nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2012 Matthias Braun <matze@braunis.de>
   4  */
   5 #include <config.h>
   6
   7 #include <assert.h>
   8 #include <ctype.h>
   9 #include <stdarg.h>
  10 #include <stdbool.h>
  11
  12 #include "adt/strutil.h"
  13 #include "parser.h"
  14 #include "diagnostic.h"
  15 #include "format_check.h"
  16 #include "preprocessor.h"
  17 #include "symbol_t.h"
  18 #include "token_t.h"
  19 #include "types.h"
  20 #include "type_t.h"
  21 #include "type_hash.h"
  22 #include "ast_t.h"
  23 #include "entity_t.h"
  24 #include "attribute_t.h"
  25 #include "lang_features.h"
  26 #include "walk.h"
  27 #include "warning.h"
  28 #include "printer.h"
  29 #include "ast2firm.h"
  30 #include "adt/bitfiddle.h"
  31 #include "adt/error.h"
  32 #include "adt/array.h"
  33
  34 //#define PRINT_TOKENS
  35 #define MAX_LOOKAHEAD 1
  36
  37 typedef struct {
  38         entity_t           *old_entity;
  39         symbol_t           *symbol;
  40         entity_namespace_t  namespc;
  41 } stack_entry_t;
  42
  43 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  44 struct declaration_specifiers_t {
  45         position_t      pos;
  46         storage_class_t storage_class;
  47         unsigned char   alignment;         /**< Alignment, 0 if not set. */
  48         bool            is_inline    : 1;
  49         bool            thread_local : 1;
  50         attribute_t    *attributes;        /**< list of attributes */
  51         type_t         *type;
  52 };
  53
  54 /**
  55  * An environment for parsing initializers (and compound literals).
  56  */
  57 typedef struct parse_initializer_env_t {
  58         type_t     *type;   /**< the type of the initializer. In case of an
  59                                  array type with unspecified size this gets
  60                                  adjusted to the actual size. */
  61         entity_t   *entity; /**< the variable that is initialized if any */
  62         bool        must_be_constant;
  63 } parse_initializer_env_t;
  64
  65 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  66
  67 /** The current token. */
  68 static token_t              token;
  69 /** The lookahead ring-buffer. */
  70 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  71 /** Position of the next token in the lookahead buffer. */
  72 static size_t               lookahead_bufpos;
  73 static stack_entry_t       *environment_stack = NULL;
  74 static stack_entry_t       *label_stack       = NULL;
  75 static scope_t             *file_scope        = NULL;
  76 static scope_t             *current_scope     = NULL;
  77 /** Point to the current function declaration if inside a function. */
  78 static function_t          *current_function  = NULL;
  79 static entity_t            *current_entity    = NULL;
  80 static switch_statement_t  *current_switch    = NULL;
  81 static statement_t         *current_loop      = NULL;
  82 static statement_t         *current_parent    = NULL;
  83 static ms_try_statement_t  *current_try       = NULL;
  84 static linkage_kind_t       current_linkage;
  85 static goto_statement_t    *goto_first        = NULL;
  86 static goto_statement_t   **goto_anchor       = NULL;
  87 static label_statement_t   *label_first       = NULL;
  88 static label_statement_t  **label_anchor      = NULL;
  89 /** current translation unit. */
  90 static translation_unit_t  *unit              = NULL;
  91 /** true if we are in an __extension__ context. */
  92 static bool                 in_gcc_extension  = false;
  93 static struct obstack       temp_obst;
  94 static entity_t            *anonymous_entity;
  95 static declaration_t      **incomplete_arrays;
  96 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
  97
  98
  99 #define PUSH_CURRENT_ENTITY(entity) \
 100         entity_t *const new_current_entity = (entity); \
 101         entity_t *const old_current_entity = current_entity; \
 102         ((void)(current_entity = new_current_entity))
 103 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 104
 105 #define PUSH_PARENT(stmt) \
 106         statement_t *const new_parent = (stmt); \
 107         statement_t *const old_parent = current_parent; \
 108         ((void)(current_parent = new_parent))
 109 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 110
 111 #define PUSH_SCOPE(scope) \
 112         size_t   const top       = environment_top(); \
 113         scope_t *const new_scope = (scope); \
 114         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 115 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 116 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 117
 118 #define PUSH_EXTENSION() \
 119         (void)0; \
 120         bool const old_gcc_extension = in_gcc_extension; \
 121         while (accept(T___extension__)) { \
 122                 in_gcc_extension = true; \
 123         } \
 124         do {} while (0)
 125 #define POP_EXTENSION() \
 126         ((void)(in_gcc_extension = old_gcc_extension))
 127
 128 /** The token anchor set */
 129 static unsigned short token_anchor_set[T_LAST_TOKEN];
 130
 131 /** The current source position. */
 132 #define HERE (&token.base.pos)
 133
 134 /** true if we are in GCC mode. */
 135 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 136
 137 static statement_t *parse_compound_statement(bool inside_expression_statement);
 138 static statement_t *parse_statement(void);
 139
 140 static expression_t *parse_subexpression(precedence_t);
 141 static expression_t *parse_expression(void);
 142 static type_t       *parse_typename(void);
 143 static void          parse_externals(void);
 144 static void          parse_external(void);
 145
 146 static void parse_compound_type_entries(compound_t *compound_declaration);
 147
 148 static void check_call_argument(type_t          *expected_type,
 149                                                                 call_argument_t *argument, unsigned pos);
 150
 151 typedef enum declarator_flags_t {
 152         DECL_FLAGS_NONE             = 0,
 153         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 154         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 155         DECL_IS_PARAMETER           = 1U << 2
 156 } declarator_flags_t;
 157
 158 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 159                                   declarator_flags_t flags);
 160
 161 static void semantic_comparison(binary_expression_t *expression,
 162                                 bool is_relational);
 163
 164 #define STORAGE_CLASSES       \
 165         STORAGE_CLASSES_NO_EXTERN \
 166         case T_extern:
 167
 168 #define STORAGE_CLASSES_NO_EXTERN \
 169         case T_typedef:         \
 170         case T_static:          \
 171         case T_auto:            \
 172         case T_register:        \
 173         case T__Thread_local:
 174
 175 #define TYPE_QUALIFIERS     \
 176         case T_const:           \
 177         case T_restrict:        \
 178         case T_volatile:        \
 179         case T_inline:          \
 180         case T__forceinline:    \
 181         case T___attribute__:
 182
 183 #define COMPLEX_SPECIFIERS  \
 184         case T__Complex:
 185 #define IMAGINARY_SPECIFIERS \
 186         case T__Imaginary:
 187
 188 #define TYPE_SPECIFIERS       \
 189         case T__Bool:             \
 190         case T___builtin_va_list: \
 191         case T___typeof__:        \
 192         case T__declspec:         \
 193         case T_bool:              \
 194         case T_char:              \
 195         case T_double:            \
 196         case T_enum:              \
 197         case T_float:             \
 198         case T_int:               \
 199         case T_long:              \
 200         case T_short:             \
 201         case T_signed:            \
 202         case T_struct:            \
 203         case T_union:             \
 204         case T_unsigned:          \
 205         case T_void:              \
 206         case T_wchar_t:           \
 207         case T__int8:             \
 208         case T__int16:            \
 209         case T__int32:            \
 210         case T__int64:            \
 211         case T__int128:           \
 212         COMPLEX_SPECIFIERS        \
 213         IMAGINARY_SPECIFIERS
 214
 215 #define DECLARATION_START   \
 216         STORAGE_CLASSES         \
 217         TYPE_QUALIFIERS         \
 218         TYPE_SPECIFIERS
 219
 220 #define DECLARATION_START_NO_EXTERN \
 221         STORAGE_CLASSES_NO_EXTERN       \
 222         TYPE_QUALIFIERS                 \
 223         TYPE_SPECIFIERS
 224
 225 #define EXPRESSION_START              \
 226         case '!':                         \
 227         case '&':                         \
 228         case '(':                         \
 229         case '*':                         \
 230         case '+':                         \
 231         case '-':                         \
 232         case '~':                         \
 233         case T_ANDAND:                    \
 234         case T_CHARACTER_CONSTANT:        \
 235         case T_NUMBER:                    \
 236         case T_MINUSMINUS:                \
 237         case T_PLUSPLUS:                  \
 238         case T_STRING_LITERAL:            \
 239         case T__Alignof:                  \
 240         case T___FUNCDNAME__:             \
 241         case T___FUNCSIG__:               \
 242         case T___PRETTY_FUNCTION__:       \
 243         case T___builtin_classify_type:   \
 244         case T___builtin_constant_p:      \
 245         case T___builtin_isgreater:       \
 246         case T___builtin_isgreaterequal:  \
 247         case T___builtin_isless:          \
 248         case T___builtin_islessequal:     \
 249         case T___builtin_islessgreater:   \
 250         case T___builtin_isunordered:     \
 251         case T___builtin_offsetof:        \
 252         case T___builtin_va_arg:          \
 253         case T___builtin_va_copy:         \
 254         case T___builtin_va_start:        \
 255         case T___func__:                  \
 256         case T___noop:                    \
 257         case T__assume:                   \
 258         case T_delete:                    \
 259         case T_false:                     \
 260         case T_sizeof:                    \
 261         case T_throw:                     \
 262         case T_true:                      \
 263         case T___imag__:                  \
 264         case T___real__:
 265
 266 /**
 267  * Returns the size of a statement node.
 268  *
 269  * @param kind  the statement kind
 270  */
 271 static size_t get_statement_struct_size(statement_kind_t kind)
 272 {
 273         static const size_t sizes[] = {
 274                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 275                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 276                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 277                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 278                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 279                 [STATEMENT_IF]            = sizeof(if_statement_t),
 280                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 281                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 282                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 283                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 284                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 285                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 286                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 287                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 288                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 289                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 290                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 291                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 292                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 293         };
 294         assert((size_t)kind < lengthof(sizes));
 295         assert(sizes[kind] != 0);
 296         return sizes[kind];
 297 }
 298
 299 /**
 300  * Returns the size of an expression node.
 301  *
 302  * @param kind  the expression kind
 303  */
 304 static size_t get_expression_struct_size(expression_kind_t kind)
 305 {
 306         static const size_t sizes[] = {
 307                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 308                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 309                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 310                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 311                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 312                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 313                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 314                 [EXPR_LITERAL_MS_NOOP]            = sizeof(literal_expression_t),
 315                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 316                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 317                 [EXPR_CALL]                       = sizeof(call_expression_t),
 318                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 319                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 320                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 321                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 322                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 323                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 324                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 325                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 326                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 327                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 328                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 329                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 330                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 331                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 332                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 333                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 334                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 335         };
 336         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 337                 return sizes[EXPR_UNARY_FIRST];
 338         }
 339         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 340                 return sizes[EXPR_BINARY_FIRST];
 341         }
 342         assert((size_t)kind < lengthof(sizes));
 343         assert(sizes[kind] != 0);
 344         return sizes[kind];
 345 }
 346
 347 /**
 348  * Allocate a statement node of given kind and initialize all
 349  * fields with zero. Sets its source position to the position
 350  * of the current token.
 351  */
 352 static statement_t *allocate_statement_zero(statement_kind_t kind)
 353 {
 354         size_t       size = get_statement_struct_size(kind);
 355         statement_t *res  = allocate_ast_zero(size);
 356
 357         res->base.kind   = kind;
 358         res->base.parent = current_parent;
 359         res->base.pos    = *HERE;
 360         return res;
 361 }
 362
 363 /**
 364  * Allocate an expression node of given kind and initialize all
 365  * fields with zero.
 366  *
 367  * @param kind  the kind of the expression to allocate
 368  */
 369 static expression_t *allocate_expression_zero(expression_kind_t kind)
 370 {
 371         size_t        size = get_expression_struct_size(kind);
 372         expression_t *res  = allocate_ast_zero(size);
 373
 374         res->base.kind = kind;
 375         res->base.type = type_error_type;
 376         res->base.pos  = *HERE;
 377         return res;
 378 }
 379
 380 /**
 381  * Creates a new invalid expression at the source position
 382  * of the current token.
 383  */
 384 static expression_t *create_error_expression(void)
 385 {
 386         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 387         expression->base.type = type_error_type;
 388         return expression;
 389 }
 390
 391 /**
 392  * Creates a new invalid statement.
 393  */
 394 static statement_t *create_error_statement(void)
 395 {
 396         return allocate_statement_zero(STATEMENT_ERROR);
 397 }
 398
 399 /**
 400  * Allocate a new empty statement.
 401  */
 402 static statement_t *create_empty_statement(void)
 403 {
 404         return allocate_statement_zero(STATEMENT_EMPTY);
 405 }
 406
 407 /**
 408  * Returns the size of an initializer node.
 409  *
 410  * @param kind  the initializer kind
 411  */
 412 static size_t get_initializer_size(initializer_kind_t kind)
 413 {
 414         static const size_t sizes[] = {
 415                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 416                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 417                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 418                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 419         };
 420         assert((size_t)kind < lengthof(sizes));
 421         assert(sizes[kind] != 0);
 422         return sizes[kind];
 423 }
 424
 425 /**
 426  * Allocate an initializer node of given kind and initialize all
 427  * fields with zero.
 428  */
 429 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 430 {
 431         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 432         result->kind          = kind;
 433
 434         return result;
 435 }
 436
 437 /**
 438  * Returns the index of the top element of the environment stack.
 439  */
 440 static size_t environment_top(void)
 441 {
 442         return ARR_LEN(environment_stack);
 443 }
 444
 445 /**
 446  * Returns the index of the top element of the global label stack.
 447  */
 448 static size_t label_top(void)
 449 {
 450         return ARR_LEN(label_stack);
 451 }
 452
 453 /**
 454  * Return the next token.
 455  */
 456 static inline void next_token(void)
 457 {
 458         token                              = lookahead_buffer[lookahead_bufpos];
 459         lookahead_buffer[lookahead_bufpos] = pp_token;
 460         next_preprocessing_token();
 461
 462         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 463
 464 #ifdef PRINT_TOKENS
 465         print_token(stderr, &token);
 466         fprintf(stderr, "\n");
 467 #endif
 468 }
 469
 470 static inline void eat(token_kind_t const kind)
 471 {
 472         assert(token.kind == kind);
 473         (void)kind;
 474         next_token();
 475 }
 476
 477 /**
 478  * Consume the current token, if it is of the expected kind.
 479  *
 480  * @param  kind  The kind of token to consume.
 481  * @return Whether the token was consumed.
 482  */
 483 static inline bool accept(token_kind_t const kind)
 484 {
 485         if (token.kind == kind) {
 486                 eat(kind);
 487                 return true;
 488         } else {
 489                 return false;
 490         }
 491 }
 492
 493 /**
 494  * Return the next token with a given lookahead.
 495  */
 496 static inline const token_t *look_ahead(size_t num)
 497 {
 498         assert(0 < num && num <= MAX_LOOKAHEAD);
 499         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 500         return &lookahead_buffer[pos];
 501 }
 502
 503 /**
 504  * Adds a token type to the token type anchor set (a multi-set).
 505  */
 506 static void add_anchor_token(token_kind_t const token_kind)
 507 {
 508         assert(token_kind < T_LAST_TOKEN);
 509         ++token_anchor_set[token_kind];
 510 }
 511
 512 /**
 513  * Remove a token type from the token type anchor set (a multi-set).
 514  */
 515 static void rem_anchor_token(token_kind_t const token_kind)
 516 {
 517         assert(token_kind < T_LAST_TOKEN);
 518         assert(token_anchor_set[token_kind] != 0);
 519         --token_anchor_set[token_kind];
 520 }
 521
 522 /**
 523  * Eat tokens until a matching token type is found.
 524  */
 525 static void eat_until_matching_token(token_kind_t const type)
 526 {
 527         token_kind_t end_token;
 528         switch (type) {
 529                 case '(': end_token = ')';  break;
 530                 case '{': end_token = '}';  break;
 531                 case '[': end_token = ']';  break;
 532                 default:  end_token = type; break;
 533         }
 534
 535         unsigned parenthesis_count = 0;
 536         unsigned brace_count       = 0;
 537         unsigned bracket_count     = 0;
 538         while (token.kind        != end_token ||
 539                parenthesis_count != 0         ||
 540                brace_count       != 0         ||
 541                bracket_count     != 0) {
 542                 switch (token.kind) {
 543                 case T_EOF: return;
 544                 case '(': ++parenthesis_count; break;
 545                 case '{': ++brace_count;       break;
 546                 case '[': ++bracket_count;     break;
 547
 548                 case ')':
 549                         if (parenthesis_count > 0)
 550                                 --parenthesis_count;
 551                         goto check_stop;
 552
 553                 case '}':
 554                         if (brace_count > 0)
 555                                 --brace_count;
 556                         goto check_stop;
 557
 558                 case ']':
 559                         if (bracket_count > 0)
 560                                 --bracket_count;
 561 check_stop:
 562                         if (token.kind        == end_token &&
 563                             parenthesis_count == 0         &&
 564                             brace_count       == 0         &&
 565                             bracket_count     == 0)
 566                                 return;
 567                         break;
 568
 569                 default:
 570                         break;
 571                 }
 572                 next_token();
 573         }
 574 }
 575
 576 /**
 577  * Eat input tokens until an anchor is found.
 578  */
 579 static void eat_until_anchor(void)
 580 {
 581         while (token_anchor_set[token.kind] == 0) {
 582                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 583                         eat_until_matching_token(token.kind);
 584                 next_token();
 585         }
 586 }
 587
 588 /**
 589  * Eat a whole block from input tokens.
 590  */
 591 static void eat_block(void)
 592 {
 593         eat_until_matching_token('{');
 594         accept('}');
 595 }
 596
 597 /**
 598  * Report a parse error because an expected token was not found.
 599  */
 600 static
 601 #if defined __GNUC__ && __GNUC__ >= 4
 602 __attribute__((sentinel))
 603 #endif
 604 void parse_error_expected(const char *message, ...)
 605 {
 606         if (message != NULL) {
 607                 errorf(HERE, "%s", message);
 608         }
 609         va_list ap;
 610         va_start(ap, message);
 611         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 612         va_end(ap);
 613 }
 614
 615 /**
 616  * Report an incompatible type.
 617  */
 618 static void type_error_incompatible(const char *msg,
 619                 const position_t *pos, type_t *type1, type_t *type2)
 620 {
 621         errorf(pos, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 622 }
 623
 624 static bool skip_till(token_kind_t const expected, char const *const context)
 625 {
 626         if (UNLIKELY(token.kind != expected)) {
 627                 parse_error_expected(context, expected, NULL);
 628                 add_anchor_token(expected);
 629                 eat_until_anchor();
 630                 rem_anchor_token(expected);
 631                 if (token.kind != expected)
 632                         return false;
 633         }
 634         return true;
 635 }
 636
 637 /**
 638  * Expect the current token is the expected token.
 639  * If not, generate an error and skip until the next anchor.
 640  */
 641 static void expect(token_kind_t const expected)
 642 {
 643         if (skip_till(expected, NULL))
 644                 eat(expected);
 645 }
 646
 647 static symbol_t *expect_identifier(char const *const context,
 648                                    position_t *const pos)
 649 {
 650         if (!skip_till(T_IDENTIFIER, context))
 651                 return NULL;
 652         symbol_t *const sym = token.base.symbol;
 653         if (pos)
 654                 *pos = *HERE;
 655         eat(T_IDENTIFIER);
 656         return sym;
 657 }
 658
 659 /**
 660  * Push a given scope on the scope stack and make it the
 661  * current scope
 662  */
 663 static scope_t *scope_push(scope_t *new_scope)
 664 {
 665         if (current_scope != NULL) {
 666                 new_scope->depth = current_scope->depth + 1;
 667         }
 668
 669         scope_t *old_scope = current_scope;
 670         current_scope      = new_scope;
 671         return old_scope;
 672 }
 673
 674 /**
 675  * Pop the current scope from the scope stack.
 676  */
 677 static void scope_pop(scope_t *old_scope)
 678 {
 679         current_scope = old_scope;
 680 }
 681
 682 /**
 683  * Search an entity by its symbol in a given namespace.
 684  */
 685 static entity_t *get_entity(const symbol_t *const symbol,
 686                             namespace_tag_t namespc)
 687 {
 688         entity_t *entity = symbol->entity;
 689         for (; entity != NULL; entity = entity->base.symbol_next) {
 690                 if ((namespace_tag_t)entity->base.namespc == namespc)
 691                         return entity;
 692         }
 693
 694         return NULL;
 695 }
 696
 697 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 698  * possible. */
 699 static entity_t *get_tag(symbol_t const *const symbol,
 700                          entity_kind_tag_t const kind)
 701 {
 702         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 703         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 704                 errorf(HERE,
 705                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 706                                 symbol, &entity->base.pos);
 707                 entity = NULL;
 708         }
 709         return entity;
 710 }
 711
 712 /**
 713  * pushs an entity on the environment stack and links the corresponding symbol
 714  * it.
 715  */
 716 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 717 {
 718         symbol_t           *symbol  = entity->base.symbol;
 719         entity_namespace_t  namespc = entity->base.namespc;
 720         assert(namespc != 0);
 721
 722         /* replace/add entity into entity list of the symbol */
 723         entity_t **anchor;
 724         entity_t  *iter;
 725         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 726                 iter = *anchor;
 727                 if (iter == NULL)
 728                         break;
 729
 730                 /* replace an entry? */
 731                 if (iter->base.namespc == namespc) {
 732                         entity->base.symbol_next = iter->base.symbol_next;
 733                         break;
 734                 }
 735         }
 736         *anchor = entity;
 737
 738         /* remember old declaration */
 739         stack_entry_t entry;
 740         entry.symbol     = symbol;
 741         entry.old_entity = iter;
 742         entry.namespc    = namespc;
 743         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 744 }
 745
 746 /**
 747  * Push an entity on the environment stack.
 748  */
 749 static void environment_push(entity_t *entity)
 750 {
 751         assert(entity->base.pos.input_name != NULL);
 752         assert(entity->base.parent_scope != NULL);
 753         stack_push(&environment_stack, entity);
 754 }
 755
 756 /**
 757  * Push a declaration on the global label stack.
 758  *
 759  * @param declaration  the declaration
 760  */
 761 static void label_push(entity_t *label)
 762 {
 763         /* we abuse the parameters scope as parent for the labels */
 764         label->base.parent_scope = &current_function->parameters;
 765         stack_push(&label_stack, label);
 766 }
 767
 768 /**
 769  * pops symbols from the environment stack until @p new_top is the top element
 770  */
 771 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 772 {
 773         stack_entry_t *stack = *stack_ptr;
 774         size_t         top   = ARR_LEN(stack);
 775         size_t         i;
 776
 777         assert(new_top <= top);
 778         if (new_top == top)
 779                 return;
 780
 781         for (i = top; i > new_top; --i) {
 782                 stack_entry_t *entry = &stack[i - 1];
 783
 784                 entity_t           *old_entity = entry->old_entity;
 785                 symbol_t           *symbol     = entry->symbol;
 786                 entity_namespace_t  namespc    = entry->namespc;
 787
 788                 /* replace with old_entity/remove */
 789                 entity_t **anchor;
 790                 entity_t  *iter;
 791                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 792                         iter = *anchor;
 793                         assert(iter != NULL);
 794                         /* replace an entry? */
 795                         if (iter->base.namespc == namespc)
 796                                 break;
 797                 }
 798
 799                 /* restore definition from outer scopes (if there was one) */
 800                 if (old_entity != NULL) {
 801                         old_entity->base.symbol_next = iter->base.symbol_next;
 802                         *anchor                      = old_entity;
 803                 } else {
 804                         /* remove entry from list */
 805                         *anchor = iter->base.symbol_next;
 806                 }
 807         }
 808
 809         ARR_SHRINKLEN(*stack_ptr, new_top);
 810 }
 811
 812 /**
 813  * Pop all entries from the environment stack until the new_top
 814  * is reached.
 815  *
 816  * @param new_top  the new stack top
 817  */
 818 static void environment_pop_to(size_t new_top)
 819 {
 820         stack_pop_to(&environment_stack, new_top);
 821 }
 822
 823 /**
 824  * Pop all entries from the global label stack until the new_top
 825  * is reached.
 826  *
 827  * @param new_top  the new stack top
 828  */
 829 static void label_pop_to(size_t new_top)
 830 {
 831         stack_pop_to(&label_stack, new_top);
 832 }
 833
 834 /**
 835  * §6.3.1.1:2  Do integer promotion for a given type.
 836  *
 837  * @param type  the type to promote
 838  * @return the promoted type
 839  */
 840 static type_t *promote_integer(type_t *type)
 841 {
 842         atomic_type_kind_t akind = get_arithmetic_akind(type);
 843         if (get_akind_rank(akind) < get_akind_rank(ATOMIC_TYPE_INT))
 844                 type = type_int;
 845
 846         return type;
 847 }
 848
 849 /**
 850  * Check if a given expression represents a null pointer constant.
 851  *
 852  * @param expression  the expression to check
 853  */
 854 static bool is_null_pointer_constant(const expression_t *expression)
 855 {
 856         /* skip void* cast */
 857         if (expression->kind == EXPR_UNARY_CAST) {
 858                 type_t *const type = skip_typeref(expression->base.type);
 859                 if (types_compatible(type, type_void_ptr))
 860                         expression = expression->unary.value;
 861         }
 862
 863         type_t *const type = skip_typeref(expression->base.type);
 864         if (!is_type_integer(type))
 865                 return false;
 866         switch (is_constant_expression(expression)) {
 867                 case EXPR_CLASS_ERROR:    return true;
 868                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 869                 default:                  return false;
 870         }
 871 }
 872
 873 /**
 874  * Create an implicit cast expression.
 875  *
 876  * @param expression  the expression to cast
 877  * @param dest_type   the destination type
 878  */
 879 static expression_t *create_implicit_cast(expression_t *expression,
 880                                           type_t *dest_type)
 881 {
 882         type_t *const source_type = skip_typeref(expression->base.type);
 883         if (source_type == skip_typeref(dest_type))
 884                 return expression;
 885
 886         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 887         cast->unary.value   = expression;
 888         cast->base.type     = dest_type;
 889         cast->base.implicit = true;
 890
 891         return cast;
 892 }
 893
 894 typedef enum assign_error_t {
 895         ASSIGN_SUCCESS,
 896         ASSIGN_ERROR_INCOMPATIBLE,
 897         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 898         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 899         ASSIGN_WARNING_POINTER_FROM_INT,
 900         ASSIGN_WARNING_INT_FROM_POINTER
 901 } assign_error_t;
 902
 903 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, position_t const *const pos)
 904 {
 905         type_t *const orig_type_right = right->base.type;
 906         type_t *const type_left       = skip_typeref(orig_type_left);
 907         type_t *const type_right      = skip_typeref(orig_type_right);
 908
 909         switch (error) {
 910         case ASSIGN_SUCCESS:
 911                 return;
 912         case ASSIGN_ERROR_INCOMPATIBLE:
 913                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 914                 return;
 915
 916         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 917                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 918                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 919
 920                 /* the left type has all qualifiers from the right type */
 921                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 922                 warningf(WARN_OTHER, pos, "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type", orig_type_left, context, orig_type_right, missing_qualifiers);
 923                 return;
 924         }
 925
 926         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 927                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 928                 return;
 929
 930         case ASSIGN_WARNING_POINTER_FROM_INT:
 931                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 932                 return;
 933
 934         case ASSIGN_WARNING_INT_FROM_POINTER:
 935                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 936                 return;
 937
 938         default:
 939                 panic("invalid error value");
 940         }
 941 }
 942
 943 /** Implements the rules from §6.5.16.1 */
 944 static assign_error_t semantic_assign(type_t *orig_type_left,
 945                                       const expression_t *const right)
 946 {
 947         type_t *const orig_type_right = right->base.type;
 948         type_t *const type_left       = skip_typeref(orig_type_left);
 949         type_t *const type_right      = skip_typeref(orig_type_right);
 950
 951         if (is_type_pointer(type_left)) {
 952                 if (is_null_pointer_constant(right)) {
 953                         return ASSIGN_SUCCESS;
 954                 } else if (is_type_pointer(type_right)) {
 955                         type_t *points_to_left
 956                                 = skip_typeref(type_left->pointer.points_to);
 957                         type_t *points_to_right
 958                                 = skip_typeref(type_right->pointer.points_to);
 959                         assign_error_t res = ASSIGN_SUCCESS;
 960
 961                         /* the left type has all qualifiers from the right type */
 962                         unsigned missing_qualifiers
 963                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 964                         if (missing_qualifiers != 0) {
 965                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 966                         }
 967
 968                         points_to_left  = get_unqualified_type(points_to_left);
 969                         points_to_right = get_unqualified_type(points_to_right);
 970
 971                         if (is_type_void(points_to_left))
 972                                 return res;
 973
 974                         if (is_type_void(points_to_right)) {
 975                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 976                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 977                         }
 978
 979                         if (!types_compatible(points_to_left, points_to_right)) {
 980                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 981                         }
 982
 983                         return res;
 984                 } else if (is_type_integer(type_right)) {
 985                         return ASSIGN_WARNING_POINTER_FROM_INT;
 986                 }
 987         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
 988                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
 989                                 && is_type_pointer(type_right))) {
 990                 return ASSIGN_SUCCESS;
 991         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
 992                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
 993                 type_t *const unqual_type_right = get_unqualified_type(type_right);
 994                 if (types_compatible(unqual_type_left, unqual_type_right)) {
 995                         return ASSIGN_SUCCESS;
 996                 }
 997         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
 998                 return ASSIGN_WARNING_INT_FROM_POINTER;
 999         }
1000
1001         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1002                 return ASSIGN_SUCCESS;
1003
1004         return ASSIGN_ERROR_INCOMPATIBLE;
1005 }
1006
1007 static expression_t *parse_constant_expression(void)
1008 {
1009         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1010
1011         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1012                 errorf(&result->base.pos, "expression '%E' is not constant", result);
1013         }
1014
1015         return result;
1016 }
1017
1018 static expression_t *parse_assignment_expression(void)
1019 {
1020         return parse_subexpression(PREC_ASSIGNMENT);
1021 }
1022
1023 static void append_string(string_t const *const s)
1024 {
1025         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1026          * possible, because other tokens are grown there alongside. */
1027         obstack_grow(&ast_obstack, s->begin, s->size);
1028 }
1029
1030 static string_t finish_string(string_encoding_t const enc)
1031 {
1032         obstack_1grow(&ast_obstack, '\0');
1033         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1034         char const *const string = obstack_finish(&ast_obstack);
1035         return (string_t){ string, size, enc };
1036 }
1037
1038 static string_t concat_string_literals(void)
1039 {
1040         assert(token.kind == T_STRING_LITERAL);
1041
1042         string_t result;
1043         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1044                 append_string(&token.literal.string);
1045                 eat(T_STRING_LITERAL);
1046                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1047                 string_encoding_t enc = token.literal.string.encoding;
1048                 do {
1049                         string_encoding_t const new_enc = token.literal.string.encoding;
1050                         if (new_enc != enc && new_enc != STRING_ENCODING_CHAR) {
1051                                 if (enc == STRING_ENCODING_CHAR) {
1052                                         enc = new_enc;
1053                                 } else {
1054                                         errorf(HERE, "concatenating string literals with encodings %s and %s", get_string_encoding_prefix(enc), get_string_encoding_prefix(new_enc));
1055                                 }
1056                         }
1057                         append_string(&token.literal.string);
1058                         eat(T_STRING_LITERAL);
1059                 } while (token.kind == T_STRING_LITERAL);
1060                 result = finish_string(enc);
1061         } else {
1062                 result = token.literal.string;
1063                 eat(T_STRING_LITERAL);
1064         }
1065
1066         return result;
1067 }
1068
1069 static string_t parse_string_literals(char const *const context)
1070 {
1071         if (!skip_till(T_STRING_LITERAL, context))
1072                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1073
1074         position_t const pos = *HERE;
1075         string_t   const res = concat_string_literals();
1076
1077         if (res.encoding != STRING_ENCODING_CHAR) {
1078                 errorf(&pos, "expected plain string literal, got %s string literal", get_string_encoding_prefix(res.encoding));
1079         }
1080
1081         return res;
1082 }
1083
1084 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1085 {
1086         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1087         attribute->kind = kind;
1088         attribute->pos  = *HERE;
1089         return attribute;
1090 }
1091
1092 /**
1093  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1094  *
1095  *  attribute:
1096  *    __attribute__ ( ( attribute-list ) )
1097  *
1098  *  attribute-list:
1099  *    attrib
1100  *    attribute_list , attrib
1101  *
1102  *  attrib:
1103  *    empty
1104  *    any-word
1105  *    any-word ( identifier )
1106  *    any-word ( identifier , nonempty-expr-list )
1107  *    any-word ( expr-list )
1108  *
1109  *  where the "identifier" must not be declared as a type, and
1110  *  "any-word" may be any identifier (including one declared as a
1111  *  type), a reserved word storage class specifier, type specifier or
1112  *  type qualifier.  ??? This still leaves out most reserved keywords
1113  *  (following the old parser), shouldn't we include them, and why not
1114  *  allow identifiers declared as types to start the arguments?
1115  *
1116  *  Matze: this all looks confusing and little systematic, so we're even less
1117  *  strict and parse any list of things which are identifiers or
1118  *  (assignment-)expressions.
1119  */
1120 static attribute_argument_t *parse_attribute_arguments(void)
1121 {
1122         attribute_argument_t  *first  = NULL;
1123         attribute_argument_t **anchor = &first;
1124         if (token.kind != ')') do {
1125                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1126
1127                 /* is it an identifier */
1128                 if (token.kind == T_IDENTIFIER
1129                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1130                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1131                         argument->v.symbol = token.base.symbol;
1132                         eat(T_IDENTIFIER);
1133                 } else {
1134                         /* must be an expression */
1135                         expression_t *expression = parse_assignment_expression();
1136
1137                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1138                         argument->v.expression = expression;
1139                 }
1140
1141                 /* append argument */
1142                 *anchor = argument;
1143                 anchor  = &argument->next;
1144         } while (accept(','));
1145         expect(')');
1146         return first;
1147 }
1148
1149 static attribute_t *parse_attribute_asm(void)
1150 {
1151         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1152         eat(T_asm);
1153         expect('(');
1154         attribute->a.arguments = parse_attribute_arguments();
1155         return attribute;
1156 }
1157
1158 static attribute_t *parse_attribute_gnu_single(void)
1159 {
1160         /* parse "any-word" */
1161         symbol_t *const symbol = token.base.symbol;
1162         if (symbol == NULL) {
1163                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1164                 return NULL;
1165         }
1166
1167         attribute_kind_t  kind;
1168         char const *const name = symbol->string;
1169         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1170                 if (kind > ATTRIBUTE_GNU_LAST) {
1171                         /* special case for "__const" */
1172                         if (token.kind == T_const) {
1173                                 kind = ATTRIBUTE_GNU_CONST;
1174                                 break;
1175                         }
1176
1177                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1178                         /* TODO: we should still save the attribute in the list... */
1179                         kind = ATTRIBUTE_UNKNOWN;
1180                         break;
1181                 }
1182
1183                 const char *attribute_name = get_attribute_name(kind);
1184                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1185                         break;
1186         }
1187
1188         attribute_t *attribute = allocate_attribute_zero(kind);
1189         next_token();
1190
1191         /* parse arguments */
1192         if (accept('('))
1193                 attribute->a.arguments = parse_attribute_arguments();
1194
1195         return attribute;
1196 }
1197
1198 static attribute_t *parse_attribute_gnu(void)
1199 {
1200         attribute_t  *first  = NULL;
1201         attribute_t **anchor = &first;
1202
1203         eat(T___attribute__);
1204         add_anchor_token(')');
1205         add_anchor_token(',');
1206         expect('(');
1207         expect('(');
1208
1209         if (token.kind != ')') do {
1210                 attribute_t *attribute = parse_attribute_gnu_single();
1211                 if (attribute) {
1212                         *anchor = attribute;
1213                         anchor  = &attribute->next;
1214                 }
1215         } while (accept(','));
1216         rem_anchor_token(',');
1217         rem_anchor_token(')');
1218
1219         expect(')');
1220         expect(')');
1221         return first;
1222 }
1223
1224 /** Parse attributes. */
1225 static attribute_t *parse_attributes(attribute_t *first)
1226 {
1227         attribute_t **anchor = &first;
1228         for (;;) {
1229                 while (*anchor != NULL)
1230                         anchor = &(*anchor)->next;
1231
1232                 attribute_t *attribute;
1233                 switch (token.kind) {
1234                 case T___attribute__:
1235                         attribute = parse_attribute_gnu();
1236                         if (attribute == NULL)
1237                                 continue;
1238                         break;
1239
1240                 case T_asm:
1241                         attribute = parse_attribute_asm();
1242                         break;
1243
1244                 case T_cdecl:
1245                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1246                         eat(T_cdecl);
1247                         break;
1248
1249                 case T__fastcall:
1250                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1251                         eat(T__fastcall);
1252                         break;
1253
1254                 case T__forceinline:
1255                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1256                         eat(T__forceinline);
1257                         break;
1258
1259                 case T__stdcall:
1260                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1261                         eat(T__stdcall);
1262                         break;
1263
1264                 case T___thiscall:
1265                         /* TODO record modifier */
1266                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1267                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1268                         eat(T___thiscall);
1269                         break;
1270
1271                 default:
1272                         return first;
1273                 }
1274
1275                 *anchor = attribute;
1276                 anchor  = &attribute->next;
1277         }
1278 }
1279
1280 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1281
1282 static entity_t *determine_lhs_ent(expression_t *const expr,
1283                                    entity_t *lhs_ent)
1284 {
1285         switch (expr->kind) {
1286                 case EXPR_REFERENCE: {
1287                         entity_t *const entity = expr->reference.entity;
1288                         /* we should only find variables as lvalues... */
1289                         if (entity->base.kind != ENTITY_VARIABLE
1290                                         && entity->base.kind != ENTITY_PARAMETER)
1291                                 return NULL;
1292
1293                         return entity;
1294                 }
1295
1296                 case EXPR_ARRAY_ACCESS: {
1297                         expression_t *const ref = expr->array_access.array_ref;
1298                         entity_t     *      ent = NULL;
1299                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1300                                 ent     = determine_lhs_ent(ref, lhs_ent);
1301                                 lhs_ent = ent;
1302                         } else {
1303                                 mark_vars_read(ref, lhs_ent);
1304                         }
1305                         mark_vars_read(expr->array_access.index, lhs_ent);
1306                         return ent;
1307                 }
1308
1309                 case EXPR_SELECT: {
1310                         mark_vars_read(expr->select.compound, lhs_ent);
1311                         if (is_type_compound(skip_typeref(expr->base.type)))
1312                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1313                         return NULL;
1314                 }
1315
1316                 case EXPR_UNARY_DEREFERENCE: {
1317                         expression_t *const val = expr->unary.value;
1318                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1319                                 /* *&x is a NOP */
1320                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1321                         } else {
1322                                 mark_vars_read(val, NULL);
1323                                 return NULL;
1324                         }
1325                 }
1326
1327                 default:
1328                         mark_vars_read(expr, NULL);
1329                         return NULL;
1330         }
1331 }
1332
1333 #define ENT_ANY ((entity_t*)-1)
1334
1335 /**
1336  * Mark declarations, which are read.  This is used to detect variables, which
1337  * are never read.
1338  * Example:
1339  * x = x + 1;
1340  *   x is not marked as "read", because it is only read to calculate its own new
1341  *   value.
1342  *
1343  * x += y; y += x;
1344  *   x and y are not detected as "not read", because multiple variables are
1345  *   involved.
1346  */
1347 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1348 {
1349         switch (expr->kind) {
1350                 case EXPR_REFERENCE: {
1351                         entity_t *const entity = expr->reference.entity;
1352                         if (entity->kind != ENTITY_VARIABLE
1353                                         && entity->kind != ENTITY_PARAMETER)
1354                                 return;
1355
1356                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1357                                 entity->variable.read = true;
1358                         }
1359                         return;
1360                 }
1361
1362                 case EXPR_CALL:
1363                         // TODO respect pure/const
1364                         mark_vars_read(expr->call.function, NULL);
1365                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1366                                 mark_vars_read(arg->expression, NULL);
1367                         }
1368                         return;
1369
1370                 case EXPR_CONDITIONAL:
1371                         // TODO lhs_decl should depend on whether true/false have an effect
1372                         mark_vars_read(expr->conditional.condition, NULL);
1373                         if (expr->conditional.true_expression != NULL)
1374                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1375                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1376                         return;
1377
1378                 case EXPR_SELECT:
1379                         if (lhs_ent == ENT_ANY
1380                                         && !is_type_compound(skip_typeref(expr->base.type)))
1381                                 lhs_ent = NULL;
1382                         mark_vars_read(expr->select.compound, lhs_ent);
1383                         return;
1384
1385                 case EXPR_ARRAY_ACCESS: {
1386                         mark_vars_read(expr->array_access.index, lhs_ent);
1387                         expression_t *const ref = expr->array_access.array_ref;
1388                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1389                                 if (lhs_ent == ENT_ANY)
1390                                         lhs_ent = NULL;
1391                         }
1392                         mark_vars_read(ref, lhs_ent);
1393                         return;
1394                 }
1395
1396                 case EXPR_VA_ARG:
1397                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1398                         return;
1399
1400                 case EXPR_VA_COPY:
1401                         mark_vars_read(expr->va_copye.src, lhs_ent);
1402                         return;
1403
1404                 case EXPR_UNARY_CAST:
1405                         /* Special case: Use void cast to mark a variable as "read" */
1406                         if (is_type_void(skip_typeref(expr->base.type)))
1407                                 lhs_ent = NULL;
1408                         goto unary;
1409
1410
1411                 case EXPR_UNARY_THROW:
1412                         if (expr->unary.value == NULL)
1413                                 return;
1414                         /* FALLTHROUGH */
1415                 case EXPR_UNARY_DEREFERENCE:
1416                 case EXPR_UNARY_DELETE:
1417                 case EXPR_UNARY_DELETE_ARRAY:
1418                         if (lhs_ent == ENT_ANY)
1419                                 lhs_ent = NULL;
1420                         goto unary;
1421
1422                 case EXPR_UNARY_NEGATE:
1423                 case EXPR_UNARY_PLUS:
1424                 case EXPR_UNARY_COMPLEMENT:
1425                 case EXPR_UNARY_NOT:
1426                 case EXPR_UNARY_TAKE_ADDRESS:
1427                 case EXPR_UNARY_POSTFIX_INCREMENT:
1428                 case EXPR_UNARY_POSTFIX_DECREMENT:
1429                 case EXPR_UNARY_PREFIX_INCREMENT:
1430                 case EXPR_UNARY_PREFIX_DECREMENT:
1431                 case EXPR_UNARY_ASSUME:
1432                 case EXPR_UNARY_IMAG:
1433                 case EXPR_UNARY_REAL:
1434 unary:
1435                         mark_vars_read(expr->unary.value, lhs_ent);
1436                         return;
1437
1438                 case EXPR_BINARY_ADD:
1439                 case EXPR_BINARY_SUB:
1440                 case EXPR_BINARY_MUL:
1441                 case EXPR_BINARY_DIV:
1442                 case EXPR_BINARY_MOD:
1443                 case EXPR_BINARY_EQUAL:
1444                 case EXPR_BINARY_NOTEQUAL:
1445                 case EXPR_BINARY_LESS:
1446                 case EXPR_BINARY_LESSEQUAL:
1447                 case EXPR_BINARY_GREATER:
1448                 case EXPR_BINARY_GREATEREQUAL:
1449                 case EXPR_BINARY_BITWISE_AND:
1450                 case EXPR_BINARY_BITWISE_OR:
1451                 case EXPR_BINARY_BITWISE_XOR:
1452                 case EXPR_BINARY_LOGICAL_AND:
1453                 case EXPR_BINARY_LOGICAL_OR:
1454                 case EXPR_BINARY_SHIFTLEFT:
1455                 case EXPR_BINARY_SHIFTRIGHT:
1456                 case EXPR_BINARY_COMMA:
1457                 case EXPR_BINARY_ISGREATER:
1458                 case EXPR_BINARY_ISGREATEREQUAL:
1459                 case EXPR_BINARY_ISLESS:
1460                 case EXPR_BINARY_ISLESSEQUAL:
1461                 case EXPR_BINARY_ISLESSGREATER:
1462                 case EXPR_BINARY_ISUNORDERED:
1463                         mark_vars_read(expr->binary.left,  lhs_ent);
1464                         mark_vars_read(expr->binary.right, lhs_ent);
1465                         return;
1466
1467                 case EXPR_BINARY_ASSIGN:
1468                 case EXPR_BINARY_MUL_ASSIGN:
1469                 case EXPR_BINARY_DIV_ASSIGN:
1470                 case EXPR_BINARY_MOD_ASSIGN:
1471                 case EXPR_BINARY_ADD_ASSIGN:
1472                 case EXPR_BINARY_SUB_ASSIGN:
1473                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1474                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1475                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1476                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1477                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1478                         if (lhs_ent == ENT_ANY)
1479                                 lhs_ent = NULL;
1480                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1481                         mark_vars_read(expr->binary.right, lhs_ent);
1482                         return;
1483                 }
1484
1485                 case EXPR_VA_START:
1486                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1487                         return;
1488
1489                 case EXPR_LITERAL_CASES:
1490                 case EXPR_LITERAL_CHARACTER:
1491                 case EXPR_ERROR:
1492                 case EXPR_STRING_LITERAL:
1493                 case EXPR_COMPOUND_LITERAL: // TODO init?
1494                 case EXPR_SIZEOF:
1495                 case EXPR_CLASSIFY_TYPE:
1496                 case EXPR_ALIGNOF:
1497                 case EXPR_FUNCNAME:
1498                 case EXPR_BUILTIN_CONSTANT_P:
1499                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1500                 case EXPR_OFFSETOF:
1501                 case EXPR_STATEMENT: // TODO
1502                 case EXPR_LABEL_ADDRESS:
1503                 case EXPR_ENUM_CONSTANT:
1504                         return;
1505         }
1506
1507         panic("unhandled expression");
1508 }
1509
1510 static designator_t *parse_designation(void)
1511 {
1512         designator_t  *result = NULL;
1513         designator_t **anchor = &result;
1514
1515         for (;;) {
1516                 designator_t *designator;
1517                 switch (token.kind) {
1518                 case '[':
1519                         designator      = allocate_ast_zero(sizeof(designator[0]));
1520                         designator->pos = *HERE;
1521                         eat('[');
1522                         add_anchor_token(']');
1523                         add_anchor_token(T_DOTDOTDOT);
1524                         designator->array_index = parse_constant_expression();
1525                         if (accept(T_DOTDOTDOT)) {
1526                                 designator->range_last = parse_constant_expression();
1527                                 errorf(&designator->pos, "range initializer not supported");
1528                         }
1529                         rem_anchor_token(T_DOTDOTDOT);
1530                         rem_anchor_token(']');
1531                         expect(']');
1532                         break;
1533                 case '.':
1534                         designator      = allocate_ast_zero(sizeof(designator[0]));
1535                         designator->pos = *HERE;
1536                         eat('.');
1537                         designator->symbol = expect_identifier("while parsing designator", NULL);
1538                         if (!designator->symbol)
1539                                 return NULL;
1540                         break;
1541                 default:
1542                         expect('=');
1543                         return result;
1544                 }
1545
1546                 assert(designator != NULL);
1547                 *anchor = designator;
1548                 anchor  = &designator->next;
1549         }
1550 }
1551
1552 /**
1553  * Build an initializer from a given expression.
1554  */
1555 static initializer_t *initializer_from_expression(type_t *orig_type,
1556                                                   expression_t *expression)
1557 {
1558         /* TODO check that expression is a constant expression */
1559
1560         type_t *const type = skip_typeref(orig_type);
1561
1562         /* §6.7.8.14/15 char array may be initialized by string literals */
1563         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1564                 array_type_t *const array_type   = &type->array;
1565                 type_t       *const element_type = skip_typeref(array_type->element_type);
1566                 switch (expression->string_literal.value.encoding) {
1567                 case STRING_ENCODING_CHAR:
1568                 case STRING_ENCODING_UTF8: {
1569                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1570                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1571                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1572                                 goto make_string_init;
1573                         }
1574                         break;
1575                 }
1576
1577                 case STRING_ENCODING_CHAR16:
1578                 case STRING_ENCODING_CHAR32:
1579                 case STRING_ENCODING_WIDE: {
1580                         assert(is_type_pointer(expression->base.type));
1581                         type_t *const init_type = get_unqualified_type(expression->base.type->pointer.points_to);
1582                         if (types_compatible(get_unqualified_type(element_type), init_type)) {
1583 make_string_init:;
1584                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1585                                 init->value.value = expression;
1586                                 return init;
1587                         }
1588                         break;
1589                 }
1590                 }
1591         }
1592
1593         assign_error_t error = semantic_assign(type, expression);
1594         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1595                 return NULL;
1596         report_assign_error(error, type, expression, "initializer",
1597                             &expression->base.pos);
1598
1599         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1600         result->value.value = create_implicit_cast(expression, type);
1601
1602         return result;
1603 }
1604
1605 /**
1606  * Parses an scalar initializer.
1607  *
1608  * §6.7.8.11; eat {} without warning
1609  */
1610 static initializer_t *parse_scalar_initializer(type_t *type,
1611                                                bool must_be_constant)
1612 {
1613         /* there might be extra {} hierarchies */
1614         int braces = 0;
1615         if (token.kind == '{') {
1616                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1617                 do {
1618                         eat('{');
1619                         ++braces;
1620                 } while (token.kind == '{');
1621         }
1622
1623         expression_t *expression = parse_assignment_expression();
1624         mark_vars_read(expression, NULL);
1625         if (must_be_constant && !is_linker_constant(expression)) {
1626                 errorf(&expression->base.pos,
1627                        "initialisation expression '%E' is not constant",
1628                        expression);
1629         }
1630
1631         initializer_t *initializer = initializer_from_expression(type, expression);
1632
1633         if (initializer == NULL) {
1634                 errorf(&expression->base.pos,
1635                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1636                        expression, expression->base.type, type);
1637                 /* TODO */
1638                 return NULL;
1639         }
1640
1641         bool additional_warning_displayed = false;
1642         while (braces > 0) {
1643                 accept(',');
1644                 if (token.kind != '}') {
1645                         if (!additional_warning_displayed) {
1646                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1647                                 additional_warning_displayed = true;
1648                         }
1649                 }
1650                 eat_block();
1651                 braces--;
1652         }
1653
1654         return initializer;
1655 }
1656
1657 /**
1658  * An entry in the type path.
1659  */
1660 typedef struct type_path_entry_t type_path_entry_t;
1661 struct type_path_entry_t {
1662         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1663         union {
1664                 size_t         index;          /**< For array types: the current index. */
1665                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1666         } v;
1667 };
1668
1669 /**
1670  * A type path expression a position inside compound or array types.
1671  */
1672 typedef struct type_path_t type_path_t;
1673 struct type_path_t {
1674         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1675         type_t            *top_type;     /**< type of the element the path points */
1676         size_t             max_index;    /**< largest index in outermost array */
1677 };
1678
1679 /**
1680  * Prints a type path for debugging.
1681  */
1682 static __attribute__((unused)) void debug_print_type_path(
1683                 const type_path_t *path)
1684 {
1685         size_t len = ARR_LEN(path->path);
1686
1687         for (size_t i = 0; i < len; ++i) {
1688                 const type_path_entry_t *entry = & path->path[i];
1689
1690                 type_t *type = skip_typeref(entry->type);
1691                 if (is_type_compound(type)) {
1692                         /* in gcc mode structs can have no members */
1693                         if (entry->v.compound_entry == NULL) {
1694                                 assert(i == len-1);
1695                                 continue;
1696                         }
1697                         fprintf(stderr, ".%s",
1698                                 entry->v.compound_entry->base.symbol->string);
1699                 } else if (is_type_array(type)) {
1700                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1701                 } else {
1702                         fprintf(stderr, "-INVALID-");
1703                 }
1704         }
1705         if (path->top_type != NULL) {
1706                 fprintf(stderr, "  (");
1707                 print_type(path->top_type);
1708                 fprintf(stderr, ")");
1709         }
1710 }
1711
1712 /**
1713  * Return the top type path entry, i.e. in a path
1714  * (type).a.b returns the b.
1715  */
1716 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1717 {
1718         size_t len = ARR_LEN(path->path);
1719         assert(len > 0);
1720         return &path->path[len-1];
1721 }
1722
1723 /**
1724  * Enlarge the type path by an (empty) element.
1725  */
1726 static type_path_entry_t *append_to_type_path(type_path_t *path)
1727 {
1728         size_t len = ARR_LEN(path->path);
1729         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1730
1731         type_path_entry_t *result = & path->path[len];
1732         memset(result, 0, sizeof(result[0]));
1733         return result;
1734 }
1735
1736 /**
1737  * Descending into a sub-type. Enter the scope of the current top_type.
1738  */
1739 static void descend_into_subtype(type_path_t *path)
1740 {
1741         type_t *orig_top_type = path->top_type;
1742         type_t *top_type      = skip_typeref(orig_top_type);
1743
1744         type_path_entry_t *top = append_to_type_path(path);
1745         top->type              = top_type;
1746
1747         if (is_type_compound(top_type)) {
1748                 compound_t *const compound = top_type->compound.compound;
1749                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1750
1751                 if (entry != NULL) {
1752                         top->v.compound_entry = &entry->declaration;
1753                         path->top_type = entry->declaration.type;
1754                 } else {
1755                         path->top_type = NULL;
1756                 }
1757         } else if (is_type_array(top_type)) {
1758                 top->v.index   = 0;
1759                 path->top_type = top_type->array.element_type;
1760         } else {
1761                 assert(!is_type_valid(top_type));
1762         }
1763 }
1764
1765 /**
1766  * Pop an entry from the given type path, i.e. returning from
1767  * (type).a.b to (type).a
1768  */
1769 static void ascend_from_subtype(type_path_t *path)
1770 {
1771         type_path_entry_t *top = get_type_path_top(path);
1772
1773         path->top_type = top->type;
1774
1775         size_t len = ARR_LEN(path->path);
1776         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1777 }
1778
1779 /**
1780  * Pop entries from the given type path until the given
1781  * path level is reached.
1782  */
1783 static void ascend_to(type_path_t *path, size_t top_path_level)
1784 {
1785         size_t len = ARR_LEN(path->path);
1786
1787         while (len > top_path_level) {
1788                 ascend_from_subtype(path);
1789                 len = ARR_LEN(path->path);
1790         }
1791 }
1792
1793 static bool walk_designator(type_path_t *path, const designator_t *designator,
1794                             bool used_in_offsetof)
1795 {
1796         for (; designator != NULL; designator = designator->next) {
1797                 type_path_entry_t *top       = get_type_path_top(path);
1798                 type_t            *orig_type = top->type;
1799
1800                 type_t *type = skip_typeref(orig_type);
1801
1802                 if (designator->symbol != NULL) {
1803                         symbol_t *symbol = designator->symbol;
1804                         if (!is_type_compound(type)) {
1805                                 if (is_type_valid(type)) {
1806                                         errorf(&designator->pos,
1807                                                "'.%Y' designator used for non-compound type '%T'",
1808                                                symbol, orig_type);
1809                                 }
1810
1811                                 top->type             = type_error_type;
1812                                 top->v.compound_entry = NULL;
1813                                 orig_type             = type_error_type;
1814                         } else {
1815                                 compound_t *compound = type->compound.compound;
1816                                 entity_t   *iter     = compound->members.entities;
1817                                 for (; iter != NULL; iter = iter->base.next) {
1818                                         if (iter->base.symbol == symbol) {
1819                                                 break;
1820                                         }
1821                                 }
1822                                 if (iter == NULL) {
1823                                         errorf(&designator->pos,
1824                                                "'%T' has no member named '%Y'", orig_type, symbol);
1825                                         return false;
1826                                 }
1827                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1828                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1829                                         errorf(&designator->pos,
1830                                                    "offsetof designator '%Y' must not specify bitfield",
1831                                                    symbol);
1832                                         return false;
1833                                 }
1834
1835                                 top->type             = orig_type;
1836                                 top->v.compound_entry = &iter->declaration;
1837                                 orig_type             = iter->declaration.type;
1838                         }
1839                 } else {
1840                         expression_t *array_index = designator->array_index;
1841                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1842                                 return true;
1843
1844                         if (!is_type_array(type)) {
1845                                 if (is_type_valid(type)) {
1846                                         errorf(&designator->pos,
1847                                                "[%E] designator used for non-array type '%T'",
1848                                                array_index, orig_type);
1849                                 }
1850                                 return false;
1851                         }
1852
1853                         long index = fold_constant_to_int(array_index);
1854                         if (!used_in_offsetof) {
1855                                 if (index < 0) {
1856                                         errorf(&designator->pos,
1857                                                "array index [%E] must be positive", array_index);
1858                                 } else if (type->array.size_constant) {
1859                                         long array_size = type->array.size;
1860                                         if (index >= array_size) {
1861                                                 errorf(&designator->pos,
1862                                                        "designator [%E] (%d) exceeds array size %d",
1863                                                        array_index, index, array_size);
1864                                         }
1865                                 }
1866                         }
1867
1868                         top->type    = orig_type;
1869                         top->v.index = (size_t) index;
1870                         orig_type    = type->array.element_type;
1871                 }
1872                 path->top_type = orig_type;
1873
1874                 if (designator->next != NULL) {
1875                         descend_into_subtype(path);
1876                 }
1877         }
1878         return true;
1879 }
1880
1881 static void advance_current_object(type_path_t *path, size_t top_path_level)
1882 {
1883         type_path_entry_t *top = get_type_path_top(path);
1884
1885         type_t *type = skip_typeref(top->type);
1886         if (is_type_union(type)) {
1887                 /* in unions only the first element is initialized */
1888                 top->v.compound_entry = NULL;
1889         } else if (is_type_struct(type)) {
1890                 declaration_t *entry = top->v.compound_entry;
1891
1892                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1893                 if (next_entity != NULL) {
1894                         assert(is_declaration(next_entity));
1895                         entry = &next_entity->declaration;
1896                 } else {
1897                         entry = NULL;
1898                 }
1899
1900                 top->v.compound_entry = entry;
1901                 if (entry != NULL) {
1902                         path->top_type = entry->type;
1903                         return;
1904                 }
1905         } else if (is_type_array(type)) {
1906                 assert(is_type_array(type));
1907
1908                 top->v.index++;
1909
1910                 if (!type->array.size_constant || top->v.index < type->array.size) {
1911                         return;
1912                 }
1913         } else {
1914                 assert(!is_type_valid(type));
1915                 return;
1916         }
1917
1918         /* we're past the last member of the current sub-aggregate, try if we
1919          * can ascend in the type hierarchy and continue with another subobject */
1920         size_t len = ARR_LEN(path->path);
1921
1922         if (len > top_path_level) {
1923                 ascend_from_subtype(path);
1924                 advance_current_object(path, top_path_level);
1925         } else {
1926                 path->top_type = NULL;
1927         }
1928 }
1929
1930 /**
1931  * skip any {...} blocks until a closing bracket is reached.
1932  */
1933 static void skip_initializers(void)
1934 {
1935         accept('{');
1936
1937         while (token.kind != '}') {
1938                 if (token.kind == T_EOF)
1939                         return;
1940                 if (token.kind == '{') {
1941                         eat_block();
1942                         continue;
1943                 }
1944                 next_token();
1945         }
1946 }
1947
1948 static initializer_t *create_empty_initializer(void)
1949 {
1950         static initializer_t empty_initializer
1951                 = { .list = { { INITIALIZER_LIST }, 0 } };
1952         return &empty_initializer;
1953 }
1954
1955 /**
1956  * Parse a part of an initialiser for a struct or union,
1957  */
1958 static initializer_t *parse_sub_initializer(type_path_t *path,
1959                 type_t *outer_type, size_t top_path_level,
1960                 parse_initializer_env_t *env)
1961 {
1962         if (token.kind == '}') {
1963                 /* empty initializer */
1964                 return create_empty_initializer();
1965         }
1966
1967         initializer_t *result = NULL;
1968
1969         type_t *orig_type = path->top_type;
1970         type_t *type      = NULL;
1971
1972         if (orig_type == NULL) {
1973                 /* We are initializing an empty compound. */
1974         } else {
1975                 type = skip_typeref(orig_type);
1976         }
1977
1978         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1979
1980         while (true) {
1981                 designator_t *designator = NULL;
1982                 if (token.kind == '.' || token.kind == '[') {
1983                         designator = parse_designation();
1984                         goto finish_designator;
1985                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1986                         /* GNU-style designator ("identifier: value") */
1987                         designator         = allocate_ast_zero(sizeof(designator[0]));
1988                         designator->pos    = *HERE;
1989                         designator->symbol = token.base.symbol;
1990                         eat(T_IDENTIFIER);
1991                         eat(':');
1992
1993 finish_designator:
1994                         /* reset path to toplevel, evaluate designator from there */
1995                         ascend_to(path, top_path_level);
1996                         if (!walk_designator(path, designator, false)) {
1997                                 /* can't continue after designation error */
1998                                 goto end_error;
1999                         }
2000
2001                         initializer_t *designator_initializer
2002                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2003                         designator_initializer->designator.designator = designator;
2004                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2005
2006                         orig_type = path->top_type;
2007                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2008                 }
2009
2010                 initializer_t *sub;
2011
2012                 if (token.kind == '{') {
2013                         if (type != NULL && is_type_scalar(type)) {
2014                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2015                         } else {
2016                                 if (type == NULL) {
2017                                         if (env->entity != NULL) {
2018                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2019                                         } else {
2020                                                 errorf(HERE, "extra brace group at end of initializer");
2021                                         }
2022                                         eat('{');
2023                                 } else {
2024                                         eat('{');
2025                                         descend_into_subtype(path);
2026                                 }
2027
2028                                 add_anchor_token('}');
2029                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2030                                                             env);
2031                                 rem_anchor_token('}');
2032
2033                                 expect('}');
2034
2035                                 if (!type)
2036                                         goto error_parse_next;
2037
2038                                 ascend_from_subtype(path);
2039                         }
2040                 } else {
2041                         /* must be an expression */
2042                         expression_t *expression = parse_assignment_expression();
2043                         mark_vars_read(expression, NULL);
2044
2045                         if (env->must_be_constant && !is_linker_constant(expression)) {
2046                                 errorf(&expression->base.pos,
2047                                        "Initialisation expression '%E' is not constant",
2048                                        expression);
2049                         }
2050
2051                         if (type == NULL) {
2052                                 /* we are already outside, ... */
2053                                 if (outer_type == NULL)
2054                                         goto error_parse_next;
2055                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2056                                 if (is_type_compound(outer_type_skip) &&
2057                                                 !outer_type_skip->compound.compound->complete) {
2058                                         goto error_parse_next;
2059                                 }
2060
2061                                 position_t const* const pos = &expression->base.pos;
2062                                 if (env->entity != NULL) {
2063                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2064                                 } else {
2065                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2066                                 }
2067                                 goto error_parse_next;
2068                         }
2069
2070                         /* handle { "string" } special case */
2071                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2072                                 result = initializer_from_expression(outer_type, expression);
2073                                 if (result != NULL) {
2074                                         accept(',');
2075                                         if (token.kind != '}') {
2076                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2077                                         }
2078                                         /* TODO: eat , ... */
2079                                         goto out;
2080                                 }
2081                         }
2082
2083                         /* descend into subtypes until expression matches type */
2084                         while (true) {
2085                                 orig_type = path->top_type;
2086                                 type      = skip_typeref(orig_type);
2087
2088                                 sub = initializer_from_expression(orig_type, expression);
2089                                 if (sub != NULL) {
2090                                         break;
2091                                 }
2092                                 if (!is_type_valid(type)) {
2093                                         goto end_error;
2094                                 }
2095                                 if (is_type_scalar(type)) {
2096                                         errorf(&expression->base.pos,
2097                                                         "expression '%E' doesn't match expected type '%T'",
2098                                                         expression, orig_type);
2099                                         goto end_error;
2100                                 }
2101
2102                                 descend_into_subtype(path);
2103                         }
2104                 }
2105
2106                 /* update largest index of top array */
2107                 const type_path_entry_t *first      = &path->path[0];
2108                 type_t                  *first_type = first->type;
2109                 first_type                          = skip_typeref(first_type);
2110                 if (is_type_array(first_type)) {
2111                         size_t index = first->v.index;
2112                         if (index > path->max_index)
2113                                 path->max_index = index;
2114                 }
2115
2116                 /* append to initializers list */
2117                 ARR_APP1(initializer_t*, initializers, sub);
2118
2119 error_parse_next:
2120                 if (!accept(','))
2121                         break;
2122                 if (token.kind == '}') {
2123                         break;
2124                 }
2125
2126                 if (type != NULL) {
2127                         /* advance to the next declaration if we are not at the end */
2128                         advance_current_object(path, top_path_level);
2129                         orig_type = path->top_type;
2130                         if (orig_type != NULL)
2131                                 type = skip_typeref(orig_type);
2132                         else
2133                                 type = NULL;
2134                 }
2135         }
2136
2137         size_t len  = ARR_LEN(initializers);
2138         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2139         result = allocate_ast_zero(size);
2140         result->kind     = INITIALIZER_LIST;
2141         result->list.len = len;
2142         memcpy(&result->list.initializers, initializers,
2143                len * sizeof(initializers[0]));
2144         goto out;
2145
2146 end_error:
2147         skip_initializers();
2148 out:
2149         DEL_ARR_F(initializers);
2150         ascend_to(path, top_path_level+1);
2151         return result;
2152 }
2153
2154 static expression_t *make_size_literal(size_t value)
2155 {
2156         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2157         literal->base.type    = type_size_t;
2158
2159         char buf[128];
2160         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2161         literal->literal.value = make_string(buf);
2162
2163         return literal;
2164 }
2165
2166 /**
2167  * Parses an initializer. Parsers either a compound literal
2168  * (env->declaration == NULL) or an initializer of a declaration.
2169  */
2170 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2171 {
2172         type_t        *type      = skip_typeref(env->type);
2173         size_t         max_index = 0;
2174         initializer_t *result;
2175
2176         if (is_type_scalar(type)) {
2177                 result = parse_scalar_initializer(type, env->must_be_constant);
2178         } else if (token.kind == '{') {
2179                 eat('{');
2180
2181                 type_path_t path;
2182                 memset(&path, 0, sizeof(path));
2183                 path.top_type = env->type;
2184                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2185
2186                 descend_into_subtype(&path);
2187
2188                 add_anchor_token('}');
2189                 result = parse_sub_initializer(&path, env->type, 1, env);
2190                 rem_anchor_token('}');
2191
2192                 max_index = path.max_index;
2193                 DEL_ARR_F(path.path);
2194
2195                 expect('}');
2196         } else {
2197                 /* parse_scalar_initializer() also works in this case: we simply
2198                  * have an expression without {} around it */
2199                 result = parse_scalar_initializer(type, env->must_be_constant);
2200         }
2201
2202         /* §6.7.8:22 array initializers for arrays with unknown size determine
2203          * the array type size */
2204         if (is_type_array(type) && type->array.size_expression == NULL
2205                         && result != NULL) {
2206                 size_t size;
2207                 switch (result->kind) {
2208                 case INITIALIZER_LIST:
2209                         assert(max_index != 0xdeadbeaf);
2210                         size = max_index + 1;
2211                         break;
2212
2213                 case INITIALIZER_STRING: {
2214                         size = get_string_len(&get_init_string(result)->value) + 1;
2215                         break;
2216                 }
2217
2218                 case INITIALIZER_DESIGNATOR:
2219                 case INITIALIZER_VALUE:
2220                         /* can happen for parse errors */
2221                         size = 0;
2222                         break;
2223
2224                 default:
2225                         internal_errorf(HERE, "invalid initializer type");
2226                 }
2227
2228                 type_t *new_type = duplicate_type(type);
2229
2230                 new_type->array.size_expression   = make_size_literal(size);
2231                 new_type->array.size_constant     = true;
2232                 new_type->array.has_implicit_size = true;
2233                 new_type->array.size              = size;
2234                 env->type = new_type;
2235         }
2236
2237         return result;
2238 }
2239
2240 static void append_entity(scope_t *scope, entity_t *entity)
2241 {
2242         if (scope->last_entity != NULL) {
2243                 scope->last_entity->base.next = entity;
2244         } else {
2245                 scope->entities = entity;
2246         }
2247         entity->base.parent_entity = current_entity;
2248         scope->last_entity         = entity;
2249 }
2250
2251
2252 static compound_t *parse_compound_type_specifier(bool is_struct)
2253 {
2254         position_t const pos = *HERE;
2255         eat(is_struct ? T_struct : T_union);
2256
2257         symbol_t    *symbol     = NULL;
2258         entity_t    *entity     = NULL;
2259         attribute_t *attributes = NULL;
2260
2261         if (token.kind == T___attribute__) {
2262                 attributes = parse_attributes(NULL);
2263         }
2264
2265         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2266         if (token.kind == T_IDENTIFIER) {
2267                 /* the compound has a name, check if we have seen it already */
2268                 symbol = token.base.symbol;
2269                 entity = get_tag(symbol, kind);
2270                 eat(T_IDENTIFIER);
2271
2272                 if (entity != NULL) {
2273                         if (entity->base.parent_scope != current_scope &&
2274                             (token.kind == '{' || token.kind == ';')) {
2275                                 /* we're in an inner scope and have a definition. Shadow
2276                                  * existing definition in outer scope */
2277                                 entity = NULL;
2278                         } else if (entity->compound.complete && token.kind == '{') {
2279                                 position_t const *const ppos = &entity->base.pos;
2280                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2281                                 /* clear members in the hope to avoid further errors */
2282                                 entity->compound.members.entities = NULL;
2283                         }
2284                 }
2285         } else if (token.kind != '{') {
2286                 char const *const msg =
2287                         is_struct ? "while parsing struct type specifier" :
2288                                     "while parsing union type specifier";
2289                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2290
2291                 return NULL;
2292         }
2293
2294         if (entity == NULL) {
2295                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2296                 entity->compound.alignment = 1;
2297                 entity->base.parent_scope  = current_scope;
2298                 if (symbol != NULL) {
2299                         environment_push(entity);
2300                 }
2301                 append_entity(current_scope, entity);
2302         }
2303
2304         if (token.kind == '{') {
2305                 parse_compound_type_entries(&entity->compound);
2306
2307                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2308                 if (symbol == NULL) {
2309                         assert(anonymous_entity == NULL);
2310                         anonymous_entity = entity;
2311                 }
2312         }
2313
2314         if (attributes != NULL) {
2315                 entity->compound.attributes = attributes;
2316                 handle_entity_attributes(attributes, entity);
2317         }
2318
2319         return &entity->compound;
2320 }
2321
2322 static void parse_enum_entries(type_t *const enum_type)
2323 {
2324         eat('{');
2325
2326         if (token.kind == '}') {
2327                 errorf(HERE, "empty enum not allowed");
2328                 eat('}');
2329                 return;
2330         }
2331
2332         add_anchor_token('}');
2333         add_anchor_token(',');
2334         do {
2335                 add_anchor_token('=');
2336                 position_t pos;
2337                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2338                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2339                 entity->enum_value.enum_type = enum_type;
2340                 rem_anchor_token('=');
2341
2342                 if (accept('=')) {
2343                         expression_t *value = parse_constant_expression();
2344
2345                         value = create_implicit_cast(value, enum_type);
2346                         entity->enum_value.value = value;
2347
2348                         /* TODO semantic */
2349                 }
2350
2351                 record_entity(entity, false);
2352         } while (accept(',') && token.kind != '}');
2353         rem_anchor_token(',');
2354         rem_anchor_token('}');
2355
2356         expect('}');
2357 }
2358
2359 static type_t *parse_enum_specifier(void)
2360 {
2361         position_t const pos = *HERE;
2362         entity_t        *entity;
2363         symbol_t        *symbol;
2364
2365         eat(T_enum);
2366         switch (token.kind) {
2367                 case T_IDENTIFIER:
2368                         symbol = token.base.symbol;
2369                         entity = get_tag(symbol, ENTITY_ENUM);
2370                         eat(T_IDENTIFIER);
2371
2372                         if (entity != NULL) {
2373                                 if (entity->base.parent_scope != current_scope &&
2374                                                 (token.kind == '{' || token.kind == ';')) {
2375                                         /* we're in an inner scope and have a definition. Shadow
2376                                          * existing definition in outer scope */
2377                                         entity = NULL;
2378                                 } else if (entity->enume.complete && token.kind == '{') {
2379                                         position_t const *const ppos = &entity->base.pos;
2380                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2381                                 }
2382                         }
2383                         break;
2384
2385                 case '{':
2386                         entity = NULL;
2387                         symbol = NULL;
2388                         break;
2389
2390                 default:
2391                         parse_error_expected("while parsing enum type specifier",
2392                                         T_IDENTIFIER, '{', NULL);
2393                         return NULL;
2394         }
2395
2396         if (entity == NULL) {
2397                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2398                 entity->base.parent_scope = current_scope;
2399         }
2400
2401         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2402         type->enumt.enume      = &entity->enume;
2403         type->enumt.base.akind = ATOMIC_TYPE_INT;
2404
2405         if (token.kind == '{') {
2406                 if (symbol != NULL) {
2407                         environment_push(entity);
2408                 }
2409                 append_entity(current_scope, entity);
2410                 entity->enume.complete = true;
2411
2412                 parse_enum_entries(type);
2413                 parse_attributes(NULL);
2414
2415                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2416                 if (symbol == NULL) {
2417                         assert(anonymous_entity == NULL);
2418                         anonymous_entity = entity;
2419                 }
2420         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2421                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2422         }
2423
2424         return type;
2425 }
2426
2427 /**
2428  * if a symbol is a typedef to another type, return true
2429  */
2430 static bool is_typedef_symbol(symbol_t *symbol)
2431 {
2432         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2433         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2434 }
2435
2436 static type_t *parse_typeof(void)
2437 {
2438         eat(T___typeof__);
2439
2440         type_t *type;
2441
2442         add_anchor_token(')');
2443         expect('(');
2444
2445         expression_t *expression  = NULL;
2446
2447         switch (token.kind) {
2448         case T_IDENTIFIER:
2449                 if (is_typedef_symbol(token.base.symbol)) {
2450         DECLARATION_START
2451                         type = parse_typename();
2452                 } else {
2453         default:
2454                         expression = parse_expression();
2455                         type       = revert_automatic_type_conversion(expression);
2456                 }
2457                 break;
2458         }
2459
2460         rem_anchor_token(')');
2461         expect(')');
2462
2463         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2464         typeof_type->typeoft.expression  = expression;
2465         typeof_type->typeoft.typeof_type = type;
2466
2467         return typeof_type;
2468 }
2469
2470 typedef enum specifiers_t {
2471         SPECIFIER_NONE      = 0,
2472         SPECIFIER_SIGNED    = 1 << 0,
2473         SPECIFIER_UNSIGNED  = 1 << 1,
2474         SPECIFIER_LONG      = 1 << 2,
2475         SPECIFIER_INT       = 1 << 3,
2476         SPECIFIER_DOUBLE    = 1 << 4,
2477         SPECIFIER_CHAR      = 1 << 5,
2478         SPECIFIER_WCHAR_T   = 1 << 6,
2479         SPECIFIER_SHORT     = 1 << 7,
2480         SPECIFIER_LONG_LONG = 1 << 8,
2481         SPECIFIER_FLOAT     = 1 << 9,
2482         SPECIFIER_BOOL      = 1 << 10,
2483         SPECIFIER_VOID      = 1 << 11,
2484         SPECIFIER_INT8      = 1 << 12,
2485         SPECIFIER_INT16     = 1 << 13,
2486         SPECIFIER_INT32     = 1 << 14,
2487         SPECIFIER_INT64     = 1 << 15,
2488         SPECIFIER_INT128    = 1 << 16,
2489         SPECIFIER_COMPLEX   = 1 << 17,
2490         SPECIFIER_IMAGINARY = 1 << 18,
2491 } specifiers_t;
2492
2493 static type_t *get_typedef_type(symbol_t *symbol)
2494 {
2495         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2496         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2497                 return NULL;
2498
2499         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2500         type->typedeft.typedefe = &entity->typedefe;
2501
2502         return type;
2503 }
2504
2505 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2506 {
2507         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2508
2509         add_anchor_token(')');
2510         add_anchor_token(',');
2511         expect('(');
2512
2513         do {
2514                 add_anchor_token('=');
2515                 position_t pos;
2516                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2517                 rem_anchor_token('=');
2518
2519                 symbol_t **prop = NULL;
2520                 if (prop_sym) {
2521                         if (streq(prop_sym->string, "put")) {
2522                                 prop = &property->put_symbol;
2523                         } else if (streq(prop_sym->string, "get")) {
2524                                 prop = &property->get_symbol;
2525                         } else {
2526                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2527                         }
2528                 }
2529
2530                 add_anchor_token(T_IDENTIFIER);
2531                 expect('=');
2532                 rem_anchor_token(T_IDENTIFIER);
2533
2534                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2535                 if (prop != NULL)
2536                         *prop = sym ? sym : sym_anonymous;
2537         } while (accept(','));
2538         rem_anchor_token(',');
2539         rem_anchor_token(')');
2540
2541         attribute->a.property = property;
2542
2543         expect(')');
2544         return attribute;
2545 }
2546
2547 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2548 {
2549         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2550         if (accept(T_restrict)) {
2551                 kind = ATTRIBUTE_MS_RESTRICT;
2552         } else if (token.kind == T_IDENTIFIER) {
2553                 char const *const name = token.base.symbol->string;
2554                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2555                      ++k) {
2556                         const char *attribute_name = get_attribute_name(k);
2557                         if (attribute_name != NULL && streq(attribute_name, name)) {
2558                                 kind = k;
2559                                 break;
2560                         }
2561                 }
2562
2563                 if (kind == ATTRIBUTE_UNKNOWN) {
2564                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2565                 }
2566         } else {
2567                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2568                 return NULL;
2569         }
2570
2571         attribute_t *attribute = allocate_attribute_zero(kind);
2572         eat(T_IDENTIFIER);
2573
2574         if (kind == ATTRIBUTE_MS_PROPERTY) {
2575                 return parse_attribute_ms_property(attribute);
2576         }
2577
2578         /* parse arguments */
2579         if (accept('('))
2580                 attribute->a.arguments = parse_attribute_arguments();
2581
2582         return attribute;
2583 }
2584
2585 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2586 {
2587         eat(T__declspec);
2588
2589         add_anchor_token(')');
2590         expect('(');
2591         if (token.kind != ')') {
2592                 attribute_t **anchor = &first;
2593                 do {
2594                         while (*anchor != NULL)
2595                                 anchor = &(*anchor)->next;
2596
2597                         attribute_t *attribute
2598                                 = parse_microsoft_extended_decl_modifier_single();
2599                         if (attribute == NULL)
2600                                 break;
2601
2602                         *anchor = attribute;
2603                         anchor  = &attribute->next;
2604                 } while (accept(','));
2605         }
2606         rem_anchor_token(')');
2607         expect(')');
2608         return first;
2609 }
2610
2611 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2612 {
2613         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2614         if (is_declaration(entity)) {
2615                 entity->declaration.type     = type_error_type;
2616                 entity->declaration.implicit = true;
2617         } else if (kind == ENTITY_TYPEDEF) {
2618                 entity->typedefe.type    = type_error_type;
2619                 entity->typedefe.builtin = true;
2620         }
2621         if (kind != ENTITY_COMPOUND_MEMBER)
2622                 record_entity(entity, false);
2623         return entity;
2624 }
2625
2626 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2627 {
2628         type_t            *type            = NULL;
2629         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2630         unsigned           type_specifiers = 0;
2631         bool               newtype         = false;
2632         bool               saw_error       = false;
2633
2634         memset(specifiers, 0, sizeof(*specifiers));
2635         specifiers->pos = *HERE;
2636
2637         while (true) {
2638                 specifiers->attributes = parse_attributes(specifiers->attributes);
2639
2640                 switch (token.kind) {
2641                 /* storage class */
2642 #define MATCH_STORAGE_CLASS(token, class)                                  \
2643                 case token:                                                        \
2644                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2645                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2646                         }                                                              \
2647                         specifiers->storage_class = class;                             \
2648                         if (specifiers->thread_local)                                  \
2649                                 goto check_thread_storage_class;                           \
2650                         eat(token); \
2651                         break;
2652
2653                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2654                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2655                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2656                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2657                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2658
2659                 case T__declspec:
2660                         specifiers->attributes
2661                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2662                         break;
2663
2664                 case T__Thread_local:
2665                         if (specifiers->thread_local) {
2666                                 errorf(HERE, "duplicate %K", &token);
2667                         } else {
2668                                 specifiers->thread_local = true;
2669 check_thread_storage_class:
2670                                 switch (specifiers->storage_class) {
2671                                         case STORAGE_CLASS_EXTERN:
2672                                         case STORAGE_CLASS_NONE:
2673                                         case STORAGE_CLASS_STATIC:
2674                                                 break;
2675
2676                                                 char const* wrong;
2677                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2678                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2679                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2680 wrong_thread_storage_class:
2681                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2682                                                 break;
2683                                 }
2684                         }
2685                         next_token();
2686                         break;
2687
2688                 /* type qualifiers */
2689 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2690                 case token:                                                     \
2691                         qualifiers |= qualifier;                                    \
2692                         eat(token); \
2693                         break
2694
2695                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2696                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2697                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2698                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2699                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2700                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2701                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2702                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2703
2704                 /* type specifiers */
2705 #define MATCH_SPECIFIER(token, specifier, name)                         \
2706                 case token:                                                     \
2707                         if (type_specifiers & specifier) {                           \
2708                                 errorf(HERE, "multiple " name " type specifiers given"); \
2709                         } else {                                                    \
2710                                 type_specifiers |= specifier;                           \
2711                         }                                                           \
2712                         eat(token); \
2713                         break
2714
2715                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2716                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2717                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2718                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2719                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2720                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2721                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2722                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2723                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2724                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2725                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2726                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2727                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2728                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2729                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2730                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2731                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2732                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2733
2734                 case T_inline:
2735                         eat(T_inline);
2736                         specifiers->is_inline = true;
2737                         break;
2738
2739 #if 0
2740                 case T__forceinline:
2741                         eat(T__forceinline);
2742                         specifiers->modifiers |= DM_FORCEINLINE;
2743                         break;
2744 #endif
2745
2746                 case T_long:
2747                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2748                                 errorf(HERE, "too many long type specifiers given");
2749                         } else if (type_specifiers & SPECIFIER_LONG) {
2750                                 type_specifiers |= SPECIFIER_LONG_LONG;
2751                         } else {
2752                                 type_specifiers |= SPECIFIER_LONG;
2753                         }
2754                         eat(T_long);
2755                         break;
2756
2757 #define CHECK_DOUBLE_TYPE() \
2758         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2759
2760                 case T_struct:
2761                         CHECK_DOUBLE_TYPE();
2762                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2763
2764                         type->compound.compound = parse_compound_type_specifier(true);
2765                         break;
2766                 case T_union:
2767                         CHECK_DOUBLE_TYPE();
2768                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2769                         type->compound.compound = parse_compound_type_specifier(false);
2770                         break;
2771                 case T_enum:
2772                         CHECK_DOUBLE_TYPE();
2773                         type = parse_enum_specifier();
2774                         break;
2775                 case T___typeof__:
2776                         CHECK_DOUBLE_TYPE();
2777                         type = parse_typeof();
2778                         break;
2779                 case T___builtin_va_list:
2780                         CHECK_DOUBLE_TYPE();
2781                         type = duplicate_type(type_valist);
2782                         eat(T___builtin_va_list);
2783                         break;
2784
2785                 case T_IDENTIFIER: {
2786                         /* only parse identifier if we haven't found a type yet */
2787                         if (type != NULL || type_specifiers != 0) {
2788                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2789                                  * declaration, so it doesn't generate errors about expecting '(' or
2790                                  * '{' later on. */
2791                                 switch (look_ahead(1)->kind) {
2792                                         STORAGE_CLASSES
2793                                         TYPE_SPECIFIERS
2794                                         case T_const:
2795                                         case T_restrict:
2796                                         case T_volatile:
2797                                         case T_inline:
2798                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2799                                         case T_IDENTIFIER:
2800                                         case '&':
2801                                         case '*':
2802                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2803                                                 eat(T_IDENTIFIER);
2804                                                 continue;
2805
2806                                         default:
2807                                                 goto finish_specifiers;
2808                                 }
2809                         }
2810
2811                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2812                         if (typedef_type == NULL) {
2813                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2814                                  * declaration, so it doesn't generate 'implicit int' followed by more
2815                                  * errors later on. */
2816                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2817                                 switch (la1_type) {
2818                                         DECLARATION_START
2819                                         case T_IDENTIFIER:
2820                                         case '&':
2821                                         case '*': {
2822                                                 errorf(HERE, "%K does not name a type", &token);
2823
2824                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2825
2826                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2827                                                 type->typedeft.typedefe = &entity->typedefe;
2828
2829                                                 eat(T_IDENTIFIER);
2830                                                 saw_error = true;
2831                                                 continue;
2832                                         }
2833
2834                                         default:
2835                                                 goto finish_specifiers;
2836                                 }
2837                         }
2838
2839                         eat(T_IDENTIFIER);
2840                         type = typedef_type;
2841                         break;
2842                 }
2843
2844                 /* function specifier */
2845                 default:
2846                         goto finish_specifiers;
2847                 }
2848         }
2849
2850 finish_specifiers:
2851         specifiers->attributes = parse_attributes(specifiers->attributes);
2852
2853         if (type == NULL || (saw_error && type_specifiers != 0)) {
2854                 position_t const* const pos = &specifiers->pos;
2855                 atomic_type_kind_t atomic_type;
2856
2857                 /* match valid basic types */
2858                 switch (type_specifiers & ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2859                 case SPECIFIER_VOID:
2860                         if (type_specifiers & (SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2861                                 if (type_specifiers & SPECIFIER_COMPLEX)
2862                                         errorf(pos, "_Complex specifier is invalid for void");
2863                                 if (type_specifiers & SPECIFIER_IMAGINARY)
2864                                         errorf(pos, "_Imaginary specifier is invalid for void");
2865                                 type_specifiers &= ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY);
2866                         }
2867                         atomic_type = ATOMIC_TYPE_VOID;
2868                         break;
2869                 case SPECIFIER_WCHAR_T:
2870                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2871                         break;
2872                 case SPECIFIER_CHAR:
2873                         atomic_type = ATOMIC_TYPE_CHAR;
2874                         break;
2875                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2876                         atomic_type = ATOMIC_TYPE_SCHAR;
2877                         break;
2878                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2879                         atomic_type = ATOMIC_TYPE_UCHAR;
2880                         break;
2881                 case SPECIFIER_SHORT:
2882                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2883                 case SPECIFIER_SHORT | SPECIFIER_INT:
2884                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2885                         atomic_type = ATOMIC_TYPE_SHORT;
2886                         break;
2887                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2888                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2889                         atomic_type = ATOMIC_TYPE_USHORT;
2890                         break;
2891                 case SPECIFIER_INT:
2892                 case SPECIFIER_SIGNED:
2893                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2894                         atomic_type = ATOMIC_TYPE_INT;
2895                         break;
2896                 case SPECIFIER_UNSIGNED:
2897                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2898                         atomic_type = ATOMIC_TYPE_UINT;
2899                         break;
2900                 case SPECIFIER_LONG:
2901                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2902                 case SPECIFIER_LONG | SPECIFIER_INT:
2903                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2904                         atomic_type = ATOMIC_TYPE_LONG;
2905                         break;
2906                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2907                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2908                         atomic_type = ATOMIC_TYPE_ULONG;
2909                         break;
2910
2911                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2912                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2913                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2914                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2915                         | SPECIFIER_INT:
2916                         atomic_type = ATOMIC_TYPE_LONGLONG;
2917                         goto warn_about_long_long;
2918
2919                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2920                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2921                         | SPECIFIER_INT:
2922                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2923 warn_about_long_long:
2924                         warningf(WARN_LONG_LONG, &specifiers->pos, "ISO C90 does not support 'long long'");
2925                         break;
2926
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2928                         atomic_type = unsigned_int8_type_kind;
2929                         break;
2930
2931                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2932                         atomic_type = unsigned_int16_type_kind;
2933                         break;
2934
2935                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2936                         atomic_type = unsigned_int32_type_kind;
2937                         break;
2938
2939                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2940                         atomic_type = unsigned_int64_type_kind;
2941                         break;
2942
2943                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2944                         atomic_type = unsigned_int128_type_kind;
2945                         break;
2946
2947                 case SPECIFIER_INT8:
2948                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2949                         atomic_type = int8_type_kind;
2950                         break;
2951
2952                 case SPECIFIER_INT16:
2953                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2954                         atomic_type = int16_type_kind;
2955                         break;
2956
2957                 case SPECIFIER_INT32:
2958                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2959                         atomic_type = int32_type_kind;
2960                         break;
2961
2962                 case SPECIFIER_INT64:
2963                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2964                         atomic_type = int64_type_kind;
2965                         break;
2966
2967                 case SPECIFIER_INT128:
2968                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2969                         atomic_type = int128_type_kind;
2970                         break;
2971
2972                 case SPECIFIER_FLOAT:
2973                         atomic_type = ATOMIC_TYPE_FLOAT;
2974                         break;
2975                 case SPECIFIER_DOUBLE:
2976                         atomic_type = ATOMIC_TYPE_DOUBLE;
2977                         break;
2978                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2979                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2980                         break;
2981                 case SPECIFIER_BOOL:
2982                         if (type_specifiers & (SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY)) {
2983                                 if (type_specifiers & SPECIFIER_COMPLEX)
2984                                         errorf(pos, "_Complex specifier is invalid for _Bool");
2985                                 if (type_specifiers & SPECIFIER_IMAGINARY)
2986                                         errorf(pos, "_Imaginary specifier is invalid for _Bool");
2987                                 type_specifiers &= ~(SPECIFIER_COMPLEX|SPECIFIER_IMAGINARY);
2988                         }
2989                         atomic_type = ATOMIC_TYPE_BOOL;
2990                         break;
2991                 default: {
2992                         /* invalid specifier combination, give an error message */
2993                         if (type_specifiers == 0) {
2994                                 if (!saw_error) {
2995                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2996                                         if (!(c_mode & _CXX) && !strict_mode) {
2997                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2998                                                 atomic_type = ATOMIC_TYPE_INT;
2999                                                 break;
3000                                         } else {
3001                                                 errorf(pos, "no type specifiers given in declaration");
3002                                         }
3003                                 }
3004                         } else if (type_specifiers == SPECIFIER_COMPLEX) {
3005                                 warningf(WARN_OTHER, pos, "_Complex requires a type specifier; assuming '_Complex double'");
3006                                 atomic_type = ATOMIC_TYPE_DOUBLE;
3007                                 break;
3008                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3009                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3010                                 errorf(pos, "signed and unsigned specifiers given");
3011                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3012                                 errorf(pos, "only integer types can be signed or unsigned");
3013                         } else {
3014                                 errorf(pos, "multiple datatypes in declaration");
3015                         }
3016                         specifiers->type = type_error_type;
3017                         return;
3018                 }
3019                 }
3020
3021                 if (type_specifiers & SPECIFIER_COMPLEX) {
3022                         type = allocate_type_zero(TYPE_COMPLEX);
3023                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3024                         type = allocate_type_zero(TYPE_IMAGINARY);
3025                 } else {
3026                         type = allocate_type_zero(TYPE_ATOMIC);
3027                 }
3028                 type->atomic.akind = atomic_type;
3029                 newtype = true;
3030         } else if (type_specifiers != 0) {
3031                 errorf(&specifiers->pos, "multiple datatypes in declaration");
3032         }
3033
3034         /* FIXME: check type qualifiers here */
3035         type->base.qualifiers = qualifiers;
3036
3037         if (newtype) {
3038                 type = identify_new_type(type);
3039         } else {
3040                 type = typehash_insert(type);
3041         }
3042
3043         if (specifiers->attributes != NULL)
3044                 type = handle_type_attributes(specifiers->attributes, type);
3045         specifiers->type = type;
3046 }
3047
3048 static type_qualifiers_t parse_type_qualifiers(void)
3049 {
3050         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3051
3052         while (true) {
3053                 switch (token.kind) {
3054                 /* type qualifiers */
3055                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3056                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3057                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3058                 /* microsoft extended type modifiers */
3059                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3060                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3061                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3062                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3063                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3064
3065                 default:
3066                         return qualifiers;
3067                 }
3068         }
3069 }
3070
3071 /**
3072  * Parses an K&R identifier list
3073  */
3074 static void parse_identifier_list(scope_t *scope)
3075 {
3076         assert(token.kind == T_IDENTIFIER);
3077         do {
3078                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3079                 /* a K&R parameter has no type, yet */
3080                 eat(T_IDENTIFIER);
3081
3082                 if (scope != NULL)
3083                         append_entity(scope, entity);
3084         } while (accept(',') && token.kind == T_IDENTIFIER);
3085 }
3086
3087 static entity_t *parse_parameter(void)
3088 {
3089         declaration_specifiers_t specifiers;
3090         parse_declaration_specifiers(&specifiers);
3091
3092         entity_t *entity = parse_declarator(&specifiers,
3093                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3094         anonymous_entity = NULL;
3095         return entity;
3096 }
3097
3098 static void semantic_parameter_incomplete(const entity_t *entity)
3099 {
3100         assert(entity->kind == ENTITY_PARAMETER);
3101
3102         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3103          *             list in a function declarator that is part of a
3104          *             definition of that function shall not have
3105          *             incomplete type. */
3106         type_t *type = skip_typeref(entity->declaration.type);
3107         if (is_type_incomplete(type)) {
3108                 errorf(&entity->base.pos, "'%N' has incomplete type", entity);
3109         }
3110 }
3111
3112 static bool has_parameters(void)
3113 {
3114         /* func(void) is not a parameter */
3115         if (look_ahead(1)->kind != ')')
3116                 return true;
3117         if (token.kind == T_IDENTIFIER) {
3118                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3119                 if (entity == NULL)
3120                         return true;
3121                 if (entity->kind != ENTITY_TYPEDEF)
3122                         return true;
3123                 type_t const *const type = skip_typeref(entity->typedefe.type);
3124                 if (!is_type_void(type))
3125                         return true;
3126                 if (c_mode & _CXX) {
3127                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3128                          * is not allowed. */
3129                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3130                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3131                         /* §6.7.5.3:10  Qualification is not allowed here. */
3132                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3133                 }
3134         } else if (token.kind != T_void) {
3135                 return true;
3136         }
3137         next_token();
3138         return false;
3139 }
3140
3141 /**
3142  * Parses function type parameters (and optionally creates variable_t entities
3143  * for them in a scope)
3144  */
3145 static void parse_parameters(function_type_t *type, scope_t *scope)
3146 {
3147         add_anchor_token(')');
3148         eat('(');
3149
3150         if (token.kind == T_IDENTIFIER            &&
3151             !is_typedef_symbol(token.base.symbol) &&
3152             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3153                 type->kr_style_parameters = true;
3154                 parse_identifier_list(scope);
3155         } else if (token.kind == ')') {
3156                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3157                 if (!(c_mode & _CXX))
3158                         type->unspecified_parameters = true;
3159         } else if (has_parameters()) {
3160                 function_parameter_t **anchor = &type->parameters;
3161                 add_anchor_token(',');
3162                 do {
3163                         switch (token.kind) {
3164                         case T_DOTDOTDOT:
3165                                 eat(T_DOTDOTDOT);
3166                                 type->variadic = true;
3167                                 goto parameters_finished;
3168
3169                         case T_IDENTIFIER:
3170                         DECLARATION_START
3171                         {
3172                                 entity_t *entity = parse_parameter();
3173                                 if (entity->kind == ENTITY_TYPEDEF) {
3174                                         errorf(&entity->base.pos,
3175                                                         "typedef not allowed as function parameter");
3176                                         break;
3177                                 }
3178                                 assert(is_declaration(entity));
3179
3180                                 semantic_parameter_incomplete(entity);
3181
3182                                 function_parameter_t *const parameter =
3183                                         allocate_parameter(entity->declaration.type);
3184
3185                                 if (scope != NULL) {
3186                                         append_entity(scope, entity);
3187                                 }
3188
3189                                 *anchor = parameter;
3190                                 anchor  = &parameter->next;
3191                                 break;
3192                         }
3193
3194                         default:
3195                                 goto parameters_finished;
3196                         }
3197                 } while (accept(','));
3198 parameters_finished:
3199                 rem_anchor_token(',');
3200         }
3201
3202         rem_anchor_token(')');
3203         expect(')');
3204 }
3205
3206 typedef enum construct_type_kind_t {
3207         CONSTRUCT_POINTER = 1,
3208         CONSTRUCT_REFERENCE,
3209         CONSTRUCT_FUNCTION,
3210         CONSTRUCT_ARRAY
3211 } construct_type_kind_t;
3212
3213 typedef union construct_type_t construct_type_t;
3214
3215 typedef struct construct_type_base_t {
3216         construct_type_kind_t kind;
3217         position_t            pos;
3218         construct_type_t     *next;
3219 } construct_type_base_t;
3220
3221 typedef struct parsed_pointer_t {
3222         construct_type_base_t  base;
3223         type_qualifiers_t      type_qualifiers;
3224         variable_t            *base_variable;  /**< MS __based extension. */
3225 } parsed_pointer_t;
3226
3227 typedef struct parsed_reference_t {
3228         construct_type_base_t base;
3229 } parsed_reference_t;
3230
3231 typedef struct construct_function_type_t {
3232         construct_type_base_t  base;
3233         type_t                *function_type;
3234 } construct_function_type_t;
3235
3236 typedef struct parsed_array_t {
3237         construct_type_base_t  base;
3238         type_qualifiers_t      type_qualifiers;
3239         bool                   is_static;
3240         bool                   is_variable;
3241         expression_t          *size;
3242 } parsed_array_t;
3243
3244 union construct_type_t {
3245         construct_type_kind_t     kind;
3246         construct_type_base_t     base;
3247         parsed_pointer_t          pointer;
3248         parsed_reference_t        reference;
3249         construct_function_type_t function;
3250         parsed_array_t            array;
3251 };
3252
3253 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3254 {
3255         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3256         memset(cons, 0, size);
3257         cons->kind     = kind;
3258         cons->base.pos = *HERE;
3259         return cons;
3260 }
3261
3262 /* §6.7.5.1 */
3263 static construct_type_t *parse_pointer_declarator(void)
3264 {
3265         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3266         eat('*');
3267         cons->pointer.type_qualifiers = parse_type_qualifiers();
3268         //cons->pointer.base_variable   = base_variable;
3269
3270         return cons;
3271 }
3272
3273 /* ISO/IEC 14882:1998(E) §8.3.2 */
3274 static construct_type_t *parse_reference_declarator(void)
3275 {
3276         if (!(c_mode & _CXX))
3277                 errorf(HERE, "references are only available for C++");
3278
3279         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3280         eat('&');
3281
3282         return cons;
3283 }
3284
3285 /* §6.7.5.2 */
3286 static construct_type_t *parse_array_declarator(void)
3287 {
3288         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3289         parsed_array_t   *const array = &cons->array;
3290
3291         eat('[');
3292         add_anchor_token(']');
3293
3294         bool is_static = accept(T_static);
3295
3296         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3297
3298         if (!is_static)
3299                 is_static = accept(T_static);
3300
3301         array->type_qualifiers = type_qualifiers;
3302         array->is_static       = is_static;
3303
3304         expression_t *size = NULL;
3305         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3306                 array->is_variable = true;
3307                 eat('*');
3308         } else if (token.kind != ']') {
3309                 size = parse_assignment_expression();
3310
3311                 /* §6.7.5.2:1  Array size must have integer type */
3312                 type_t *const orig_type = size->base.type;
3313                 type_t *const type      = skip_typeref(orig_type);
3314                 if (!is_type_integer(type) && is_type_valid(type)) {
3315                         errorf(&size->base.pos,
3316                                "array size '%E' must have integer type but has type '%T'",
3317                                size, orig_type);
3318                 }
3319
3320                 array->size = size;
3321                 mark_vars_read(size, NULL);
3322         }
3323
3324         if (is_static && size == NULL)
3325                 errorf(&array->base.pos, "static array parameters require a size");
3326
3327         rem_anchor_token(']');
3328         expect(']');
3329         return cons;
3330 }
3331
3332 /* §6.7.5.3 */
3333 static construct_type_t *parse_function_declarator(scope_t *scope)
3334 {
3335         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3336
3337         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3338         function_type_t *ftype = &type->function;
3339
3340         ftype->linkage            = current_linkage;
3341         ftype->calling_convention = CC_DEFAULT;
3342
3343         parse_parameters(ftype, scope);
3344
3345         cons->function.function_type = type;
3346
3347         return cons;
3348 }
3349
3350 typedef struct parse_declarator_env_t {
3351         bool              may_be_abstract : 1;
3352         bool              must_be_abstract : 1;
3353         decl_modifiers_t  modifiers;
3354         symbol_t         *symbol;
3355         position_t        pos;
3356         scope_t           parameters;
3357         attribute_t      *attributes;
3358 } parse_declarator_env_t;
3359
3360 /* §6.7.5 */
3361 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3362 {
3363         /* construct a single linked list of construct_type_t's which describe
3364          * how to construct the final declarator type */
3365         construct_type_t  *first      = NULL;
3366         construct_type_t **anchor     = &first;
3367
3368         env->attributes = parse_attributes(env->attributes);
3369
3370         for (;;) {
3371                 construct_type_t *type;
3372                 //variable_t       *based = NULL; /* MS __based extension */
3373                 switch (token.kind) {
3374                         case '&':
3375                                 type = parse_reference_declarator();
3376                                 break;
3377
3378                         case T__based: {
3379                                 panic("based not supported anymore");
3380                                 /* FALLTHROUGH */
3381                         }
3382
3383                         case '*':
3384                                 type = parse_pointer_declarator();
3385                                 break;
3386
3387                         default:
3388                                 goto ptr_operator_end;
3389                 }
3390
3391                 *anchor = type;
3392                 anchor  = &type->base.next;
3393
3394                 /* TODO: find out if this is correct */
3395                 env->attributes = parse_attributes(env->attributes);
3396         }
3397
3398 ptr_operator_end: ;
3399         construct_type_t *inner_types = NULL;
3400
3401         switch (token.kind) {
3402         case T_IDENTIFIER:
3403                 if (env->must_be_abstract) {
3404                         errorf(HERE, "no identifier expected in typename");
3405                 } else {
3406                         env->symbol = token.base.symbol;
3407                         env->pos    = *HERE;
3408                 }
3409                 eat(T_IDENTIFIER);
3410                 break;
3411
3412         case '(': {
3413                 /* Parenthesized declarator or function declarator? */
3414                 token_t const *const la1 = look_ahead(1);
3415                 switch (la1->kind) {
3416                         case T_IDENTIFIER:
3417                                 if (is_typedef_symbol(la1->base.symbol)) {
3418                         case ')':
3419                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3420                                          * interpreted as ``function with no parameter specification'', rather
3421                                          * than redundant parentheses around the omitted identifier. */
3422                         default:
3423                                         /* Function declarator. */
3424                                         if (!env->may_be_abstract) {
3425                                                 errorf(HERE, "function declarator must have a name");
3426                                         }
3427                                 } else {
3428                         case '&':
3429                         case '(':
3430                         case '*':
3431                         case '[':
3432                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3433                                         /* Paranthesized declarator. */
3434                                         eat('(');
3435                                         add_anchor_token(')');
3436                                         inner_types = parse_inner_declarator(env);
3437                                         if (inner_types != NULL) {
3438                                                 /* All later declarators only modify the return type */
3439                                                 env->must_be_abstract = true;
3440                                         }
3441                                         rem_anchor_token(')');
3442                                         expect(')');
3443                                 }
3444                                 break;
3445                 }
3446                 break;
3447         }
3448
3449         default:
3450                 if (env->may_be_abstract)
3451                         break;
3452                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3453                 eat_until_anchor();
3454                 return NULL;
3455         }
3456
3457         construct_type_t **const p = anchor;
3458
3459         for (;;) {
3460                 construct_type_t *type;
3461                 switch (token.kind) {
3462                 case '(': {
3463                         scope_t *scope = NULL;
3464                         if (!env->must_be_abstract) {
3465                                 scope = &env->parameters;
3466                         }
3467
3468                         type = parse_function_declarator(scope);
3469                         break;
3470                 }
3471                 case '[':
3472                         type = parse_array_declarator();
3473                         break;
3474                 default:
3475                         goto declarator_finished;
3476                 }
3477
3478                 /* insert in the middle of the list (at p) */
3479                 type->base.next = *p;
3480                 *p              = type;
3481                 if (anchor == p)
3482                         anchor = &type->base.next;
3483         }
3484
3485 declarator_finished:
3486         /* append inner_types at the end of the list, we don't to set anchor anymore
3487          * as it's not needed anymore */
3488         *anchor = inner_types;
3489
3490         return first;
3491 }
3492
3493 static type_t *construct_declarator_type(construct_type_t *construct_list,
3494                                          type_t *type)
3495 {
3496         construct_type_t *iter = construct_list;
3497         for (; iter != NULL; iter = iter->base.next) {
3498                 position_t const* const pos = &iter->base.pos;
3499                 switch (iter->kind) {
3500                 case CONSTRUCT_FUNCTION: {
3501                         construct_function_type_t *function      = &iter->function;
3502                         type_t                    *function_type = function->function_type;
3503
3504                         function_type->function.return_type = type;
3505
3506                         type_t *skipped_return_type = skip_typeref(type);
3507                         /* §6.7.5.3:1 */
3508                         if (is_type_function(skipped_return_type)) {
3509                                 errorf(pos, "function returning function is not allowed");
3510                         } else if (is_type_array(skipped_return_type)) {
3511                                 errorf(pos, "function returning array is not allowed");
3512                         } else {
3513                                 if (skipped_return_type->base.qualifiers != 0) {
3514                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3515                                 }
3516                         }
3517
3518                         /* The function type was constructed earlier.  Freeing it here will
3519                          * destroy other types. */
3520                         type = typehash_insert(function_type);
3521                         continue;
3522                 }
3523
3524                 case CONSTRUCT_POINTER: {
3525                         if (is_type_reference(skip_typeref(type)))
3526                                 errorf(pos, "cannot declare a pointer to reference");
3527
3528                         parsed_pointer_t *pointer = &iter->pointer;
3529                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3530                         continue;
3531                 }
3532
3533                 case CONSTRUCT_REFERENCE:
3534                         if (is_type_reference(skip_typeref(type)))
3535                                 errorf(pos, "cannot declare a reference to reference");
3536
3537                         type = make_reference_type(type);
3538                         continue;
3539
3540                 case CONSTRUCT_ARRAY: {
3541                         if (is_type_reference(skip_typeref(type)))
3542                                 errorf(pos, "cannot declare an array of references");
3543
3544                         parsed_array_t *array      = &iter->array;
3545                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3546
3547                         expression_t *size_expression = array->size;
3548                         if (size_expression != NULL) {
3549                                 size_expression
3550                                         = create_implicit_cast(size_expression, type_size_t);
3551                         }
3552
3553                         array_type->base.qualifiers       = array->type_qualifiers;
3554                         array_type->array.element_type    = type;
3555                         array_type->array.is_static       = array->is_static;
3556                         array_type->array.is_variable     = array->is_variable;
3557                         array_type->array.size_expression = size_expression;
3558
3559                         if (size_expression != NULL) {
3560                                 switch (is_constant_expression(size_expression)) {
3561                                 case EXPR_CLASS_CONSTANT: {
3562                                         long const size = fold_constant_to_int(size_expression);
3563                                         array_type->array.size          = size;
3564                                         array_type->array.size_constant = true;
3565                                         /* §6.7.5.2:1  If the expression is a constant expression,
3566                                          * it shall have a value greater than zero. */
3567                                         if (size < 0) {
3568                                                 errorf(&size_expression->base.pos,
3569                                                            "size of array must be greater than zero");
3570                                         } else if (size == 0 && !GNU_MODE) {
3571                                                 errorf(&size_expression->base.pos,
3572                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3573                                         }
3574                                         break;
3575                                 }
3576
3577                                 case EXPR_CLASS_VARIABLE:
3578                                         array_type->array.is_vla = true;
3579                                         break;
3580
3581                                 case EXPR_CLASS_ERROR:
3582                                         break;
3583                                 }
3584                         }
3585
3586                         type_t *skipped_type = skip_typeref(type);
3587                         /* §6.7.5.2:1 */
3588                         if (is_type_incomplete(skipped_type)) {
3589                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3590                         } else if (is_type_function(skipped_type)) {
3591                                 errorf(pos, "array of functions is not allowed");
3592                         }
3593                         type = identify_new_type(array_type);
3594                         continue;
3595                 }
3596                 }
3597                 internal_errorf(pos, "invalid type construction found");
3598         }
3599
3600         return type;
3601 }
3602
3603 static type_t *automatic_type_conversion(type_t *orig_type);
3604
3605 static type_t *semantic_parameter(const position_t *pos, type_t *type,
3606                                   const declaration_specifiers_t *specifiers,
3607                                   entity_t const *const param)
3608 {
3609         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3610          *             shall be adjusted to ``qualified pointer to type'',
3611          *             [...]
3612          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3613          *             type'' shall be adjusted to ``pointer to function
3614          *             returning type'', as in 6.3.2.1. */
3615         type = automatic_type_conversion(type);
3616
3617         if (specifiers->is_inline && is_type_valid(type)) {
3618                 errorf(pos, "'%N' declared 'inline'", param);
3619         }
3620
3621         /* §6.9.1:6  The declarations in the declaration list shall contain
3622          *           no storage-class specifier other than register and no
3623          *           initializations. */
3624         if (specifiers->thread_local || (
3625                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3626                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3627            ) {
3628                 errorf(pos, "invalid storage class for '%N'", param);
3629         }
3630
3631         /* delay test for incomplete type, because we might have (void)
3632          * which is legal but incomplete... */
3633
3634         return type;
3635 }
3636
3637 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3638                                   declarator_flags_t flags)
3639 {
3640         parse_declarator_env_t env;
3641         memset(&env, 0, sizeof(env));
3642         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3643
3644         construct_type_t *construct_type = parse_inner_declarator(&env);
3645         type_t           *orig_type      =
3646                 construct_declarator_type(construct_type, specifiers->type);
3647         type_t           *type           = skip_typeref(orig_type);
3648
3649         if (construct_type != NULL) {
3650                 obstack_free(&temp_obst, construct_type);
3651         }
3652
3653         attribute_t *attributes = parse_attributes(env.attributes);
3654         /* append (shared) specifier attribute behind attributes of this
3655          * declarator */
3656         attribute_t **anchor = &attributes;
3657         while (*anchor != NULL)
3658                 anchor = &(*anchor)->next;
3659         *anchor = specifiers->attributes;
3660
3661         entity_t *entity;
3662         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3663                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.pos);
3664                 entity->typedefe.type = orig_type;
3665
3666                 if (anonymous_entity != NULL) {
3667                         if (is_type_compound(type)) {
3668                                 assert(anonymous_entity->compound.alias == NULL);
3669                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3670                                        anonymous_entity->kind == ENTITY_UNION);
3671                                 anonymous_entity->compound.alias = entity;
3672                                 anonymous_entity = NULL;
3673                         } else if (is_type_enum(type)) {
3674                                 assert(anonymous_entity->enume.alias == NULL);
3675                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3676                                 anonymous_entity->enume.alias = entity;
3677                                 anonymous_entity = NULL;
3678                         }
3679                 }
3680         } else {
3681                 /* create a declaration type entity */
3682                 position_t const *const pos = env.symbol ? &env.pos : &specifiers->pos;
3683                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3684                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3685
3686                         if (env.symbol != NULL) {
3687                                 if (specifiers->is_inline && is_type_valid(type)) {
3688                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3689                                 }
3690
3691                                 if (specifiers->thread_local ||
3692                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3693                                         errorf(&env.pos, "'%N' must have no storage class", entity);
3694                                 }
3695                         }
3696                 } else if (flags & DECL_IS_PARAMETER) {
3697                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3698                         orig_type = semantic_parameter(&env.pos, orig_type, specifiers, entity);
3699                 } else if (is_type_function(type)) {
3700                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3701                         entity->function.is_inline      = specifiers->is_inline;
3702                         entity->function.elf_visibility = default_visibility;
3703                         entity->function.parameters     = env.parameters;
3704
3705                         if (env.symbol != NULL) {
3706                                 /* this needs fixes for C++ */
3707                                 bool in_function_scope = current_function != NULL;
3708
3709                                 if (specifiers->thread_local || (
3710                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3711                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3712                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3713                                                 )) {
3714                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3715                                 }
3716                         }
3717                 } else {
3718                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3719                         entity->variable.elf_visibility = default_visibility;
3720                         entity->variable.thread_local   = specifiers->thread_local;
3721
3722                         if (env.symbol != NULL) {
3723                                 if (specifiers->is_inline && is_type_valid(type)) {
3724                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3725                                 }
3726
3727                                 bool invalid_storage_class = false;
3728                                 if (current_scope == file_scope) {
3729                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3730                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3731                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3732                                                 invalid_storage_class = true;
3733                                         }
3734                                 } else {
3735                                         if (specifiers->thread_local &&
3736                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3737                                                 invalid_storage_class = true;
3738                                         }
3739                                 }
3740                                 if (invalid_storage_class) {
3741                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3742                                 }
3743                         }
3744                 }
3745
3746                 entity->declaration.type       = orig_type;
3747                 entity->declaration.alignment  = get_type_alignment(orig_type);
3748                 entity->declaration.modifiers  = env.modifiers;
3749                 entity->declaration.attributes = attributes;
3750
3751                 storage_class_t storage_class = specifiers->storage_class;
3752                 entity->declaration.declared_storage_class = storage_class;
3753
3754                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3755                         storage_class = STORAGE_CLASS_AUTO;
3756                 entity->declaration.storage_class = storage_class;
3757         }
3758
3759         if (attributes != NULL) {
3760                 handle_entity_attributes(attributes, entity);
3761         }
3762
3763         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3764                 adapt_special_functions(&entity->function);
3765         }
3766
3767         return entity;
3768 }
3769
3770 static type_t *parse_abstract_declarator(type_t *base_type)
3771 {
3772         parse_declarator_env_t env;
3773         memset(&env, 0, sizeof(env));
3774         env.may_be_abstract = true;
3775         env.must_be_abstract = true;
3776
3777         construct_type_t *construct_type = parse_inner_declarator(&env);
3778
3779         type_t *result = construct_declarator_type(construct_type, base_type);
3780         if (construct_type != NULL) {
3781                 obstack_free(&temp_obst, construct_type);
3782         }
3783         result = handle_type_attributes(env.attributes, result);
3784
3785         return result;
3786 }
3787
3788 /**
3789  * Check if the declaration of main is suspicious.  main should be a
3790  * function with external linkage, returning int, taking either zero
3791  * arguments, two, or three arguments of appropriate types, ie.
3792  *
3793  * int main([ int argc, char **argv [, char **env ] ]).
3794  *
3795  * @param decl    the declaration to check
3796  * @param type    the function type of the declaration
3797  */
3798 static void check_main(const entity_t *entity)
3799 {
3800         const position_t *pos = &entity->base.pos;
3801         if (entity->kind != ENTITY_FUNCTION) {
3802                 warningf(WARN_MAIN, pos, "'main' is not a function");
3803                 return;
3804         }
3805
3806         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3807                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3808         }
3809
3810         type_t *type = skip_typeref(entity->declaration.type);
3811         assert(is_type_function(type));
3812
3813         function_type_t const *const func_type = &type->function;
3814         type_t                *const ret_type  = func_type->return_type;
3815         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3816                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3817         }
3818         const function_parameter_t *parm = func_type->parameters;
3819         if (parm != NULL) {
3820                 type_t *const first_type        = skip_typeref(parm->type);
3821                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3822                 if (!types_compatible(first_type_unqual, type_int)) {
3823                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3824                 }
3825                 parm = parm->next;
3826                 if (parm != NULL) {
3827                         type_t *const second_type = skip_typeref(parm->type);
3828                         type_t *const second_type_unqual
3829                                 = get_unqualified_type(second_type);
3830                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3831                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3832                         }
3833                         parm = parm->next;
3834                         if (parm != NULL) {
3835                                 type_t *const third_type = skip_typeref(parm->type);
3836                                 type_t *const third_type_unqual
3837                                         = get_unqualified_type(third_type);
3838                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3839                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3840                                 }
3841                                 parm = parm->next;
3842                                 if (parm != NULL)
3843                                         goto warn_arg_count;
3844                         }
3845                 } else {
3846 warn_arg_count:
3847                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3848                 }
3849         }
3850 }
3851
3852 static void error_redefined_as_different_kind(const position_t *pos,
3853                 const entity_t *old, entity_kind_t new_kind)
3854 {
3855         char       const *const what = get_entity_kind_name(new_kind);
3856         position_t const *const ppos = &old->base.pos;
3857         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3858 }
3859
3860 static bool is_entity_valid(entity_t *const ent)
3861 {
3862         if (is_declaration(ent)) {
3863                 return is_type_valid(skip_typeref(ent->declaration.type));
3864         } else if (ent->kind == ENTITY_TYPEDEF) {
3865                 return is_type_valid(skip_typeref(ent->typedefe.type));
3866         }
3867         return true;
3868 }
3869
3870 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3871 {
3872         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3873                 if (attributes_equal(tattr, attr))
3874                         return true;
3875         }
3876         return false;
3877 }
3878
3879 /**
3880  * Tests whether new_list contains any attributes not included in old_list
3881  */
3882 static bool has_new_attributes(const attribute_t *old_list,
3883                                const attribute_t *new_list)
3884 {
3885         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3886                 if (!contains_attribute(old_list, attr))
3887                         return true;
3888         }
3889         return false;
3890 }
3891
3892 /**
3893  * Merge in attributes from an attribute list (probably from a previous
3894  * declaration with the same name). Warning: destroys the old structure
3895  * of the attribute list - don't reuse attributes after this call.
3896  */
3897 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3898 {
3899         attribute_t *next;
3900         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3901                 next = attr->next;
3902                 if (contains_attribute(decl->attributes, attr))
3903                         continue;
3904
3905                 /* move attribute to new declarations attributes list */
3906                 attr->next       = decl->attributes;
3907                 decl->attributes = attr;
3908         }
3909 }
3910
3911 static bool is_main(entity_t*);
3912
3913 /**
3914  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3915  * for various problems that occur for multiple definitions
3916  */
3917 entity_t *record_entity(entity_t *entity, const bool is_definition)
3918 {
3919         const symbol_t *const symbol  = entity->base.symbol;
3920         const namespace_tag_t namespc = (namespace_tag_t)entity->base.namespc;
3921         const position_t     *pos     = &entity->base.pos;
3922
3923         /* can happen in error cases */
3924         if (symbol == NULL)
3925                 return entity;
3926
3927         assert(!entity->base.parent_scope);
3928         assert(current_scope);
3929         entity->base.parent_scope = current_scope;
3930
3931         entity_t *const previous_entity = get_entity(symbol, namespc);
3932         /* pushing the same entity twice will break the stack structure */
3933         assert(previous_entity != entity);
3934
3935         if (entity->kind == ENTITY_FUNCTION) {
3936                 type_t *const orig_type = entity->declaration.type;
3937                 type_t *const type      = skip_typeref(orig_type);
3938
3939                 assert(is_type_function(type));
3940                 if (type->function.unspecified_parameters &&
3941                     previous_entity == NULL               &&
3942                     !entity->declaration.implicit) {
3943                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3944                 }
3945
3946                 if (is_main(entity)) {
3947                         check_main(entity);
3948                 }
3949         }
3950
3951         if (is_declaration(entity)                                    &&
3952             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3953             current_scope != file_scope                               &&
3954             !entity->declaration.implicit) {
3955                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3956         }
3957
3958         if (previous_entity != NULL) {
3959                 position_t const *const ppos = &previous_entity->base.pos;
3960
3961                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3962                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3963                         assert(previous_entity->kind == ENTITY_PARAMETER);
3964                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3965                         goto finish;
3966                 }
3967
3968                 if (previous_entity->base.parent_scope == current_scope) {
3969                         if (previous_entity->kind != entity->kind) {
3970                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3971                                         error_redefined_as_different_kind(pos, previous_entity,
3972                                                         entity->kind);
3973                                 }
3974                                 goto finish;
3975                         }
3976                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3977                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3978                                 goto finish;
3979                         }
3980                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3981                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3982                                 type_t *const prev_type
3983                                         = skip_typeref(previous_entity->typedefe.type);
3984                                 if (c_mode & _CXX) {
3985                                         /* C++ allows double typedef if they are identical
3986                                          * (after skipping typedefs) */
3987                                         if (type == prev_type)
3988                                                 goto finish;
3989                                 } else {
3990                                         /* GCC extension: redef in system headers is allowed */
3991                                         if ((pos->is_system_header || ppos->is_system_header) &&
3992                                             types_compatible(type, prev_type))
3993                                                 goto finish;
3994                                 }
3995                                 errorf(pos, "redefinition of '%N' (declared %P)",
3996                                        entity, ppos);
3997                                 goto finish;
3998                         }
3999
4000                         /* at this point we should have only VARIABLES or FUNCTIONS */
4001                         assert(is_declaration(previous_entity) && is_declaration(entity));
4002
4003                         declaration_t *const prev_decl = &previous_entity->declaration;
4004                         declaration_t *const decl      = &entity->declaration;
4005
4006                         /* can happen for K&R style declarations */
4007                         if (prev_decl->type       == NULL             &&
4008                                         previous_entity->kind == ENTITY_PARAMETER &&
4009                                         entity->kind          == ENTITY_PARAMETER) {
4010                                 prev_decl->type                   = decl->type;
4011                                 prev_decl->storage_class          = decl->storage_class;
4012                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4013                                 prev_decl->modifiers              = decl->modifiers;
4014                                 return previous_entity;
4015                         }
4016
4017                         type_t *const type      = skip_typeref(decl->type);
4018                         type_t *const prev_type = skip_typeref(prev_decl->type);
4019
4020                         if (!types_compatible(type, prev_type)) {
4021                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4022                         } else {
4023                                 unsigned old_storage_class = prev_decl->storage_class;
4024
4025                                 if (is_definition                     &&
4026                                                 !prev_decl->used                  &&
4027                                                 !(prev_decl->modifiers & DM_USED) &&
4028                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4029                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4030                                 }
4031
4032                                 storage_class_t new_storage_class = decl->storage_class;
4033
4034                                 /* pretend no storage class means extern for function
4035                                  * declarations (except if the previous declaration is neither
4036                                  * none nor extern) */
4037                                 if (entity->kind == ENTITY_FUNCTION) {
4038                                         /* the previous declaration could have unspecified parameters or
4039                                          * be a typedef, so use the new type */
4040                                         if (prev_type->function.unspecified_parameters || is_definition)
4041                                                 prev_decl->type = type;
4042
4043                                         switch (old_storage_class) {
4044                                                 case STORAGE_CLASS_NONE:
4045                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4046                                                         /* FALLTHROUGH */
4047
4048                                                 case STORAGE_CLASS_EXTERN:
4049                                                         if (is_definition) {
4050                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4051                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4052                                                                 }
4053                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4054                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4055                                                         }
4056                                                         break;
4057
4058                                                 default:
4059                                                         break;
4060                                         }
4061                                 } else if (is_type_incomplete(prev_type)) {
4062                                         prev_decl->type = type;
4063                                 }
4064
4065                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4066                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4067
4068 warn_redundant_declaration: ;
4069                                         bool has_new_attrs
4070                                                 = has_new_attributes(prev_decl->attributes,
4071                                                                      decl->attributes);
4072                                         if (has_new_attrs) {
4073                                                 merge_in_attributes(decl, prev_decl->attributes);
4074                                         } else if (!is_definition && is_type_valid(prev_type)) {
4075                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4076                                         }
4077                                 } else if (current_function == NULL) {
4078                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4079                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4080                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4081                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4082                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4083                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4084                                         } else {
4085                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4086                                                 if (c_mode & _CXX)
4087                                                         goto error_redeclaration;
4088                                                 goto warn_redundant_declaration;
4089                                         }
4090                                 } else if (is_type_valid(prev_type)) {
4091                                         if (old_storage_class == new_storage_class) {
4092 error_redeclaration:
4093                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4094                                         } else {
4095                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4096                                         }
4097                                 }
4098                         }
4099
4100                         prev_decl->modifiers |= decl->modifiers;
4101                         if (entity->kind == ENTITY_FUNCTION) {
4102                                 previous_entity->function.is_inline |= entity->function.is_inline;
4103                         }
4104                         return previous_entity;
4105                 }
4106
4107                 warning_t why;
4108                 if (is_warn_on(why = WARN_SHADOW) ||
4109                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4110                         char const *const what = get_entity_kind_name(previous_entity->kind);
4111                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4112                 }
4113         }
4114
4115         if (entity->kind == ENTITY_FUNCTION) {
4116                 if (is_definition &&
4117                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4118                                 !is_main(entity)) {
4119                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4120                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4121                         } else {
4122                                 goto warn_missing_declaration;
4123                         }
4124                 }
4125         } else if (entity->kind == ENTITY_VARIABLE) {
4126                 if (current_scope                     == file_scope &&
4127                     entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4128                     !entity->declaration.implicit) {
4129 warn_missing_declaration:
4130                         if (is_type_valid(skip_typeref(entity->declaration.type)))
4131                                 warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4132                 }
4133         }
4134
4135 finish:
4136         environment_push(entity);
4137         append_entity(current_scope, entity);
4138
4139         return entity;
4140 }
4141
4142 static void parser_error_multiple_definition(entity_t *entity,
4143                                              const position_t *pos)
4144 {
4145         errorf(pos, "redefinition of '%N' (declared %P)", entity, &entity->base.pos);
4146 }
4147
4148 static bool is_declaration_specifier(token_t const *const tk)
4149 {
4150         switch (tk->kind) {
4151                 DECLARATION_START
4152                         return true;
4153                 case T_IDENTIFIER:
4154                         return is_typedef_symbol(tk->base.symbol);
4155
4156                 default:
4157                         return false;
4158         }
4159 }
4160
4161 static void parse_init_declarator_rest(entity_t *entity)
4162 {
4163         type_t *orig_type = type_error_type;
4164
4165         if (entity->base.kind == ENTITY_TYPEDEF) {
4166                 position_t const *const pos = &entity->base.pos;
4167                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4168         } else {
4169                 assert(is_declaration(entity));
4170                 orig_type = entity->declaration.type;
4171         }
4172
4173         type_t *type = skip_typeref(orig_type);
4174
4175         if (entity->kind == ENTITY_VARIABLE
4176                         && entity->variable.initializer != NULL) {
4177                 parser_error_multiple_definition(entity, HERE);
4178         }
4179         eat('=');
4180
4181         declaration_t *const declaration = &entity->declaration;
4182         bool must_be_constant = false;
4183         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4184             entity->base.parent_scope  == file_scope) {
4185                 must_be_constant = true;
4186         }
4187
4188         if (is_type_function(type)) {
4189                 position_t const *const pos = &entity->base.pos;
4190                 errorf(pos, "'%N' is initialized like a variable", entity);
4191                 orig_type = type_error_type;
4192         }
4193
4194         parse_initializer_env_t env;
4195         env.type             = orig_type;
4196         env.must_be_constant = must_be_constant;
4197         env.entity           = entity;
4198
4199         initializer_t *initializer = parse_initializer(&env);
4200
4201         if (entity->kind == ENTITY_VARIABLE) {
4202                 /* §6.7.5:22  array initializers for arrays with unknown size
4203                  * determine the array type size */
4204                 declaration->type            = env.type;
4205                 entity->variable.initializer = initializer;
4206         }
4207 }
4208
4209 /* parse rest of a declaration without any declarator */
4210 static void parse_anonymous_declaration_rest(
4211                 const declaration_specifiers_t *specifiers)
4212 {
4213         eat(';');
4214         anonymous_entity = NULL;
4215
4216         position_t const *const pos = &specifiers->pos;
4217         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4218                         specifiers->thread_local) {
4219                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4220         }
4221
4222         type_t *type = specifiers->type;
4223         switch (type->kind) {
4224                 case TYPE_COMPOUND_STRUCT:
4225                 case TYPE_COMPOUND_UNION: {
4226                         if (type->compound.compound->base.symbol == NULL) {
4227                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4228                         }
4229                         break;
4230                 }
4231
4232                 case TYPE_ENUM:
4233                         break;
4234
4235                 default:
4236                         warningf(WARN_OTHER, pos, "empty declaration");
4237                         break;
4238         }
4239 }
4240
4241 static void check_variable_type_complete(entity_t *ent)
4242 {
4243         if (ent->kind != ENTITY_VARIABLE)
4244                 return;
4245
4246         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4247          *         type for the object shall be complete [...] */
4248         declaration_t *decl = &ent->declaration;
4249         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4250                         decl->storage_class == STORAGE_CLASS_STATIC)
4251                 return;
4252
4253         type_t *const type = skip_typeref(decl->type);
4254         if (!is_type_incomplete(type))
4255                 return;
4256
4257         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4258          * are given length one. */
4259         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4260                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4261                 return;
4262         }
4263
4264         errorf(&ent->base.pos, "variable '%#N' has incomplete type", ent);
4265 }
4266
4267
4268 static void parse_declaration_rest(entity_t *ndeclaration,
4269                 const declaration_specifiers_t *specifiers,
4270                 parsed_declaration_func         finished_declaration,
4271                 declarator_flags_t              flags)
4272 {
4273         add_anchor_token(';');
4274         add_anchor_token(',');
4275         while (true) {
4276                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4277
4278                 if (token.kind == '=') {
4279                         parse_init_declarator_rest(entity);
4280                 } else if (entity->kind == ENTITY_VARIABLE) {
4281                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4282                          * [...] where the extern specifier is explicitly used. */
4283                         declaration_t *decl = &entity->declaration;
4284                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4285                             is_type_reference(skip_typeref(decl->type))) {
4286                                 position_t const *const pos = &entity->base.pos;
4287                                 errorf(pos, "reference '%#N' must be initialized", entity);
4288                         }
4289                 }
4290
4291                 check_variable_type_complete(entity);
4292
4293                 if (!accept(','))
4294                         break;
4295
4296                 add_anchor_token('=');
4297                 ndeclaration = parse_declarator(specifiers, flags);
4298                 rem_anchor_token('=');
4299         }
4300         rem_anchor_token(',');
4301         rem_anchor_token(';');
4302         expect(';');
4303
4304         anonymous_entity = NULL;
4305 }
4306
4307 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4308 {
4309         symbol_t *symbol = entity->base.symbol;
4310         if (symbol == NULL)
4311                 return entity;
4312
4313         assert(entity->base.namespc == NAMESPACE_NORMAL);
4314         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4315         if (previous_entity == NULL
4316                         || previous_entity->base.parent_scope != current_scope) {
4317                 errorf(&entity->base.pos, "expected declaration of a function parameter, found '%Y'",
4318                        symbol);
4319                 return entity;
4320         }
4321
4322         if (is_definition) {
4323                 errorf(HERE, "'%N' is initialised", entity);
4324         }
4325
4326         return record_entity(entity, false);
4327 }
4328
4329 static void parse_declaration(parsed_declaration_func finished_declaration,
4330                               declarator_flags_t      flags)
4331 {
4332         add_anchor_token(';');
4333         declaration_specifiers_t specifiers;
4334         parse_declaration_specifiers(&specifiers);
4335         rem_anchor_token(';');
4336
4337         if (token.kind == ';') {
4338                 parse_anonymous_declaration_rest(&specifiers);
4339         } else {
4340                 entity_t *entity = parse_declarator(&specifiers, flags);
4341                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4342         }
4343 }
4344
4345 /* §6.5.2.2:6 */
4346 static type_t *get_default_promoted_type(type_t *orig_type)
4347 {
4348         type_t *result = orig_type;
4349
4350         type_t *type = skip_typeref(orig_type);
4351         if (is_type_integer(type)) {
4352                 result = promote_integer(type);
4353         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4354                 result = type_double;
4355         }
4356
4357         return result;
4358 }
4359
4360 static void parse_kr_declaration_list(entity_t *entity)
4361 {
4362         if (entity->kind != ENTITY_FUNCTION)
4363                 return;
4364
4365         type_t *type = skip_typeref(entity->declaration.type);
4366         assert(is_type_function(type));
4367         if (!type->function.kr_style_parameters)
4368                 return;
4369
4370         add_anchor_token('{');
4371
4372         PUSH_SCOPE(&entity->function.parameters);
4373
4374         entity_t *parameter = entity->function.parameters.entities;
4375         for ( ; parameter != NULL; parameter = parameter->base.next) {
4376                 assert(parameter->base.parent_scope == NULL);
4377                 parameter->base.parent_scope = current_scope;
4378                 environment_push(parameter);
4379         }
4380
4381         /* parse declaration list */
4382         for (;;) {
4383                 switch (token.kind) {
4384                         DECLARATION_START
4385                         /* This covers symbols, which are no type, too, and results in
4386                          * better error messages.  The typical cases are misspelled type
4387                          * names and missing includes. */
4388                         case T_IDENTIFIER:
4389                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4390                                 break;
4391                         default:
4392                                 goto decl_list_end;
4393                 }
4394         }
4395 decl_list_end:
4396
4397         POP_SCOPE();
4398
4399         /* update function type */
4400         type_t *new_type = duplicate_type(type);
4401
4402         function_parameter_t  *parameters = NULL;
4403         function_parameter_t **anchor     = &parameters;
4404
4405         /* did we have an earlier prototype? */
4406         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4407         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4408                 proto_type = NULL;
4409
4410         function_parameter_t *proto_parameter = NULL;
4411         if (proto_type != NULL) {
4412                 type_t *proto_type_type = proto_type->declaration.type;
4413                 proto_parameter         = proto_type_type->function.parameters;
4414                 /* If a K&R function definition has a variadic prototype earlier, then
4415                  * make the function definition variadic, too. This should conform to
4416                  * §6.7.5.3:15 and §6.9.1:8. */
4417                 new_type->function.variadic = proto_type_type->function.variadic;
4418         } else {
4419                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4420                  * prototype */
4421                 new_type->function.unspecified_parameters = true;
4422         }
4423
4424         bool need_incompatible_warning = false;
4425         parameter = entity->function.parameters.entities;
4426         for (; parameter != NULL; parameter = parameter->base.next,
4427                         proto_parameter =
4428                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4429                 if (parameter->kind != ENTITY_PARAMETER)
4430                         continue;
4431
4432                 type_t *parameter_type = parameter->declaration.type;
4433                 if (parameter_type == NULL) {
4434                         position_t const* const pos = &parameter->base.pos;
4435                         if (strict_mode) {
4436                                 errorf(pos, "no type specified for function '%N'", parameter);
4437                                 parameter_type = type_error_type;
4438                         } else {
4439                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4440                                 parameter_type = type_int;
4441                         }
4442                         parameter->declaration.type = parameter_type;
4443                 }
4444
4445                 semantic_parameter_incomplete(parameter);
4446
4447                 /* we need the default promoted types for the function type */
4448                 type_t *not_promoted = parameter_type;
4449                 parameter_type       = get_default_promoted_type(parameter_type);
4450
4451                 /* gcc special: if the type of the prototype matches the unpromoted
4452                  * type don't promote */
4453                 if (!strict_mode && proto_parameter != NULL) {
4454                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4455                         type_t *promo_skip   = skip_typeref(parameter_type);
4456                         type_t *param_skip   = skip_typeref(not_promoted);
4457                         if (!types_compatible(proto_p_type, promo_skip)
4458                                 && types_compatible(proto_p_type, param_skip)) {
4459                                 /* don't promote */
4460                                 need_incompatible_warning = true;
4461                                 parameter_type = not_promoted;
4462                         }
4463                 }
4464                 function_parameter_t *const function_parameter
4465                         = allocate_parameter(parameter_type);
4466
4467                 *anchor = function_parameter;
4468                 anchor  = &function_parameter->next;
4469         }
4470
4471         new_type->function.parameters = parameters;
4472         new_type = identify_new_type(new_type);
4473
4474         if (need_incompatible_warning) {
4475                 symbol_t   const *const sym  = entity->base.symbol;
4476                 position_t const *const pos  = &entity->base.pos;
4477                 position_t const *const ppos = &proto_type->base.pos;
4478                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4479         }
4480         entity->declaration.type = new_type;
4481
4482         rem_anchor_token('{');
4483 }
4484
4485 static bool first_err = true;
4486
4487 /**
4488  * When called with first_err set, prints the name of the current function,
4489  * else does noting.
4490  */
4491 static void print_in_function(void)
4492 {
4493         if (first_err) {
4494                 first_err = false;
4495                 char const *const file = current_function->base.base.pos.input_name;
4496                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4497         }
4498 }
4499
4500 /**
4501  * Check if all labels are defined in the current function.
4502  * Check if all labels are used in the current function.
4503  */
4504 static void check_labels(void)
4505 {
4506         for (const goto_statement_t *goto_statement = goto_first;
4507             goto_statement != NULL;
4508             goto_statement = goto_statement->next) {
4509                 label_t *label = goto_statement->label;
4510                 if (label->base.pos.input_name == NULL) {
4511                         print_in_function();
4512                         position_t const *const pos = &goto_statement->base.pos;
4513                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4514                  }
4515         }
4516
4517         if (is_warn_on(WARN_UNUSED_LABEL)) {
4518                 for (const label_statement_t *label_statement = label_first;
4519                          label_statement != NULL;
4520                          label_statement = label_statement->next) {
4521                         label_t *label = label_statement->label;
4522
4523                         if (! label->used) {
4524                                 print_in_function();
4525                                 position_t const *const pos = &label_statement->base.pos;
4526                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4527                         }
4528                 }
4529         }
4530 }
4531
4532 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4533 {
4534         entity_t const *const end = last != NULL ? last->base.next : NULL;
4535         for (; entity != end; entity = entity->base.next) {
4536                 if (!is_declaration(entity))
4537                         continue;
4538
4539                 declaration_t *declaration = &entity->declaration;
4540                 if (declaration->implicit)
4541                         continue;
4542
4543                 if (!declaration->used) {
4544                         print_in_function();
4545                         warningf(why, &entity->base.pos, "'%N' is unused", entity);
4546                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4547                         print_in_function();
4548                         warningf(why, &entity->base.pos, "'%N' is never read", entity);
4549                 }
4550         }
4551 }
4552
4553 static void check_unused_variables(statement_t *const stmt, void *const env)
4554 {
4555         (void)env;
4556
4557         switch (stmt->kind) {
4558                 case STATEMENT_DECLARATION: {
4559                         declaration_statement_t const *const decls = &stmt->declaration;
4560                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4561                         return;
4562                 }
4563
4564                 case STATEMENT_FOR:
4565                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4566                         return;
4567
4568                 default:
4569                         return;
4570         }
4571 }
4572
4573 /**
4574  * Check declarations of current_function for unused entities.
4575  */
4576 static void check_declarations(void)
4577 {
4578         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4579                 const scope_t *scope = &current_function->parameters;
4580                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4581         }
4582         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4583                 walk_statements(current_function->body, check_unused_variables, NULL);
4584         }
4585 }
4586
4587 static int determine_truth(expression_t const* const cond)
4588 {
4589         return
4590                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4591                 fold_constant_to_bool(cond)                         ? 1 :
4592                 -1;
4593 }
4594
4595 static void check_reachable(statement_t *);
4596 static bool reaches_end;
4597
4598 static bool expression_returns(expression_t const *const expr)
4599 {
4600         switch (expr->kind) {
4601                 case EXPR_CALL: {
4602                         expression_t const *const func = expr->call.function;
4603                         type_t       const *const type = skip_typeref(func->base.type);
4604                         if (type->kind == TYPE_POINTER) {
4605                                 type_t const *const points_to
4606                                         = skip_typeref(type->pointer.points_to);
4607                                 if (points_to->kind == TYPE_FUNCTION
4608                                     && points_to->function.modifiers & DM_NORETURN)
4609                                         return false;
4610                         }
4611
4612                         if (!expression_returns(func))
4613                                 return false;
4614
4615                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4616                                 if (!expression_returns(arg->expression))
4617                                         return false;
4618                         }
4619
4620                         return true;
4621                 }
4622
4623                 case EXPR_REFERENCE:
4624                 case EXPR_ENUM_CONSTANT:
4625                 case EXPR_LITERAL_CASES:
4626                 case EXPR_LITERAL_CHARACTER:
4627                 case EXPR_STRING_LITERAL:
4628                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4629                 case EXPR_LABEL_ADDRESS:
4630                 case EXPR_CLASSIFY_TYPE:
4631                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4632                 case EXPR_ALIGNOF:
4633                 case EXPR_FUNCNAME:
4634                 case EXPR_BUILTIN_CONSTANT_P:
4635                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4636                 case EXPR_OFFSETOF:
4637                 case EXPR_ERROR:
4638                         return true;
4639
4640                 case EXPR_STATEMENT: {
4641                         bool old_reaches_end = reaches_end;
4642                         reaches_end = false;
4643                         check_reachable(expr->statement.statement);
4644                         bool returns = reaches_end;
4645                         reaches_end = old_reaches_end;
4646                         return returns;
4647                 }
4648
4649                 case EXPR_CONDITIONAL:
4650                         // TODO handle constant expression
4651
4652                         if (!expression_returns(expr->conditional.condition))
4653                                 return false;
4654
4655                         if (expr->conditional.true_expression != NULL
4656                                         && expression_returns(expr->conditional.true_expression))
4657                                 return true;
4658
4659                         return expression_returns(expr->conditional.false_expression);
4660
4661                 case EXPR_SELECT:
4662                         return expression_returns(expr->select.compound);
4663
4664                 case EXPR_ARRAY_ACCESS:
4665                         return
4666                                 expression_returns(expr->array_access.array_ref) &&
4667                                 expression_returns(expr->array_access.index);
4668
4669                 case EXPR_VA_START:
4670                         return expression_returns(expr->va_starte.ap);
4671
4672                 case EXPR_VA_ARG:
4673                         return expression_returns(expr->va_arge.ap);
4674
4675                 case EXPR_VA_COPY:
4676                         return expression_returns(expr->va_copye.src);
4677
4678                 case EXPR_UNARY_CASES_MANDATORY:
4679                         return expression_returns(expr->unary.value);
4680
4681                 case EXPR_UNARY_THROW:
4682                         return false;
4683
4684                 case EXPR_BINARY_CASES:
4685                         // TODO handle constant lhs of && and ||
4686                         return
4687                                 expression_returns(expr->binary.left) &&
4688                                 expression_returns(expr->binary.right);
4689         }
4690
4691         panic("unhandled expression");
4692 }
4693
4694 static bool initializer_returns(initializer_t const *const init)
4695 {
4696         switch (init->kind) {
4697                 case INITIALIZER_VALUE:
4698                         return expression_returns(init->value.value);
4699
4700                 case INITIALIZER_LIST: {
4701                         initializer_t * const*       i       = init->list.initializers;
4702                         initializer_t * const* const end     = i + init->list.len;
4703                         bool                         returns = true;
4704                         for (; i != end; ++i) {
4705                                 if (!initializer_returns(*i))
4706                                         returns = false;
4707                         }
4708                         return returns;
4709                 }
4710
4711                 case INITIALIZER_STRING:
4712                 case INITIALIZER_DESIGNATOR: // designators have no payload
4713                         return true;
4714         }
4715         panic("unhandled initializer");
4716 }
4717
4718 static bool noreturn_candidate;
4719
4720 static void check_reachable(statement_t *const stmt)
4721 {
4722         if (stmt->base.reachable)
4723                 return;
4724         if (stmt->kind != STATEMENT_DO_WHILE)
4725                 stmt->base.reachable = true;
4726
4727         statement_t *last = stmt;
4728         statement_t *next;
4729         switch (stmt->kind) {
4730                 case STATEMENT_ERROR:
4731                 case STATEMENT_EMPTY:
4732                 case STATEMENT_ASM:
4733                         next = stmt->base.next;
4734                         break;
4735
4736                 case STATEMENT_DECLARATION: {
4737                         declaration_statement_t const *const decl = &stmt->declaration;
4738                         entity_t                const *      ent  = decl->declarations_begin;
4739                         entity_t                const *const last_decl = decl->declarations_end;
4740                         if (ent != NULL) {
4741                                 for (;; ent = ent->base.next) {
4742                                         if (ent->kind                 == ENTITY_VARIABLE &&
4743                                             ent->variable.initializer != NULL            &&
4744                                             !initializer_returns(ent->variable.initializer)) {
4745                                                 return;
4746                                         }
4747                                         if (ent == last_decl)
4748                                                 break;
4749                                 }
4750                         }
4751                         next = stmt->base.next;
4752                         break;
4753                 }
4754
4755                 case STATEMENT_COMPOUND:
4756                         next = stmt->compound.statements;
4757                         if (next == NULL)
4758                                 next = stmt->base.next;
4759                         break;
4760
4761                 case STATEMENT_RETURN: {
4762                         expression_t const *const val = stmt->returns.value;
4763                         if (val == NULL || expression_returns(val))
4764                                 noreturn_candidate = false;
4765                         return;
4766                 }
4767
4768                 case STATEMENT_IF: {
4769                         if_statement_t const *const ifs  = &stmt->ifs;
4770                         expression_t   const *const cond = ifs->condition;
4771
4772                         if (!expression_returns(cond))
4773                                 return;
4774
4775                         int const val = determine_truth(cond);
4776
4777                         if (val >= 0)
4778                                 check_reachable(ifs->true_statement);
4779
4780                         if (val > 0)
4781                                 return;
4782
4783                         if (ifs->false_statement != NULL) {
4784                                 check_reachable(ifs->false_statement);
4785                                 return;
4786                         }
4787
4788                         next = stmt->base.next;
4789                         break;
4790                 }
4791
4792                 case STATEMENT_SWITCH: {
4793                         switch_statement_t const *const switchs = &stmt->switchs;
4794                         expression_t       const *const expr    = switchs->expression;
4795
4796                         if (!expression_returns(expr))
4797                                 return;
4798
4799                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4800                                 ir_tarval              *const val      = fold_constant_to_tarval(expr);
4801                                 case_label_statement_t *      defaults = NULL;
4802                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4803                                         if (i->expression == NULL) {
4804                                                 defaults = i;
4805                                                 continue;
4806                                         }
4807
4808                                         if (i->first_case == val || i->last_case == val ||
4809                                                 ((tarval_cmp(i->first_case, val) & ir_relation_less_equal)
4810                                             && (tarval_cmp(val, i->last_case) & ir_relation_less_equal))) {
4811                                                 check_reachable((statement_t*)i);
4812                                                 return;
4813                                         }
4814                                 }
4815
4816                                 if (defaults != NULL) {
4817                                         check_reachable((statement_t*)defaults);
4818                                         return;
4819                                 }
4820                         } else {
4821                                 bool has_default = false;
4822                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4823                                         if (i->expression == NULL)
4824                                                 has_default = true;
4825
4826                                         check_reachable((statement_t*)i);
4827                                 }
4828
4829                                 if (has_default)
4830                                         return;
4831                         }
4832
4833                         next = stmt->base.next;
4834                         break;
4835                 }
4836
4837                 case STATEMENT_EXPRESSION: {
4838                         /* Check for noreturn function call */
4839                         expression_t const *const expr = stmt->expression.expression;
4840                         if (!expression_returns(expr))
4841                                 return;
4842
4843                         next = stmt->base.next;
4844                         break;
4845                 }
4846
4847                 case STATEMENT_CONTINUE:
4848                         for (statement_t *parent = stmt;;) {
4849                                 parent = parent->base.parent;
4850                                 if (parent == NULL) /* continue not within loop */
4851                                         return;
4852
4853                                 next = parent;
4854                                 switch (parent->kind) {
4855                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4856                                         case STATEMENT_FOR:      goto continue_for;
4857
4858                                         default: break;
4859                                 }
4860                         }
4861
4862                 case STATEMENT_BREAK:
4863                         for (statement_t *parent = stmt;;) {
4864                                 parent = parent->base.parent;
4865                                 if (parent == NULL) /* break not within loop/switch */
4866                                         return;
4867
4868                                 switch (parent->kind) {
4869                                         case STATEMENT_SWITCH:
4870                                         case STATEMENT_DO_WHILE:
4871                                         case STATEMENT_FOR:
4872                                                 last = parent;
4873                                                 next = parent->base.next;
4874                                                 goto found_break_parent;
4875
4876                                         default: break;
4877                                 }
4878                         }
4879 found_break_parent:
4880                         break;
4881
4882                 case STATEMENT_COMPUTED_GOTO: {
4883                         if (!expression_returns(stmt->computed_goto.expression))
4884                                 return;
4885
4886                         statement_t *parent = stmt->base.parent;
4887                         if (parent == NULL) /* top level goto */
4888                                 return;
4889                         next = parent;
4890                         break;
4891                 }
4892
4893                 case STATEMENT_GOTO:
4894                         next = stmt->gotos.label->statement;
4895                         if (next == NULL) /* missing label */
4896                                 return;
4897                         break;
4898
4899                 case STATEMENT_LABEL:
4900                         next = stmt->label.statement;
4901                         break;
4902
4903                 case STATEMENT_CASE_LABEL:
4904                         next = stmt->case_label.statement;
4905                         break;
4906
4907                 case STATEMENT_DO_WHILE:
4908                         next = stmt->do_while.body;
4909                         break;
4910
4911                 case STATEMENT_FOR: {
4912                         for_statement_t *const fors = &stmt->fors;
4913
4914                         if (fors->condition_reachable)
4915                                 return;
4916                         fors->condition_reachable = true;
4917
4918                         expression_t const *const cond = fors->condition;
4919
4920                         int val;
4921                         if (cond == NULL) {
4922                                 val = 1;
4923                         } else if (expression_returns(cond)) {
4924                                 val = determine_truth(cond);
4925                         } else {
4926                                 return;
4927                         }
4928
4929                         if (val >= 0)
4930                                 check_reachable(fors->body);
4931
4932                         if (val > 0)
4933                                 return;
4934
4935                         next = stmt->base.next;
4936                         break;
4937                 }
4938
4939                 case STATEMENT_MS_TRY: {
4940                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4941                         check_reachable(ms_try->try_statement);
4942                         next = ms_try->final_statement;
4943                         break;
4944                 }
4945
4946                 case STATEMENT_LEAVE: {
4947                         statement_t *parent = stmt;
4948                         for (;;) {
4949                                 parent = parent->base.parent;
4950                                 if (parent == NULL) /* __leave not within __try */
4951                                         return;
4952
4953                                 if (parent->kind == STATEMENT_MS_TRY) {
4954                                         last = parent;
4955                                         next = parent->ms_try.final_statement;
4956                                         break;
4957                                 }
4958                         }
4959                         break;
4960                 }
4961
4962                 default:
4963                         panic("invalid statement kind");
4964         }
4965
4966         while (next == NULL) {
4967                 next = last->base.parent;
4968                 if (next == NULL) {
4969                         noreturn_candidate = false;
4970
4971                         type_t *const type = skip_typeref(current_function->base.type);
4972                         assert(is_type_function(type));
4973                         type_t *const ret  = skip_typeref(type->function.return_type);
4974                         if (!is_type_void(ret) &&
4975                             is_type_valid(ret) &&
4976                             !is_main(current_entity)) {
4977                                 position_t const *const pos = &stmt->base.pos;
4978                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4979                         }
4980                         return;
4981                 }
4982
4983                 switch (next->kind) {
4984                         case STATEMENT_ERROR:
4985                         case STATEMENT_EMPTY:
4986                         case STATEMENT_DECLARATION:
4987                         case STATEMENT_EXPRESSION:
4988                         case STATEMENT_ASM:
4989                         case STATEMENT_RETURN:
4990                         case STATEMENT_CONTINUE:
4991                         case STATEMENT_BREAK:
4992                         case STATEMENT_COMPUTED_GOTO:
4993                         case STATEMENT_GOTO:
4994                         case STATEMENT_LEAVE:
4995                                 panic("invalid control flow in function");
4996
4997                         case STATEMENT_COMPOUND:
4998                                 if (next->compound.stmt_expr) {
4999                                         reaches_end = true;
5000                                         return;
5001                                 }
5002                                 /* FALLTHROUGH */
5003                         case STATEMENT_IF:
5004                         case STATEMENT_SWITCH:
5005                         case STATEMENT_LABEL:
5006                         case STATEMENT_CASE_LABEL:
5007                                 last = next;
5008                                 next = next->base.next;
5009                                 break;
5010
5011                         case STATEMENT_DO_WHILE: {
5012 continue_do_while:
5013                                 if (next->base.reachable)
5014                                         return;
5015                                 next->base.reachable = true;
5016
5017                                 do_while_statement_t const *const dw   = &next->do_while;
5018                                 expression_t         const *const cond = dw->condition;
5019
5020                                 if (!expression_returns(cond))
5021                                         return;
5022
5023                                 int const val = determine_truth(cond);
5024
5025                                 if (val >= 0)
5026                                         check_reachable(dw->body);
5027
5028                                 if (val > 0)
5029                                         return;
5030
5031                                 last = next;
5032                                 next = next->base.next;
5033                                 break;
5034                         }
5035
5036                         case STATEMENT_FOR: {
5037 continue_for:;
5038                                 for_statement_t *const fors = &next->fors;
5039
5040                                 fors->step_reachable = true;
5041
5042                                 if (fors->condition_reachable)
5043                                         return;
5044                                 fors->condition_reachable = true;
5045
5046                                 expression_t const *const cond = fors->condition;
5047
5048                                 int val;
5049                                 if (cond == NULL) {
5050                                         val = 1;
5051                                 } else if (expression_returns(cond)) {
5052                                         val = determine_truth(cond);
5053                                 } else {
5054                                         return;
5055                                 }
5056
5057                                 if (val >= 0)
5058                                         check_reachable(fors->body);
5059
5060                                 if (val > 0)
5061                                         return;
5062
5063                                 last = next;
5064                                 next = next->base.next;
5065                                 break;
5066                         }
5067
5068                         case STATEMENT_MS_TRY:
5069                                 last = next;
5070                                 next = next->ms_try.final_statement;
5071                                 break;
5072                 }
5073         }
5074
5075         check_reachable(next);
5076 }
5077
5078 static void check_unreachable(statement_t* const stmt, void *const env)
5079 {
5080         (void)env;
5081
5082         switch (stmt->kind) {
5083                 case STATEMENT_DO_WHILE:
5084                         if (!stmt->base.reachable) {
5085                                 expression_t const *const cond = stmt->do_while.condition;
5086                                 if (determine_truth(cond) >= 0) {
5087                                         position_t const *const pos = &cond->base.pos;
5088                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5089                                 }
5090                         }
5091                         return;
5092
5093                 case STATEMENT_FOR: {
5094                         for_statement_t const* const fors = &stmt->fors;
5095
5096                         // if init and step are unreachable, cond is unreachable, too
5097                         if (!stmt->base.reachable && !fors->step_reachable) {
5098                                 goto warn_unreachable;
5099                         } else {
5100                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5101                                         position_t const *const pos = &fors->initialisation->base.pos;
5102                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5103                                 }
5104
5105                                 if (!fors->condition_reachable && fors->condition != NULL) {
5106                                         position_t const *const pos = &fors->condition->base.pos;
5107                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5108                                 }
5109
5110                                 if (!fors->step_reachable && fors->step != NULL) {
5111                                         position_t const *const pos = &fors->step->base.pos;
5112                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5113                                 }
5114                         }
5115                         return;
5116                 }
5117
5118                 case STATEMENT_COMPOUND:
5119                         if (stmt->compound.statements != NULL)
5120                                 return;
5121                         goto warn_unreachable;
5122
5123                 case STATEMENT_DECLARATION: {
5124                         /* Only warn if there is at least one declarator with an initializer.
5125                          * This typically occurs in switch statements. */
5126                         declaration_statement_t const *const decl = &stmt->declaration;
5127                         entity_t                const *      ent  = decl->declarations_begin;
5128                         entity_t                const *const last = decl->declarations_end;
5129                         if (ent != NULL) {
5130                                 for (;; ent = ent->base.next) {
5131                                         if (ent->kind                 == ENTITY_VARIABLE &&
5132                                                         ent->variable.initializer != NULL) {
5133                                                 goto warn_unreachable;
5134                                         }
5135                                         if (ent == last)
5136                                                 return;
5137                                 }
5138                         }
5139                 }
5140
5141                 default:
5142 warn_unreachable:
5143                         if (!stmt->base.reachable) {
5144                                 position_t const *const pos = &stmt->base.pos;
5145                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5146                         }
5147                         return;
5148         }
5149 }
5150
5151 static bool is_main(entity_t *entity)
5152 {
5153         static symbol_t *sym_main = NULL;
5154         if (sym_main == NULL) {
5155                 sym_main = symbol_table_insert("main");
5156         }
5157
5158         if (entity->base.symbol != sym_main)
5159                 return false;
5160         /* must be in outermost scope */
5161         if (entity->base.parent_scope != file_scope)
5162                 return false;
5163
5164         return true;
5165 }
5166
5167 static void prepare_main_collect2(entity_t*);
5168
5169 static void parse_external_declaration(void)
5170 {
5171         /* function-definitions and declarations both start with declaration
5172          * specifiers */
5173         add_anchor_token(';');
5174         declaration_specifiers_t specifiers;
5175         parse_declaration_specifiers(&specifiers);
5176         rem_anchor_token(';');
5177
5178         /* must be a declaration */
5179         if (token.kind == ';') {
5180                 parse_anonymous_declaration_rest(&specifiers);
5181                 return;
5182         }
5183
5184         add_anchor_token(',');
5185         add_anchor_token('=');
5186         add_anchor_token(';');
5187         add_anchor_token('{');
5188
5189         /* declarator is common to both function-definitions and declarations */
5190         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5191
5192         rem_anchor_token('{');
5193         rem_anchor_token(';');
5194         rem_anchor_token('=');
5195         rem_anchor_token(',');
5196
5197         /* must be a declaration */
5198         switch (token.kind) {
5199                 case ',':
5200                 case ';':
5201                 case '=':
5202                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5203                                         DECL_FLAGS_NONE);
5204                         return;
5205         }
5206
5207         /* must be a function definition */
5208         parse_kr_declaration_list(ndeclaration);
5209
5210         if (token.kind != '{') {
5211                 parse_error_expected("while parsing function definition", '{', NULL);
5212                 eat_until_matching_token(';');
5213                 return;
5214         }
5215
5216         {
5217                 assert(is_declaration(ndeclaration));
5218                 type_t *const orig_type = ndeclaration->declaration.type;
5219                 type_t *const type      = skip_typeref(orig_type);
5220
5221                 if (!is_type_function(type)) {
5222                         if (is_type_valid(type)) {
5223                                 errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5224                         }
5225                         eat_block();
5226                         return;
5227                 }
5228
5229                 position_t const *const pos = &ndeclaration->base.pos;
5230                 if (is_typeref(orig_type)) {
5231                         /* §6.9.1:2 */
5232                         errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5233                 }
5234
5235                 if (is_type_compound(skip_typeref(type->function.return_type))) {
5236                         warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5237                 }
5238                 if (type->function.unspecified_parameters) {
5239                         warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5240                 } else {
5241                         warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5242                 }
5243
5244                 /* §6.7.5.3:14 a function definition with () means no
5245                  * parameters (and not unspecified parameters) */
5246                 if (type->function.unspecified_parameters &&
5247                                 type->function.parameters == NULL) {
5248                         type_t *copy                          = duplicate_type(type);
5249                         copy->function.unspecified_parameters = false;
5250                         ndeclaration->declaration.type = identify_new_type(copy);
5251                 }
5252         }
5253
5254         entity_t *const entity = record_entity(ndeclaration, true);
5255         assert(entity->kind == ENTITY_FUNCTION);
5256         assert(ndeclaration->kind == ENTITY_FUNCTION);
5257
5258         function_t *const function = &entity->function;
5259         if (ndeclaration != entity) {
5260                 function->parameters = ndeclaration->function.parameters;
5261         }
5262
5263         PUSH_SCOPE(&function->parameters);
5264
5265         entity_t *parameter = function->parameters.entities;
5266         for (; parameter != NULL; parameter = parameter->base.next) {
5267                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5268                         parameter->base.parent_scope = current_scope;
5269                 }
5270                 assert(parameter->base.parent_scope == NULL
5271                                 || parameter->base.parent_scope == current_scope);
5272                 parameter->base.parent_scope = current_scope;
5273                 if (parameter->base.symbol == NULL) {
5274                         errorf(&parameter->base.pos, "parameter name omitted");
5275                         continue;
5276                 }
5277                 environment_push(parameter);
5278         }
5279
5280         if (function->body != NULL) {
5281                 parser_error_multiple_definition(entity, HERE);
5282                 eat_block();
5283         } else {
5284                 /* parse function body */
5285                 int         label_stack_top      = label_top();
5286                 function_t *old_current_function = current_function;
5287                 current_function                 = function;
5288                 PUSH_CURRENT_ENTITY(entity);
5289                 PUSH_PARENT(NULL);
5290
5291                 goto_first   = NULL;
5292                 goto_anchor  = &goto_first;
5293                 label_first  = NULL;
5294                 label_anchor = &label_first;
5295
5296                 statement_t *const body = parse_compound_statement(false);
5297                 function->body = body;
5298                 first_err = true;
5299                 check_labels();
5300                 check_declarations();
5301                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5302                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5303                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5304                         noreturn_candidate = true;
5305                         check_reachable(body);
5306                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5307                                 walk_statements(body, check_unreachable, NULL);
5308                         if (noreturn_candidate &&
5309                             !(function->base.modifiers & DM_NORETURN)) {
5310                                 warningf(WARN_MISSING_NORETURN, &body->base.pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5311                         }
5312                 }
5313
5314                 if (is_main(entity)) {
5315                         /* Force main to C linkage. */
5316                         type_t *const type = entity->declaration.type;
5317                         assert(is_type_function(type));
5318                         if (type->function.linkage != LINKAGE_C) {
5319                                 type_t *new_type           = duplicate_type(type);
5320                                 new_type->function.linkage = LINKAGE_C;
5321                                 entity->declaration.type   = identify_new_type(new_type);
5322                         }
5323
5324                         if (enable_main_collect2_hack)
5325                                 prepare_main_collect2(entity);
5326                 }
5327
5328                 POP_CURRENT_ENTITY();
5329                 POP_PARENT();
5330                 assert(current_function == function);
5331                 current_function = old_current_function;
5332                 label_pop_to(label_stack_top);
5333         }
5334
5335         POP_SCOPE();
5336 }
5337
5338 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5339 {
5340         entity_t *iter = compound->members.entities;
5341         for (; iter != NULL; iter = iter->base.next) {
5342                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5343                         continue;
5344
5345                 if (iter->base.symbol == symbol) {
5346                         return iter;
5347                 } else if (iter->base.symbol == NULL) {
5348                         /* search in anonymous structs and unions */
5349                         type_t *type = skip_typeref(iter->declaration.type);
5350                         if (is_type_compound(type)) {
5351                                 if (find_compound_entry(type->compound.compound, symbol)
5352                                                 != NULL)
5353                                         return iter;
5354                         }
5355                         continue;
5356                 }
5357         }
5358
5359         return NULL;
5360 }
5361
5362 static void check_deprecated(const position_t *pos, const entity_t *entity)
5363 {
5364         if (!is_declaration(entity))
5365                 return;
5366         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5367                 return;
5368
5369         position_t const *const epos = &entity->base.pos;
5370         char       const *const msg  = get_deprecated_string(entity->declaration.attributes);
5371         if (msg != NULL) {
5372                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5373         } else {
5374                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P)", entity, epos);
5375         }
5376 }
5377
5378
5379 static expression_t *create_select(const position_t *pos, expression_t *addr,
5380                                    type_qualifiers_t qualifiers,
5381                                                                    entity_t *entry)
5382 {
5383         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5384
5385         check_deprecated(pos, entry);
5386
5387         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5388         select->base.pos              = *pos;
5389         select->select.compound       = addr;
5390         select->select.compound_entry = entry;
5391
5392         type_t *entry_type = entry->declaration.type;
5393         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5394
5395         /* bitfields need special treatment */
5396         if (entry->compound_member.bitfield) {
5397                 unsigned bit_size = entry->compound_member.bit_size;
5398                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5399                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5400                         res_type = type_int;
5401                 }
5402         }
5403
5404         /* we always do the auto-type conversions; the & and sizeof parser contains
5405          * code to revert this! */
5406         select->base.type = automatic_type_conversion(res_type);
5407
5408
5409         return select;
5410 }
5411
5412 /**
5413  * Find entry with symbol in compound. Search anonymous structs and unions and
5414  * creates implicit select expressions for them.
5415  * Returns the adress for the innermost compound.
5416  */
5417 static expression_t *find_create_select(const position_t *pos,
5418                                         expression_t *addr,
5419                                         type_qualifiers_t qualifiers,
5420                                         compound_t *compound, symbol_t *symbol)
5421 {
5422         entity_t *iter = compound->members.entities;
5423         for (; iter != NULL; iter = iter->base.next) {
5424                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5425                         continue;
5426
5427                 symbol_t *iter_symbol = iter->base.symbol;
5428                 if (iter_symbol == NULL) {
5429                         type_t *type = iter->declaration.type;
5430                         if (!is_type_compound(type))
5431                                 continue;
5432
5433                         compound_t *sub_compound = type->compound.compound;
5434
5435                         if (find_compound_entry(sub_compound, symbol) == NULL)
5436                                 continue;
5437
5438                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5439                         sub_addr->base.implicit = true;
5440                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5441                                                   symbol);
5442                 }
5443
5444                 if (iter_symbol == symbol) {
5445                         return create_select(pos, addr, qualifiers, iter);
5446                 }
5447         }
5448
5449         return NULL;
5450 }
5451
5452 static void parse_bitfield_member(entity_t *entity)
5453 {
5454         eat(':');
5455
5456         expression_t *size = parse_constant_expression();
5457         long          size_long;
5458
5459         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5460         type_t *type = entity->declaration.type;
5461         if (!is_type_integer(skip_typeref(type))) {
5462                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5463                            type);
5464         }
5465
5466         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5467                 /* error already reported by parse_constant_expression */
5468                 size_long = get_type_size(type) * 8;
5469         } else {
5470                 size_long = fold_constant_to_int(size);
5471
5472                 const symbol_t *symbol = entity->base.symbol;
5473                 const symbol_t *user_symbol
5474                         = symbol == NULL ? sym_anonymous : symbol;
5475                 unsigned bit_size = get_type_size(type) * 8;
5476                 if (size_long < 0) {
5477                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5478                 } else if (size_long == 0 && symbol != NULL) {
5479                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5480                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5481                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5482                                    user_symbol);
5483                 } else {
5484                         /* hope that people don't invent crazy types with more bits
5485                          * than our struct can hold */
5486                         assert(size_long <
5487                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5488                 }
5489         }
5490
5491         entity->compound_member.bitfield = true;
5492         entity->compound_member.bit_size = (unsigned char)size_long;
5493 }
5494
5495 static void parse_compound_declarators(compound_t *compound,
5496                 const declaration_specifiers_t *specifiers)
5497 {
5498         add_anchor_token(';');
5499         add_anchor_token(',');
5500         do {
5501                 entity_t *entity;
5502                 if (token.kind == ':') {
5503                         /* anonymous bitfield */
5504                         type_t *type = specifiers->type;
5505                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5506                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5507                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5508                         entity->declaration.type                   = type;
5509
5510                         parse_bitfield_member(entity);
5511
5512                         attribute_t  *attributes = parse_attributes(NULL);
5513                         attribute_t **anchor     = &attributes;
5514                         while (*anchor != NULL)
5515                                 anchor = &(*anchor)->next;
5516                         *anchor = specifiers->attributes;
5517                         if (attributes != NULL) {
5518                                 handle_entity_attributes(attributes, entity);
5519                         }
5520                         entity->declaration.attributes = attributes;
5521                 } else {
5522                         entity = parse_declarator(specifiers, DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5523                         position_t const *const pos = &entity->base.pos;
5524                         if (entity->kind == ENTITY_TYPEDEF) {
5525                                 errorf(pos, "typedef not allowed as compound member");
5526                                 continue;
5527                         }
5528
5529                         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5530
5531                         /* make sure we don't define a symbol multiple times */
5532                         symbol_t *symbol = entity->base.symbol;
5533                         if (symbol != NULL) {
5534                                 entity_t *prev = find_compound_entry(compound, symbol);
5535                                 if (prev != NULL) {
5536                                         position_t const *const ppos = &prev->base.pos;
5537                                         errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5538                                 }
5539                         }
5540
5541                         if (token.kind == ':') {
5542                                 parse_bitfield_member(entity);
5543
5544                                 attribute_t *attributes = parse_attributes(NULL);
5545                                 handle_entity_attributes(attributes, entity);
5546                         } else {
5547                                 type_t *orig_type = entity->declaration.type;
5548                                 type_t *type      = skip_typeref(orig_type);
5549                                 if (is_type_function(type)) {
5550                                         errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5551                                 } else if (is_type_incomplete(type)) {
5552                                         /* §6.7.2.1:16 flexible array member */
5553                                         if (!is_type_array(type)       ||
5554                                                         token.kind          != ';' ||
5555                                                         look_ahead(1)->kind != '}') {
5556                                                 errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5557                                         } else if (compound->members.entities == NULL) {
5558                                                 errorf(pos, "flexible array member in otherwise empty struct");
5559                                         }
5560                                 }
5561                         }
5562                 }
5563
5564                 append_entity(&compound->members, entity);
5565         } while (accept(','));
5566         rem_anchor_token(',');
5567         rem_anchor_token(';');
5568         expect(';');
5569
5570         anonymous_entity = NULL;
5571 }
5572
5573 static void parse_compound_type_entries(compound_t *compound)
5574 {
5575         eat('{');
5576         add_anchor_token('}');
5577
5578         for (;;) {
5579                 switch (token.kind) {
5580                         DECLARATION_START
5581                         case T___extension__:
5582                         case T_IDENTIFIER: {
5583                                 PUSH_EXTENSION();
5584                                 declaration_specifiers_t specifiers;
5585                                 parse_declaration_specifiers(&specifiers);
5586                                 parse_compound_declarators(compound, &specifiers);
5587                                 POP_EXTENSION();
5588                                 break;
5589                         }
5590
5591                         default:
5592                                 rem_anchor_token('}');
5593                                 expect('}');
5594                                 /* §6.7.2.1:7 */
5595                                 compound->complete = true;
5596                                 return;
5597                 }
5598         }
5599 }
5600
5601 static type_t *parse_typename(void)
5602 {
5603         declaration_specifiers_t specifiers;
5604         parse_declaration_specifiers(&specifiers);
5605         if (specifiers.storage_class != STORAGE_CLASS_NONE
5606                         || specifiers.thread_local) {
5607                 /* TODO: improve error message, user does probably not know what a
5608                  * storage class is...
5609                  */
5610                 errorf(&specifiers.pos, "typename must not have a storage class");
5611         }
5612
5613         type_t *result = parse_abstract_declarator(specifiers.type);
5614
5615         return result;
5616 }
5617
5618
5619
5620
5621 typedef expression_t* (*parse_expression_function)(void);
5622 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5623
5624 typedef struct expression_parser_function_t expression_parser_function_t;
5625 struct expression_parser_function_t {
5626         parse_expression_function        parser;
5627         precedence_t                     infix_precedence;
5628         parse_expression_infix_function  infix_parser;
5629 };
5630
5631 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5632
5633 static type_t *get_string_type(string_encoding_t const enc)
5634 {
5635         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5636         switch (enc) {
5637         case STRING_ENCODING_CHAR:
5638         case STRING_ENCODING_UTF8:   return warn ? type_const_char_ptr     : type_char_ptr;
5639         case STRING_ENCODING_CHAR16: return warn ? type_char16_t_const_ptr : type_char16_t_ptr;
5640         case STRING_ENCODING_CHAR32: return warn ? type_char32_t_const_ptr : type_char32_t_ptr;
5641         case STRING_ENCODING_WIDE:   return warn ? type_const_wchar_t_ptr  : type_wchar_t_ptr;
5642         }
5643         panic("invalid string encoding");
5644 }
5645
5646 /**
5647  * Parse a string constant.
5648  */
5649 static expression_t *parse_string_literal(void)
5650 {
5651         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5652         expr->string_literal.value = concat_string_literals();
5653         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5654         return expr;
5655 }
5656
5657 /**
5658  * Parse a boolean constant.
5659  */
5660 static expression_t *parse_boolean_literal(bool value)
5661 {
5662         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5663         literal->base.type           = type_bool;
5664         literal->literal.value.begin = value ? "true" : "false";
5665         literal->literal.value.size  = value ? 4 : 5;
5666
5667         eat(value ? T_true : T_false);
5668         return literal;
5669 }
5670
5671 static void check_number_suffix(expression_t *const expr, char const *const suffix, bool const is_float)
5672 {
5673         unsigned spec = SPECIFIER_NONE;
5674         for (char const *c = suffix; *c != '\0'; ++c) {
5675                 specifiers_t add;
5676                 switch (*c) {
5677                 case 'F': case 'f':
5678                         add = SPECIFIER_FLOAT;
5679                         break;
5680
5681                 case 'L': case 'l':
5682                         add = SPECIFIER_LONG;
5683                         if (*c == c[1] && !is_float) {
5684                                 add |= SPECIFIER_LONG_LONG;
5685                                 ++c;
5686                         }
5687                         break;
5688
5689                 case 'U': case 'u':
5690                         add = SPECIFIER_UNSIGNED;
5691                         break;
5692
5693                 case 'I': case 'i':
5694                 case 'J': case 'j':
5695                         add = SPECIFIER_COMPLEX;
5696                         break;
5697
5698                 default:
5699                         goto error;
5700                 }
5701                 if (spec & add)
5702                         goto error;
5703                 spec |= add;
5704         }
5705
5706         if (!(spec & SPECIFIER_FLOAT) && is_float)
5707                 spec |= SPECIFIER_DOUBLE;
5708
5709         if (!(spec & (SPECIFIER_FLOAT | SPECIFIER_DOUBLE)) == is_float)
5710                 goto error;
5711
5712         type_t *type;
5713         switch (spec & ~SPECIFIER_COMPLEX) {
5714         case SPECIFIER_NONE:                                            type = type_int;                break;
5715         case                      SPECIFIER_LONG:                       type = type_long;               break;
5716         case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5717         case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5718         case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5719         case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5720         case SPECIFIER_FLOAT:                                           type = type_float;              break;
5721         case SPECIFIER_DOUBLE:                                          type = type_double;             break;
5722         case SPECIFIER_DOUBLE   | SPECIFIER_LONG:                       type = type_long_double;        break;
5723
5724         default:
5725 error:
5726                 errorf(HERE, "invalid suffix '%s' on %s constant", suffix, is_float ? "floatingpoint" : "integer");
5727                 return;
5728         }
5729
5730         if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG && spec != SPECIFIER_DOUBLE)
5731                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5732
5733         if (spec & SPECIFIER_COMPLEX)
5734                 type = make_complex_type(get_arithmetic_akind(type), TYPE_QUALIFIER_NONE);
5735
5736         expr->base.type = type;
5737         if (!is_float) {
5738                 /* Integer type depends on the size of the number and the size
5739                  * representable by the types. The backend/codegeneration has to
5740                  * determine that. */
5741                 determine_literal_type(&expr->literal);
5742         }
5743 }
5744
5745 static expression_t *parse_number_literal(void)
5746 {
5747         string_t const *const str      = &token.literal.string;
5748         char     const *      i        = str->begin;
5749         unsigned              digits   = 0;
5750         bool                  is_float = false;
5751
5752         /* Parse base prefix. */
5753         unsigned base;
5754         if (*i == '0') {
5755                 switch (*++i) {
5756                 case 'B': case 'b': base =  2; ++i;               break;
5757                 case 'X': case 'x': base = 16; ++i;               break;
5758                 default:            base =  8; digits |= 1U << 0; break;
5759                 }
5760         } else {
5761                 base = 10;
5762         }
5763
5764         /* Parse mantissa. */
5765         for (;; ++i) {
5766                 unsigned digit;
5767                 switch (*i) {
5768                 case '.':
5769                         if (is_float) {
5770                                 errorf(HERE, "multiple decimal points in %K", &token);
5771                                 i = 0;
5772                                 goto done;
5773                         }
5774                         is_float = true;
5775                         if (base == 8)
5776                                 base = 10;
5777                         continue;
5778
5779                 case '0':           digit =  0; break;
5780                 case '1':           digit =  1; break;
5781                 case '2':           digit =  2; break;
5782                 case '3':           digit =  3; break;
5783                 case '4':           digit =  4; break;
5784                 case '5':           digit =  5; break;
5785                 case '6':           digit =  6; break;
5786                 case '7':           digit =  7; break;
5787                 case '8':           digit =  8; break;
5788                 case '9':           digit =  9; break;
5789                 case 'A': case 'a': digit = 10; break;
5790                 case 'B': case 'b': digit = 11; break;
5791                 case 'C': case 'c': digit = 12; break;
5792                 case 'D': case 'd': digit = 13; break;
5793                 case 'E': case 'e': digit = 14; break;
5794                 case 'F': case 'f': digit = 15; break;
5795
5796                 default: goto done_mantissa;
5797                 }
5798
5799                 if (digit >= 10 && base != 16)
5800                         goto done_mantissa;
5801
5802                 digits |= 1U << digit;
5803         }
5804 done_mantissa:
5805
5806         /* Parse exponent. */
5807         switch (base) {
5808         case 2:
5809                 if (is_float)
5810                         errorf(HERE, "binary floating %K not allowed", &token);
5811                 break;
5812
5813         case  8:
5814         case 10:
5815                 if (*i == 'E' || *i == 'e') {
5816                         base = 10;
5817                         goto parse_exponent;
5818                 }
5819                 break;
5820
5821         case 16:
5822                 if (*i == 'P' || *i == 'p') {
5823 parse_exponent:
5824                         ++i;
5825                         is_float = true;
5826
5827                         if (*i == '-' || *i == '+')
5828                                 ++i;
5829
5830                         if (isdigit(*i)) {
5831                                 do {
5832                                         ++i;
5833                                 } while (isdigit(*i));
5834                         } else {
5835                                 errorf(HERE, "exponent of %K has no digits", &token);
5836                         }
5837                 } else if (is_float) {
5838                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5839                         i = 0;
5840                 }
5841                 break;
5842
5843         default:
5844                 panic("invalid base");
5845         }
5846
5847 done:;
5848         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5849         expr->literal.value = *str;
5850
5851         if (i) {
5852                 if (digits == 0) {
5853                         errorf(HERE, "%K has no digits", &token);
5854                 } else if (digits & ~((1U << base) - 1)) {
5855                         errorf(HERE, "invalid digit in %K", &token);
5856                 } else {
5857                         expr->literal.suffix = i;
5858                         check_number_suffix(expr, i, is_float);
5859                 }
5860         }
5861
5862         eat(T_NUMBER);
5863         return expr;
5864 }
5865
5866 /**
5867  * Parse a character constant.
5868  */
5869 static expression_t *parse_character_constant(void)
5870 {
5871         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5872         literal->string_literal.value = token.literal.string;
5873
5874         size_t const size = get_string_len(&token.literal.string);
5875         switch (token.literal.string.encoding) {
5876         case STRING_ENCODING_CHAR:
5877         case STRING_ENCODING_UTF8:
5878                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5879                 if (size > 1) {
5880                         if (!GNU_MODE && !(c_mode & _C99)) {
5881                                 errorf(HERE, "more than 1 character in character constant");
5882                         } else {
5883                                 literal->base.type = type_int;
5884                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5885                         }
5886                 }
5887                 break;
5888
5889         case STRING_ENCODING_CHAR16: literal->base.type = type_char16_t; goto warn_multi;
5890         case STRING_ENCODING_CHAR32: literal->base.type = type_char32_t; goto warn_multi;
5891         case STRING_ENCODING_WIDE:   literal->base.type = type_wchar_t;  goto warn_multi;
5892 warn_multi:
5893                 if (size > 1) {
5894                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5895                 }
5896                 break;
5897         }
5898
5899         eat(T_CHARACTER_CONSTANT);
5900         return literal;
5901 }
5902
5903 static entity_t *create_implicit_function(symbol_t *symbol, position_t const *const pos)
5904 {
5905         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5906         ntype->function.return_type            = type_int;
5907         ntype->function.unspecified_parameters = true;
5908         ntype->function.linkage                = LINKAGE_C;
5909         type_t *type                           = identify_new_type(ntype);
5910
5911         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5912         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5913         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5914         entity->declaration.type                   = type;
5915         entity->declaration.implicit               = true;
5916
5917         if (current_scope != NULL)
5918                 record_entity(entity, false);
5919
5920         return entity;
5921 }
5922
5923 /**
5924  * Performs automatic type cast as described in §6.3.2.1.
5925  *
5926  * @param orig_type  the original type
5927  */
5928 static type_t *automatic_type_conversion(type_t *orig_type)
5929 {
5930         type_t *type = skip_typeref(orig_type);
5931         if (is_type_array(type)) {
5932                 array_type_t *array_type   = &type->array;
5933                 type_t       *element_type = array_type->element_type;
5934                 unsigned      qualifiers   = array_type->base.qualifiers;
5935
5936                 return make_pointer_type(element_type, qualifiers);
5937         }
5938
5939         if (is_type_function(type)) {
5940                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5941         }
5942
5943         return orig_type;
5944 }
5945
5946 /**
5947  * reverts the automatic casts of array to pointer types and function
5948  * to function-pointer types as defined §6.3.2.1
5949  */
5950 type_t *revert_automatic_type_conversion(const expression_t *expression)
5951 {
5952         switch (expression->kind) {
5953         case EXPR_REFERENCE: {
5954                 entity_t *entity = expression->reference.entity;
5955                 if (is_declaration(entity)) {
5956                         return entity->declaration.type;
5957                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5958                         return entity->enum_value.enum_type;
5959                 } else {
5960                         panic("no declaration or enum in reference");
5961                 }
5962         }
5963
5964         case EXPR_SELECT: {
5965                 entity_t *entity = expression->select.compound_entry;
5966                 assert(is_declaration(entity));
5967                 type_t   *type   = entity->declaration.type;
5968                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5969         }
5970
5971         case EXPR_UNARY_DEREFERENCE: {
5972                 const expression_t *const value = expression->unary.value;
5973                 type_t             *const type  = skip_typeref(value->base.type);
5974                 if (!is_type_pointer(type))
5975                         return type_error_type;
5976                 return type->pointer.points_to;
5977         }
5978
5979         case EXPR_ARRAY_ACCESS: {
5980                 const expression_t *array_ref = expression->array_access.array_ref;
5981                 type_t             *type_left = skip_typeref(array_ref->base.type);
5982                 if (!is_type_pointer(type_left))
5983                         return type_error_type;
5984                 return type_left->pointer.points_to;
5985         }
5986
5987         case EXPR_STRING_LITERAL: {
5988                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
5989                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
5990                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
5991         }
5992
5993         case EXPR_COMPOUND_LITERAL:
5994                 return expression->compound_literal.type;
5995
5996         default:
5997                 break;
5998         }
5999         return expression->base.type;
6000 }
6001
6002 /**
6003  * Find an entity matching a symbol in a scope.
6004  * Uses current scope if scope is NULL
6005  */
6006 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6007                                namespace_tag_t namespc)
6008 {
6009         if (scope == NULL) {
6010                 return get_entity(symbol, namespc);
6011         }
6012
6013         /* we should optimize here, if scope grows above a certain size we should
6014            construct a hashmap here... */
6015         entity_t *entity = scope->entities;
6016         for ( ; entity != NULL; entity = entity->base.next) {
6017                 if (entity->base.symbol == symbol
6018                     && (namespace_tag_t)entity->base.namespc == namespc)
6019                         break;
6020         }
6021
6022         return entity;
6023 }
6024
6025 static entity_t *parse_qualified_identifier(void)
6026 {
6027         /* namespace containing the symbol */
6028         symbol_t      *symbol;
6029         position_t     pos;
6030         const scope_t *lookup_scope = NULL;
6031
6032         if (accept(T_COLONCOLON))
6033                 lookup_scope = &unit->scope;
6034
6035         entity_t *entity;
6036         while (true) {
6037                 symbol = expect_identifier("while parsing identifier", &pos);
6038                 if (!symbol)
6039                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6040
6041                 /* lookup entity */
6042                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6043
6044                 if (!accept(T_COLONCOLON))
6045                         break;
6046
6047                 switch (entity->kind) {
6048                 case ENTITY_NAMESPACE:
6049                         lookup_scope = &entity->namespacee.members;
6050                         break;
6051                 case ENTITY_STRUCT:
6052                 case ENTITY_UNION:
6053                 case ENTITY_CLASS:
6054                         lookup_scope = &entity->compound.members;
6055                         break;
6056                 default:
6057                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6058                                symbol, get_entity_kind_name(entity->kind));
6059
6060                         /* skip further qualifications */
6061                         while (accept(T_IDENTIFIER) && accept(T_COLONCOLON)) {}
6062
6063                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6064                 }
6065         }
6066
6067         if (entity == NULL) {
6068                 if (!strict_mode && token.kind == '(') {
6069                         /* an implicitly declared function */
6070                         entity = create_implicit_function(symbol, &pos);
6071                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6072                 } else {
6073                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6074                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6075                 }
6076         }
6077
6078         return entity;
6079 }
6080
6081 static expression_t *parse_reference(void)
6082 {
6083         position_t const pos    = *HERE;
6084         entity_t  *const entity = parse_qualified_identifier();
6085
6086         type_t *orig_type;
6087         if (is_declaration(entity)) {
6088                 orig_type = entity->declaration.type;
6089         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6090                 orig_type = entity->enum_value.enum_type;
6091         } else {
6092                 panic("expected declaration or enum value in reference");
6093         }
6094
6095         /* we always do the auto-type conversions; the & and sizeof parser contains
6096          * code to revert this! */
6097         type_t *type = automatic_type_conversion(orig_type);
6098
6099         expression_kind_t kind = EXPR_REFERENCE;
6100         if (entity->kind == ENTITY_ENUM_VALUE)
6101                 kind = EXPR_ENUM_CONSTANT;
6102
6103         expression_t *expression     = allocate_expression_zero(kind);
6104         expression->base.pos         = pos;
6105         expression->base.type        = type;
6106         expression->reference.entity = entity;
6107
6108         /* this declaration is used */
6109         if (is_declaration(entity)) {
6110                 entity->declaration.used = true;
6111         }
6112
6113         if (entity->base.parent_scope != file_scope
6114                 && (current_function != NULL
6115                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6116                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6117                 /* access of a variable from an outer function */
6118                 entity->variable.address_taken = true;
6119                 current_function->need_closure = true;
6120         }
6121
6122         check_deprecated(&pos, entity);
6123
6124         return expression;
6125 }
6126
6127 static bool semantic_cast(expression_t *cast)
6128 {
6129         expression_t     *expression      = cast->unary.value;
6130         type_t           *orig_dest_type  = cast->base.type;
6131         type_t           *orig_type_right = expression->base.type;
6132         type_t     const *dst_type        = skip_typeref(orig_dest_type);
6133         type_t     const *src_type        = skip_typeref(orig_type_right);
6134         position_t const *pos             = &cast->base.pos;
6135
6136         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation
6137          * than for utility. */
6138         if (is_type_void(dst_type))
6139                 return true;
6140
6141         /* only integer and pointer can be casted to pointer */
6142         if (is_type_pointer(dst_type)  &&
6143             !is_type_pointer(src_type) &&
6144             !is_type_integer(src_type) &&
6145             is_type_valid(src_type)) {
6146                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6147                 return false;
6148         }
6149
6150         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6151                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6152                 return false;
6153         }
6154
6155         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6156                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6157                 return false;
6158         }
6159
6160         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6161                 type_t *src = skip_typeref(src_type->pointer.points_to);
6162                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6163                 unsigned missing_qualifiers =
6164                         src->base.qualifiers & ~dst->base.qualifiers;
6165                 if (missing_qualifiers != 0) {
6166                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6167                 }
6168         }
6169         return true;
6170 }
6171
6172 static void semantic_complex_extract(unary_expression_t *extract)
6173 {
6174         type_t *orig_value_type = extract->value->base.type;
6175         type_t *value_type      = skip_typeref(orig_value_type);
6176         if (!is_type_valid(value_type)) {
6177                 extract->base.type = type_error_type;
6178                 return;
6179         }
6180
6181         type_t *type = value_type;
6182         if (!is_type_complex(type)) {
6183                 if (!is_type_arithmetic(type)) {
6184                         errorf(&extract->base.pos,
6185                                    "%s requires an argument with complex or arithmetic type, got '%T'",
6186                                    extract->base.kind == EXPR_UNARY_IMAG ? "__imag__" : "__real__",
6187                                    orig_value_type);
6188                         extract->base.type = type_error_type;
6189                         return;
6190                 }
6191                 atomic_type_kind_t const akind = get_arithmetic_akind(type);
6192                 type = make_complex_type(akind, TYPE_QUALIFIER_NONE);
6193                 extract->value = create_implicit_cast(extract->value, type);
6194         }
6195         assert(type->kind == TYPE_COMPLEX);
6196         type = make_atomic_type(type->atomic.akind, TYPE_QUALIFIER_NONE);
6197         extract->base.type = type;
6198 }
6199
6200 static expression_t *parse_compound_literal(position_t const *const pos,
6201                                             type_t *type)
6202 {
6203         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6204         expression->base.pos = *pos;
6205         bool global_scope = current_scope == file_scope;
6206
6207         parse_initializer_env_t env;
6208         env.type             = type;
6209         env.entity           = NULL;
6210         env.must_be_constant = global_scope;
6211         initializer_t *initializer = parse_initializer(&env);
6212         type = env.type;
6213
6214         expression->base.type                     = automatic_type_conversion(type);
6215         expression->compound_literal.initializer  = initializer;
6216         expression->compound_literal.type         = type;
6217         expression->compound_literal.global_scope = global_scope;
6218
6219         return expression;
6220 }
6221
6222 /**
6223  * Parse a cast expression.
6224  */
6225 static expression_t *parse_cast(void)
6226 {
6227         position_t const pos = *HERE;
6228
6229         eat('(');
6230         add_anchor_token(')');
6231
6232         type_t *type = parse_typename();
6233
6234         rem_anchor_token(')');
6235         expect(')');
6236
6237         if (token.kind == '{') {
6238                 return parse_compound_literal(&pos, type);
6239         }
6240
6241         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6242         cast->base.pos     = pos;
6243
6244         expression_t *value = parse_subexpression(PREC_CAST);
6245         cast->base.type   = type;
6246         cast->unary.value = value;
6247
6248         if (!semantic_cast(cast)) {
6249                 cast->base.type = type_error_type;
6250         }
6251
6252         return cast;
6253 }
6254
6255 static expression_t *parse_complex_extract_expression(expression_kind_t const kind)
6256 {
6257         expression_t *extract = allocate_expression_zero(kind);
6258         next_token();
6259
6260         extract->unary.value = parse_subexpression(PREC_CAST);
6261         semantic_complex_extract(&extract->unary);
6262         return extract;
6263 }
6264
6265 /**
6266  * Parse a statement expression.
6267  */
6268 static expression_t *parse_statement_expression(void)
6269 {
6270         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6271
6272         eat('(');
6273         add_anchor_token(')');
6274
6275         statement_t *statement          = parse_compound_statement(true);
6276         statement->compound.stmt_expr   = true;
6277         expression->statement.statement = statement;
6278
6279         /* find last statement and use its type */
6280         type_t *type = type_void;
6281         const statement_t *stmt = statement->compound.statements;
6282         if (stmt != NULL) {
6283                 while (stmt->base.next != NULL)
6284                         stmt = stmt->base.next;
6285
6286                 if (stmt->kind == STATEMENT_EXPRESSION) {
6287                         type = stmt->expression.expression->base.type;
6288                 }
6289         } else {
6290                 position_t const *const pos = &expression->base.pos;
6291                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6292         }
6293         expression->base.type = type;
6294
6295         rem_anchor_token(')');
6296         expect(')');
6297         return expression;
6298 }
6299
6300 /**
6301  * Parse a parenthesized expression.
6302  */
6303 static expression_t *parse_parenthesized_expression(void)
6304 {
6305         token_t const* const la1 = look_ahead(1);
6306         switch (la1->kind) {
6307         case '{':
6308                 /* gcc extension: a statement expression */
6309                 return parse_statement_expression();
6310
6311         case T_IDENTIFIER:
6312                 if (is_typedef_symbol(la1->base.symbol)) {
6313         DECLARATION_START
6314                         return parse_cast();
6315                 }
6316         }
6317
6318         eat('(');
6319         add_anchor_token(')');
6320         expression_t *result = parse_expression();
6321         result->base.parenthesized = true;
6322         rem_anchor_token(')');
6323         expect(')');
6324
6325         return result;
6326 }
6327
6328 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6329 {
6330         if (current_function == NULL) {
6331                 errorf(HERE, "%K used outside of a function", &token);
6332         }
6333
6334         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6335         expression->base.type     = type_char_ptr;
6336         expression->funcname.kind = kind;
6337
6338         next_token();
6339
6340         return expression;
6341 }
6342
6343 static designator_t *parse_designator(void)
6344 {
6345         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6346         result->symbol = expect_identifier("while parsing member designator", &result->pos);
6347         if (!result->symbol)
6348                 return NULL;
6349
6350         designator_t *last_designator = result;
6351         while (true) {
6352                 if (accept('.')) {
6353                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6354                         designator->symbol = expect_identifier("while parsing member designator", &designator->pos);
6355                         if (!designator->symbol)
6356                                 return NULL;
6357
6358                         last_designator->next = designator;
6359                         last_designator       = designator;
6360                         continue;
6361                 }
6362                 if (accept('[')) {
6363                         add_anchor_token(']');
6364                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
6365                         designator->pos          = *HERE;
6366                         designator->array_index  = parse_expression();
6367                         rem_anchor_token(']');
6368                         expect(']');
6369
6370                         last_designator->next = designator;
6371                         last_designator       = designator;
6372                         continue;
6373                 }
6374                 break;
6375         }
6376
6377         return result;
6378 }
6379
6380 /**
6381  * Parse the __builtin_offsetof() expression.
6382  */
6383 static expression_t *parse_offsetof(void)
6384 {
6385         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6386         expression->base.type    = type_size_t;
6387
6388         eat(T___builtin_offsetof);
6389
6390         add_anchor_token(')');
6391         add_anchor_token(',');
6392         expect('(');
6393         type_t *type = parse_typename();
6394         rem_anchor_token(',');
6395         expect(',');
6396         designator_t *designator = parse_designator();
6397         rem_anchor_token(')');
6398         expect(')');
6399
6400         expression->offsetofe.type       = type;
6401         expression->offsetofe.designator = designator;
6402
6403         type_path_t path;
6404         memset(&path, 0, sizeof(path));
6405         path.top_type = type;
6406         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6407
6408         descend_into_subtype(&path);
6409
6410         if (!walk_designator(&path, designator, true)) {
6411                 return create_error_expression();
6412         }
6413
6414         DEL_ARR_F(path.path);
6415
6416         return expression;
6417 }
6418
6419 static bool is_last_parameter(expression_t *const param)
6420 {
6421         if (param->kind == EXPR_REFERENCE) {
6422                 entity_t *const entity = param->reference.entity;
6423                 if (entity->kind == ENTITY_PARAMETER &&
6424                     !entity->base.next               &&
6425                     entity->base.parent_scope == &current_function->parameters) {
6426                         return true;
6427                 }
6428         }
6429
6430         if (!is_type_valid(skip_typeref(param->base.type)))
6431                 return true;
6432
6433         return false;
6434 }
6435
6436 /**
6437  * Parses a __builtin_va_start() expression.
6438  */
6439 static expression_t *parse_va_start(void)
6440 {
6441         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6442
6443         eat(T___builtin_va_start);
6444
6445         add_anchor_token(')');
6446         add_anchor_token(',');
6447         expect('(');
6448         expression->va_starte.ap = parse_assignment_expression();
6449         rem_anchor_token(',');
6450         expect(',');
6451         expression_t *const param = parse_assignment_expression();
6452         expression->va_starte.parameter = param;
6453         rem_anchor_token(')');
6454         expect(')');
6455
6456         if (!current_function) {
6457                 errorf(&expression->base.pos, "'va_start' used outside of function");
6458         } else if (!current_function->base.type->function.variadic) {
6459                 errorf(&expression->base.pos, "'va_start' used in non-variadic function");
6460         } else if (!is_last_parameter(param)) {
6461                 errorf(&param->base.pos, "second argument of 'va_start' must be last parameter of the current function");
6462         }
6463
6464         return expression;
6465 }
6466
6467 /**
6468  * Parses a __builtin_va_arg() expression.
6469  */
6470 static expression_t *parse_va_arg(void)
6471 {
6472         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6473
6474         eat(T___builtin_va_arg);
6475
6476         add_anchor_token(')');
6477         add_anchor_token(',');
6478         expect('(');
6479         call_argument_t ap;
6480         ap.expression = parse_assignment_expression();
6481         expression->va_arge.ap = ap.expression;
6482         check_call_argument(type_valist, &ap, 1);
6483
6484         rem_anchor_token(',');
6485         expect(',');
6486         expression->base.type = parse_typename();
6487         rem_anchor_token(')');
6488         expect(')');
6489
6490         return expression;
6491 }
6492
6493 /**
6494  * Parses a __builtin_va_copy() expression.
6495  */
6496 static expression_t *parse_va_copy(void)
6497 {
6498         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6499
6500         eat(T___builtin_va_copy);
6501
6502         add_anchor_token(')');
6503         add_anchor_token(',');
6504         expect('(');
6505         expression_t *dst = parse_assignment_expression();
6506         assign_error_t error = semantic_assign(type_valist, dst);
6507         report_assign_error(error, type_valist, dst, "call argument 1",
6508                             &dst->base.pos);
6509         expression->va_copye.dst = dst;
6510
6511         rem_anchor_token(',');
6512         expect(',');
6513
6514         call_argument_t src;
6515         src.expression = parse_assignment_expression();
6516         check_call_argument(type_valist, &src, 2);
6517         expression->va_copye.src = src.expression;
6518         rem_anchor_token(')');
6519         expect(')');
6520
6521         return expression;
6522 }
6523
6524 /**
6525  * Parses a __builtin_constant_p() expression.
6526  */
6527 static expression_t *parse_builtin_constant(void)
6528 {
6529         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6530
6531         eat(T___builtin_constant_p);
6532
6533         add_anchor_token(')');
6534         expect('(');
6535         expression->builtin_constant.value = parse_expression();
6536         rem_anchor_token(')');
6537         expect(')');
6538         expression->base.type = type_int;
6539
6540         return expression;
6541 }
6542
6543 /**
6544  * Parses a __builtin_types_compatible_p() expression.
6545  */
6546 static expression_t *parse_builtin_types_compatible(void)
6547 {
6548         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6549
6550         eat(T___builtin_types_compatible_p);
6551
6552         add_anchor_token(')');
6553         add_anchor_token(',');
6554         expect('(');
6555         expression->builtin_types_compatible.left = parse_typename();
6556         rem_anchor_token(',');
6557         expect(',');
6558         expression->builtin_types_compatible.right = parse_typename();
6559         rem_anchor_token(')');
6560         expect(')');
6561         expression->base.type = type_int;
6562
6563         return expression;
6564 }
6565
6566 /**
6567  * Parses a __builtin_is_*() compare expression.
6568  */
6569 static expression_t *parse_compare_builtin(void)
6570 {
6571         expression_kind_t kind;
6572         switch (token.kind) {
6573         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6574         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6575         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6576         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6577         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6578         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6579         default: internal_errorf(HERE, "invalid compare builtin found");
6580         }
6581         expression_t *const expression = allocate_expression_zero(kind);
6582         next_token();
6583
6584         add_anchor_token(')');
6585         add_anchor_token(',');
6586         expect('(');
6587         expression->binary.left = parse_assignment_expression();
6588         rem_anchor_token(',');
6589         expect(',');
6590         expression->binary.right = parse_assignment_expression();
6591         rem_anchor_token(')');
6592         expect(')');
6593
6594         type_t *const orig_type_left  = expression->binary.left->base.type;
6595         type_t *const orig_type_right = expression->binary.right->base.type;
6596
6597         type_t *const type_left  = skip_typeref(orig_type_left);
6598         type_t *const type_right = skip_typeref(orig_type_right);
6599         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6600                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6601                         type_error_incompatible("invalid operands in comparison",
6602                                 &expression->base.pos, orig_type_left, orig_type_right);
6603                 }
6604         } else {
6605                 semantic_comparison(&expression->binary, true);
6606         }
6607
6608         return expression;
6609 }
6610
6611 /**
6612  * Parses a MS assume() expression.
6613  */
6614 static expression_t *parse_assume(void)
6615 {
6616         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6617
6618         eat(T__assume);
6619
6620         add_anchor_token(')');
6621         expect('(');
6622         expression->unary.value = parse_expression();
6623         rem_anchor_token(')');
6624         expect(')');
6625
6626         expression->base.type = type_void;
6627         return expression;
6628 }
6629
6630 /**
6631  * Return the label for the current symbol or create a new one.
6632  */
6633 static label_t *get_label(char const *const context)
6634 {
6635         assert(current_function != NULL);
6636
6637         symbol_t *const sym = expect_identifier(context, NULL);
6638         if (!sym)
6639                 return NULL;
6640
6641         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6642         /* If we find a local label, we already created the declaration. */
6643         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6644                 if (label->base.parent_scope != current_scope) {
6645                         assert(label->base.parent_scope->depth < current_scope->depth);
6646                         current_function->goto_to_outer = true;
6647                 }
6648         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6649                 /* There is no matching label in the same function, so create a new one. */
6650                 position_t const nowhere = { NULL, 0, 0, false };
6651                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6652                 label_push(label);
6653         }
6654
6655         return &label->label;
6656 }
6657
6658 /**
6659  * Parses a GNU && label address expression.
6660  */
6661 static expression_t *parse_label_address(void)
6662 {
6663         position_t const pos = *HERE;
6664         eat(T_ANDAND);
6665
6666         label_t *const label = get_label("while parsing label address");
6667         if (!label)
6668                 return create_error_expression();
6669
6670         label->used          = true;
6671         label->address_taken = true;
6672
6673         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6674         expression->base.pos     = pos;
6675
6676         /* label address is treated as a void pointer */
6677         expression->base.type           = type_void_ptr;
6678         expression->label_address.label = label;
6679         return expression;
6680 }
6681
6682 /**
6683  * Parse a microsoft __noop expression.
6684  */
6685 static expression_t *parse_noop_expression(void)
6686 {
6687         /* the result is a (int)0 */
6688         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6689         literal->base.type           = type_int;
6690         literal->literal.value.begin = "__noop";
6691         literal->literal.value.size  = 6;
6692
6693         eat(T___noop);
6694
6695         if (token.kind == '(') {
6696                 /* parse arguments */
6697                 eat('(');
6698                 add_anchor_token(')');
6699                 add_anchor_token(',');
6700
6701                 if (token.kind != ')') do {
6702                         (void)parse_assignment_expression();
6703                 } while (accept(','));
6704
6705                 rem_anchor_token(',');
6706                 rem_anchor_token(')');
6707         }
6708         expect(')');
6709
6710         return literal;
6711 }
6712
6713 /**
6714  * Parses a primary expression.
6715  */
6716 static expression_t *parse_primary_expression(void)
6717 {
6718         switch (token.kind) {
6719         case T_false:                        return parse_boolean_literal(false);
6720         case T_true:                         return parse_boolean_literal(true);
6721         case T_NUMBER:                       return parse_number_literal();
6722         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6723         case T_STRING_LITERAL:               return parse_string_literal();
6724         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6725         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6726         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6727         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6728         case T___builtin_offsetof:           return parse_offsetof();
6729         case T___builtin_va_start:           return parse_va_start();
6730         case T___builtin_va_arg:             return parse_va_arg();
6731         case T___builtin_va_copy:            return parse_va_copy();
6732         case T___builtin_isgreater:
6733         case T___builtin_isgreaterequal:
6734         case T___builtin_isless:
6735         case T___builtin_islessequal:
6736         case T___builtin_islessgreater:
6737         case T___builtin_isunordered:        return parse_compare_builtin();
6738         case T___builtin_constant_p:         return parse_builtin_constant();
6739         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6740         case T__assume:                      return parse_assume();
6741         case T_ANDAND:
6742                 if (GNU_MODE)
6743                         return parse_label_address();
6744                 break;
6745
6746         case '(':                            return parse_parenthesized_expression();
6747         case T___noop:                       return parse_noop_expression();
6748         case T___imag__:                     return parse_complex_extract_expression(EXPR_UNARY_IMAG);
6749         case T___real__:                     return parse_complex_extract_expression(EXPR_UNARY_REAL);
6750
6751         /* Gracefully handle type names while parsing expressions. */
6752         case T_COLONCOLON:
6753                 return parse_reference();
6754         case T_IDENTIFIER:
6755                 if (!is_typedef_symbol(token.base.symbol)) {
6756                         return parse_reference();
6757                 }
6758                 /* FALLTHROUGH */
6759         DECLARATION_START {
6760                 position_t const pos = *HERE;
6761                 declaration_specifiers_t specifiers;
6762                 parse_declaration_specifiers(&specifiers);
6763                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6764                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6765                 return create_error_expression();
6766         }
6767         }
6768
6769         errorf(HERE, "unexpected token %K, expected an expression", &token);
6770         eat_until_anchor();
6771         return create_error_expression();
6772 }
6773
6774 static expression_t *parse_array_expression(expression_t *left)
6775 {
6776         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6777         array_access_expression_t *const arr  = &expr->array_access;
6778
6779         eat('[');
6780         add_anchor_token(']');
6781
6782         expression_t *const inside = parse_expression();
6783
6784         type_t *const orig_type_left   = left->base.type;
6785         type_t *const orig_type_inside = inside->base.type;
6786
6787         type_t *const type_left   = skip_typeref(orig_type_left);
6788         type_t *const type_inside = skip_typeref(orig_type_inside);
6789
6790         expression_t *ref;
6791         expression_t *idx;
6792         type_t       *idx_type;
6793         type_t       *res_type;
6794         if (is_type_pointer(type_left)) {
6795                 ref      = left;
6796                 idx      = inside;
6797                 idx_type = type_inside;
6798                 res_type = type_left->pointer.points_to;
6799                 goto check_idx;
6800         } else if (is_type_pointer(type_inside)) {
6801                 arr->flipped = true;
6802                 ref      = inside;
6803                 idx      = left;
6804                 idx_type = type_left;
6805                 res_type = type_inside->pointer.points_to;
6806 check_idx:
6807                 res_type = automatic_type_conversion(res_type);
6808                 if (!is_type_integer(idx_type)) {
6809                         if (is_type_valid(idx_type))
6810                                 errorf(&idx->base.pos, "array subscript must have integer type");
6811                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6812                         position_t const *const pos = &idx->base.pos;
6813                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6814                 }
6815         } else {
6816                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6817                         errorf(&expr->base.pos, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6818                 }
6819                 res_type = type_error_type;
6820                 ref      = left;
6821                 idx      = inside;
6822         }
6823
6824         arr->array_ref = ref;
6825         arr->index     = idx;
6826         arr->base.type = res_type;
6827
6828         rem_anchor_token(']');
6829         expect(']');
6830         return expr;
6831 }
6832
6833 static bool is_bitfield(const expression_t *expression)
6834 {
6835         return expression->kind == EXPR_SELECT
6836                 && expression->select.compound_entry->compound_member.bitfield;
6837 }
6838
6839 static expression_t *parse_typeprop(expression_kind_t const kind)
6840 {
6841         expression_t  *tp_expression = allocate_expression_zero(kind);
6842         tp_expression->base.type     = type_size_t;
6843
6844         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6845
6846         type_t       *orig_type;
6847         expression_t *expression;
6848         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6849                 position_t const pos = *HERE;
6850                 eat('(');
6851                 add_anchor_token(')');
6852                 orig_type = parse_typename();
6853                 rem_anchor_token(')');
6854                 expect(')');
6855
6856                 if (token.kind == '{') {
6857                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6858                          * starting with a compound literal */
6859                         expression = parse_compound_literal(&pos, orig_type);
6860                         goto typeprop_expression;
6861                 }
6862         } else {
6863                 expression = parse_subexpression(PREC_UNARY);
6864
6865 typeprop_expression:
6866                 if (is_bitfield(expression)) {
6867                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6868                         errorf(&tp_expression->base.pos,
6869                                    "operand of %s expression must not be a bitfield", what);
6870                 }
6871
6872                 tp_expression->typeprop.tp_expression = expression;
6873
6874                 orig_type = revert_automatic_type_conversion(expression);
6875                 expression->base.type = orig_type;
6876         }
6877
6878         tp_expression->typeprop.type   = orig_type;
6879         type_t const* const type       = skip_typeref(orig_type);
6880         char   const*       wrong_type = NULL;
6881         if (is_type_incomplete(type)) {
6882                 if (!is_type_void(type) || !GNU_MODE)
6883                         wrong_type = "incomplete";
6884         } else if (type->kind == TYPE_FUNCTION) {
6885                 if (GNU_MODE) {
6886                         /* function types are allowed (and return 1) */
6887                         position_t const *const pos  = &tp_expression->base.pos;
6888                         char       const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6889                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6890                 } else {
6891                         wrong_type = "function";
6892                 }
6893         }
6894
6895         if (wrong_type != NULL) {
6896                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6897                 errorf(&tp_expression->base.pos,
6898                                 "operand of %s expression must not be of %s type '%T'",
6899                                 what, wrong_type, orig_type);
6900         }
6901
6902         return tp_expression;
6903 }
6904
6905 static expression_t *parse_sizeof(void)
6906 {
6907         return parse_typeprop(EXPR_SIZEOF);
6908 }
6909
6910 static expression_t *parse_alignof(void)
6911 {
6912         return parse_typeprop(EXPR_ALIGNOF);
6913 }
6914
6915 static expression_t *parse_select_expression(expression_t *addr)
6916 {
6917         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6918         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6919         position_t const pos = *HERE;
6920         next_token();
6921
6922         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6923         if (!symbol)
6924                 return create_error_expression();
6925
6926         type_t *const orig_type = addr->base.type;
6927         type_t *const type      = skip_typeref(orig_type);
6928
6929         type_t *type_left;
6930         bool    saw_error = false;
6931         if (is_type_pointer(type)) {
6932                 if (!select_left_arrow) {
6933                         errorf(&pos,
6934                                "request for member '%Y' in something not a struct or union, but '%T'",
6935                                symbol, orig_type);
6936                         saw_error = true;
6937                 }
6938                 type_left = skip_typeref(type->pointer.points_to);
6939         } else {
6940                 if (select_left_arrow && is_type_valid(type)) {
6941                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6942                         saw_error = true;
6943                 }
6944                 type_left = type;
6945         }
6946
6947         if (!is_type_compound(type_left)) {
6948                 if (is_type_valid(type_left) && !saw_error) {
6949                         errorf(&pos,
6950                                "request for member '%Y' in something not a struct or union, but '%T'",
6951                                symbol, type_left);
6952                 }
6953                 return create_error_expression();
6954         }
6955
6956         compound_t *compound = type_left->compound.compound;
6957         if (!compound->complete) {
6958                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6959                        symbol, type_left);
6960                 return create_error_expression();
6961         }
6962
6963         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6964         expression_t      *result     =
6965                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6966
6967         if (result == NULL) {
6968                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6969                 return create_error_expression();
6970         }
6971
6972         return result;
6973 }
6974
6975 static void check_call_argument(type_t          *expected_type,
6976                                 call_argument_t *argument, unsigned pos)
6977 {
6978         type_t         *expected_type_skip = skip_typeref(expected_type);
6979         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6980         expression_t   *arg_expr           = argument->expression;
6981         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6982
6983         /* handle transparent union gnu extension */
6984         if (is_type_union(expected_type_skip)
6985                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6986                 compound_t *union_decl  = expected_type_skip->compound.compound;
6987                 type_t     *best_type   = NULL;
6988                 entity_t   *entry       = union_decl->members.entities;
6989                 for ( ; entry != NULL; entry = entry->base.next) {
6990                         assert(is_declaration(entry));
6991                         type_t *decl_type = entry->declaration.type;
6992                         error = semantic_assign(decl_type, arg_expr);
6993                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6994                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6995                                 continue;
6996
6997                         if (error == ASSIGN_SUCCESS) {
6998                                 best_type = decl_type;
6999                         } else if (best_type == NULL) {
7000                                 best_type = decl_type;
7001                         }
7002                 }
7003
7004                 if (best_type != NULL) {
7005                         expected_type = best_type;
7006                 }
7007         }
7008
7009         error                = semantic_assign(expected_type, arg_expr);
7010         argument->expression = create_implicit_cast(arg_expr, expected_type);
7011
7012         if (error != ASSIGN_SUCCESS) {
7013                 /* report exact scope in error messages (like "in argument 3") */
7014                 char buf[64];
7015                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7016                 report_assign_error(error, expected_type, arg_expr, buf,
7017                                     &arg_expr->base.pos);
7018         } else {
7019                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7020                 if (!types_compatible(expected_type_skip, promoted_type) &&
7021                     !types_compatible(expected_type_skip, type_void_ptr) &&
7022                     !types_compatible(type_void_ptr,      promoted_type)) {
7023                         /* Deliberately show the skipped types in this warning */
7024                         position_t const *const apos = &arg_expr->base.pos;
7025                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7026                 }
7027         }
7028 }
7029
7030 /**
7031  * Handle the semantic restrictions of builtin calls
7032  */
7033 static void handle_builtin_argument_restrictions(call_expression_t *call)
7034 {
7035         entity_t *entity = call->function->reference.entity;
7036         switch (entity->function.btk) {
7037         case BUILTIN_FIRM:
7038                 switch (entity->function.b.firm_builtin_kind) {
7039                 case ir_bk_return_address:
7040                 case ir_bk_frame_address: {
7041                         /* argument must be constant */
7042                         call_argument_t *argument = call->arguments;
7043
7044                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7045                                 errorf(&call->base.pos,
7046                                            "argument of '%Y' must be a constant expression",
7047                                            call->function->reference.entity->base.symbol);
7048                         }
7049                         break;
7050                 }
7051                 case ir_bk_prefetch:
7052                         /* second and third argument must be constant if existent */
7053                         if (call->arguments == NULL)
7054                                 break;
7055                         call_argument_t *rw = call->arguments->next;
7056                         call_argument_t *locality = NULL;
7057
7058                         if (rw != NULL) {
7059                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7060                                         errorf(&call->base.pos,
7061                                                    "second argument of '%Y' must be a constant expression",
7062                                                    call->function->reference.entity->base.symbol);
7063                                 }
7064                                 locality = rw->next;
7065                         }
7066                         if (locality != NULL) {
7067                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7068                                         errorf(&call->base.pos,
7069                                                    "third argument of '%Y' must be a constant expression",
7070                                                    call->function->reference.entity->base.symbol);
7071                                 }
7072                         }
7073                         break;
7074                 default:
7075                         break;
7076                 }
7077
7078         case BUILTIN_OBJECT_SIZE:
7079                 if (call->arguments == NULL)
7080                         break;
7081
7082                 call_argument_t *arg = call->arguments->next;
7083                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7084                         errorf(&call->base.pos,
7085                                    "second argument of '%Y' must be a constant expression",
7086                                    call->function->reference.entity->base.symbol);
7087                 }
7088                 break;
7089         default:
7090                 break;
7091         }
7092 }
7093
7094 /**
7095  * Parse a call expression, i.e. expression '( ... )'.
7096  *
7097  * @param expression  the function address
7098  */
7099 static expression_t *parse_call_expression(expression_t *expression)
7100 {
7101         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7102         call_expression_t *call   = &result->call;
7103         call->function            = expression;
7104
7105         type_t *const orig_type = expression->base.type;
7106         type_t *const type      = skip_typeref(orig_type);
7107
7108         function_type_t *function_type = NULL;
7109         if (is_type_pointer(type)) {
7110                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7111
7112                 if (is_type_function(to_type)) {
7113                         function_type   = &to_type->function;
7114                         call->base.type = function_type->return_type;
7115                 }
7116         }
7117
7118         if (function_type == NULL && is_type_valid(type)) {
7119                 errorf(HERE,
7120                        "called object '%E' (type '%T') is not a pointer to a function",
7121                        expression, orig_type);
7122         }
7123
7124         /* parse arguments */
7125         eat('(');
7126         add_anchor_token(')');
7127         add_anchor_token(',');
7128
7129         if (token.kind != ')') {
7130                 call_argument_t **anchor = &call->arguments;
7131                 do {
7132                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7133                         argument->expression = parse_assignment_expression();
7134
7135                         *anchor = argument;
7136                         anchor  = &argument->next;
7137                 } while (accept(','));
7138         }
7139         rem_anchor_token(',');
7140         rem_anchor_token(')');
7141         expect(')');
7142
7143         if (function_type == NULL)
7144                 return result;
7145
7146         /* check type and count of call arguments */
7147         function_parameter_t *parameter = function_type->parameters;
7148         call_argument_t      *argument  = call->arguments;
7149         if (!function_type->unspecified_parameters) {
7150                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7151                                 parameter = parameter->next, argument = argument->next) {
7152                         check_call_argument(parameter->type, argument, ++pos);
7153                 }
7154
7155                 if (parameter != NULL) {
7156                         errorf(&expression->base.pos, "too few arguments to function '%E'",
7157                                expression);
7158                 } else if (argument != NULL && !function_type->variadic) {
7159                         errorf(&argument->expression->base.pos,
7160                                "too many arguments to function '%E'", expression);
7161                 }
7162         }
7163
7164         /* do default promotion for other arguments */
7165         for (; argument != NULL; argument = argument->next) {
7166                 type_t *argument_type = argument->expression->base.type;
7167                 if (!is_type_object(skip_typeref(argument_type))) {
7168                         errorf(&argument->expression->base.pos,
7169                                "call argument '%E' must not be void", argument->expression);
7170                 }
7171
7172                 argument_type = get_default_promoted_type(argument_type);
7173
7174                 argument->expression
7175                         = create_implicit_cast(argument->expression, argument_type);
7176         }
7177
7178         check_format(call);
7179
7180         if (is_type_compound(skip_typeref(function_type->return_type))) {
7181                 position_t const *const pos = &expression->base.pos;
7182                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7183         }
7184
7185         if (expression->kind == EXPR_REFERENCE) {
7186                 reference_expression_t *reference = &expression->reference;
7187                 if (reference->entity->kind == ENTITY_FUNCTION &&
7188                     reference->entity->function.btk != BUILTIN_NONE)
7189                         handle_builtin_argument_restrictions(call);
7190         }
7191
7192         return result;
7193 }
7194
7195 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7196
7197 static bool same_compound_type(const type_t *type1, const type_t *type2)
7198 {
7199         return
7200                 is_type_compound(type1) &&
7201                 type1->kind == type2->kind &&
7202                 type1->compound.compound == type2->compound.compound;
7203 }
7204
7205 static expression_t const *get_reference_address(expression_t const *expr)
7206 {
7207         bool regular_take_address = true;
7208         for (;;) {
7209                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7210                         expr = expr->unary.value;
7211                 } else {
7212                         regular_take_address = false;
7213                 }
7214
7215                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7216                         break;
7217
7218                 expr = expr->unary.value;
7219         }
7220
7221         if (expr->kind != EXPR_REFERENCE)
7222                 return NULL;
7223
7224         /* special case for functions which are automatically converted to a
7225          * pointer to function without an extra TAKE_ADDRESS operation */
7226         if (!regular_take_address &&
7227                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7228                 return NULL;
7229         }
7230
7231         return expr;
7232 }
7233
7234 static void warn_reference_address_as_bool(expression_t const* expr)
7235 {
7236         expr = get_reference_address(expr);
7237         if (expr != NULL) {
7238                 position_t const *const pos = &expr->base.pos;
7239                 entity_t   const *const ent = expr->reference.entity;
7240                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7241         }
7242 }
7243
7244 static void warn_assignment_in_condition(const expression_t *const expr)
7245 {
7246         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7247                 return;
7248         if (expr->base.parenthesized)
7249                 return;
7250         position_t const *const pos = &expr->base.pos;
7251         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7252 }
7253
7254 static void semantic_condition(expression_t const *const expr,
7255                                char const *const context)
7256 {
7257         type_t *const type = skip_typeref(expr->base.type);
7258         if (is_type_scalar(type)) {
7259                 warn_reference_address_as_bool(expr);
7260                 warn_assignment_in_condition(expr);
7261         } else if (is_type_valid(type)) {
7262                 errorf(&expr->base.pos, "%s must have scalar type", context);
7263         }
7264 }
7265
7266 /**
7267  * Parse a conditional expression, i.e. 'expression ? ... : ...'.
7268  *
7269  * @param expression  the conditional expression
7270  */
7271 static expression_t *parse_conditional_expression(expression_t *expression)
7272 {
7273         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7274
7275         conditional_expression_t *conditional = &result->conditional;
7276         conditional->condition                = expression;
7277
7278         eat('?');
7279         add_anchor_token(':');
7280
7281         /* §6.5.15:2  The first operand shall have scalar type. */
7282         semantic_condition(expression, "condition of conditional operator");
7283
7284         expression_t *true_expression = expression;
7285         bool          gnu_cond = false;
7286         if (GNU_MODE && token.kind == ':') {
7287                 gnu_cond = true;
7288         } else {
7289                 true_expression = parse_expression();
7290         }
7291         rem_anchor_token(':');
7292         expect(':');
7293         expression_t *false_expression =
7294                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7295
7296         type_t *const orig_true_type  = true_expression->base.type;
7297         type_t *const orig_false_type = false_expression->base.type;
7298         type_t *const true_type       = skip_typeref(orig_true_type);
7299         type_t *const false_type      = skip_typeref(orig_false_type);
7300
7301         /* 6.5.15.3 */
7302         position_t const *const pos = &conditional->base.pos;
7303         type_t                 *result_type;
7304         if (is_type_void(true_type) || is_type_void(false_type)) {
7305                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7306                 if (true_expression->kind == EXPR_UNARY_THROW) {
7307                         result_type = false_type;
7308                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7309                         result_type = true_type;
7310                 } else {
7311                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7312                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7313                         }
7314                         result_type = type_void;
7315                 }
7316         } else if (is_type_arithmetic(true_type)
7317                    && is_type_arithmetic(false_type)) {
7318                 result_type = semantic_arithmetic(true_type, false_type);
7319         } else if (same_compound_type(true_type, false_type)) {
7320                 /* just take 1 of the 2 types */
7321                 result_type = true_type;
7322         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7323                 type_t *pointer_type;
7324                 type_t *other_type;
7325                 expression_t *other_expression;
7326                 if (is_type_pointer(true_type) &&
7327                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7328                         pointer_type     = true_type;
7329                         other_type       = false_type;
7330                         other_expression = false_expression;
7331                 } else {
7332                         pointer_type     = false_type;
7333                         other_type       = true_type;
7334                         other_expression = true_expression;
7335                 }
7336
7337                 if (is_null_pointer_constant(other_expression)) {
7338                         result_type = pointer_type;
7339                 } else if (is_type_pointer(other_type)) {
7340                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7341                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7342
7343                         type_t *to;
7344                         if (is_type_void(to1) || is_type_void(to2)) {
7345                                 to = type_void;
7346                         } else if (types_compatible(get_unqualified_type(to1),
7347                                                     get_unqualified_type(to2))) {
7348                                 to = to1;
7349                         } else {
7350                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7351                                 to = type_void;
7352                         }
7353
7354                         type_t *const type =
7355                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7356                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7357                 } else if (is_type_integer(other_type)) {
7358                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7359                         result_type = pointer_type;
7360                 } else {
7361                         goto types_incompatible;
7362                 }
7363         } else {
7364 types_incompatible:
7365                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7366                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7367                 }
7368                 result_type = type_error_type;
7369         }
7370
7371         conditional->true_expression
7372                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7373         conditional->false_expression
7374                 = create_implicit_cast(false_expression, result_type);
7375         conditional->base.type = result_type;
7376         return result;
7377 }
7378
7379 /**
7380  * Parse an extension expression.
7381  */
7382 static expression_t *parse_extension(void)
7383 {
7384         PUSH_EXTENSION();
7385         expression_t *expression = parse_subexpression(PREC_UNARY);
7386         POP_EXTENSION();
7387         return expression;
7388 }
7389
7390 /**
7391  * Parse a __builtin_classify_type() expression.
7392  */
7393 static expression_t *parse_builtin_classify_type(void)
7394 {
7395         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7396         result->base.type    = type_int;
7397
7398         eat(T___builtin_classify_type);
7399
7400         add_anchor_token(')');
7401         expect('(');
7402         expression_t *expression = parse_expression();
7403         rem_anchor_token(')');
7404         expect(')');
7405         result->classify_type.type_expression = expression;
7406
7407         return result;
7408 }
7409
7410 /**
7411  * Parse a delete expression
7412  * ISO/IEC 14882:1998(E) §5.3.5
7413  */
7414 static expression_t *parse_delete(void)
7415 {
7416         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7417         result->base.type          = type_void;
7418
7419         eat(T_delete);
7420
7421         if (accept('[')) {
7422                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7423                 expect(']');
7424         }
7425
7426         expression_t *const value = parse_subexpression(PREC_CAST);
7427         result->unary.value = value;
7428
7429         type_t *const type = skip_typeref(value->base.type);
7430         if (!is_type_pointer(type)) {
7431                 if (is_type_valid(type)) {
7432                         errorf(&value->base.pos,
7433                                         "operand of delete must have pointer type");
7434                 }
7435         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7436                 position_t const *const pos = &value->base.pos;
7437                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7438         }
7439
7440         return result;
7441 }
7442
7443 /**
7444  * Parse a throw expression
7445  * ISO/IEC 14882:1998(E) §15:1
7446  */
7447 static expression_t *parse_throw(void)
7448 {
7449         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7450         result->base.type          = type_void;
7451
7452         eat(T_throw);
7453
7454         expression_t *value = NULL;
7455         switch (token.kind) {
7456                 EXPRESSION_START {
7457                         value = parse_assignment_expression();
7458                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7459                         type_t *const orig_type = value->base.type;
7460                         type_t *const type      = skip_typeref(orig_type);
7461                         if (is_type_incomplete(type)) {
7462                                 errorf(&value->base.pos,
7463                                                 "cannot throw object of incomplete type '%T'", orig_type);
7464                         } else if (is_type_pointer(type)) {
7465                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7466                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7467                                         errorf(&value->base.pos,
7468                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7469                                 }
7470                         }
7471                 }
7472
7473                 default:
7474                         break;
7475         }
7476         result->unary.value = value;
7477
7478         return result;
7479 }
7480
7481 static bool check_pointer_arithmetic(const position_t *pos,
7482                                      type_t *pointer_type,
7483                                      type_t *orig_pointer_type)
7484 {
7485         type_t *points_to = pointer_type->pointer.points_to;
7486         points_to = skip_typeref(points_to);
7487
7488         if (is_type_incomplete(points_to)) {
7489                 if (!GNU_MODE || !is_type_void(points_to)) {
7490                         errorf(pos,
7491                                "arithmetic with pointer to incomplete type '%T' not allowed",
7492                                orig_pointer_type);
7493                         return false;
7494                 } else {
7495                         warningf(WARN_POINTER_ARITH, pos, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7496                 }
7497         } else if (is_type_function(points_to)) {
7498                 if (!GNU_MODE) {
7499                         errorf(pos,
7500                                "arithmetic with pointer to function type '%T' not allowed",
7501                                orig_pointer_type);
7502                         return false;
7503                 } else {
7504                         warningf(WARN_POINTER_ARITH, pos,
7505                                  "pointer to a function '%T' used in arithmetic",
7506                                  orig_pointer_type);
7507                 }
7508         }
7509         return true;
7510 }
7511
7512 static bool is_lvalue(const expression_t *expression)
7513 {
7514         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7515         switch (expression->kind) {
7516         case EXPR_ARRAY_ACCESS:
7517         case EXPR_COMPOUND_LITERAL:
7518         case EXPR_REFERENCE:
7519         case EXPR_SELECT:
7520         case EXPR_UNARY_DEREFERENCE:
7521                 return true;
7522
7523         default: {
7524                 type_t *type = skip_typeref(expression->base.type);
7525                 return
7526                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7527                         is_type_reference(type) ||
7528                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7529                          * error before, which maybe prevented properly recognizing it as
7530                          * lvalue. */
7531                         !is_type_valid(type);
7532         }
7533         }
7534 }
7535
7536 static void semantic_incdec(unary_expression_t *expression)
7537 {
7538         type_t *orig_type = expression->value->base.type;
7539         type_t *type      = skip_typeref(orig_type);
7540         if (is_type_pointer(type)) {
7541                 if (!check_pointer_arithmetic(&expression->base.pos, type, orig_type)) {
7542                         return;
7543                 }
7544         } else if (!is_type_real(type) &&
7545                    (!GNU_MODE || !is_type_complex(type)) && is_type_valid(type)) {
7546                 /* TODO: improve error message */
7547                 errorf(&expression->base.pos,
7548                        "operation needs an arithmetic or pointer type");
7549                 orig_type = type = type_error_type;
7550         }
7551         if (!is_lvalue(expression->value)) {
7552                 /* TODO: improve error message */
7553                 errorf(&expression->base.pos, "lvalue required as operand");
7554         }
7555         expression->base.type = orig_type;
7556 }
7557
7558 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7559 {
7560         atomic_type_kind_t akind = get_arithmetic_akind(type);
7561         type_t *res_type;
7562         if (get_akind_rank(akind) < get_akind_rank(ATOMIC_TYPE_INT)) {
7563                 if (type->kind == TYPE_COMPLEX)
7564                         res_type = make_complex_type(ATOMIC_TYPE_INT, TYPE_QUALIFIER_NONE);
7565                 else
7566                         res_type = type_int;
7567         } else {
7568                 res_type = type;
7569         }
7570         expr->base.type = res_type;
7571         expr->value     = create_implicit_cast(expr->value, res_type);
7572 }
7573
7574 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7575 {
7576         type_t *const orig_type = expression->value->base.type;
7577         type_t *const type      = skip_typeref(orig_type);
7578         if (!is_type_arithmetic(type)) {
7579                 if (is_type_valid(type)) {
7580                         position_t const *const pos = &expression->base.pos;
7581                         errorf(pos, "operand of unary expression must have arithmetic type, but is '%T'", orig_type);
7582                 }
7583                 return;
7584         } else if (is_type_integer(type)) {
7585                 promote_unary_int_expr(expression, type);
7586         } else {
7587                 expression->base.type = orig_type;
7588         }
7589 }
7590
7591 static void semantic_unexpr_plus(unary_expression_t *expression)
7592 {
7593         semantic_unexpr_arithmetic(expression);
7594         position_t const *const pos = &expression->base.pos;
7595         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7596 }
7597
7598 static void semantic_not(unary_expression_t *expression)
7599 {
7600         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7601         semantic_condition(expression->value, "operand of !");
7602         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7603 }
7604
7605 static void semantic_complement(unary_expression_t *expression)
7606 {
7607         type_t *const orig_type = expression->value->base.type;
7608         type_t *const type      = skip_typeref(orig_type);
7609         if (!is_type_integer(type) && (!GNU_MODE || !is_type_complex(type))) {
7610                 if (is_type_valid(type)) {
7611                         errorf(&expression->base.pos, "operand of ~ must be of integer type");
7612                 }
7613                 return;
7614         }
7615
7616         if (is_type_integer(type)) {
7617                 promote_unary_int_expr(expression, type);
7618         } else {
7619                 expression->base.type = orig_type;
7620         }
7621 }
7622
7623 static void semantic_dereference(unary_expression_t *expression)
7624 {
7625         type_t *const orig_type = expression->value->base.type;
7626         type_t *const type      = skip_typeref(orig_type);
7627         if (!is_type_pointer(type)) {
7628                 if (is_type_valid(type)) {
7629                         errorf(&expression->base.pos,
7630                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7631                 }
7632                 return;
7633         }
7634
7635         type_t *result_type   = type->pointer.points_to;
7636         result_type           = automatic_type_conversion(result_type);
7637         expression->base.type = result_type;
7638 }
7639
7640 /**
7641  * Record that an address is taken (expression represents an lvalue).
7642  *
7643  * @param expression       the expression
7644  * @param may_be_register  if true, the expression might be an register
7645  */
7646 static void set_address_taken(expression_t *expression, bool may_be_register)
7647 {
7648         if (expression->kind != EXPR_REFERENCE)
7649                 return;
7650
7651         entity_t *const entity = expression->reference.entity;
7652
7653         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7654                 return;
7655
7656         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7657                         && !may_be_register) {
7658                 position_t const *const pos = &expression->base.pos;
7659                 errorf(pos, "address of register '%N' requested", entity);
7660         }
7661
7662         entity->variable.address_taken = true;
7663 }
7664
7665 /**
7666  * Check the semantic of the address taken expression.
7667  */
7668 static void semantic_take_addr(unary_expression_t *expression)
7669 {
7670         expression_t *value = expression->value;
7671         value->base.type    = revert_automatic_type_conversion(value);
7672
7673         type_t *orig_type = value->base.type;
7674         type_t *type      = skip_typeref(orig_type);
7675         if (!is_type_valid(type))
7676                 return;
7677
7678         /* §6.5.3.2 */
7679         if (!is_lvalue(value)) {
7680                 errorf(&expression->base.pos, "'&' requires an lvalue");
7681         }
7682         if (is_bitfield(value)) {
7683                 errorf(&expression->base.pos, "'&' not allowed on bitfield");
7684         }
7685
7686         set_address_taken(value, false);
7687
7688         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7689 }
7690
7691 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7692 static expression_t *parse_##unexpression_type(void)                         \
7693 {                                                                            \
7694         expression_t *unary_expression                                           \
7695                 = allocate_expression_zero(unexpression_type);                       \
7696         eat(token_kind);                                                         \
7697         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7698                                                                                  \
7699         sfunc(&unary_expression->unary);                                         \
7700                                                                                  \
7701         return unary_expression;                                                 \
7702 }
7703
7704 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7705                                semantic_unexpr_arithmetic)
7706 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7707                                semantic_unexpr_plus)
7708 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7709                                semantic_not)
7710 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7711                                semantic_dereference)
7712 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7713                                semantic_take_addr)
7714 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_COMPLEMENT,
7715                                semantic_complement)
7716 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7717                                semantic_incdec)
7718 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7719                                semantic_incdec)
7720
7721 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7722                                                sfunc)                         \
7723 static expression_t *parse_##unexpression_type(expression_t *left)            \
7724 {                                                                             \
7725         expression_t *unary_expression                                            \
7726                 = allocate_expression_zero(unexpression_type);                        \
7727         eat(token_kind);                                                          \
7728         unary_expression->unary.value = left;                                     \
7729                                                                                   \
7730         sfunc(&unary_expression->unary);                                          \
7731                                                                               \
7732         return unary_expression;                                                  \
7733 }
7734
7735 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7736                                        EXPR_UNARY_POSTFIX_INCREMENT,
7737                                        semantic_incdec)
7738 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7739                                        EXPR_UNARY_POSTFIX_DECREMENT,
7740                                        semantic_incdec)
7741
7742 static atomic_type_kind_t semantic_arithmetic_(atomic_type_kind_t kind_left,
7743                                                atomic_type_kind_t kind_right)
7744 {
7745         /* §6.3.1.8 Usual arithmetic conversions */
7746         if (kind_left == ATOMIC_TYPE_LONG_DOUBLE
7747          || kind_right == ATOMIC_TYPE_LONG_DOUBLE) {
7748                 return ATOMIC_TYPE_LONG_DOUBLE;
7749         } else if (kind_left == ATOMIC_TYPE_DOUBLE
7750                 || kind_right == ATOMIC_TYPE_DOUBLE) {
7751             return ATOMIC_TYPE_DOUBLE;
7752         } else if (kind_left == ATOMIC_TYPE_FLOAT
7753                 || kind_right == ATOMIC_TYPE_FLOAT) {
7754                 return ATOMIC_TYPE_FLOAT;
7755         }
7756
7757         unsigned       rank_left  = get_akind_rank(kind_left);
7758         unsigned       rank_right = get_akind_rank(kind_right);
7759         unsigned const rank_int   = get_akind_rank(ATOMIC_TYPE_INT);
7760         if (rank_left < rank_int) {
7761                 kind_left = ATOMIC_TYPE_INT;
7762                 rank_left = rank_int;
7763         }
7764         if (rank_right < rank_int) {
7765                 kind_right = ATOMIC_TYPE_INT;
7766                 rank_right = rank_int;
7767         }
7768         if (kind_left == kind_right)
7769                 return kind_left;
7770
7771         bool const signed_left  = is_akind_signed(kind_left);
7772         bool const signed_right = is_akind_signed(kind_right);
7773         if (signed_left == signed_right)
7774                 return rank_left >= rank_right ? kind_left : kind_right;
7775
7776         unsigned           s_rank;
7777         unsigned           u_rank;
7778         atomic_type_kind_t s_kind;
7779         atomic_type_kind_t u_kind;
7780         if (signed_left) {
7781                 s_kind = kind_left;
7782                 s_rank = rank_left;
7783                 u_kind = kind_right;
7784                 u_rank = rank_right;
7785         } else {
7786                 s_kind = kind_right;
7787                 s_rank = rank_right;
7788                 u_kind = kind_left;
7789                 u_rank = rank_left;
7790         }
7791         if (u_rank >= s_rank)
7792                 return u_kind;
7793         if (get_atomic_type_size(s_kind) > get_atomic_type_size(u_kind))
7794                 return s_kind;
7795
7796         switch (s_kind) {
7797         case ATOMIC_TYPE_INT:      return ATOMIC_TYPE_UINT;
7798         case ATOMIC_TYPE_LONG:     return ATOMIC_TYPE_ULONG;
7799         case ATOMIC_TYPE_LONGLONG: return ATOMIC_TYPE_ULONGLONG;
7800         default: panic("invalid atomic type");
7801         }
7802 }
7803
7804 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7805 {
7806         atomic_type_kind_t kind_left  = get_arithmetic_akind(type_left);
7807         atomic_type_kind_t kind_right = get_arithmetic_akind(type_right);
7808         atomic_type_kind_t kind_res   = semantic_arithmetic_(kind_left, kind_right);
7809
7810         if (type_left->kind == TYPE_COMPLEX || type_right->kind == TYPE_COMPLEX) {
7811                 return make_complex_type(kind_res, TYPE_QUALIFIER_NONE);
7812         }
7813         return make_atomic_type(kind_res, TYPE_QUALIFIER_NONE);
7814 }
7815
7816 /**
7817  * Check the semantic restrictions for a binary expression.
7818  */
7819 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7820 {
7821         expression_t *const left            = expression->left;
7822         expression_t *const right           = expression->right;
7823         type_t       *const orig_type_left  = left->base.type;
7824         type_t       *const orig_type_right = right->base.type;
7825         type_t       *const type_left       = skip_typeref(orig_type_left);
7826         type_t       *const type_right      = skip_typeref(orig_type_right);
7827
7828         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7829                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7830                         position_t const *const pos = &expression->base.pos;
7831                         errorf(pos, "operands of binary expression must have arithmetic types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7832                 }
7833                 return;
7834         }
7835
7836         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7837         expression->left      = create_implicit_cast(left, arithmetic_type);
7838         expression->right     = create_implicit_cast(right, arithmetic_type);
7839         expression->base.type = arithmetic_type;
7840 }
7841
7842 static void semantic_binexpr_integer(binary_expression_t *const expression)
7843 {
7844         expression_t *const left            = expression->left;
7845         expression_t *const right           = expression->right;
7846         type_t       *const orig_type_left  = left->base.type;
7847         type_t       *const orig_type_right = right->base.type;
7848         type_t       *const type_left       = skip_typeref(orig_type_left);
7849         type_t       *const type_right      = skip_typeref(orig_type_right);
7850
7851         if (!is_type_integer(type_left) || !is_type_integer(type_right)
7852           || is_type_complex(type_left) || is_type_complex(type_right)) {
7853                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7854                         position_t const *const pos = &expression->base.pos;
7855                         errorf(pos, "operands of binary expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7856                 }
7857                 return;
7858         }
7859
7860         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7861         expression->left      = create_implicit_cast(left, result_type);
7862         expression->right     = create_implicit_cast(right, result_type);
7863         expression->base.type = result_type;
7864 }
7865
7866 static void warn_div_by_zero(binary_expression_t const *const expression)
7867 {
7868         if (!is_type_integer(expression->base.type))
7869                 return;
7870
7871         expression_t const *const right = expression->right;
7872         /* The type of the right operand can be different for /= */
7873         if (is_type_integer(skip_typeref(right->base.type))      &&
7874             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7875             !fold_constant_to_bool(right)) {
7876                 position_t const *const pos = &expression->base.pos;
7877                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7878         }
7879 }
7880
7881 /**
7882  * Check the semantic restrictions for a div expression.
7883  */
7884 static void semantic_div(binary_expression_t *expression)
7885 {
7886         semantic_binexpr_arithmetic(expression);
7887         warn_div_by_zero(expression);
7888 }
7889
7890 /**
7891  * Check the semantic restrictions for a mod expression.
7892  */
7893 static void semantic_mod(binary_expression_t *expression)
7894 {
7895         semantic_binexpr_integer(expression);
7896         warn_div_by_zero(expression);
7897 }
7898
7899 static void warn_addsub_in_shift(const expression_t *const expr)
7900 {
7901         if (expr->base.parenthesized)
7902                 return;
7903
7904         char op;
7905         switch (expr->kind) {
7906                 case EXPR_BINARY_ADD: op = '+'; break;
7907                 case EXPR_BINARY_SUB: op = '-'; break;
7908                 default:              return;
7909         }
7910
7911         position_t const *const pos = &expr->base.pos;
7912         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7913 }
7914
7915 static bool semantic_shift(binary_expression_t *expression)
7916 {
7917         expression_t *const left            = expression->left;
7918         expression_t *const right           = expression->right;
7919         type_t       *const orig_type_left  = left->base.type;
7920         type_t       *const orig_type_right = right->base.type;
7921         type_t       *      type_left       = skip_typeref(orig_type_left);
7922         type_t       *      type_right      = skip_typeref(orig_type_right);
7923
7924         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7925                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7926                         position_t const *const pos = &expression->base.pos;
7927                         errorf(pos, "operands of shift expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7928                 }
7929                 return false;
7930         }
7931
7932         type_left = promote_integer(type_left);
7933
7934         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7935                 position_t const *const pos   = &right->base.pos;
7936                 long              const count = fold_constant_to_int(right);
7937                 if (count < 0) {
7938                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7939                 } else if ((unsigned long)count >=
7940                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7941                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7942                 }
7943         }
7944
7945         type_right        = promote_integer(type_right);
7946         expression->right = create_implicit_cast(right, type_right);
7947
7948         return true;
7949 }
7950
7951 static void semantic_shift_op(binary_expression_t *expression)
7952 {
7953         expression_t *const left  = expression->left;
7954         expression_t *const right = expression->right;
7955
7956         if (!semantic_shift(expression))
7957                 return;
7958
7959         warn_addsub_in_shift(left);
7960         warn_addsub_in_shift(right);
7961
7962         type_t *const orig_type_left = left->base.type;
7963         type_t *      type_left      = skip_typeref(orig_type_left);
7964
7965         type_left             = promote_integer(type_left);
7966         expression->left      = create_implicit_cast(left, type_left);
7967         expression->base.type = type_left;
7968 }
7969
7970 static void semantic_add(binary_expression_t *expression)
7971 {
7972         expression_t *const left            = expression->left;
7973         expression_t *const right           = expression->right;
7974         type_t       *const orig_type_left  = left->base.type;
7975         type_t       *const orig_type_right = right->base.type;
7976         type_t       *const type_left       = skip_typeref(orig_type_left);
7977         type_t       *const type_right      = skip_typeref(orig_type_right);
7978
7979         /* §6.5.6 */
7980         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7981                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7982                 expression->left  = create_implicit_cast(left, arithmetic_type);
7983                 expression->right = create_implicit_cast(right, arithmetic_type);
7984                 expression->base.type = arithmetic_type;
7985         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7986                 check_pointer_arithmetic(&expression->base.pos, type_left,
7987                                          orig_type_left);
7988                 expression->base.type = type_left;
7989         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7990                 check_pointer_arithmetic(&expression->base.pos, type_right,
7991                                          orig_type_right);
7992                 expression->base.type = type_right;
7993         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7994                 errorf(&expression->base.pos,
7995                        "invalid operands to binary + ('%T', '%T')",
7996                        orig_type_left, orig_type_right);
7997         }
7998 }
7999
8000 static void semantic_sub(binary_expression_t *expression)
8001 {
8002         expression_t     *const left            = expression->left;
8003         expression_t     *const right           = expression->right;
8004         type_t           *const orig_type_left  = left->base.type;
8005         type_t           *const orig_type_right = right->base.type;
8006         type_t           *const type_left       = skip_typeref(orig_type_left);
8007         type_t           *const type_right      = skip_typeref(orig_type_right);
8008         position_t const *const pos             = &expression->base.pos;
8009
8010         /* §5.6.5 */
8011         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8012                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8013                 expression->left        = create_implicit_cast(left, arithmetic_type);
8014                 expression->right       = create_implicit_cast(right, arithmetic_type);
8015                 expression->base.type =  arithmetic_type;
8016         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8017                 check_pointer_arithmetic(&expression->base.pos, type_left,
8018                                          orig_type_left);
8019                 expression->base.type = type_left;
8020         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8021                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8022                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8023                 if (!types_compatible(unqual_left, unqual_right)) {
8024                         errorf(pos,
8025                                "subtracting pointers to incompatible types '%T' and '%T'",
8026                                orig_type_left, orig_type_right);
8027                 } else if (!is_type_object(unqual_left)) {
8028                         if (!is_type_void(unqual_left)) {
8029                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8030                                        orig_type_left);
8031                         } else {
8032                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8033                         }
8034                 }
8035                 expression->base.type = type_ptrdiff_t;
8036         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8037                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8038                        orig_type_left, orig_type_right);
8039         }
8040 }
8041
8042 static void warn_string_literal_address(expression_t const* expr)
8043 {
8044         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8045                 expr = expr->unary.value;
8046                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8047                         return;
8048                 expr = expr->unary.value;
8049         }
8050
8051         if (expr->kind == EXPR_STRING_LITERAL) {
8052                 position_t const *const pos = &expr->base.pos;
8053                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8054         }
8055 }
8056
8057 static bool maybe_negative(expression_t const *const expr)
8058 {
8059         switch (is_constant_expression(expr)) {
8060                 case EXPR_CLASS_ERROR:    return false;
8061                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8062                 default:                  return true;
8063         }
8064 }
8065
8066 static void warn_comparison(position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8067 {
8068         warn_string_literal_address(expr);
8069
8070         expression_t const* const ref = get_reference_address(expr);
8071         if (ref != NULL && is_null_pointer_constant(other)) {
8072                 entity_t const *const ent = ref->reference.entity;
8073                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8074         }
8075
8076         if (!expr->base.parenthesized) {
8077                 switch (expr->base.kind) {
8078                         case EXPR_BINARY_LESS:
8079                         case EXPR_BINARY_GREATER:
8080                         case EXPR_BINARY_LESSEQUAL:
8081                         case EXPR_BINARY_GREATEREQUAL:
8082                         case EXPR_BINARY_NOTEQUAL:
8083                         case EXPR_BINARY_EQUAL:
8084                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8085                                 break;
8086                         default:
8087                                 break;
8088                 }
8089         }
8090 }
8091
8092 /**
8093  * Check the semantics of comparison expressions.
8094  */
8095 static void semantic_comparison(binary_expression_t *expression,
8096                                 bool is_relational)
8097 {
8098         position_t const *const pos   = &expression->base.pos;
8099         expression_t     *const left  = expression->left;
8100         expression_t     *const right = expression->right;
8101
8102         warn_comparison(pos, left, right);
8103         warn_comparison(pos, right, left);
8104
8105         type_t *orig_type_left  = left->base.type;
8106         type_t *orig_type_right = right->base.type;
8107         type_t *type_left       = skip_typeref(orig_type_left);
8108         type_t *type_right      = skip_typeref(orig_type_right);
8109
8110         /* TODO non-arithmetic types */
8111         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8112                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8113
8114                 /* test for signed vs unsigned compares */
8115                 if (is_type_integer(arithmetic_type)) {
8116                         bool const signed_left  = is_type_signed(type_left);
8117                         bool const signed_right = is_type_signed(type_right);
8118                         if (signed_left != signed_right) {
8119                                 /* FIXME long long needs better const folding magic */
8120                                 /* TODO check whether constant value can be represented by other type */
8121                                 if ((signed_left  && maybe_negative(left)) ||
8122                                                 (signed_right && maybe_negative(right))) {
8123                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8124                                 }
8125                         }
8126                 }
8127
8128                 expression->left      = create_implicit_cast(left, arithmetic_type);
8129                 expression->right     = create_implicit_cast(right, arithmetic_type);
8130                 expression->base.type = arithmetic_type;
8131                 if (!is_relational && is_type_float(arithmetic_type)) {
8132                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8133                 }
8134                 /* for relational ops we need real types, not just arithmetic */
8135                 if (is_relational
8136                     && (!is_type_real(type_left) || !is_type_real(type_right))) {
8137                         type_error_incompatible("invalid operands for relational operator", pos, type_left, type_right);
8138                 }
8139         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8140                 /* TODO check compatibility */
8141         } else if (is_type_pointer(type_left)) {
8142                 expression->right = create_implicit_cast(right, type_left);
8143         } else if (is_type_pointer(type_right)) {
8144                 expression->left = create_implicit_cast(left, type_right);
8145         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8146                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8147         }
8148         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8149 }
8150
8151 static void semantic_relational(binary_expression_t *expression)
8152 {
8153         semantic_comparison(expression, true);
8154 }
8155
8156 static void semantic_equality(binary_expression_t *expression)
8157 {
8158         semantic_comparison(expression, false);
8159 }
8160
8161 /**
8162  * Checks if a compound type has constant fields.
8163  */
8164 static bool has_const_fields(const compound_type_t *type)
8165 {
8166         compound_t *compound = type->compound;
8167         entity_t   *entry    = compound->members.entities;
8168
8169         for (; entry != NULL; entry = entry->base.next) {
8170                 if (!is_declaration(entry))
8171                         continue;
8172
8173                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8174                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8175                         return true;
8176         }
8177
8178         return false;
8179 }
8180
8181 static bool is_valid_assignment_lhs(expression_t const* const left)
8182 {
8183         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8184         type_t *const type_left      = skip_typeref(orig_type_left);
8185
8186         if (!is_lvalue(left)) {
8187                 errorf(&left->base.pos,
8188                        "left hand side '%E' of assignment is not an lvalue", left);
8189                 return false;
8190         }
8191
8192         if (left->kind == EXPR_REFERENCE
8193                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8194                 errorf(&left->base.pos, "cannot assign to function '%E'", left);
8195                 return false;
8196         }
8197
8198         if (is_type_array(type_left)) {
8199                 errorf(&left->base.pos, "cannot assign to array '%E'", left);
8200                 return false;
8201         }
8202         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8203                 errorf(&left->base.pos,
8204                        "assignment to read-only location '%E' (type '%T')", left,
8205                        orig_type_left);
8206                 return false;
8207         }
8208         if (is_type_incomplete(type_left)) {
8209                 errorf(&left->base.pos, "left-hand side '%E' of assignment has incomplete type '%T'",
8210                        left, orig_type_left);
8211                 return false;
8212         }
8213         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8214                 errorf(&left->base.pos, "cannot assign to '%E' because compound type '%T' has read-only fields",
8215                        left, orig_type_left);
8216                 return false;
8217         }
8218
8219         return true;
8220 }
8221
8222 static void semantic_arithmetic_assign(binary_expression_t *expression)
8223 {
8224         expression_t *left            = expression->left;
8225         expression_t *right           = expression->right;
8226         type_t       *orig_type_left  = left->base.type;
8227         type_t       *orig_type_right = right->base.type;
8228
8229         if (!is_valid_assignment_lhs(left))
8230                 return;
8231
8232         type_t *type_left  = skip_typeref(orig_type_left);
8233         type_t *type_right = skip_typeref(orig_type_right);
8234
8235         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8236                 /* TODO: improve error message */
8237                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8238                         errorf(&expression->base.pos, "operation needs arithmetic types");
8239                 }
8240                 return;
8241         }
8242
8243         /* combined instructions are tricky. We can't create an implicit cast on
8244          * the left side, because we need the uncasted form for the store.
8245          * The ast2firm pass has to know that left_type must be right_type
8246          * for the arithmetic operation and create a cast by itself */
8247         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8248         expression->right       = create_implicit_cast(right, arithmetic_type);
8249         expression->base.type   = type_left;
8250 }
8251
8252 static void semantic_divmod_assign(binary_expression_t *expression)
8253 {
8254         semantic_arithmetic_assign(expression);
8255         warn_div_by_zero(expression);
8256 }
8257
8258 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8259 {
8260         expression_t *const left            = expression->left;
8261         expression_t *const right           = expression->right;
8262         type_t       *const orig_type_left  = left->base.type;
8263         type_t       *const orig_type_right = right->base.type;
8264         type_t       *const type_left       = skip_typeref(orig_type_left);
8265         type_t       *const type_right      = skip_typeref(orig_type_right);
8266
8267         if (!is_valid_assignment_lhs(left))
8268                 return;
8269
8270         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8271                 /* combined instructions are tricky. We can't create an implicit cast on
8272                  * the left side, because we need the uncasted form for the store.
8273                  * The ast2firm pass has to know that left_type must be right_type
8274                  * for the arithmetic operation and create a cast by itself */
8275                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8276                 expression->right     = create_implicit_cast(right, arithmetic_type);
8277                 expression->base.type = type_left;
8278         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8279                 check_pointer_arithmetic(&expression->base.pos, type_left,
8280                                          orig_type_left);
8281                 expression->base.type = type_left;
8282         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8283                 errorf(&expression->base.pos,
8284                        "incompatible types '%T' and '%T' in assignment",
8285                        orig_type_left, orig_type_right);
8286         }
8287 }
8288
8289 static void semantic_integer_assign(binary_expression_t *expression)
8290 {
8291         expression_t *left            = expression->left;
8292         expression_t *right           = expression->right;
8293         type_t       *orig_type_left  = left->base.type;
8294         type_t       *orig_type_right = right->base.type;
8295
8296         if (!is_valid_assignment_lhs(left))
8297                 return;
8298
8299         type_t *type_left  = skip_typeref(orig_type_left);
8300         type_t *type_right = skip_typeref(orig_type_right);
8301
8302         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8303                 /* TODO: improve error message */
8304                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8305                         errorf(&expression->base.pos, "operation needs integer types");
8306                 }
8307                 return;
8308         }
8309
8310         /* combined instructions are tricky. We can't create an implicit cast on
8311          * the left side, because we need the uncasted form for the store.
8312          * The ast2firm pass has to know that left_type must be right_type
8313          * for the arithmetic operation and create a cast by itself */
8314         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8315         expression->right       = create_implicit_cast(right, arithmetic_type);
8316         expression->base.type   = type_left;
8317 }
8318
8319 static void semantic_shift_assign(binary_expression_t *expression)
8320 {
8321         expression_t *left           = expression->left;
8322
8323         if (!is_valid_assignment_lhs(left))
8324                 return;
8325
8326         if (!semantic_shift(expression))
8327                 return;
8328
8329         expression->base.type = skip_typeref(left->base.type);
8330 }
8331
8332 static void warn_logical_and_within_or(const expression_t *const expr)
8333 {
8334         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8335                 return;
8336         if (expr->base.parenthesized)
8337                 return;
8338         position_t const *const pos = &expr->base.pos;
8339         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8340 }
8341
8342 /**
8343  * Check the semantic restrictions of a logical expression.
8344  */
8345 static void semantic_logical_op(binary_expression_t *expression)
8346 {
8347         /* §6.5.13:2  Each of the operands shall have scalar type.
8348          * §6.5.14:2  Each of the operands shall have scalar type. */
8349         semantic_condition(expression->left,   "left operand of logical operator");
8350         semantic_condition(expression->right, "right operand of logical operator");
8351         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8352                 warn_logical_and_within_or(expression->left);
8353                 warn_logical_and_within_or(expression->right);
8354         }
8355         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8356 }
8357
8358 /**
8359  * Check the semantic restrictions of a binary assign expression.
8360  */
8361 static void semantic_binexpr_assign(binary_expression_t *expression)
8362 {
8363         expression_t *left           = expression->left;
8364         type_t       *orig_type_left = left->base.type;
8365
8366         if (!is_valid_assignment_lhs(left))
8367                 return;
8368
8369         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8370         report_assign_error(error, orig_type_left, expression->right,
8371                             "assignment", &left->base.pos);
8372         expression->right = create_implicit_cast(expression->right, orig_type_left);
8373         expression->base.type = orig_type_left;
8374 }
8375
8376 /**
8377  * Determine if the outermost operation (or parts thereof) of the given
8378  * expression has no effect in order to generate a warning about this fact.
8379  * Therefore in some cases this only examines some of the operands of the
8380  * expression (see comments in the function and examples below).
8381  * Examples:
8382  *   f() + 23;    // warning, because + has no effect
8383  *   x || f();    // no warning, because x controls execution of f()
8384  *   x ? y : f(); // warning, because y has no effect
8385  *   (void)x;     // no warning to be able to suppress the warning
8386  * This function can NOT be used for an "expression has definitely no effect"-
8387  * analysis. */
8388 static bool expression_has_effect(const expression_t *const expr)
8389 {
8390         switch (expr->kind) {
8391                 case EXPR_ERROR:                      return true; /* do NOT warn */
8392                 case EXPR_REFERENCE:                  return false;
8393                 case EXPR_ENUM_CONSTANT:              return false;
8394                 case EXPR_LABEL_ADDRESS:              return false;
8395
8396                 /* suppress the warning for microsoft __noop operations */
8397                 case EXPR_LITERAL_MS_NOOP:            return true;
8398                 case EXPR_LITERAL_BOOLEAN:
8399                 case EXPR_LITERAL_CHARACTER:
8400                 case EXPR_LITERAL_INTEGER:
8401                 case EXPR_LITERAL_FLOATINGPOINT:
8402                 case EXPR_STRING_LITERAL:             return false;
8403
8404                 case EXPR_CALL: {
8405                         const call_expression_t *const call = &expr->call;
8406                         if (call->function->kind != EXPR_REFERENCE)
8407                                 return true;
8408
8409                         switch (call->function->reference.entity->function.btk) {
8410                                 /* FIXME: which builtins have no effect? */
8411                                 default:                      return true;
8412                         }
8413                 }
8414
8415                 /* Generate the warning if either the left or right hand side of a
8416                  * conditional expression has no effect */
8417                 case EXPR_CONDITIONAL: {
8418                         conditional_expression_t const *const cond = &expr->conditional;
8419                         expression_t             const *const t    = cond->true_expression;
8420                         return
8421                                 (t == NULL || expression_has_effect(t)) &&
8422                                 expression_has_effect(cond->false_expression);
8423                 }
8424
8425                 case EXPR_SELECT:                     return false;
8426                 case EXPR_ARRAY_ACCESS:               return false;
8427                 case EXPR_SIZEOF:                     return false;
8428                 case EXPR_CLASSIFY_TYPE:              return false;
8429                 case EXPR_ALIGNOF:                    return false;
8430
8431                 case EXPR_FUNCNAME:                   return false;
8432                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8433                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8434                 case EXPR_OFFSETOF:                   return false;
8435                 case EXPR_VA_START:                   return true;
8436                 case EXPR_VA_ARG:                     return true;
8437                 case EXPR_VA_COPY:                    return true;
8438                 case EXPR_STATEMENT:                  return true; // TODO
8439                 case EXPR_COMPOUND_LITERAL:           return false;
8440
8441                 case EXPR_UNARY_NEGATE:               return false;
8442                 case EXPR_UNARY_PLUS:                 return false;
8443                 case EXPR_UNARY_COMPLEMENT:           return false;
8444                 case EXPR_UNARY_NOT:                  return false;
8445                 case EXPR_UNARY_DEREFERENCE:          return false;
8446                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8447                 case EXPR_UNARY_REAL:                 return false;
8448                 case EXPR_UNARY_IMAG:                 return false;
8449                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8450                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8451                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8452                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8453
8454                 /* Treat void casts as if they have an effect in order to being able to
8455                  * suppress the warning */
8456                 case EXPR_UNARY_CAST: {
8457                         type_t *const type = skip_typeref(expr->base.type);
8458                         return is_type_void(type);
8459                 }
8460
8461                 case EXPR_UNARY_ASSUME:               return true;
8462                 case EXPR_UNARY_DELETE:               return true;
8463                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8464                 case EXPR_UNARY_THROW:                return true;
8465
8466                 case EXPR_BINARY_ADD:                 return false;
8467                 case EXPR_BINARY_SUB:                 return false;
8468                 case EXPR_BINARY_MUL:                 return false;
8469                 case EXPR_BINARY_DIV:                 return false;
8470                 case EXPR_BINARY_MOD:                 return false;
8471                 case EXPR_BINARY_EQUAL:               return false;
8472                 case EXPR_BINARY_NOTEQUAL:            return false;
8473                 case EXPR_BINARY_LESS:                return false;
8474                 case EXPR_BINARY_LESSEQUAL:           return false;
8475                 case EXPR_BINARY_GREATER:             return false;
8476                 case EXPR_BINARY_GREATEREQUAL:        return false;
8477                 case EXPR_BINARY_BITWISE_AND:         return false;
8478                 case EXPR_BINARY_BITWISE_OR:          return false;
8479                 case EXPR_BINARY_BITWISE_XOR:         return false;
8480                 case EXPR_BINARY_SHIFTLEFT:           return false;
8481                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8482                 case EXPR_BINARY_ASSIGN:              return true;
8483                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8484                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8485                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8486                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8487                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8488                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8489                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8490                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8491                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8492                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8493
8494                 /* Only examine the right hand side of && and ||, because the left hand
8495                  * side already has the effect of controlling the execution of the right
8496                  * hand side */
8497                 case EXPR_BINARY_LOGICAL_AND:
8498                 case EXPR_BINARY_LOGICAL_OR:
8499                 /* Only examine the right hand side of a comma expression, because the left
8500                  * hand side has a separate warning */
8501                 case EXPR_BINARY_COMMA:
8502                         return expression_has_effect(expr->binary.right);
8503
8504                 case EXPR_BINARY_ISGREATER:           return false;
8505                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8506                 case EXPR_BINARY_ISLESS:              return false;
8507                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8508                 case EXPR_BINARY_ISLESSGREATER:       return false;
8509                 case EXPR_BINARY_ISUNORDERED:         return false;
8510         }
8511
8512         internal_errorf(HERE, "unexpected expression");
8513 }
8514
8515 static void semantic_comma(binary_expression_t *expression)
8516 {
8517         const expression_t *const left = expression->left;
8518         if (!expression_has_effect(left)) {
8519                 position_t const *const pos = &left->base.pos;
8520                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8521         }
8522         expression->base.type = expression->right->base.type;
8523 }
8524
8525 /**
8526  * @param prec_r precedence of the right operand
8527  */
8528 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8529 static expression_t *parse_##binexpression_type(expression_t *left)          \
8530 {                                                                            \
8531         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8532         binexpr->binary.left  = left;                                            \
8533         eat(token_kind);                                                         \
8534                                                                              \
8535         expression_t *right = parse_subexpression(prec_r);                       \
8536                                                                              \
8537         binexpr->binary.right = right;                                           \
8538         sfunc(&binexpr->binary);                                                 \
8539                                                                              \
8540         return binexpr;                                                          \
8541 }
8542
8543 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8544 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_div)
8545 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_mod)
8546 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8547 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8548 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8549 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8550 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_relational)
8551 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_relational)
8552 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_relational)
8553 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_relational)
8554 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_equality)
8555 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_equality)
8556 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8557 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8558 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8559 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8560 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8561 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8562 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8563 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8564 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8565 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8566 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8567 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8568 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8569 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8570 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8571 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8572 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8573
8574
8575 static expression_t *parse_subexpression(precedence_t precedence)
8576 {
8577         expression_parser_function_t *parser
8578                 = &expression_parsers[token.kind];
8579         expression_t                 *left;
8580
8581         if (parser->parser != NULL) {
8582                 left = parser->parser();
8583         } else {
8584                 left = parse_primary_expression();
8585         }
8586         assert(left != NULL);
8587
8588         while (true) {
8589                 parser = &expression_parsers[token.kind];
8590                 if (parser->infix_parser == NULL)
8591                         break;
8592                 if (parser->infix_precedence < precedence)
8593                         break;
8594
8595                 left = parser->infix_parser(left);
8596
8597                 assert(left != NULL);
8598         }
8599
8600         return left;
8601 }
8602
8603 /**
8604  * Parse an expression.
8605  */
8606 static expression_t *parse_expression(void)
8607 {
8608         return parse_subexpression(PREC_EXPRESSION);
8609 }
8610
8611 /**
8612  * Register a parser for a prefix-like operator.
8613  *
8614  * @param parser      the parser function
8615  * @param token_kind  the token type of the prefix token
8616  */
8617 static void register_expression_parser(parse_expression_function parser,
8618                                        int token_kind)
8619 {
8620         expression_parser_function_t *entry = &expression_parsers[token_kind];
8621
8622         assert(!entry->parser);
8623         entry->parser = parser;
8624 }
8625
8626 /**
8627  * Register a parser for an infix operator with given precedence.
8628  *
8629  * @param parser      the parser function
8630  * @param token_kind  the token type of the infix operator
8631  * @param precedence  the precedence of the operator
8632  */
8633 static void register_infix_parser(parse_expression_infix_function parser,
8634                                   int token_kind, precedence_t precedence)
8635 {
8636         expression_parser_function_t *entry = &expression_parsers[token_kind];
8637
8638         assert(!entry->infix_parser);
8639         entry->infix_parser     = parser;
8640         entry->infix_precedence = precedence;
8641 }
8642
8643 /**
8644  * Initialize the expression parsers.
8645  */
8646 static void init_expression_parsers(void)
8647 {
8648         memset(&expression_parsers, 0, sizeof(expression_parsers));
8649
8650         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8651         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8652         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8653         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8654         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8655         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8656         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8657         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8658         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8659         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8660         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8661         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8662         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8663         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8664         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8665         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8666         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8667         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8668         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8669         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8670         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8671         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8672         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8673         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8674         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8675         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8676         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8677         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8678         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8679         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8680         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8681         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8682         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8683         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8684         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8685         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8686         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8687
8688         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8689         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8690         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8691         register_expression_parser(parse_EXPR_UNARY_COMPLEMENT,       '~');
8692         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8693         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8694         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8695         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8696         register_expression_parser(parse_sizeof,                      T_sizeof);
8697         register_expression_parser(parse_alignof,                     T__Alignof);
8698         register_expression_parser(parse_extension,                   T___extension__);
8699         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8700         register_expression_parser(parse_delete,                      T_delete);
8701         register_expression_parser(parse_throw,                       T_throw);
8702 }
8703
8704 /**
8705  * Parse a asm statement arguments specification.
8706  */
8707 static void parse_asm_arguments(asm_argument_t **anchor, bool const is_out)
8708 {
8709         if (token.kind == T_STRING_LITERAL || token.kind == '[') {
8710                 add_anchor_token(',');
8711                 do {
8712                         asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8713
8714                         add_anchor_token(')');
8715                         add_anchor_token('(');
8716                         add_anchor_token(T_STRING_LITERAL);
8717
8718                         if (accept('[')) {
8719                                 add_anchor_token(']');
8720                                 argument->symbol = expect_identifier("while parsing asm argument", NULL);
8721                                 rem_anchor_token(']');
8722                                 expect(']');
8723                         }
8724
8725                         rem_anchor_token(T_STRING_LITERAL);
8726                         argument->constraints = parse_string_literals("asm argument");
8727                         rem_anchor_token('(');
8728                         expect('(');
8729                         expression_t *expression = parse_expression();
8730                         if (is_out) {
8731                                 /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8732                                  * change size or type representation (e.g. int -> long is ok, but
8733                                  * int -> float is not) */
8734                                 if (expression->kind == EXPR_UNARY_CAST) {
8735                                         type_t      *const type = expression->base.type;
8736                                         type_kind_t  const kind = type->kind;
8737                                         if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8738                                                 unsigned flags;
8739                                                 unsigned size;
8740                                                 if (kind == TYPE_ATOMIC) {
8741                                                         atomic_type_kind_t const akind = type->atomic.akind;
8742                                                         flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8743                                                         size  = get_atomic_type_size(akind);
8744                                                 } else {
8745                                                         flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8746                                                         size  = get_type_size(type_void_ptr);
8747                                                 }
8748
8749                                                 do {
8750                                                         expression_t *const value      = expression->unary.value;
8751                                                         type_t       *const value_type = value->base.type;
8752                                                         type_kind_t   const value_kind = value_type->kind;
8753
8754                                                         unsigned value_flags;
8755                                                         unsigned value_size;
8756                                                         if (value_kind == TYPE_ATOMIC) {
8757                                                                 atomic_type_kind_t const value_akind = value_type->atomic.akind;
8758                                                                 value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8759                                                                 value_size  = get_atomic_type_size(value_akind);
8760                                                         } else if (value_kind == TYPE_POINTER) {
8761                                                                 value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8762                                                                 value_size  = get_type_size(type_void_ptr);
8763                                                         } else {
8764                                                                 break;
8765                                                         }
8766
8767                                                         if (value_flags != flags || value_size != size)
8768                                                                 break;
8769
8770                                                         expression = value;
8771                                                 } while (expression->kind == EXPR_UNARY_CAST);
8772                                         }
8773                                 }
8774
8775                                 if (!is_lvalue(expression))
8776                                         errorf(&expression->base.pos,
8777                                                "asm output argument is not an lvalue");
8778
8779                                 if (argument->constraints.begin[0] == '=')
8780                                         determine_lhs_ent(expression, NULL);
8781                                 else
8782                                         mark_vars_read(expression, NULL);
8783                         } else {
8784                                 mark_vars_read(expression, NULL);
8785                         }
8786                         argument->expression = expression;
8787                         rem_anchor_token(')');
8788                         expect(')');
8789
8790                         set_address_taken(expression, true);
8791
8792                         *anchor = argument;
8793                         anchor  = &argument->next;
8794                 } while (accept(','));
8795                 rem_anchor_token(',');
8796         }
8797 }
8798
8799 /**
8800  * Parse a asm statement clobber specification.
8801  */
8802 static void parse_asm_clobbers(asm_clobber_t **anchor)
8803 {
8804         if (token.kind == T_STRING_LITERAL) {
8805                 add_anchor_token(',');
8806                 do {
8807                         asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8808                         clobber->clobber       = parse_string_literals(NULL);
8809
8810                         *anchor = clobber;
8811                         anchor  = &clobber->next;
8812                 } while (accept(','));
8813                 rem_anchor_token(',');
8814         }
8815 }
8816
8817 static void parse_asm_labels(asm_label_t **anchor)
8818 {
8819         if (token.kind == T_IDENTIFIER) {
8820                 add_anchor_token(',');
8821                 do {
8822                         label_t *const label = get_label("while parsing 'asm goto' labels");
8823                         if (label) {
8824                                 asm_label_t *const asm_label = allocate_ast_zero(sizeof(*asm_label));
8825                                 asm_label->label = label;
8826
8827                                 *anchor = asm_label;
8828                                 anchor  = &asm_label->next;
8829                         }
8830                 } while (accept(','));
8831                 rem_anchor_token(',');
8832         }
8833 }
8834
8835 /**
8836  * Parse an asm statement.
8837  */
8838 static statement_t *parse_asm_statement(void)
8839 {
8840         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8841         asm_statement_t *asm_statement = &statement->asms;
8842
8843         eat(T_asm);
8844         add_anchor_token(')');
8845         add_anchor_token(':');
8846         add_anchor_token(T_STRING_LITERAL);
8847
8848         if (accept(T_volatile))
8849                 asm_statement->is_volatile = true;
8850
8851         bool const asm_goto = accept(T_goto);
8852
8853         expect('(');
8854         rem_anchor_token(T_STRING_LITERAL);
8855         asm_statement->asm_text = parse_string_literals("asm statement");
8856
8857         if (accept(':')) parse_asm_arguments(&asm_statement->outputs, true);
8858         if (accept(':')) parse_asm_arguments(&asm_statement->inputs, false);
8859         if (accept(':')) parse_asm_clobbers( &asm_statement->clobbers);
8860
8861         rem_anchor_token(':');
8862         if (accept(':')) {
8863                 if (!asm_goto)
8864                         warningf(WARN_OTHER, &statement->base.pos, "assembler statement with labels should be 'asm goto'");
8865                 parse_asm_labels(&asm_statement->labels);
8866                 if (asm_statement->labels)
8867                         errorf(&statement->base.pos, "'asm goto' not supported");
8868         } else {
8869                 if (asm_goto)
8870                         warningf(WARN_OTHER, &statement->base.pos, "'asm goto' without labels");
8871         }
8872
8873         rem_anchor_token(')');
8874         expect(')');
8875         expect(';');
8876
8877         if (asm_statement->outputs == NULL) {
8878                 /* GCC: An 'asm' instruction without any output operands will be treated
8879                  * identically to a volatile 'asm' instruction. */
8880                 asm_statement->is_volatile = true;
8881         }
8882
8883         return statement;
8884 }
8885
8886 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8887 {
8888         statement_t *inner_stmt;
8889         switch (token.kind) {
8890                 case '}':
8891                         errorf(&label->base.pos, "%s at end of compound statement", label_kind);
8892                         inner_stmt = create_error_statement();
8893                         break;
8894
8895                 case ';':
8896                         if (label->kind == STATEMENT_LABEL) {
8897                                 /* Eat an empty statement here, to avoid the warning about an empty
8898                                  * statement after a label.  label:; is commonly used to have a label
8899                                  * before a closing brace. */
8900                                 inner_stmt = create_empty_statement();
8901                                 eat(';');
8902                                 break;
8903                         }
8904                         /* FALLTHROUGH */
8905
8906                 default:
8907                         inner_stmt = parse_statement();
8908                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8909                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8910                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8911                                 errorf(&inner_stmt->base.pos, "declaration after %s", label_kind);
8912                         }
8913                         break;
8914         }
8915         return inner_stmt;
8916 }
8917
8918 /**
8919  * Parse a case statement.
8920  */
8921 static statement_t *parse_case_statement(void)
8922 {
8923         statement_t *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8924         position_t  *const pos       = &statement->base.pos;
8925
8926         eat(T_case);
8927         add_anchor_token(':');
8928
8929         expression_t *expression = parse_expression();
8930         type_t *expression_type = expression->base.type;
8931         type_t *skipped         = skip_typeref(expression_type);
8932         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8933                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8934                        expression, expression_type);
8935         }
8936
8937         type_t *type = expression_type;
8938         if (current_switch != NULL) {
8939                 type_t *switch_type = current_switch->expression->base.type;
8940                 if (is_type_valid(skip_typeref(switch_type))) {
8941                         expression = create_implicit_cast(expression, switch_type);
8942                 }
8943         }
8944
8945         statement->case_label.expression = expression;
8946         expression_classification_t const expr_class = is_constant_expression(expression);
8947         if (expr_class != EXPR_CLASS_CONSTANT) {
8948                 if (expr_class != EXPR_CLASS_ERROR) {
8949                         errorf(pos, "case label does not reduce to an integer constant");
8950                 }
8951                 statement->case_label.is_bad = true;
8952         } else {
8953                 ir_tarval *val = fold_constant_to_tarval(expression);
8954                 statement->case_label.first_case = val;
8955                 statement->case_label.last_case  = val;
8956         }
8957
8958         if (GNU_MODE) {
8959                 if (accept(T_DOTDOTDOT)) {
8960                         expression_t *end_range = parse_expression();
8961                         expression_type = expression->base.type;
8962                         skipped         = skip_typeref(expression_type);
8963                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8964                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8965                                            expression, expression_type);
8966                         }
8967
8968                         end_range = create_implicit_cast(end_range, type);
8969                         statement->case_label.end_range = end_range;
8970                         expression_classification_t const end_class = is_constant_expression(end_range);
8971                         if (end_class != EXPR_CLASS_CONSTANT) {
8972                                 if (end_class != EXPR_CLASS_ERROR) {
8973                                         errorf(pos, "case range does not reduce to an integer constant");
8974                                 }
8975                                 statement->case_label.is_bad = true;
8976                         } else {
8977                                 ir_tarval *val = fold_constant_to_tarval(end_range);
8978                                 statement->case_label.last_case = val;
8979
8980                                 if (tarval_cmp(val, statement->case_label.first_case)
8981                                     == ir_relation_less) {
8982                                         statement->case_label.is_empty_range = true;
8983                                         warningf(WARN_OTHER, pos, "empty range specified");
8984                                 }
8985                         }
8986                 }
8987         }
8988
8989         PUSH_PARENT(statement);
8990
8991         rem_anchor_token(':');
8992         expect(':');
8993
8994         if (current_switch != NULL) {
8995                 if (! statement->case_label.is_bad) {
8996                         /* Check for duplicate case values */
8997                         case_label_statement_t *c = &statement->case_label;
8998                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8999                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9000                                         continue;
9001
9002                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9003                                         continue;
9004
9005                                 errorf(pos, "duplicate case value (previously used %P)",
9006                                        &l->base.pos);
9007                                 break;
9008                         }
9009                 }
9010                 /* link all cases into the switch statement */
9011                 if (current_switch->last_case == NULL) {
9012                         current_switch->first_case      = &statement->case_label;
9013                 } else {
9014                         current_switch->last_case->next = &statement->case_label;
9015                 }
9016                 current_switch->last_case = &statement->case_label;
9017         } else {
9018                 errorf(pos, "case label not within a switch statement");
9019         }
9020
9021         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9022
9023         POP_PARENT();
9024         return statement;
9025 }
9026
9027 /**
9028  * Parse a default statement.
9029  */
9030 static statement_t *parse_default_statement(void)
9031 {
9032         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9033
9034         eat(T_default);
9035
9036         PUSH_PARENT(statement);
9037
9038         expect(':');
9039
9040         if (current_switch != NULL) {
9041                 const case_label_statement_t *def_label = current_switch->default_label;
9042                 if (def_label != NULL) {
9043                         errorf(&statement->base.pos, "multiple default labels in one switch (previous declared %P)", &def_label->base.pos);
9044                 } else {
9045                         current_switch->default_label = &statement->case_label;
9046
9047                         /* link all cases into the switch statement */
9048                         if (current_switch->last_case == NULL) {
9049                                 current_switch->first_case      = &statement->case_label;
9050                         } else {
9051                                 current_switch->last_case->next = &statement->case_label;
9052                         }
9053                         current_switch->last_case = &statement->case_label;
9054                 }
9055         } else {
9056                 errorf(&statement->base.pos,
9057                        "'default' label not within a switch statement");
9058         }
9059
9060         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9061
9062         POP_PARENT();
9063         return statement;
9064 }
9065
9066 /**
9067  * Parse a label statement.
9068  */
9069 static statement_t *parse_label_statement(void)
9070 {
9071         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9072         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
9073         statement->label.label = label;
9074
9075         PUSH_PARENT(statement);
9076
9077         /* if statement is already set then the label is defined twice,
9078          * otherwise it was just mentioned in a goto/local label declaration so far
9079          */
9080         position_t const* const pos = &statement->base.pos;
9081         if (label->statement != NULL) {
9082                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.pos);
9083         } else {
9084                 label->base.pos  = *pos;
9085                 label->statement = statement;
9086                 label->n_users  += 1;
9087         }
9088
9089         eat(':');
9090
9091         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9092                 parse_attributes(NULL); // TODO process attributes
9093         }
9094
9095         statement->label.statement = parse_label_inner_statement(statement, "label");
9096
9097         /* remember the labels in a list for later checking */
9098         *label_anchor = &statement->label;
9099         label_anchor  = &statement->label.next;
9100
9101         POP_PARENT();
9102         return statement;
9103 }
9104
9105 static statement_t *parse_inner_statement(void)
9106 {
9107         statement_t *const stmt = parse_statement();
9108         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9109         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9110         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9111                 errorf(&stmt->base.pos, "declaration as inner statement, use {}");
9112         }
9113         return stmt;
9114 }
9115
9116 /**
9117  * Parse an expression in parentheses and mark its variables as read.
9118  */
9119 static expression_t *parse_condition(void)
9120 {
9121         add_anchor_token(')');
9122         expect('(');
9123         expression_t *const expr = parse_expression();
9124         mark_vars_read(expr, NULL);
9125         rem_anchor_token(')');
9126         expect(')');
9127         return expr;
9128 }
9129
9130 /**
9131  * Parse an if statement.
9132  */
9133 static statement_t *parse_if(void)
9134 {
9135         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9136
9137         eat(T_if);
9138
9139         PUSH_PARENT(statement);
9140         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9141
9142         add_anchor_token(T_else);
9143
9144         expression_t *const expr = parse_condition();
9145         statement->ifs.condition = expr;
9146         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9147          *             scalar type. */
9148         semantic_condition(expr, "condition of 'if'-statment");
9149
9150         statement_t *const true_stmt = parse_inner_statement();
9151         statement->ifs.true_statement = true_stmt;
9152         rem_anchor_token(T_else);
9153
9154         if (true_stmt->kind == STATEMENT_EMPTY) {
9155                 warningf(WARN_EMPTY_BODY, HERE,
9156                         "suggest braces around empty body in an ‘if’ statement");
9157         }
9158
9159         if (accept(T_else)) {
9160                 statement->ifs.false_statement = parse_inner_statement();
9161
9162                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9163                         warningf(WARN_EMPTY_BODY, HERE,
9164                                         "suggest braces around empty body in an ‘if’ statement");
9165                 }
9166         } else if (true_stmt->kind == STATEMENT_IF &&
9167                         true_stmt->ifs.false_statement != NULL) {
9168                 position_t const *const pos = &true_stmt->base.pos;
9169                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9170         }
9171
9172         POP_SCOPE();
9173         POP_PARENT();
9174         return statement;
9175 }
9176
9177 /**
9178  * Check that all enums are handled in a switch.
9179  *
9180  * @param statement  the switch statement to check
9181  */
9182 static void check_enum_cases(const switch_statement_t *statement)
9183 {
9184         if (!is_warn_on(WARN_SWITCH_ENUM))
9185                 return;
9186         type_t *type = skip_typeref(statement->expression->base.type);
9187         if (! is_type_enum(type))
9188                 return;
9189         enum_type_t *enumt = &type->enumt;
9190
9191         /* if we have a default, no warnings */
9192         if (statement->default_label != NULL)
9193                 return;
9194
9195         determine_enum_values(enumt);
9196
9197         /* FIXME: calculation of value should be done while parsing */
9198         /* TODO: quadratic algorithm here. Change to an n log n one */
9199         const entity_t *entry = enumt->enume->base.next;
9200         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9201              entry = entry->base.next) {
9202                 ir_tarval *value = entry->enum_value.tv;
9203                 bool       found = false;
9204                 for (const case_label_statement_t *l = statement->first_case; l != NULL;
9205                      l = l->next) {
9206                         if (l->expression == NULL)
9207                                 continue;
9208                         if (l->first_case == l->last_case && l->first_case != value)
9209                                 continue;
9210                         if ((tarval_cmp(l->first_case, value) & ir_relation_less_equal)
9211                          && (tarval_cmp(value, l->last_case) & ir_relation_less_equal)) {
9212                                 found = true;
9213                                 break;
9214                         }
9215                 }
9216                 if (!found) {
9217                         position_t const *const pos = &statement->base.pos;
9218                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9219                 }
9220         }
9221 }
9222
9223 /**
9224  * Parse a switch statement.
9225  */
9226 static statement_t *parse_switch(void)
9227 {
9228         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9229
9230         eat(T_switch);
9231
9232         PUSH_PARENT(statement);
9233         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9234
9235         expression_t *const expr = parse_condition();
9236         type_t       *      type = skip_typeref(expr->base.type);
9237         if (is_type_integer(type)) {
9238                 type = promote_integer(type);
9239                 if (get_akind_rank(get_arithmetic_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9240                         warningf(WARN_TRADITIONAL, &expr->base.pos,
9241                                  "'%T' switch expression not converted to '%T' in ISO C",
9242                                  type, type_int);
9243                 }
9244         } else if (is_type_valid(type)) {
9245                 errorf(&expr->base.pos, "switch quantity is not an integer, but '%T'",
9246                        type);
9247                 type = type_error_type;
9248         }
9249         statement->switchs.expression = create_implicit_cast(expr, type);
9250
9251         switch_statement_t *rem = current_switch;
9252         current_switch          = &statement->switchs;
9253         statement->switchs.body = parse_inner_statement();
9254         current_switch          = rem;
9255
9256         if (statement->switchs.default_label == NULL) {
9257                 warningf(WARN_SWITCH_DEFAULT, &statement->base.pos, "switch has no default case");
9258         }
9259         check_enum_cases(&statement->switchs);
9260
9261         POP_SCOPE();
9262         POP_PARENT();
9263         return statement;
9264 }
9265
9266 static statement_t *parse_loop_body(statement_t *const loop)
9267 {
9268         statement_t *const rem = current_loop;
9269         current_loop = loop;
9270
9271         statement_t *const body = parse_inner_statement();
9272
9273         current_loop = rem;
9274         return body;
9275 }
9276
9277 /**
9278  * Parse a while statement.
9279  */
9280 static statement_t *parse_while(void)
9281 {
9282         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9283
9284         eat(T_while);
9285
9286         PUSH_PARENT(statement);
9287         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9288
9289         expression_t *const cond = parse_condition();
9290         statement->fors.condition = cond;
9291         /* §6.8.5:2    The controlling expression of an iteration statement shall
9292          *             have scalar type. */
9293         semantic_condition(cond, "condition of 'while'-statement");
9294
9295         statement->fors.body = parse_loop_body(statement);
9296
9297         POP_SCOPE();
9298         POP_PARENT();
9299         return statement;
9300 }
9301
9302 /**
9303  * Parse a do statement.
9304  */
9305 static statement_t *parse_do(void)
9306 {
9307         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9308
9309         eat(T_do);
9310
9311         PUSH_PARENT(statement);
9312         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9313
9314         add_anchor_token(T_while);
9315         statement->do_while.body = parse_loop_body(statement);
9316         rem_anchor_token(T_while);
9317
9318         expect(T_while);
9319         expression_t *const cond = parse_condition();
9320         statement->do_while.condition = cond;
9321         /* §6.8.5:2    The controlling expression of an iteration statement shall
9322          *             have scalar type. */
9323         semantic_condition(cond, "condition of 'do-while'-statement");
9324         expect(';');
9325
9326         POP_SCOPE();
9327         POP_PARENT();
9328         return statement;
9329 }
9330
9331 /**
9332  * Parse a for statement.
9333  */
9334 static statement_t *parse_for(void)
9335 {
9336         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9337
9338         eat(T_for);
9339
9340         PUSH_PARENT(statement);
9341         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9342
9343         add_anchor_token(')');
9344         expect('(');
9345
9346         PUSH_EXTENSION();
9347
9348         if (accept(';')) {
9349         } else if (is_declaration_specifier(&token)) {
9350                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9351         } else {
9352                 add_anchor_token(';');
9353                 expression_t *const init = parse_expression();
9354                 statement->fors.initialisation = init;
9355                 mark_vars_read(init, ENT_ANY);
9356                 if (!expression_has_effect(init)) {
9357                         warningf(WARN_UNUSED_VALUE, &init->base.pos, "initialisation of 'for'-statement has no effect");
9358                 }
9359                 rem_anchor_token(';');
9360                 expect(';');
9361         }
9362
9363         POP_EXTENSION();
9364
9365         if (token.kind != ';') {
9366                 add_anchor_token(';');
9367                 expression_t *const cond = parse_expression();
9368                 statement->fors.condition = cond;
9369                 /* §6.8.5:2    The controlling expression of an iteration statement
9370                  *             shall have scalar type. */
9371                 semantic_condition(cond, "condition of 'for'-statement");
9372                 mark_vars_read(cond, NULL);
9373                 rem_anchor_token(';');
9374         }
9375         expect(';');
9376         if (token.kind != ')') {
9377                 expression_t *const step = parse_expression();
9378                 statement->fors.step = step;
9379                 mark_vars_read(step, ENT_ANY);
9380                 if (!expression_has_effect(step)) {
9381                         warningf(WARN_UNUSED_VALUE, &step->base.pos, "step of 'for'-statement has no effect");
9382                 }
9383         }
9384         rem_anchor_token(')');
9385         expect(')');
9386         statement->fors.body = parse_loop_body(statement);
9387
9388         POP_SCOPE();
9389         POP_PARENT();
9390         return statement;
9391 }
9392
9393 /**
9394  * Parse a goto statement.
9395  */
9396 static statement_t *parse_goto(void)
9397 {
9398         statement_t *statement;
9399         if (GNU_MODE && look_ahead(1)->kind == '*') {
9400                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9401                 eat(T_goto);
9402                 eat('*');
9403
9404                 expression_t *expression = parse_expression();
9405                 mark_vars_read(expression, NULL);
9406
9407                 /* Argh: although documentation says the expression must be of type void*,
9408                  * gcc accepts anything that can be casted into void* without error */
9409                 type_t *type = expression->base.type;
9410
9411                 if (type != type_error_type) {
9412                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9413                                 errorf(&expression->base.pos, "cannot convert to a pointer type");
9414                         } else if (type != type_void_ptr) {
9415                                 warningf(WARN_OTHER, &expression->base.pos, "type of computed goto expression should be 'void*' not '%T'", type);
9416                         }
9417                         expression = create_implicit_cast(expression, type_void_ptr);
9418                 }
9419
9420                 statement->computed_goto.expression = expression;
9421         } else {
9422                 statement = allocate_statement_zero(STATEMENT_GOTO);
9423                 eat(T_goto);
9424
9425                 label_t *const label = get_label("while parsing goto");
9426                 if (label) {
9427                         label->n_users        += 1;
9428                         label->used            = true;
9429                         statement->gotos.label = label;
9430
9431                         /* remember the goto's in a list for later checking */
9432                         *goto_anchor = &statement->gotos;
9433                         goto_anchor  = &statement->gotos.next;
9434                 } else {
9435                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_position)->label;
9436                 }
9437         }
9438
9439         expect(';');
9440         return statement;
9441 }
9442
9443 /**
9444  * Parse a continue statement.
9445  */
9446 static statement_t *parse_continue(void)
9447 {
9448         if (current_loop == NULL) {
9449                 errorf(HERE, "continue statement not within loop");
9450         }
9451
9452         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9453
9454         eat(T_continue);
9455         expect(';');
9456         return statement;
9457 }
9458
9459 /**
9460  * Parse a break statement.
9461  */
9462 static statement_t *parse_break(void)
9463 {
9464         if (current_switch == NULL && current_loop == NULL) {
9465                 errorf(HERE, "break statement not within loop or switch");
9466         }
9467
9468         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9469
9470         eat(T_break);
9471         expect(';');
9472         return statement;
9473 }
9474
9475 /**
9476  * Parse a __leave statement.
9477  */
9478 static statement_t *parse_leave_statement(void)
9479 {
9480         if (current_try == NULL) {
9481                 errorf(HERE, "__leave statement not within __try");
9482         }
9483
9484         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9485
9486         eat(T___leave);
9487         expect(';');
9488         return statement;
9489 }
9490
9491 /**
9492  * Check if a given entity represents a local variable.
9493  */
9494 static bool is_local_variable(const entity_t *entity)
9495 {
9496         if (entity->kind != ENTITY_VARIABLE)
9497                 return false;
9498
9499         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9500         case STORAGE_CLASS_AUTO:
9501         case STORAGE_CLASS_REGISTER: {
9502                 const type_t *type = skip_typeref(entity->declaration.type);
9503                 if (is_type_function(type)) {
9504                         return false;
9505                 } else {
9506                         return true;
9507                 }
9508         }
9509         default:
9510                 return false;
9511         }
9512 }
9513
9514 /**
9515  * Check if a given expression represents a local variable.
9516  */
9517 static bool expression_is_local_variable(const expression_t *expression)
9518 {
9519         if (expression->base.kind != EXPR_REFERENCE) {
9520                 return false;
9521         }
9522         const entity_t *entity = expression->reference.entity;
9523         return is_local_variable(entity);
9524 }
9525
9526 static void err_or_warn(position_t const *const pos, char const *const msg)
9527 {
9528         if (c_mode & _CXX || strict_mode) {
9529                 errorf(pos, msg);
9530         } else {
9531                 warningf(WARN_OTHER, pos, msg);
9532         }
9533 }
9534
9535 /**
9536  * Parse a return statement.
9537  */
9538 static statement_t *parse_return(void)
9539 {
9540         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9541         eat(T_return);
9542
9543         expression_t *return_value = NULL;
9544         if (token.kind != ';') {
9545                 return_value = parse_expression();
9546                 mark_vars_read(return_value, NULL);
9547         }
9548
9549         const type_t *const func_type = skip_typeref(current_function->base.type);
9550         assert(is_type_function(func_type));
9551         type_t *const return_type = skip_typeref(func_type->function.return_type);
9552
9553         position_t const *const pos = &statement->base.pos;
9554         if (return_value != NULL) {
9555                 type_t *return_value_type = skip_typeref(return_value->base.type);
9556
9557                 if (is_type_void(return_type)) {
9558                         if (!is_type_void(return_value_type)) {
9559                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9560                                 /* Only warn in C mode, because GCC does the same */
9561                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9562                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9563                                 /* Only warn in C mode, because GCC does the same */
9564                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9565                         }
9566                 } else {
9567                         assign_error_t error = semantic_assign(return_type, return_value);
9568                         report_assign_error(error, return_type, return_value, "'return'",
9569                                             pos);
9570                 }
9571                 return_value = create_implicit_cast(return_value, return_type);
9572                 /* check for returning address of a local var */
9573                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9574                         const expression_t *expression = return_value->unary.value;
9575                         if (expression_is_local_variable(expression)) {
9576                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9577                         }
9578                 }
9579         } else if (!is_type_void(return_type)) {
9580                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9581                 err_or_warn(pos, "'return' without value, in function returning non-void");
9582         }
9583         statement->returns.value = return_value;
9584
9585         expect(';');
9586         return statement;
9587 }
9588
9589 /**
9590  * Parse a declaration statement.
9591  */
9592 static statement_t *parse_declaration_statement(void)
9593 {
9594         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9595
9596         entity_t *before = current_scope->last_entity;
9597         if (GNU_MODE) {
9598                 parse_external_declaration();
9599         } else {
9600                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9601         }
9602
9603         declaration_statement_t *const decl  = &statement->declaration;
9604         entity_t                *const begin =
9605                 before != NULL ? before->base.next : current_scope->entities;
9606         decl->declarations_begin = begin;
9607         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9608
9609         return statement;
9610 }
9611
9612 /**
9613  * Parse an expression statement, i.e. expr ';'.
9614  */
9615 static statement_t *parse_expression_statement(void)
9616 {
9617         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9618
9619         expression_t *const expr         = parse_expression();
9620         statement->expression.expression = expr;
9621         mark_vars_read(expr, ENT_ANY);
9622
9623         expect(';');
9624         return statement;
9625 }
9626
9627 /**
9628  * Parse a microsoft __try { } __finally { } or
9629  * __try{ } __except() { }
9630  */
9631 static statement_t *parse_ms_try_statment(void)
9632 {
9633         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9634         eat(T___try);
9635
9636         PUSH_PARENT(statement);
9637
9638         ms_try_statement_t *rem = current_try;
9639         current_try = &statement->ms_try;
9640         statement->ms_try.try_statement = parse_compound_statement(false);
9641         current_try = rem;
9642
9643         POP_PARENT();
9644
9645         if (accept(T___except)) {
9646                 expression_t *const expr = parse_condition();
9647                 type_t       *      type = skip_typeref(expr->base.type);
9648                 if (is_type_integer(type)) {
9649                         type = promote_integer(type);
9650                 } else if (is_type_valid(type)) {
9651                         errorf(&expr->base.pos,
9652                                "__expect expression is not an integer, but '%T'", type);
9653                         type = type_error_type;
9654                 }
9655                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9656         } else if (!accept(T__finally)) {
9657                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9658         }
9659         statement->ms_try.final_statement = parse_compound_statement(false);
9660         return statement;
9661 }
9662
9663 static statement_t *parse_empty_statement(void)
9664 {
9665         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9666         statement_t *const statement = create_empty_statement();
9667         eat(';');
9668         return statement;
9669 }
9670
9671 static statement_t *parse_local_label_declaration(void)
9672 {
9673         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9674
9675         eat(T___label__);
9676
9677         entity_t *begin   = NULL;
9678         entity_t *end     = NULL;
9679         entity_t **anchor = &begin;
9680         add_anchor_token(';');
9681         add_anchor_token(',');
9682         do {
9683                 position_t pos;
9684                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9685                 if (symbol) {
9686                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9687                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9688                                 position_t const *const ppos = &entity->base.pos;
9689                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9690                         } else {
9691                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9692                                 entity->base.parent_scope = current_scope;
9693
9694                                 *anchor = entity;
9695                                 anchor  = &entity->base.next;
9696                                 end     = entity;
9697
9698                                 environment_push(entity);
9699                         }
9700                 }
9701         } while (accept(','));
9702         rem_anchor_token(',');
9703         rem_anchor_token(';');
9704         expect(';');
9705         statement->declaration.declarations_begin = begin;
9706         statement->declaration.declarations_end   = end;
9707         return statement;
9708 }
9709
9710 static void parse_namespace_definition(void)
9711 {
9712         eat(T_namespace);
9713
9714         entity_t *entity = NULL;
9715         symbol_t *symbol = NULL;
9716
9717         if (token.kind == T_IDENTIFIER) {
9718                 symbol = token.base.symbol;
9719                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9720                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9721                         entity = NULL;
9722                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9723                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9724                         }
9725                 }
9726                 eat(T_IDENTIFIER);
9727         }
9728
9729         if (entity == NULL) {
9730                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9731                 entity->base.parent_scope = current_scope;
9732         }
9733
9734         if (token.kind == '=') {
9735                 /* TODO: parse namespace alias */
9736                 panic("namespace alias definition not supported yet");
9737         }
9738
9739         environment_push(entity);
9740         append_entity(current_scope, entity);
9741
9742         PUSH_SCOPE(&entity->namespacee.members);
9743         PUSH_CURRENT_ENTITY(entity);
9744
9745         add_anchor_token('}');
9746         expect('{');
9747         parse_externals();
9748         rem_anchor_token('}');
9749         expect('}');
9750
9751         POP_CURRENT_ENTITY();
9752         POP_SCOPE();
9753 }
9754
9755 /**
9756  * Parse a statement.
9757  * There's also parse_statement() which additionally checks for
9758  * "statement has no effect" warnings
9759  */
9760 static statement_t *intern_parse_statement(void)
9761 {
9762         /* declaration or statement */
9763         statement_t *statement;
9764         switch (token.kind) {
9765         case T_IDENTIFIER: {
9766                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9767                 if (la1_type == ':') {
9768                         statement = parse_label_statement();
9769                 } else if (is_typedef_symbol(token.base.symbol)) {
9770                         statement = parse_declaration_statement();
9771                 } else {
9772                         /* it's an identifier, the grammar says this must be an
9773                          * expression statement. However it is common that users mistype
9774                          * declaration types, so we guess a bit here to improve robustness
9775                          * for incorrect programs */
9776                         switch (la1_type) {
9777                         case '&':
9778                         case '*':
9779                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9780                         default:
9781                                         statement = parse_expression_statement();
9782                                 } else {
9783                         DECLARATION_START
9784                         case T_IDENTIFIER:
9785                                         statement = parse_declaration_statement();
9786                                 }
9787                                 break;
9788                         }
9789                 }
9790                 break;
9791         }
9792
9793         case T___extension__: {
9794                 /* This can be a prefix to a declaration or an expression statement.
9795                  * We simply eat it now and parse the rest with tail recursion. */
9796                 PUSH_EXTENSION();
9797                 statement = intern_parse_statement();
9798                 POP_EXTENSION();
9799                 break;
9800         }
9801
9802         DECLARATION_START
9803                 statement = parse_declaration_statement();
9804                 break;
9805
9806         case T___label__:
9807                 statement = parse_local_label_declaration();
9808                 break;
9809
9810         case ';':         statement = parse_empty_statement();         break;
9811         case '{':         statement = parse_compound_statement(false); break;
9812         case T___leave:   statement = parse_leave_statement();         break;
9813         case T___try:     statement = parse_ms_try_statment();         break;
9814         case T_asm:       statement = parse_asm_statement();           break;
9815         case T_break:     statement = parse_break();                   break;
9816         case T_case:      statement = parse_case_statement();          break;
9817         case T_continue:  statement = parse_continue();                break;
9818         case T_default:   statement = parse_default_statement();       break;
9819         case T_do:        statement = parse_do();                      break;
9820         case T_for:       statement = parse_for();                     break;
9821         case T_goto:      statement = parse_goto();                    break;
9822         case T_if:        statement = parse_if();                      break;
9823         case T_return:    statement = parse_return();                  break;
9824         case T_switch:    statement = parse_switch();                  break;
9825         case T_while:     statement = parse_while();                   break;
9826
9827         EXPRESSION_START
9828                 statement = parse_expression_statement();
9829                 break;
9830
9831         default:
9832                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9833                 statement = create_error_statement();
9834                 eat_until_anchor();
9835                 break;
9836         }
9837
9838         return statement;
9839 }
9840
9841 /**
9842  * parse a statement and emits "statement has no effect" warning if needed
9843  * (This is really a wrapper around intern_parse_statement with check for 1
9844  *  single warning. It is needed, because for statement expressions we have
9845  *  to avoid the warning on the last statement)
9846  */
9847 static statement_t *parse_statement(void)
9848 {
9849         statement_t *statement = intern_parse_statement();
9850
9851         if (statement->kind == STATEMENT_EXPRESSION) {
9852                 expression_t *expression = statement->expression.expression;
9853                 if (!expression_has_effect(expression)) {
9854                         warningf(WARN_UNUSED_VALUE, &expression->base.pos,
9855                                  "statement has no effect");
9856                 }
9857         }
9858
9859         return statement;
9860 }
9861
9862 /**
9863  * Parse a compound statement.
9864  */
9865 static statement_t *parse_compound_statement(bool inside_expression_statement)
9866 {
9867         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9868
9869         PUSH_PARENT(statement);
9870         PUSH_SCOPE(&statement->compound.scope);
9871
9872         eat('{');
9873         add_anchor_token('}');
9874         /* tokens, which can start a statement */
9875         /* TODO MS, __builtin_FOO */
9876         add_anchor_token('!');
9877         add_anchor_token('&');
9878         add_anchor_token('(');
9879         add_anchor_token('*');
9880         add_anchor_token('+');
9881         add_anchor_token('-');
9882         add_anchor_token(';');
9883         add_anchor_token('{');
9884         add_anchor_token('~');
9885         add_anchor_token(T_CHARACTER_CONSTANT);
9886         add_anchor_token(T_COLONCOLON);
9887         add_anchor_token(T_IDENTIFIER);
9888         add_anchor_token(T_MINUSMINUS);
9889         add_anchor_token(T_NUMBER);
9890         add_anchor_token(T_PLUSPLUS);
9891         add_anchor_token(T_STRING_LITERAL);
9892         add_anchor_token(T__Alignof);
9893         add_anchor_token(T__Bool);
9894         add_anchor_token(T__Complex);
9895         add_anchor_token(T__Imaginary);
9896         add_anchor_token(T__Thread_local);
9897         add_anchor_token(T___PRETTY_FUNCTION__);
9898         add_anchor_token(T___attribute__);
9899         add_anchor_token(T___builtin_va_start);
9900         add_anchor_token(T___extension__);
9901         add_anchor_token(T___func__);
9902         add_anchor_token(T___imag__);
9903         add_anchor_token(T___label__);
9904         add_anchor_token(T___real__);
9905         add_anchor_token(T_asm);
9906         add_anchor_token(T_auto);
9907         add_anchor_token(T_bool);
9908         add_anchor_token(T_break);
9909         add_anchor_token(T_case);
9910         add_anchor_token(T_char);
9911         add_anchor_token(T_class);
9912         add_anchor_token(T_const);
9913         add_anchor_token(T_const_cast);
9914         add_anchor_token(T_continue);
9915         add_anchor_token(T_default);
9916         add_anchor_token(T_delete);
9917         add_anchor_token(T_double);
9918         add_anchor_token(T_do);
9919         add_anchor_token(T_dynamic_cast);
9920         add_anchor_token(T_enum);
9921         add_anchor_token(T_extern);
9922         add_anchor_token(T_false);
9923         add_anchor_token(T_float);
9924         add_anchor_token(T_for);
9925         add_anchor_token(T_goto);
9926         add_anchor_token(T_if);
9927         add_anchor_token(T_inline);
9928         add_anchor_token(T_int);
9929         add_anchor_token(T_long);
9930         add_anchor_token(T_new);
9931         add_anchor_token(T_operator);
9932         add_anchor_token(T_register);
9933         add_anchor_token(T_reinterpret_cast);
9934         add_anchor_token(T_restrict);
9935         add_anchor_token(T_return);
9936         add_anchor_token(T_short);
9937         add_anchor_token(T_signed);
9938         add_anchor_token(T_sizeof);
9939         add_anchor_token(T_static);
9940         add_anchor_token(T_static_cast);
9941         add_anchor_token(T_struct);
9942         add_anchor_token(T_switch);
9943         add_anchor_token(T_template);
9944         add_anchor_token(T_this);
9945         add_anchor_token(T_throw);
9946         add_anchor_token(T_true);
9947         add_anchor_token(T_try);
9948         add_anchor_token(T_typedef);
9949         add_anchor_token(T_typeid);
9950         add_anchor_token(T_typename);
9951         add_anchor_token(T_typeof);
9952         add_anchor_token(T_union);
9953         add_anchor_token(T_unsigned);
9954         add_anchor_token(T_using);
9955         add_anchor_token(T_void);
9956         add_anchor_token(T_volatile);
9957         add_anchor_token(T_wchar_t);
9958         add_anchor_token(T_while);
9959
9960         statement_t **anchor            = &statement->compound.statements;
9961         bool          only_decls_so_far = true;
9962         while (token.kind != '}' && token.kind != T_EOF) {
9963                 statement_t *sub_statement = intern_parse_statement();
9964                 if (sub_statement->kind == STATEMENT_ERROR) {
9965                         break;
9966                 }
9967
9968                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9969                         only_decls_so_far = false;
9970                 } else if (!only_decls_so_far) {
9971                         position_t const *const pos = &sub_statement->base.pos;
9972                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9973                 }
9974
9975                 *anchor = sub_statement;
9976                 anchor  = &sub_statement->base.next;
9977         }
9978         expect('}');
9979
9980         /* look over all statements again to produce no effect warnings */
9981         if (is_warn_on(WARN_UNUSED_VALUE)) {
9982                 statement_t *sub_statement = statement->compound.statements;
9983                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9984                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9985                                 continue;
9986                         /* don't emit a warning for the last expression in an expression
9987                          * statement as it has always an effect */
9988                         if (inside_expression_statement && sub_statement->base.next == NULL)
9989                                 continue;
9990
9991                         expression_t *expression = sub_statement->expression.expression;
9992                         if (!expression_has_effect(expression)) {
9993                                 warningf(WARN_UNUSED_VALUE, &expression->base.pos,
9994                                          "statement has no effect");
9995                         }
9996                 }
9997         }
9998
9999         rem_anchor_token(T_while);
10000         rem_anchor_token(T_wchar_t);
10001         rem_anchor_token(T_volatile);
10002         rem_anchor_token(T_void);
10003         rem_anchor_token(T_using);
10004         rem_anchor_token(T_unsigned);
10005         rem_anchor_token(T_union);
10006         rem_anchor_token(T_typeof);
10007         rem_anchor_token(T_typename);
10008         rem_anchor_token(T_typeid);
10009         rem_anchor_token(T_typedef);
10010         rem_anchor_token(T_try);
10011         rem_anchor_token(T_true);
10012         rem_anchor_token(T_throw);
10013         rem_anchor_token(T_this);
10014         rem_anchor_token(T_template);
10015         rem_anchor_token(T_switch);
10016         rem_anchor_token(T_struct);
10017         rem_anchor_token(T_static_cast);
10018         rem_anchor_token(T_static);
10019         rem_anchor_token(T_sizeof);
10020         rem_anchor_token(T_signed);
10021         rem_anchor_token(T_short);
10022         rem_anchor_token(T_return);
10023         rem_anchor_token(T_restrict);
10024         rem_anchor_token(T_reinterpret_cast);
10025         rem_anchor_token(T_register);
10026         rem_anchor_token(T_operator);
10027         rem_anchor_token(T_new);
10028         rem_anchor_token(T_long);
10029         rem_anchor_token(T_int);
10030         rem_anchor_token(T_inline);
10031         rem_anchor_token(T_if);
10032         rem_anchor_token(T_goto);
10033         rem_anchor_token(T_for);
10034         rem_anchor_token(T_float);
10035         rem_anchor_token(T_false);
10036         rem_anchor_token(T_extern);
10037         rem_anchor_token(T_enum);
10038         rem_anchor_token(T_dynamic_cast);
10039         rem_anchor_token(T_do);
10040         rem_anchor_token(T_double);
10041         rem_anchor_token(T_delete);
10042         rem_anchor_token(T_default);
10043         rem_anchor_token(T_continue);
10044         rem_anchor_token(T_const_cast);
10045         rem_anchor_token(T_const);
10046         rem_anchor_token(T_class);
10047         rem_anchor_token(T_char);
10048         rem_anchor_token(T_case);
10049         rem_anchor_token(T_break);
10050         rem_anchor_token(T_bool);
10051         rem_anchor_token(T_auto);
10052         rem_anchor_token(T_asm);
10053         rem_anchor_token(T___real__);
10054         rem_anchor_token(T___label__);
10055         rem_anchor_token(T___imag__);
10056         rem_anchor_token(T___func__);
10057         rem_anchor_token(T___extension__);
10058         rem_anchor_token(T___builtin_va_start);
10059         rem_anchor_token(T___attribute__);
10060         rem_anchor_token(T___PRETTY_FUNCTION__);
10061         rem_anchor_token(T__Thread_local);
10062         rem_anchor_token(T__Imaginary);
10063         rem_anchor_token(T__Complex);
10064         rem_anchor_token(T__Bool);
10065         rem_anchor_token(T__Alignof);
10066         rem_anchor_token(T_STRING_LITERAL);
10067         rem_anchor_token(T_PLUSPLUS);
10068         rem_anchor_token(T_NUMBER);
10069         rem_anchor_token(T_MINUSMINUS);
10070         rem_anchor_token(T_IDENTIFIER);
10071         rem_anchor_token(T_COLONCOLON);
10072         rem_anchor_token(T_CHARACTER_CONSTANT);
10073         rem_anchor_token('~');
10074         rem_anchor_token('{');
10075         rem_anchor_token(';');
10076         rem_anchor_token('-');
10077         rem_anchor_token('+');
10078         rem_anchor_token('*');
10079         rem_anchor_token('(');
10080         rem_anchor_token('&');
10081         rem_anchor_token('!');
10082         rem_anchor_token('}');
10083
10084         POP_SCOPE();
10085         POP_PARENT();
10086         return statement;
10087 }
10088
10089 /**
10090  * Check for unused global static functions and variables
10091  */
10092 static void check_unused_globals(void)
10093 {
10094         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10095                 return;
10096
10097         for (const entity_t *entity = file_scope->entities; entity != NULL;
10098              entity = entity->base.next) {
10099                 if (!is_declaration(entity))
10100                         continue;
10101
10102                 const declaration_t *declaration = &entity->declaration;
10103                 if (declaration->used                  ||
10104                     declaration->modifiers & DM_UNUSED ||
10105                     declaration->modifiers & DM_USED   ||
10106                     declaration->storage_class != STORAGE_CLASS_STATIC)
10107                         continue;
10108
10109                 warning_t   why;
10110                 char const *s;
10111                 if (entity->kind == ENTITY_FUNCTION) {
10112                         /* inhibit warning for static inline functions */
10113                         if (entity->function.is_inline)
10114                                 continue;
10115
10116                         why = WARN_UNUSED_FUNCTION;
10117                         s   = entity->function.body != NULL ? "defined" : "declared";
10118                 } else {
10119                         why = WARN_UNUSED_VARIABLE;
10120                         s   = "defined";
10121                 }
10122
10123                 warningf(why, &declaration->base.pos, "'%#N' %s but not used", entity, s);
10124         }
10125 }
10126
10127 static void parse_global_asm(void)
10128 {
10129         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10130
10131         eat(T_asm);
10132         add_anchor_token(';');
10133         add_anchor_token(')');
10134         add_anchor_token(T_STRING_LITERAL);
10135         expect('(');
10136
10137         rem_anchor_token(T_STRING_LITERAL);
10138         statement->asms.asm_text = parse_string_literals("global asm");
10139         statement->base.next     = unit->global_asm;
10140         unit->global_asm         = statement;
10141
10142         rem_anchor_token(')');
10143         expect(')');
10144         rem_anchor_token(';');
10145         expect(';');
10146 }
10147
10148 static void parse_linkage_specification(void)
10149 {
10150         eat(T_extern);
10151
10152         position_t  const pos     = *HERE;
10153         char const *const linkage = parse_string_literals(NULL).begin;
10154
10155         linkage_kind_t old_linkage = current_linkage;
10156         linkage_kind_t new_linkage;
10157         if (streq(linkage, "C")) {
10158                 new_linkage = LINKAGE_C;
10159         } else if (streq(linkage, "C++")) {
10160                 new_linkage = LINKAGE_CXX;
10161         } else {
10162                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10163                 new_linkage = LINKAGE_C;
10164         }
10165         current_linkage = new_linkage;
10166
10167         if (accept('{')) {
10168                 parse_externals();
10169                 expect('}');
10170         } else {
10171                 parse_external();
10172         }
10173
10174         assert(current_linkage == new_linkage);
10175         current_linkage = old_linkage;
10176 }
10177
10178 static void parse_external(void)
10179 {
10180         switch (token.kind) {
10181                 case T_extern:
10182                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10183                                 parse_linkage_specification();
10184                         } else {
10185                 DECLARATION_START_NO_EXTERN
10186                 case T_IDENTIFIER:
10187                 case T___extension__:
10188                 /* tokens below are for implicit int */
10189                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10190                               implicit int) */
10191                 case '*':  /* * x; -> int* x; */
10192                 case '(':  /* (x); -> int (x); */
10193                                 PUSH_EXTENSION();
10194                                 parse_external_declaration();
10195                                 POP_EXTENSION();
10196                         }
10197                         return;
10198
10199                 case T_asm:
10200                         parse_global_asm();
10201                         return;
10202
10203                 case T_namespace:
10204                         parse_namespace_definition();
10205                         return;
10206
10207                 case ';':
10208                         if (!strict_mode) {
10209                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10210                                 eat(';');
10211                                 return;
10212                         }
10213                         /* FALLTHROUGH */
10214
10215                 default:
10216                         errorf(HERE, "stray %K outside of function", &token);
10217                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10218                                 eat_until_matching_token(token.kind);
10219                         next_token();
10220                         return;
10221         }
10222 }
10223
10224 static void parse_externals(void)
10225 {
10226         add_anchor_token('}');
10227         add_anchor_token(T_EOF);
10228
10229 #ifndef NDEBUG
10230         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10231         unsigned short token_anchor_copy[T_LAST_TOKEN];
10232         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10233 #endif
10234
10235         while (token.kind != T_EOF && token.kind != '}') {
10236 #ifndef NDEBUG
10237                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10238                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10239                         if (count != 0) {
10240                                 /* the anchor set and its copy differs */
10241                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10242                         }
10243                 }
10244                 if (in_gcc_extension) {
10245                         /* an gcc extension scope was not closed */
10246                         internal_errorf(HERE, "Leaked __extension__");
10247                 }
10248 #endif
10249
10250                 parse_external();
10251         }
10252
10253         rem_anchor_token(T_EOF);
10254         rem_anchor_token('}');
10255 }
10256
10257 /**
10258  * Parse a translation unit.
10259  */
10260 static void parse_translation_unit(void)
10261 {
10262         add_anchor_token(T_EOF);
10263
10264         while (true) {
10265                 parse_externals();
10266
10267                 if (token.kind == T_EOF)
10268                         break;
10269
10270                 errorf(HERE, "stray %K outside of function", &token);
10271                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10272                         eat_until_matching_token(token.kind);
10273                 next_token();
10274         }
10275 }
10276
10277 void set_default_visibility(elf_visibility_tag_t visibility)
10278 {
10279         default_visibility = visibility;
10280 }
10281
10282 /**
10283  * Parse the input.
10284  *
10285  * @return  the translation unit or NULL if errors occurred.
10286  */
10287 void start_parsing(void)
10288 {
10289         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10290         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10291
10292         print_to_file(stderr);
10293
10294         assert(unit == NULL);
10295         unit = allocate_ast_zero(sizeof(unit[0]));
10296
10297         assert(file_scope == NULL);
10298         file_scope = &unit->scope;
10299
10300         assert(current_scope == NULL);
10301         scope_push(&unit->scope);
10302
10303         create_gnu_builtins();
10304         if (c_mode & _MS)
10305                 create_microsoft_intrinsics();
10306 }
10307
10308 translation_unit_t *finish_parsing(void)
10309 {
10310         assert(current_scope == &unit->scope);
10311         scope_pop(NULL);
10312
10313         assert(file_scope == &unit->scope);
10314         check_unused_globals();
10315         file_scope = NULL;
10316
10317         DEL_ARR_F(environment_stack);
10318         DEL_ARR_F(label_stack);
10319
10320         translation_unit_t *result = unit;
10321         unit = NULL;
10322         return result;
10323 }
10324
10325 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10326  * are given length one. */
10327 static void complete_incomplete_arrays(void)
10328 {
10329         size_t n = ARR_LEN(incomplete_arrays);
10330         for (size_t i = 0; i != n; ++i) {
10331                 declaration_t *const decl = incomplete_arrays[i];
10332                 type_t        *const type = skip_typeref(decl->type);
10333
10334                 if (!is_type_incomplete(type))
10335                         continue;
10336
10337                 position_t const *const pos = &decl->base.pos;
10338                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10339
10340                 type_t *const new_type = duplicate_type(type);
10341                 new_type->array.size_constant     = true;
10342                 new_type->array.has_implicit_size = true;
10343                 new_type->array.size              = 1;
10344
10345                 type_t *const result = identify_new_type(new_type);
10346
10347                 decl->type = result;
10348         }
10349 }
10350
10351 static void prepare_main_collect2(entity_t *const entity)
10352 {
10353         PUSH_SCOPE(&entity->function.body->compound.scope);
10354
10355         // create call to __main
10356         symbol_t *symbol         = symbol_table_insert("__main");
10357         entity_t *subsubmain_ent
10358                 = create_implicit_function(symbol, &builtin_position);
10359
10360         expression_t *ref     = allocate_expression_zero(EXPR_REFERENCE);
10361         type_t       *ftype   = subsubmain_ent->declaration.type;
10362         ref->base.pos         = builtin_position;
10363         ref->base.type        = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10364         ref->reference.entity = subsubmain_ent;
10365
10366         expression_t *call  = allocate_expression_zero(EXPR_CALL);
10367         call->base.pos      = builtin_position;
10368         call->base.type     = type_void;
10369         call->call.function = ref;
10370
10371         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10372         expr_statement->base.pos              = builtin_position;
10373         expr_statement->expression.expression = call;
10374
10375         statement_t *const body = entity->function.body;
10376         assert(body->kind == STATEMENT_COMPOUND);
10377         compound_statement_t *compounds = &body->compound;
10378
10379         expr_statement->base.next = compounds->statements;
10380         compounds->statements     = expr_statement;
10381
10382         POP_SCOPE();
10383 }
10384
10385 void parse(void)
10386 {
10387         lookahead_bufpos = 0;
10388         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10389                 next_token();
10390         }
10391         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10392         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10393         parse_translation_unit();
10394         complete_incomplete_arrays();
10395         DEL_ARR_F(incomplete_arrays);
10396         incomplete_arrays = NULL;
10397 }
10398
10399 /**
10400  * Initialize the parser.
10401  */
10402 void init_parser(void)
10403 {
10404         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10405
10406         init_expression_parsers();
10407         obstack_init(&temp_obst);
10408 }
10409
10410 /**
10411  * Terminate the parser.
10412  */
10413 void exit_parser(void)
10414 {
10415         obstack_free(&temp_obst, NULL);
10416 }