->base.type = type_right;
4857         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4858                 errorf(HERE, "invalid operands to binary + ('%T', '%T')", orig_type_left, orig_type_right);
4859         }
4860 }
4861
4862 static void semantic_sub(binary_expression_t *expression)
4863 {
4864         expression_t *const left            = expression->left;
4865         expression_t *const right           = expression->right;
4866         type_t       *const orig_type_left  = left->base.type;
4867         type_t       *const orig_type_right = right->base.type;
4868         type_t       *const type_left       = skip_typeref(orig_type_left);
4869         type_t       *const type_right      = skip_typeref(orig_type_right);
4870
4871         /* § 5.6.5 */
4872         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4873                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4874                 expression->left        = create_implicit_cast(left, arithmetic_type);
4875                 expression->right       = create_implicit_cast(right, arithmetic_type);
4876                 expression->base.type =  arithmetic_type;
4877                 return;
4878         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4879                 expression->base.type = type_left;
4880         } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
4881                 if(!pointers_compatible(type_left, type_right)) {
4882                         errorf(HERE,
4883                                "pointers to incompatible objects to binary '-' ('%T', '%T')",
4884                                orig_type_left, orig_type_right);
4885                 } else {
4886                         expression->base.type = type_ptrdiff_t;
4887                 }
4888         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4889                 errorf(HERE, "invalid operands to binary '-' ('%T', '%T')",
4890                        orig_type_left, orig_type_right);
4891         }
4892 }
4893
4894 /**
4895  * Check the semantics of comparison expressions.
4896  *
4897  * @param expression   The expression to check.
4898  */
4899 static void semantic_comparison(binary_expression_t *expression)
4900 {
4901         expression_t *left            = expression->left;
4902         expression_t *right           = expression->right;
4903         type_t       *orig_type_left  = left->base.type;
4904         type_t       *orig_type_right = right->base.type;
4905
4906         type_t *type_left  = skip_typeref(orig_type_left);
4907         type_t *type_right = skip_typeref(orig_type_right);
4908
4909         /* TODO non-arithmetic types */
4910         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4911                 if (warning.sign_compare &&
4912                     (expression->base.kind != EXPR_BINARY_EQUAL &&
4913                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
4914                     (is_type_signed(type_left) != is_type_signed(type_right))) {
4915                         warningf(expression->base.source_position,
4916                                  "comparison between signed and unsigned");
4917                 }
4918                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4919                 expression->left        = create_implicit_cast(left, arithmetic_type);
4920                 expression->right       = create_implicit_cast(right, arithmetic_type);
4921                 expression->base.type   = arithmetic_type;
4922                 if (warning.float_equal &&
4923                     (expression->base.kind == EXPR_BINARY_EQUAL ||
4924                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
4925                     is_type_float(arithmetic_type)) {
4926                         warningf(expression->base.source_position,
4927                                  "comparing floating point with == or != is unsafe");
4928                 }
4929         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
4930                 /* TODO check compatibility */
4931         } else if (is_type_pointer(type_left)) {
4932                 expression->right = create_implicit_cast(right, type_left);
4933         } else if (is_type_pointer(type_right)) {
4934                 expression->left = create_implicit_cast(left, type_right);
4935         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4936                 type_error_incompatible("invalid operands in comparison",
4937                                         expression->base.source_position,
4938                                         type_left, type_right);
4939         }
4940         expression->base.type = type_int;
4941 }
4942
4943 static void semantic_arithmetic_assign(binary_expression_t *expression)
4944 {
4945         expression_t *left            = expression->left;
4946         expression_t *right           = expression->right;
4947         type_t       *orig_type_left  = left->base.type;
4948         type_t       *orig_type_right = right->base.type;
4949
4950         type_t *type_left  = skip_typeref(orig_type_left);
4951         type_t *type_right = skip_typeref(orig_type_right);
4952
4953         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4954                 /* TODO: improve error message */
4955                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4956                         errorf(HERE, "operation needs arithmetic types");
4957                 }
4958                 return;
4959         }
4960
4961         /* combined instructions are tricky. We can't create an implicit cast on
4962          * the left side, because we need the uncasted form for the store.
4963          * The ast2firm pass has to know that left_type must be right_type
4964          * for the arithmetic operation and create a cast by itself */
4965         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4966         expression->right       = create_implicit_cast(right, arithmetic_type);
4967         expression->base.type   = type_left;
4968 }
4969
4970 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
4971 {
4972         expression_t *const left            = expression->left;
4973         expression_t *const right           = expression->right;
4974         type_t       *const orig_type_left  = left->base.type;
4975         type_t       *const orig_type_right = right->base.type;
4976         type_t       *const type_left       = skip_typeref(orig_type_left);
4977         type_t       *const type_right      = skip_typeref(orig_type_right);
4978
4979         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4980                 /* combined instructions are tricky. We can't create an implicit cast on
4981                  * the left side, because we need the uncasted form for the store.
4982                  * The ast2firm pass has to know that left_type must be right_type
4983                  * for the arithmetic operation and create a cast by itself */
4984                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
4985                 expression->right     = create_implicit_cast(right, arithmetic_type);
4986                 expression->base.type = type_left;
4987         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
4988                 expression->base.type = type_left;
4989         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4990                 errorf(HERE, "incompatible types '%T' and '%T' in assignment", orig_type_left, orig_type_right);
4991         }
4992 }
4993
4994 /**
4995  * Check the semantic restrictions of a logical expression.
4996  */
4997 static void semantic_logical_op(binary_expression_t *expression)
4998 {
4999         expression_t *const left            = expression->left;
5000         expression_t *const right           = expression->right;
5001         type_t       *const orig_type_left  = left->base.type;
5002         type_t       *const orig_type_right = right->base.type;
5003         type_t       *const type_left       = skip_typeref(orig_type_left);
5004         type_t       *const type_right      = skip_typeref(orig_type_right);
5005
5006         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
5007                 /* TODO: improve error message */
5008                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
5009                         errorf(HERE, "operation needs scalar types");
5010                 }
5011                 return;
5012         }
5013
5014         expression->base.type = type_int;
5015 }
5016
5017 /**
5018  * Checks if a compound type has constant fields.
5019  */
5020 static bool has_const_fields(const compound_type_t *type)
5021 {
5022         const scope_t       *scope       = &type->declaration->scope;
5023         const declaration_t *declaration = scope->declarations;
5024
5025         for (; declaration != NULL; declaration = declaration->next) {
5026                 if (declaration->namespc != NAMESPACE_NORMAL)
5027                         continue;
5028
5029                 const type_t *decl_type = skip_typeref(declaration->type);
5030                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
5031                         return true;
5032         }
5033         /* TODO */
5034         return false;
5035 }
5036
5037 /**
5038  * Check the semantic restrictions of a binary assign expression.
5039  */
5040 static void semantic_binexpr_assign(binary_expression_t *expression)
5041 {
5042         expression_t *left           = expression->left;
5043         type_t       *orig_type_left = left->base.type;
5044
5045         type_t *type_left = revert_automatic_type_conversion(left);
5046         type_left         = skip_typeref(orig_type_left);
5047
5048         /* must be a modifiable lvalue */
5049         if (is_type_array(type_left)) {
5050                 errorf(HERE, "cannot assign to arrays ('%E')", left);
5051                 return;
5052         }
5053         if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
5054                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
5055                        orig_type_left);
5056                 return;
5057         }
5058         if(is_type_incomplete(type_left)) {
5059                 errorf(HERE,
5060                        "left-hand side of assignment '%E' has incomplete type '%T'",
5061                        left, orig_type_left);
5062                 return;
5063         }
5064         if(is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
5065                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
5066                        left, orig_type_left);
5067                 return;
5068         }
5069
5070         type_t *const res_type = semantic_assign(orig_type_left, expression->right,
5071                                                  "assignment");
5072         if (res_type == NULL) {
5073                 errorf(expression->base.source_position,
5074                         "cannot assign to '%T' from '%T'",
5075                         orig_type_left, expression->right->base.type);
5076         } else {
5077                 expression->right = create_implicit_cast(expression->right, res_type);
5078         }
5079
5080         expression->base.type = orig_type_left;
5081 }
5082
5083 static bool expression_has_effect(const expression_t *const expr)
5084 {
5085         switch (expr->kind) {
5086                 case EXPR_UNKNOWN:                   break;
5087                 case EXPR_INVALID:                   break;
5088                 case EXPR_REFERENCE:                 return false;
5089                 case EXPR_CONST:                     return false;
5090                 case EXPR_CHAR_CONST:                return false;
5091                 case EXPR_STRING_LITERAL:            return false;
5092                 case EXPR_WIDE_STRING_LITERAL:       return false;
5093                 case EXPR_CALL: {
5094                         const call_expression_t *const call = &expr->call;
5095                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
5096                                 return true;
5097
5098                         switch (call->function->builtin_symbol.symbol->ID) {
5099                                 case T___builtin_va_end: return true;
5100                                 default:                 return false;
5101                         }
5102                 }
5103                 case EXPR_CONDITIONAL: {
5104                         const conditional_expression_t *const cond = &expr->conditional;
5105                         return
5106                                 expression_has_effect(cond->true_expression) &&
5107                                 expression_has_effect(cond->false_expression);
5108                 }
5109                 case EXPR_SELECT:                    return false;
5110                 case EXPR_ARRAY_ACCESS:              return false;
5111                 case EXPR_SIZEOF:                    return false;
5112                 case EXPR_CLASSIFY_TYPE:             return false;
5113                 case EXPR_ALIGNOF:                   return false;
5114
5115                 case EXPR_FUNCTION:                  return false;
5116                 case EXPR_PRETTY_FUNCTION:           return false;
5117                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
5118                 case EXPR_BUILTIN_CONSTANT_P:        return false;
5119                 case EXPR_BUILTIN_PREFETCH:          return true;
5120                 case EXPR_OFFSETOF:                  return false;
5121                 case EXPR_VA_START:                  return true;
5122                 case EXPR_VA_ARG:                    return true;
5123                 case EXPR_STATEMENT:                 return true; // TODO
5124                 case EXPR_COMPOUND_LITERAL:          return false;
5125
5126                 case EXPR_UNARY_NEGATE:              return false;
5127                 case EXPR_UNARY_PLUS:                return false;
5128                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
5129                 case EXPR_UNARY_NOT:                 return false;
5130                 case EXPR_UNARY_DEREFERENCE:         return false;
5131                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
5132                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
5133                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
5134                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
5135                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
5136                 case EXPR_UNARY_CAST: {
5137                         type_t *type = skip_typeref(expr->base.type);
5138                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
5139                 }
5140                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
5141                 case EXPR_UNARY_ASSUME:              return true;
5142                 case EXPR_UNARY_BITFIELD_EXTRACT:    return false;
5143
5144                 case EXPR_BINARY_ADD:                return false;
5145                 case EXPR_BINARY_SUB:                return false;
5146                 case EXPR_BINARY_MUL:                return false;
5147                 case EXPR_BINARY_DIV:                return false;
5148                 case EXPR_BINARY_MOD:                return false;
5149                 case EXPR_BINARY_EQUAL:              return false;
5150                 case EXPR_BINARY_NOTEQUAL:           return false;
5151                 case EXPR_BINARY_LESS:               return false;
5152                 case EXPR_BINARY_LESSEQUAL:          return false;
5153                 case EXPR_BINARY_GREATER:            return false;
5154                 case EXPR_BINARY_GREATEREQUAL:       return false;
5155                 case EXPR_BINARY_BITWISE_AND:        return false;
5156                 case EXPR_BINARY_BITWISE_OR:         return false;
5157                 case EXPR_BINARY_BITWISE_XOR:        return false;
5158                 case EXPR_BINARY_SHIFTLEFT:          return false;
5159                 case EXPR_BINARY_SHIFTRIGHT:         return false;
5160                 case EXPR_BINARY_ASSIGN:             return true;
5161                 case EXPR_BINARY_MUL_ASSIGN:         return true;
5162                 case EXPR_BINARY_DIV_ASSIGN:         return true;
5163                 case EXPR_BINARY_MOD_ASSIGN:         return true;
5164                 case EXPR_BINARY_ADD_ASSIGN:         return true;
5165                 case EXPR_BINARY_SUB_ASSIGN:         return true;
5166                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
5167                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
5168                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
5169                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
5170                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
5171                 case EXPR_BINARY_LOGICAL_AND:
5172                 case EXPR_BINARY_LOGICAL_OR:
5173                 case EXPR_BINARY_COMMA:
5174                         return expression_has_effect(expr->binary.right);
5175
5176                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
5177                 case EXPR_BINARY_ISGREATER:          return false;
5178                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
5179                 case EXPR_BINARY_ISLESS:             return false;
5180                 case EXPR_BINARY_ISLESSEQUAL:        return false;
5181                 case EXPR_BINARY_ISLESSGREATER:      return false;
5182                 case EXPR_BINARY_ISUNORDERED:        return false;
5183         }
5184
5185         panic("unexpected statement");
5186 }
5187
5188 static void semantic_comma(binary_expression_t *expression)
5189 {
5190         if (warning.unused_value) {
5191                 const expression_t *const left = expression->left;
5192                 if (!expression_has_effect(left)) {
5193                         warningf(left->base.source_position, "left-hand operand of comma expression has no effect");
5194                 }
5195         }
5196         expression->base.type = expression->right->base.type;
5197 }
5198
5199 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
5200 static expression_t *parse_##binexpression_type(unsigned precedence,      \
5201                                                 expression_t *left)       \
5202 {                                                                         \
5203         eat(token_type);                                                      \
5204         source_position_t pos = HERE;                                         \
5205                                                                           \
5206         expression_t *right = parse_sub_expression(precedence + lr);          \
5207                                                                           \
5208         expression_t *binexpr = allocate_expression_zero(binexpression_type); \
5209         binexpr->base.source_position = pos;                                  \
5210         binexpr->binary.left  = left;                                         \
5211         binexpr->binary.right = right;                                        \
5212         sfunc(&binexpr->binary);                                              \
5213                                                                           \
5214         return binexpr;                                                       \
5215 }
5216
5217 CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
5218 CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
5219 CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
5220 CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
5221 CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
5222 CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
5223 CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
5224 CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
5225 CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
5226
5227 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
5228                       semantic_comparison, 1)
5229 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
5230                       semantic_comparison, 1)
5231 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
5232                       semantic_comparison, 1)
5233 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
5234                       semantic_comparison, 1)
5235
5236 CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
5237                       semantic_binexpr_arithmetic, 1)
5238 CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
5239                       semantic_binexpr_arithmetic, 1)
5240 CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
5241                       semantic_binexpr_arithmetic, 1)
5242 CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
5243                       semantic_logical_op, 1)
5244 CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
5245                       semantic_logical_op, 1)
5246 CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
5247                       semantic_shift_op, 1)
5248 CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
5249                       semantic_shift_op, 1)
5250 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
5251                       semantic_arithmetic_addsubb_assign, 0)
5252 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
5253                       semantic_arithmetic_addsubb_assign, 0)
5254 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
5255                       semantic_arithmetic_assign, 0)
5256 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
5257                       semantic_arithmetic_assign, 0)
5258 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
5259                       semantic_arithmetic_assign, 0)
5260 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
5261                       semantic_arithmetic_assign, 0)
5262 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
5263                       semantic_arithmetic_assign, 0)
5264 CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
5265                       semantic_arithmetic_assign, 0)
5266 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
5267                       semantic_arithmetic_assign, 0)
5268 CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
5269                       semantic_arithmetic_assign, 0)
5270
5271 static expression_t *parse_sub_expression(unsigned precedence)
5272 {
5273         if(token.type < 0) {
5274                 return expected_expression_error();
5275         }
5276
5277         expression_parser_function_t *parser
5278                 = &expression_parsers[token.type];
5279         source_position_t             source_position = token.source_position;
5280         expression_t                 *left;
5281
5282         if(parser->parser != NULL) {
5283                 left = parser->parser(parser->precedence);
5284         } else {
5285                 left = parse_primary_expression();
5286         }
5287         assert(left != NULL);
5288         left->base.source_position = source_position;
5289
5290         while(true) {
5291                 if(token.type < 0) {
5292                         return expected_expression_error();
5293                 }
5294
5295                 parser = &expression_parsers[token.type];
5296                 if(parser->infix_parser == NULL)
5297                         break;
5298                 if(parser->infix_precedence < precedence)
5299                         break;
5300
5301                 left = parser->infix_parser(parser->infix_precedence, left);
5302
5303                 assert(left != NULL);
5304                 assert(left->kind != EXPR_UNKNOWN);
5305                 left->base.source_position = source_position;
5306         }
5307
5308         return left;
5309 }
5310
5311 /**
5312  * Parse an expression.
5313  */
5314 static expression_t *parse_expression(void)
5315 {
5316         return parse_sub_expression(1);
5317 }
5318
5319 /**
5320  * Register a parser for a prefix-like operator with given precedence.
5321  *
5322  * @param parser      the parser function
5323  * @param token_type  the token type of the prefix token
5324  * @param precedence  the precedence of the operator
5325  */
5326 static void register_expression_parser(parse_expression_function parser,
5327                                        int token_type, unsigned precedence)
5328 {
5329         expression_parser_function_t *entry = &expression_parsers[token_type];
5330
5331         if(entry->parser != NULL) {
5332                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
5333                 panic("trying to register multiple expression parsers for a token");
5334         }
5335         entry->parser     = parser;
5336         entry->precedence = precedence;
5337 }
5338
5339 /**
5340  * Register a parser for an infix operator with given precedence.
5341  *
5342  * @param parser      the parser function
5343  * @param token_type  the token type of the infix operator
5344  * @param precedence  the precedence of the operator
5345  */
5346 static void register_infix_parser(parse_expression_infix_function parser,
5347                 int token_type, unsigned precedence)
5348 {
5349         expression_parser_function_t *entry = &expression_parsers[token_type];
5350
5351         if(entry->infix_parser != NULL) {
5352                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
5353                 panic("trying to register multiple infix expression parsers for a "
5354                       "token");
5355         }
5356         entry->infix_parser     = parser;
5357         entry->infix_precedence = precedence;
5358 }
5359
5360 /**
5361  * Initialize the expression parsers.
5362  */
5363 static void init_expression_parsers(void)
5364 {
5365         memset(&expression_parsers, 0, sizeof(expression_parsers));
5366
5367         register_infix_parser(parse_array_expression,         '[',              30);
5368         register_infix_parser(parse_call_expression,          '(',              30);
5369         register_infix_parser(parse_select_expression,        '.',              30);
5370         register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
5371         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
5372                                                               T_PLUSPLUS,       30);
5373         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
5374                                                               T_MINUSMINUS,     30);
5375
5376         register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
5377         register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
5378         register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
5379         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
5380         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
5381         register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
5382         register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
5383         register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
5384         register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
5385         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
5386         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
5387         register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
5388         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
5389                                                     T_EXCLAMATIONMARKEQUAL, 13);
5390         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
5391         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
5392         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
5393         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
5394         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
5395         register_infix_parser(parse_conditional_expression,   '?',               7);
5396         register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
5397         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
5398         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
5399         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
5400         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
5401         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
5402         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
5403                                                                 T_LESSLESSEQUAL, 2);
5404         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
5405                                                           T_GREATERGREATEREQUAL, 2);
5406         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
5407                                                                      T_ANDEQUAL, 2);
5408         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
5409                                                                     T_PIPEEQUAL, 2);
5410         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
5411                                                                    T_CARETEQUAL, 2);
5412
5413         register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
5414
5415         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
5416         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
5417         register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
5418         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
5419         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
5420         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
5421         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
5422                                                                   T_PLUSPLUS,   25);
5423         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
5424                                                                   T_MINUSMINUS, 25);
5425         register_expression_parser(parse_sizeof,                      T_sizeof, 25);
5426         register_expression_parser(parse_alignof,                T___alignof__, 25);
5427         register_expression_parser(parse_extension,            T___extension__, 25);
5428         register_expression_parser(parse_builtin_classify_type,
5429                                                      T___builtin_classify_type, 25);
5430 }
5431
5432 /**
5433  * Parse a asm statement constraints specification.
5434  */
5435 static asm_constraint_t *parse_asm_constraints(void)
5436 {
5437         asm_constraint_t *result = NULL;
5438         asm_constraint_t *last   = NULL;
5439
5440         while(token.type == T_STRING_LITERAL || token.type == '[') {
5441                 asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
5442                 memset(constraint, 0, sizeof(constraint[0]));
5443
5444                 if(token.type == '[') {
5445                         eat('[');
5446                         if(token.type != T_IDENTIFIER) {
5447                                 parse_error_expected("while parsing asm constraint",
5448                                                      T_IDENTIFIER, 0);
5449                                 return NULL;
5450                         }
5451                         constraint->symbol = token.v.symbol;
5452
5453                         expect(']');
5454                 }
5455
5456                 constraint->constraints = parse_string_literals();
5457                 expect('(');
5458                 constraint->expression = parse_expression();
5459                 expect(')');
5460
5461                 if(last != NULL) {
5462                         last->next = constraint;
5463                 } else {
5464                         result = constraint;
5465                 }
5466                 last = constraint;
5467
5468                 if(token.type != ',')
5469                         break;
5470                 eat(',');
5471         }
5472
5473         return result;
5474 }
5475
5476 /**
5477  * Parse a asm statement clobber specification.
5478  */
5479 static asm_clobber_t *parse_asm_clobbers(void)
5480 {
5481         asm_clobber_t *result = NULL;
5482         asm_clobber_t *last   = NULL;
5483
5484         while(token.type == T_STRING_LITERAL) {
5485                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
5486                 clobber->clobber       = parse_string_literals();
5487
5488                 if(last != NULL) {
5489                         last->next = clobber;
5490                 } else {
5491                         result = clobber;
5492                 }
5493                 last = clobber;
5494
5495                 if(token.type != ',')
5496                         break;
5497                 eat(',');
5498         }
5499
5500         return result;
5501 }
5502
5503 /**
5504  * Parse an asm statement.
5505  */
5506 static statement_t *parse_asm_statement(void)
5507 {
5508         eat(T_asm);
5509
5510         statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
5511         statement->base.source_position = token.source_position;
5512
5513         asm_statement_t *asm_statement = &statement->asms;
5514
5515         if(token.type == T_volatile) {
5516                 next_token();
5517                 asm_statement->is_volatile = true;
5518         }
5519
5520         expect('(');
5521         asm_statement->asm_text = parse_string_literals();
5522
5523         if(token.type != ':')
5524                 goto end_of_asm;
5525         eat(':');
5526
5527         asm_statement->inputs = parse_asm_constraints();
5528         if(token.type != ':')
5529                 goto end_of_asm;
5530         eat(':');
5531
5532         asm_statement->outputs = parse_asm_constraints();
5533         if(token.type != ':')
5534                 goto end_of_asm;
5535         eat(':');
5536
5537         asm_statement->clobbers = parse_asm_clobbers();
5538
5539 end_of_asm:
5540         expect(')');
5541         expect(';');
5542         return statement;
5543 }
5544
5545 /**
5546  * Parse a case statement.
5547  */
5548 static statement_t *parse_case_statement(void)
5549 {
5550         eat(T_case);
5551
5552         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
5553
5554         statement->base.source_position  = token.source_position;
5555         statement->case_label.expression = parse_expression();
5556
5557         if (c_mode & _GNUC) {
5558                 if (token.type == T_DOTDOTDOT) {
5559                         next_token();
5560                         statement->case_label.end_range = parse_expression();
5561                 }
5562         }
5563
5564         expect(':');
5565
5566         if (! is_constant_expression(statement->case_label.expression)) {
5567                 errorf(statement->base.source_position,
5568                         "case label does not reduce to an integer constant");
5569         } else {
5570                 /* TODO: check if the case label is already known */
5571                 if (current_switch != NULL) {
5572                         /* link all cases into the switch statement */
5573                         if (current_switch->last_case == NULL) {
5574                                 current_switch->first_case =
5575                                 current_switch->last_case  = &statement->case_label;
5576                         } else {
5577                                 current_switch->last_case->next = &statement->case_label;
5578                         }
5579                 } else {
5580                         errorf(statement->base.source_position,
5581                                 "case label not within a switch statement");
5582                 }
5583         }
5584         statement->case_label.statement = parse_statement();
5585
5586         return statement;
5587 }
5588
5589 /**
5590  * Finds an existing default label of a switch statement.
5591  */
5592 static case_label_statement_t *
5593 find_default_label(const switch_statement_t *statement)
5594 {
5595         case_label_statement_t *label = statement->first_case;
5596         for ( ; label != NULL; label = label->next) {
5597                 if (label->expression == NULL)
5598                         return label;
5599         }
5600         return NULL;
5601 }
5602
5603 /**
5604  * Parse a default statement.
5605  */
5606 static statement_t *parse_default_statement(void)
5607 {
5608         eat(T_default);
5609
5610         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
5611
5612         statement->base.source_position = token.source_position;
5613
5614         expect(':');
5615         if (current_switch != NULL) {
5616                 const case_label_statement_t *def_label = find_default_label(current_switch);
5617                 if (def_label != NULL) {
5618                         errorf(HERE, "multiple default labels in one switch");
5619                         errorf(def_label->base.source_position,
5620                                 "this is the first default label");
5621                 } else {
5622                         /* link all cases into the switch statement */
5623                         if (current_switch->last_case == NULL) {
5624                                 current_switch->first_case =
5625                                         current_switch->last_case  = &statement->case_label;
5626                         } else {
5627                                 current_switch->last_case->next = &statement->case_label;
5628                         }
5629                 }
5630         } else {
5631                 errorf(statement->base.source_position,
5632                         "'default' label not within a switch statement");
5633         }
5634         statement->case_label.statement = parse_statement();
5635
5636         return statement;
5637 }
5638
5639 /**
5640  * Return the declaration for a given label symbol or create a new one.
5641  */
5642 static declaration_t *get_label(symbol_t *symbol)
5643 {
5644         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
5645         assert(current_function != NULL);
5646         /* if we found a label in the same function, then we already created the
5647          * declaration */
5648         if(candidate != NULL
5649                         && candidate->parent_scope == &current_function->scope) {
5650                 return candidate;
5651         }
5652
5653         /* otherwise we need to create a new one */
5654         declaration_t *const declaration = allocate_declaration_zero();
5655         declaration->namespc       = NAMESPACE_LABEL;
5656         declaration->symbol        = symbol;
5657
5658         label_push(declaration);
5659
5660         return declaration;
5661 }
5662
5663 /**
5664  * Parse a label statement.
5665  */
5666 static statement_t *parse_label_statement(void)
5667 {
5668         assert(token.type == T_IDENTIFIER);
5669         symbol_t *symbol = token.v.symbol;
5670         next_token();
5671
5672         declaration_t *label = get_label(symbol);
5673
5674         /* if source position is already set then the label is defined twice,
5675          * otherwise it was just mentioned in a goto so far */
5676         if(label->source_position.input_name != NULL) {
5677                 errorf(HERE, "duplicate label '%Y'", symbol);
5678                 errorf(label->source_position, "previous definition of '%Y' was here",
5679                        symbol);
5680         } else {
5681                 label->source_position = token.source_position;
5682         }
5683
5684         statement_t *statement = allocate_statement_zero(STATEMENT_LABEL);
5685
5686         statement->base.source_position = token.source_position;
5687         statement->label.label          = label;
5688
5689         eat(':');
5690
5691         if(token.type == '}') {
5692                 /* TODO only warn? */
5693                 errorf(HERE, "label at end of compound statement");
5694                 return statement;
5695         } else {
5696                 if (token.type == ';') {
5697                         /* eat an empty statement here, to avoid the warning about an empty
5698                          * after a label.  label:; is commonly used to have a label before
5699                          * a }. */
5700                         next_token();
5701                 } else {
5702                         statement->label.statement = parse_statement();
5703                 }
5704         }
5705
5706         /* remember the labels's in a list for later checking */
5707         if (label_last == NULL) {
5708                 label_first = &statement->label;
5709         } else {
5710                 label_last->next = &statement->label;
5711         }
5712         label_last = &statement->label;
5713
5714         return statement;
5715 }
5716
5717 /**
5718  * Parse an if statement.
5719  */
5720 static statement_t *parse_if(void)
5721 {
5722         eat(T_if);
5723
5724         statement_t *statement          = allocate_statement_zero(STATEMENT_IF);
5725         statement->base.source_position = token.source_position;
5726
5727         expect('(');
5728         statement->ifs.condition = parse_expression();
5729         expect(')');
5730
5731         statement->ifs.true_statement = parse_statement();
5732         if(token.type == T_else) {
5733                 next_token();
5734                 statement->ifs.false_statement = parse_statement();
5735         }
5736
5737         return statement;
5738 }
5739
5740 /**
5741  * Parse a switch statement.
5742  */
5743 static statement_t *parse_switch(void)
5744 {
5745         eat(T_switch);
5746
5747         statement_t *statement          = allocate_statement_zero(STATEMENT_SWITCH);
5748         statement->base.source_position = token.source_position;
5749
5750         expect('(');
5751         expression_t *const expr = parse_expression();
5752         type_t       *      type = skip_typeref(expr->base.type);
5753         if (is_type_integer(type)) {
5754                 type = promote_integer(type);
5755         } else if (is_type_valid(type)) {
5756                 errorf(expr->base.source_position,
5757                        "switch quantity is not an integer, but '%T'", type);
5758                 type = type_error_type;
5759         }
5760         statement->switchs.expression = create_implicit_cast(expr, type);
5761         expect(')');
5762
5763         switch_statement_t *rem = current_switch;
5764         current_switch          = &statement->switchs;
5765         statement->switchs.body = parse_statement();
5766         current_switch          = rem;
5767
5768         if (warning.switch_default
5769                         && find_default_label(&statement->switchs) == NULL) {
5770                 warningf(statement->base.source_position, "switch has no default case");
5771         }
5772
5773         return statement;
5774 }
5775
5776 static statement_t *parse_loop_body(statement_t *const loop)
5777 {
5778         statement_t *const rem = current_loop;
5779         current_loop = loop;
5780
5781         statement_t *const body = parse_statement();
5782
5783         current_loop = rem;
5784         return body;
5785 }
5786
5787 /**
5788  * Parse a while statement.
5789  */
5790 static statement_t *parse_while(void)
5791 {
5792         eat(T_while);
5793
5794         statement_t *statement          = allocate_statement_zero(STATEMENT_WHILE);
5795         statement->base.source_position = token.source_position;
5796
5797         expect('(');
5798         statement->whiles.condition = parse_expression();
5799         expect(')');
5800
5801         statement->whiles.body = parse_loop_body(statement);
5802
5803         return statement;
5804 }
5805
5806 /**
5807  * Parse a do statement.
5808  */
5809 static statement_t *parse_do(void)
5810 {
5811         eat(T_do);
5812
5813         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
5814
5815         statement->base.source_position = token.source_position;
5816
5817         statement->do_while.body = parse_loop_body(statement);
5818
5819         expect(T_while);
5820         expect('(');
5821         statement->do_while.condition = parse_expression();
5822         expect(')');
5823         expect(';');
5824
5825         return statement;
5826 }
5827
5828 /**
5829  * Parse a for statement.
5830  */
5831 static statement_t *parse_for(void)
5832 {
5833         eat(T_for);
5834
5835         statement_t *statement          = allocate_statement_zero(STATEMENT_FOR);
5836         statement->base.source_position = token.source_position;
5837
5838         expect('(');
5839
5840         int      top        = environment_top();
5841         scope_t *last_scope = scope;
5842         set_scope(&statement->fors.scope);
5843
5844         if(token.type != ';') {
5845                 if(is_declaration_specifier(&token, false)) {
5846                         parse_declaration(record_declaration);
5847                 } else {
5848                         expression_t *const init = parse_expression();
5849                         statement->fors.initialisation = init;
5850                         if (warning.unused_value  && !expression_has_effect(init)) {
5851                                 warningf(init->base.source_position, "initialisation of 'for'-statement has no effect");
5852                         }
5853                         expect(';');
5854                 }
5855         } else {
5856                 expect(';');
5857         }
5858
5859         if(token.type != ';') {
5860                 statement->fors.condition = parse_expression();
5861         }
5862         expect(';');
5863         if(token.type != ')') {
5864                 expression_t *const step = parse_expression();
5865                 statement->fors.step = step;
5866                 if (warning.unused_value  && !expression_has_effect(step)) {
5867                         warningf(step->base.source_position, "step of 'for'-statement has no effect");
5868                 }
5869         }
5870         expect(')');
5871         statement->fors.body = parse_loop_body(statement);
5872
5873         assert(scope == &statement->fors.scope);
5874         set_scope(last_scope);
5875         environment_pop_to(top);
5876
5877         return statement;
5878 }
5879
5880 /**
5881  * Parse a goto statement.
5882  */
5883 static statement_t *parse_goto(void)
5884 {
5885         eat(T_goto);
5886
5887         if(token.type != T_IDENTIFIER) {
5888                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
5889                 eat_statement();
5890                 return NULL;
5891         }
5892         symbol_t *symbol = token.v.symbol;
5893         next_token();
5894
5895         declaration_t *label = get_label(symbol);
5896
5897         statement_t *statement          = allocate_statement_zero(STATEMENT_GOTO);
5898         statement->base.source_position = token.source_position;
5899
5900         statement->gotos.label = label;
5901
5902         /* remember the goto's in a list for later checking */
5903         if (goto_last == NULL) {
5904                 goto_first = &statement->gotos;
5905         } else {
5906                 goto_last->next = &statement->gotos;
5907         }
5908         goto_last = &statement->gotos;
5909
5910         expect(';');
5911
5912         return statement;
5913 }
5914
5915 /**
5916  * Parse a continue statement.
5917  */
5918 static statement_t *parse_continue(void)
5919 {
5920         statement_t *statement;
5921         if (current_loop == NULL) {
5922                 errorf(HERE, "continue statement not within loop");
5923                 statement = NULL;
5924         } else {
5925                 statement = allocate_statement_zero(STATEMENT_CONTINUE);
5926
5927                 statement->base.source_position = token.source_position;
5928         }
5929
5930         eat(T_continue);
5931         expect(';');
5932
5933         return statement;
5934 }
5935
5936 /**
5937  * Parse a break statement.
5938  */
5939 static statement_t *parse_break(void)
5940 {
5941         statement_t *statement;
5942         if (current_switch == NULL && current_loop == NULL) {
5943                 errorf(HERE, "break statement not within loop or switch");
5944                 statement = NULL;
5945         } else {
5946                 statement = allocate_statement_zero(STATEMENT_BREAK);
5947
5948                 statement->base.source_position = token.source_position;
5949         }
5950
5951         eat(T_break);
5952         expect(';');
5953
5954         return statement;
5955 }
5956
5957 /**
5958  * Check if a given declaration represents a local variable.
5959  */
5960 static bool is_local_var_declaration(const declaration_t *declaration) {
5961         switch ((storage_class_tag_t) declaration->storage_class) {
5962         case STORAGE_CLASS_AUTO:
5963         case STORAGE_CLASS_REGISTER: {
5964                 const type_t *type = skip_typeref(declaration->type);
5965                 if(is_type_function(type)) {
5966                         return false;
5967                 } else {
5968                         return true;
5969                 }
5970         }
5971         default:
5972                 return false;
5973         }
5974 }
5975
5976 /**
5977  * Check if a given declaration represents a variable.
5978  */
5979 static bool is_var_declaration(const declaration_t *declaration) {
5980         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF)
5981                 return false;
5982
5983         const type_t *type = skip_typeref(declaration->type);
5984         return !is_type_function(type);
5985 }
5986
5987 /**
5988  * Check if a given expression represents a local variable.
5989  */
5990 static bool is_local_variable(const expression_t *expression)
5991 {
5992         if (expression->base.kind != EXPR_REFERENCE) {
5993                 return false;
5994         }
5995         const declaration_t *declaration = expression->reference.declaration;
5996         return is_local_var_declaration(declaration);
5997 }
5998
5999 /**
6000  * Check if a given expression represents a local variable and
6001  * return its declaration then, else return NULL.
6002  */
6003 declaration_t *expr_is_variable(const expression_t *expression)
6004 {
6005         if (expression->base.kind != EXPR_REFERENCE) {
6006                 return NULL;
6007         }
6008         declaration_t *declaration = expression->reference.declaration;
6009         if (is_var_declaration(declaration))
6010                 return declaration;
6011         return NULL;
6012 }
6013
6014 /**
6015  * Parse a return statement.
6016  */
6017 static statement_t *parse_return(void)
6018 {
6019         eat(T_return);
6020
6021         statement_t *statement          = allocate_statement_zero(STATEMENT_RETURN);
6022         statement->base.source_position = token.source_position;
6023
6024         expression_t *return_value = NULL;
6025         if(token.type != ';') {
6026                 return_value = parse_expression();
6027         }
6028         expect(';');
6029
6030         const type_t *const func_type = current_function->type;
6031         assert(is_type_function(func_type));
6032         type_t *const return_type = skip_typeref(func_type->function.return_type);
6033
6034         if(return_value != NULL) {
6035                 type_t *return_value_type = skip_typeref(return_value->base.type);
6036
6037                 if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
6038                                 && !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
6039                         warningf(statement->base.source_position,
6040                                  "'return' with a value, in function returning void");
6041                         return_value = NULL;
6042                 } else {
6043                         type_t *const res_type = semantic_assign(return_type,
6044                                 return_value, "'return'");
6045                         if (res_type == NULL) {
6046                                 errorf(statement->base.source_position,
6047                                        "cannot return something of type '%T' in function returning '%T'",
6048                                        return_value->base.type, return_type);
6049                         } else {
6050                                 return_value = create_implicit_cast(return_value, res_type);
6051                         }
6052                 }
6053                 /* check for returning address of a local var */
6054                 if (return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
6055                         const expression_t *expression = return_value->unary.value;
6056                         if (is_local_variable(expression)) {
6057                                 warningf(statement->base.source_position,
6058                                          "function returns address of local variable");
6059                         }
6060                 }
6061         } else {
6062                 if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
6063                         warningf(statement->base.source_position,
6064                                  "'return' without value, in function returning non-void");
6065                 }
6066         }
6067         statement->returns.value = return_value;
6068
6069         return statement;
6070 }
6071
6072 /**
6073  * Parse a declaration statement.
6074  */
6075 static statement_t *parse_declaration_statement(void)
6076 {
6077         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
6078
6079         statement->base.source_position = token.source_position;
6080
6081         declaration_t *before = last_declaration;
6082         parse_declaration(record_declaration);
6083
6084         if(before == NULL) {
6085                 statement->declaration.declarations_begin = scope->declarations;
6086         } else {
6087                 statement->declaration.declarations_begin = before->next;
6088         }
6089         statement->declaration.declarations_end = last_declaration;
6090
6091         return statement;
6092 }
6093
6094 /**
6095  * Parse an expression statement, ie. expr ';'.
6096  */
6097 static statement_t *parse_expression_statement(void)
6098 {
6099         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
6100
6101         statement->base.source_position  = token.source_position;
6102         expression_t *const expr         = parse_expression();
6103         statement->expression.expression = expr;
6104
6105         if (warning.unused_value  && !expression_has_effect(expr)) {
6106                 warningf(expr->base.source_position, "statement has no effect");
6107         }
6108
6109         expect(';');
6110
6111         return statement;
6112 }
6113
6114 /**
6115  * Parse a statement.
6116  */
6117 static statement_t *parse_statement(void)
6118 {
6119         statement_t   *statement = NULL;
6120
6121         /* declaration or statement */
6122         switch(token.type) {
6123         case T_asm:
6124                 statement = parse_asm_statement();
6125                 break;
6126
6127         case T_case:
6128                 statement = parse_case_statement();
6129                 break;
6130
6131         case T_default:
6132                 statement = parse_default_statement();
6133                 break;
6134
6135         case '{':
6136                 statement = parse_compound_statement();
6137                 break;
6138
6139         case T_if:
6140                 statement = parse_if();
6141                 break;
6142
6143         case T_switch:
6144                 statement = parse_switch();
6145                 break;
6146
6147         case T_while:
6148                 statement = parse_while();
6149                 break;
6150
6151         case T_do:
6152                 statement = parse_do();
6153                 break;
6154
6155         case T_for:
6156                 statement = parse_for();
6157                 break;
6158
6159         case T_goto:
6160                 statement = parse_goto();
6161                 break;
6162
6163         case T_continue:
6164                 statement = parse_continue();
6165                 break;
6166
6167         case T_break:
6168                 statement = parse_break();
6169                 break;
6170
6171         case T_return:
6172                 statement = parse_return();
6173                 break;
6174
6175         case ';':
6176                 if (warning.empty_statement) {
6177                         warningf(HERE, "statement is empty");
6178                 }
6179                 next_token();
6180                 statement = NULL;
6181                 break;
6182
6183         case T_IDENTIFIER:
6184                 if(look_ahead(1)->type == ':') {
6185                         statement = parse_label_statement();
6186                         break;
6187                 }
6188
6189                 if(is_typedef_symbol(token.v.symbol)) {
6190                         statement = parse_declaration_statement();
6191                         break;
6192                 }
6193
6194                 statement = parse_expression_statement();
6195                 break;
6196
6197         case T___extension__:
6198                 /* this can be a prefix to a declaration or an expression statement */
6199                 /* we simply eat it now and parse the rest with tail recursion */
6200                 do {
6201                         next_token();
6202                 } while(token.type == T___extension__);
6203                 statement = parse_statement();
6204                 break;
6205
6206         DECLARATION_START
6207                 statement = parse_declaration_statement();
6208                 break;
6209
6210         default:
6211                 statement = parse_expression_statement();
6212                 break;
6213         }
6214
6215         assert(statement == NULL
6216                         || statement->base.source_position.input_name != NULL);
6217
6218         return statement;
6219 }
6220
6221 /**
6222  * Parse a compound statement.
6223  */
6224 static statement_t *parse_compound_statement(void)
6225 {
6226         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
6227
6228         statement->base.source_position = token.source_position;
6229
6230         eat('{');
6231
6232         int      top        = environment_top();
6233         scope_t *last_scope = scope;
6234         set_scope(&statement->compound.scope);
6235
6236         statement_t *last_statement = NULL;
6237
6238         while(token.type != '}' && token.type != T_EOF) {
6239                 statement_t *sub_statement = parse_statement();
6240                 if(sub_statement == NULL)
6241                         continue;
6242
6243                 if(last_statement != NULL) {
6244                         last_statement->base.next = sub_statement;
6245                 } else {
6246                         statement->compound.statements = sub_statement;
6247                 }
6248
6249                 while(sub_statement->base.next != NULL)
6250                         sub_statement = sub_statement->base.next;
6251
6252                 last_statement = sub_statement;
6253         }
6254
6255         if(token.type == '}') {
6256                 next_token();
6257         } else {
6258                 errorf(statement->base.source_position,
6259                        "end of file while looking for closing '}'");
6260         }
6261
6262         assert(scope == &statement->compound.scope);
6263         set_scope(last_scope);
6264         environment_pop_to(top);
6265
6266         return statement;
6267 }
6268
6269 /**
6270  * Initialize builtin types.
6271  */
6272 static void initialize_builtin_types(void)
6273 {
6274         type_intmax_t    = make_global_typedef("__intmax_t__",      type_long_long);
6275         type_size_t      = make_global_typedef("__SIZE_TYPE__",     type_unsigned_long);
6276         type_ssize_t     = make_global_typedef("__SSIZE_TYPE__",    type_long);
6277         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
6278         type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
6279         type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
6280         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    type_int);
6281         type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
6282
6283         type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
6284         type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
6285         type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
6286         type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
6287 }
6288
6289 /**
6290  * Check for unused global static functions and variables
6291  */
6292 static void check_unused_globals(void)
6293 {
6294         if (!warning.unused_function && !warning.unused_variable)
6295                 return;
6296
6297         for (const declaration_t *decl = global_scope->declarations; decl != NULL; decl = decl->next) {
6298                 if (decl->used || decl->storage_class != STORAGE_CLASS_STATIC)
6299                         continue;
6300
6301                 type_t *const type = decl->type;
6302                 const char *s;
6303                 if (is_type_function(skip_typeref(type))) {
6304                         if (!warning.unused_function || decl->is_inline)
6305                                 continue;
6306
6307                         s = (decl->init.statement != NULL ? "defined" : "declared");
6308                 } else {
6309                         if (!warning.unused_variable)
6310                                 continue;
6311
6312                         s = "defined";
6313                 }
6314
6315                 warningf(decl->source_position, "'%#T' %s but not used",
6316                         type, decl->symbol, s);
6317         }
6318 }
6319
6320 /**
6321  * Parse a translation unit.
6322  */
6323 static translation_unit_t *parse_translation_unit(void)
6324 {
6325         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
6326
6327         assert(global_scope == NULL);
6328         global_scope = &unit->scope;
6329
6330         assert(scope == NULL);
6331         set_scope(&unit->scope);
6332
6333         initialize_builtin_types();
6334
6335         while(token.type != T_EOF) {
6336                 if (token.type == ';') {
6337                         /* TODO error in strict mode */
6338                         warningf(HERE, "stray ';' outside of function");
6339                         next_token();
6340                 } else {
6341                         parse_external_declaration();
6342                 }
6343         }
6344
6345         assert(scope == &unit->scope);
6346         scope          = NULL;
6347         last_declaration = NULL;
6348
6349         assert(global_scope == &unit->scope);
6350         check_unused_globals();
6351         global_scope = NULL;
6352
6353         return unit;
6354 }
6355
6356 /**
6357  * Parse the input.
6358  *
6359  * @return  the translation unit or NULL if errors occurred.
6360  */
6361 translation_unit_t *parse(void)
6362 {
6363         environment_stack = NEW_ARR_F(stack_entry_t, 0);
6364         label_stack       = NEW_ARR_F(stack_entry_t, 0);
6365         diagnostic_count  = 0;
6366         error_count       = 0;
6367         warning_count     = 0;
6368
6369         type_set_output(stderr);
6370         ast_set_output(stderr);
6371
6372         lookahead_bufpos = 0;
6373         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
6374                 next_token();
6375         }
6376         translation_unit_t *unit = parse_translation_unit();
6377
6378         DEL_ARR_F(environment_stack);
6379         DEL_ARR_F(label_stack);
6380
6381         if(error_count > 0)
6382                 return NULL;
6383
6384         return unit;
6385 }
6386
6387 /**
6388  * Initialize the parser.
6389  */
6390 void init_parser(void)
6391 {
6392         init_expression_parsers();
6393         obstack_init(&temp_obst);
6394
6395         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
6396         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
6397 }
6398
6399 /**
6400  * Terminate the parser.
6401  */
6402 void exit_parser(void)
6403 {
6404         obstack_free(&temp_obst, NULL);
6405 }