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      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_STRING_LITERAL]      = sizeof(string_literal_expression_t),
 202                 [EXPR_WIDE_STRING_LITERAL] = sizeof(wide_string_literal_expression_t),
 203                 [EXPR_CALL]                = sizeof(call_expression_t),
 204                 [EXPR_UNARY_FIRST]         = sizeof(unary_expression_t),
 205                 [EXPR_BINARY_FIRST]        = sizeof(binary_expression_t),
 206                 [EXPR_CONDITIONAL]         = sizeof(conditional_expression_t),
 207                 [EXPR_SELECT]              = sizeof(select_expression_t),
 208                 [EXPR_ARRAY_ACCESS]        = sizeof(array_access_expression_t),
 209                 [EXPR_SIZEOF]              = sizeof(typeprop_expression_t),
 210                 [EXPR_ALIGNOF]             = sizeof(typeprop_expression_t),
 211                 [EXPR_CLASSIFY_TYPE]       = sizeof(classify_type_expression_t),
 212                 [EXPR_FUNCTION]            = sizeof(string_literal_expression_t),
 213                 [EXPR_PRETTY_FUNCTION]     = sizeof(string_literal_expression_t),
 214                 [EXPR_BUILTIN_SYMBOL]      = sizeof(builtin_symbol_expression_t),
 215                 [EXPR_BUILTIN_CONSTANT_P]  = sizeof(builtin_constant_expression_t),
 216                 [EXPR_BUILTIN_PREFETCH]    = sizeof(builtin_prefetch_expression_t),
 217                 [EXPR_OFFSETOF]            = sizeof(offsetof_expression_t),
 218                 [EXPR_VA_START]            = sizeof(va_start_expression_t),
 219                 [EXPR_VA_ARG]              = sizeof(va_arg_expression_t),
 220                 [EXPR_STATEMENT]           = sizeof(statement_expression_t),
 221         };
 222         if(kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 223                 return sizes[EXPR_UNARY_FIRST];
 224         }
 225         if(kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 226                 return sizes[EXPR_BINARY_FIRST];
 227         }
 228         assert(kind <= sizeof(sizes) / sizeof(sizes[0]));
 229         assert(sizes[kind] != 0);
 230         return sizes[kind];
 231 }
 232
 233 /**
 234  * Allocate an expression node of given kind and initialize all
 235  * fields with zero.
 236  */
 237 static expression_t *allocate_expression_zero(expression_kind_t kind)
 238 {
 239         size_t        size = get_expression_struct_size(kind);
 240         expression_t *res  = allocate_ast_zero(size);
 241
 242         res->base.kind = kind;
 243         res->base.type = type_error_type;
 244         return res;
 245 }
 246
 247 /**
 248  * Returns the size of a type node.
 249  *
 250  * @param kind  the type kind
 251  */
 252 static size_t get_type_struct_size(type_kind_t kind)
 253 {
 254         static const size_t sizes[] = {
 255                 [TYPE_ATOMIC]          = sizeof(atomic_type_t),
 256                 [TYPE_BITFIELD]        = sizeof(bitfield_type_t),
 257                 [TYPE_COMPOUND_STRUCT] = sizeof(compound_type_t),
 258                 [TYPE_COMPOUND_UNION]  = sizeof(compound_type_t),
 259                 [TYPE_ENUM]            = sizeof(enum_type_t),
 260                 [TYPE_FUNCTION]        = sizeof(function_type_t),
 261                 [TYPE_POINTER]         = sizeof(pointer_type_t),
 262                 [TYPE_ARRAY]           = sizeof(array_type_t),
 263                 [TYPE_BUILTIN]         = sizeof(builtin_type_t),
 264                 [TYPE_TYPEDEF]         = sizeof(typedef_type_t),
 265                 [TYPE_TYPEOF]          = sizeof(typeof_type_t),
 266         };
 267         assert(sizeof(sizes) / sizeof(sizes[0]) == (int) TYPE_TYPEOF + 1);
 268         assert(kind <= TYPE_TYPEOF);
 269         assert(sizes[kind] != 0);
 270         return sizes[kind];
 271 }
 272
 273 /**
 274  * Allocate a type node of given kind and initialize all
 275  * fields with zero.
 276  */
 277 static type_t *allocate_type_zero(type_kind_t kind)
 278 {
 279         size_t  size = get_type_struct_size(kind);
 280         type_t *res  = obstack_alloc(type_obst, size);
 281         memset(res, 0, size);
 282
 283         res->base.kind = kind;
 284         return res;
 285 }
 286
 287 /**
 288  * Returns the size of an initializer node.
 289  *
 290  * @param kind  the initializer kind
 291  */
 292 static size_t get_initializer_size(initializer_kind_t kind)
 293 {
 294         static const size_t sizes[] = {
 295                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 296                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 297                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 298                 [INITIALIZER_LIST]        = sizeof(initializer_list_t)
 299         };
 300         assert(kind < sizeof(sizes) / sizeof(*sizes));
 301         assert(sizes[kind] != 0);
 302         return sizes[kind];
 303 }
 304
 305 /**
 306  * Allocate an initializer node of given kind and initialize all
 307  * fields with zero.
 308  */
 309 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 310 {
 311         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 312         result->kind          = kind;
 313
 314         return result;
 315 }
 316
 317 /**
 318  * Free a type from the type obstack.
 319  */
 320 static void free_type(void *type)
 321 {
 322         obstack_free(type_obst, type);
 323 }
 324
 325 /**
 326  * Returns the index of the top element of the environment stack.
 327  */
 328 static size_t environment_top(void)
 329 {
 330         return ARR_LEN(environment_stack);
 331 }
 332
 333 /**
 334  * Returns the index of the top element of the label stack.
 335  */
 336 static size_t label_top(void)
 337 {
 338         return ARR_LEN(label_stack);
 339 }
 340
 341
 342 /**
 343  * Return the next token.
 344  */
 345 static inline void next_token(void)
 346 {
 347         token                              = lookahead_buffer[lookahead_bufpos];
 348         lookahead_buffer[lookahead_bufpos] = lexer_token;
 349         lexer_next_token();
 350
 351         lookahead_bufpos = (lookahead_bufpos+1) % MAX_LOOKAHEAD;
 352
 353 #ifdef PRINT_TOKENS
 354         print_token(stderr, &token);
 355         fprintf(stderr, "\n");
 356 #endif
 357 }
 358
 359 /**
 360  * Return the next token with a given lookahead.
 361  */
 362 static inline const token_t *look_ahead(int num)
 363 {
 364         assert(num > 0 && num <= MAX_LOOKAHEAD);
 365         int pos = (lookahead_bufpos+num-1) % MAX_LOOKAHEAD;
 366         return &lookahead_buffer[pos];
 367 }
 368
 369 #define eat(token_type)  do { assert(token.type == token_type); next_token(); } while(0)
 370
 371 /**
 372  * Report a parse error because an expected token was not found.
 373  */
 374 static void parse_error_expected(const char *message, ...)
 375 {
 376         if(message != NULL) {
 377                 errorf(HERE, "%s", message);
 378         }
 379         va_list ap;
 380         va_start(ap, message);
 381         errorf(HERE, "got '%K', expected %#k", &token, &ap, ", ");
 382         va_end(ap);
 383 }
 384
 385 /**
 386  * Report a type error.
 387  */
 388 static void type_error(const char *msg, const source_position_t source_position,
 389                        type_t *type)
 390 {
 391         errorf(source_position, "%s, but found type '%T'", msg, type);
 392 }
 393
 394 /**
 395  * Report an incompatible type.
 396  */
 397 static void type_error_incompatible(const char *msg,
 398                 const source_position_t source_position, type_t *type1, type_t *type2)
 399 {
 400         errorf(source_position, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 401 }
 402
 403 /**
 404  * Eat an complete block, ie. '{ ... }'.
 405  */
 406 static void eat_block(void)
 407 {
 408         if(token.type == '{')
 409                 next_token();
 410
 411         while(token.type != '}') {
 412                 if(token.type == T_EOF)
 413                         return;
 414                 if(token.type == '{') {
 415                         eat_block();
 416                         continue;
 417                 }
 418                 next_token();
 419         }
 420         eat('}');
 421 }
 422
 423 /**
 424  * Eat a statement until an ';' token.
 425  */
 426 static void eat_statement(void)
 427 {
 428         while(token.type != ';') {
 429                 if(token.type == T_EOF)
 430                         return;
 431                 if(token.type == '}')
 432                         return;
 433                 if(token.type == '{') {
 434                         eat_block();
 435                         continue;
 436                 }
 437                 next_token();
 438         }
 439         eat(';');
 440 }
 441
 442 /**
 443  * Eat a parenthesed term, ie. '( ... )'.
 444  */
 445 static void eat_paren(void)
 446 {
 447         if(token.type == '(')
 448                 next_token();
 449
 450         while(token.type != ')') {
 451                 if(token.type == T_EOF)
 452                         return;
 453                 if(token.type == ')' || token.type == ';' || token.type == '}') {
 454                         return;
 455                 }
 456                 if(token.type == '(') {
 457                         eat_paren();
 458                         continue;
 459                 }
 460                 if(token.type == '{') {
 461                         eat_block();
 462                         continue;
 463                 }
 464                 next_token();
 465         }
 466         eat(')');
 467 }
 468
 469 #define expect(expected)                           \
 470     if(UNLIKELY(token.type != (expected))) {       \
 471         parse_error_expected(NULL, (expected), 0); \
 472         eat_statement();                           \
 473         return NULL;                               \
 474     }                                              \
 475     next_token();
 476
 477 #define expect_block(expected)                     \
 478     if(UNLIKELY(token.type != (expected))) {       \
 479         parse_error_expected(NULL, (expected), 0); \
 480         eat_block();                               \
 481         return NULL;                               \
 482     }                                              \
 483     next_token();
 484
 485 #define expect_void(expected)                      \
 486     if(UNLIKELY(token.type != (expected))) {       \
 487         parse_error_expected(NULL, (expected), 0); \
 488         eat_statement();                           \
 489         return;                                    \
 490     }                                              \
 491     next_token();
 492
 493 static void set_scope(scope_t *new_scope)
 494 {
 495         scope = new_scope;
 496
 497         last_declaration = new_scope->declarations;
 498         if(last_declaration != NULL) {
 499                 while(last_declaration->next != NULL) {
 500                         last_declaration = last_declaration->next;
 501                 }
 502         }
 503 }
 504
 505 /**
 506  * Search a symbol in a given namespace and returns its declaration or
 507  * NULL if this symbol was not found.
 508  */
 509 static declaration_t *get_declaration(const symbol_t *const symbol, const namespace_t namespc)
 510 {
 511         declaration_t *declaration = symbol->declaration;
 512         for( ; declaration != NULL; declaration = declaration->symbol_next) {
 513                 if(declaration->namespc == namespc)
 514                         return declaration;
 515         }
 516
 517         return NULL;
 518 }
 519
 520 /**
 521  * pushs an environment_entry on the environment stack and links the
 522  * corresponding symbol to the new entry
 523  */
 524 static void stack_push(stack_entry_t **stack_ptr, declaration_t *declaration)
 525 {
 526         symbol_t    *symbol    = declaration->symbol;
 527         namespace_t  namespc = (namespace_t)declaration->namespc;
 528
 529         /* remember old declaration */
 530         stack_entry_t entry;
 531         entry.symbol          = symbol;
 532         entry.old_declaration = symbol->declaration;
 533         entry.namespc         = (unsigned short) namespc;
 534         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 535
 536         /* replace/add declaration into declaration list of the symbol */
 537         if(symbol->declaration == NULL) {
 538                 symbol->declaration = declaration;
 539         } else {
 540                 declaration_t *iter_last = NULL;
 541                 declaration_t *iter      = symbol->declaration;
 542                 for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 543                         /* replace an entry? */
 544                         if(iter->namespc == namespc) {
 545                                 if(iter_last == NULL) {
 546                                         symbol->declaration = declaration;
 547                                 } else {
 548                                         iter_last->symbol_next = declaration;
 549                                 }
 550                                 declaration->symbol_next = iter->symbol_next;
 551                                 break;
 552                         }
 553                 }
 554                 if(iter == NULL) {
 555                         assert(iter_last->symbol_next == NULL);
 556                         iter_last->symbol_next = declaration;
 557                 }
 558         }
 559 }
 560
 561 static void environment_push(declaration_t *declaration)
 562 {
 563         assert(declaration->source_position.input_name != NULL);
 564         assert(declaration->parent_scope != NULL);
 565         stack_push(&environment_stack, declaration);
 566 }
 567
 568 static void label_push(declaration_t *declaration)
 569 {
 570         declaration->parent_scope = &current_function->scope;
 571         stack_push(&label_stack, declaration);
 572 }
 573
 574 /**
 575  * pops symbols from the environment stack until @p new_top is the top element
 576  */
 577 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 578 {
 579         stack_entry_t *stack = *stack_ptr;
 580         size_t         top   = ARR_LEN(stack);
 581         size_t         i;
 582
 583         assert(new_top <= top);
 584         if(new_top == top)
 585                 return;
 586
 587         for(i = top; i > new_top; --i) {
 588                 stack_entry_t *entry = &stack[i - 1];
 589
 590                 declaration_t *old_declaration = entry->old_declaration;
 591                 symbol_t      *symbol          = entry->symbol;
 592                 namespace_t    namespc         = (namespace_t)entry->namespc;
 593
 594                 /* replace/remove declaration */
 595                 declaration_t *declaration = symbol->declaration;
 596                 assert(declaration != NULL);
 597                 if(declaration->namespc == namespc) {
 598                         if(old_declaration == NULL) {
 599                                 symbol->declaration = declaration->symbol_next;
 600                         } else {
 601                                 symbol->declaration = old_declaration;
 602                         }
 603                 } else {
 604                         declaration_t *iter_last = declaration;
 605                         declaration_t *iter      = declaration->symbol_next;
 606                         for( ; iter != NULL; iter_last = iter, iter = iter->symbol_next) {
 607                                 /* replace an entry? */
 608                                 if(iter->namespc == namespc) {
 609                                         assert(iter_last != NULL);
 610                                         iter_last->symbol_next = old_declaration;
 611                                         old_declaration->symbol_next = iter->symbol_next;
 612                                         break;
 613                                 }
 614                         }
 615                         assert(iter != NULL);
 616                 }
 617         }
 618
 619         ARR_SHRINKLEN(*stack_ptr, (int) new_top);
 620 }
 621
 622 static void environment_pop_to(size_t new_top)
 623 {
 624         stack_pop_to(&environment_stack, new_top);
 625 }
 626
 627 static void label_pop_to(size_t new_top)
 628 {
 629         stack_pop_to(&label_stack, new_top);
 630 }
 631
 632
 633 static int get_rank(const type_t *type)
 634 {
 635         assert(!is_typeref(type));
 636         /* The C-standard allows promoting to int or unsigned int (see § 7.2.2
 637          * and esp. footnote 108). However we can't fold constants (yet), so we
 638          * can't decide whether unsigned int is possible, while int always works.
 639          * (unsigned int would be preferable when possible... for stuff like
 640          *  struct { enum { ... } bla : 4; } ) */
 641         if(type->kind == TYPE_ENUM)
 642                 return ATOMIC_TYPE_INT;
 643
 644         assert(type->kind == TYPE_ATOMIC);
 645         return type->atomic.akind;
 646 }
 647
 648 static type_t *promote_integer(type_t *type)
 649 {
 650         if(type->kind == TYPE_BITFIELD)
 651                 type = type->bitfield.base;
 652
 653         if(get_rank(type) < ATOMIC_TYPE_INT)
 654                 type = type_int;
 655
 656         return type;
 657 }
 658
 659 /**
 660  * Create a cast expression.
 661  *
 662  * @param expression  the expression to cast
 663  * @param dest_type   the destination type
 664  */
 665 static expression_t *create_cast_expression(expression_t *expression,
 666                                             type_t *dest_type)
 667 {
 668         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 669
 670         cast->unary.value = expression;
 671         cast->base.type   = dest_type;
 672
 673         return cast;
 674 }
 675
 676 /**
 677  * Check if a given expression represents the 0 pointer constant.
 678  */
 679 static bool is_null_pointer_constant(const expression_t *expression)
 680 {
 681         /* skip void* cast */
 682         if(expression->kind == EXPR_UNARY_CAST
 683                         || expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 684                 expression = expression->unary.value;
 685         }
 686
 687         /* TODO: not correct yet, should be any constant integer expression
 688          * which evaluates to 0 */
 689         if (expression->kind != EXPR_CONST)
 690                 return false;
 691
 692         type_t *const type = skip_typeref(expression->base.type);
 693         if (!is_type_integer(type))
 694                 return false;
 695
 696         return expression->conste.v.int_value == 0;
 697 }
 698
 699 /**
 700  * Create an implicit cast expression.
 701  *
 702  * @param expression  the expression to cast
 703  * @param dest_type   the destination type
 704  */
 705 static expression_t *create_implicit_cast(expression_t *expression,
 706                                           type_t *dest_type)
 707 {
 708         type_t *const source_type = expression->base.type;
 709
 710         if (source_type == dest_type)
 711                 return expression;
 712
 713         return create_cast_expression(expression, dest_type);
 714 }
 715
 716 /** Implements the rules from § 6.5.16.1 */
 717 static type_t *semantic_assign(type_t *orig_type_left,
 718                             const expression_t *const right,
 719                             const char *context)
 720 {
 721         type_t *const orig_type_right = right->base.type;
 722         type_t *const type_left       = skip_typeref(orig_type_left);
 723         type_t *const type_right      = skip_typeref(orig_type_right);
 724
 725         if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 726             (is_type_pointer(type_left) && is_null_pointer_constant(right)) ||
 727             (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 728                 && is_type_pointer(type_right))) {
 729                 return orig_type_left;
 730         }
 731
 732         if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
 733                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 734                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 735
 736                 /* the left type has all qualifiers from the right type */
 737                 unsigned missing_qualifiers
 738                         = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 739                 if(missing_qualifiers != 0) {
 740                         errorf(HERE, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointed-to type", type_left, context, type_right, missing_qualifiers);
 741                         return orig_type_left;
 742                 }
 743
 744                 points_to_left  = get_unqualified_type(points_to_left);
 745                 points_to_right = get_unqualified_type(points_to_right);
 746
 747                 if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID) ||
 748                                 is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
 749                         return orig_type_left;
 750                 }
 751
 752                 if (!types_compatible(points_to_left, points_to_right)) {
 753                         warningf(right->base.source_position,
 754                                 "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 755                                 orig_type_left, context, right, orig_type_right);
 756                 }
 757
 758                 return orig_type_left;
 759         }
 760
 761         if (is_type_compound(type_left)  && is_type_compound(type_right)) {
 762                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
 763                 type_t *const unqual_type_right = get_unqualified_type(type_right);
 764                 if (types_compatible(unqual_type_left, unqual_type_right)) {
 765                         return orig_type_left;
 766                 }
 767         }
 768
 769         if (!is_type_valid(type_left))
 770                 return type_left;
 771
 772         if (!is_type_valid(type_right))
 773                 return orig_type_right;
 774
 775         return NULL;
 776 }
 777
 778 static expression_t *parse_constant_expression(void)
 779 {
 780         /* start parsing at precedence 7 (conditional expression) */
 781         expression_t *result = parse_sub_expression(7);
 782
 783         if(!is_constant_expression(result)) {
 784                 errorf(result->base.source_position, "expression '%E' is not constant\n", result);
 785         }
 786
 787         return result;
 788 }
 789
 790 static expression_t *parse_assignment_expression(void)
 791 {
 792         /* start parsing at precedence 2 (assignment expression) */
 793         return parse_sub_expression(2);
 794 }
 795
 796 static type_t *make_global_typedef(const char *name, type_t *type)
 797 {
 798         symbol_t *const symbol       = symbol_table_insert(name);
 799
 800         declaration_t *const declaration = allocate_declaration_zero();
 801         declaration->namespc         = NAMESPACE_NORMAL;
 802         declaration->storage_class   = STORAGE_CLASS_TYPEDEF;
 803         declaration->type            = type;
 804         declaration->symbol          = symbol;
 805         declaration->source_position = builtin_source_position;
 806
 807         record_declaration(declaration);
 808
 809         type_t *typedef_type               = allocate_type_zero(TYPE_TYPEDEF);
 810         typedef_type->typedeft.declaration = declaration;
 811
 812         return typedef_type;
 813 }
 814
 815 static string_t parse_string_literals(void)
 816 {
 817         assert(token.type == T_STRING_LITERAL);
 818         string_t result = token.v.string;
 819
 820         next_token();
 821
 822         while (token.type == T_STRING_LITERAL) {
 823                 result = concat_strings(&result, &token.v.string);
 824                 next_token();
 825         }
 826
 827         return result;
 828 }
 829
 830 static void parse_attributes(void)
 831 {
 832         while(true) {
 833                 switch(token.type) {
 834                 case T___attribute__: {
 835                         next_token();
 836
 837                         expect_void('(');
 838                         int depth = 1;
 839                         while(depth > 0) {
 840                                 switch(token.type) {
 841                                 case T_EOF:
 842                                         errorf(HERE, "EOF while parsing attribute");
 843                                         break;
 844                                 case '(':
 845                                         next_token();
 846                                         depth++;
 847                                         break;
 848                                 case ')':
 849                                         next_token();
 850                                         depth--;
 851                                         break;
 852                                 default:
 853                                         next_token();
 854                                 }
 855                         }
 856                         break;
 857                 }
 858                 case T_asm:
 859                         next_token();
 860                         expect_void('(');
 861                         if(token.type != T_STRING_LITERAL) {
 862                                 parse_error_expected("while parsing assembler attribute",
 863                                                      T_STRING_LITERAL);
 864                                 eat_paren();
 865                                 break;
 866                         } else {
 867                                 parse_string_literals();
 868                         }
 869                         expect_void(')');
 870                         break;
 871                 default:
 872                         goto attributes_finished;
 873                 }
 874         }
 875
 876 attributes_finished:
 877         ;
 878 }
 879
 880 #if 0
 881 static designator_t *parse_designation(void)
 882 {
 883         if(token.type != '[' && token.type != '.')
 884                 return NULL;
 885
 886         designator_t *result = NULL;
 887         designator_t *last   = NULL;
 888
 889         while(1) {
 890                 designator_t *designator;
 891                 switch(token.type) {
 892                 case '[':
 893                         designator = allocate_ast_zero(sizeof(designator[0]));
 894                         next_token();
 895                         designator->array_access = parse_constant_expression();
 896                         expect(']');
 897                         break;
 898                 case '.':
 899                         designator = allocate_ast_zero(sizeof(designator[0]));
 900                         next_token();
 901                         if(token.type != T_IDENTIFIER) {
 902                                 parse_error_expected("while parsing designator",
 903                                                      T_IDENTIFIER, 0);
 904                                 return NULL;
 905                         }
 906                         designator->symbol = token.v.symbol;
 907                         next_token();
 908                         break;
 909                 default:
 910                         expect('=');
 911                         return result;
 912                 }
 913
 914                 assert(designator != NULL);
 915                 if(last != NULL) {
 916                         last->next = designator;
 917                 } else {
 918                         result = designator;
 919                 }
 920                 last = designator;
 921         }
 922 }
 923 #endif
 924
 925 static initializer_t *initializer_from_string(array_type_t *type,
 926                                               const string_t *const string)
 927 {
 928         /* TODO: check len vs. size of array type */
 929         (void) type;
 930
 931         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
 932         initializer->string.string = *string;
 933
 934         return initializer;
 935 }
 936
 937 static initializer_t *initializer_from_wide_string(array_type_t *const type,
 938                                                    wide_string_t *const string)
 939 {
 940         /* TODO: check len vs. size of array type */
 941         (void) type;
 942
 943         initializer_t *const initializer =
 944                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
 945         initializer->wide_string.string = *string;
 946
 947         return initializer;
 948 }
 949
 950 static initializer_t *initializer_from_expression(type_t *type,
 951                                                   expression_t *expression)
 952 {
 953         /* TODO check that expression is a constant expression */
 954
 955         /* § 6.7.8.14/15 char array may be initialized by string literals */
 956         type_t *const expr_type = expression->base.type;
 957         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
 958                 array_type_t *const array_type   = &type->array;
 959                 type_t       *const element_type = skip_typeref(array_type->element_type);
 960
 961                 if (element_type->kind == TYPE_ATOMIC) {
 962                         switch (expression->kind) {
 963                                 case EXPR_STRING_LITERAL:
 964                                         if (element_type->atomic.akind == ATOMIC_TYPE_CHAR) {
 965                                                 return initializer_from_string(array_type,
 966                                                         &expression->string.value);
 967                                         }
 968
 969                                 case EXPR_WIDE_STRING_LITERAL: {
 970                                         type_t *bare_wchar_type = skip_typeref(type_wchar_t);
 971                                         if (get_unqualified_type(element_type) == bare_wchar_type) {
 972                                                 return initializer_from_wide_string(array_type,
 973                                                         &expression->wide_string.value);
 974                                         }
 975                                 }
 976
 977                                 default:
 978                                         break;
 979                         }
 980                 }
 981         }
 982
 983         type_t *const res_type = semantic_assign(type, expression, "initializer");
 984         if (res_type == NULL)
 985                 return NULL;
 986
 987         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
 988         result->value.value = create_implicit_cast(expression, res_type);
 989
 990         return result;
 991 }
 992
 993 static initializer_t *parse_sub_initializer(type_t *type,
 994                                             expression_t *expression);
 995
 996 static initializer_t *parse_sub_initializer_elem(type_t *type)
 997 {
 998         if(token.type == '{') {
 999                 return parse_sub_initializer(type, NULL);
1000         }
1001
1002         expression_t *expression = parse_assignment_expression();
1003         return parse_sub_initializer(type, expression);
1004 }
1005
1006 static bool had_initializer_brace_warning;
1007
1008 static void skip_designator(void)
1009 {
1010         while(1) {
1011                 if(token.type == '.') {
1012                         next_token();
1013                         if(token.type == T_IDENTIFIER)
1014                                 next_token();
1015                 } else if(token.type == '[') {
1016                         next_token();
1017                         parse_constant_expression();
1018                         if(token.type == ']')
1019                                 next_token();
1020                 } else {
1021                         break;
1022                 }
1023         }
1024 }
1025
1026 static initializer_t *parse_sub_initializer(type_t *type,
1027                                             expression_t *expression)
1028 {
1029         if(is_type_scalar(type)) {
1030                 /* there might be extra {} hierarchies */
1031                 if(token.type == '{') {
1032                         next_token();
1033                         if(!had_initializer_brace_warning) {
1034                                 warningf(HERE, "braces around scalar initializer");
1035                                 had_initializer_brace_warning = true;
1036                         }
1037                         initializer_t *result = parse_sub_initializer(type, NULL);
1038                         if(token.type == ',') {
1039                                 next_token();
1040                                 /* TODO: warn about excessive elements */
1041                         }
1042                         expect_block('}');
1043                         return result;
1044                 }
1045
1046                 if(expression == NULL) {
1047                         expression = parse_assignment_expression();
1048                 }
1049                 return initializer_from_expression(type, expression);
1050         }
1051
1052         /* does the expression match the currently looked at object to initialize */
1053         if(expression != NULL) {
1054                 initializer_t *result = initializer_from_expression(type, expression);
1055                 if(result != NULL)
1056                         return result;
1057         }
1058
1059         bool read_paren = false;
1060         if(token.type == '{') {
1061                 next_token();
1062                 read_paren = true;
1063         }
1064
1065         /* descend into subtype */
1066         initializer_t  *result = NULL;
1067         initializer_t **elems;
1068         if(is_type_array(type)) {
1069                 if(token.type == '.') {
1070                         errorf(HERE,
1071                                "compound designator in initializer for array type '%T'",
1072                                type);
1073                         skip_designator();
1074                 }
1075
1076                 type_t *const element_type = skip_typeref(type->array.element_type);
1077
1078                 initializer_t *sub;
1079                 had_initializer_brace_warning = false;
1080                 if(expression == NULL) {
1081                         sub = parse_sub_initializer_elem(element_type);
1082                 } else {
1083                         sub = parse_sub_initializer(element_type, expression);
1084                 }
1085
1086                 /* didn't match the subtypes -> try the parent type */
1087                 if(sub == NULL) {
1088                         assert(!read_paren);
1089                         return NULL;
1090                 }
1091
1092                 elems = NEW_ARR_F(initializer_t*, 0);
1093                 ARR_APP1(initializer_t*, elems, sub);
1094
1095                 while(true) {
1096                         if(token.type == '}')
1097                                 break;
1098                         expect_block(',');
1099                         if(token.type == '}')
1100                                 break;
1101
1102                         sub = parse_sub_initializer_elem(element_type);
1103                         if(sub == NULL) {
1104                                 /* TODO error, do nicer cleanup */
1105                                 errorf(HERE, "member initializer didn't match");
1106                                 DEL_ARR_F(elems);
1107                                 return NULL;
1108                         }
1109                         ARR_APP1(initializer_t*, elems, sub);
1110                 }
1111         } else {
1112                 assert(is_type_compound(type));
1113                 scope_t *const scope = &type->compound.declaration->scope;
1114
1115                 if(token.type == '[') {
1116                         errorf(HERE,
1117                                "array designator in initializer for compound type '%T'",
1118                                type);
1119                         skip_designator();
1120                 }
1121
1122                 declaration_t *first = scope->declarations;
1123                 if(first == NULL)
1124                         return NULL;
1125                 type_t *first_type = first->type;
1126                 first_type         = skip_typeref(first_type);
1127
1128                 initializer_t *sub;
1129                 had_initializer_brace_warning = false;
1130                 if(expression == NULL) {
1131                         sub = parse_sub_initializer_elem(first_type);
1132                 } else {
1133                         sub = parse_sub_initializer(first_type, expression);
1134                 }
1135
1136                 /* didn't match the subtypes -> try our parent type */
1137                 if(sub == NULL) {
1138                         assert(!read_paren);
1139                         return NULL;
1140                 }
1141
1142                 elems = NEW_ARR_F(initializer_t*, 0);
1143                 ARR_APP1(initializer_t*, elems, sub);
1144
1145                 declaration_t *iter  = first->next;
1146                 for( ; iter != NULL; iter = iter->next) {
1147                         if(iter->symbol == NULL)
1148                                 continue;
1149                         if(iter->namespc != NAMESPACE_NORMAL)
1150                                 continue;
1151
1152                         if(token.type == '}')
1153                                 break;
1154                         expect_block(',');
1155                         if(token.type == '}')
1156                                 break;
1157
1158                         type_t *iter_type = iter->type;
1159                         iter_type         = skip_typeref(iter_type);
1160
1161                         sub = parse_sub_initializer_elem(iter_type);
1162                         if(sub == NULL) {
1163                                 /* TODO error, do nicer cleanup */
1164                                 errorf(HERE, "member initializer didn't match");
1165                                 DEL_ARR_F(elems);
1166                                 return NULL;
1167                         }
1168                         ARR_APP1(initializer_t*, elems, sub);
1169                 }
1170         }
1171
1172         int    len        = ARR_LEN(elems);
1173         size_t elems_size = sizeof(initializer_t*) * len;
1174
1175         initializer_list_t *init = allocate_ast_zero(sizeof(init[0]) + elems_size);
1176
1177         init->initializer.kind = INITIALIZER_LIST;
1178         init->len              = len;
1179         memcpy(init->initializers, elems, elems_size);
1180         DEL_ARR_F(elems);
1181
1182         result = (initializer_t*) init;
1183
1184         if(read_paren) {
1185                 if(token.type == ',')
1186                         next_token();
1187                 expect('}');
1188         }
1189         return result;
1190 }
1191
1192 static initializer_t *parse_initializer(type_t *const orig_type)
1193 {
1194         initializer_t *result;
1195
1196         type_t *const type = skip_typeref(orig_type);
1197
1198         if(token.type != '{') {
1199                 expression_t  *expression  = parse_assignment_expression();
1200                 initializer_t *initializer = initializer_from_expression(type, expression);
1201                 if(initializer == NULL) {
1202                         errorf(HERE,
1203                                 "initializer expression '%E' of type '%T' is incompatible with type '%T'",
1204                                 expression, expression->base.type, orig_type);
1205                 }
1206                 return initializer;
1207         }
1208
1209         if(is_type_scalar(type)) {
1210                 /* § 6.7.8.11 */
1211                 eat('{');
1212
1213                 expression_t *expression = parse_assignment_expression();
1214                 result = initializer_from_expression(type, expression);
1215
1216                 if(token.type == ',')
1217                         next_token();
1218
1219                 expect('}');
1220                 return result;
1221         } else {
1222                 result = parse_sub_initializer(type, NULL);
1223         }
1224
1225         return result;
1226 }
1227
1228 static declaration_t *append_declaration(declaration_t *declaration);
1229
1230 static declaration_t *parse_compound_type_specifier(bool is_struct)
1231 {
1232         if(is_struct) {
1233                 eat(T_struct);
1234         } else {
1235                 eat(T_union);
1236         }
1237
1238         symbol_t      *symbol      = NULL;
1239         declaration_t *declaration = NULL;
1240
1241         if (token.type == T___attribute__) {
1242                 /* TODO */
1243                 parse_attributes();
1244         }
1245
1246         if(token.type == T_IDENTIFIER) {
1247                 symbol = token.v.symbol;
1248                 next_token();
1249
1250                 if(is_struct) {
1251                         declaration = get_declaration(symbol, NAMESPACE_STRUCT);
1252                 } else {
1253                         declaration = get_declaration(symbol, NAMESPACE_UNION);
1254                 }
1255         } else if(token.type != '{') {
1256                 if(is_struct) {
1257                         parse_error_expected("while parsing struct type specifier",
1258                                              T_IDENTIFIER, '{', 0);
1259                 } else {
1260                         parse_error_expected("while parsing union type specifier",
1261                                              T_IDENTIFIER, '{', 0);
1262                 }
1263
1264                 return NULL;
1265         }
1266
1267         if(declaration == NULL) {
1268                 declaration = allocate_declaration_zero();
1269                 declaration->namespc         =
1270                         (is_struct ? NAMESPACE_STRUCT : NAMESPACE_UNION);
1271                 declaration->source_position = token.source_position;
1272                 declaration->symbol          = symbol;
1273                 declaration->parent_scope  = scope;
1274                 if (symbol != NULL) {
1275                         environment_push(declaration);
1276                 }
1277                 append_declaration(declaration);
1278         }
1279
1280         if(token.type == '{') {
1281                 if(declaration->init.is_defined) {
1282                         assert(symbol != NULL);
1283                         errorf(HERE, "multiple definitions of '%s %Y'",
1284                                is_struct ? "struct" : "union", symbol);
1285                         declaration->scope.declarations = NULL;
1286                 }
1287                 declaration->init.is_defined = true;
1288
1289                 parse_compound_type_entries(declaration);
1290                 parse_attributes();
1291         }
1292
1293         return declaration;
1294 }
1295
1296 static void parse_enum_entries(type_t *const enum_type)
1297 {
1298         eat('{');
1299
1300         if(token.type == '}') {
1301                 next_token();
1302                 errorf(HERE, "empty enum not allowed");
1303                 return;
1304         }
1305
1306         do {
1307                 if(token.type != T_IDENTIFIER) {
1308                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, 0);
1309                         eat_block();
1310                         return;
1311                 }
1312
1313                 declaration_t *const entry = allocate_declaration_zero();
1314                 entry->storage_class   = STORAGE_CLASS_ENUM_ENTRY;
1315                 entry->type            = enum_type;
1316                 entry->symbol          = token.v.symbol;
1317                 entry->source_position = token.source_position;
1318                 next_token();
1319
1320                 if(token.type == '=') {
1321                         next_token();
1322                         entry->init.enum_value = parse_constant_expression();
1323
1324                         /* TODO semantic */
1325                 }
1326
1327                 record_declaration(entry);
1328
1329                 if(token.type != ',')
1330                         break;
1331                 next_token();
1332         } while(token.type != '}');
1333
1334         expect_void('}');
1335 }
1336
1337 static type_t *parse_enum_specifier(void)
1338 {
1339         eat(T_enum);
1340
1341         declaration_t *declaration;
1342         symbol_t      *symbol;
1343
1344         if(token.type == T_IDENTIFIER) {
1345                 symbol = token.v.symbol;
1346                 next_token();
1347
1348                 declaration = get_declaration(symbol, NAMESPACE_ENUM);
1349         } else if(token.type != '{') {
1350                 parse_error_expected("while parsing enum type specifier",
1351                                      T_IDENTIFIER, '{', 0);
1352                 return NULL;
1353         } else {
1354                 declaration = NULL;
1355                 symbol      = NULL;
1356         }
1357
1358         if(declaration == NULL) {
1359                 declaration = allocate_declaration_zero();
1360                 declaration->namespc         = NAMESPACE_ENUM;
1361                 declaration->source_position = token.source_position;
1362                 declaration->symbol          = symbol;
1363                 declaration->parent_scope  = scope;
1364         }
1365
1366         type_t *const type      = allocate_type_zero(TYPE_ENUM);
1367         type->enumt.declaration = declaration;
1368
1369         if(token.type == '{') {
1370                 if(declaration->init.is_defined) {
1371                         errorf(HERE, "multiple definitions of enum %Y", symbol);
1372                 }
1373                 if (symbol != NULL) {
1374                         environment_push(declaration);
1375                 }
1376                 append_declaration(declaration);
1377                 declaration->init.is_defined = 1;
1378
1379                 parse_enum_entries(type);
1380                 parse_attributes();
1381         }
1382
1383         return type;
1384 }
1385
1386 /**
1387  * if a symbol is a typedef to another type, return true
1388  */
1389 static bool is_typedef_symbol(symbol_t *symbol)
1390 {
1391         const declaration_t *const declaration =
1392                 get_declaration(symbol, NAMESPACE_NORMAL);
1393         return
1394                 declaration != NULL &&
1395                 declaration->storage_class == STORAGE_CLASS_TYPEDEF;
1396 }
1397
1398 static type_t *parse_typeof(void)
1399 {
1400         eat(T___typeof__);
1401
1402         type_t *type;
1403
1404         expect('(');
1405
1406         expression_t *expression  = NULL;
1407
1408 restart:
1409         switch(token.type) {
1410         case T___extension__:
1411                 /* this can be a prefix to a typename or an expression */
1412                 /* we simply eat it now. */
1413                 do {
1414                         next_token();
1415                 } while(token.type == T___extension__);
1416                 goto restart;
1417
1418         case T_IDENTIFIER:
1419                 if(is_typedef_symbol(token.v.symbol)) {
1420                         type = parse_typename();
1421                 } else {
1422                         expression = parse_expression();
1423                         type       = expression->base.type;
1424                 }
1425                 break;
1426
1427         TYPENAME_START
1428                 type = parse_typename();
1429                 break;
1430
1431         default:
1432                 expression = parse_expression();
1433                 type       = expression->base.type;
1434                 break;
1435         }
1436
1437         expect(')');
1438
1439         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
1440         typeof_type->typeoft.expression  = expression;
1441         typeof_type->typeoft.typeof_type = type;
1442
1443         return typeof_type;
1444 }
1445
1446 typedef enum {
1447         SPECIFIER_SIGNED    = 1 << 0,
1448         SPECIFIER_UNSIGNED  = 1 << 1,
1449         SPECIFIER_LONG      = 1 << 2,
1450         SPECIFIER_INT       = 1 << 3,
1451         SPECIFIER_DOUBLE    = 1 << 4,
1452         SPECIFIER_CHAR      = 1 << 5,
1453         SPECIFIER_SHORT     = 1 << 6,
1454         SPECIFIER_LONG_LONG = 1 << 7,
1455         SPECIFIER_FLOAT     = 1 << 8,
1456         SPECIFIER_BOOL      = 1 << 9,
1457         SPECIFIER_VOID      = 1 << 10,
1458 #ifdef PROVIDE_COMPLEX
1459         SPECIFIER_COMPLEX   = 1 << 11,
1460         SPECIFIER_IMAGINARY = 1 << 12,
1461 #endif
1462 } specifiers_t;
1463
1464 static type_t *create_builtin_type(symbol_t *const symbol,
1465                                    type_t *const real_type)
1466 {
1467         type_t *type            = allocate_type_zero(TYPE_BUILTIN);
1468         type->builtin.symbol    = symbol;
1469         type->builtin.real_type = real_type;
1470
1471         type_t *result = typehash_insert(type);
1472         if (type != result) {
1473                 free_type(type);
1474         }
1475
1476         return result;
1477 }
1478
1479 static type_t *get_typedef_type(symbol_t *symbol)
1480 {
1481         declaration_t *declaration = get_declaration(symbol, NAMESPACE_NORMAL);
1482         if(declaration == NULL
1483                         || declaration->storage_class != STORAGE_CLASS_TYPEDEF)
1484                 return NULL;
1485
1486         type_t *type               = allocate_type_zero(TYPE_TYPEDEF);
1487         type->typedeft.declaration = declaration;
1488
1489         return type;
1490 }
1491
1492 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
1493 {
1494         type_t   *type            = NULL;
1495         unsigned  type_qualifiers = 0;
1496         unsigned  type_specifiers = 0;
1497         int       newtype         = 0;
1498
1499         specifiers->source_position = token.source_position;
1500
1501         while(true) {
1502                 switch(token.type) {
1503
1504                 /* storage class */
1505 #define MATCH_STORAGE_CLASS(token, class)                                \
1506                 case token:                                                      \
1507                         if(specifiers->storage_class != STORAGE_CLASS_NONE) {        \
1508                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
1509                         }                                                            \
1510                         specifiers->storage_class = class;                           \
1511                         next_token();                                                \
1512                         break;
1513
1514                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
1515                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
1516                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
1517                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
1518                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
1519
1520                 case T___thread:
1521                         switch (specifiers->storage_class) {
1522                                 case STORAGE_CLASS_NONE:
1523                                         specifiers->storage_class = STORAGE_CLASS_THREAD;
1524                                         break;
1525
1526                                 case STORAGE_CLASS_EXTERN:
1527                                         specifiers->storage_class = STORAGE_CLASS_THREAD_EXTERN;
1528                                         break;
1529
1530                                 case STORAGE_CLASS_STATIC:
1531                                         specifiers->storage_class = STORAGE_CLASS_THREAD_STATIC;
1532                                         break;
1533
1534                                 default:
1535                                         errorf(HERE, "multiple storage classes in declaration specifiers");
1536                                         break;
1537                         }
1538                         next_token();
1539                         break;
1540
1541                 /* type qualifiers */
1542 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
1543                 case token:                                                     \
1544                         type_qualifiers |= qualifier;                               \
1545                         next_token();                                               \
1546                         break;
1547
1548                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1549                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1550                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1551
1552                 case T___extension__:
1553                         /* TODO */
1554                         next_token();
1555                         break;
1556
1557                 /* type specifiers */
1558 #define MATCH_SPECIFIER(token, specifier, name)                         \
1559                 case token:                                                     \
1560                         next_token();                                               \
1561                         if(type_specifiers & specifier) {                           \
1562                                 errorf(HERE, "multiple " name " type specifiers given"); \
1563                         } else {                                                    \
1564                                 type_specifiers |= specifier;                           \
1565                         }                                                           \
1566                         break;
1567
1568                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void")
1569                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char")
1570                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short")
1571                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int")
1572                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float")
1573                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double")
1574                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed")
1575                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned")
1576                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool")
1577 #ifdef PROVIDE_COMPLEX
1578                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex")
1579                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary")
1580 #endif
1581                 case T_forceinline:
1582                         /* only in microsoft mode */
1583                         specifiers->decl_modifiers |= DM_FORCEINLINE;
1584
1585                 case T_inline:
1586                         next_token();
1587                         specifiers->is_inline = true;
1588                         break;
1589
1590                 case T_long:
1591                         next_token();
1592                         if(type_specifiers & SPECIFIER_LONG_LONG) {
1593                                 errorf(HERE, "multiple type specifiers given");
1594                         } else if(type_specifiers & SPECIFIER_LONG) {
1595                                 type_specifiers |= SPECIFIER_LONG_LONG;
1596                         } else {
1597                                 type_specifiers |= SPECIFIER_LONG;
1598                         }
1599                         break;
1600
1601                 /* TODO: if is_type_valid(type) for the following rules should issue
1602                  * an error */
1603                 case T_struct: {
1604                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
1605
1606                         type->compound.declaration = parse_compound_type_specifier(true);
1607                         break;
1608                 }
1609                 case T_union: {
1610                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
1611
1612                         type->compound.declaration = parse_compound_type_specifier(false);
1613                         break;
1614                 }
1615                 case T_enum:
1616                         type = parse_enum_specifier();
1617                         break;
1618                 case T___typeof__:
1619                         type = parse_typeof();
1620                         break;
1621                 case T___builtin_va_list:
1622                         type = duplicate_type(type_valist);
1623                         next_token();
1624                         break;
1625
1626                 case T___attribute__:
1627                         /* TODO */
1628                         parse_attributes();
1629                         break;
1630
1631                 case T_IDENTIFIER: {
1632                         type_t *typedef_type = get_typedef_type(token.v.symbol);
1633
1634                         if(typedef_type == NULL)
1635                                 goto finish_specifiers;
1636
1637                         next_token();
1638                         type = typedef_type;
1639                         break;
1640                 }
1641
1642                 /* function specifier */
1643                 default:
1644                         goto finish_specifiers;
1645                 }
1646         }
1647
1648 finish_specifiers:
1649
1650         if(type == NULL) {
1651                 atomic_type_kind_t atomic_type;
1652
1653                 /* match valid basic types */
1654                 switch(type_specifiers) {
1655                 case SPECIFIER_VOID:
1656                         atomic_type = ATOMIC_TYPE_VOID;
1657                         break;
1658                 case SPECIFIER_CHAR:
1659                         atomic_type = ATOMIC_TYPE_CHAR;
1660                         break;
1661                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
1662                         atomic_type = ATOMIC_TYPE_SCHAR;
1663                         break;
1664                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
1665                         atomic_type = ATOMIC_TYPE_UCHAR;
1666                         break;
1667                 case SPECIFIER_SHORT:
1668                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
1669                 case SPECIFIER_SHORT | SPECIFIER_INT:
1670                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1671                         atomic_type = ATOMIC_TYPE_SHORT;
1672                         break;
1673                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
1674                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
1675                         atomic_type = ATOMIC_TYPE_USHORT;
1676                         break;
1677                 case SPECIFIER_INT:
1678                 case SPECIFIER_SIGNED:
1679                 case SPECIFIER_SIGNED | SPECIFIER_INT:
1680                         atomic_type = ATOMIC_TYPE_INT;
1681                         break;
1682                 case SPECIFIER_UNSIGNED:
1683                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
1684                         atomic_type = ATOMIC_TYPE_UINT;
1685                         break;
1686                 case SPECIFIER_LONG:
1687                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
1688                 case SPECIFIER_LONG | SPECIFIER_INT:
1689                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1690                         atomic_type = ATOMIC_TYPE_LONG;
1691                         break;
1692                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
1693                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
1694                         atomic_type = ATOMIC_TYPE_ULONG;
1695                         break;
1696                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1697                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1698                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
1699                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1700                         | SPECIFIER_INT:
1701                         atomic_type = ATOMIC_TYPE_LONGLONG;
1702                         break;
1703                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
1704                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
1705                         | SPECIFIER_INT:
1706                         atomic_type = ATOMIC_TYPE_ULONGLONG;
1707                         break;
1708                 case SPECIFIER_FLOAT:
1709                         atomic_type = ATOMIC_TYPE_FLOAT;
1710                         break;
1711                 case SPECIFIER_DOUBLE:
1712                         atomic_type = ATOMIC_TYPE_DOUBLE;
1713                         break;
1714                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
1715                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
1716                         break;
1717                 case SPECIFIER_BOOL:
1718                         atomic_type = ATOMIC_TYPE_BOOL;
1719                         break;
1720 #ifdef PROVIDE_COMPLEX
1721                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
1722                         atomic_type = ATOMIC_TYPE_FLOAT_COMPLEX;
1723                         break;
1724                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1725                         atomic_type = ATOMIC_TYPE_DOUBLE_COMPLEX;
1726                         break;
1727                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
1728                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_COMPLEX;
1729                         break;
1730                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
1731                         atomic_type = ATOMIC_TYPE_FLOAT_IMAGINARY;
1732                         break;
1733                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1734                         atomic_type = ATOMIC_TYPE_DOUBLE_IMAGINARY;
1735                         break;
1736                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
1737                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE_IMAGINARY;
1738                         break;
1739 #endif
1740                 default:
1741                         /* invalid specifier combination, give an error message */
1742                         if(type_specifiers == 0) {
1743                                 if (! strict_mode) {
1744                                         if (warning.implicit_int) {
1745                                                 warningf(HERE, "no type specifiers in declaration, using 'int'");
1746                                         }
1747                                         atomic_type = ATOMIC_TYPE_INT;
1748                                         break;
1749                                 } else {
1750                                         errorf(HERE, "no type specifiers given in declaration");
1751                                 }
1752                         } else if((type_specifiers & SPECIFIER_SIGNED) &&
1753                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
1754                                 errorf(HERE, "signed and unsigned specifiers gives");
1755                         } else if(type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
1756                                 errorf(HERE, "only integer types can be signed or unsigned");
1757                         } else {
1758                                 errorf(HERE, "multiple datatypes in declaration");
1759                         }
1760                         atomic_type = ATOMIC_TYPE_INVALID;
1761                 }
1762
1763                 type               = allocate_type_zero(TYPE_ATOMIC);
1764                 type->atomic.akind = atomic_type;
1765                 newtype            = 1;
1766         } else {
1767                 if(type_specifiers != 0) {
1768                         errorf(HERE, "multiple datatypes in declaration");
1769                 }
1770         }
1771
1772         type->base.qualifiers = type_qualifiers;
1773
1774         type_t *result = typehash_insert(type);
1775         if(newtype && result != type) {
1776                 free_type(type);
1777         }
1778
1779         specifiers->type = result;
1780 }
1781
1782 static type_qualifiers_t parse_type_qualifiers(void)
1783 {
1784         type_qualifiers_t type_qualifiers = TYPE_QUALIFIER_NONE;
1785
1786         while(true) {
1787                 switch(token.type) {
1788                 /* type qualifiers */
1789                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
1790                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
1791                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
1792
1793                 default:
1794                         return type_qualifiers;
1795                 }
1796         }
1797 }
1798
1799 static declaration_t *parse_identifier_list(void)
1800 {
1801         declaration_t *declarations     = NULL;
1802         declaration_t *last_declaration = NULL;
1803         do {
1804                 declaration_t *const declaration = allocate_declaration_zero();
1805                 declaration->type            = NULL; /* a K&R parameter list has no types, yet */
1806                 declaration->source_position = token.source_position;
1807                 declaration->symbol          = token.v.symbol;
1808                 next_token();
1809
1810                 if(last_declaration != NULL) {
1811                         last_declaration->next = declaration;
1812                 } else {
1813                         declarations = declaration;
1814                 }
1815                 last_declaration = declaration;
1816
1817                 if(token.type != ',')
1818                         break;
1819                 next_token();
1820         } while(token.type == T_IDENTIFIER);
1821
1822         return declarations;
1823 }
1824
1825 static void semantic_parameter(declaration_t *declaration)
1826 {
1827         /* TODO: improve error messages */
1828
1829         if(declaration->storage_class == STORAGE_CLASS_TYPEDEF) {
1830                 errorf(HERE, "typedef not allowed in parameter list");
1831         } else if(declaration->storage_class != STORAGE_CLASS_NONE
1832                         && declaration->storage_class != STORAGE_CLASS_REGISTER) {
1833                 errorf(HERE, "parameter may only have none or register storage class");
1834         }
1835
1836         type_t *const orig_type = declaration->type;
1837         type_t *      type      = skip_typeref(orig_type);
1838
1839         /* Array as last part of a parameter type is just syntactic sugar.  Turn it
1840          * into a pointer. § 6.7.5.3 (7) */
1841         if (is_type_array(type)) {
1842                 type_t *const element_type = type->array.element_type;
1843
1844                 type = make_pointer_type(element_type, type->base.qualifiers);
1845
1846                 declaration->type = type;
1847         }
1848
1849         if(is_type_incomplete(type)) {
1850                 errorf(HERE, "incomplete type ('%T') not allowed for parameter '%Y'",
1851                        orig_type, declaration->symbol);
1852         }
1853 }
1854
1855 static declaration_t *parse_parameter(void)
1856 {
1857         declaration_specifiers_t specifiers;
1858         memset(&specifiers, 0, sizeof(specifiers));
1859
1860         parse_declaration_specifiers(&specifiers);
1861
1862         declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/true);
1863
1864         semantic_parameter(declaration);
1865
1866         return declaration;
1867 }
1868
1869 static declaration_t *parse_parameters(function_type_t *type)
1870 {
1871         if(token.type == T_IDENTIFIER) {
1872                 symbol_t *symbol = token.v.symbol;
1873                 if(!is_typedef_symbol(symbol)) {
1874                         type->kr_style_parameters = true;
1875                         return parse_identifier_list();
1876                 }
1877         }
1878
1879         if(token.type == ')') {
1880                 type->unspecified_parameters = 1;
1881                 return NULL;
1882         }
1883         if(token.type == T_void && look_ahead(1)->type == ')') {
1884                 next_token();
1885                 return NULL;
1886         }
1887
1888         declaration_t        *declarations = NULL;
1889         declaration_t        *declaration;
1890         declaration_t        *last_declaration = NULL;
1891         function_parameter_t *parameter;
1892         function_parameter_t *last_parameter = NULL;
1893
1894         while(true) {
1895                 switch(token.type) {
1896                 case T_DOTDOTDOT:
1897                         next_token();
1898                         type->variadic = 1;
1899                         return declarations;
1900
1901                 case T_IDENTIFIER:
1902                 case T___extension__:
1903                 DECLARATION_START
1904                         declaration = parse_parameter();
1905
1906                         parameter       = obstack_alloc(type_obst, sizeof(parameter[0]));
1907                         memset(parameter, 0, sizeof(parameter[0]));
1908                         parameter->type = declaration->type;
1909
1910                         if(last_parameter != NULL) {
1911                                 last_declaration->next = declaration;
1912                                 last_parameter->next   = parameter;
1913                         } else {
1914                                 type->parameters = parameter;
1915                                 declarations     = declaration;
1916                         }
1917                         last_parameter   = parameter;
1918                         last_declaration = declaration;
1919                         break;
1920
1921                 default:
1922                         return declarations;
1923                 }
1924                 if(token.type != ',')
1925                         return declarations;
1926                 next_token();
1927         }
1928 }
1929
1930 typedef enum {
1931         CONSTRUCT_INVALID,
1932         CONSTRUCT_POINTER,
1933         CONSTRUCT_FUNCTION,
1934         CONSTRUCT_ARRAY
1935 } construct_type_type_t;
1936
1937 typedef struct construct_type_t construct_type_t;
1938 struct construct_type_t {
1939         construct_type_type_t  type;
1940         construct_type_t      *next;
1941 };
1942
1943 typedef struct parsed_pointer_t parsed_pointer_t;
1944 struct parsed_pointer_t {
1945         construct_type_t  construct_type;
1946         type_qualifiers_t type_qualifiers;
1947 };
1948
1949 typedef struct construct_function_type_t construct_function_type_t;
1950 struct construct_function_type_t {
1951         construct_type_t  construct_type;
1952         type_t           *function_type;
1953 };
1954
1955 typedef struct parsed_array_t parsed_array_t;
1956 struct parsed_array_t {
1957         construct_type_t  construct_type;
1958         type_qualifiers_t type_qualifiers;
1959         bool              is_static;
1960         bool              is_variable;
1961         expression_t     *size;
1962 };
1963
1964 typedef struct construct_base_type_t construct_base_type_t;
1965 struct construct_base_type_t {
1966         construct_type_t  construct_type;
1967         type_t           *type;
1968 };
1969
1970 static construct_type_t *parse_pointer_declarator(void)
1971 {
1972         eat('*');
1973
1974         parsed_pointer_t *pointer = obstack_alloc(&temp_obst, sizeof(pointer[0]));
1975         memset(pointer, 0, sizeof(pointer[0]));
1976         pointer->construct_type.type = CONSTRUCT_POINTER;
1977         pointer->type_qualifiers     = parse_type_qualifiers();
1978
1979         return (construct_type_t*) pointer;
1980 }
1981
1982 static construct_type_t *parse_array_declarator(void)
1983 {
1984         eat('[');
1985
1986         parsed_array_t *array = obstack_alloc(&temp_obst, sizeof(array[0]));
1987         memset(array, 0, sizeof(array[0]));
1988         array->construct_type.type = CONSTRUCT_ARRAY;
1989
1990         if(token.type == T_static) {
1991                 array->is_static = true;
1992                 next_token();
1993         }
1994
1995         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
1996         if(type_qualifiers != 0) {
1997                 if(token.type == T_static) {
1998                         array->is_static = true;
1999                         next_token();
2000                 }
2001         }
2002         array->type_qualifiers = type_qualifiers;
2003
2004         if(token.type == '*' && look_ahead(1)->type == ']') {
2005                 array->is_variable = true;
2006                 next_token();
2007         } else if(token.type != ']') {
2008                 array->size = parse_assignment_expression();
2009         }
2010
2011         expect(']');
2012
2013         return (construct_type_t*) array;
2014 }
2015
2016 static construct_type_t *parse_function_declarator(declaration_t *declaration)
2017 {
2018         eat('(');
2019
2020         type_t *type = allocate_type_zero(TYPE_FUNCTION);
2021
2022         declaration_t *parameters = parse_parameters(&type->function);
2023         if(declaration != NULL) {
2024                 declaration->scope.declarations = parameters;
2025         }
2026
2027         construct_function_type_t *construct_function_type =
2028                 obstack_alloc(&temp_obst, sizeof(construct_function_type[0]));
2029         memset(construct_function_type, 0, sizeof(construct_function_type[0]));
2030         construct_function_type->construct_type.type = CONSTRUCT_FUNCTION;
2031         construct_function_type->function_type       = type;
2032
2033         expect(')');
2034
2035         return (construct_type_t*) construct_function_type;
2036 }
2037
2038 static construct_type_t *parse_inner_declarator(declaration_t *declaration,
2039                 bool may_be_abstract)
2040 {
2041         /* construct a single linked list of construct_type_t's which describe
2042          * how to construct the final declarator type */
2043         construct_type_t *first = NULL;
2044         construct_type_t *last  = NULL;
2045
2046         /* pointers */
2047         while(token.type == '*') {
2048                 construct_type_t *type = parse_pointer_declarator();
2049
2050                 if(last == NULL) {
2051                         first = type;
2052                         last  = type;
2053                 } else {
2054                         last->next = type;
2055                         last       = type;
2056                 }
2057         }
2058
2059         /* TODO: find out if this is correct */
2060         parse_attributes();
2061
2062         construct_type_t *inner_types = NULL;
2063
2064         switch(token.type) {
2065         case T_IDENTIFIER:
2066                 if(declaration == NULL) {
2067                         errorf(HERE, "no identifier expected in typename");
2068                 } else {
2069                         declaration->symbol          = token.v.symbol;
2070                         declaration->source_position = token.source_position;
2071                 }
2072                 next_token();
2073                 break;
2074         case '(':
2075                 next_token();
2076                 inner_types = parse_inner_declarator(declaration, may_be_abstract);
2077                 expect(')');
2078                 break;
2079         default:
2080                 if(may_be_abstract)
2081                         break;
2082                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', 0);
2083                 /* avoid a loop in the outermost scope, because eat_statement doesn't
2084                  * eat '}' */
2085                 if(token.type == '}' && current_function == NULL) {
2086                         next_token();
2087                 } else {
2088                         eat_statement();
2089                 }
2090                 return NULL;
2091         }
2092
2093         construct_type_t *p = last;
2094
2095         while(true) {
2096                 construct_type_t *type;
2097                 switch(token.type) {
2098                 case '(':
2099                         type = parse_function_declarator(declaration);
2100                         break;
2101                 case '[':
2102                         type = parse_array_declarator();
2103                         break;
2104                 default:
2105                         goto declarator_finished;
2106                 }
2107
2108                 /* insert in the middle of the list (behind p) */
2109                 if(p != NULL) {
2110                         type->next = p->next;
2111                         p->next    = type;
2112                 } else {
2113                         type->next = first;
2114                         first      = type;
2115                 }
2116                 if(last == p) {
2117                         last = type;
2118                 }
2119         }
2120
2121 declarator_finished:
2122         parse_attributes();
2123
2124         /* append inner_types at the end of the list, we don't to set last anymore
2125          * as it's not needed anymore */
2126         if(last == NULL) {
2127                 assert(first == NULL);
2128                 first = inner_types;
2129         } else {
2130                 last->next = inner_types;
2131         }
2132
2133         return first;
2134 }
2135
2136 static type_t *construct_declarator_type(construct_type_t *construct_list,
2137                                          type_t *type)
2138 {
2139         construct_type_t *iter = construct_list;
2140         for( ; iter != NULL; iter = iter->next) {
2141                 switch(iter->type) {
2142                 case CONSTRUCT_INVALID:
2143                         panic("invalid type construction found");
2144                 case CONSTRUCT_FUNCTION: {
2145                         construct_function_type_t *construct_function_type
2146                                 = (construct_function_type_t*) iter;
2147
2148                         type_t *function_type = construct_function_type->function_type;
2149
2150                         function_type->function.return_type = type;
2151
2152                         type_t *skipped_return_type = skip_typeref(type);
2153                         if (is_type_function(skipped_return_type)) {
2154                                 errorf(HERE, "function returning function is not allowed");
2155                                 type = type_error_type;
2156                         } else if (is_type_array(skipped_return_type)) {
2157                                 errorf(HERE, "function returning array is not allowed");
2158                                 type = type_error_type;
2159                         } else {
2160                                 type = function_type;
2161                         }
2162                         break;
2163                 }
2164
2165                 case CONSTRUCT_POINTER: {
2166                         parsed_pointer_t *parsed_pointer = (parsed_pointer_t*) iter;
2167                         type_t           *pointer_type   = allocate_type_zero(TYPE_POINTER);
2168                         pointer_type->pointer.points_to  = type;
2169                         pointer_type->base.qualifiers    = parsed_pointer->type_qualifiers;
2170
2171                         type = pointer_type;
2172                         break;
2173                 }
2174
2175                 case CONSTRUCT_ARRAY: {
2176                         parsed_array_t *parsed_array  = (parsed_array_t*) iter;
2177                         type_t         *array_type    = allocate_type_zero(TYPE_ARRAY);
2178
2179                         array_type->base.qualifiers    = parsed_array->type_qualifiers;
2180                         array_type->array.element_type = type;
2181                         array_type->array.is_static    = parsed_array->is_static;
2182                         array_type->array.is_variable  = parsed_array->is_variable;
2183                         array_type->array.size         = parsed_array->size;
2184
2185                         type_t *skipped_type = skip_typeref(type);
2186                         if (is_type_atomic(skipped_type, ATOMIC_TYPE_VOID)) {
2187                                 errorf(HERE, "array of void is not allowed");
2188                                 type = type_error_type;
2189                         } else {
2190                                 type = array_type;
2191                         }
2192                         break;
2193                 }
2194                 }
2195
2196                 type_t *hashed_type = typehash_insert(type);
2197                 if(hashed_type != type) {
2198                         /* the function type was constructed earlier freeing it here will
2199                          * destroy other types... */
2200                         if(iter->type != CONSTRUCT_FUNCTION) {
2201                                 free_type(type);
2202                         }
2203                         type = hashed_type;
2204                 }
2205         }
2206
2207         return type;
2208 }
2209
2210 static declaration_t *parse_declarator(
2211                 const declaration_specifiers_t *specifiers, bool may_be_abstract)
2212 {
2213         declaration_t *const declaration = allocate_declaration_zero();
2214         declaration->storage_class  = specifiers->storage_class;
2215         declaration->modifiers      = specifiers->decl_modifiers;
2216         declaration->is_inline      = specifiers->is_inline;
2217
2218         construct_type_t *construct_type
2219                 = parse_inner_declarator(declaration, may_be_abstract);
2220         type_t *const type = specifiers->type;
2221         declaration->type = construct_declarator_type(construct_type, type);
2222
2223         if(construct_type != NULL) {
2224                 obstack_free(&temp_obst, construct_type);
2225         }
2226
2227         return declaration;
2228 }
2229
2230 static type_t *parse_abstract_declarator(type_t *base_type)
2231 {
2232         construct_type_t *construct_type = parse_inner_declarator(NULL, 1);
2233
2234         type_t *result = construct_declarator_type(construct_type, base_type);
2235         if(construct_type != NULL) {
2236                 obstack_free(&temp_obst, construct_type);
2237         }
2238
2239         return result;
2240 }
2241
2242 static declaration_t *append_declaration(declaration_t* const declaration)
2243 {
2244         if (last_declaration != NULL) {
2245                 last_declaration->next = declaration;
2246         } else {
2247                 scope->declarations = declaration;
2248         }
2249         last_declaration = declaration;
2250         return declaration;
2251 }
2252
2253 /**
2254  * Check if the declaration of main is suspicious.  main should be a
2255  * function with external linkage, returning int, taking either zero
2256  * arguments, two, or three arguments of appropriate types, ie.
2257  *
2258  * int main([ int argc, char **argv [, char **env ] ]).
2259  *
2260  * @param decl    the declaration to check
2261  * @param type    the function type of the declaration
2262  */
2263 static void check_type_of_main(const declaration_t *const decl, const function_type_t *const func_type)
2264 {
2265         if (decl->storage_class == STORAGE_CLASS_STATIC) {
2266                 warningf(decl->source_position, "'main' is normally a non-static function");
2267         }
2268         if (skip_typeref(func_type->return_type) != type_int) {
2269                 warningf(decl->source_position, "return type of 'main' should be 'int', but is '%T'", func_type->return_type);
2270         }
2271         const function_parameter_t *parm = func_type->parameters;
2272         if (parm != NULL) {
2273                 type_t *const first_type = parm->type;
2274                 if (!types_compatible(skip_typeref(first_type), type_int)) {
2275                         warningf(decl->source_position, "first argument of 'main' should be 'int', but is '%T'", first_type);
2276                 }
2277                 parm = parm->next;
2278                 if (parm != NULL) {
2279                         type_t *const second_type = parm->type;
2280                         if (!types_compatible(skip_typeref(second_type), type_char_ptr_ptr)) {
2281                                 warningf(decl->source_position, "second argument of 'main' should be 'char**', but is '%T'", second_type);
2282                         }
2283                         parm = parm->next;
2284                         if (parm != NULL) {
2285                                 type_t *const third_type = parm->type;
2286                                 if (!types_compatible(skip_typeref(third_type), type_char_ptr_ptr)) {
2287                                         warningf(decl->source_position, "third argument of 'main' should be 'char**', but is '%T'", third_type);
2288                                 }
2289                                 parm = parm->next;
2290                                 if (parm != NULL) {
2291                                         warningf(decl->source_position, "'main' takes only zero, two or three arguments");
2292                                 }
2293                         }
2294                 } else {
2295                         warningf(decl->source_position, "'main' takes only zero, two or three arguments");
2296                 }
2297         }
2298 }
2299
2300 /**
2301  * Check if a symbol is the equal to "main".
2302  */
2303 static bool is_sym_main(const symbol_t *const sym)
2304 {
2305         return strcmp(sym->string, "main") == 0;
2306 }
2307
2308 static declaration_t *internal_record_declaration(
2309         declaration_t *const declaration,
2310         const bool is_function_definition)
2311 {
2312         const symbol_t *const symbol  = declaration->symbol;
2313         const namespace_t     namespc = (namespace_t)declaration->namespc;
2314
2315         type_t *const orig_type = declaration->type;
2316         type_t *const type      = skip_typeref(orig_type);
2317         if (is_type_function(type) &&
2318                         type->function.unspecified_parameters &&
2319                         warning.strict_prototypes) {
2320                 warningf(declaration->source_position,
2321                          "function declaration '%#T' is not a prototype",
2322                          orig_type, declaration->symbol);
2323         }
2324
2325         if (is_function_definition && warning.main && is_sym_main(symbol)) {
2326                 check_type_of_main(declaration, &type->function);
2327         }
2328
2329         assert(declaration->symbol != NULL);
2330         declaration_t *previous_declaration = get_declaration(symbol, namespc);
2331
2332         assert(declaration != previous_declaration);
2333         if (previous_declaration != NULL) {
2334                 if (previous_declaration->parent_scope == scope) {
2335                         /* can happen for K&R style declarations */
2336                         if(previous_declaration->type == NULL) {
2337                                 previous_declaration->type = declaration->type;
2338                         }
2339
2340                         const type_t *prev_type = skip_typeref(previous_declaration->type);
2341                         if (!types_compatible(type, prev_type)) {
2342                                 errorf(declaration->source_position,
2343                                        "declaration '%#T' is incompatible with "
2344                                        "previous declaration '%#T'",
2345                                        orig_type, symbol, previous_declaration->type, symbol);
2346                                 errorf(previous_declaration->source_position,
2347                                        "previous declaration of '%Y' was here", symbol);
2348                         } else {
2349                                 unsigned old_storage_class
2350                                         = previous_declaration->storage_class;
2351                                 unsigned new_storage_class = declaration->storage_class;
2352
2353                                 if(is_type_incomplete(prev_type)) {
2354                                         previous_declaration->type = type;
2355                                         prev_type                  = type;
2356                                 }
2357
2358                                 /* pretend no storage class means extern for function
2359                                  * declarations (except if the previous declaration is neither
2360                                  * none nor extern) */
2361                                 if (is_type_function(type)) {
2362                                         switch (old_storage_class) {
2363                                                 case STORAGE_CLASS_NONE:
2364                                                         old_storage_class = STORAGE_CLASS_EXTERN;
2365
2366                                                 case STORAGE_CLASS_EXTERN:
2367                                                         if (is_function_definition) {
2368                                                                 if (warning.missing_prototypes &&
2369                                                                     prev_type->function.unspecified_parameters &&
2370                                                                     !is_sym_main(symbol)) {
2371                                                                         warningf(declaration->source_position,
2372                                                                                  "no previous prototype for '%#T'",
2373                                                                                  orig_type, symbol);
2374                                                                 }
2375                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
2376                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
2377                                                         }
2378                                                         break;
2379
2380                                                 default: break;
2381                                         }
2382                                 }
2383
2384                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
2385                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
2386 warn_redundant_declaration:
2387                                         if (warning.redundant_decls) {
2388                                                 warningf(declaration->source_position,
2389                                                          "redundant declaration for '%Y'", symbol);
2390                                                 warningf(previous_declaration->source_position,
2391                                                          "previous declaration of '%Y' was here",
2392                                                          symbol);
2393                                         }
2394                                 } else if (current_function == NULL) {
2395                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
2396                                                         new_storage_class == STORAGE_CLASS_STATIC) {
2397                                                 errorf(declaration->source_position,
2398                                                        "static declaration of '%Y' follows non-static declaration",
2399                                                        symbol);
2400                                                 errorf(previous_declaration->source_position,
2401                                                        "previous declaration of '%Y' was here", symbol);
2402                                         } else {
2403                                                 if (old_storage_class != STORAGE_CLASS_EXTERN && !is_function_definition) {
2404                                                         goto warn_redundant_declaration;
2405                                                 }
2406                                                 if (new_storage_class == STORAGE_CLASS_NONE) {
2407                                                         previous_declaration->storage_class = STORAGE_CLASS_NONE;
2408                                                 }
2409                                         }
2410                                 } else {
2411                                         if (old_storage_class == new_storage_class) {
2412                                                 errorf(declaration->source_position,
2413                                                        "redeclaration of '%Y'", symbol);
2414                                         } else {
2415                                                 errorf(declaration->source_position,
2416                                                        "redeclaration of '%Y' with different linkage",
2417                                                        symbol);
2418                                         }
2419                                         errorf(previous_declaration->source_position,
2420                                                "previous declaration of '%Y' was here", symbol);
2421                                 }
2422                         }
2423                         return previous_declaration;
2424                 }
2425         } else if (is_function_definition) {
2426                 if (declaration->storage_class != STORAGE_CLASS_STATIC) {
2427                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
2428                                 warningf(declaration->source_position,
2429                                          "no previous prototype for '%#T'", orig_type, symbol);
2430                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
2431                                 warningf(declaration->source_position,
2432                                          "no previous declaration for '%#T'", orig_type,
2433                                          symbol);
2434                         }
2435                 }
2436         } else if (warning.missing_declarations &&
2437             scope == global_scope &&
2438             !is_type_function(type) && (
2439               declaration->storage_class == STORAGE_CLASS_NONE ||
2440               declaration->storage_class == STORAGE_CLASS_THREAD
2441             )) {
2442                 warningf(declaration->source_position,
2443                          "no previous declaration for '%#T'", orig_type, symbol);
2444         }
2445
2446         assert(declaration->parent_scope == NULL);
2447         assert(scope != NULL);
2448
2449         declaration->parent_scope = scope;
2450
2451         environment_push(declaration);
2452         return append_declaration(declaration);
2453 }
2454
2455 static declaration_t *record_declaration(declaration_t *declaration)
2456 {
2457         return internal_record_declaration(declaration, false);
2458 }
2459
2460 static declaration_t *record_function_definition(declaration_t *declaration)
2461 {
2462         return internal_record_declaration(declaration, true);
2463 }
2464
2465 static void parser_error_multiple_definition(declaration_t *declaration,
2466                 const source_position_t source_position)
2467 {
2468         errorf(source_position, "multiple definition of symbol '%Y'",
2469                declaration->symbol);
2470         errorf(declaration->source_position,
2471                "this is the location of the previous definition.");
2472 }
2473
2474 static bool is_declaration_specifier(const token_t *token,
2475                                      bool only_type_specifiers)
2476 {
2477         switch(token->type) {
2478                 TYPE_SPECIFIERS
2479                         return true;
2480                 case T_IDENTIFIER:
2481                         return is_typedef_symbol(token->v.symbol);
2482
2483                 case T___extension__:
2484                 STORAGE_CLASSES
2485                 TYPE_QUALIFIERS
2486                         return !only_type_specifiers;
2487
2488                 default:
2489                         return false;
2490         }
2491 }
2492
2493 static void parse_init_declarator_rest(declaration_t *declaration)
2494 {
2495         eat('=');
2496
2497         type_t *orig_type = declaration->type;
2498         type_t *type      = type = skip_typeref(orig_type);
2499
2500         if(declaration->init.initializer != NULL) {
2501                 parser_error_multiple_definition(declaration, token.source_position);
2502         }
2503
2504         initializer_t *initializer = parse_initializer(type);
2505
2506         /* § 6.7.5 (22)  array initializers for arrays with unknown size determine
2507          * the array type size */
2508         if(is_type_array(type) && initializer != NULL) {
2509                 array_type_t *array_type = &type->array;
2510
2511                 if(array_type->size == NULL) {
2512                         expression_t *cnst = allocate_expression_zero(EXPR_CONST);
2513
2514                         cnst->base.type = type_size_t;
2515
2516                         switch (initializer->kind) {
2517                                 case INITIALIZER_LIST: {
2518                                         cnst->conste.v.int_value = initializer->list.len;
2519                                         break;
2520                                 }
2521
2522                                 case INITIALIZER_STRING: {
2523                                         cnst->conste.v.int_value = initializer->string.string.size;
2524                                         break;
2525                                 }
2526
2527                                 case INITIALIZER_WIDE_STRING: {
2528                                         cnst->conste.v.int_value = initializer->wide_string.string.size;
2529                                         break;
2530                                 }
2531
2532                                 default:
2533                                         panic("invalid initializer type");
2534                         }
2535
2536                         array_type->size = cnst;
2537                 }
2538         }
2539
2540         if(is_type_function(type)) {
2541                 errorf(declaration->source_position,
2542                        "initializers not allowed for function types at declator '%Y' (type '%T')",
2543                        declaration->symbol, orig_type);
2544         } else {
2545                 declaration->init.initializer = initializer;
2546         }
2547 }
2548
2549 /* parse rest of a declaration without any declarator */
2550 static void parse_anonymous_declaration_rest(
2551                 const declaration_specifiers_t *specifiers,
2552                 parsed_declaration_func finished_declaration)
2553 {
2554         eat(';');
2555
2556         declaration_t *const declaration = allocate_declaration_zero();
2557         declaration->type            = specifiers->type;
2558         declaration->storage_class   = specifiers->storage_class;
2559         declaration->source_position = specifiers->source_position;
2560
2561         if (declaration->storage_class != STORAGE_CLASS_NONE) {
2562                 warningf(declaration->source_position, "useless storage class in empty declaration");
2563         }
2564
2565         type_t *type = declaration->type;
2566         switch (type->kind) {
2567                 case TYPE_COMPOUND_STRUCT:
2568                 case TYPE_COMPOUND_UNION: {
2569                         if (type->compound.declaration->symbol == NULL) {
2570                                 warningf(declaration->source_position, "unnamed struct/union that defines no instances");
2571                         }
2572                         break;
2573                 }
2574
2575                 case TYPE_ENUM:
2576                         break;
2577
2578                 default:
2579                         warningf(declaration->source_position, "empty declaration");
2580                         break;
2581         }
2582
2583         finished_declaration(declaration);
2584 }
2585
2586 static void parse_declaration_rest(declaration_t *ndeclaration,
2587                 const declaration_specifiers_t *specifiers,
2588                 parsed_declaration_func finished_declaration)
2589 {
2590         while(true) {
2591                 declaration_t *declaration = finished_declaration(ndeclaration);
2592
2593                 type_t *orig_type = declaration->type;
2594                 type_t *type      = skip_typeref(orig_type);
2595
2596                 if (type->kind != TYPE_FUNCTION &&
2597                     declaration->is_inline &&
2598                     is_type_valid(type)) {
2599                         warningf(declaration->source_position,
2600                                  "variable '%Y' declared 'inline'\n", declaration->symbol);
2601                 }
2602
2603                 if(token.type == '=') {
2604                         parse_init_declarator_rest(declaration);
2605                 }
2606
2607                 if(token.type != ',')
2608                         break;
2609                 eat(',');
2610
2611                 ndeclaration = parse_declarator(specifiers, /*may_be_abstract=*/false);
2612         }
2613         expect_void(';');
2614 }
2615
2616 static declaration_t *finished_kr_declaration(declaration_t *declaration)
2617 {
2618         symbol_t *symbol  = declaration->symbol;
2619         if(symbol == NULL) {
2620                 errorf(HERE, "anonymous declaration not valid as function parameter");
2621                 return declaration;
2622         }
2623         namespace_t namespc = (namespace_t) declaration->namespc;
2624         if(namespc != NAMESPACE_NORMAL) {
2625                 return record_declaration(declaration);
2626         }
2627
2628         declaration_t *previous_declaration = get_declaration(symbol, namespc);
2629         if(previous_declaration == NULL ||
2630                         previous_declaration->parent_scope != scope) {
2631                 errorf(HERE, "expected declaration of a function parameter, found '%Y'",
2632                        symbol);
2633                 return declaration;
2634         }
2635
2636         if(previous_declaration->type == NULL) {
2637                 previous_declaration->type          = declaration->type;
2638                 previous_declaration->storage_class = declaration->storage_class;
2639                 previous_declaration->parent_scope  = scope;
2640                 return previous_declaration;
2641         } else {
2642                 return record_declaration(declaration);
2643         }
2644 }
2645
2646 static void parse_declaration(parsed_declaration_func finished_declaration)
2647 {
2648         declaration_specifiers_t specifiers;
2649         memset(&specifiers, 0, sizeof(specifiers));
2650         parse_declaration_specifiers(&specifiers);
2651
2652         if(token.type == ';') {
2653                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
2654         } else {
2655                 declaration_t *declaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2656                 parse_declaration_rest(declaration, &specifiers, finished_declaration);
2657         }
2658 }
2659
2660 static void parse_kr_declaration_list(declaration_t *declaration)
2661 {
2662         type_t *type = skip_typeref(declaration->type);
2663         if(!is_type_function(type))
2664                 return;
2665
2666         if(!type->function.kr_style_parameters)
2667                 return;
2668
2669         /* push function parameters */
2670         int       top        = environment_top();
2671         scope_t  *last_scope = scope;
2672         set_scope(&declaration->scope);
2673
2674         declaration_t *parameter = declaration->scope.declarations;
2675         for( ; parameter != NULL; parameter = parameter->next) {
2676                 assert(parameter->parent_scope == NULL);
2677                 parameter->parent_scope = scope;
2678                 environment_push(parameter);
2679         }
2680
2681         /* parse declaration list */
2682         while(is_declaration_specifier(&token, false)) {
2683                 parse_declaration(finished_kr_declaration);
2684         }
2685
2686         /* pop function parameters */
2687         assert(scope == &declaration->scope);
2688         set_scope(last_scope);
2689         environment_pop_to(top);
2690
2691         /* update function type */
2692         type_t *new_type = duplicate_type(type);
2693         new_type->function.kr_style_parameters = false;
2694
2695         function_parameter_t *parameters     = NULL;
2696         function_parameter_t *last_parameter = NULL;
2697
2698         declaration_t *parameter_declaration = declaration->scope.declarations;
2699         for( ; parameter_declaration != NULL;
2700                         parameter_declaration = parameter_declaration->next) {
2701                 type_t *parameter_type = parameter_declaration->type;
2702                 if(parameter_type == NULL) {
2703                         if (strict_mode) {
2704                                 errorf(HERE, "no type specified for function parameter '%Y'",
2705                                        parameter_declaration->symbol);
2706                         } else {
2707                                 if (warning.implicit_int) {
2708                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
2709                                                 parameter_declaration->symbol);
2710                                 }
2711                                 parameter_type              = type_int;
2712                                 parameter_declaration->type = parameter_type;
2713                         }
2714                 }
2715
2716                 semantic_parameter(parameter_declaration);
2717                 parameter_type = parameter_declaration->type;
2718
2719                 function_parameter_t *function_parameter
2720                         = obstack_alloc(type_obst, sizeof(function_parameter[0]));
2721                 memset(function_parameter, 0, sizeof(function_parameter[0]));
2722
2723                 function_parameter->type = parameter_type;
2724                 if(last_parameter != NULL) {
2725                         last_parameter->next = function_parameter;
2726                 } else {
2727                         parameters = function_parameter;
2728                 }
2729                 last_parameter = function_parameter;
2730         }
2731         new_type->function.parameters = parameters;
2732
2733         type = typehash_insert(new_type);
2734         if(type != new_type) {
2735                 obstack_free(type_obst, new_type);
2736         }
2737
2738         declaration->type = type;
2739 }
2740
2741 static bool first_err = true;
2742
2743 /**
2744  * When called with first_err set, prints the name of the current function,
2745  * else does noting.
2746  */
2747 static void print_in_function(void) {
2748         if (first_err) {
2749                 first_err = false;
2750                 diagnosticf("%s: In function '%Y':\n",
2751                         current_function->source_position.input_name,
2752                         current_function->symbol);
2753         }
2754 }
2755
2756 /**
2757  * Check if all labels are defined in the current function.
2758  * Check if all labels are used in the current function.
2759  */
2760 static void check_labels(void)
2761 {
2762         for (const goto_statement_t *goto_statement = goto_first;
2763             goto_statement != NULL;
2764             goto_statement = goto_statement->next) {
2765                 declaration_t *label = goto_statement->label;
2766
2767                 label->used = true;
2768                 if (label->source_position.input_name == NULL) {
2769                         print_in_function();
2770                         errorf(goto_statement->base.source_position,
2771                                "label '%Y' used but not defined", label->symbol);
2772                  }
2773         }
2774         goto_first = goto_last = NULL;
2775
2776         if (warning.unused_label) {
2777                 for (const label_statement_t *label_statement = label_first;
2778                          label_statement != NULL;
2779                          label_statement = label_statement->next) {
2780                         const declaration_t *label = label_statement->label;
2781
2782                         if (! label->used) {
2783                                 print_in_function();
2784                                 warningf(label_statement->base.source_position,
2785                                         "label '%Y' defined but not used", label->symbol);
2786                         }
2787                 }
2788         }
2789         label_first = label_last = NULL;
2790 }
2791
2792 /**
2793  * Check declarations of current_function for unused entities.
2794  */
2795 static void check_declarations(void)
2796 {
2797         if (warning.unused_parameter) {
2798                 const scope_t *scope = &current_function->scope;
2799
2800                 const declaration_t *parameter = scope->declarations;
2801                 for (; parameter != NULL; parameter = parameter->next) {
2802                         if (! parameter->used) {
2803                                 print_in_function();
2804                                 warningf(parameter->source_position,
2805                                         "unused parameter '%Y'", parameter->symbol);
2806                         }
2807                 }
2808         }
2809         if (warning.unused_variable) {
2810         }
2811 }
2812
2813 static void parse_external_declaration(void)
2814 {
2815         /* function-definitions and declarations both start with declaration
2816          * specifiers */
2817         declaration_specifiers_t specifiers;
2818         memset(&specifiers, 0, sizeof(specifiers));
2819         parse_declaration_specifiers(&specifiers);
2820
2821         /* must be a declaration */
2822         if(token.type == ';') {
2823                 parse_anonymous_declaration_rest(&specifiers, append_declaration);
2824                 return;
2825         }
2826
2827         /* declarator is common to both function-definitions and declarations */
2828         declaration_t *ndeclaration = parse_declarator(&specifiers, /*may_be_abstract=*/false);
2829
2830         /* must be a declaration */
2831         if(token.type == ',' || token.type == '=' || token.type == ';') {
2832                 parse_declaration_rest(ndeclaration, &specifiers, record_declaration);
2833                 return;
2834         }
2835
2836         /* must be a function definition */
2837         parse_kr_declaration_list(ndeclaration);
2838
2839         if(token.type != '{') {
2840                 parse_error_expected("while parsing function definition", '{', 0);
2841                 eat_statement();
2842                 return;
2843         }
2844
2845         type_t *type = ndeclaration->type;
2846
2847         /* note that we don't skip typerefs: the standard doesn't allow them here
2848          * (so we can't use is_type_function here) */
2849         if(type->kind != TYPE_FUNCTION) {
2850                 if (is_type_valid(type)) {
2851                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
2852                                type, ndeclaration->symbol);
2853                 }
2854                 eat_block();
2855                 return;
2856         }
2857
2858         /* § 6.7.5.3 (14) a function definition with () means no
2859          * parameters (and not unspecified parameters) */
2860         if(type->function.unspecified_parameters) {
2861                 type_t *duplicate = duplicate_type(type);
2862                 duplicate->function.unspecified_parameters = false;
2863
2864                 type = typehash_insert(duplicate);
2865                 if(type != duplicate) {
2866                         obstack_free(type_obst, duplicate);
2867                 }
2868                 ndeclaration->type = type;
2869         }
2870
2871         declaration_t *const declaration = record_function_definition(ndeclaration);
2872         if(ndeclaration != declaration) {
2873                 declaration->scope = ndeclaration->scope;
2874         }
2875         type = skip_typeref(declaration->type);
2876
2877         /* push function parameters and switch scope */
2878         int       top        = environment_top();
2879         scope_t  *last_scope = scope;
2880         set_scope(&declaration->scope);
2881
2882         declaration_t *parameter = declaration->scope.declarations;
2883         for( ; parameter != NULL; parameter = parameter->next) {
2884                 if(parameter->parent_scope == &ndeclaration->scope) {
2885                         parameter->parent_scope = scope;
2886                 }
2887                 assert(parameter->parent_scope == NULL
2888                                 || parameter->parent_scope == scope);
2889                 parameter->parent_scope = scope;
2890                 environment_push(parameter);
2891         }
2892
2893         if(declaration->init.statement != NULL) {
2894                 parser_error_multiple_definition(declaration, token.source_position);
2895                 eat_block();
2896                 goto end_of_parse_external_declaration;
2897         } else {
2898                 /* parse function body */
2899                 int            label_stack_top      = label_top();
2900                 declaration_t *old_current_function = current_function;
2901                 current_function                    = declaration;
2902
2903                 declaration->init.statement = parse_compound_statement();
2904                 first_err = true;
2905                 check_labels();
2906                 check_declarations();
2907
2908                 assert(current_function == declaration);
2909                 current_function = old_current_function;
2910                 label_pop_to(label_stack_top);
2911         }
2912
2913 end_of_parse_external_declaration:
2914         assert(scope == &declaration->scope);
2915         set_scope(last_scope);
2916         environment_pop_to(top);
2917 }
2918
2919 static type_t *make_bitfield_type(type_t *base, expression_t *size)
2920 {
2921         type_t *type        = allocate_type_zero(TYPE_BITFIELD);
2922         type->bitfield.base = base;
2923         type->bitfield.size = size;
2924
2925         return type;
2926 }
2927
2928 static void parse_compound_declarators(declaration_t *struct_declaration,
2929                 const declaration_specifiers_t *specifiers)
2930 {
2931         declaration_t *last_declaration = struct_declaration->scope.declarations;
2932         if(last_declaration != NULL) {
2933                 while(last_declaration->next != NULL) {
2934                         last_declaration = last_declaration->next;
2935                 }
2936         }
2937
2938         while(1) {
2939                 declaration_t *declaration;
2940
2941                 if(token.type == ':') {
2942                         next_token();
2943
2944                         type_t *base_type = specifiers->type;
2945                         expression_t *size = parse_constant_expression();
2946
2947                         if(!is_type_integer(skip_typeref(base_type))) {
2948                                 errorf(HERE, "bitfield base type '%T' is not an integer type",
2949                                        base_type);
2950                         }
2951
2952                         type_t *type = make_bitfield_type(base_type, size);
2953
2954                         declaration                  = allocate_declaration_zero();
2955                         declaration->namespc         = NAMESPACE_NORMAL;
2956                         declaration->storage_class   = STORAGE_CLASS_NONE;
2957                         declaration->source_position = token.source_position;
2958                         declaration->modifiers       = specifiers->decl_modifiers;
2959                         declaration->type            = type;
2960                 } else {
2961                         declaration = parse_declarator(specifiers,/*may_be_abstract=*/true);
2962
2963                         type_t *orig_type = declaration->type;
2964                         type_t *type      = skip_typeref(orig_type);
2965
2966                         if(token.type == ':') {
2967                                 next_token();
2968                                 expression_t *size = parse_constant_expression();
2969
2970                                 if(!is_type_integer(type)) {
2971                                         errorf(HERE, "bitfield base type '%T' is not an "
2972                                                "integer type", orig_type);
2973                                 }
2974
2975                                 type_t *bitfield_type = make_bitfield_type(orig_type, size);
2976                                 declaration->type = bitfield_type;
2977                         } else {
2978                                 /* TODO we ignore arrays for now... what is missing is a check
2979                                  * that they're at the end of the struct */
2980                                 if(is_type_incomplete(type) && !is_type_array(type)) {
2981                                         errorf(HERE,
2982                                                "compound member '%Y' has incomplete type '%T'",
2983                                                declaration->symbol, orig_type);
2984                                 } else if(is_type_function(type)) {
2985                                         errorf(HERE, "compound member '%Y' must not have function "
2986                                                "type '%T'", declaration->symbol, orig_type);
2987                                 }
2988                         }
2989                 }
2990
2991                 /* make sure we don't define a symbol multiple times */
2992                 symbol_t *symbol = declaration->symbol;
2993                 if(symbol != NULL) {
2994                         declaration_t *iter = struct_declaration->scope.declarations;
2995                         for( ; iter != NULL; iter = iter->next) {
2996                                 if(iter->symbol == symbol) {
2997                                         errorf(declaration->source_position,
2998                                                "multiple declarations of symbol '%Y'", symbol);
2999                                         errorf(iter->source_position,
3000                                                "previous declaration of '%Y' was here", symbol);
3001                                         break;
3002                                 }
3003                         }
3004                 }
3005
3006                 /* append declaration */
3007                 if(last_declaration != NULL) {
3008                         last_declaration->next = declaration;
3009                 } else {
3010                         struct_declaration->scope.declarations = declaration;
3011                 }
3012                 last_declaration = declaration;
3013
3014                 if(token.type != ',')
3015                         break;
3016                 next_token();
3017         }
3018         expect_void(';');
3019 }
3020
3021 static void parse_compound_type_entries(declaration_t *compound_declaration)
3022 {
3023         eat('{');
3024
3025         while(token.type != '}' && token.type != T_EOF) {
3026                 declaration_specifiers_t specifiers;
3027                 memset(&specifiers, 0, sizeof(specifiers));
3028                 parse_declaration_specifiers(&specifiers);
3029
3030                 parse_compound_declarators(compound_declaration, &specifiers);
3031         }
3032         if(token.type == T_EOF) {
3033                 errorf(HERE, "EOF while parsing struct");
3034         }
3035         next_token();
3036 }
3037
3038 static type_t *parse_typename(void)
3039 {
3040         declaration_specifiers_t specifiers;
3041         memset(&specifiers, 0, sizeof(specifiers));
3042         parse_declaration_specifiers(&specifiers);
3043         if(specifiers.storage_class != STORAGE_CLASS_NONE) {
3044                 /* TODO: improve error message, user does probably not know what a
3045                  * storage class is...
3046                  */
3047                 errorf(HERE, "typename may not have a storage class");
3048         }
3049
3050         type_t *result = parse_abstract_declarator(specifiers.type);
3051
3052         return result;
3053 }
3054
3055
3056
3057
3058 typedef expression_t* (*parse_expression_function) (unsigned precedence);
3059 typedef expression_t* (*parse_expression_infix_function) (unsigned precedence,
3060                                                           expression_t *left);
3061
3062 typedef struct expression_parser_function_t expression_parser_function_t;
3063 struct expression_parser_function_t {
3064         unsigned                         precedence;
3065         parse_expression_function        parser;
3066         unsigned                         infix_precedence;
3067         parse_expression_infix_function  infix_parser;
3068 };
3069
3070 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
3071
3072 /**
3073  * Creates a new invalid expression.
3074  */
3075 static expression_t *create_invalid_expression(void)
3076 {
3077         expression_t *expression         = allocate_expression_zero(EXPR_INVALID);
3078         expression->base.source_position = token.source_position;
3079         return expression;
3080 }
3081
3082 /**
3083  * Prints an error message if an expression was expected but not read
3084  */
3085 static expression_t *expected_expression_error(void)
3086 {
3087         /* skip the error message if the error token was read */
3088         if (token.type != T_ERROR) {
3089                 errorf(HERE, "expected expression, got token '%K'", &token);
3090         }
3091         next_token();
3092
3093         return create_invalid_expression();
3094 }
3095
3096 /**
3097  * Parse a string constant.
3098  */
3099 static expression_t *parse_string_const(void)
3100 {
3101         expression_t *cnst = allocate_expression_zero(EXPR_STRING_LITERAL);
3102         cnst->base.type    = type_char_ptr;
3103         cnst->string.value = parse_string_literals();
3104
3105         return cnst;
3106 }
3107
3108 /**
3109  * Parse a wide string constant.
3110  */
3111 static expression_t *parse_wide_string_const(void)
3112 {
3113         expression_t *const cnst = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
3114         cnst->base.type         = type_wchar_t_ptr;
3115         cnst->wide_string.value = token.v.wide_string; /* TODO concatenate */
3116         next_token();
3117         return cnst;
3118 }
3119
3120 /**
3121  * Parse an integer constant.
3122  */
3123 static expression_t *parse_int_const(void)
3124 {
3125         expression_t *cnst       = allocate_expression_zero(EXPR_CONST);
3126         cnst->base.type          = token.datatype;
3127         cnst->conste.v.int_value = token.v.intvalue;
3128
3129         next_token();
3130
3131         return cnst;
3132 }
3133
3134 /**
3135  * Parse a float constant.
3136  */
3137 static expression_t *parse_float_const(void)
3138 {
3139         expression_t *cnst         = allocate_expression_zero(EXPR_CONST);
3140         cnst->base.type            = token.datatype;
3141         cnst->conste.v.float_value = token.v.floatvalue;
3142
3143         next_token();
3144
3145         return cnst;
3146 }
3147
3148 static declaration_t *create_implicit_function(symbol_t *symbol,
3149                 const source_position_t source_position)
3150 {
3151         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
3152         ntype->function.return_type            = type_int;
3153         ntype->function.unspecified_parameters = true;
3154
3155         type_t *type = typehash_insert(ntype);
3156         if(type != ntype) {
3157                 free_type(ntype);
3158         }
3159
3160         declaration_t *const declaration = allocate_declaration_zero();
3161         declaration->storage_class   = STORAGE_CLASS_EXTERN;
3162         declaration->type            = type;
3163         declaration->symbol          = symbol;
3164         declaration->source_position = source_position;
3165         declaration->parent_scope  = global_scope;
3166
3167         scope_t *old_scope = scope;
3168         set_scope(global_scope);
3169
3170         environment_push(declaration);
3171         /* prepends the declaration to the global declarations list */
3172         declaration->next   = scope->declarations;
3173         scope->declarations = declaration;
3174
3175         assert(scope == global_scope);
3176         set_scope(old_scope);
3177
3178         return declaration;
3179 }
3180
3181 /**
3182  * Creates a return_type (func)(argument_type) function type if not
3183  * already exists.
3184  *
3185  * @param return_type    the return type
3186  * @param argument_type  the argument type
3187  */
3188 static type_t *make_function_1_type(type_t *return_type, type_t *argument_type)
3189 {
3190         function_parameter_t *parameter
3191                 = obstack_alloc(type_obst, sizeof(parameter[0]));
3192         memset(parameter, 0, sizeof(parameter[0]));
3193         parameter->type = argument_type;
3194
3195         type_t *type               = allocate_type_zero(TYPE_FUNCTION);
3196         type->function.return_type = return_type;
3197         type->function.parameters  = parameter;
3198
3199         type_t *result = typehash_insert(type);
3200         if(result != type) {
3201                 free_type(type);
3202         }
3203
3204         return result;
3205 }
3206
3207 /**
3208  * Creates a function type for some function like builtins.
3209  *
3210  * @param symbol   the symbol describing the builtin
3211  */
3212 static type_t *get_builtin_symbol_type(symbol_t *symbol)
3213 {
3214         switch(symbol->ID) {
3215         case T___builtin_alloca:
3216                 return make_function_1_type(type_void_ptr, type_size_t);
3217         case T___builtin_nan:
3218                 return make_function_1_type(type_double, type_char_ptr);
3219         case T___builtin_nanf:
3220                 return make_function_1_type(type_float, type_char_ptr);
3221         case T___builtin_nand:
3222                 return make_function_1_type(type_long_double, type_char_ptr);
3223         case T___builtin_va_end:
3224                 return make_function_1_type(type_void, type_valist);
3225         default:
3226                 panic("not implemented builtin symbol found");
3227         }
3228 }
3229
3230 /**
3231  * Performs automatic type cast as described in § 6.3.2.1.
3232  *
3233  * @param orig_type  the original type
3234  */
3235 static type_t *automatic_type_conversion(type_t *orig_type)
3236 {
3237         type_t *type = skip_typeref(orig_type);
3238         if(is_type_array(type)) {
3239                 array_type_t *array_type   = &type->array;
3240                 type_t       *element_type = array_type->element_type;
3241                 unsigned      qualifiers   = array_type->type.qualifiers;
3242
3243                 return make_pointer_type(element_type, qualifiers);
3244         }
3245
3246         if(is_type_function(type)) {
3247                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
3248         }
3249
3250         return orig_type;
3251 }
3252
3253 /**
3254  * reverts the automatic casts of array to pointer types and function
3255  * to function-pointer types as defined § 6.3.2.1
3256  */
3257 type_t *revert_automatic_type_conversion(const expression_t *expression)
3258 {
3259         switch (expression->kind) {
3260                 case EXPR_REFERENCE: return expression->reference.declaration->type;
3261                 case EXPR_SELECT:    return expression->select.compound_entry->type;
3262
3263                 case EXPR_UNARY_DEREFERENCE: {
3264                         const expression_t *const value = expression->unary.value;
3265                         type_t             *const type  = skip_typeref(value->base.type);
3266                         assert(is_type_pointer(type));
3267                         return type->pointer.points_to;
3268                 }
3269
3270                 case EXPR_BUILTIN_SYMBOL:
3271                         return get_builtin_symbol_type(expression->builtin_symbol.symbol);
3272
3273                 case EXPR_ARRAY_ACCESS: {
3274                         const expression_t *array_ref = expression->array_access.array_ref;
3275                         type_t             *type_left = skip_typeref(array_ref->base.type);
3276                         if (!is_type_valid(type_left))
3277                                 return type_left;
3278                         assert(is_type_pointer(type_left));
3279                         return type_left->pointer.points_to;
3280                 }
3281
3282                 default: break;
3283         }
3284
3285         return expression->base.type;
3286 }
3287
3288 static expression_t *parse_reference(void)
3289 {
3290         expression_t *expression = allocate_expression_zero(EXPR_REFERENCE);
3291
3292         reference_expression_t *ref = &expression->reference;
3293         ref->symbol = token.v.symbol;
3294
3295         declaration_t *declaration = get_declaration(ref->symbol, NAMESPACE_NORMAL);
3296
3297         source_position_t source_position = token.source_position;
3298         next_token();
3299
3300         if(declaration == NULL) {
3301                 if (! strict_mode && token.type == '(') {
3302                         /* an implicitly defined function */
3303                         if (warning.implicit_function_declaration) {
3304                                 warningf(HERE, "implicit declaration of function '%Y'",
3305                                         ref->symbol);
3306                         }
3307
3308                         declaration = create_implicit_function(ref->symbol,
3309                                                                source_position);
3310                 } else {
3311                         errorf(HERE, "unknown symbol '%Y' found.", ref->symbol);
3312                         return expression;
3313                 }
3314         }
3315
3316         type_t *type         = declaration->type;
3317
3318         /* we always do the auto-type conversions; the & and sizeof parser contains
3319          * code to revert this! */
3320         type = automatic_type_conversion(type);
3321
3322         ref->declaration = declaration;
3323         ref->base.type   = type;
3324
3325         /* this declaration is used */
3326         declaration->used = true;
3327
3328         return expression;
3329 }
3330
3331 static void check_cast_allowed(expression_t *expression, type_t *dest_type)
3332 {
3333         (void) expression;
3334         (void) dest_type;
3335         /* TODO check if explicit cast is allowed and issue warnings/errors */
3336 }
3337
3338 static expression_t *parse_cast(void)
3339 {
3340         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
3341
3342         cast->base.source_position = token.source_position;
3343
3344         type_t *type  = parse_typename();
3345
3346         expect(')');
3347         expression_t *value = parse_sub_expression(20);
3348
3349         check_cast_allowed(value, type);
3350
3351         cast->base.type   = type;
3352         cast->unary.value = value;
3353
3354         return cast;
3355 }
3356
3357 static expression_t *parse_statement_expression(void)
3358 {
3359         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
3360
3361         statement_t *statement           = parse_compound_statement();
3362         expression->statement.statement  = statement;
3363         expression->base.source_position = statement->base.source_position;
3364
3365         /* find last statement and use its type */
3366         type_t *type = type_void;
3367         const statement_t *stmt = statement->compound.statements;
3368         if (stmt != NULL) {
3369                 while (stmt->base.next != NULL)
3370                         stmt = stmt->base.next;
3371
3372                 if (stmt->kind == STATEMENT_EXPRESSION) {
3373                         type = stmt->expression.expression->base.type;
3374                 }
3375         } else {
3376                 warningf(expression->base.source_position, "empty statement expression ({})");
3377         }
3378         expression->base.type = type;
3379
3380         expect(')');
3381
3382         return expression;
3383 }
3384
3385 static expression_t *parse_brace_expression(void)
3386 {
3387         eat('(');
3388
3389         switch(token.type) {
3390         case '{':
3391                 /* gcc extension: a statement expression */
3392                 return parse_statement_expression();
3393
3394         TYPE_QUALIFIERS
3395         TYPE_SPECIFIERS
3396                 return parse_cast();
3397         case T_IDENTIFIER:
3398                 if(is_typedef_symbol(token.v.symbol)) {
3399                         return parse_cast();
3400                 }
3401         }
3402
3403         expression_t *result = parse_expression();
3404         expect(')');
3405
3406         return result;
3407 }
3408
3409 static expression_t *parse_function_keyword(void)
3410 {
3411         next_token();
3412         /* TODO */
3413
3414         if (current_function == NULL) {
3415                 errorf(HERE, "'__func__' used outside of a function");
3416         }
3417
3418         expression_t *expression = allocate_expression_zero(EXPR_FUNCTION);
3419         expression->base.type    = type_char_ptr;
3420
3421         return expression;
3422 }
3423
3424 static expression_t *parse_pretty_function_keyword(void)
3425 {
3426         eat(T___PRETTY_FUNCTION__);
3427         /* TODO */
3428
3429         if (current_function == NULL) {
3430                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
3431         }
3432
3433         expression_t *expression = allocate_expression_zero(EXPR_PRETTY_FUNCTION);
3434         expression->base.type    = type_char_ptr;
3435
3436         return expression;
3437 }
3438
3439 static designator_t *parse_designator(void)
3440 {
3441         designator_t *result = allocate_ast_zero(sizeof(result[0]));
3442
3443         if(token.type != T_IDENTIFIER) {
3444                 parse_error_expected("while parsing member designator",
3445                                      T_IDENTIFIER, 0);
3446                 eat_paren();
3447                 return NULL;
3448         }
3449         result->symbol = token.v.symbol;
3450         next_token();
3451
3452         designator_t *last_designator = result;
3453         while(true) {
3454                 if(token.type == '.') {
3455                         next_token();
3456                         if(token.type != T_IDENTIFIER) {
3457                                 parse_error_expected("while parsing member designator",
3458                                                      T_IDENTIFIER, 0);
3459                                 eat_paren();
3460                                 return NULL;
3461                         }
3462                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3463                         designator->symbol       = token.v.symbol;
3464                         next_token();
3465
3466                         last_designator->next = designator;
3467                         last_designator       = designator;
3468                         continue;
3469                 }
3470                 if(token.type == '[') {
3471                         next_token();
3472                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
3473                         designator->array_access = parse_expression();
3474                         if(designator->array_access == NULL) {
3475                                 eat_paren();
3476                                 return NULL;
3477                         }
3478                         expect(']');
3479
3480                         last_designator->next = designator;
3481                         last_designator       = designator;
3482                         continue;
3483                 }
3484                 break;
3485         }
3486
3487         return result;
3488 }
3489
3490 static expression_t *parse_offsetof(void)
3491 {
3492         eat(T___builtin_offsetof);
3493
3494         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
3495         expression->base.type    = type_size_t;
3496
3497         expect('(');
3498         expression->offsetofe.type = parse_typename();
3499         expect(',');
3500         expression->offsetofe.designator = parse_designator();
3501         expect(')');
3502
3503         return expression;
3504 }
3505
3506 static expression_t *parse_va_start(void)
3507 {
3508         eat(T___builtin_va_start);
3509
3510         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
3511
3512         expect('(');
3513         expression->va_starte.ap = parse_assignment_expression();
3514         expect(',');
3515         expression_t *const expr = parse_assignment_expression();
3516         if (expr->kind == EXPR_REFERENCE) {
3517                 declaration_t *const decl = expr->reference.declaration;
3518                 if (decl == NULL)
3519                         return create_invalid_expression();
3520                 if (decl->parent_scope == &current_function->scope &&
3521                     decl->next == NULL) {
3522                         expression->va_starte.parameter = decl;
3523                         expect(')');
3524                         return expression;
3525                 }
3526         }
3527         errorf(expr->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
3528
3529         return create_invalid_expression();
3530 }
3531
3532 static expression_t *parse_va_arg(void)
3533 {
3534         eat(T___builtin_va_arg);
3535
3536         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
3537
3538         expect('(');
3539         expression->va_arge.ap = parse_assignment_expression();
3540         expect(',');
3541         expression->base.type = parse_typename();
3542         expect(')');
3543
3544         return expression;
3545 }
3546
3547 static expression_t *parse_builtin_symbol(void)
3548 {
3549         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_SYMBOL);
3550
3551         symbol_t *symbol = token.v.symbol;
3552
3553         expression->builtin_symbol.symbol = symbol;
3554         next_token();
3555
3556         type_t *type = get_builtin_symbol_type(symbol);
3557         type = automatic_type_conversion(type);
3558
3559         expression->base.type = type;
3560         return expression;
3561 }
3562
3563 static expression_t *parse_builtin_constant(void)
3564 {
3565         eat(T___builtin_constant_p);
3566
3567         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
3568
3569         expect('(');
3570         expression->builtin_constant.value = parse_assignment_expression();
3571         expect(')');
3572         expression->base.type = type_int;
3573
3574         return expression;
3575 }
3576
3577 static expression_t *parse_builtin_prefetch(void)
3578 {
3579         eat(T___builtin_prefetch);
3580
3581         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_PREFETCH);
3582
3583         expect('(');
3584         expression->builtin_prefetch.adr = parse_assignment_expression();
3585         if (token.type == ',') {
3586                 next_token();
3587                 expression->builtin_prefetch.rw = parse_assignment_expression();
3588         }
3589         if (token.type == ',') {
3590                 next_token();
3591                 expression->builtin_prefetch.locality = parse_assignment_expression();
3592         }
3593         expect(')');
3594         expression->base.type = type_void;
3595
3596         return expression;
3597 }
3598
3599 static expression_t *parse_compare_builtin(void)
3600 {
3601         expression_t *expression;
3602
3603         switch(token.type) {
3604         case T___builtin_isgreater:
3605                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
3606                 break;
3607         case T___builtin_isgreaterequal:
3608                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
3609                 break;
3610         case T___builtin_isless:
3611                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
3612                 break;
3613         case T___builtin_islessequal:
3614                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
3615                 break;
3616         case T___builtin_islessgreater:
3617                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
3618                 break;
3619         case T___builtin_isunordered:
3620                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
3621                 break;
3622         default:
3623                 panic("invalid compare builtin found");
3624                 break;
3625         }
3626         expression->base.source_position = HERE;
3627         next_token();
3628
3629         expect('(');
3630         expression->binary.left = parse_assignment_expression();
3631         expect(',');
3632         expression->binary.right = parse_assignment_expression();
3633         expect(')');
3634
3635         type_t *const orig_type_left  = expression->binary.left->base.type;
3636         type_t *const orig_type_right = expression->binary.right->base.type;
3637
3638         type_t *const type_left  = skip_typeref(orig_type_left);
3639         type_t *const type_right = skip_typeref(orig_type_right);
3640         if(!is_type_float(type_left) && !is_type_float(type_right)) {
3641                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
3642                         type_error_incompatible("invalid operands in comparison",
3643                                 expression->base.source_position, orig_type_left, orig_type_right);
3644                 }
3645         } else {
3646                 semantic_comparison(&expression->binary);
3647         }
3648
3649         return expression;
3650 }
3651
3652 static expression_t *parse_builtin_expect(void)
3653 {
3654         eat(T___builtin_expect);
3655
3656         expression_t *expression
3657                 = allocate_expression_zero(EXPR_BINARY_BUILTIN_EXPECT);
3658
3659         expect('(');
3660         expression->binary.left = parse_assignment_expression();
3661         expect(',');
3662         expression->binary.right = parse_constant_expression();
3663         expect(')');
3664
3665         expression->base.type = expression->binary.left->base.type;
3666
3667         return expression;
3668 }
3669
3670 static expression_t *parse_assume(void) {
3671         eat(T_assume);
3672
3673         expression_t *expression
3674                 = allocate_expression_zero(EXPR_UNARY_ASSUME);
3675
3676         expect('(');
3677         expression->unary.value = parse_assignment_expression();
3678         expect(')');
3679
3680         expression->base.type = type_void;
3681         return expression;
3682 }
3683
3684 static expression_t *parse_primary_expression(void)
3685 {
3686         switch(token.type) {
3687         case T_INTEGER:
3688                 return parse_int_const();
3689         case T_FLOATINGPOINT:
3690                 return parse_float_const();
3691         case T_STRING_LITERAL:
3692                 return parse_string_const();
3693         case T_WIDE_STRING_LITERAL:
3694                 return parse_wide_string_const();
3695         case T_IDENTIFIER:
3696                 return parse_reference();
3697         case T___FUNCTION__:
3698         case T___func__:
3699                 return parse_function_keyword();
3700         case T___PRETTY_FUNCTION__:
3701                 return parse_pretty_function_keyword();
3702         case T___builtin_offsetof:
3703                 return parse_offsetof();
3704         case T___builtin_va_start:
3705                 return parse_va_start();
3706         case T___builtin_va_arg:
3707                 return parse_va_arg();
3708         case T___builtin_expect:
3709                 return parse_builtin_expect();
3710         case T___builtin_alloca:
3711         case T___builtin_nan:
3712         case T___builtin_nand:
3713         case T___builtin_nanf:
3714         case T___builtin_va_end:
3715                 return parse_builtin_symbol();
3716         case T___builtin_isgreater:
3717         case T___builtin_isgreaterequal:
3718         case T___builtin_isless:
3719         case T___builtin_islessequal:
3720         case T___builtin_islessgreater:
3721         case T___builtin_isunordered:
3722                 return parse_compare_builtin();
3723         case T___builtin_constant_p:
3724                 return parse_builtin_constant();
3725         case T___builtin_prefetch:
3726                 return parse_builtin_prefetch();
3727         case T_assume:
3728                 return parse_assume();
3729
3730         case '(':
3731                 return parse_brace_expression();
3732         }
3733
3734         errorf(HERE, "unexpected token '%K'", &token);
3735         eat_statement();
3736
3737         return create_invalid_expression();
3738 }
3739
3740 /**
3741  * Check if the expression has the character type and issue a warning then.
3742  */
3743 static void check_for_char_index_type(const expression_t *expression) {
3744         type_t       *const type      = expression->base.type;
3745         const type_t *const base_type = skip_typeref(type);
3746
3747         if (is_type_atomic(base_type, ATOMIC_TYPE_CHAR) &&
3748                         warning.char_subscripts) {
3749                 warningf(expression->base.source_position,
3750                         "array subscript has type '%T'", type);
3751         }
3752 }
3753
3754 static expression_t *parse_array_expression(unsigned precedence,
3755                                             expression_t *left)
3756 {
3757         (void) precedence;
3758
3759         eat('[');
3760
3761         expression_t *inside = parse_expression();
3762
3763         expression_t *expression = allocate_expression_zero(EXPR_ARRAY_ACCESS);
3764
3765         array_access_expression_t *array_access = &expression->array_access;
3766
3767         type_t *const orig_type_left   = left->base.type;
3768         type_t *const orig_type_inside = inside->base.type;
3769
3770         type_t *const type_left   = skip_typeref(orig_type_left);
3771         type_t *const type_inside = skip_typeref(orig_type_inside);
3772
3773         type_t *return_type;
3774         if (is_type_pointer(type_left)) {
3775                 return_type             = type_left->pointer.points_to;
3776                 array_access->array_ref = left;
3777                 array_access->index     = inside;
3778                 check_for_char_index_type(inside);
3779         } else if (is_type_pointer(type_inside)) {
3780                 return_type             = type_inside->pointer.points_to;
3781                 array_access->array_ref = inside;
3782                 array_access->index     = left;
3783                 array_access->flipped   = true;
3784                 check_for_char_index_type(left);
3785         } else {
3786                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
3787                         errorf(HERE,
3788                                 "array access on object with non-pointer types '%T', '%T'",
3789                                 orig_type_left, orig_type_inside);
3790                 }
3791                 return_type             = type_error_type;
3792                 array_access->array_ref = create_invalid_expression();
3793         }
3794
3795         if(token.type != ']') {
3796                 parse_error_expected("Problem while parsing array access", ']', 0);
3797                 return expression;
3798         }
3799         next_token();
3800
3801         return_type           = automatic_type_conversion(return_type);
3802         expression->base.type = return_type;
3803
3804         return expression;
3805 }
3806
3807 static expression_t *parse_typeprop(expression_kind_t kind, unsigned precedence)
3808 {
3809         expression_t *tp_expression = allocate_expression_zero(kind);
3810         tp_expression->base.type    = type_size_t;
3811
3812         if(token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
3813                 next_token();
3814                 tp_expression->typeprop.type = parse_typename();
3815                 expect(')');
3816         } else {
3817                 expression_t *expression = parse_sub_expression(precedence);
3818                 expression->base.type    = revert_automatic_type_conversion(expression);
3819
3820                 tp_expression->typeprop.type          = expression->base.type;
3821                 tp_expression->typeprop.tp_expression = expression;
3822         }
3823
3824         return tp_expression;
3825 }
3826
3827 static expression_t *parse_sizeof(unsigned precedence)
3828 {
3829         eat(T_sizeof);
3830         return parse_typeprop(EXPR_SIZEOF, precedence);
3831 }
3832
3833 static expression_t *parse_alignof(unsigned precedence)
3834 {
3835         eat(T___alignof__);
3836         return parse_typeprop(EXPR_SIZEOF, precedence);
3837 }
3838
3839 static expression_t *parse_select_expression(unsigned precedence,
3840                                              expression_t *compound)
3841 {
3842         (void) precedence;
3843         assert(token.type == '.' || token.type == T_MINUSGREATER);
3844
3845         bool is_pointer = (token.type == T_MINUSGREATER);
3846         next_token();
3847
3848         expression_t *select    = allocate_expression_zero(EXPR_SELECT);
3849         select->select.compound = compound;
3850
3851         if(token.type != T_IDENTIFIER) {
3852                 parse_error_expected("while parsing select", T_IDENTIFIER, 0);
3853                 return select;
3854         }
3855         symbol_t *symbol      = token.v.symbol;
3856         select->select.symbol = symbol;
3857         next_token();
3858
3859         type_t *const orig_type = compound->base.type;
3860         type_t *const type      = skip_typeref(orig_type);
3861
3862         type_t *type_left = type;
3863         if(is_pointer) {
3864                 if (!is_type_pointer(type)) {
3865                         if (is_type_valid(type)) {
3866                                 errorf(HERE, "left hand side of '->' is not a pointer, but '%T'", orig_type);
3867                         }
3868                         return create_invalid_expression();
3869                 }
3870                 type_left = type->pointer.points_to;
3871         }
3872         type_left = skip_typeref(type_left);
3873
3874         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
3875             type_left->kind != TYPE_COMPOUND_UNION) {
3876                 if (is_type_valid(type_left)) {
3877                         errorf(HERE, "request for member '%Y' in something not a struct or "
3878                                "union, but '%T'", symbol, type_left);
3879                 }
3880                 return create_invalid_expression();
3881         }
3882
3883         declaration_t *const declaration = type_left->compound.declaration;
3884
3885         if(!declaration->init.is_defined) {
3886                 errorf(HERE, "request for member '%Y' of incomplete type '%T'",
3887                        symbol, type_left);
3888                 return create_invalid_expression();
3889         }
3890
3891         declaration_t *iter = declaration->scope.declarations;
3892         for( ; iter != NULL; iter = iter->next) {
3893                 if(iter->symbol == symbol) {
3894                         break;
3895                 }
3896         }
3897         if(iter == NULL) {
3898                 errorf(HERE, "'%T' has no member named '%Y'", orig_type, symbol);
3899                 return create_invalid_expression();
3900         }
3901
3902         /* we always do the auto-type conversions; the & and sizeof parser contains
3903          * code to revert this! */
3904         type_t *expression_type = automatic_type_conversion(iter->type);
3905
3906         select->select.compound_entry = iter;
3907         select->base.type             = expression_type;
3908
3909         if(expression_type->kind == TYPE_BITFIELD) {
3910                 expression_t *extract
3911                         = allocate_expression_zero(EXPR_UNARY_BITFIELD_EXTRACT);
3912                 extract->unary.value = select;
3913                 extract->base.type   = expression_type->bitfield.base;
3914
3915                 return extract;
3916         }
3917
3918         return select;
3919 }
3920
3921 /**
3922  * Parse a call expression, ie. expression '( ... )'.
3923  *
3924  * @param expression  the function address
3925  */
3926 static expression_t *parse_call_expression(unsigned precedence,
3927                                            expression_t *expression)
3928 {
3929         (void) precedence;
3930         expression_t *result = allocate_expression_zero(EXPR_CALL);
3931
3932         call_expression_t *call = &result->call;
3933         call->function          = expression;
3934
3935         type_t *const orig_type = expression->base.type;
3936         type_t *const type      = skip_typeref(orig_type);
3937
3938         function_type_t *function_type = NULL;
3939         if (is_type_pointer(type)) {
3940                 type_t *const to_type = skip_typeref(type->pointer.points_to);
3941
3942                 if (is_type_function(to_type)) {
3943                         function_type   = &to_type->function;
3944                         call->base.type = function_type->return_type;
3945                 }
3946         }
3947
3948         if (function_type == NULL && is_type_valid(type)) {
3949                 errorf(HERE, "called object '%E' (type '%T') is not a pointer to a function", expression, orig_type);
3950         }
3951
3952         /* parse arguments */
3953         eat('(');
3954
3955         if(token.type != ')') {
3956                 call_argument_t *last_argument = NULL;
3957
3958                 while(true) {
3959                         call_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
3960
3961                         argument->expression = parse_assignment_expression();
3962                         if(last_argument == NULL) {
3963                                 call->arguments = argument;
3964                         } else {
3965                                 last_argument->next = argument;
3966                         }
3967                         last_argument = argument;
3968
3969                         if(token.type != ',')
3970                                 break;
3971                         next_token();
3972                 }
3973         }
3974         expect(')');
3975
3976         if(function_type != NULL) {
3977                 function_parameter_t *parameter = function_type->parameters;
3978                 call_argument_t      *argument  = call->arguments;
3979                 for( ; parameter != NULL && argument != NULL;
3980                                 parameter = parameter->next, argument = argument->next) {
3981                         type_t *expected_type = parameter->type;
3982                         /* TODO report scope in error messages */
3983                         expression_t *const arg_expr = argument->expression;
3984                         type_t       *const res_type = semantic_assign(expected_type, arg_expr, "function call");
3985                         if (res_type == NULL) {
3986                                 /* TODO improve error message */
3987                                 errorf(arg_expr->base.source_position,
3988                                         "Cannot call function with argument '%E' of type '%T' where type '%T' is expected",
3989                                         arg_expr, arg_expr->base.type, expected_type);
3990                         } else {
3991                                 argument->expression = create_implicit_cast(argument->expression, expected_type);
3992                         }
3993                 }
3994                 /* too few parameters */
3995                 if(parameter != NULL) {
3996                         errorf(HERE, "too few arguments to function '%E'", expression);
3997                 } else if(argument != NULL) {
3998                         /* too many parameters */
3999                         if(!function_type->variadic
4000                                         && !function_type->unspecified_parameters) {
4001                                 errorf(HERE, "too many arguments to function '%E'", expression);
4002                         } else {
4003                                 /* do default promotion */
4004                                 for( ; argument != NULL; argument = argument->next) {
4005                                         type_t *type = argument->expression->base.type;
4006
4007                                         type = skip_typeref(type);
4008                                         if(is_type_integer(type)) {
4009                                                 type = promote_integer(type);
4010                                         } else if(type == type_float) {
4011                                                 type = type_double;
4012                                         }
4013
4014                                         argument->expression
4015                                                 = create_implicit_cast(argument->expression, type);
4016                                 }
4017
4018                                 check_format(&result->call);
4019                         }
4020                 } else {
4021                         check_format(&result->call);
4022                 }
4023         }
4024
4025         return result;
4026 }
4027
4028 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
4029
4030 static bool same_compound_type(const type_t *type1, const type_t *type2)
4031 {
4032         return
4033                 is_type_compound(type1) &&
4034                 type1->kind == type2->kind &&
4035                 type1->compound.declaration == type2->compound.declaration;
4036 }
4037
4038 /**
4039  * Parse a conditional expression, ie. 'expression ? ... : ...'.
4040  *
4041  * @param expression  the conditional expression
4042  */
4043 static expression_t *parse_conditional_expression(unsigned precedence,
4044                                                   expression_t *expression)
4045 {
4046         eat('?');
4047
4048         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
4049
4050         conditional_expression_t *conditional = &result->conditional;
4051         conditional->condition = expression;
4052
4053         /* 6.5.15.2 */
4054         type_t *const condition_type_orig = expression->base.type;
4055         type_t *const condition_type      = skip_typeref(condition_type_orig);
4056         if (!is_type_scalar(condition_type) && is_type_valid(condition_type)) {
4057                 type_error("expected a scalar type in conditional condition",
4058                            expression->base.source_position, condition_type_orig);
4059         }
4060
4061         expression_t *true_expression = parse_expression();
4062         expect(':');
4063         expression_t *false_expression = parse_sub_expression(precedence);
4064
4065         conditional->true_expression  = true_expression;
4066         conditional->false_expression = false_expression;
4067
4068         type_t *const orig_true_type  = true_expression->base.type;
4069         type_t *const orig_false_type = false_expression->base.type;
4070         type_t *const true_type       = skip_typeref(orig_true_type);
4071         type_t *const false_type      = skip_typeref(orig_false_type);
4072
4073         /* 6.5.15.3 */
4074         type_t *result_type;
4075         if (is_type_arithmetic(true_type) && is_type_arithmetic(false_type)) {
4076                 result_type = semantic_arithmetic(true_type, false_type);
4077
4078                 true_expression  = create_implicit_cast(true_expression, result_type);
4079                 false_expression = create_implicit_cast(false_expression, result_type);
4080
4081                 conditional->true_expression  = true_expression;
4082                 conditional->false_expression = false_expression;
4083                 conditional->base.type        = result_type;
4084         } else if (same_compound_type(true_type, false_type) || (
4085             is_type_atomic(true_type, ATOMIC_TYPE_VOID) &&
4086             is_type_atomic(false_type, ATOMIC_TYPE_VOID)
4087                 )) {
4088                 /* just take 1 of the 2 types */
4089                 result_type = true_type;
4090         } else if (is_type_pointer(true_type) && is_type_pointer(false_type)
4091                         && pointers_compatible(true_type, false_type)) {
4092                 /* ok */
4093                 result_type = true_type;
4094         } else {
4095                 /* TODO */
4096                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
4097                         type_error_incompatible("while parsing conditional",
4098                                                 expression->base.source_position, true_type,
4099                                                 false_type);
4100                 }
4101                 result_type = type_error_type;
4102         }
4103
4104         conditional->base.type = result_type;
4105         return result;
4106 }
4107
4108 /**
4109  * Parse an extension expression.
4110  */
4111 static expression_t *parse_extension(unsigned precedence)
4112 {
4113         eat(T___extension__);
4114
4115         /* TODO enable extensions */
4116         expression_t *expression = parse_sub_expression(precedence);
4117         /* TODO disable extensions */
4118         return expression;
4119 }
4120
4121 static expression_t *parse_builtin_classify_type(const unsigned precedence)
4122 {
4123         eat(T___builtin_classify_type);
4124
4125         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
4126         result->base.type    = type_int;
4127
4128         expect('(');
4129         expression_t *expression = parse_sub_expression(precedence);
4130         expect(')');
4131         result->classify_type.type_expression = expression;
4132
4133         return result;
4134 }
4135
4136 static void semantic_incdec(unary_expression_t *expression)
4137 {
4138         type_t *const orig_type = expression->value->base.type;
4139         type_t *const type      = skip_typeref(orig_type);
4140         /* TODO !is_type_real && !is_type_pointer */
4141         if(!is_type_arithmetic(type) && type->kind != TYPE_POINTER) {
4142                 if (is_type_valid(type)) {
4143                         /* TODO: improve error message */
4144                         errorf(HERE, "operation needs an arithmetic or pointer type");
4145                 }
4146                 return;
4147         }
4148
4149         expression->base.type = orig_type;
4150 }
4151
4152 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
4153 {
4154         type_t *const orig_type = expression->value->base.type;
4155         type_t *const type      = skip_typeref(orig_type);
4156         if(!is_type_arithmetic(type)) {
4157                 if (is_type_valid(type)) {
4158                         /* TODO: improve error message */
4159                         errorf(HERE, "operation needs an arithmetic type");
4160                 }
4161                 return;
4162         }
4163
4164         expression->base.type = orig_type;
4165 }
4166
4167 static void semantic_unexpr_scalar(unary_expression_t *expression)
4168 {
4169         type_t *const orig_type = expression->value->base.type;
4170         type_t *const type      = skip_typeref(orig_type);
4171         if (!is_type_scalar(type)) {
4172                 if (is_type_valid(type)) {
4173                         errorf(HERE, "operand of ! must be of scalar type");
4174                 }
4175                 return;
4176         }
4177
4178         expression->base.type = orig_type;
4179 }
4180
4181 static void semantic_unexpr_integer(unary_expression_t *expression)
4182 {
4183         type_t *const orig_type = expression->value->base.type;
4184         type_t *const type      = skip_typeref(orig_type);
4185         if (!is_type_integer(type)) {
4186                 if (is_type_valid(type)) {
4187                         errorf(HERE, "operand of ~ must be of integer type");
4188                 }
4189                 return;
4190         }
4191
4192         expression->base.type = orig_type;
4193 }
4194
4195 static void semantic_dereference(unary_expression_t *expression)
4196 {
4197         type_t *const orig_type = expression->value->base.type;
4198         type_t *const type      = skip_typeref(orig_type);
4199         if(!is_type_pointer(type)) {
4200                 if (is_type_valid(type)) {
4201                         errorf(HERE, "Unary '*' needs pointer or arrray type, but type '%T' given", orig_type);
4202                 }
4203                 return;
4204         }
4205
4206         type_t *result_type   = type->pointer.points_to;
4207         result_type           = automatic_type_conversion(result_type);
4208         expression->base.type = result_type;
4209 }
4210
4211 /**
4212  * Check the semantic of the address taken expression.
4213  */
4214 static void semantic_take_addr(unary_expression_t *expression)
4215 {
4216         expression_t *value = expression->value;
4217         value->base.type    = revert_automatic_type_conversion(value);
4218
4219         type_t *orig_type = value->base.type;
4220         if(!is_type_valid(orig_type))
4221                 return;
4222
4223         if(value->kind == EXPR_REFERENCE) {
4224                 declaration_t *const declaration = value->reference.declaration;
4225                 if(declaration != NULL) {
4226                         if (declaration->storage_class == STORAGE_CLASS_REGISTER) {
4227                                 errorf(expression->base.source_position,
4228                                         "address of register variable '%Y' requested",
4229                                         declaration->symbol);
4230                         }
4231                         declaration->address_taken = 1;
4232                 }
4233         }
4234
4235         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
4236 }
4237
4238 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc)   \
4239 static expression_t *parse_##unexpression_type(unsigned precedence)            \
4240 {                                                                              \
4241         eat(token_type);                                                           \
4242                                                                                    \
4243         expression_t *unary_expression                                             \
4244                 = allocate_expression_zero(unexpression_type);                         \
4245         unary_expression->base.source_position = HERE;                             \
4246         unary_expression->unary.value = parse_sub_expression(precedence);          \
4247                                                                                    \
4248         sfunc(&unary_expression->unary);                                           \
4249                                                                                    \
4250         return unary_expression;                                                   \
4251 }
4252
4253 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
4254                                semantic_unexpr_arithmetic)
4255 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
4256                                semantic_unexpr_arithmetic)
4257 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
4258                                semantic_unexpr_scalar)
4259 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
4260                                semantic_dereference)
4261 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
4262                                semantic_take_addr)
4263 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
4264                                semantic_unexpr_integer)
4265 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
4266                                semantic_incdec)
4267 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
4268                                semantic_incdec)
4269
4270 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
4271                                                sfunc)                         \
4272 static expression_t *parse_##unexpression_type(unsigned precedence,           \
4273                                                expression_t *left)            \
4274 {                                                                             \
4275         (void) precedence;                                                        \
4276         eat(token_type);                                                          \
4277                                                                               \
4278         expression_t *unary_expression                                            \
4279                 = allocate_expression_zero(unexpression_type);                        \
4280         unary_expression->unary.value = left;                                     \
4281                                                                                   \
4282         sfunc(&unary_expression->unary);                                          \
4283                                                                               \
4284         return unary_expression;                                                  \
4285 }
4286
4287 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
4288                                        EXPR_UNARY_POSTFIX_INCREMENT,
4289                                        semantic_incdec)
4290 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
4291                                        EXPR_UNARY_POSTFIX_DECREMENT,
4292                                        semantic_incdec)
4293
4294 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
4295 {
4296         /* TODO: handle complex + imaginary types */
4297
4298         /* § 6.3.1.8 Usual arithmetic conversions */
4299         if(type_left == type_long_double || type_right == type_long_double) {
4300                 return type_long_double;
4301         } else if(type_left == type_double || type_right == type_double) {
4302                 return type_double;
4303         } else if(type_left == type_float || type_right == type_float) {
4304                 return type_float;
4305         }
4306
4307         type_right = promote_integer(type_right);
4308         type_left  = promote_integer(type_left);
4309
4310         if(type_left == type_right)
4311                 return type_left;
4312
4313         bool signed_left  = is_type_signed(type_left);
4314         bool signed_right = is_type_signed(type_right);
4315         int  rank_left    = get_rank(type_left);
4316         int  rank_right   = get_rank(type_right);
4317         if(rank_left < rank_right) {
4318                 if(signed_left == signed_right || !signed_right) {
4319                         return type_right;
4320                 } else {
4321                         return type_left;
4322                 }
4323         } else {
4324                 if(signed_left == signed_right || !signed_left) {
4325                         return type_left;
4326                 } else {
4327                         return type_right;
4328                 }
4329         }
4330 }
4331
4332 /**
4333  * Check the semantic restrictions for a binary expression.
4334  */
4335 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
4336 {
4337         expression_t *const left            = expression->left;
4338         expression_t *const right           = expression->right;
4339         type_t       *const orig_type_left  = left->base.type;
4340         type_t       *const orig_type_right = right->base.type;
4341         type_t       *const type_left       = skip_typeref(orig_type_left);
4342         type_t       *const type_right      = skip_typeref(orig_type_right);
4343
4344         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4345                 /* TODO: improve error message */
4346                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4347                         errorf(HERE, "operation needs arithmetic types");
4348                 }
4349                 return;
4350         }
4351
4352         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4353         expression->left      = create_implicit_cast(left, arithmetic_type);
4354         expression->right     = create_implicit_cast(right, arithmetic_type);
4355         expression->base.type = arithmetic_type;
4356 }
4357
4358 static void semantic_shift_op(binary_expression_t *expression)
4359 {
4360         expression_t *const left            = expression->left;
4361         expression_t *const right           = expression->right;
4362         type_t       *const orig_type_left  = left->base.type;
4363         type_t       *const orig_type_right = right->base.type;
4364         type_t       *      type_left       = skip_typeref(orig_type_left);
4365         type_t       *      type_right      = skip_typeref(orig_type_right);
4366
4367         if(!is_type_integer(type_left) || !is_type_integer(type_right)) {
4368                 /* TODO: improve error message */
4369                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4370                         errorf(HERE, "operation needs integer types");
4371                 }
4372                 return;
4373         }
4374
4375         type_left  = promote_integer(type_left);
4376         type_right = promote_integer(type_right);
4377
4378         expression->left      = create_implicit_cast(left, type_left);
4379         expression->right     = create_implicit_cast(right, type_right);
4380         expression->base.type = type_left;
4381 }
4382
4383 static void semantic_add(binary_expression_t *expression)
4384 {
4385         expression_t *const left            = expression->left;
4386         expression_t *const right           = expression->right;
4387         type_t       *const orig_type_left  = left->base.type;
4388         type_t       *const orig_type_right = right->base.type;
4389         type_t       *const type_left       = skip_typeref(orig_type_left);
4390         type_t       *const type_right      = skip_typeref(orig_type_right);
4391
4392         /* § 5.6.5 */
4393         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4394                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4395                 expression->left  = create_implicit_cast(left, arithmetic_type);
4396                 expression->right = create_implicit_cast(right, arithmetic_type);
4397                 expression->base.type = arithmetic_type;
4398                 return;
4399         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4400                 expression->base.type = type_left;
4401         } else if(is_type_pointer(type_right) && is_type_integer(type_left)) {
4402                 expression->base.type = type_right;
4403         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4404                 errorf(HERE, "invalid operands to binary + ('%T', '%T')", orig_type_left, orig_type_right);
4405         }
4406 }
4407
4408 static void semantic_sub(binary_expression_t *expression)
4409 {
4410         expression_t *const left            = expression->left;
4411         expression_t *const right           = expression->right;
4412         type_t       *const orig_type_left  = left->base.type;
4413         type_t       *const orig_type_right = right->base.type;
4414         type_t       *const type_left       = skip_typeref(orig_type_left);
4415         type_t       *const type_right      = skip_typeref(orig_type_right);
4416
4417         /* § 5.6.5 */
4418         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4419                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4420                 expression->left        = create_implicit_cast(left, arithmetic_type);
4421                 expression->right       = create_implicit_cast(right, arithmetic_type);
4422                 expression->base.type =  arithmetic_type;
4423                 return;
4424         } else if(is_type_pointer(type_left) && is_type_integer(type_right)) {
4425                 expression->base.type = type_left;
4426         } else if(is_type_pointer(type_left) && is_type_pointer(type_right)) {
4427                 if(!pointers_compatible(type_left, type_right)) {
4428                         errorf(HERE,
4429                                "pointers to incompatible objects to binary '-' ('%T', '%T')",
4430                                orig_type_left, orig_type_right);
4431                 } else {
4432                         expression->base.type = type_ptrdiff_t;
4433                 }
4434         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4435                 errorf(HERE, "invalid operands to binary '-' ('%T', '%T')",
4436                        orig_type_left, orig_type_right);
4437         }
4438 }
4439
4440 /**
4441  * Check the semantics of comparison expressions.
4442  *
4443  * @param expression   The expression to check.
4444  */
4445 static void semantic_comparison(binary_expression_t *expression)
4446 {
4447         expression_t *left            = expression->left;
4448         expression_t *right           = expression->right;
4449         type_t       *orig_type_left  = left->base.type;
4450         type_t       *orig_type_right = right->base.type;
4451
4452         type_t *type_left  = skip_typeref(orig_type_left);
4453         type_t *type_right = skip_typeref(orig_type_right);
4454
4455         /* TODO non-arithmetic types */
4456         if(is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4457                 if (warning.sign_compare &&
4458                     (expression->base.kind != EXPR_BINARY_EQUAL &&
4459                      expression->base.kind != EXPR_BINARY_NOTEQUAL) &&
4460                     (is_type_signed(type_left) != is_type_signed(type_right))) {
4461                         warningf(expression->base.source_position,
4462                                  "comparison between signed and unsigned");
4463                 }
4464                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4465                 expression->left        = create_implicit_cast(left, arithmetic_type);
4466                 expression->right       = create_implicit_cast(right, arithmetic_type);
4467                 expression->base.type   = arithmetic_type;
4468                 if (warning.float_equal &&
4469                     (expression->base.kind == EXPR_BINARY_EQUAL ||
4470                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
4471                     is_type_float(arithmetic_type)) {
4472                         warningf(expression->base.source_position,
4473                                  "comparing floating point with == or != is unsafe");
4474                 }
4475         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
4476                 /* TODO check compatibility */
4477         } else if (is_type_pointer(type_left)) {
4478                 expression->right = create_implicit_cast(right, type_left);
4479         } else if (is_type_pointer(type_right)) {
4480                 expression->left = create_implicit_cast(left, type_right);
4481         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4482                 type_error_incompatible("invalid operands in comparison",
4483                                         expression->base.source_position,
4484                                         type_left, type_right);
4485         }
4486         expression->base.type = type_int;
4487 }
4488
4489 static void semantic_arithmetic_assign(binary_expression_t *expression)
4490 {
4491         expression_t *left            = expression->left;
4492         expression_t *right           = expression->right;
4493         type_t       *orig_type_left  = left->base.type;
4494         type_t       *orig_type_right = right->base.type;
4495
4496         type_t *type_left  = skip_typeref(orig_type_left);
4497         type_t *type_right = skip_typeref(orig_type_right);
4498
4499         if(!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
4500                 /* TODO: improve error message */
4501                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4502                         errorf(HERE, "operation needs arithmetic types");
4503                 }
4504                 return;
4505         }
4506
4507         /* combined instructions are tricky. We can't create an implicit cast on
4508          * the left side, because we need the uncasted form for the store.
4509          * The ast2firm pass has to know that left_type must be right_type
4510          * for the arithmetic operation and create a cast by itself */
4511         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
4512         expression->right       = create_implicit_cast(right, arithmetic_type);
4513         expression->base.type   = type_left;
4514 }
4515
4516 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
4517 {
4518         expression_t *const left            = expression->left;
4519         expression_t *const right           = expression->right;
4520         type_t       *const orig_type_left  = left->base.type;
4521         type_t       *const orig_type_right = right->base.type;
4522         type_t       *const type_left       = skip_typeref(orig_type_left);
4523         type_t       *const type_right      = skip_typeref(orig_type_right);
4524
4525         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
4526                 /* combined instructions are tricky. We can't create an implicit cast on
4527                  * the left side, because we need the uncasted form for the store.
4528                  * The ast2firm pass has to know that left_type must be right_type
4529                  * for the arithmetic operation and create a cast by itself */
4530                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
4531                 expression->right     = create_implicit_cast(right, arithmetic_type);
4532                 expression->base.type = type_left;
4533         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
4534                 expression->base.type = type_left;
4535         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
4536                 errorf(HERE, "incompatible types '%T' and '%T' in assignment", orig_type_left, orig_type_right);
4537         }
4538 }
4539
4540 /**
4541  * Check the semantic restrictions of a logical expression.
4542  */
4543 static void semantic_logical_op(binary_expression_t *expression)
4544 {
4545         expression_t *const left            = expression->left;
4546         expression_t *const right           = expression->right;
4547         type_t       *const orig_type_left  = left->base.type;
4548         type_t       *const orig_type_right = right->base.type;
4549         type_t       *const type_left       = skip_typeref(orig_type_left);
4550         type_t       *const type_right      = skip_typeref(orig_type_right);
4551
4552         if (!is_type_scalar(type_left) || !is_type_scalar(type_right)) {
4553                 /* TODO: improve error message */
4554                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
4555                         errorf(HERE, "operation needs scalar types");
4556                 }
4557                 return;
4558         }
4559
4560         expression->base.type = type_int;
4561 }
4562
4563 /**
4564  * Checks if a compound type has constant fields.
4565  */
4566 static bool has_const_fields(const compound_type_t *type)
4567 {
4568         const scope_t       *scope       = &type->declaration->scope;
4569         const declaration_t *declaration = scope->declarations;
4570
4571         for (; declaration != NULL; declaration = declaration->next) {
4572                 if (declaration->namespc != NAMESPACE_NORMAL)
4573                         continue;
4574
4575                 const type_t *decl_type = skip_typeref(declaration->type);
4576                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
4577                         return true;
4578         }
4579         /* TODO */
4580         return false;
4581 }
4582
4583 /**
4584  * Check the semantic restrictions of a binary assign expression.
4585  */
4586 static void semantic_binexpr_assign(binary_expression_t *expression)
4587 {
4588         expression_t *left           = expression->left;
4589         type_t       *orig_type_left = left->base.type;
4590
4591         type_t *type_left = revert_automatic_type_conversion(left);
4592         type_left         = skip_typeref(orig_type_left);
4593
4594         /* must be a modifiable lvalue */
4595         if (is_type_array(type_left)) {
4596                 errorf(HERE, "cannot assign to arrays ('%E')", left);
4597                 return;
4598         }
4599         if(type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
4600                 errorf(HERE, "assignment to readonly location '%E' (type '%T')", left,
4601                        orig_type_left);
4602                 return;
4603         }
4604         if(is_type_incomplete(type_left)) {
4605                 errorf(HERE,
4606                        "left-hand side of assignment '%E' has incomplete type '%T'",
4607                        left, orig_type_left);
4608                 return;
4609         }
4610         if(is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
4611                 errorf(HERE, "cannot assign to '%E' because compound type '%T' has readonly fields",
4612                        left, orig_type_left);
4613                 return;
4614         }
4615
4616         type_t *const res_type = semantic_assign(orig_type_left, expression->right,
4617                                                  "assignment");
4618         if (res_type == NULL) {
4619                 errorf(expression->base.source_position,
4620                         "cannot assign to '%T' from '%T'",
4621                         orig_type_left, expression->right->base.type);
4622         } else {
4623                 expression->right = create_implicit_cast(expression->right, res_type);
4624         }
4625
4626         expression->base.type = orig_type_left;
4627 }
4628
4629 static bool expression_has_effect(const expression_t *const expr)
4630 {
4631         switch (expr->kind) {
4632                 case EXPR_UNKNOWN:                   break;
4633                 case EXPR_INVALID:                   break;
4634                 case EXPR_REFERENCE:                 return false;
4635                 case EXPR_CONST:                     return false;
4636                 case EXPR_STRING_LITERAL:            return false;
4637                 case EXPR_WIDE_STRING_LITERAL:       return false;
4638                 case EXPR_CALL: {
4639                         const call_expression_t *const call = &expr->call;
4640                         if (call->function->kind != EXPR_BUILTIN_SYMBOL)
4641                                 return true;
4642
4643                         switch (call->function->builtin_symbol.symbol->ID) {
4644                                 case T___builtin_va_end: return true;
4645                                 default:                 return false;
4646                         }
4647                 }
4648                 case EXPR_CONDITIONAL: {
4649                         const conditional_expression_t *const cond = &expr->conditional;
4650                         return
4651                                 expression_has_effect(cond->true_expression) &&
4652                                 expression_has_effect(cond->false_expression);
4653                 }
4654                 case EXPR_SELECT:                    return false;
4655                 case EXPR_ARRAY_ACCESS:              return false;
4656                 case EXPR_SIZEOF:                    return false;
4657                 case EXPR_CLASSIFY_TYPE:             return false;
4658                 case EXPR_ALIGNOF:                   return false;
4659
4660                 case EXPR_FUNCTION:                  return false;
4661                 case EXPR_PRETTY_FUNCTION:           return false;
4662                 case EXPR_BUILTIN_SYMBOL:            break; /* handled in EXPR_CALL */
4663                 case EXPR_BUILTIN_CONSTANT_P:        return false;
4664                 case EXPR_BUILTIN_PREFETCH:          return true;
4665                 case EXPR_OFFSETOF:                  return false;
4666                 case EXPR_VA_START:                  return true;
4667                 case EXPR_VA_ARG:                    return true;
4668                 case EXPR_STATEMENT:                 return true; // TODO
4669
4670                 case EXPR_UNARY_NEGATE:              return false;
4671                 case EXPR_UNARY_PLUS:                return false;
4672                 case EXPR_UNARY_BITWISE_NEGATE:      return false;
4673                 case EXPR_UNARY_NOT:                 return false;
4674                 case EXPR_UNARY_DEREFERENCE:         return false;
4675                 case EXPR_UNARY_TAKE_ADDRESS:        return false;
4676                 case EXPR_UNARY_POSTFIX_INCREMENT:   return true;
4677                 case EXPR_UNARY_POSTFIX_DECREMENT:   return true;
4678                 case EXPR_UNARY_PREFIX_INCREMENT:    return true;
4679                 case EXPR_UNARY_PREFIX_DECREMENT:    return true;
4680                 case EXPR_UNARY_CAST:
4681                         return is_type_atomic(expr->base.type, ATOMIC_TYPE_VOID);
4682                 case EXPR_UNARY_CAST_IMPLICIT:       return true;
4683                 case EXPR_UNARY_ASSUME:              return true;
4684                 case EXPR_UNARY_BITFIELD_EXTRACT:    return false;
4685
4686                 case EXPR_BINARY_ADD:                return false;
4687                 case EXPR_BINARY_SUB:                return false;
4688                 case EXPR_BINARY_MUL:                return false;
4689                 case EXPR_BINARY_DIV:                return false;
4690                 case EXPR_BINARY_MOD:                return false;
4691                 case EXPR_BINARY_EQUAL:              return false;
4692                 case EXPR_BINARY_NOTEQUAL:           return false;
4693                 case EXPR_BINARY_LESS:               return false;
4694                 case EXPR_BINARY_LESSEQUAL:          return false;
4695                 case EXPR_BINARY_GREATER:            return false;
4696                 case EXPR_BINARY_GREATEREQUAL:       return false;
4697                 case EXPR_BINARY_BITWISE_AND:        return false;
4698                 case EXPR_BINARY_BITWISE_OR:         return false;
4699                 case EXPR_BINARY_BITWISE_XOR:        return false;
4700                 case EXPR_BINARY_SHIFTLEFT:          return false;
4701                 case EXPR_BINARY_SHIFTRIGHT:         return false;
4702                 case EXPR_BINARY_ASSIGN:             return true;
4703                 case EXPR_BINARY_MUL_ASSIGN:         return true;
4704                 case EXPR_BINARY_DIV_ASSIGN:         return true;
4705                 case EXPR_BINARY_MOD_ASSIGN:         return true;
4706                 case EXPR_BINARY_ADD_ASSIGN:         return true;
4707                 case EXPR_BINARY_SUB_ASSIGN:         return true;
4708                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:   return true;
4709                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:  return true;
4710                 case EXPR_BINARY_BITWISE_AND_ASSIGN: return true;
4711                 case EXPR_BINARY_BITWISE_XOR_ASSIGN: return true;
4712                 case EXPR_BINARY_BITWISE_OR_ASSIGN:  return true;
4713                 case EXPR_BINARY_LOGICAL_AND:
4714                 case EXPR_BINARY_LOGICAL_OR:
4715                 case EXPR_BINARY_COMMA:
4716                         return expression_has_effect(expr->binary.right);
4717
4718                 case EXPR_BINARY_BUILTIN_EXPECT:     return true;
4719                 case EXPR_BINARY_ISGREATER:          return false;
4720                 case EXPR_BINARY_ISGREATEREQUAL:     return false;
4721                 case EXPR_BINARY_ISLESS:             return false;
4722                 case EXPR_BINARY_ISLESSEQUAL:        return false;
4723                 case EXPR_BINARY_ISLESSGREATER:      return false;
4724                 case EXPR_BINARY_ISUNORDERED:        return false;
4725         }
4726
4727         panic("unexpected statement");
4728 }
4729
4730 static void semantic_comma(binary_expression_t *expression)
4731 {
4732         if (warning.unused_value) {
4733                 const expression_t *const left = expression->left;
4734                 if (!expression_has_effect(left)) {
4735                         warningf(left->base.source_position, "left-hand operand of comma expression has no effect");
4736                 }
4737         }
4738         expression->base.type = expression->right->base.type;
4739 }
4740
4741 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, sfunc, lr)  \
4742 static expression_t *parse_##binexpression_type(unsigned precedence,      \
4743                                                 expression_t *left)       \
4744 {                                                                         \
4745         eat(token_type);                                                      \
4746         source_position_t pos = HERE;                                         \
4747                                                                           \
4748         expression_t *right = parse_sub_expression(precedence + lr);          \
4749                                                                           \
4750         expression_t *binexpr = allocate_expression_zero(binexpression_type); \
4751         binexpr->base.source_position = pos;                                  \
4752         binexpr->binary.left  = left;                                         \
4753         binexpr->binary.right = right;                                        \
4754         sfunc(&binexpr->binary);                                              \
4755                                                                           \
4756         return binexpr;                                                       \
4757 }
4758
4759 CREATE_BINEXPR_PARSER(',', EXPR_BINARY_COMMA,    semantic_comma, 1)
4760 CREATE_BINEXPR_PARSER('*', EXPR_BINARY_MUL,      semantic_binexpr_arithmetic, 1)
4761 CREATE_BINEXPR_PARSER('/', EXPR_BINARY_DIV,      semantic_binexpr_arithmetic, 1)
4762 CREATE_BINEXPR_PARSER('%', EXPR_BINARY_MOD,      semantic_binexpr_arithmetic, 1)
4763 CREATE_BINEXPR_PARSER('+', EXPR_BINARY_ADD,      semantic_add, 1)
4764 CREATE_BINEXPR_PARSER('-', EXPR_BINARY_SUB,      semantic_sub, 1)
4765 CREATE_BINEXPR_PARSER('<', EXPR_BINARY_LESS,     semantic_comparison, 1)
4766 CREATE_BINEXPR_PARSER('>', EXPR_BINARY_GREATER,  semantic_comparison, 1)
4767 CREATE_BINEXPR_PARSER('=', EXPR_BINARY_ASSIGN,   semantic_binexpr_assign, 0)
4768
4769 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,
4770                       semantic_comparison, 1)
4771 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,
4772                       semantic_comparison, 1)
4773 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,
4774                       semantic_comparison, 1)
4775 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,
4776                       semantic_comparison, 1)
4777
4778 CREATE_BINEXPR_PARSER('&', EXPR_BINARY_BITWISE_AND,
4779                       semantic_binexpr_arithmetic, 1)
4780 CREATE_BINEXPR_PARSER('|', EXPR_BINARY_BITWISE_OR,
4781                       semantic_binexpr_arithmetic, 1)
4782 CREATE_BINEXPR_PARSER('^', EXPR_BINARY_BITWISE_XOR,
4783                       semantic_binexpr_arithmetic, 1)
4784 CREATE_BINEXPR_PARSER(T_ANDAND, EXPR_BINARY_LOGICAL_AND,
4785                       semantic_logical_op, 1)
4786 CREATE_BINEXPR_PARSER(T_PIPEPIPE, EXPR_BINARY_LOGICAL_OR,
4787                       semantic_logical_op, 1)
4788 CREATE_BINEXPR_PARSER(T_LESSLESS, EXPR_BINARY_SHIFTLEFT,
4789                       semantic_shift_op, 1)
4790 CREATE_BINEXPR_PARSER(T_GREATERGREATER, EXPR_BINARY_SHIFTRIGHT,
4791                       semantic_shift_op, 1)
4792 CREATE_BINEXPR_PARSER(T_PLUSEQUAL, EXPR_BINARY_ADD_ASSIGN,
4793                       semantic_arithmetic_addsubb_assign, 0)
4794 CREATE_BINEXPR_PARSER(T_MINUSEQUAL, EXPR_BINARY_SUB_ASSIGN,
4795                       semantic_arithmetic_addsubb_assign, 0)
4796 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL, EXPR_BINARY_MUL_ASSIGN,
4797                       semantic_arithmetic_assign, 0)
4798 CREATE_BINEXPR_PARSER(T_SLASHEQUAL, EXPR_BINARY_DIV_ASSIGN,
4799                       semantic_arithmetic_assign, 0)
4800 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL, EXPR_BINARY_MOD_ASSIGN,
4801                       semantic_arithmetic_assign, 0)
4802 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL, EXPR_BINARY_SHIFTLEFT_ASSIGN,
4803                       semantic_arithmetic_assign, 0)
4804 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL, EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4805                       semantic_arithmetic_assign, 0)
4806 CREATE_BINEXPR_PARSER(T_ANDEQUAL, EXPR_BINARY_BITWISE_AND_ASSIGN,
4807                       semantic_arithmetic_assign, 0)
4808 CREATE_BINEXPR_PARSER(T_PIPEEQUAL, EXPR_BINARY_BITWISE_OR_ASSIGN,
4809                       semantic_arithmetic_assign, 0)
4810 CREATE_BINEXPR_PARSER(T_CARETEQUAL, EXPR_BINARY_BITWISE_XOR_ASSIGN,
4811                       semantic_arithmetic_assign, 0)
4812
4813 static expression_t *parse_sub_expression(unsigned precedence)
4814 {
4815         if(token.type < 0) {
4816                 return expected_expression_error();
4817         }
4818
4819         expression_parser_function_t *parser
4820                 = &expression_parsers[token.type];
4821         source_position_t             source_position = token.source_position;
4822         expression_t                 *left;
4823
4824         if(parser->parser != NULL) {
4825                 left = parser->parser(parser->precedence);
4826         } else {
4827                 left = parse_primary_expression();
4828         }
4829         assert(left != NULL);
4830         left->base.source_position = source_position;
4831
4832         while(true) {
4833                 if(token.type < 0) {
4834                         return expected_expression_error();
4835                 }
4836
4837                 parser = &expression_parsers[token.type];
4838                 if(parser->infix_parser == NULL)
4839                         break;
4840                 if(parser->infix_precedence < precedence)
4841                         break;
4842
4843                 left = parser->infix_parser(parser->infix_precedence, left);
4844
4845                 assert(left != NULL);
4846                 assert(left->kind != EXPR_UNKNOWN);
4847                 left->base.source_position = source_position;
4848         }
4849
4850         return left;
4851 }
4852
4853 /**
4854  * Parse an expression.
4855  */
4856 static expression_t *parse_expression(void)
4857 {
4858         return parse_sub_expression(1);
4859 }
4860
4861 /**
4862  * Register a parser for a prefix-like operator with given precedence.
4863  *
4864  * @param parser      the parser function
4865  * @param token_type  the token type of the prefix token
4866  * @param precedence  the precedence of the operator
4867  */
4868 static void register_expression_parser(parse_expression_function parser,
4869                                        int token_type, unsigned precedence)
4870 {
4871         expression_parser_function_t *entry = &expression_parsers[token_type];
4872
4873         if(entry->parser != NULL) {
4874                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
4875                 panic("trying to register multiple expression parsers for a token");
4876         }
4877         entry->parser     = parser;
4878         entry->precedence = precedence;
4879 }
4880
4881 /**
4882  * Register a parser for an infix operator with given precedence.
4883  *
4884  * @param parser      the parser function
4885  * @param token_type  the token type of the infix operator
4886  * @param precedence  the precedence of the operator
4887  */
4888 static void register_infix_parser(parse_expression_infix_function parser,
4889                 int token_type, unsigned precedence)
4890 {
4891         expression_parser_function_t *entry = &expression_parsers[token_type];
4892
4893         if(entry->infix_parser != NULL) {
4894                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
4895                 panic("trying to register multiple infix expression parsers for a "
4896                       "token");
4897         }
4898         entry->infix_parser     = parser;
4899         entry->infix_precedence = precedence;
4900 }
4901
4902 /**
4903  * Initialize the expression parsers.
4904  */
4905 static void init_expression_parsers(void)
4906 {
4907         memset(&expression_parsers, 0, sizeof(expression_parsers));
4908
4909         register_infix_parser(parse_array_expression,         '[',              30);
4910         register_infix_parser(parse_call_expression,          '(',              30);
4911         register_infix_parser(parse_select_expression,        '.',              30);
4912         register_infix_parser(parse_select_expression,        T_MINUSGREATER,   30);
4913         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,
4914                                                               T_PLUSPLUS,       30);
4915         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,
4916                                                               T_MINUSMINUS,     30);
4917
4918         register_infix_parser(parse_EXPR_BINARY_MUL,          '*',              16);
4919         register_infix_parser(parse_EXPR_BINARY_DIV,          '/',              16);
4920         register_infix_parser(parse_EXPR_BINARY_MOD,          '%',              16);
4921         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,    T_LESSLESS,       16);
4922         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,   T_GREATERGREATER, 16);
4923         register_infix_parser(parse_EXPR_BINARY_ADD,          '+',              15);
4924         register_infix_parser(parse_EXPR_BINARY_SUB,          '-',              15);
4925         register_infix_parser(parse_EXPR_BINARY_LESS,         '<',              14);
4926         register_infix_parser(parse_EXPR_BINARY_GREATER,      '>',              14);
4927         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,    T_LESSEQUAL,      14);
4928         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL, T_GREATEREQUAL,   14);
4929         register_infix_parser(parse_EXPR_BINARY_EQUAL,        T_EQUALEQUAL,     13);
4930         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,
4931                                                     T_EXCLAMATIONMARKEQUAL, 13);
4932         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,  '&',              12);
4933         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,  '^',              11);
4934         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,   '|',              10);
4935         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,  T_ANDAND,          9);
4936         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,   T_PIPEPIPE,        8);
4937         register_infix_parser(parse_conditional_expression,   '?',               7);
4938         register_infix_parser(parse_EXPR_BINARY_ASSIGN,       '=',               2);
4939         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,   T_PLUSEQUAL,       2);
4940         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,   T_MINUSEQUAL,      2);
4941         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,   T_ASTERISKEQUAL,   2);
4942         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,   T_SLASHEQUAL,      2);
4943         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,   T_PERCENTEQUAL,    2);
4944         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,
4945                                                                 T_LESSLESSEQUAL, 2);
4946         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,
4947                                                           T_GREATERGREATEREQUAL, 2);
4948         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN,
4949                                                                      T_ANDEQUAL, 2);
4950         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,
4951                                                                     T_PIPEEQUAL, 2);
4952         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN,
4953                                                                    T_CARETEQUAL, 2);
4954
4955         register_infix_parser(parse_EXPR_BINARY_COMMA,        ',',               1);
4956
4957         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-',      25);
4958         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+',      25);
4959         register_expression_parser(parse_EXPR_UNARY_NOT,              '!',      25);
4960         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~',      25);
4961         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*',      25);
4962         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&',      25);
4963         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT,
4964                                                                   T_PLUSPLUS,   25);
4965         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT,
4966                                                                   T_MINUSMINUS, 25);
4967         register_expression_parser(parse_sizeof,                      T_sizeof, 25);
4968         register_expression_parser(parse_alignof,                T___alignof__, 25);
4969         register_expression_parser(parse_extension,            T___extension__, 25);
4970         register_expression_parser(parse_builtin_classify_type,
4971                                                      T___builtin_classify_type, 25);
4972 }
4973
4974 /**
4975  * Parse a asm statement constraints specification.
4976  */
4977 static asm_constraint_t *parse_asm_constraints(void)
4978 {
4979         asm_constraint_t *result = NULL;
4980         asm_constraint_t *last   = NULL;
4981
4982         while(token.type == T_STRING_LITERAL || token.type == '[') {
4983                 asm_constraint_t *constraint = allocate_ast_zero(sizeof(constraint[0]));
4984                 memset(constraint, 0, sizeof(constraint[0]));
4985
4986                 if(token.type == '[') {
4987                         eat('[');
4988                         if(token.type != T_IDENTIFIER) {
4989                                 parse_error_expected("while parsing asm constraint",
4990                                                      T_IDENTIFIER, 0);
4991                                 return NULL;
4992                         }
4993                         constraint->symbol = token.v.symbol;
4994
4995                         expect(']');
4996                 }
4997
4998                 constraint->constraints = parse_string_literals();
4999                 expect('(');
5000                 constraint->expression = parse_expression();
5001                 expect(')');
5002
5003                 if(last != NULL) {
5004                         last->next = constraint;
5005                 } else {
5006                         result = constraint;
5007                 }
5008                 last = constraint;
5009
5010                 if(token.type != ',')
5011                         break;
5012                 eat(',');
5013         }
5014
5015         return result;
5016 }
5017
5018 /**
5019  * Parse a asm statement clobber specification.
5020  */
5021 static asm_clobber_t *parse_asm_clobbers(void)
5022 {
5023         asm_clobber_t *result = NULL;
5024         asm_clobber_t *last   = NULL;
5025
5026         while(token.type == T_STRING_LITERAL) {
5027                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
5028                 clobber->clobber       = parse_string_literals();
5029
5030                 if(last != NULL) {
5031                         last->next = clobber;
5032                 } else {
5033                         result = clobber;
5034                 }
5035                 last = clobber;
5036
5037                 if(token.type != ',')
5038                         break;
5039                 eat(',');
5040         }
5041
5042         return result;
5043 }
5044
5045 /**
5046  * Parse an asm statement.
5047  */
5048 static statement_t *parse_asm_statement(void)
5049 {
5050         eat(T_asm);
5051
5052         statement_t *statement          = allocate_statement_zero(STATEMENT_ASM);
5053         statement->base.source_position = token.source_position;
5054
5055         asm_statement_t *asm_statement = &statement->asms;
5056
5057         if(token.type == T_volatile) {
5058                 next_token();
5059                 asm_statement->is_volatile = true;
5060         }
5061
5062         expect('(');
5063         asm_statement->asm_text = parse_string_literals();
5064
5065         if(token.type != ':')
5066                 goto end_of_asm;
5067         eat(':');
5068
5069         asm_statement->inputs = parse_asm_constraints();
5070         if(token.type != ':')
5071                 goto end_of_asm;
5072         eat(':');
5073
5074         asm_statement->outputs = parse_asm_constraints();
5075         if(token.type != ':')
5076                 goto end_of_asm;
5077         eat(':');
5078
5079         asm_statement->clobbers = parse_asm_clobbers();
5080
5081 end_of_asm:
5082         expect(')');
5083         expect(';');
5084         return statement;
5085 }
5086
5087 /**
5088  * Parse a case statement.
5089  */
5090 static statement_t *parse_case_statement(void)
5091 {
5092         eat(T_case);
5093
5094         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
5095
5096         statement->base.source_position  = token.source_position;
5097         statement->case_label.expression = parse_expression();
5098
5099         expect(':');
5100
5101         if (! is_constant_expression(statement->case_label.expression)) {
5102                 errorf(statement->base.source_position,
5103                         "case label does not reduce to an integer constant");
5104         } else {
5105                 /* TODO: check if the case label is already known */
5106                 if (current_switch != NULL) {
5107                         /* link all cases into the switch statement */
5108                         if (current_switch->last_case == NULL) {
5109                                 current_switch->first_case =
5110                                 current_switch->last_case  = &statement->case_label;
5111                         } else {
5112                                 current_switch->last_case->next = &statement->case_label;
5113                         }
5114                 } else {
5115                         errorf(statement->base.source_position,
5116                                 "case label not within a switch statement");
5117                 }
5118         }
5119         statement->case_label.statement = parse_statement();
5120
5121         return statement;
5122 }
5123
5124 /**
5125  * Finds an existing default label of a switch statement.
5126  */
5127 static case_label_statement_t *
5128 find_default_label(const switch_statement_t *statement)
5129 {
5130         for (case_label_statement_t *label = statement->first_case;
5131              label != NULL;
5132                  label = label->next) {
5133                 if (label->expression == NULL)
5134                         return label;
5135         }
5136         return NULL;
5137 }
5138
5139 /**
5140  * Parse a default statement.
5141  */
5142 static statement_t *parse_default_statement(void)
5143 {
5144         eat(T_default);
5145
5146         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
5147
5148         statement->base.source_position = token.source_position;
5149
5150         expect(':');
5151         if (current_switch != NULL) {
5152                 const case_label_statement_t *def_label = find_default_label(current_switch);
5153                 if (def_label != NULL) {
5154                         errorf(HERE, "multiple default labels in one switch");
5155                         errorf(def_label->base.source_position,
5156                                 "this is the first default label");
5157                 } else {
5158                         /* link all cases into the switch statement */
5159                         if (current_switch->last_case == NULL) {
5160                                 current_switch->first_case =
5161                                         current_switch->last_case  = &statement->case_label;
5162                         } else {
5163                                 current_switch->last_case->next = &statement->case_label;
5164                         }
5165                 }
5166         } else {
5167                 errorf(statement->base.source_position,
5168                         "'default' label not within a switch statement");
5169         }
5170         statement->label.statement = parse_statement();
5171
5172         return statement;
5173 }
5174
5175 /**
5176  * Return the declaration for a given label symbol or create a new one.
5177  */
5178 static declaration_t *get_label(symbol_t *symbol)
5179 {
5180         declaration_t *candidate = get_declaration(symbol, NAMESPACE_LABEL);
5181         assert(current_function != NULL);
5182         /* if we found a label in the same function, then we already created the
5183          * declaration */
5184         if(candidate != NULL
5185                         && candidate->parent_scope == &current_function->scope) {
5186                 return candidate;
5187         }
5188
5189         /* otherwise we need to create a new one */
5190         declaration_t *const declaration = allocate_declaration_zero();
5191         declaration->namespc       = NAMESPACE_LABEL;
5192         declaration->symbol        = symbol;
5193
5194         label_push(declaration);
5195
5196         return declaration;
5197 }
5198
5199 /**
5200  * Parse a label statement.
5201  */
5202 static statement_t *parse_label_statement(void)
5203 {
5204         assert(token.type == T_IDENTIFIER);
5205         symbol_t *symbol = token.v.symbol;
5206         next_token();
5207
5208         declaration_t *label = get_label(symbol);
5209
5210         /* if source position is already set then the label is defined twice,
5211          * otherwise it was just mentioned in a goto so far */
5212         if(label->source_position.input_name != NULL) {
5213                 errorf(HERE, "duplicate label '%Y'", symbol);
5214                 errorf(label->source_position, "previous definition of '%Y' was here",
5215                        symbol);
5216         } else {
5217                 label->source_position = token.source_position;
5218         }
5219
5220         statement_t *statement = allocate_statement_zero(STATEMENT_LABEL);
5221
5222         statement->base.source_position = token.source_position;
5223         statement->label.label          = label;
5224
5225         eat(':');
5226
5227         if(token.type == '}') {
5228                 /* TODO only warn? */
5229                 errorf(HERE, "label at end of compound statement");
5230                 return statement;
5231         } else {
5232                 if (token.type == ';') {
5233                         /* eat an empty statement here, to avoid the warning about an empty
5234                          * after a label.  label:; is commonly used to have a label before
5235                          * a }. */
5236                         next_token();
5237                 } else {
5238                         statement->label.statement = parse_statement();
5239                 }
5240         }
5241
5242         /* remember the labels's in a list for later checking */
5243         if (label_last == NULL) {
5244                 label_first = &statement->label;
5245         } else {
5246                 label_last->next = &statement->label;
5247         }
5248         label_last = &statement->label;
5249
5250         return statement;
5251 }
5252
5253 /**
5254  * Parse an if statement.
5255  */
5256 static statement_t *parse_if(void)
5257 {
5258         eat(T_if);
5259
5260         statement_t *statement          = allocate_statement_zero(STATEMENT_IF);
5261         statement->base.source_position = token.source_position;
5262
5263         expect('(');
5264         statement->ifs.condition = parse_expression();
5265         expect(')');
5266
5267         statement->ifs.true_statement = parse_statement();
5268         if(token.type == T_else) {
5269                 next_token();
5270                 statement->ifs.false_statement = parse_statement();
5271         }
5272
5273         return statement;
5274 }
5275
5276 /**
5277  * Parse a switch statement.
5278  */
5279 static statement_t *parse_switch(void)
5280 {
5281         eat(T_switch);
5282
5283         statement_t *statement          = allocate_statement_zero(STATEMENT_SWITCH);
5284         statement->base.source_position = token.source_position;
5285
5286         expect('(');
5287         expression_t *const expr = parse_expression();
5288         type_t       *      type = skip_typeref(expr->base.type);
5289         if (is_type_integer(type)) {
5290                 type = promote_integer(type);
5291         } else if (is_type_valid(type)) {
5292                 errorf(expr->base.source_position,
5293                        "switch quantity is not an integer, but '%T'", type);
5294                 type = type_error_type;
5295         }
5296         statement->switchs.expression = create_implicit_cast(expr, type);
5297         expect(')');
5298
5299         switch_statement_t *rem = current_switch;
5300         current_switch          = &statement->switchs;
5301         statement->switchs.body = parse_statement();
5302         current_switch          = rem;
5303
5304         if (warning.switch_default
5305                         && find_default_label(&statement->switchs) == NULL) {
5306                 warningf(statement->base.source_position, "switch has no default case");
5307         }
5308
5309         return statement;
5310 }
5311
5312 static statement_t *parse_loop_body(statement_t *const loop)
5313 {
5314         statement_t *const rem = current_loop;
5315         current_loop = loop;
5316
5317         statement_t *const body = parse_statement();
5318
5319         current_loop = rem;
5320         return body;
5321 }
5322
5323 /**
5324  * Parse a while statement.
5325  */
5326 static statement_t *parse_while(void)
5327 {
5328         eat(T_while);
5329
5330         statement_t *statement          = allocate_statement_zero(STATEMENT_WHILE);
5331         statement->base.source_position = token.source_position;
5332
5333         expect('(');
5334         statement->whiles.condition = parse_expression();
5335         expect(')');
5336
5337         statement->whiles.body = parse_loop_body(statement);
5338
5339         return statement;
5340 }
5341
5342 /**
5343  * Parse a do statement.
5344  */
5345 static statement_t *parse_do(void)
5346 {
5347         eat(T_do);
5348
5349         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
5350
5351         statement->base.source_position = token.source_position;
5352
5353         statement->do_while.body = parse_loop_body(statement);
5354
5355         expect(T_while);
5356         expect('(');
5357         statement->do_while.condition = parse_expression();
5358         expect(')');
5359         expect(';');
5360
5361         return statement;
5362 }
5363
5364 /**
5365  * Parse a for statement.
5366  */
5367 static statement_t *parse_for(void)
5368 {
5369         eat(T_for);
5370
5371         statement_t *statement          = allocate_statement_zero(STATEMENT_FOR);
5372         statement->base.source_position = token.source_position;
5373
5374         expect('(');
5375
5376         int      top        = environment_top();
5377         scope_t *last_scope = scope;
5378         set_scope(&statement->fors.scope);
5379
5380         if(token.type != ';') {
5381                 if(is_declaration_specifier(&token, false)) {
5382                         parse_declaration(record_declaration);
5383                 } else {
5384                         statement->fors.initialisation = parse_expression();
5385                         expect(';');
5386                 }
5387         } else {
5388                 expect(';');
5389         }
5390
5391         if(token.type != ';') {
5392                 statement->fors.condition = parse_expression();
5393         }
5394         expect(';');
5395         if(token.type != ')') {
5396                 statement->fors.step = parse_expression();
5397         }
5398         expect(')');
5399         statement->fors.body = parse_loop_body(statement);
5400
5401         assert(scope == &statement->fors.scope);
5402         set_scope(last_scope);
5403         environment_pop_to(top);
5404
5405         return statement;
5406 }
5407
5408 /**
5409  * Parse a goto statement.
5410  */
5411 static statement_t *parse_goto(void)
5412 {
5413         eat(T_goto);
5414
5415         if(token.type != T_IDENTIFIER) {
5416                 parse_error_expected("while parsing goto", T_IDENTIFIER, 0);
5417                 eat_statement();
5418                 return NULL;
5419         }
5420         symbol_t *symbol = token.v.symbol;
5421         next_token();
5422
5423         declaration_t *label = get_label(symbol);
5424
5425         statement_t *statement          = allocate_statement_zero(STATEMENT_GOTO);
5426         statement->base.source_position = token.source_position;
5427
5428         statement->gotos.label = label;
5429
5430         /* remember the goto's in a list for later checking */
5431         if (goto_last == NULL) {
5432                 goto_first = &statement->gotos;
5433         } else {
5434                 goto_last->next = &statement->gotos;
5435         }
5436         goto_last = &statement->gotos;
5437
5438         expect(';');
5439
5440         return statement;
5441 }
5442
5443 /**
5444  * Parse a continue statement.
5445  */
5446 static statement_t *parse_continue(void)
5447 {
5448         statement_t *statement;
5449         if (current_loop == NULL) {
5450                 errorf(HERE, "continue statement not within loop");
5451                 statement = NULL;
5452         } else {
5453                 statement = allocate_statement_zero(STATEMENT_CONTINUE);
5454
5455                 statement->base.source_position = token.source_position;
5456         }
5457
5458         eat(T_continue);
5459         expect(';');
5460
5461         return statement;
5462 }
5463
5464 /**
5465  * Parse a break statement.
5466  */
5467 static statement_t *parse_break(void)
5468 {
5469         statement_t *statement;
5470         if (current_switch == NULL && current_loop == NULL) {
5471                 errorf(HERE, "break statement not within loop or switch");
5472                 statement = NULL;
5473         } else {
5474                 statement = allocate_statement_zero(STATEMENT_BREAK);
5475
5476                 statement->base.source_position = token.source_position;
5477         }
5478
5479         eat(T_break);
5480         expect(';');
5481
5482         return statement;
5483 }
5484
5485 /**
5486  * Check if a given declaration represents a local variable.
5487  */
5488 static bool is_local_var_declaration(const declaration_t *declaration) {
5489         switch ((storage_class_tag_t) declaration->storage_class) {
5490         case STORAGE_CLASS_NONE:
5491         case STORAGE_CLASS_AUTO:
5492         case STORAGE_CLASS_REGISTER: {
5493                 const type_t *type = skip_typeref(declaration->type);
5494                 if(is_type_function(type)) {
5495                         return false;
5496                 } else {
5497                         return true;
5498                 }
5499         }
5500         default:
5501                 return false;
5502         }
5503 }
5504
5505 /**
5506  * Check if a given declaration represents a variable.
5507  */
5508 static bool is_var_declaration(const declaration_t *declaration) {
5509         switch ((storage_class_tag_t) declaration->storage_class) {
5510         case STORAGE_CLASS_NONE:
5511         case STORAGE_CLASS_EXTERN:
5512         case STORAGE_CLASS_STATIC:
5513         case STORAGE_CLASS_AUTO:
5514         case STORAGE_CLASS_REGISTER:
5515         case STORAGE_CLASS_THREAD:
5516         case STORAGE_CLASS_THREAD_EXTERN:
5517         case STORAGE_CLASS_THREAD_STATIC: {
5518                 const type_t *type = skip_typeref(declaration->type);
5519                 if(is_type_function(type)) {
5520                         return false;
5521                 } else {
5522                         return true;
5523                 }
5524         }
5525         default:
5526                 return false;
5527         }
5528 }
5529
5530 /**
5531  * Check if a given expression represents a local variable.
5532  */
5533 static bool is_local_variable(const expression_t *expression)
5534 {
5535         if (expression->base.kind != EXPR_REFERENCE) {
5536                 return false;
5537         }
5538         const declaration_t *declaration = expression->reference.declaration;
5539         return is_local_var_declaration(declaration);
5540 }
5541
5542 /**
5543  * Check if a given expression represents a local variable and
5544  * return its declaration then, else return NULL.
5545  */
5546 declaration_t *expr_is_variable(const expression_t *expression)
5547 {
5548         if (expression->base.kind != EXPR_REFERENCE) {
5549                 return NULL;
5550         }
5551         declaration_t *declaration = expression->reference.declaration;
5552         if (is_var_declaration(declaration))
5553                 return declaration;
5554         return NULL;
5555 }
5556
5557 /**
5558  * Parse a return statement.
5559  */
5560 static statement_t *parse_return(void)
5561 {
5562         eat(T_return);
5563
5564         statement_t *statement          = allocate_statement_zero(STATEMENT_RETURN);
5565         statement->base.source_position = token.source_position;
5566
5567         expression_t *return_value = NULL;
5568         if(token.type != ';') {
5569                 return_value = parse_expression();
5570         }
5571         expect(';');
5572
5573         const type_t *const func_type = current_function->type;
5574         assert(is_type_function(func_type));
5575         type_t *const return_type = skip_typeref(func_type->function.return_type);
5576
5577         if(return_value != NULL) {
5578                 type_t *return_value_type = skip_typeref(return_value->base.type);
5579
5580                 if(is_type_atomic(return_type, ATOMIC_TYPE_VOID)
5581                                 && !is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
5582                         warningf(statement->base.source_position,
5583                                  "'return' with a value, in function returning void");
5584                         return_value = NULL;
5585                 } else {
5586                         type_t *const res_type = semantic_assign(return_type,
5587                                 return_value, "'return'");
5588                         if (res_type == NULL) {
5589                                 errorf(statement->base.source_position,
5590                                        "cannot return something of type '%T' in function returning '%T'",
5591                                        return_value->base.type, return_type);
5592                         } else {
5593                                 return_value = create_implicit_cast(return_value, res_type);
5594                         }
5595                 }
5596                 /* check for returning address of a local var */
5597                 if (return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
5598                         const expression_t *expression = return_value->unary.value;
5599                         if (is_local_variable(expression)) {
5600                                 warningf(statement->base.source_position,
5601                                          "function returns address of local variable");
5602                         }
5603                 }
5604         } else {
5605                 if(!is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
5606                         warningf(statement->base.source_position,
5607                                  "'return' without value, in function returning non-void");
5608                 }
5609         }
5610         statement->returns.value = return_value;
5611
5612         return statement;
5613 }
5614
5615 /**
5616  * Parse a declaration statement.
5617  */
5618 static statement_t *parse_declaration_statement(void)
5619 {
5620         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
5621
5622         statement->base.source_position = token.source_position;
5623
5624         declaration_t *before = last_declaration;
5625         parse_declaration(record_declaration);
5626
5627         if(before == NULL) {
5628                 statement->declaration.declarations_begin = scope->declarations;
5629         } else {
5630                 statement->declaration.declarations_begin = before->next;
5631         }
5632         statement->declaration.declarations_end = last_declaration;
5633
5634         return statement;
5635 }
5636
5637 /**
5638  * Parse an expression statement, ie. expr ';'.
5639  */
5640 static statement_t *parse_expression_statement(void)
5641 {
5642         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
5643
5644         statement->base.source_position  = token.source_position;
5645         expression_t *const expr         = parse_expression();
5646         statement->expression.expression = expr;
5647
5648         if (warning.unused_value  && !expression_has_effect(expr)) {
5649                 warningf(expr->base.source_position, "statement has no effect");
5650         }
5651
5652         expect(';');
5653
5654         return statement;
5655 }
5656
5657 /**
5658  * Parse a statement.
5659  */
5660 static statement_t *parse_statement(void)
5661 {
5662         statement_t   *statement = NULL;
5663
5664         /* declaration or statement */
5665         switch(token.type) {
5666         case T_asm:
5667                 statement = parse_asm_statement();
5668                 break;
5669
5670         case T_case:
5671                 statement = parse_case_statement();
5672                 break;
5673
5674         case T_default:
5675                 statement = parse_default_statement();
5676                 break;
5677
5678         case '{':
5679                 statement = parse_compound_statement();
5680                 break;
5681
5682         case T_if:
5683                 statement = parse_if();
5684                 break;
5685
5686         case T_switch:
5687                 statement = parse_switch();
5688                 break;
5689
5690         case T_while:
5691                 statement = parse_while();
5692                 break;
5693
5694         case T_do:
5695                 statement = parse_do();
5696                 break;
5697
5698         case T_for:
5699                 statement = parse_for();
5700                 break;
5701
5702         case T_goto:
5703                 statement = parse_goto();
5704                 break;
5705
5706         case T_continue:
5707                 statement = parse_continue();
5708                 break;
5709
5710         case T_break:
5711                 statement = parse_break();
5712                 break;
5713
5714         case T_return:
5715                 statement = parse_return();
5716                 break;
5717
5718         case ';':
5719                 if (warning.empty_statement) {
5720                         warningf(HERE, "statement is empty");
5721                 }
5722                 next_token();
5723                 statement = NULL;
5724                 break;
5725
5726         case T_IDENTIFIER:
5727                 if(look_ahead(1)->type == ':') {
5728                         statement = parse_label_statement();
5729                         break;
5730                 }
5731
5732                 if(is_typedef_symbol(token.v.symbol)) {
5733                         statement = parse_declaration_statement();
5734                         break;
5735                 }
5736
5737                 statement = parse_expression_statement();
5738                 break;
5739
5740         case T___extension__:
5741                 /* this can be a prefix to a declaration or an expression statement */
5742                 /* we simply eat it now and parse the rest with tail recursion */
5743                 do {
5744                         next_token();
5745                 } while(token.type == T___extension__);
5746                 statement = parse_statement();
5747                 break;
5748
5749         DECLARATION_START
5750                 statement = parse_declaration_statement();
5751                 break;
5752
5753         default:
5754                 statement = parse_expression_statement();
5755                 break;
5756         }
5757
5758         assert(statement == NULL
5759                         || statement->base.source_position.input_name != NULL);
5760
5761         return statement;
5762 }
5763
5764 /**
5765  * Parse a compound statement.
5766  */
5767 static statement_t *parse_compound_statement(void)
5768 {
5769         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
5770
5771         statement->base.source_position = token.source_position;
5772
5773         eat('{');
5774
5775         int      top        = environment_top();
5776         scope_t *last_scope = scope;
5777         set_scope(&statement->compound.scope);
5778
5779         statement_t *last_statement = NULL;
5780
5781         while(token.type != '}' && token.type != T_EOF) {
5782                 statement_t *sub_statement = parse_statement();
5783                 if(sub_statement == NULL)
5784                         continue;
5785
5786                 if(last_statement != NULL) {
5787                         last_statement->base.next = sub_statement;
5788                 } else {
5789                         statement->compound.statements = sub_statement;
5790                 }
5791
5792                 while(sub_statement->base.next != NULL)
5793                         sub_statement = sub_statement->base.next;
5794
5795                 last_statement = sub_statement;
5796         }
5797
5798         if(token.type == '}') {
5799                 next_token();
5800         } else {
5801                 errorf(statement->base.source_position,
5802                        "end of file while looking for closing '}'");
5803         }
5804
5805         assert(scope == &statement->compound.scope);
5806         set_scope(last_scope);
5807         environment_pop_to(top);
5808
5809         return statement;
5810 }
5811
5812 /**
5813  * Initialize builtin types.
5814  */
5815 static void initialize_builtin_types(void)
5816 {
5817         type_intmax_t    = make_global_typedef("__intmax_t__",      type_long_long);
5818         type_size_t      = make_global_typedef("__SIZE_TYPE__",     type_unsigned_long);
5819         type_ssize_t     = make_global_typedef("__SSIZE_TYPE__",    type_long);
5820         type_ptrdiff_t   = make_global_typedef("__PTRDIFF_TYPE__",  type_long);
5821         type_uintmax_t   = make_global_typedef("__uintmax_t__",     type_unsigned_long_long);
5822         type_uptrdiff_t  = make_global_typedef("__UPTRDIFF_TYPE__", type_unsigned_long);
5823         type_wchar_t     = make_global_typedef("__WCHAR_TYPE__",    type_int);
5824         type_wint_t      = make_global_typedef("__WINT_TYPE__",     type_int);
5825
5826         type_intmax_t_ptr  = make_pointer_type(type_intmax_t,  TYPE_QUALIFIER_NONE);
5827         type_ptrdiff_t_ptr = make_pointer_type(type_ptrdiff_t, TYPE_QUALIFIER_NONE);
5828         type_ssize_t_ptr   = make_pointer_type(type_ssize_t,   TYPE_QUALIFIER_NONE);
5829         type_wchar_t_ptr   = make_pointer_type(type_wchar_t,   TYPE_QUALIFIER_NONE);
5830 }
5831
5832 /**
5833  * Check for unused global static functions and variables
5834  */
5835 static void check_unused_globals(void)
5836 {
5837         if (!warning.unused_function && !warning.unused_variable)
5838                 return;
5839
5840         for (const declaration_t *decl = global_scope->declarations; decl != NULL; decl = decl->next) {
5841                 if (decl->used || decl->storage_class != STORAGE_CLASS_STATIC)
5842                         continue;
5843
5844                 type_t *const type = decl->type;
5845                 const char *s;
5846                 if (is_type_function(skip_typeref(type))) {
5847                         if (!warning.unused_function || decl->is_inline)
5848                                 continue;
5849
5850                         s = (decl->init.statement != NULL ? "defined" : "declared");
5851                 } else {
5852                         if (!warning.unused_variable)
5853                                 continue;
5854
5855                         s = "defined";
5856                 }
5857
5858                 warningf(decl->source_position, "'%#T' %s but not used",
5859                         type, decl->symbol, s);
5860         }
5861 }
5862
5863 /**
5864  * Parse a translation unit.
5865  */
5866 static translation_unit_t *parse_translation_unit(void)
5867 {
5868         translation_unit_t *unit = allocate_ast_zero(sizeof(unit[0]));
5869
5870         assert(global_scope == NULL);
5871         global_scope = &unit->scope;
5872
5873         assert(scope == NULL);
5874         set_scope(&unit->scope);
5875
5876         initialize_builtin_types();
5877
5878         while(token.type != T_EOF) {
5879                 if (token.type == ';') {
5880                         /* TODO error in strict mode */
5881                         warningf(HERE, "stray ';' outside of function");
5882                         next_token();
5883                 } else {
5884                         parse_external_declaration();
5885                 }
5886         }
5887
5888         assert(scope == &unit->scope);
5889         scope          = NULL;
5890         last_declaration = NULL;
5891
5892         assert(global_scope == &unit->scope);
5893         check_unused_globals();
5894         global_scope = NULL;
5895
5896         return unit;
5897 }
5898
5899 /**
5900  * Parse the input.
5901  *
5902  * @return  the translation unit or NULL if errors occurred.
5903  */
5904 translation_unit_t *parse(void)
5905 {
5906         environment_stack = NEW_ARR_F(stack_entry_t, 0);
5907         label_stack       = NEW_ARR_F(stack_entry_t, 0);
5908         diagnostic_count  = 0;
5909         error_count       = 0;
5910         warning_count     = 0;
5911
5912         type_set_output(stderr);
5913         ast_set_output(stderr);
5914
5915         lookahead_bufpos = 0;
5916         for(int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
5917                 next_token();
5918         }
5919         translation_unit_t *unit = parse_translation_unit();
5920
5921         DEL_ARR_F(environment_stack);
5922         DEL_ARR_F(label_stack);
5923
5924         if(error_count > 0)
5925                 return NULL;
5926
5927         return unit;
5928 }
5929
5930 /**
5931  * Initialize the parser.
5932  */
5933 void init_parser(void)
5934 {
5935         init_expression_parsers();
5936         obstack_init(&temp_obst);
5937
5938         symbol_t *const va_list_sym = symbol_table_insert("__builtin_va_list");
5939         type_valist = create_builtin_type(va_list_sym, type_void_ptr);
5940 }
5941
5942 /**
5943  * Terminate the parser.
5944  */
5945 void exit_parser(void)
5946 {
5947         obstack_free(&temp_obst, NULL);
5948 }