nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "attribute_t.h"
  38 #include "lang_features.h"
  39 #include "walk_statements.h"
  40 #include "warning.h"
  41 #include "printer.h"
  42 #include "adt/bitfiddle.h"
  43 #include "adt/error.h"
  44 #include "adt/array.h"
  45
  46 //#define PRINT_TOKENS
  47 #define MAX_LOOKAHEAD 1
  48
  49 typedef struct {
  50         entity_t           *old_entity;
  51         symbol_t           *symbol;
  52         entity_namespace_t  namespc;
  53 } stack_entry_t;
  54
  55 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  56 struct declaration_specifiers_t {
  57         source_position_t  source_position;
  58         storage_class_t    storage_class;
  59         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  60         bool               is_inline    : 1;
  61         bool               thread_local : 1;  /**< GCC __thread */
  62         attribute_t       *attributes;        /**< list of attributes */
  63         type_t            *type;
  64 };
  65
  66 /**
  67  * An environment for parsing initializers (and compound literals).
  68  */
  69 typedef struct parse_initializer_env_t {
  70         type_t     *type;   /**< the type of the initializer. In case of an
  71                                  array type with unspecified size this gets
  72                                  adjusted to the actual size. */
  73         entity_t   *entity; /**< the variable that is initialized if any */
  74         bool        must_be_constant;
  75 } parse_initializer_env_t;
  76
  77 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  78
  79 /** The current token. */
  80 static token_t              token;
  81 /** The lookahead ring-buffer. */
  82 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  83 /** Position of the next token in the lookahead buffer. */
  84 static size_t               lookahead_bufpos;
  85 static stack_entry_t       *environment_stack = NULL;
  86 static stack_entry_t       *label_stack       = NULL;
  87 static scope_t             *file_scope        = NULL;
  88 static scope_t             *current_scope     = NULL;
  89 /** Point to the current function declaration if inside a function. */
  90 static function_t          *current_function  = NULL;
  91 static entity_t            *current_entity    = NULL;
  92 static entity_t            *current_init_decl = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in a type property context (evaluation only for type) */
 105 static bool                 in_type_prop      = false;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_PARENT(stmt)                          \
 115         statement_t *const prev_parent = current_parent; \
 116         ((void)(current_parent = (stmt)))
 117 #define POP_PARENT ((void)(current_parent = prev_parent))
 118
 119 /** special symbol used for anonymous entities. */
 120 static symbol_t *sym_anonymous = NULL;
 121
 122 /** The token anchor set */
 123 static unsigned char token_anchor_set[T_LAST_TOKEN];
 124
 125 /** The current source position. */
 126 #define HERE (&token.source_position)
 127
 128 /** true if we are in GCC mode. */
 129 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 130
 131 static statement_t *parse_compound_statement(bool inside_expression_statement);
 132 static statement_t *parse_statement(void);
 133
 134 static expression_t *parse_subexpression(precedence_t);
 135 static expression_t *parse_expression(void);
 136 static type_t       *parse_typename(void);
 137 static void          parse_externals(void);
 138 static void          parse_external(void);
 139
 140 static void parse_compound_type_entries(compound_t *compound_declaration);
 141
 142 static void check_call_argument(type_t          *expected_type,
 143                                                                 call_argument_t *argument, unsigned pos);
 144
 145 typedef enum declarator_flags_t {
 146         DECL_FLAGS_NONE             = 0,
 147         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 148         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 149         DECL_IS_PARAMETER           = 1U << 2
 150 } declarator_flags_t;
 151
 152 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 153                                   declarator_flags_t flags);
 154
 155 static void semantic_comparison(binary_expression_t *expression);
 156
 157 #define STORAGE_CLASSES       \
 158         STORAGE_CLASSES_NO_EXTERN \
 159         case T_extern:
 160
 161 #define STORAGE_CLASSES_NO_EXTERN \
 162         case T_typedef:         \
 163         case T_static:          \
 164         case T_auto:            \
 165         case T_register:        \
 166         case T___thread:
 167
 168 #define TYPE_QUALIFIERS     \
 169         case T_const:           \
 170         case T_restrict:        \
 171         case T_volatile:        \
 172         case T_inline:          \
 173         case T__forceinline:    \
 174         case T___attribute__:
 175
 176 #define COMPLEX_SPECIFIERS  \
 177         case T__Complex:
 178 #define IMAGINARY_SPECIFIERS \
 179         case T__Imaginary:
 180
 181 #define TYPE_SPECIFIERS       \
 182         case T__Bool:             \
 183         case T___builtin_va_list: \
 184         case T___typeof__:        \
 185         case T__declspec:         \
 186         case T_bool:              \
 187         case T_char:              \
 188         case T_double:            \
 189         case T_enum:              \
 190         case T_float:             \
 191         case T_int:               \
 192         case T_long:              \
 193         case T_short:             \
 194         case T_signed:            \
 195         case T_struct:            \
 196         case T_union:             \
 197         case T_unsigned:          \
 198         case T_void:              \
 199         case T_wchar_t:           \
 200         case T__int8:             \
 201         case T__int16:            \
 202         case T__int32:            \
 203         case T__int64:            \
 204         case T__int128:           \
 205         COMPLEX_SPECIFIERS        \
 206         IMAGINARY_SPECIFIERS
 207
 208 #define DECLARATION_START   \
 209         STORAGE_CLASSES         \
 210         TYPE_QUALIFIERS         \
 211         TYPE_SPECIFIERS
 212
 213 #define DECLARATION_START_NO_EXTERN \
 214         STORAGE_CLASSES_NO_EXTERN       \
 215         TYPE_QUALIFIERS                 \
 216         TYPE_SPECIFIERS
 217
 218 #define EXPRESSION_START              \
 219         case '!':                         \
 220         case '&':                         \
 221         case '(':                         \
 222         case '*':                         \
 223         case '+':                         \
 224         case '-':                         \
 225         case '~':                         \
 226         case T_ANDAND:                    \
 227         case T_CHARACTER_CONSTANT:        \
 228         case T_FLOATINGPOINT:             \
 229         case T_FLOATINGPOINT_HEXADECIMAL: \
 230         case T_INTEGER:                   \
 231         case T_INTEGER_HEXADECIMAL:       \
 232         case T_INTEGER_OCTAL:             \
 233         case T_MINUSMINUS:                \
 234         case T_PLUSPLUS:                  \
 235         case T_STRING_LITERAL:            \
 236         case T_WIDE_CHARACTER_CONSTANT:   \
 237         case T_WIDE_STRING_LITERAL:       \
 238         case T___FUNCDNAME__:             \
 239         case T___FUNCSIG__:               \
 240         case T___FUNCTION__:              \
 241         case T___PRETTY_FUNCTION__:       \
 242         case T___alignof__:               \
 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
 264 /**
 265  * Returns the size of a statement node.
 266  *
 267  * @param kind  the statement kind
 268  */
 269 static size_t get_statement_struct_size(statement_kind_t kind)
 270 {
 271         static const size_t sizes[] = {
 272                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 273                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 274                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 275                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 276                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 277                 [STATEMENT_IF]          = sizeof(if_statement_t),
 278                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 279                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 280                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 281                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 282                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 283                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 284                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 285                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 286                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 287                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 288                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 289                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 290                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 291         };
 292         assert((size_t)kind < lengthof(sizes));
 293         assert(sizes[kind] != 0);
 294         return sizes[kind];
 295 }
 296
 297 /**
 298  * Returns the size of an expression node.
 299  *
 300  * @param kind  the expression kind
 301  */
 302 static size_t get_expression_struct_size(expression_kind_t kind)
 303 {
 304         static const size_t sizes[] = {
 305                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 306                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 307                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 308                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 309                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 310                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 311                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 312                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 313                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 314                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 315                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 316                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 317                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 318                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 319                 [EXPR_CALL]                       = sizeof(call_expression_t),
 320                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 321                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 322                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 323                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 324                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 325                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 326                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 327                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 328                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 329                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 330                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 331                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 332                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 333                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 334                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 335                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 336                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 337         };
 338         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 339                 return sizes[EXPR_UNARY_FIRST];
 340         }
 341         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 342                 return sizes[EXPR_BINARY_FIRST];
 343         }
 344         assert((size_t)kind < lengthof(sizes));
 345         assert(sizes[kind] != 0);
 346         return sizes[kind];
 347 }
 348
 349 /**
 350  * Allocate a statement node of given kind and initialize all
 351  * fields with zero. Sets its source position to the position
 352  * of the current token.
 353  */
 354 static statement_t *allocate_statement_zero(statement_kind_t kind)
 355 {
 356         size_t       size = get_statement_struct_size(kind);
 357         statement_t *res  = allocate_ast_zero(size);
 358
 359         res->base.kind            = kind;
 360         res->base.parent          = current_parent;
 361         res->base.source_position = token.source_position;
 362         return res;
 363 }
 364
 365 /**
 366  * Allocate an expression node of given kind and initialize all
 367  * fields with zero.
 368  *
 369  * @param kind  the kind of the expression to allocate
 370  */
 371 static expression_t *allocate_expression_zero(expression_kind_t kind)
 372 {
 373         size_t        size = get_expression_struct_size(kind);
 374         expression_t *res  = allocate_ast_zero(size);
 375
 376         res->base.kind            = kind;
 377         res->base.type            = type_error_type;
 378         res->base.source_position = token.source_position;
 379         return res;
 380 }
 381
 382 /**
 383  * Creates a new invalid expression at the source position
 384  * of the current token.
 385  */
 386 static expression_t *create_invalid_expression(void)
 387 {
 388         return allocate_expression_zero(EXPR_INVALID);
 389 }
 390
 391 /**
 392  * Creates a new invalid statement.
 393  */
 394 static statement_t *create_invalid_statement(void)
 395 {
 396         return allocate_statement_zero(STATEMENT_INVALID);
 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 static function_parameter_t *allocate_parameter(type_t *const type)
 408 {
 409         function_parameter_t *const param
 410                 = obstack_alloc(type_obst, sizeof(*param));
 411         memset(param, 0, sizeof(*param));
 412         param->type = type;
 413         return param;
 414 }
 415
 416 /**
 417  * Returns the size of an initializer node.
 418  *
 419  * @param kind  the initializer kind
 420  */
 421 static size_t get_initializer_size(initializer_kind_t kind)
 422 {
 423         static const size_t sizes[] = {
 424                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 425                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 426                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 427                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 428                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 429         };
 430         assert((size_t)kind < lengthof(sizes));
 431         assert(sizes[kind] != 0);
 432         return sizes[kind];
 433 }
 434
 435 /**
 436  * Allocate an initializer node of given kind and initialize all
 437  * fields with zero.
 438  */
 439 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 440 {
 441         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 442         result->kind          = kind;
 443
 444         return result;
 445 }
 446
 447 /**
 448  * Returns the index of the top element of the environment stack.
 449  */
 450 static size_t environment_top(void)
 451 {
 452         return ARR_LEN(environment_stack);
 453 }
 454
 455 /**
 456  * Returns the index of the top element of the global label stack.
 457  */
 458 static size_t label_top(void)
 459 {
 460         return ARR_LEN(label_stack);
 461 }
 462
 463 /**
 464  * Return the next token.
 465  */
 466 static inline void next_token(void)
 467 {
 468         token                              = lookahead_buffer[lookahead_bufpos];
 469         lookahead_buffer[lookahead_bufpos] = lexer_token;
 470         lexer_next_token();
 471
 472         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 473
 474 #ifdef PRINT_TOKENS
 475         print_token(stderr, &token);
 476         fprintf(stderr, "\n");
 477 #endif
 478 }
 479
 480 static inline bool next_if(int const type)
 481 {
 482         if (token.type == type) {
 483                 next_token();
 484                 return true;
 485         } else {
 486                 return false;
 487         }
 488 }
 489
 490 /**
 491  * Return the next token with a given lookahead.
 492  */
 493 static inline const token_t *look_ahead(size_t num)
 494 {
 495         assert(0 < num && num <= MAX_LOOKAHEAD);
 496         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 497         return &lookahead_buffer[pos];
 498 }
 499
 500 /**
 501  * Adds a token type to the token type anchor set (a multi-set).
 502  */
 503 static void add_anchor_token(int token_type)
 504 {
 505         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 506         ++token_anchor_set[token_type];
 507 }
 508
 509 /**
 510  * Set the number of tokens types of the given type
 511  * to zero and return the old count.
 512  */
 513 static int save_and_reset_anchor_state(int token_type)
 514 {
 515         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 516         int count = token_anchor_set[token_type];
 517         token_anchor_set[token_type] = 0;
 518         return count;
 519 }
 520
 521 /**
 522  * Restore the number of token types to the given count.
 523  */
 524 static void restore_anchor_state(int token_type, int count)
 525 {
 526         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 527         token_anchor_set[token_type] = count;
 528 }
 529
 530 /**
 531  * Remove a token type from the token type anchor set (a multi-set).
 532  */
 533 static void rem_anchor_token(int token_type)
 534 {
 535         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 536         assert(token_anchor_set[token_type] != 0);
 537         --token_anchor_set[token_type];
 538 }
 539
 540 /**
 541  * Return true if the token type of the current token is
 542  * in the anchor set.
 543  */
 544 static bool at_anchor(void)
 545 {
 546         if (token.type < 0)
 547                 return false;
 548         return token_anchor_set[token.type];
 549 }
 550
 551 /**
 552  * Eat tokens until a matching token type is found.
 553  */
 554 static void eat_until_matching_token(int type)
 555 {
 556         int end_token;
 557         switch (type) {
 558                 case '(': end_token = ')';  break;
 559                 case '{': end_token = '}';  break;
 560                 case '[': end_token = ']';  break;
 561                 default:  end_token = type; break;
 562         }
 563
 564         unsigned parenthesis_count = 0;
 565         unsigned brace_count       = 0;
 566         unsigned bracket_count     = 0;
 567         while (token.type        != end_token ||
 568                parenthesis_count != 0         ||
 569                brace_count       != 0         ||
 570                bracket_count     != 0) {
 571                 switch (token.type) {
 572                 case T_EOF: return;
 573                 case '(': ++parenthesis_count; break;
 574                 case '{': ++brace_count;       break;
 575                 case '[': ++bracket_count;     break;
 576
 577                 case ')':
 578                         if (parenthesis_count > 0)
 579                                 --parenthesis_count;
 580                         goto check_stop;
 581
 582                 case '}':
 583                         if (brace_count > 0)
 584                                 --brace_count;
 585                         goto check_stop;
 586
 587                 case ']':
 588                         if (bracket_count > 0)
 589                                 --bracket_count;
 590 check_stop:
 591                         if (token.type        == end_token &&
 592                             parenthesis_count == 0         &&
 593                             brace_count       == 0         &&
 594                             bracket_count     == 0)
 595                                 return;
 596                         break;
 597
 598                 default:
 599                         break;
 600                 }
 601                 next_token();
 602         }
 603 }
 604
 605 /**
 606  * Eat input tokens until an anchor is found.
 607  */
 608 static void eat_until_anchor(void)
 609 {
 610         while (token_anchor_set[token.type] == 0) {
 611                 if (token.type == '(' || token.type == '{' || token.type == '[')
 612                         eat_until_matching_token(token.type);
 613                 next_token();
 614         }
 615 }
 616
 617 /**
 618  * Eat a whole block from input tokens.
 619  */
 620 static void eat_block(void)
 621 {
 622         eat_until_matching_token('{');
 623         next_if('}');
 624 }
 625
 626 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 627
 628 /**
 629  * Report a parse error because an expected token was not found.
 630  */
 631 static
 632 #if defined __GNUC__ && __GNUC__ >= 4
 633 __attribute__((sentinel))
 634 #endif
 635 void parse_error_expected(const char *message, ...)
 636 {
 637         if (message != NULL) {
 638                 errorf(HERE, "%s", message);
 639         }
 640         va_list ap;
 641         va_start(ap, message);
 642         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 643         va_end(ap);
 644 }
 645
 646 /**
 647  * Report an incompatible type.
 648  */
 649 static void type_error_incompatible(const char *msg,
 650                 const source_position_t *source_position, type_t *type1, type_t *type2)
 651 {
 652         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 653                msg, type1, type2);
 654 }
 655
 656 /**
 657  * Expect the current token is the expected token.
 658  * If not, generate an error, eat the current statement,
 659  * and goto the error_label label.
 660  */
 661 #define expect(expected, error_label)                     \
 662         do {                                                  \
 663                 if (UNLIKELY(token.type != (expected))) {         \
 664                         parse_error_expected(NULL, (expected), NULL); \
 665                         add_anchor_token(expected);                   \
 666                         eat_until_anchor();                           \
 667                         next_if((expected));                          \
 668                         rem_anchor_token(expected);                   \
 669                         goto error_label;                             \
 670                 }                                                 \
 671                 next_token();                                     \
 672         } while (0)
 673
 674 /**
 675  * Push a given scope on the scope stack and make it the
 676  * current scope
 677  */
 678 static scope_t *scope_push(scope_t *new_scope)
 679 {
 680         if (current_scope != NULL) {
 681                 new_scope->depth = current_scope->depth + 1;
 682         }
 683
 684         scope_t *old_scope = current_scope;
 685         current_scope      = new_scope;
 686         return old_scope;
 687 }
 688
 689 /**
 690  * Pop the current scope from the scope stack.
 691  */
 692 static void scope_pop(scope_t *old_scope)
 693 {
 694         current_scope = old_scope;
 695 }
 696
 697 /**
 698  * Search an entity by its symbol in a given namespace.
 699  */
 700 static entity_t *get_entity(const symbol_t *const symbol,
 701                             namespace_tag_t namespc)
 702 {
 703         assert(namespc != NAMESPACE_INVALID);
 704         entity_t *entity = symbol->entity;
 705         for (; entity != NULL; entity = entity->base.symbol_next) {
 706                 if ((namespace_tag_t)entity->base.namespc == namespc)
 707                         return entity;
 708         }
 709
 710         return NULL;
 711 }
 712
 713 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 714  * possible. */
 715 static entity_t *get_tag(symbol_t const *const symbol,
 716                          entity_kind_tag_t const kind)
 717 {
 718         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 719         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 720                 errorf(HERE,
 721                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 722                                 symbol, &entity->base.source_position);
 723                 entity = NULL;
 724         }
 725         return entity;
 726 }
 727
 728 /**
 729  * pushs an entity on the environment stack and links the corresponding symbol
 730  * it.
 731  */
 732 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 733 {
 734         symbol_t           *symbol  = entity->base.symbol;
 735         entity_namespace_t  namespc = entity->base.namespc;
 736         assert(namespc != NAMESPACE_INVALID);
 737
 738         /* replace/add entity into entity list of the symbol */
 739         entity_t **anchor;
 740         entity_t  *iter;
 741         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 742                 iter = *anchor;
 743                 if (iter == NULL)
 744                         break;
 745
 746                 /* replace an entry? */
 747                 if (iter->base.namespc == namespc) {
 748                         entity->base.symbol_next = iter->base.symbol_next;
 749                         break;
 750                 }
 751         }
 752         *anchor = entity;
 753
 754         /* remember old declaration */
 755         stack_entry_t entry;
 756         entry.symbol     = symbol;
 757         entry.old_entity = iter;
 758         entry.namespc    = namespc;
 759         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 760 }
 761
 762 /**
 763  * Push an entity on the environment stack.
 764  */
 765 static void environment_push(entity_t *entity)
 766 {
 767         assert(entity->base.source_position.input_name != NULL);
 768         assert(entity->base.parent_scope != NULL);
 769         stack_push(&environment_stack, entity);
 770 }
 771
 772 /**
 773  * Push a declaration on the global label stack.
 774  *
 775  * @param declaration  the declaration
 776  */
 777 static void label_push(entity_t *label)
 778 {
 779         /* we abuse the parameters scope as parent for the labels */
 780         label->base.parent_scope = &current_function->parameters;
 781         stack_push(&label_stack, label);
 782 }
 783
 784 /**
 785  * pops symbols from the environment stack until @p new_top is the top element
 786  */
 787 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 788 {
 789         stack_entry_t *stack = *stack_ptr;
 790         size_t         top   = ARR_LEN(stack);
 791         size_t         i;
 792
 793         assert(new_top <= top);
 794         if (new_top == top)
 795                 return;
 796
 797         for (i = top; i > new_top; --i) {
 798                 stack_entry_t *entry = &stack[i - 1];
 799
 800                 entity_t           *old_entity = entry->old_entity;
 801                 symbol_t           *symbol     = entry->symbol;
 802                 entity_namespace_t  namespc    = entry->namespc;
 803
 804                 /* replace with old_entity/remove */
 805                 entity_t **anchor;
 806                 entity_t  *iter;
 807                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 808                         iter = *anchor;
 809                         assert(iter != NULL);
 810                         /* replace an entry? */
 811                         if (iter->base.namespc == namespc)
 812                                 break;
 813                 }
 814
 815                 /* restore definition from outer scopes (if there was one) */
 816                 if (old_entity != NULL) {
 817                         old_entity->base.symbol_next = iter->base.symbol_next;
 818                         *anchor                      = old_entity;
 819                 } else {
 820                         /* remove entry from list */
 821                         *anchor = iter->base.symbol_next;
 822                 }
 823         }
 824
 825         ARR_SHRINKLEN(*stack_ptr, new_top);
 826 }
 827
 828 /**
 829  * Pop all entries from the environment stack until the new_top
 830  * is reached.
 831  *
 832  * @param new_top  the new stack top
 833  */
 834 static void environment_pop_to(size_t new_top)
 835 {
 836         stack_pop_to(&environment_stack, new_top);
 837 }
 838
 839 /**
 840  * Pop all entries from the global label stack until the new_top
 841  * is reached.
 842  *
 843  * @param new_top  the new stack top
 844  */
 845 static void label_pop_to(size_t new_top)
 846 {
 847         stack_pop_to(&label_stack, new_top);
 848 }
 849
 850 static int get_akind_rank(atomic_type_kind_t akind)
 851 {
 852         return (int) akind;
 853 }
 854
 855 /**
 856  * Return the type rank for an atomic type.
 857  */
 858 static int get_rank(const type_t *type)
 859 {
 860         assert(!is_typeref(type));
 861         if (type->kind == TYPE_ENUM)
 862                 return get_akind_rank(type->enumt.akind);
 863
 864         assert(type->kind == TYPE_ATOMIC);
 865         return get_akind_rank(type->atomic.akind);
 866 }
 867
 868 /**
 869  * §6.3.1.1:2  Do integer promotion for a given type.
 870  *
 871  * @param type  the type to promote
 872  * @return the promoted type
 873  */
 874 static type_t *promote_integer(type_t *type)
 875 {
 876         if (type->kind == TYPE_BITFIELD)
 877                 type = type->bitfield.base_type;
 878
 879         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 880                 type = type_int;
 881
 882         return type;
 883 }
 884
 885 /**
 886  * Create a cast expression.
 887  *
 888  * @param expression  the expression to cast
 889  * @param dest_type   the destination type
 890  */
 891 static expression_t *create_cast_expression(expression_t *expression,
 892                                             type_t *dest_type)
 893 {
 894         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 895
 896         cast->unary.value = expression;
 897         cast->base.type   = dest_type;
 898
 899         return cast;
 900 }
 901
 902 /**
 903  * Check if a given expression represents a null pointer constant.
 904  *
 905  * @param expression  the expression to check
 906  */
 907 static bool is_null_pointer_constant(const expression_t *expression)
 908 {
 909         /* skip void* cast */
 910         if (expression->kind == EXPR_UNARY_CAST ||
 911                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 912                 type_t *const type = skip_typeref(expression->base.type);
 913                 if (types_compatible(type, type_void_ptr))
 914                         expression = expression->unary.value;
 915         }
 916
 917         type_t *const type = skip_typeref(expression->base.type);
 918         if (!is_type_integer(type))
 919                 return false;
 920         switch (is_constant_expression(expression)) {
 921                 case EXPR_CLASS_ERROR:    return true;
 922                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 923                 default:                  return false;
 924         }
 925 }
 926
 927 /**
 928  * Create an implicit cast expression.
 929  *
 930  * @param expression  the expression to cast
 931  * @param dest_type   the destination type
 932  */
 933 static expression_t *create_implicit_cast(expression_t *expression,
 934                                           type_t *dest_type)
 935 {
 936         type_t *const source_type = expression->base.type;
 937
 938         if (source_type == dest_type)
 939                 return expression;
 940
 941         return create_cast_expression(expression, dest_type);
 942 }
 943
 944 typedef enum assign_error_t {
 945         ASSIGN_SUCCESS,
 946         ASSIGN_ERROR_INCOMPATIBLE,
 947         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 948         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 949         ASSIGN_WARNING_POINTER_FROM_INT,
 950         ASSIGN_WARNING_INT_FROM_POINTER
 951 } assign_error_t;
 952
 953 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
 954                                 const expression_t *const right,
 955                                 const char *context,
 956                                 const source_position_t *source_position)
 957 {
 958         type_t *const orig_type_right = right->base.type;
 959         type_t *const type_left       = skip_typeref(orig_type_left);
 960         type_t *const type_right      = skip_typeref(orig_type_right);
 961
 962         switch (error) {
 963         case ASSIGN_SUCCESS:
 964                 return;
 965         case ASSIGN_ERROR_INCOMPATIBLE:
 966                 errorf(source_position,
 967                        "destination type '%T' in %s is incompatible with type '%T'",
 968                        orig_type_left, context, orig_type_right);
 969                 return;
 970
 971         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 972                 if (warning.other) {
 973                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 974                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 975
 976                         /* the left type has all qualifiers from the right type */
 977                         unsigned missing_qualifiers
 978                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 979                         warningf(source_position,
 980                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
 981                                         orig_type_left, context, orig_type_right, missing_qualifiers);
 982                 }
 983                 return;
 984         }
 985
 986         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 987                 if (warning.other) {
 988                         warningf(source_position,
 989                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 990                                         orig_type_left, context, right, orig_type_right);
 991                 }
 992                 return;
 993
 994         case ASSIGN_WARNING_POINTER_FROM_INT:
 995                 if (warning.other) {
 996                         warningf(source_position,
 997                                         "%s makes pointer '%T' from integer '%T' without a cast",
 998                                         context, orig_type_left, orig_type_right);
 999                 }
1000                 return;
1001
1002         case ASSIGN_WARNING_INT_FROM_POINTER:
1003                 if (warning.other) {
1004                         warningf(source_position,
1005                                         "%s makes integer '%T' from pointer '%T' without a cast",
1006                                         context, orig_type_left, orig_type_right);
1007                 }
1008                 return;
1009
1010         default:
1011                 panic("invalid error value");
1012         }
1013 }
1014
1015 /** Implements the rules from §6.5.16.1 */
1016 static assign_error_t semantic_assign(type_t *orig_type_left,
1017                                       const expression_t *const right)
1018 {
1019         type_t *const orig_type_right = right->base.type;
1020         type_t *const type_left       = skip_typeref(orig_type_left);
1021         type_t *const type_right      = skip_typeref(orig_type_right);
1022
1023         if (is_type_pointer(type_left)) {
1024                 if (is_null_pointer_constant(right)) {
1025                         return ASSIGN_SUCCESS;
1026                 } else if (is_type_pointer(type_right)) {
1027                         type_t *points_to_left
1028                                 = skip_typeref(type_left->pointer.points_to);
1029                         type_t *points_to_right
1030                                 = skip_typeref(type_right->pointer.points_to);
1031                         assign_error_t res = ASSIGN_SUCCESS;
1032
1033                         /* the left type has all qualifiers from the right type */
1034                         unsigned missing_qualifiers
1035                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1036                         if (missing_qualifiers != 0) {
1037                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1038                         }
1039
1040                         points_to_left  = get_unqualified_type(points_to_left);
1041                         points_to_right = get_unqualified_type(points_to_right);
1042
1043                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1044                                 return res;
1045
1046                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1047                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1048                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1049                         }
1050
1051                         if (!types_compatible(points_to_left, points_to_right)) {
1052                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1053                         }
1054
1055                         return res;
1056                 } else if (is_type_integer(type_right)) {
1057                         return ASSIGN_WARNING_POINTER_FROM_INT;
1058                 }
1059         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1060                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1061                                 && is_type_pointer(type_right))) {
1062                 return ASSIGN_SUCCESS;
1063         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1064                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1065                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1066                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1067                         return ASSIGN_SUCCESS;
1068                 }
1069         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1070                 return ASSIGN_WARNING_INT_FROM_POINTER;
1071         }
1072
1073         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1074                 return ASSIGN_SUCCESS;
1075
1076         return ASSIGN_ERROR_INCOMPATIBLE;
1077 }
1078
1079 static expression_t *parse_constant_expression(void)
1080 {
1081         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1082
1083         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1084                 errorf(&result->base.source_position,
1085                        "expression '%E' is not constant", result);
1086         }
1087
1088         return result;
1089 }
1090
1091 static expression_t *parse_assignment_expression(void)
1092 {
1093         return parse_subexpression(PREC_ASSIGNMENT);
1094 }
1095
1096 static void warn_string_concat(const source_position_t *pos)
1097 {
1098         if (warning.traditional) {
1099                 warningf(pos, "traditional C rejects string constant concatenation");
1100         }
1101 }
1102
1103 static string_t parse_string_literals(void)
1104 {
1105         assert(token.type == T_STRING_LITERAL);
1106         string_t result = token.literal;
1107
1108         next_token();
1109
1110         while (token.type == T_STRING_LITERAL) {
1111                 warn_string_concat(&token.source_position);
1112                 result = concat_strings(&result, &token.literal);
1113                 next_token();
1114         }
1115
1116         return result;
1117 }
1118
1119 /**
1120  * compare two string, ignoring double underscores on the second.
1121  */
1122 static int strcmp_underscore(const char *s1, const char *s2)
1123 {
1124         if (s2[0] == '_' && s2[1] == '_') {
1125                 size_t len2 = strlen(s2);
1126                 size_t len1 = strlen(s1);
1127                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1128                         return strncmp(s1, s2+2, len2-4);
1129                 }
1130         }
1131
1132         return strcmp(s1, s2);
1133 }
1134
1135 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1136 {
1137         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1138         attribute->kind        = kind;
1139         return attribute;
1140 }
1141
1142 /**
1143  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1144  *
1145  *  attribute:
1146  *    __attribute__ ( ( attribute-list ) )
1147  *
1148  *  attribute-list:
1149  *    attrib
1150  *    attribute_list , attrib
1151  *
1152  *  attrib:
1153  *    empty
1154  *    any-word
1155  *    any-word ( identifier )
1156  *    any-word ( identifier , nonempty-expr-list )
1157  *    any-word ( expr-list )
1158  *
1159  *  where the "identifier" must not be declared as a type, and
1160  *  "any-word" may be any identifier (including one declared as a
1161  *  type), a reserved word storage class specifier, type specifier or
1162  *  type qualifier.  ??? This still leaves out most reserved keywords
1163  *  (following the old parser), shouldn't we include them, and why not
1164  *  allow identifiers declared as types to start the arguments?
1165  *
1166  *  Matze: this all looks confusing and little systematic, so we're even less
1167  *  strict and parse any list of things which are identifiers or
1168  *  (assignment-)expressions.
1169  */
1170 static attribute_argument_t *parse_attribute_arguments(void)
1171 {
1172         attribute_argument_t  *first  = NULL;
1173         attribute_argument_t **anchor = &first;
1174         if (token.type != ')') do {
1175                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1176
1177                 /* is it an identifier */
1178                 if (token.type == T_IDENTIFIER
1179                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1180                         symbol_t *symbol   = token.symbol;
1181                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1182                         argument->v.symbol = symbol;
1183                         next_token();
1184                 } else {
1185                         /* must be an expression */
1186                         expression_t *expression = parse_assignment_expression();
1187
1188                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1189                         argument->v.expression = expression;
1190                 }
1191
1192                 /* append argument */
1193                 *anchor = argument;
1194                 anchor  = &argument->next;
1195         } while (next_if(','));
1196         expect(')', end_error);
1197
1198         return first;
1199
1200 end_error:
1201         /* TODO... */
1202         return first;
1203 }
1204
1205 static attribute_t *parse_attribute_asm(void)
1206 {
1207         eat(T_asm);
1208
1209         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1210
1211         expect('(', end_error);
1212         attribute->a.arguments = parse_attribute_arguments();
1213         return attribute;
1214
1215 end_error:
1216         return NULL;
1217 }
1218
1219 static symbol_t *get_symbol_from_token(void)
1220 {
1221         switch(token.type) {
1222         case T_IDENTIFIER:
1223                 return token.symbol;
1224         case T_auto:
1225         case T_char:
1226         case T_double:
1227         case T_enum:
1228         case T_extern:
1229         case T_float:
1230         case T_int:
1231         case T_long:
1232         case T_register:
1233         case T_short:
1234         case T_static:
1235         case T_struct:
1236         case T_union:
1237         case T_unsigned:
1238         case T_void:
1239         case T_bool:
1240         case T__Bool:
1241         case T_class:
1242         case T_explicit:
1243         case T_export:
1244         case T_wchar_t:
1245         case T_const:
1246         case T_signed:
1247         case T___real__:
1248         case T___imag__:
1249         case T_restrict:
1250         case T_volatile:
1251         case T_inline:
1252                 /* maybe we need more tokens ... add them on demand */
1253                 return get_token_symbol(&token);
1254         default:
1255                 return NULL;
1256         }
1257 }
1258
1259 static attribute_t *parse_attribute_gnu_single(void)
1260 {
1261         /* parse "any-word" */
1262         symbol_t *symbol = get_symbol_from_token();
1263         if (symbol == NULL) {
1264                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1265                 return NULL;
1266         }
1267
1268         attribute_kind_t  kind;
1269         char const *const name = symbol->string;
1270         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1271                 if (kind > ATTRIBUTE_GNU_LAST) {
1272                         if (warning.attribute) {
1273                                 warningf(HERE, "unknown attribute '%s' ignored", name);
1274                         }
1275                         /* TODO: we should still save the attribute in the list... */
1276                         kind = ATTRIBUTE_UNKNOWN;
1277                         break;
1278                 }
1279
1280                 const char *attribute_name = get_attribute_name(kind);
1281                 if (attribute_name != NULL
1282                                 && strcmp_underscore(attribute_name, name) == 0)
1283                         break;
1284         }
1285
1286         next_token();
1287
1288         attribute_t *attribute = allocate_attribute_zero(kind);
1289
1290         /* parse arguments */
1291         if (next_if('('))
1292                 attribute->a.arguments = parse_attribute_arguments();
1293
1294         return attribute;
1295 }
1296
1297 static attribute_t *parse_attribute_gnu(void)
1298 {
1299         attribute_t  *first  = NULL;
1300         attribute_t **anchor = &first;
1301
1302         eat(T___attribute__);
1303         expect('(', end_error);
1304         expect('(', end_error);
1305
1306         if (token.type != ')') do {
1307                 attribute_t *attribute = parse_attribute_gnu_single();
1308                 if (attribute == NULL)
1309                         goto end_error;
1310
1311                 *anchor = attribute;
1312                 anchor  = &attribute->next;
1313         } while (next_if(','));
1314         expect(')', end_error);
1315         expect(')', end_error);
1316
1317 end_error:
1318         return first;
1319 }
1320
1321 /** Parse attributes. */
1322 static attribute_t *parse_attributes(attribute_t *first)
1323 {
1324         attribute_t **anchor = &first;
1325         for (;;) {
1326                 while (*anchor != NULL)
1327                         anchor = &(*anchor)->next;
1328
1329                 attribute_t *attribute;
1330                 switch (token.type) {
1331                 case T___attribute__:
1332                         attribute = parse_attribute_gnu();
1333                         if (attribute == NULL)
1334                                 continue;
1335                         break;
1336
1337                 case T_asm:
1338                         attribute = parse_attribute_asm();
1339                         break;
1340
1341                 case T_cdecl:
1342                         next_token();
1343                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1344                         break;
1345
1346                 case T__fastcall:
1347                         next_token();
1348                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1349                         break;
1350
1351                 case T__forceinline:
1352                         next_token();
1353                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1354                         break;
1355
1356                 case T__stdcall:
1357                         next_token();
1358                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1359                         break;
1360
1361                 case T___thiscall:
1362                         /* TODO record modifier */
1363                         if (warning.other)
1364                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1365                         eat(T___thiscall);
1366                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1367                         break;
1368
1369                 default:
1370                         return first;
1371                 }
1372
1373                 *anchor = attribute;
1374                 anchor  = &attribute->next;
1375         }
1376 }
1377
1378 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1379
1380 static entity_t *determine_lhs_ent(expression_t *const expr,
1381                                    entity_t *lhs_ent)
1382 {
1383         switch (expr->kind) {
1384                 case EXPR_REFERENCE: {
1385                         entity_t *const entity = expr->reference.entity;
1386                         /* we should only find variables as lvalues... */
1387                         if (entity->base.kind != ENTITY_VARIABLE
1388                                         && entity->base.kind != ENTITY_PARAMETER)
1389                                 return NULL;
1390
1391                         return entity;
1392                 }
1393
1394                 case EXPR_ARRAY_ACCESS: {
1395                         expression_t *const ref = expr->array_access.array_ref;
1396                         entity_t     *      ent = NULL;
1397                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1398                                 ent     = determine_lhs_ent(ref, lhs_ent);
1399                                 lhs_ent = ent;
1400                         } else {
1401                                 mark_vars_read(expr->select.compound, lhs_ent);
1402                         }
1403                         mark_vars_read(expr->array_access.index, lhs_ent);
1404                         return ent;
1405                 }
1406
1407                 case EXPR_SELECT: {
1408                         if (is_type_compound(skip_typeref(expr->base.type))) {
1409                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1410                         } else {
1411                                 mark_vars_read(expr->select.compound, lhs_ent);
1412                                 return NULL;
1413                         }
1414                 }
1415
1416                 case EXPR_UNARY_DEREFERENCE: {
1417                         expression_t *const val = expr->unary.value;
1418                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1419                                 /* *&x is a NOP */
1420                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1421                         } else {
1422                                 mark_vars_read(val, NULL);
1423                                 return NULL;
1424                         }
1425                 }
1426
1427                 default:
1428                         mark_vars_read(expr, NULL);
1429                         return NULL;
1430         }
1431 }
1432
1433 #define ENT_ANY ((entity_t*)-1)
1434
1435 /**
1436  * Mark declarations, which are read.  This is used to detect variables, which
1437  * are never read.
1438  * Example:
1439  * x = x + 1;
1440  *   x is not marked as "read", because it is only read to calculate its own new
1441  *   value.
1442  *
1443  * x += y; y += x;
1444  *   x and y are not detected as "not read", because multiple variables are
1445  *   involved.
1446  */
1447 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1448 {
1449         switch (expr->kind) {
1450                 case EXPR_REFERENCE: {
1451                         entity_t *const entity = expr->reference.entity;
1452                         if (entity->kind != ENTITY_VARIABLE
1453                                         && entity->kind != ENTITY_PARAMETER)
1454                                 return;
1455
1456                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1457                                 if (entity->kind == ENTITY_VARIABLE) {
1458                                         entity->variable.read = true;
1459                                 } else {
1460                                         entity->parameter.read = true;
1461                                 }
1462                         }
1463                         return;
1464                 }
1465
1466                 case EXPR_CALL:
1467                         // TODO respect pure/const
1468                         mark_vars_read(expr->call.function, NULL);
1469                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1470                                 mark_vars_read(arg->expression, NULL);
1471                         }
1472                         return;
1473
1474                 case EXPR_CONDITIONAL:
1475                         // TODO lhs_decl should depend on whether true/false have an effect
1476                         mark_vars_read(expr->conditional.condition, NULL);
1477                         if (expr->conditional.true_expression != NULL)
1478                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1479                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1480                         return;
1481
1482                 case EXPR_SELECT:
1483                         if (lhs_ent == ENT_ANY
1484                                         && !is_type_compound(skip_typeref(expr->base.type)))
1485                                 lhs_ent = NULL;
1486                         mark_vars_read(expr->select.compound, lhs_ent);
1487                         return;
1488
1489                 case EXPR_ARRAY_ACCESS: {
1490                         expression_t *const ref = expr->array_access.array_ref;
1491                         mark_vars_read(ref, lhs_ent);
1492                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1493                         mark_vars_read(expr->array_access.index, lhs_ent);
1494                         return;
1495                 }
1496
1497                 case EXPR_VA_ARG:
1498                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1499                         return;
1500
1501                 case EXPR_VA_COPY:
1502                         mark_vars_read(expr->va_copye.src, lhs_ent);
1503                         return;
1504
1505                 case EXPR_UNARY_CAST:
1506                         /* Special case: Use void cast to mark a variable as "read" */
1507                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1508                                 lhs_ent = NULL;
1509                         goto unary;
1510
1511
1512                 case EXPR_UNARY_THROW:
1513                         if (expr->unary.value == NULL)
1514                                 return;
1515                         /* FALLTHROUGH */
1516                 case EXPR_UNARY_DEREFERENCE:
1517                 case EXPR_UNARY_DELETE:
1518                 case EXPR_UNARY_DELETE_ARRAY:
1519                         if (lhs_ent == ENT_ANY)
1520                                 lhs_ent = NULL;
1521                         goto unary;
1522
1523                 case EXPR_UNARY_NEGATE:
1524                 case EXPR_UNARY_PLUS:
1525                 case EXPR_UNARY_BITWISE_NEGATE:
1526                 case EXPR_UNARY_NOT:
1527                 case EXPR_UNARY_TAKE_ADDRESS:
1528                 case EXPR_UNARY_POSTFIX_INCREMENT:
1529                 case EXPR_UNARY_POSTFIX_DECREMENT:
1530                 case EXPR_UNARY_PREFIX_INCREMENT:
1531                 case EXPR_UNARY_PREFIX_DECREMENT:
1532                 case EXPR_UNARY_CAST_IMPLICIT:
1533                 case EXPR_UNARY_ASSUME:
1534 unary:
1535                         mark_vars_read(expr->unary.value, lhs_ent);
1536                         return;
1537
1538                 case EXPR_BINARY_ADD:
1539                 case EXPR_BINARY_SUB:
1540                 case EXPR_BINARY_MUL:
1541                 case EXPR_BINARY_DIV:
1542                 case EXPR_BINARY_MOD:
1543                 case EXPR_BINARY_EQUAL:
1544                 case EXPR_BINARY_NOTEQUAL:
1545                 case EXPR_BINARY_LESS:
1546                 case EXPR_BINARY_LESSEQUAL:
1547                 case EXPR_BINARY_GREATER:
1548                 case EXPR_BINARY_GREATEREQUAL:
1549                 case EXPR_BINARY_BITWISE_AND:
1550                 case EXPR_BINARY_BITWISE_OR:
1551                 case EXPR_BINARY_BITWISE_XOR:
1552                 case EXPR_BINARY_LOGICAL_AND:
1553                 case EXPR_BINARY_LOGICAL_OR:
1554                 case EXPR_BINARY_SHIFTLEFT:
1555                 case EXPR_BINARY_SHIFTRIGHT:
1556                 case EXPR_BINARY_COMMA:
1557                 case EXPR_BINARY_ISGREATER:
1558                 case EXPR_BINARY_ISGREATEREQUAL:
1559                 case EXPR_BINARY_ISLESS:
1560                 case EXPR_BINARY_ISLESSEQUAL:
1561                 case EXPR_BINARY_ISLESSGREATER:
1562                 case EXPR_BINARY_ISUNORDERED:
1563                         mark_vars_read(expr->binary.left,  lhs_ent);
1564                         mark_vars_read(expr->binary.right, lhs_ent);
1565                         return;
1566
1567                 case EXPR_BINARY_ASSIGN:
1568                 case EXPR_BINARY_MUL_ASSIGN:
1569                 case EXPR_BINARY_DIV_ASSIGN:
1570                 case EXPR_BINARY_MOD_ASSIGN:
1571                 case EXPR_BINARY_ADD_ASSIGN:
1572                 case EXPR_BINARY_SUB_ASSIGN:
1573                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1574                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1575                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1576                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1577                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1578                         if (lhs_ent == ENT_ANY)
1579                                 lhs_ent = NULL;
1580                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1581                         mark_vars_read(expr->binary.right, lhs_ent);
1582                         return;
1583                 }
1584
1585                 case EXPR_VA_START:
1586                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1587                         return;
1588
1589                 EXPR_LITERAL_CASES
1590                 case EXPR_UNKNOWN:
1591                 case EXPR_INVALID:
1592                 case EXPR_STRING_LITERAL:
1593                 case EXPR_WIDE_STRING_LITERAL:
1594                 case EXPR_COMPOUND_LITERAL: // TODO init?
1595                 case EXPR_SIZEOF:
1596                 case EXPR_CLASSIFY_TYPE:
1597                 case EXPR_ALIGNOF:
1598                 case EXPR_FUNCNAME:
1599                 case EXPR_BUILTIN_CONSTANT_P:
1600                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1601                 case EXPR_OFFSETOF:
1602                 case EXPR_STATEMENT: // TODO
1603                 case EXPR_LABEL_ADDRESS:
1604                 case EXPR_REFERENCE_ENUM_VALUE:
1605                         return;
1606         }
1607
1608         panic("unhandled expression");
1609 }
1610
1611 static designator_t *parse_designation(void)
1612 {
1613         designator_t  *result = NULL;
1614         designator_t **anchor = &result;
1615
1616         for (;;) {
1617                 designator_t *designator;
1618                 switch (token.type) {
1619                 case '[':
1620                         designator = allocate_ast_zero(sizeof(designator[0]));
1621                         designator->source_position = token.source_position;
1622                         next_token();
1623                         add_anchor_token(']');
1624                         designator->array_index = parse_constant_expression();
1625                         rem_anchor_token(']');
1626                         expect(']', end_error);
1627                         break;
1628                 case '.':
1629                         designator = allocate_ast_zero(sizeof(designator[0]));
1630                         designator->source_position = token.source_position;
1631                         next_token();
1632                         if (token.type != T_IDENTIFIER) {
1633                                 parse_error_expected("while parsing designator",
1634                                                      T_IDENTIFIER, NULL);
1635                                 return NULL;
1636                         }
1637                         designator->symbol = token.symbol;
1638                         next_token();
1639                         break;
1640                 default:
1641                         expect('=', end_error);
1642                         return result;
1643                 }
1644
1645                 assert(designator != NULL);
1646                 *anchor = designator;
1647                 anchor  = &designator->next;
1648         }
1649 end_error:
1650         return NULL;
1651 }
1652
1653 static initializer_t *initializer_from_string(array_type_t *const type,
1654                                               const string_t *const string)
1655 {
1656         /* TODO: check len vs. size of array type */
1657         (void) type;
1658
1659         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1660         initializer->string.string = *string;
1661
1662         return initializer;
1663 }
1664
1665 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1666                                                    const string_t *const string)
1667 {
1668         /* TODO: check len vs. size of array type */
1669         (void) type;
1670
1671         initializer_t *const initializer =
1672                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1673         initializer->wide_string.string = *string;
1674
1675         return initializer;
1676 }
1677
1678 /**
1679  * Build an initializer from a given expression.
1680  */
1681 static initializer_t *initializer_from_expression(type_t *orig_type,
1682                                                   expression_t *expression)
1683 {
1684         /* TODO check that expression is a constant expression */
1685
1686         /* §6.7.8.14/15 char array may be initialized by string literals */
1687         type_t *type           = skip_typeref(orig_type);
1688         type_t *expr_type_orig = expression->base.type;
1689         type_t *expr_type      = skip_typeref(expr_type_orig);
1690
1691         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1692                 array_type_t *const array_type   = &type->array;
1693                 type_t       *const element_type = skip_typeref(array_type->element_type);
1694
1695                 if (element_type->kind == TYPE_ATOMIC) {
1696                         atomic_type_kind_t akind = element_type->atomic.akind;
1697                         switch (expression->kind) {
1698                         case EXPR_STRING_LITERAL:
1699                                 if (akind == ATOMIC_TYPE_CHAR
1700                                                 || akind == ATOMIC_TYPE_SCHAR
1701                                                 || akind == ATOMIC_TYPE_UCHAR) {
1702                                         return initializer_from_string(array_type,
1703                                                         &expression->string_literal.value);
1704                                 }
1705                                 break;
1706
1707                         case EXPR_WIDE_STRING_LITERAL: {
1708                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1709                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1710                                         return initializer_from_wide_string(array_type,
1711                                                         &expression->string_literal.value);
1712                                 }
1713                                 break;
1714                         }
1715
1716                         default:
1717                                 break;
1718                         }
1719                 }
1720         }
1721
1722         assign_error_t error = semantic_assign(type, expression);
1723         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1724                 return NULL;
1725         report_assign_error(error, type, expression, "initializer",
1726                             &expression->base.source_position);
1727
1728         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1729         result->value.value = create_implicit_cast(expression, type);
1730
1731         return result;
1732 }
1733
1734 /**
1735  * Checks if a given expression can be used as a constant initializer.
1736  */
1737 static bool is_initializer_constant(const expression_t *expression)
1738 {
1739         return is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
1740                is_linker_constant(expression)     != EXPR_CLASS_VARIABLE;
1741 }
1742
1743 /**
1744  * Parses an scalar initializer.
1745  *
1746  * §6.7.8.11; eat {} without warning
1747  */
1748 static initializer_t *parse_scalar_initializer(type_t *type,
1749                                                bool must_be_constant)
1750 {
1751         /* there might be extra {} hierarchies */
1752         int braces = 0;
1753         if (token.type == '{') {
1754                 if (warning.other)
1755                         warningf(HERE, "extra curly braces around scalar initializer");
1756                 do {
1757                         eat('{');
1758                         ++braces;
1759                 } while (token.type == '{');
1760         }
1761
1762         expression_t *expression = parse_assignment_expression();
1763         mark_vars_read(expression, NULL);
1764         if (must_be_constant && !is_initializer_constant(expression)) {
1765                 errorf(&expression->base.source_position,
1766                        "initialisation expression '%E' is not constant",
1767                        expression);
1768         }
1769
1770         initializer_t *initializer = initializer_from_expression(type, expression);
1771
1772         if (initializer == NULL) {
1773                 errorf(&expression->base.source_position,
1774                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1775                        expression, expression->base.type, type);
1776                 /* TODO */
1777                 return NULL;
1778         }
1779
1780         bool additional_warning_displayed = false;
1781         while (braces > 0) {
1782                 next_if(',');
1783                 if (token.type != '}') {
1784                         if (!additional_warning_displayed && warning.other) {
1785                                 warningf(HERE, "additional elements in scalar initializer");
1786                                 additional_warning_displayed = true;
1787                         }
1788                 }
1789                 eat_block();
1790                 braces--;
1791         }
1792
1793         return initializer;
1794 }
1795
1796 /**
1797  * An entry in the type path.
1798  */
1799 typedef struct type_path_entry_t type_path_entry_t;
1800 struct type_path_entry_t {
1801         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1802         union {
1803                 size_t         index;          /**< For array types: the current index. */
1804                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1805         } v;
1806 };
1807
1808 /**
1809  * A type path expression a position inside compound or array types.
1810  */
1811 typedef struct type_path_t type_path_t;
1812 struct type_path_t {
1813         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1814         type_t            *top_type;     /**< type of the element the path points */
1815         size_t             max_index;    /**< largest index in outermost array */
1816 };
1817
1818 /**
1819  * Prints a type path for debugging.
1820  */
1821 static __attribute__((unused)) void debug_print_type_path(
1822                 const type_path_t *path)
1823 {
1824         size_t len = ARR_LEN(path->path);
1825
1826         for (size_t i = 0; i < len; ++i) {
1827                 const type_path_entry_t *entry = & path->path[i];
1828
1829                 type_t *type = skip_typeref(entry->type);
1830                 if (is_type_compound(type)) {
1831                         /* in gcc mode structs can have no members */
1832                         if (entry->v.compound_entry == NULL) {
1833                                 assert(i == len-1);
1834                                 continue;
1835                         }
1836                         fprintf(stderr, ".%s",
1837                                 entry->v.compound_entry->base.symbol->string);
1838                 } else if (is_type_array(type)) {
1839                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1840                 } else {
1841                         fprintf(stderr, "-INVALID-");
1842                 }
1843         }
1844         if (path->top_type != NULL) {
1845                 fprintf(stderr, "  (");
1846                 print_type(path->top_type);
1847                 fprintf(stderr, ")");
1848         }
1849 }
1850
1851 /**
1852  * Return the top type path entry, ie. in a path
1853  * (type).a.b returns the b.
1854  */
1855 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1856 {
1857         size_t len = ARR_LEN(path->path);
1858         assert(len > 0);
1859         return &path->path[len-1];
1860 }
1861
1862 /**
1863  * Enlarge the type path by an (empty) element.
1864  */
1865 static type_path_entry_t *append_to_type_path(type_path_t *path)
1866 {
1867         size_t len = ARR_LEN(path->path);
1868         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1869
1870         type_path_entry_t *result = & path->path[len];
1871         memset(result, 0, sizeof(result[0]));
1872         return result;
1873 }
1874
1875 /**
1876  * Descending into a sub-type. Enter the scope of the current top_type.
1877  */
1878 static void descend_into_subtype(type_path_t *path)
1879 {
1880         type_t *orig_top_type = path->top_type;
1881         type_t *top_type      = skip_typeref(orig_top_type);
1882
1883         type_path_entry_t *top = append_to_type_path(path);
1884         top->type              = top_type;
1885
1886         if (is_type_compound(top_type)) {
1887                 compound_t *compound  = top_type->compound.compound;
1888                 entity_t   *entry     = compound->members.entities;
1889
1890                 if (entry != NULL) {
1891                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
1892                         top->v.compound_entry = &entry->declaration;
1893                         path->top_type = entry->declaration.type;
1894                 } else {
1895                         path->top_type = NULL;
1896                 }
1897         } else if (is_type_array(top_type)) {
1898                 top->v.index   = 0;
1899                 path->top_type = top_type->array.element_type;
1900         } else {
1901                 assert(!is_type_valid(top_type));
1902         }
1903 }
1904
1905 /**
1906  * Pop an entry from the given type path, ie. returning from
1907  * (type).a.b to (type).a
1908  */
1909 static void ascend_from_subtype(type_path_t *path)
1910 {
1911         type_path_entry_t *top = get_type_path_top(path);
1912
1913         path->top_type = top->type;
1914
1915         size_t len = ARR_LEN(path->path);
1916         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1917 }
1918
1919 /**
1920  * Pop entries from the given type path until the given
1921  * path level is reached.
1922  */
1923 static void ascend_to(type_path_t *path, size_t top_path_level)
1924 {
1925         size_t len = ARR_LEN(path->path);
1926
1927         while (len > top_path_level) {
1928                 ascend_from_subtype(path);
1929                 len = ARR_LEN(path->path);
1930         }
1931 }
1932
1933 static bool walk_designator(type_path_t *path, const designator_t *designator,
1934                             bool used_in_offsetof)
1935 {
1936         for (; designator != NULL; designator = designator->next) {
1937                 type_path_entry_t *top       = get_type_path_top(path);
1938                 type_t            *orig_type = top->type;
1939
1940                 type_t *type = skip_typeref(orig_type);
1941
1942                 if (designator->symbol != NULL) {
1943                         symbol_t *symbol = designator->symbol;
1944                         if (!is_type_compound(type)) {
1945                                 if (is_type_valid(type)) {
1946                                         errorf(&designator->source_position,
1947                                                "'.%Y' designator used for non-compound type '%T'",
1948                                                symbol, orig_type);
1949                                 }
1950
1951                                 top->type             = type_error_type;
1952                                 top->v.compound_entry = NULL;
1953                                 orig_type             = type_error_type;
1954                         } else {
1955                                 compound_t *compound = type->compound.compound;
1956                                 entity_t   *iter     = compound->members.entities;
1957                                 for (; iter != NULL; iter = iter->base.next) {
1958                                         if (iter->base.symbol == symbol) {
1959                                                 break;
1960                                         }
1961                                 }
1962                                 if (iter == NULL) {
1963                                         errorf(&designator->source_position,
1964                                                "'%T' has no member named '%Y'", orig_type, symbol);
1965                                         return false;
1966                                 }
1967                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1968                                 if (used_in_offsetof) {
1969                                         type_t *real_type = skip_typeref(iter->declaration.type);
1970                                         if (real_type->kind == TYPE_BITFIELD) {
1971                                                 errorf(&designator->source_position,
1972                                                        "offsetof designator '%Y' must not specify bitfield",
1973                                                        symbol);
1974                                                 return false;
1975                                         }
1976                                 }
1977
1978                                 top->type             = orig_type;
1979                                 top->v.compound_entry = &iter->declaration;
1980                                 orig_type             = iter->declaration.type;
1981                         }
1982                 } else {
1983                         expression_t *array_index = designator->array_index;
1984                         assert(designator->array_index != NULL);
1985
1986                         if (!is_type_array(type)) {
1987                                 if (is_type_valid(type)) {
1988                                         errorf(&designator->source_position,
1989                                                "[%E] designator used for non-array type '%T'",
1990                                                array_index, orig_type);
1991                                 }
1992                                 return false;
1993                         }
1994
1995                         long index = fold_constant_to_int(array_index);
1996                         if (!used_in_offsetof) {
1997                                 if (index < 0) {
1998                                         errorf(&designator->source_position,
1999                                                "array index [%E] must be positive", array_index);
2000                                 } else if (type->array.size_constant) {
2001                                         long array_size = type->array.size;
2002                                         if (index >= array_size) {
2003                                                 errorf(&designator->source_position,
2004                                                        "designator [%E] (%d) exceeds array size %d",
2005                                                        array_index, index, array_size);
2006                                         }
2007                                 }
2008                         }
2009
2010                         top->type    = orig_type;
2011                         top->v.index = (size_t) index;
2012                         orig_type    = type->array.element_type;
2013                 }
2014                 path->top_type = orig_type;
2015
2016                 if (designator->next != NULL) {
2017                         descend_into_subtype(path);
2018                 }
2019         }
2020         return true;
2021 }
2022
2023 static void advance_current_object(type_path_t *path, size_t top_path_level)
2024 {
2025         type_path_entry_t *top = get_type_path_top(path);
2026
2027         type_t *type = skip_typeref(top->type);
2028         if (is_type_union(type)) {
2029                 /* in unions only the first element is initialized */
2030                 top->v.compound_entry = NULL;
2031         } else if (is_type_struct(type)) {
2032                 declaration_t *entry = top->v.compound_entry;
2033
2034                 entity_t *next_entity = entry->base.next;
2035                 if (next_entity != NULL) {
2036                         assert(is_declaration(next_entity));
2037                         entry = &next_entity->declaration;
2038                 } else {
2039                         entry = NULL;
2040                 }
2041
2042                 top->v.compound_entry = entry;
2043                 if (entry != NULL) {
2044                         path->top_type = entry->type;
2045                         return;
2046                 }
2047         } else if (is_type_array(type)) {
2048                 assert(is_type_array(type));
2049
2050                 top->v.index++;
2051
2052                 if (!type->array.size_constant || top->v.index < type->array.size) {
2053                         return;
2054                 }
2055         } else {
2056                 assert(!is_type_valid(type));
2057                 return;
2058         }
2059
2060         /* we're past the last member of the current sub-aggregate, try if we
2061          * can ascend in the type hierarchy and continue with another subobject */
2062         size_t len = ARR_LEN(path->path);
2063
2064         if (len > top_path_level) {
2065                 ascend_from_subtype(path);
2066                 advance_current_object(path, top_path_level);
2067         } else {
2068                 path->top_type = NULL;
2069         }
2070 }
2071
2072 /**
2073  * skip any {...} blocks until a closing bracket is reached.
2074  */
2075 static void skip_initializers(void)
2076 {
2077         next_if('{');
2078
2079         while (token.type != '}') {
2080                 if (token.type == T_EOF)
2081                         return;
2082                 if (token.type == '{') {
2083                         eat_block();
2084                         continue;
2085                 }
2086                 next_token();
2087         }
2088 }
2089
2090 static initializer_t *create_empty_initializer(void)
2091 {
2092         static initializer_t empty_initializer
2093                 = { .list = { { INITIALIZER_LIST }, 0 } };
2094         return &empty_initializer;
2095 }
2096
2097 /**
2098  * Parse a part of an initialiser for a struct or union,
2099  */
2100 static initializer_t *parse_sub_initializer(type_path_t *path,
2101                 type_t *outer_type, size_t top_path_level,
2102                 parse_initializer_env_t *env)
2103 {
2104         if (token.type == '}') {
2105                 /* empty initializer */
2106                 return create_empty_initializer();
2107         }
2108
2109         type_t *orig_type = path->top_type;
2110         type_t *type      = NULL;
2111
2112         if (orig_type == NULL) {
2113                 /* We are initializing an empty compound. */
2114         } else {
2115                 type = skip_typeref(orig_type);
2116         }
2117
2118         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2119
2120         while (true) {
2121                 designator_t *designator = NULL;
2122                 if (token.type == '.' || token.type == '[') {
2123                         designator = parse_designation();
2124                         goto finish_designator;
2125                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2126                         /* GNU-style designator ("identifier: value") */
2127                         designator = allocate_ast_zero(sizeof(designator[0]));
2128                         designator->source_position = token.source_position;
2129                         designator->symbol          = token.symbol;
2130                         eat(T_IDENTIFIER);
2131                         eat(':');
2132
2133 finish_designator:
2134                         /* reset path to toplevel, evaluate designator from there */
2135                         ascend_to(path, top_path_level);
2136                         if (!walk_designator(path, designator, false)) {
2137                                 /* can't continue after designation error */
2138                                 goto end_error;
2139                         }
2140
2141                         initializer_t *designator_initializer
2142                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2143                         designator_initializer->designator.designator = designator;
2144                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2145
2146                         orig_type = path->top_type;
2147                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2148                 }
2149
2150                 initializer_t *sub;
2151
2152                 if (token.type == '{') {
2153                         if (type != NULL && is_type_scalar(type)) {
2154                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2155                         } else {
2156                                 if (type == NULL) {
2157                                         if (env->entity != NULL) {
2158                                                 errorf(HERE,
2159                                                      "extra brace group at end of initializer for '%Y'",
2160                                                      env->entity->base.symbol);
2161                                         } else {
2162                                                 errorf(HERE, "extra brace group at end of initializer");
2163                                         }
2164                                         eat('{');
2165                                 } else {
2166                                         eat('{');
2167                                         descend_into_subtype(path);
2168                                 }
2169
2170                                 add_anchor_token('}');
2171                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2172                                                             env);
2173                                 rem_anchor_token('}');
2174
2175                                 if (type != NULL) {
2176                                         ascend_from_subtype(path);
2177                                         expect('}', end_error);
2178                                 } else {
2179                                         expect('}', end_error);
2180                                         goto error_parse_next;
2181                                 }
2182                         }
2183                 } else {
2184                         /* must be an expression */
2185                         expression_t *expression = parse_assignment_expression();
2186                         mark_vars_read(expression, NULL);
2187
2188                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2189                                 errorf(&expression->base.source_position,
2190                                        "Initialisation expression '%E' is not constant",
2191                                        expression);
2192                         }
2193
2194                         if (type == NULL) {
2195                                 /* we are already outside, ... */
2196                                 if (outer_type == NULL)
2197                                         goto error_parse_next;
2198                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2199                                 if (is_type_compound(outer_type_skip) &&
2200                                                 !outer_type_skip->compound.compound->complete) {
2201                                         goto error_parse_next;
2202                                 }
2203
2204                                 if (warning.other) {
2205                                         source_position_t const* const pos = &expression->base.source_position;
2206                                         if (env->entity != NULL) {
2207                                                 warningf(pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2208                                         } else {
2209                                                 warningf(pos, "excess elements in initializer");
2210                                         }
2211                                 }
2212                                 goto error_parse_next;
2213                         }
2214
2215                         /* handle { "string" } special case */
2216                         if ((expression->kind == EXPR_STRING_LITERAL
2217                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2218                                         && outer_type != NULL) {
2219                                 sub = initializer_from_expression(outer_type, expression);
2220                                 if (sub != NULL) {
2221                                         next_if(',');
2222                                         if (token.type != '}' && warning.other) {
2223                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2224                                                                  orig_type);
2225                                         }
2226                                         /* TODO: eat , ... */
2227                                         return sub;
2228                                 }
2229                         }
2230
2231                         /* descend into subtypes until expression matches type */
2232                         while (true) {
2233                                 orig_type = path->top_type;
2234                                 type      = skip_typeref(orig_type);
2235
2236                                 sub = initializer_from_expression(orig_type, expression);
2237                                 if (sub != NULL) {
2238                                         break;
2239                                 }
2240                                 if (!is_type_valid(type)) {
2241                                         goto end_error;
2242                                 }
2243                                 if (is_type_scalar(type)) {
2244                                         errorf(&expression->base.source_position,
2245                                                         "expression '%E' doesn't match expected type '%T'",
2246                                                         expression, orig_type);
2247                                         goto end_error;
2248                                 }
2249
2250                                 descend_into_subtype(path);
2251                         }
2252                 }
2253
2254                 /* update largest index of top array */
2255                 const type_path_entry_t *first      = &path->path[0];
2256                 type_t                  *first_type = first->type;
2257                 first_type                          = skip_typeref(first_type);
2258                 if (is_type_array(first_type)) {
2259                         size_t index = first->v.index;
2260                         if (index > path->max_index)
2261                                 path->max_index = index;
2262                 }
2263
2264                 /* append to initializers list */
2265                 ARR_APP1(initializer_t*, initializers, sub);
2266
2267 error_parse_next:
2268                 if (token.type == '}') {
2269                         break;
2270                 }
2271                 expect(',', end_error);
2272                 if (token.type == '}') {
2273                         break;
2274                 }
2275
2276                 if (type != NULL) {
2277                         /* advance to the next declaration if we are not at the end */
2278                         advance_current_object(path, top_path_level);
2279                         orig_type = path->top_type;
2280                         if (orig_type != NULL)
2281                                 type = skip_typeref(orig_type);
2282                         else
2283                                 type = NULL;
2284                 }
2285         }
2286
2287         size_t len  = ARR_LEN(initializers);
2288         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2289         initializer_t *result = allocate_ast_zero(size);
2290         result->kind          = INITIALIZER_LIST;
2291         result->list.len      = len;
2292         memcpy(&result->list.initializers, initializers,
2293                len * sizeof(initializers[0]));
2294
2295         DEL_ARR_F(initializers);
2296         ascend_to(path, top_path_level+1);
2297
2298         return result;
2299
2300 end_error:
2301         skip_initializers();
2302         DEL_ARR_F(initializers);
2303         ascend_to(path, top_path_level+1);
2304         return NULL;
2305 }
2306
2307 static expression_t *make_size_literal(size_t value)
2308 {
2309         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2310         literal->base.type    = type_size_t;
2311
2312         char buf[128];
2313         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2314         literal->literal.value = make_string(buf);
2315
2316         return literal;
2317 }
2318
2319 /**
2320  * Parses an initializer. Parsers either a compound literal
2321  * (env->declaration == NULL) or an initializer of a declaration.
2322  */
2323 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2324 {
2325         type_t        *type      = skip_typeref(env->type);
2326         size_t         max_index = 0;
2327         initializer_t *result;
2328
2329         if (is_type_scalar(type)) {
2330                 result = parse_scalar_initializer(type, env->must_be_constant);
2331         } else if (token.type == '{') {
2332                 eat('{');
2333
2334                 type_path_t path;
2335                 memset(&path, 0, sizeof(path));
2336                 path.top_type = env->type;
2337                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2338
2339                 descend_into_subtype(&path);
2340
2341                 add_anchor_token('}');
2342                 result = parse_sub_initializer(&path, env->type, 1, env);
2343                 rem_anchor_token('}');
2344
2345                 max_index = path.max_index;
2346                 DEL_ARR_F(path.path);
2347
2348                 expect('}', end_error);
2349 end_error:;
2350         } else {
2351                 /* parse_scalar_initializer() also works in this case: we simply
2352                  * have an expression without {} around it */
2353                 result = parse_scalar_initializer(type, env->must_be_constant);
2354         }
2355
2356         /* §6.7.8:22 array initializers for arrays with unknown size determine
2357          * the array type size */
2358         if (is_type_array(type) && type->array.size_expression == NULL
2359                         && result != NULL) {
2360                 size_t size;
2361                 switch (result->kind) {
2362                 case INITIALIZER_LIST:
2363                         assert(max_index != 0xdeadbeaf);
2364                         size = max_index + 1;
2365                         break;
2366
2367                 case INITIALIZER_STRING:
2368                         size = result->string.string.size;
2369                         break;
2370
2371                 case INITIALIZER_WIDE_STRING:
2372                         size = result->wide_string.string.size;
2373                         break;
2374
2375                 case INITIALIZER_DESIGNATOR:
2376                 case INITIALIZER_VALUE:
2377                         /* can happen for parse errors */
2378                         size = 0;
2379                         break;
2380
2381                 default:
2382                         internal_errorf(HERE, "invalid initializer type");
2383                 }
2384
2385                 type_t *new_type = duplicate_type(type);
2386
2387                 new_type->array.size_expression   = make_size_literal(size);
2388                 new_type->array.size_constant     = true;
2389                 new_type->array.has_implicit_size = true;
2390                 new_type->array.size              = size;
2391                 env->type = new_type;
2392         }
2393
2394         return result;
2395 }
2396
2397 static void append_entity(scope_t *scope, entity_t *entity)
2398 {
2399         if (scope->last_entity != NULL) {
2400                 scope->last_entity->base.next = entity;
2401         } else {
2402                 scope->entities = entity;
2403         }
2404         entity->base.parent_entity = current_entity;
2405         scope->last_entity         = entity;
2406 }
2407
2408
2409 static compound_t *parse_compound_type_specifier(bool is_struct)
2410 {
2411         source_position_t const pos = *HERE;
2412         eat(is_struct ? T_struct : T_union);
2413
2414         symbol_t    *symbol     = NULL;
2415         entity_t    *entity     = NULL;
2416         attribute_t *attributes = NULL;
2417
2418         if (token.type == T___attribute__) {
2419                 attributes = parse_attributes(NULL);
2420         }
2421
2422         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2423         if (token.type == T_IDENTIFIER) {
2424                 /* the compound has a name, check if we have seen it already */
2425                 symbol = token.symbol;
2426                 entity = get_tag(symbol, kind);
2427                 next_token();
2428
2429                 if (entity != NULL) {
2430                         if (entity->base.parent_scope != current_scope &&
2431                             (token.type == '{' || token.type == ';')) {
2432                                 /* we're in an inner scope and have a definition. Shadow
2433                                  * existing definition in outer scope */
2434                                 entity = NULL;
2435                         } else if (entity->compound.complete && token.type == '{') {
2436                                 source_position_t const *const ppos = &entity->base.source_position;
2437                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2438                                 /* clear members in the hope to avoid further errors */
2439                                 entity->compound.members.entities = NULL;
2440                         }
2441                 }
2442         } else if (token.type != '{') {
2443                 char const *const msg =
2444                         is_struct ? "while parsing struct type specifier" :
2445                                     "while parsing union type specifier";
2446                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2447
2448                 return NULL;
2449         }
2450
2451         if (entity == NULL) {
2452                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol);
2453                 entity->compound.alignment   = 1;
2454                 entity->base.source_position = pos;
2455                 entity->base.parent_scope    = current_scope;
2456                 if (symbol != NULL) {
2457                         environment_push(entity);
2458                 }
2459                 append_entity(current_scope, entity);
2460         }
2461
2462         if (token.type == '{') {
2463                 parse_compound_type_entries(&entity->compound);
2464
2465                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2466                 if (symbol == NULL) {
2467                         assert(anonymous_entity == NULL);
2468                         anonymous_entity = entity;
2469                 }
2470         }
2471
2472         if (attributes != NULL) {
2473                 handle_entity_attributes(attributes, entity);
2474         }
2475
2476         return &entity->compound;
2477 }
2478
2479 static void parse_enum_entries(type_t *const enum_type)
2480 {
2481         eat('{');
2482
2483         if (token.type == '}') {
2484                 errorf(HERE, "empty enum not allowed");
2485                 next_token();
2486                 return;
2487         }
2488
2489         add_anchor_token('}');
2490         do {
2491                 if (token.type != T_IDENTIFIER) {
2492                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2493                         eat_block();
2494                         rem_anchor_token('}');
2495                         return;
2496                 }
2497
2498                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, token.symbol);
2499                 entity->enum_value.enum_type = enum_type;
2500                 entity->base.source_position = token.source_position;
2501                 next_token();
2502
2503                 if (next_if('=')) {
2504                         expression_t *value = parse_constant_expression();
2505
2506                         value = create_implicit_cast(value, enum_type);
2507                         entity->enum_value.value = value;
2508
2509                         /* TODO semantic */
2510                 }
2511
2512                 record_entity(entity, false);
2513         } while (next_if(',') && token.type != '}');
2514         rem_anchor_token('}');
2515
2516         expect('}', end_error);
2517
2518 end_error:
2519         ;
2520 }
2521
2522 static type_t *parse_enum_specifier(void)
2523 {
2524         source_position_t const pos = *HERE;
2525         entity_t               *entity;
2526         symbol_t               *symbol;
2527
2528         eat(T_enum);
2529         switch (token.type) {
2530                 case T_IDENTIFIER:
2531                         symbol = token.symbol;
2532                         entity = get_tag(symbol, ENTITY_ENUM);
2533                         next_token();
2534
2535                         if (entity != NULL) {
2536                                 if (entity->base.parent_scope != current_scope &&
2537                                                 (token.type == '{' || token.type == ';')) {
2538                                         /* we're in an inner scope and have a definition. Shadow
2539                                          * existing definition in outer scope */
2540                                         entity = NULL;
2541                                 } else if (entity->enume.complete && token.type == '{') {
2542                                         source_position_t const *const ppos = &entity->base.source_position;
2543                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2544                                 }
2545                         }
2546                         break;
2547
2548                 case '{':
2549                         entity = NULL;
2550                         symbol = NULL;
2551                         break;
2552
2553                 default:
2554                         parse_error_expected("while parsing enum type specifier",
2555                                         T_IDENTIFIER, '{', NULL);
2556                         return NULL;
2557         }
2558
2559         if (entity == NULL) {
2560                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol);
2561                 entity->base.source_position = pos;
2562                 entity->base.parent_scope    = current_scope;
2563         }
2564
2565         type_t *const type = allocate_type_zero(TYPE_ENUM);
2566         type->enumt.enume  = &entity->enume;
2567         type->enumt.akind  = ATOMIC_TYPE_INT;
2568
2569         if (token.type == '{') {
2570                 if (symbol != NULL) {
2571                         environment_push(entity);
2572                 }
2573                 append_entity(current_scope, entity);
2574                 entity->enume.complete = true;
2575
2576                 parse_enum_entries(type);
2577                 parse_attributes(NULL);
2578
2579                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2580                 if (symbol == NULL) {
2581                         assert(anonymous_entity == NULL);
2582                         anonymous_entity = entity;
2583                 }
2584         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2585                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2586         }
2587
2588         return type;
2589 }
2590
2591 /**
2592  * if a symbol is a typedef to another type, return true
2593  */
2594 static bool is_typedef_symbol(symbol_t *symbol)
2595 {
2596         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2597         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2598 }
2599
2600 static type_t *parse_typeof(void)
2601 {
2602         eat(T___typeof__);
2603
2604         type_t *type;
2605
2606         expect('(', end_error);
2607         add_anchor_token(')');
2608
2609         expression_t *expression  = NULL;
2610
2611         bool old_type_prop     = in_type_prop;
2612         bool old_gcc_extension = in_gcc_extension;
2613         in_type_prop           = true;
2614
2615         while (next_if(T___extension__)) {
2616                 /* This can be a prefix to a typename or an expression. */
2617                 in_gcc_extension = true;
2618         }
2619         switch (token.type) {
2620         case T_IDENTIFIER:
2621                 if (is_typedef_symbol(token.symbol)) {
2622         DECLARATION_START
2623                         type = parse_typename();
2624                 } else {
2625         default:
2626                         expression = parse_expression();
2627                         type       = revert_automatic_type_conversion(expression);
2628                 }
2629                 break;
2630         }
2631         in_type_prop     = old_type_prop;
2632         in_gcc_extension = old_gcc_extension;
2633
2634         rem_anchor_token(')');
2635         expect(')', end_error);
2636
2637         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2638         typeof_type->typeoft.expression  = expression;
2639         typeof_type->typeoft.typeof_type = type;
2640
2641         return typeof_type;
2642 end_error:
2643         return NULL;
2644 }
2645
2646 typedef enum specifiers_t {
2647         SPECIFIER_SIGNED    = 1 << 0,
2648         SPECIFIER_UNSIGNED  = 1 << 1,
2649         SPECIFIER_LONG      = 1 << 2,
2650         SPECIFIER_INT       = 1 << 3,
2651         SPECIFIER_DOUBLE    = 1 << 4,
2652         SPECIFIER_CHAR      = 1 << 5,
2653         SPECIFIER_WCHAR_T   = 1 << 6,
2654         SPECIFIER_SHORT     = 1 << 7,
2655         SPECIFIER_LONG_LONG = 1 << 8,
2656         SPECIFIER_FLOAT     = 1 << 9,
2657         SPECIFIER_BOOL      = 1 << 10,
2658         SPECIFIER_VOID      = 1 << 11,
2659         SPECIFIER_INT8      = 1 << 12,
2660         SPECIFIER_INT16     = 1 << 13,
2661         SPECIFIER_INT32     = 1 << 14,
2662         SPECIFIER_INT64     = 1 << 15,
2663         SPECIFIER_INT128    = 1 << 16,
2664         SPECIFIER_COMPLEX   = 1 << 17,
2665         SPECIFIER_IMAGINARY = 1 << 18,
2666 } specifiers_t;
2667
2668 static type_t *get_typedef_type(symbol_t *symbol)
2669 {
2670         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2671         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2672                 return NULL;
2673
2674         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2675         type->typedeft.typedefe = &entity->typedefe;
2676
2677         return type;
2678 }
2679
2680 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2681 {
2682         expect('(', end_error);
2683
2684         attribute_property_argument_t *property
2685                 = allocate_ast_zero(sizeof(*property));
2686
2687         do {
2688                 if (token.type != T_IDENTIFIER) {
2689                         parse_error_expected("while parsing property declspec",
2690                                              T_IDENTIFIER, NULL);
2691                         goto end_error;
2692                 }
2693
2694                 symbol_t **prop;
2695                 symbol_t  *symbol = token.symbol;
2696                 if (strcmp(symbol->string, "put") == 0) {
2697                         prop = &property->put_symbol;
2698                 } else if (strcmp(symbol->string, "get") == 0) {
2699                         prop = &property->get_symbol;
2700                 } else {
2701                         errorf(HERE, "expected put or get in property declspec");
2702                         prop = NULL;
2703                 }
2704                 eat(T_IDENTIFIER);
2705                 expect('=', end_error);
2706                 if (token.type != T_IDENTIFIER) {
2707                         parse_error_expected("while parsing property declspec",
2708                                              T_IDENTIFIER, NULL);
2709                         goto end_error;
2710                 }
2711                 if (prop != NULL)
2712                         *prop = token.symbol;
2713                 next_token();
2714         } while (next_if(','));
2715
2716         attribute->a.property = property;
2717
2718         expect(')', end_error);
2719
2720 end_error:
2721         return attribute;
2722 }
2723
2724 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2725 {
2726         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2727         if (next_if(T_restrict)) {
2728                 kind = ATTRIBUTE_MS_RESTRICT;
2729         } else if (token.type == T_IDENTIFIER) {
2730                 const char *name = token.symbol->string;
2731                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2732                      ++k) {
2733                         const char *attribute_name = get_attribute_name(k);
2734                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2735                                 kind = k;
2736                                 break;
2737                         }
2738                 }
2739
2740                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2741                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2742                 }
2743                 eat(T_IDENTIFIER);
2744         } else {
2745                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2746                 return NULL;
2747         }
2748
2749         attribute_t *attribute = allocate_attribute_zero(kind);
2750
2751         if (kind == ATTRIBUTE_MS_PROPERTY) {
2752                 return parse_attribute_ms_property(attribute);
2753         }
2754
2755         /* parse arguments */
2756         if (next_if('('))
2757                 attribute->a.arguments = parse_attribute_arguments();
2758
2759         return attribute;
2760 }
2761
2762 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2763 {
2764         eat(T__declspec);
2765
2766         expect('(', end_error);
2767
2768         if (next_if(')'))
2769                 return NULL;
2770
2771         add_anchor_token(')');
2772
2773         attribute_t **anchor = &first;
2774         do {
2775                 while (*anchor != NULL)
2776                         anchor = &(*anchor)->next;
2777
2778                 attribute_t *attribute
2779                         = parse_microsoft_extended_decl_modifier_single();
2780                 if (attribute == NULL)
2781                         goto end_error;
2782
2783                 *anchor = attribute;
2784                 anchor  = &attribute->next;
2785         } while (next_if(','));
2786
2787         rem_anchor_token(')');
2788         expect(')', end_error);
2789         return first;
2790
2791 end_error:
2792         rem_anchor_token(')');
2793         return first;
2794 }
2795
2796 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2797 {
2798         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol);
2799         entity->base.source_position = *HERE;
2800         if (is_declaration(entity)) {
2801                 entity->declaration.type     = type_error_type;
2802                 entity->declaration.implicit = true;
2803         } else if (kind == ENTITY_TYPEDEF) {
2804                 entity->typedefe.type    = type_error_type;
2805                 entity->typedefe.builtin = true;
2806         }
2807         if (kind != ENTITY_COMPOUND_MEMBER)
2808                 record_entity(entity, false);
2809         return entity;
2810 }
2811
2812 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2813 {
2814         type_t            *type              = NULL;
2815         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2816         unsigned           type_specifiers   = 0;
2817         bool               newtype           = false;
2818         bool               saw_error         = false;
2819         bool               old_gcc_extension = in_gcc_extension;
2820
2821         memset(specifiers, 0, sizeof(*specifiers));
2822         specifiers->source_position = token.source_position;
2823
2824         while (true) {
2825                 specifiers->attributes = parse_attributes(specifiers->attributes);
2826
2827                 switch (token.type) {
2828                 /* storage class */
2829 #define MATCH_STORAGE_CLASS(token, class)                                  \
2830                 case token:                                                        \
2831                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2832                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2833                         }                                                              \
2834                         specifiers->storage_class = class;                             \
2835                         if (specifiers->thread_local)                                  \
2836                                 goto check_thread_storage_class;                           \
2837                         next_token();                                                  \
2838                         break;
2839
2840                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2841                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2842                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2843                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2844                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2845
2846                 case T__declspec:
2847                         specifiers->attributes
2848                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2849                         break;
2850
2851                 case T___thread:
2852                         if (specifiers->thread_local) {
2853                                 errorf(HERE, "duplicate '__thread'");
2854                         } else {
2855                                 specifiers->thread_local = true;
2856 check_thread_storage_class:
2857                                 switch (specifiers->storage_class) {
2858                                         case STORAGE_CLASS_EXTERN:
2859                                         case STORAGE_CLASS_NONE:
2860                                         case STORAGE_CLASS_STATIC:
2861                                                 break;
2862
2863                                                 char const* wrong;
2864                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2865                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2866                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2867 wrong_thread_storage_class:
2868                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2869                                                 break;
2870                                 }
2871                         }
2872                         next_token();
2873                         break;
2874
2875                 /* type qualifiers */
2876 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2877                 case token:                                                     \
2878                         qualifiers |= qualifier;                                    \
2879                         next_token();                                               \
2880                         break
2881
2882                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2883                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2884                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2885                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2886                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2887                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2888                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2889                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2890
2891                 case T___extension__:
2892                         next_token();
2893                         in_gcc_extension = true;
2894                         break;
2895
2896                 /* type specifiers */
2897 #define MATCH_SPECIFIER(token, specifier, name)                         \
2898                 case token:                                                     \
2899                         if (type_specifiers & specifier) {                           \
2900                                 errorf(HERE, "multiple " name " type specifiers given"); \
2901                         } else {                                                    \
2902                                 type_specifiers |= specifier;                           \
2903                         }                                                           \
2904                         next_token();                                               \
2905                         break
2906
2907                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2908                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2909                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2910                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2911                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2912                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2913                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2914                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2915                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2916                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2917                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2918                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2919                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2920                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2921                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2922                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2923                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2924                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2925
2926                 case T_inline:
2927                         next_token();
2928                         specifiers->is_inline = true;
2929                         break;
2930
2931 #if 0
2932                 case T__forceinline:
2933                         next_token();
2934                         specifiers->modifiers |= DM_FORCEINLINE;
2935                         break;
2936 #endif
2937
2938                 case T_long:
2939                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2940                                 errorf(HERE, "too many long type specifiers given");
2941                         } else if (type_specifiers & SPECIFIER_LONG) {
2942                                 type_specifiers |= SPECIFIER_LONG_LONG;
2943                         } else {
2944                                 type_specifiers |= SPECIFIER_LONG;
2945                         }
2946                         next_token();
2947                         break;
2948
2949 #define CHECK_DOUBLE_TYPE()        \
2950                         do { \
2951                         if ( type != NULL)     \
2952                                 errorf(HERE, "multiple data types in declaration specifiers"); \
2953                         } while(0)
2954
2955                 case T_struct:
2956                         CHECK_DOUBLE_TYPE();
2957                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2958
2959                         type->compound.compound = parse_compound_type_specifier(true);
2960                         break;
2961                 case T_union:
2962                         CHECK_DOUBLE_TYPE();
2963                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2964                         type->compound.compound = parse_compound_type_specifier(false);
2965                         break;
2966                 case T_enum:
2967                         CHECK_DOUBLE_TYPE();
2968                         type = parse_enum_specifier();
2969                         break;
2970                 case T___typeof__:
2971                         CHECK_DOUBLE_TYPE();
2972                         type = parse_typeof();
2973                         break;
2974                 case T___builtin_va_list:
2975                         CHECK_DOUBLE_TYPE();
2976                         type = duplicate_type(type_valist);
2977                         next_token();
2978                         break;
2979
2980                 case T_IDENTIFIER: {
2981                         /* only parse identifier if we haven't found a type yet */
2982                         if (type != NULL || type_specifiers != 0) {
2983                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2984                                  * declaration, so it doesn't generate errors about expecting '(' or
2985                                  * '{' later on. */
2986                                 switch (look_ahead(1)->type) {
2987                                         STORAGE_CLASSES
2988                                         TYPE_SPECIFIERS
2989                                         case T_const:
2990                                         case T_restrict:
2991                                         case T_volatile:
2992                                         case T_inline:
2993                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2994                                         case T_IDENTIFIER:
2995                                         case '&':
2996                                         case '*':
2997                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2998                                                 next_token();
2999                                                 continue;
3000
3001                                         default:
3002                                                 goto finish_specifiers;
3003                                 }
3004                         }
3005
3006                         type_t *const typedef_type = get_typedef_type(token.symbol);
3007                         if (typedef_type == NULL) {
3008                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3009                                  * declaration, so it doesn't generate 'implicit int' followed by more
3010                                  * errors later on. */
3011                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3012                                 switch (la1_type) {
3013                                         DECLARATION_START
3014                                         case T_IDENTIFIER:
3015                                         case '&':
3016                                         case '*': {
3017                                                 errorf(HERE, "%K does not name a type", &token);
3018
3019                                                 entity_t *entity =
3020                                                         create_error_entity(token.symbol, ENTITY_TYPEDEF);
3021
3022                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3023                                                 type->typedeft.typedefe = &entity->typedefe;
3024
3025                                                 next_token();
3026                                                 saw_error = true;
3027                                                 continue;
3028                                         }
3029
3030                                         default:
3031                                                 goto finish_specifiers;
3032                                 }
3033                         }
3034
3035                         next_token();
3036                         type = typedef_type;
3037                         break;
3038                 }
3039
3040                 /* function specifier */
3041                 default:
3042                         goto finish_specifiers;
3043                 }
3044         }
3045
3046 finish_specifiers:
3047         specifiers->attributes = parse_attributes(specifiers->attributes);
3048
3049         in_gcc_extension = old_gcc_extension;
3050
3051         if (type == NULL || (saw_error && type_specifiers != 0)) {
3052                 atomic_type_kind_t atomic_type;
3053
3054                 /* match valid basic types */
3055                 switch (type_specifiers) {
3056                 case SPECIFIER_VOID:
3057                         atomic_type = ATOMIC_TYPE_VOID;
3058                         break;
3059                 case SPECIFIER_WCHAR_T:
3060                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3061                         break;
3062                 case SPECIFIER_CHAR:
3063                         atomic_type = ATOMIC_TYPE_CHAR;
3064                         break;
3065                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3066                         atomic_type = ATOMIC_TYPE_SCHAR;
3067                         break;
3068                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3069                         atomic_type = ATOMIC_TYPE_UCHAR;
3070                         break;
3071                 case SPECIFIER_SHORT:
3072                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3073                 case SPECIFIER_SHORT | SPECIFIER_INT:
3074                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3075                         atomic_type = ATOMIC_TYPE_SHORT;
3076                         break;
3077                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3078                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3079                         atomic_type = ATOMIC_TYPE_USHORT;
3080                         break;
3081                 case SPECIFIER_INT:
3082                 case SPECIFIER_SIGNED:
3083                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3084                         atomic_type = ATOMIC_TYPE_INT;
3085                         break;
3086                 case SPECIFIER_UNSIGNED:
3087                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3088                         atomic_type = ATOMIC_TYPE_UINT;
3089                         break;
3090                 case SPECIFIER_LONG:
3091                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3092                 case SPECIFIER_LONG | SPECIFIER_INT:
3093                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3094                         atomic_type = ATOMIC_TYPE_LONG;
3095                         break;
3096                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3097                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3098                         atomic_type = ATOMIC_TYPE_ULONG;
3099                         break;
3100
3101                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3102                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3103                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3104                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3105                         | SPECIFIER_INT:
3106                         atomic_type = ATOMIC_TYPE_LONGLONG;
3107                         goto warn_about_long_long;
3108
3109                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3110                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3111                         | SPECIFIER_INT:
3112                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3113 warn_about_long_long:
3114                         if (warning.long_long) {
3115                                 warningf(&specifiers->source_position,
3116                                          "ISO C90 does not support 'long long'");
3117                         }
3118                         break;
3119
3120                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3121                         atomic_type = unsigned_int8_type_kind;
3122                         break;
3123
3124                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3125                         atomic_type = unsigned_int16_type_kind;
3126                         break;
3127
3128                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3129                         atomic_type = unsigned_int32_type_kind;
3130                         break;
3131
3132                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3133                         atomic_type = unsigned_int64_type_kind;
3134                         break;
3135
3136                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3137                         atomic_type = unsigned_int128_type_kind;
3138                         break;
3139
3140                 case SPECIFIER_INT8:
3141                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3142                         atomic_type = int8_type_kind;
3143                         break;
3144
3145                 case SPECIFIER_INT16:
3146                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3147                         atomic_type = int16_type_kind;
3148                         break;
3149
3150                 case SPECIFIER_INT32:
3151                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3152                         atomic_type = int32_type_kind;
3153                         break;
3154
3155                 case SPECIFIER_INT64:
3156                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3157                         atomic_type = int64_type_kind;
3158                         break;
3159
3160                 case SPECIFIER_INT128:
3161                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3162                         atomic_type = int128_type_kind;
3163                         break;
3164
3165                 case SPECIFIER_FLOAT:
3166                         atomic_type = ATOMIC_TYPE_FLOAT;
3167                         break;
3168                 case SPECIFIER_DOUBLE:
3169                         atomic_type = ATOMIC_TYPE_DOUBLE;
3170                         break;
3171                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3172                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3173                         break;
3174                 case SPECIFIER_BOOL:
3175                         atomic_type = ATOMIC_TYPE_BOOL;
3176                         break;
3177                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3178                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3179                         atomic_type = ATOMIC_TYPE_FLOAT;
3180                         break;
3181                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3182                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3183                         atomic_type = ATOMIC_TYPE_DOUBLE;
3184                         break;
3185                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3186                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3187                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3188                         break;
3189                 default: {
3190                         /* invalid specifier combination, give an error message */
3191                         source_position_t const* const pos = &specifiers->source_position;
3192                         if (type_specifiers == 0) {
3193                                 if (!saw_error) {
3194                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3195                                         if (!(c_mode & _CXX) && !strict_mode) {
3196                                                 if (warning.implicit_int) {
3197                                                         warningf(pos, "no type specifiers in declaration, using 'int'");
3198                                                 }
3199                                                 atomic_type = ATOMIC_TYPE_INT;
3200                                                 break;
3201                                         } else {
3202                                                 errorf(pos, "no type specifiers given in declaration");
3203                                         }
3204                                 }
3205                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3206                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3207                                 errorf(pos, "signed and unsigned specifiers given");
3208                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3209                                 errorf(pos, "only integer types can be signed or unsigned");
3210                         } else {
3211                                 errorf(pos, "multiple datatypes in declaration");
3212                         }
3213                         goto end_error;
3214                 }
3215                 }
3216
3217                 if (type_specifiers & SPECIFIER_COMPLEX) {
3218                         type                = allocate_type_zero(TYPE_COMPLEX);
3219                         type->complex.akind = atomic_type;
3220                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3221                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3222                         type->imaginary.akind = atomic_type;
3223                 } else {
3224                         type                 = allocate_type_zero(TYPE_ATOMIC);
3225                         type->atomic.akind   = atomic_type;
3226                 }
3227                 newtype = true;
3228         } else if (type_specifiers != 0) {
3229                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3230         }
3231
3232         /* FIXME: check type qualifiers here */
3233         type->base.qualifiers = qualifiers;
3234
3235         if (newtype) {
3236                 type = identify_new_type(type);
3237         } else {
3238                 type = typehash_insert(type);
3239         }
3240
3241         if (specifiers->attributes != NULL)
3242                 type = handle_type_attributes(specifiers->attributes, type);
3243         specifiers->type = type;
3244         return;
3245
3246 end_error:
3247         specifiers->type = type_error_type;
3248 }
3249
3250 static type_qualifiers_t parse_type_qualifiers(void)
3251 {
3252         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3253
3254         while (true) {
3255                 switch (token.type) {
3256                 /* type qualifiers */
3257                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3258                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3259                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3260                 /* microsoft extended type modifiers */
3261                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3262                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3263                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3264                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3265                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3266
3267                 default:
3268                         return qualifiers;
3269                 }
3270         }
3271 }
3272
3273 /**
3274  * Parses an K&R identifier list
3275  */
3276 static void parse_identifier_list(scope_t *scope)
3277 {
3278         do {
3279                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.symbol);
3280                 entity->base.source_position = token.source_position;
3281                 /* a K&R parameter has no type, yet */
3282                 next_token();
3283
3284                 if (scope != NULL)
3285                         append_entity(scope, entity);
3286         } while (next_if(',') && token.type == T_IDENTIFIER);
3287 }
3288
3289 static entity_t *parse_parameter(void)
3290 {
3291         declaration_specifiers_t specifiers;
3292         parse_declaration_specifiers(&specifiers);
3293
3294         entity_t *entity = parse_declarator(&specifiers,
3295                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3296         anonymous_entity = NULL;
3297         return entity;
3298 }
3299
3300 static void semantic_parameter_incomplete(const entity_t *entity)
3301 {
3302         assert(entity->kind == ENTITY_PARAMETER);
3303
3304         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3305          *             list in a function declarator that is part of a
3306          *             definition of that function shall not have
3307          *             incomplete type. */
3308         type_t *type = skip_typeref(entity->declaration.type);
3309         if (is_type_incomplete(type)) {
3310                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3311         }
3312 }
3313
3314 static bool has_parameters(void)
3315 {
3316         /* func(void) is not a parameter */
3317         if (token.type == T_IDENTIFIER) {
3318                 entity_t const *const entity = get_entity(token.symbol, NAMESPACE_NORMAL);
3319                 if (entity == NULL)
3320                         return true;
3321                 if (entity->kind != ENTITY_TYPEDEF)
3322                         return true;
3323                 if (skip_typeref(entity->typedefe.type) != type_void)
3324                         return true;
3325         } else if (token.type != T_void) {
3326                 return true;
3327         }
3328         if (look_ahead(1)->type != ')')
3329                 return true;
3330         next_token();
3331         return false;
3332 }
3333
3334 /**
3335  * Parses function type parameters (and optionally creates variable_t entities
3336  * for them in a scope)
3337  */
3338 static void parse_parameters(function_type_t *type, scope_t *scope)
3339 {
3340         eat('(');
3341         add_anchor_token(')');
3342         int saved_comma_state = save_and_reset_anchor_state(',');
3343
3344         if (token.type == T_IDENTIFIER &&
3345             !is_typedef_symbol(token.symbol)) {
3346                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3347                 if (la1_type == ',' || la1_type == ')') {
3348                         type->kr_style_parameters = true;
3349                         parse_identifier_list(scope);
3350                         goto parameters_finished;
3351                 }
3352         }
3353
3354         if (token.type == ')') {
3355                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3356                 if (!(c_mode & _CXX))
3357                         type->unspecified_parameters = true;
3358         } else if (has_parameters()) {
3359                 function_parameter_t **anchor = &type->parameters;
3360                 do {
3361                         switch (token.type) {
3362                         case T_DOTDOTDOT:
3363                                 next_token();
3364                                 type->variadic = true;
3365                                 goto parameters_finished;
3366
3367                         case T_IDENTIFIER:
3368                         case T___extension__:
3369                         DECLARATION_START
3370                         {
3371                                 entity_t *entity = parse_parameter();
3372                                 if (entity->kind == ENTITY_TYPEDEF) {
3373                                         errorf(&entity->base.source_position,
3374                                                         "typedef not allowed as function parameter");
3375                                         break;
3376                                 }
3377                                 assert(is_declaration(entity));
3378
3379                                 semantic_parameter_incomplete(entity);
3380
3381                                 function_parameter_t *const parameter =
3382                                         allocate_parameter(entity->declaration.type);
3383
3384                                 if (scope != NULL) {
3385                                         append_entity(scope, entity);
3386                                 }
3387
3388                                 *anchor = parameter;
3389                                 anchor  = &parameter->next;
3390                                 break;
3391                         }
3392
3393                         default:
3394                                 goto parameters_finished;
3395                         }
3396                 } while (next_if(','));
3397         }
3398
3399 parameters_finished:
3400         rem_anchor_token(')');
3401         expect(')', end_error);
3402
3403 end_error:
3404         restore_anchor_state(',', saved_comma_state);
3405 }
3406
3407 typedef enum construct_type_kind_t {
3408         CONSTRUCT_INVALID,
3409         CONSTRUCT_POINTER,
3410         CONSTRUCT_REFERENCE,
3411         CONSTRUCT_FUNCTION,
3412         CONSTRUCT_ARRAY
3413 } construct_type_kind_t;
3414
3415 typedef union construct_type_t construct_type_t;
3416
3417 typedef struct construct_type_base_t {
3418         construct_type_kind_t  kind;
3419         source_position_t      pos;
3420         construct_type_t      *next;
3421 } construct_type_base_t;
3422
3423 typedef struct parsed_pointer_t {
3424         construct_type_base_t  base;
3425         type_qualifiers_t      type_qualifiers;
3426         variable_t            *base_variable;  /**< MS __based extension. */
3427 } parsed_pointer_t;
3428
3429 typedef struct parsed_reference_t {
3430         construct_type_base_t base;
3431 } parsed_reference_t;
3432
3433 typedef struct construct_function_type_t {
3434         construct_type_base_t  base;
3435         type_t                *function_type;
3436 } construct_function_type_t;
3437
3438 typedef struct parsed_array_t {
3439         construct_type_base_t  base;
3440         type_qualifiers_t      type_qualifiers;
3441         bool                   is_static;
3442         bool                   is_variable;
3443         expression_t          *size;
3444 } parsed_array_t;
3445
3446 union construct_type_t {
3447         construct_type_kind_t     kind;
3448         construct_type_base_t     base;
3449         parsed_pointer_t          pointer;
3450         parsed_reference_t        reference;
3451         construct_function_type_t function;
3452         parsed_array_t            array;
3453 };
3454
3455 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3456 {
3457         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3458         memset(cons, 0, size);
3459         cons->kind     = kind;
3460         cons->base.pos = *HERE;
3461         return cons;
3462 }
3463
3464 /* §6.7.5.1 */
3465 static construct_type_t *parse_pointer_declarator(void)
3466 {
3467         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3468         eat('*');
3469         cons->pointer.type_qualifiers = parse_type_qualifiers();
3470         //cons->pointer.base_variable   = base_variable;
3471
3472         return cons;
3473 }
3474
3475 /* ISO/IEC 14882:1998(E) §8.3.2 */
3476 static construct_type_t *parse_reference_declarator(void)
3477 {
3478         if (!(c_mode & _CXX))
3479                 errorf(HERE, "references are only available for C++");
3480
3481         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3482         eat('&');
3483
3484         return cons;
3485 }
3486
3487 /* §6.7.5.2 */
3488 static construct_type_t *parse_array_declarator(void)
3489 {
3490         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3491         parsed_array_t   *const array = &cons->array;
3492
3493         eat('[');
3494         add_anchor_token(']');
3495
3496         bool is_static = next_if(T_static);
3497
3498         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3499
3500         if (!is_static)
3501                 is_static = next_if(T_static);
3502
3503         array->type_qualifiers = type_qualifiers;
3504         array->is_static       = is_static;
3505
3506         expression_t *size = NULL;
3507         if (token.type == '*' && look_ahead(1)->type == ']') {
3508                 array->is_variable = true;
3509                 next_token();
3510         } else if (token.type != ']') {
3511                 size = parse_assignment_expression();
3512
3513                 /* §6.7.5.2:1  Array size must have integer type */
3514                 type_t *const orig_type = size->base.type;
3515                 type_t *const type      = skip_typeref(orig_type);
3516                 if (!is_type_integer(type) && is_type_valid(type)) {
3517                         errorf(&size->base.source_position,
3518                                "array size '%E' must have integer type but has type '%T'",
3519                                size, orig_type);
3520                 }
3521
3522                 array->size = size;
3523                 mark_vars_read(size, NULL);
3524         }
3525
3526         if (is_static && size == NULL)
3527                 errorf(&array->base.pos, "static array parameters require a size");
3528
3529         rem_anchor_token(']');
3530         expect(']', end_error);
3531
3532 end_error:
3533         return cons;
3534 }
3535
3536 /* §6.7.5.3 */
3537 static construct_type_t *parse_function_declarator(scope_t *scope)
3538 {
3539         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3540
3541         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3542         function_type_t *ftype = &type->function;
3543
3544         ftype->linkage            = current_linkage;
3545         ftype->calling_convention = CC_DEFAULT;
3546
3547         parse_parameters(ftype, scope);
3548
3549         cons->function.function_type = type;
3550
3551         return cons;
3552 }
3553
3554 typedef struct parse_declarator_env_t {
3555         bool               may_be_abstract : 1;
3556         bool               must_be_abstract : 1;
3557         decl_modifiers_t   modifiers;
3558         symbol_t          *symbol;
3559         source_position_t  source_position;
3560         scope_t            parameters;
3561         attribute_t       *attributes;
3562 } parse_declarator_env_t;
3563
3564 /* §6.7.5 */
3565 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3566 {
3567         /* construct a single linked list of construct_type_t's which describe
3568          * how to construct the final declarator type */
3569         construct_type_t  *first      = NULL;
3570         construct_type_t **anchor     = &first;
3571
3572         env->attributes = parse_attributes(env->attributes);
3573
3574         for (;;) {
3575                 construct_type_t *type;
3576                 //variable_t       *based = NULL; /* MS __based extension */
3577                 switch (token.type) {
3578                         case '&':
3579                                 type = parse_reference_declarator();
3580                                 break;
3581
3582                         case T__based: {
3583                                 panic("based not supported anymore");
3584                                 /* FALLTHROUGH */
3585                         }
3586
3587                         case '*':
3588                                 type = parse_pointer_declarator();
3589                                 break;
3590
3591                         default:
3592                                 goto ptr_operator_end;
3593                 }
3594
3595                 *anchor = type;
3596                 anchor  = &type->base.next;
3597
3598                 /* TODO: find out if this is correct */
3599                 env->attributes = parse_attributes(env->attributes);
3600         }
3601
3602 ptr_operator_end: ;
3603         construct_type_t *inner_types = NULL;
3604
3605         switch (token.type) {
3606         case T_IDENTIFIER:
3607                 if (env->must_be_abstract) {
3608                         errorf(HERE, "no identifier expected in typename");
3609                 } else {
3610                         env->symbol          = token.symbol;
3611                         env->source_position = token.source_position;
3612                 }
3613                 next_token();
3614                 break;
3615
3616         case '(': {
3617                 /* Parenthesized declarator or function declarator? */
3618                 token_t const *const la1 = look_ahead(1);
3619                 switch (la1->type) {
3620                         case T_IDENTIFIER:
3621                                 if (is_typedef_symbol(la1->symbol)) {
3622                         case ')':
3623                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3624                                          * interpreted as ``function with no parameter specification'', rather
3625                                          * than redundant parentheses around the omitted identifier. */
3626                         default:
3627                                         /* Function declarator. */
3628                                         if (!env->may_be_abstract) {
3629                                                 errorf(HERE, "function declarator must have a name");
3630                                         }
3631                                 } else {
3632                         case '&':
3633                         case '(':
3634                         case '*':
3635                         case '[':
3636                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3637                                         /* Paranthesized declarator. */
3638                                         next_token();
3639                                         add_anchor_token(')');
3640                                         inner_types = parse_inner_declarator(env);
3641                                         if (inner_types != NULL) {
3642                                                 /* All later declarators only modify the return type */
3643                                                 env->must_be_abstract = true;
3644                                         }
3645                                         rem_anchor_token(')');
3646                                         expect(')', end_error);
3647                                 }
3648                                 break;
3649                 }
3650                 break;
3651         }
3652
3653         default:
3654                 if (env->may_be_abstract)
3655                         break;
3656                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3657                 eat_until_anchor();
3658                 return NULL;
3659         }
3660
3661         construct_type_t **const p = anchor;
3662
3663         for (;;) {
3664                 construct_type_t *type;
3665                 switch (token.type) {
3666                 case '(': {
3667                         scope_t *scope = NULL;
3668                         if (!env->must_be_abstract) {
3669                                 scope = &env->parameters;
3670                         }
3671
3672                         type = parse_function_declarator(scope);
3673                         break;
3674                 }
3675                 case '[':
3676                         type = parse_array_declarator();
3677                         break;
3678                 default:
3679                         goto declarator_finished;
3680                 }
3681
3682                 /* insert in the middle of the list (at p) */
3683                 type->base.next = *p;
3684                 *p              = type;
3685                 if (anchor == p)
3686                         anchor = &type->base.next;
3687         }
3688
3689 declarator_finished:
3690         /* append inner_types at the end of the list, we don't to set anchor anymore
3691          * as it's not needed anymore */
3692         *anchor = inner_types;
3693
3694         return first;
3695 end_error:
3696         return NULL;
3697 }
3698
3699 static type_t *construct_declarator_type(construct_type_t *construct_list,
3700                                          type_t *type)
3701 {
3702         construct_type_t *iter = construct_list;
3703         for (; iter != NULL; iter = iter->base.next) {
3704                 source_position_t const* const pos = &iter->base.pos;
3705                 switch (iter->kind) {
3706                 case CONSTRUCT_INVALID:
3707                         break;
3708                 case CONSTRUCT_FUNCTION: {
3709                         construct_function_type_t *function      = &iter->function;
3710                         type_t                    *function_type = function->function_type;
3711
3712                         function_type->function.return_type = type;
3713
3714                         type_t *skipped_return_type = skip_typeref(type);
3715                         /* §6.7.5.3:1 */
3716                         if (is_type_function(skipped_return_type)) {
3717                                 errorf(pos, "function returning function is not allowed");
3718                         } else if (is_type_array(skipped_return_type)) {
3719                                 errorf(pos, "function returning array is not allowed");
3720                         } else {
3721                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3722                                         warningf(pos, "type qualifiers in return type of function type are meaningless");
3723                                 }
3724                         }
3725
3726                         /* The function type was constructed earlier.  Freeing it here will
3727                          * destroy other types. */
3728                         type = typehash_insert(function_type);
3729                         continue;
3730                 }
3731
3732                 case CONSTRUCT_POINTER: {
3733                         if (is_type_reference(skip_typeref(type)))
3734                                 errorf(pos, "cannot declare a pointer to reference");
3735
3736                         parsed_pointer_t *pointer = &iter->pointer;
3737                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3738                         continue;
3739                 }
3740
3741                 case CONSTRUCT_REFERENCE:
3742                         if (is_type_reference(skip_typeref(type)))
3743                                 errorf(pos, "cannot declare a reference to reference");
3744
3745                         type = make_reference_type(type);
3746                         continue;
3747
3748                 case CONSTRUCT_ARRAY: {
3749                         if (is_type_reference(skip_typeref(type)))
3750                                 errorf(pos, "cannot declare an array of references");
3751
3752                         parsed_array_t *array      = &iter->array;
3753                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3754
3755                         expression_t *size_expression = array->size;
3756                         if (size_expression != NULL) {
3757                                 size_expression
3758                                         = create_implicit_cast(size_expression, type_size_t);
3759                         }
3760
3761                         array_type->base.qualifiers       = array->type_qualifiers;
3762                         array_type->array.element_type    = type;
3763                         array_type->array.is_static       = array->is_static;
3764                         array_type->array.is_variable     = array->is_variable;
3765                         array_type->array.size_expression = size_expression;
3766
3767                         if (size_expression != NULL) {
3768                                 switch (is_constant_expression(size_expression)) {
3769                                 case EXPR_CLASS_CONSTANT: {
3770                                         long const size = fold_constant_to_int(size_expression);
3771                                         array_type->array.size          = size;
3772                                         array_type->array.size_constant = true;
3773                                         /* §6.7.5.2:1  If the expression is a constant expression,
3774                                          * it shall have a value greater than zero. */
3775                                         if (size < 0) {
3776                                                 errorf(&size_expression->base.source_position,
3777                                                            "size of array must be greater than zero");
3778                                         } else if (size == 0 && !GNU_MODE) {
3779                                                 errorf(&size_expression->base.source_position,
3780                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3781                                         }
3782                                         break;
3783                                 }
3784
3785                                 case EXPR_CLASS_VARIABLE:
3786                                         array_type->array.is_vla = true;
3787                                         break;
3788
3789                                 case EXPR_CLASS_ERROR:
3790                                         break;
3791                                 }
3792                         }
3793
3794                         type_t *skipped_type = skip_typeref(type);
3795                         /* §6.7.5.2:1 */
3796                         if (is_type_incomplete(skipped_type)) {
3797                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3798                         } else if (is_type_function(skipped_type)) {
3799                                 errorf(pos, "array of functions is not allowed");
3800                         }
3801                         type = identify_new_type(array_type);
3802                         continue;
3803                 }
3804                 }
3805                 internal_errorf(pos, "invalid type construction found");
3806         }
3807
3808         return type;
3809 }
3810
3811 static type_t *automatic_type_conversion(type_t *orig_type);
3812
3813 static type_t *semantic_parameter(const source_position_t *pos,
3814                                   type_t *type,
3815                                   const declaration_specifiers_t *specifiers,
3816                                   entity_t const *const param)
3817 {
3818         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3819          *             shall be adjusted to ``qualified pointer to type'',
3820          *             [...]
3821          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3822          *             type'' shall be adjusted to ``pointer to function
3823          *             returning type'', as in 6.3.2.1. */
3824         type = automatic_type_conversion(type);
3825
3826         if (specifiers->is_inline && is_type_valid(type)) {
3827                 errorf(pos, "'%N' declared 'inline'", param);
3828         }
3829
3830         /* §6.9.1:6  The declarations in the declaration list shall contain
3831          *           no storage-class specifier other than register and no
3832          *           initializations. */
3833         if (specifiers->thread_local || (
3834                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3835                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3836            ) {
3837                 errorf(pos, "invalid storage class for '%N'", param);
3838         }
3839
3840         /* delay test for incomplete type, because we might have (void)
3841          * which is legal but incomplete... */
3842
3843         return type;
3844 }
3845
3846 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3847                                   declarator_flags_t flags)
3848 {
3849         parse_declarator_env_t env;
3850         memset(&env, 0, sizeof(env));
3851         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3852
3853         construct_type_t *construct_type = parse_inner_declarator(&env);
3854         type_t           *orig_type      =
3855                 construct_declarator_type(construct_type, specifiers->type);
3856         type_t           *type           = skip_typeref(orig_type);
3857
3858         if (construct_type != NULL) {
3859                 obstack_free(&temp_obst, construct_type);
3860         }
3861
3862         attribute_t *attributes = parse_attributes(env.attributes);
3863         /* append (shared) specifier attribute behind attributes of this
3864          * declarator */
3865         attribute_t **anchor = &attributes;
3866         while (*anchor != NULL)
3867                 anchor = &(*anchor)->next;
3868         *anchor = specifiers->attributes;
3869
3870         entity_t *entity;
3871         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3872                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol);
3873                 entity->base.source_position = env.source_position;
3874                 entity->typedefe.type        = orig_type;
3875
3876                 if (anonymous_entity != NULL) {
3877                         if (is_type_compound(type)) {
3878                                 assert(anonymous_entity->compound.alias == NULL);
3879                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3880                                        anonymous_entity->kind == ENTITY_UNION);
3881                                 anonymous_entity->compound.alias = entity;
3882                                 anonymous_entity = NULL;
3883                         } else if (is_type_enum(type)) {
3884                                 assert(anonymous_entity->enume.alias == NULL);
3885                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3886                                 anonymous_entity->enume.alias = entity;
3887                                 anonymous_entity = NULL;
3888                         }
3889                 }
3890         } else {
3891                 /* create a declaration type entity */
3892                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3893                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol);
3894
3895                         if (env.symbol != NULL) {
3896                                 if (specifiers->is_inline && is_type_valid(type)) {
3897                                         errorf(&env.source_position,
3898                                                         "compound member '%Y' declared 'inline'", env.symbol);
3899                                 }
3900
3901                                 if (specifiers->thread_local ||
3902                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3903                                         errorf(&env.source_position,
3904                                                         "compound member '%Y' must have no storage class",
3905                                                         env.symbol);
3906                                 }
3907                         }
3908                 } else if (flags & DECL_IS_PARAMETER) {
3909                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol);
3910                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3911                 } else if (is_type_function(type)) {
3912                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol);
3913                         entity->function.is_inline      = specifiers->is_inline;
3914                         entity->function.elf_visibility = default_visibility;
3915                         entity->function.parameters     = env.parameters;
3916
3917                         if (env.symbol != NULL) {
3918                                 /* this needs fixes for C++ */
3919                                 bool in_function_scope = current_function != NULL;
3920
3921                                 if (specifiers->thread_local || (
3922                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3923                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3924                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3925                                                 )) {
3926                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3927                                 }
3928                         }
3929                 } else {
3930                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol);
3931                         entity->variable.elf_visibility = default_visibility;
3932                         entity->variable.thread_local   = specifiers->thread_local;
3933
3934                         if (env.symbol != NULL) {
3935                                 if (specifiers->is_inline && is_type_valid(type)) {
3936                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3937                                 }
3938
3939                                 bool invalid_storage_class = false;
3940                                 if (current_scope == file_scope) {
3941                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3942                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3943                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3944                                                 invalid_storage_class = true;
3945                                         }
3946                                 } else {
3947                                         if (specifiers->thread_local &&
3948                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3949                                                 invalid_storage_class = true;
3950                                         }
3951                                 }
3952                                 if (invalid_storage_class) {
3953                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3954                                 }
3955                         }
3956                 }
3957
3958                 entity->base.source_position   = env.symbol != NULL ? env.source_position : specifiers->source_position;
3959                 entity->declaration.type       = orig_type;
3960                 entity->declaration.alignment  = get_type_alignment(orig_type);
3961                 entity->declaration.modifiers  = env.modifiers;
3962                 entity->declaration.attributes = attributes;
3963
3964                 storage_class_t storage_class = specifiers->storage_class;
3965                 entity->declaration.declared_storage_class = storage_class;
3966
3967                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3968                         storage_class = STORAGE_CLASS_AUTO;
3969                 entity->declaration.storage_class = storage_class;
3970         }
3971
3972         if (attributes != NULL) {
3973                 handle_entity_attributes(attributes, entity);
3974         }
3975
3976         return entity;
3977 }
3978
3979 static type_t *parse_abstract_declarator(type_t *base_type)
3980 {
3981         parse_declarator_env_t env;
3982         memset(&env, 0, sizeof(env));
3983         env.may_be_abstract = true;
3984         env.must_be_abstract = true;
3985
3986         construct_type_t *construct_type = parse_inner_declarator(&env);
3987
3988         type_t *result = construct_declarator_type(construct_type, base_type);
3989         if (construct_type != NULL) {
3990                 obstack_free(&temp_obst, construct_type);
3991         }
3992         result = handle_type_attributes(env.attributes, result);
3993
3994         return result;
3995 }
3996
3997 /**
3998  * Check if the declaration of main is suspicious.  main should be a
3999  * function with external linkage, returning int, taking either zero
4000  * arguments, two, or three arguments of appropriate types, ie.
4001  *
4002  * int main([ int argc, char **argv [, char **env ] ]).
4003  *
4004  * @param decl    the declaration to check
4005  * @param type    the function type of the declaration
4006  */
4007 static void check_main(const entity_t *entity)
4008 {
4009         const source_position_t *pos = &entity->base.source_position;
4010         if (entity->kind != ENTITY_FUNCTION) {
4011                 warningf(pos, "'main' is not a function");
4012                 return;
4013         }
4014
4015         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4016                 warningf(pos, "'main' is normally a non-static function");
4017         }
4018
4019         type_t *type = skip_typeref(entity->declaration.type);
4020         assert(is_type_function(type));
4021
4022         function_type_t *func_type = &type->function;
4023         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4024                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4025                          func_type->return_type);
4026         }
4027         const function_parameter_t *parm = func_type->parameters;
4028         if (parm != NULL) {
4029                 type_t *const first_type        = skip_typeref(parm->type);
4030                 type_t *const first_type_unqual = get_unqualified_type(first_type);
4031                 if (!types_compatible(first_type_unqual, type_int)) {
4032                         warningf(pos,
4033                                  "first argument of 'main' should be 'int', but is '%T'",
4034                                  parm->type);
4035                 }
4036                 parm = parm->next;
4037                 if (parm != NULL) {
4038                         type_t *const second_type = skip_typeref(parm->type);
4039                         type_t *const second_type_unqual
4040                                 = get_unqualified_type(second_type);
4041                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
4042                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'",
4043                                          parm->type);
4044                         }
4045                         parm = parm->next;
4046                         if (parm != NULL) {
4047                                 type_t *const third_type = skip_typeref(parm->type);
4048                                 type_t *const third_type_unqual
4049                                         = get_unqualified_type(third_type);
4050                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
4051                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'",
4052                                                  parm->type);
4053                                 }
4054                                 parm = parm->next;
4055                                 if (parm != NULL)
4056                                         goto warn_arg_count;
4057                         }
4058                 } else {
4059 warn_arg_count:
4060                         warningf(pos, "'main' takes only zero, two or three arguments");
4061                 }
4062         }
4063 }
4064
4065 /**
4066  * Check if a symbol is the equal to "main".
4067  */
4068 static bool is_sym_main(const symbol_t *const sym)
4069 {
4070         return strcmp(sym->string, "main") == 0;
4071 }
4072
4073 static void error_redefined_as_different_kind(const source_position_t *pos,
4074                 const entity_t *old, entity_kind_t new_kind)
4075 {
4076         char              const *const what = get_entity_kind_name(new_kind);
4077         source_position_t const *const ppos = &old->base.source_position;
4078         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
4079 }
4080
4081 static bool is_entity_valid(entity_t *const ent)
4082 {
4083         if (is_declaration(ent)) {
4084                 return is_type_valid(skip_typeref(ent->declaration.type));
4085         } else if (ent->kind == ENTITY_TYPEDEF) {
4086                 return is_type_valid(skip_typeref(ent->typedefe.type));
4087         }
4088         return true;
4089 }
4090
4091 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
4092 {
4093         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
4094                 if (attributes_equal(tattr, attr))
4095                         return true;
4096         }
4097         return false;
4098 }
4099
4100 /**
4101  * test wether new_list contains any attributes not included in old_list
4102  */
4103 static bool has_new_attributes(const attribute_t *old_list,
4104                                const attribute_t *new_list)
4105 {
4106         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
4107                 if (!contains_attribute(old_list, attr))
4108                         return true;
4109         }
4110         return false;
4111 }
4112
4113 /**
4114  * Merge in attributes from an attribute list (probably from a previous
4115  * declaration with the same name). Warning: destroys the old structure
4116  * of the attribute list - don't reuse attributes after this call.
4117  */
4118 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4119 {
4120         attribute_t *next;
4121         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4122                 next = attr->next;
4123                 if (contains_attribute(decl->attributes, attr))
4124                         continue;
4125
4126                 /* move attribute to new declarations attributes list */
4127                 attr->next       = decl->attributes;
4128                 decl->attributes = attr;
4129         }
4130 }
4131
4132 /**
4133  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4134  * for various problems that occur for multiple definitions
4135  */
4136 entity_t *record_entity(entity_t *entity, const bool is_definition)
4137 {
4138         const symbol_t *const    symbol  = entity->base.symbol;
4139         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4140         const source_position_t *pos     = &entity->base.source_position;
4141
4142         /* can happen in error cases */
4143         if (symbol == NULL)
4144                 return entity;
4145
4146         entity_t *const previous_entity = get_entity(symbol, namespc);
4147         /* pushing the same entity twice will break the stack structure */
4148         assert(previous_entity != entity);
4149
4150         if (entity->kind == ENTITY_FUNCTION) {
4151                 type_t *const orig_type = entity->declaration.type;
4152                 type_t *const type      = skip_typeref(orig_type);
4153
4154                 assert(is_type_function(type));
4155                 if (type->function.unspecified_parameters &&
4156                                 warning.strict_prototypes             &&
4157                     previous_entity == NULL               &&
4158                     !entity->declaration.implicit) {
4159                         warningf(pos, "function declaration '%#N' is not a prototype", entity);
4160                 }
4161
4162                 if (warning.main && current_scope == file_scope
4163                                 && is_sym_main(symbol)) {
4164                         check_main(entity);
4165                 }
4166         }
4167
4168         if (is_declaration(entity)                                    &&
4169             warning.nested_externs                                    &&
4170             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4171             current_scope != file_scope                               &&
4172             !entity->declaration.implicit) {
4173                 warningf(pos, "nested extern declaration of '%#N'", entity);
4174         }
4175
4176         if (previous_entity != NULL) {
4177                 source_position_t const *const ppos = &previous_entity->base.source_position;
4178
4179                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4180                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4181                         assert(previous_entity->kind == ENTITY_PARAMETER);
4182                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4183                         goto finish;
4184                 }
4185
4186                 if (previous_entity->base.parent_scope == current_scope) {
4187                         if (previous_entity->kind != entity->kind) {
4188                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4189                                         error_redefined_as_different_kind(pos, previous_entity,
4190                                                         entity->kind);
4191                                 }
4192                                 goto finish;
4193                         }
4194                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4195                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4196                                 goto finish;
4197                         }
4198                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4199                                 /* TODO: C++ allows this for exactly the same type */
4200                                 errorf(pos, "redefinition of '%N' (declared %P)", entity, ppos);
4201                                 goto finish;
4202                         }
4203
4204                         /* at this point we should have only VARIABLES or FUNCTIONS */
4205                         assert(is_declaration(previous_entity) && is_declaration(entity));
4206
4207                         declaration_t *const prev_decl = &previous_entity->declaration;
4208                         declaration_t *const decl      = &entity->declaration;
4209
4210                         /* can happen for K&R style declarations */
4211                         if (prev_decl->type       == NULL             &&
4212                                         previous_entity->kind == ENTITY_PARAMETER &&
4213                                         entity->kind          == ENTITY_PARAMETER) {
4214                                 prev_decl->type                   = decl->type;
4215                                 prev_decl->storage_class          = decl->storage_class;
4216                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4217                                 prev_decl->modifiers              = decl->modifiers;
4218                                 return previous_entity;
4219                         }
4220
4221                         type_t *const type      = skip_typeref(decl->type);
4222                         type_t *const prev_type = skip_typeref(prev_decl->type);
4223
4224                         if (!types_compatible(type, prev_type)) {
4225                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4226                         } else {
4227                                 unsigned old_storage_class = prev_decl->storage_class;
4228
4229                                 if (warning.redundant_decls               &&
4230                                                 is_definition                     &&
4231                                                 !prev_decl->used                  &&
4232                                                 !(prev_decl->modifiers & DM_USED) &&
4233                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4234                                         warningf(ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4235                                 }
4236
4237                                 storage_class_t new_storage_class = decl->storage_class;
4238
4239                                 /* pretend no storage class means extern for function
4240                                  * declarations (except if the previous declaration is neither
4241                                  * none nor extern) */
4242                                 if (entity->kind == ENTITY_FUNCTION) {
4243                                         /* the previous declaration could have unspecified parameters or
4244                                          * be a typedef, so use the new type */
4245                                         if (prev_type->function.unspecified_parameters || is_definition)
4246                                                 prev_decl->type = type;
4247
4248                                         switch (old_storage_class) {
4249                                                 case STORAGE_CLASS_NONE:
4250                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4251                                                         /* FALLTHROUGH */
4252
4253                                                 case STORAGE_CLASS_EXTERN:
4254                                                         if (is_definition) {
4255                                                                 if (warning.missing_prototypes &&
4256                                                                                 prev_type->function.unspecified_parameters &&
4257                                                                                 !is_sym_main(symbol)) {
4258                                                                         warningf(pos, "no previous prototype for '%#N'", entity);
4259                                                                 }
4260                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4261                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4262                                                         }
4263                                                         break;
4264
4265                                                 default:
4266                                                         break;
4267                                         }
4268                                 } else if (is_type_incomplete(prev_type)) {
4269                                         prev_decl->type = type;
4270                                 }
4271
4272                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4273                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4274
4275 warn_redundant_declaration: ;
4276                                         bool has_new_attrs
4277                                                 = has_new_attributes(prev_decl->attributes,
4278                                                                      decl->attributes);
4279                                         if (has_new_attrs) {
4280                                                 merge_in_attributes(decl, prev_decl->attributes);
4281                                         } else if (!is_definition        &&
4282                                                         warning.redundant_decls  &&
4283                                                         is_type_valid(prev_type) &&
4284                                                         strcmp(ppos->input_name, "<builtin>") != 0) {
4285                                                 warningf(pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4286                                         }
4287                                 } else if (current_function == NULL) {
4288                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4289                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4290                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4291                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4292                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4293                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4294                                         } else {
4295                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4296                                                 if (c_mode & _CXX)
4297                                                         goto error_redeclaration;
4298                                                 goto warn_redundant_declaration;
4299                                         }
4300                                 } else if (is_type_valid(prev_type)) {
4301                                         if (old_storage_class == new_storage_class) {
4302 error_redeclaration:
4303                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4304                                         } else {
4305                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4306                                         }
4307                                 }
4308                         }
4309
4310                         prev_decl->modifiers |= decl->modifiers;
4311                         if (entity->kind == ENTITY_FUNCTION) {
4312                                 previous_entity->function.is_inline |= entity->function.is_inline;
4313                         }
4314                         return previous_entity;
4315                 }
4316
4317                 if (warning.shadow ||
4318                                 (warning.shadow_local && previous_entity->base.parent_scope != file_scope)) {
4319                         char const *const what = get_entity_kind_name(previous_entity->kind);
4320                         warningf(pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4321                 }
4322         }
4323
4324         if (entity->kind == ENTITY_FUNCTION) {
4325                 if (is_definition &&
4326                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4327                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4328                                 warningf(pos, "no previous prototype for '%#N'", entity);
4329                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4330                                 warningf(pos, "no previous declaration for '%#N'", entity);
4331                         }
4332                 }
4333         } else if (entity->kind == ENTITY_VARIABLE) {
4334                 if (warning.missing_declarations &&
4335               current_scope == file_scope  &&
4336               entity->declaration.storage_class == STORAGE_CLASS_NONE) {
4337                         warningf(pos, "no previous declaration for '%#N'", entity);
4338                 }
4339         }
4340
4341 finish:
4342         assert(entity->base.parent_scope == NULL);
4343         assert(current_scope != NULL);
4344
4345         entity->base.parent_scope = current_scope;
4346         environment_push(entity);
4347         append_entity(current_scope, entity);
4348
4349         return entity;
4350 }
4351
4352 static void parser_error_multiple_definition(entity_t *entity,
4353                 const source_position_t *source_position)
4354 {
4355         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4356                entity->base.symbol, &entity->base.source_position);
4357 }
4358
4359 static bool is_declaration_specifier(const token_t *token)
4360 {
4361         switch (token->type) {
4362                 DECLARATION_START
4363                         return true;
4364                 case T_IDENTIFIER:
4365                         return is_typedef_symbol(token->symbol);
4366
4367                 default:
4368                         return false;
4369         }
4370 }
4371
4372 static void parse_init_declarator_rest(entity_t *entity)
4373 {
4374         type_t *orig_type = type_error_type;
4375
4376         if (entity->base.kind == ENTITY_TYPEDEF) {
4377                 source_position_t const *const pos = &entity->base.source_position;
4378                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4379         } else {
4380                 assert(is_declaration(entity));
4381                 orig_type = entity->declaration.type;
4382         }
4383
4384         type_t *type = skip_typeref(orig_type);
4385
4386         if (entity->kind == ENTITY_VARIABLE
4387                         && entity->variable.initializer != NULL) {
4388                 parser_error_multiple_definition(entity, HERE);
4389         }
4390         eat('=');
4391
4392         declaration_t *const declaration = &entity->declaration;
4393         bool must_be_constant = false;
4394         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4395             entity->base.parent_scope  == file_scope) {
4396                 must_be_constant = true;
4397         }
4398
4399         if (is_type_function(type)) {
4400                 source_position_t const *const pos = &entity->base.source_position;
4401                 errorf(pos, "'%N' is initialized like a variable", entity);
4402                 orig_type = type_error_type;
4403         }
4404
4405         parse_initializer_env_t env;
4406         env.type             = orig_type;
4407         env.must_be_constant = must_be_constant;
4408         env.entity           = entity;
4409         current_init_decl    = entity;
4410
4411         initializer_t *initializer = parse_initializer(&env);
4412         current_init_decl = NULL;
4413
4414         if (entity->kind == ENTITY_VARIABLE) {
4415                 /* §6.7.5:22  array initializers for arrays with unknown size
4416                  * determine the array type size */
4417                 declaration->type            = env.type;
4418                 entity->variable.initializer = initializer;
4419         }
4420 }
4421
4422 /* parse rest of a declaration without any declarator */
4423 static void parse_anonymous_declaration_rest(
4424                 const declaration_specifiers_t *specifiers)
4425 {
4426         eat(';');
4427         anonymous_entity = NULL;
4428
4429         if (warning.other) {
4430                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4431                                 specifiers->thread_local) {
4432                         warningf(&specifiers->source_position,
4433                                  "useless storage class in empty declaration");
4434                 }
4435
4436                 type_t *type = specifiers->type;
4437                 switch (type->kind) {
4438                         case TYPE_COMPOUND_STRUCT:
4439                         case TYPE_COMPOUND_UNION: {
4440                                 if (type->compound.compound->base.symbol == NULL) {
4441                                         warningf(&specifiers->source_position,
4442                                                  "unnamed struct/union that defines no instances");
4443                                 }
4444                                 break;
4445                         }
4446
4447                         case TYPE_ENUM:
4448                                 break;
4449
4450                         default:
4451                                 warningf(&specifiers->source_position, "empty declaration");
4452                                 break;
4453                 }
4454         }
4455 }
4456
4457 static void check_variable_type_complete(entity_t *ent)
4458 {
4459         if (ent->kind != ENTITY_VARIABLE)
4460                 return;
4461
4462         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4463          *         type for the object shall be complete [...] */
4464         declaration_t *decl = &ent->declaration;
4465         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4466                         decl->storage_class == STORAGE_CLASS_STATIC)
4467                 return;
4468
4469         type_t *const type = skip_typeref(decl->type);
4470         if (!is_type_incomplete(type))
4471                 return;
4472
4473         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4474          * are given length one. */
4475         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4476                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4477                 return;
4478         }
4479
4480         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4481 }
4482
4483
4484 static void parse_declaration_rest(entity_t *ndeclaration,
4485                 const declaration_specifiers_t *specifiers,
4486                 parsed_declaration_func         finished_declaration,
4487                 declarator_flags_t              flags)
4488 {
4489         add_anchor_token(';');
4490         add_anchor_token(',');
4491         while (true) {
4492                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4493
4494                 if (token.type == '=') {
4495                         parse_init_declarator_rest(entity);
4496                 } else if (entity->kind == ENTITY_VARIABLE) {
4497                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4498                          * [...] where the extern specifier is explicitly used. */
4499                         declaration_t *decl = &entity->declaration;
4500                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4501                                 type_t *type = decl->type;
4502                                 if (is_type_reference(skip_typeref(type))) {
4503                                         source_position_t const *const pos = &entity->base.source_position;
4504                                         errorf(pos, "reference '%#N' must be initialized", entity);
4505                                 }
4506                         }
4507                 }
4508
4509                 check_variable_type_complete(entity);
4510
4511                 if (!next_if(','))
4512                         break;
4513
4514                 add_anchor_token('=');
4515                 ndeclaration = parse_declarator(specifiers, flags);
4516                 rem_anchor_token('=');
4517         }
4518         expect(';', end_error);
4519
4520 end_error:
4521         anonymous_entity = NULL;
4522         rem_anchor_token(';');
4523         rem_anchor_token(',');
4524 }
4525
4526 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4527 {
4528         symbol_t *symbol = entity->base.symbol;
4529         if (symbol == NULL)
4530                 return entity;
4531
4532         assert(entity->base.namespc == NAMESPACE_NORMAL);
4533         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4534         if (previous_entity == NULL
4535                         || previous_entity->base.parent_scope != current_scope) {
4536                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4537                        symbol);
4538                 return entity;
4539         }
4540
4541         if (is_definition) {
4542                 errorf(HERE, "'%N' is initialised", entity);
4543         }
4544
4545         return record_entity(entity, false);
4546 }
4547
4548 static void parse_declaration(parsed_declaration_func finished_declaration,
4549                               declarator_flags_t      flags)
4550 {
4551         add_anchor_token(';');
4552         declaration_specifiers_t specifiers;
4553         parse_declaration_specifiers(&specifiers);
4554         rem_anchor_token(';');
4555
4556         if (token.type == ';') {
4557                 parse_anonymous_declaration_rest(&specifiers);
4558         } else {
4559                 entity_t *entity = parse_declarator(&specifiers, flags);
4560                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4561         }
4562 }
4563
4564 /* §6.5.2.2:6 */
4565 static type_t *get_default_promoted_type(type_t *orig_type)
4566 {
4567         type_t *result = orig_type;
4568
4569         type_t *type = skip_typeref(orig_type);
4570         if (is_type_integer(type)) {
4571                 result = promote_integer(type);
4572         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4573                 result = type_double;
4574         }
4575
4576         return result;
4577 }
4578
4579 static void parse_kr_declaration_list(entity_t *entity)
4580 {
4581         if (entity->kind != ENTITY_FUNCTION)
4582                 return;
4583
4584         type_t *type = skip_typeref(entity->declaration.type);
4585         assert(is_type_function(type));
4586         if (!type->function.kr_style_parameters)
4587                 return;
4588
4589         add_anchor_token('{');
4590
4591         /* push function parameters */
4592         size_t const  top       = environment_top();
4593         scope_t      *old_scope = scope_push(&entity->function.parameters);
4594
4595         entity_t *parameter = entity->function.parameters.entities;
4596         for ( ; parameter != NULL; parameter = parameter->base.next) {
4597                 assert(parameter->base.parent_scope == NULL);
4598                 parameter->base.parent_scope = current_scope;
4599                 environment_push(parameter);
4600         }
4601
4602         /* parse declaration list */
4603         for (;;) {
4604                 switch (token.type) {
4605                         DECLARATION_START
4606                         case T___extension__:
4607                         /* This covers symbols, which are no type, too, and results in
4608                          * better error messages.  The typical cases are misspelled type
4609                          * names and missing includes. */
4610                         case T_IDENTIFIER:
4611                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4612                                 break;
4613                         default:
4614                                 goto decl_list_end;
4615                 }
4616         }
4617 decl_list_end:
4618
4619         /* pop function parameters */
4620         assert(current_scope == &entity->function.parameters);
4621         scope_pop(old_scope);
4622         environment_pop_to(top);
4623
4624         /* update function type */
4625         type_t *new_type = duplicate_type(type);
4626
4627         function_parameter_t  *parameters = NULL;
4628         function_parameter_t **anchor     = &parameters;
4629
4630         /* did we have an earlier prototype? */
4631         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4632         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4633                 proto_type = NULL;
4634
4635         function_parameter_t *proto_parameter = NULL;
4636         if (proto_type != NULL) {
4637                 type_t *proto_type_type = proto_type->declaration.type;
4638                 proto_parameter         = proto_type_type->function.parameters;
4639                 /* If a K&R function definition has a variadic prototype earlier, then
4640                  * make the function definition variadic, too. This should conform to
4641                  * §6.7.5.3:15 and §6.9.1:8. */
4642                 new_type->function.variadic = proto_type_type->function.variadic;
4643         } else {
4644                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4645                  * prototype */
4646                 new_type->function.unspecified_parameters = true;
4647         }
4648
4649         bool need_incompatible_warning = false;
4650         parameter = entity->function.parameters.entities;
4651         for (; parameter != NULL; parameter = parameter->base.next,
4652                         proto_parameter =
4653                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4654                 if (parameter->kind != ENTITY_PARAMETER)
4655                         continue;
4656
4657                 type_t *parameter_type = parameter->declaration.type;
4658                 if (parameter_type == NULL) {
4659                         source_position_t const* const pos = &parameter->base.source_position;
4660                         if (strict_mode) {
4661                                 errorf(pos, "no type specified for function '%N'", parameter);
4662                                 parameter_type = type_error_type;
4663                         } else {
4664                                 if (warning.implicit_int) {
4665                                         warningf(pos, "no type specified for function '%N', using 'int'", parameter);
4666                                 }
4667                                 parameter_type = type_int;
4668                         }
4669                         parameter->declaration.type = parameter_type;
4670                 }
4671
4672                 semantic_parameter_incomplete(parameter);
4673
4674                 /* we need the default promoted types for the function type */
4675                 type_t *not_promoted = parameter_type;
4676                 parameter_type       = get_default_promoted_type(parameter_type);
4677
4678                 /* gcc special: if the type of the prototype matches the unpromoted
4679                  * type don't promote */
4680                 if (!strict_mode && proto_parameter != NULL) {
4681                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4682                         type_t *promo_skip   = skip_typeref(parameter_type);
4683                         type_t *param_skip   = skip_typeref(not_promoted);
4684                         if (!types_compatible(proto_p_type, promo_skip)
4685                                 && types_compatible(proto_p_type, param_skip)) {
4686                                 /* don't promote */
4687                                 need_incompatible_warning = true;
4688                                 parameter_type = not_promoted;
4689                         }
4690                 }
4691                 function_parameter_t *const function_parameter
4692                         = allocate_parameter(parameter_type);
4693
4694                 *anchor = function_parameter;
4695                 anchor  = &function_parameter->next;
4696         }
4697
4698         new_type->function.parameters = parameters;
4699         new_type = identify_new_type(new_type);
4700
4701         if (warning.other && need_incompatible_warning) {
4702                 source_position_t const *const pos  = &entity->base.source_position;
4703                 source_position_t const *const ppos = &proto_type->base.source_position;
4704                 symbol_t          const *const sym  = entity->base.symbol;
4705                 warningf(pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4706         }
4707         entity->declaration.type = new_type;
4708
4709         rem_anchor_token('{');
4710 }
4711
4712 static bool first_err = true;
4713
4714 /**
4715  * When called with first_err set, prints the name of the current function,
4716  * else does noting.
4717  */
4718 static void print_in_function(void)
4719 {
4720         if (first_err) {
4721                 first_err = false;
4722                 char const *const file = current_function->base.base.source_position.input_name;
4723                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4724         }
4725 }
4726
4727 /**
4728  * Check if all labels are defined in the current function.
4729  * Check if all labels are used in the current function.
4730  */
4731 static void check_labels(void)
4732 {
4733         for (const goto_statement_t *goto_statement = goto_first;
4734             goto_statement != NULL;
4735             goto_statement = goto_statement->next) {
4736                 /* skip computed gotos */
4737                 if (goto_statement->expression != NULL)
4738                         continue;
4739
4740                 label_t *label = goto_statement->label;
4741                 if (label->base.source_position.input_name == NULL) {
4742                         print_in_function();
4743                         source_position_t const *const pos = &goto_statement->base.source_position;
4744                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4745                  }
4746         }
4747
4748         if (warning.unused_label) {
4749                 for (const label_statement_t *label_statement = label_first;
4750                          label_statement != NULL;
4751                          label_statement = label_statement->next) {
4752                         label_t *label = label_statement->label;
4753
4754                         if (! label->used) {
4755                                 print_in_function();
4756                                 source_position_t const *const pos = &label_statement->base.source_position;
4757                                 warningf(pos, "'%N' defined but not used", (entity_t const*)label);
4758                         }
4759                 }
4760         }
4761 }
4762
4763 static void warn_unused_entity(entity_t *entity, entity_t *last)
4764 {
4765         entity_t const *const end = last != NULL ? last->base.next : NULL;
4766         for (; entity != end; entity = entity->base.next) {
4767                 if (!is_declaration(entity))
4768                         continue;
4769
4770                 declaration_t *declaration = &entity->declaration;
4771                 if (declaration->implicit)
4772                         continue;
4773
4774                 if (!declaration->used) {
4775                         print_in_function();
4776                         warningf(&entity->base.source_position, "'%N' is unused", entity);
4777                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4778                         print_in_function();
4779                         warningf(&entity->base.source_position, "'%N' is never read", entity);
4780                 }
4781         }
4782 }
4783
4784 static void check_unused_variables(statement_t *const stmt, void *const env)
4785 {
4786         (void)env;
4787
4788         switch (stmt->kind) {
4789                 case STATEMENT_DECLARATION: {
4790                         declaration_statement_t const *const decls = &stmt->declaration;
4791                         warn_unused_entity(decls->declarations_begin,
4792                                            decls->declarations_end);
4793                         return;
4794                 }
4795
4796                 case STATEMENT_FOR:
4797                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4798                         return;
4799
4800                 default:
4801                         return;
4802         }
4803 }
4804
4805 /**
4806  * Check declarations of current_function for unused entities.
4807  */
4808 static void check_declarations(void)
4809 {
4810         if (warning.unused_parameter) {
4811                 const scope_t *scope = &current_function->parameters;
4812
4813                 /* do not issue unused warnings for main */
4814                 if (!is_sym_main(current_function->base.base.symbol)) {
4815                         warn_unused_entity(scope->entities, NULL);
4816                 }
4817         }
4818         if (warning.unused_variable) {
4819                 walk_statements(current_function->statement, check_unused_variables,
4820                                 NULL);
4821         }
4822 }
4823
4824 static int determine_truth(expression_t const* const cond)
4825 {
4826         return
4827                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4828                 fold_constant_to_bool(cond)                         ? 1 :
4829                 -1;
4830 }
4831
4832 static void check_reachable(statement_t *);
4833 static bool reaches_end;
4834
4835 static bool expression_returns(expression_t const *const expr)
4836 {
4837         switch (expr->kind) {
4838                 case EXPR_CALL: {
4839                         expression_t const *const func = expr->call.function;
4840                         if (func->kind == EXPR_REFERENCE) {
4841                                 entity_t *entity = func->reference.entity;
4842                                 if (entity->kind == ENTITY_FUNCTION
4843                                                 && entity->declaration.modifiers & DM_NORETURN)
4844                                         return false;
4845                         }
4846
4847                         if (!expression_returns(func))
4848                                 return false;
4849
4850                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4851                                 if (!expression_returns(arg->expression))
4852                                         return false;
4853                         }
4854
4855                         return true;
4856                 }
4857
4858                 case EXPR_REFERENCE:
4859                 case EXPR_REFERENCE_ENUM_VALUE:
4860                 EXPR_LITERAL_CASES
4861                 case EXPR_STRING_LITERAL:
4862                 case EXPR_WIDE_STRING_LITERAL:
4863                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4864                 case EXPR_LABEL_ADDRESS:
4865                 case EXPR_CLASSIFY_TYPE:
4866                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4867                 case EXPR_ALIGNOF:
4868                 case EXPR_FUNCNAME:
4869                 case EXPR_BUILTIN_CONSTANT_P:
4870                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4871                 case EXPR_OFFSETOF:
4872                 case EXPR_INVALID:
4873                         return true;
4874
4875                 case EXPR_STATEMENT: {
4876                         bool old_reaches_end = reaches_end;
4877                         reaches_end = false;
4878                         check_reachable(expr->statement.statement);
4879                         bool returns = reaches_end;
4880                         reaches_end = old_reaches_end;
4881                         return returns;
4882                 }
4883
4884                 case EXPR_CONDITIONAL:
4885                         // TODO handle constant expression
4886
4887                         if (!expression_returns(expr->conditional.condition))
4888                                 return false;
4889
4890                         if (expr->conditional.true_expression != NULL
4891                                         && expression_returns(expr->conditional.true_expression))
4892                                 return true;
4893
4894                         return expression_returns(expr->conditional.false_expression);
4895
4896                 case EXPR_SELECT:
4897                         return expression_returns(expr->select.compound);
4898
4899                 case EXPR_ARRAY_ACCESS:
4900                         return
4901                                 expression_returns(expr->array_access.array_ref) &&
4902                                 expression_returns(expr->array_access.index);
4903
4904                 case EXPR_VA_START:
4905                         return expression_returns(expr->va_starte.ap);
4906
4907                 case EXPR_VA_ARG:
4908                         return expression_returns(expr->va_arge.ap);
4909
4910                 case EXPR_VA_COPY:
4911                         return expression_returns(expr->va_copye.src);
4912
4913                 EXPR_UNARY_CASES_MANDATORY
4914                         return expression_returns(expr->unary.value);
4915
4916                 case EXPR_UNARY_THROW:
4917                         return false;
4918
4919                 EXPR_BINARY_CASES
4920                         // TODO handle constant lhs of && and ||
4921                         return
4922                                 expression_returns(expr->binary.left) &&
4923                                 expression_returns(expr->binary.right);
4924
4925                 case EXPR_UNKNOWN:
4926                         break;
4927         }
4928
4929         panic("unhandled expression");
4930 }
4931
4932 static bool initializer_returns(initializer_t const *const init)
4933 {
4934         switch (init->kind) {
4935                 case INITIALIZER_VALUE:
4936                         return expression_returns(init->value.value);
4937
4938                 case INITIALIZER_LIST: {
4939                         initializer_t * const*       i       = init->list.initializers;
4940                         initializer_t * const* const end     = i + init->list.len;
4941                         bool                         returns = true;
4942                         for (; i != end; ++i) {
4943                                 if (!initializer_returns(*i))
4944                                         returns = false;
4945                         }
4946                         return returns;
4947                 }
4948
4949                 case INITIALIZER_STRING:
4950                 case INITIALIZER_WIDE_STRING:
4951                 case INITIALIZER_DESIGNATOR: // designators have no payload
4952                         return true;
4953         }
4954         panic("unhandled initializer");
4955 }
4956
4957 static bool noreturn_candidate;
4958
4959 static void check_reachable(statement_t *const stmt)
4960 {
4961         if (stmt->base.reachable)
4962                 return;
4963         if (stmt->kind != STATEMENT_DO_WHILE)
4964                 stmt->base.reachable = true;
4965
4966         statement_t *last = stmt;
4967         statement_t *next;
4968         switch (stmt->kind) {
4969                 case STATEMENT_INVALID:
4970                 case STATEMENT_EMPTY:
4971                 case STATEMENT_ASM:
4972                         next = stmt->base.next;
4973                         break;
4974
4975                 case STATEMENT_DECLARATION: {
4976                         declaration_statement_t const *const decl = &stmt->declaration;
4977                         entity_t                const *      ent  = decl->declarations_begin;
4978                         entity_t                const *const last_decl = decl->declarations_end;
4979                         if (ent != NULL) {
4980                                 for (;; ent = ent->base.next) {
4981                                         if (ent->kind                 == ENTITY_VARIABLE &&
4982                                             ent->variable.initializer != NULL            &&
4983                                             !initializer_returns(ent->variable.initializer)) {
4984                                                 return;
4985                                         }
4986                                         if (ent == last_decl)
4987                                                 break;
4988                                 }
4989                         }
4990                         next = stmt->base.next;
4991                         break;
4992                 }
4993
4994                 case STATEMENT_COMPOUND:
4995                         next = stmt->compound.statements;
4996                         if (next == NULL)
4997                                 next = stmt->base.next;
4998                         break;
4999
5000                 case STATEMENT_RETURN: {
5001                         expression_t const *const val = stmt->returns.value;
5002                         if (val == NULL || expression_returns(val))
5003                                 noreturn_candidate = false;
5004                         return;
5005                 }
5006
5007                 case STATEMENT_IF: {
5008                         if_statement_t const *const ifs  = &stmt->ifs;
5009                         expression_t   const *const cond = ifs->condition;
5010
5011                         if (!expression_returns(cond))
5012                                 return;
5013
5014                         int const val = determine_truth(cond);
5015
5016                         if (val >= 0)
5017                                 check_reachable(ifs->true_statement);
5018
5019                         if (val > 0)
5020                                 return;
5021
5022                         if (ifs->false_statement != NULL) {
5023                                 check_reachable(ifs->false_statement);
5024                                 return;
5025                         }
5026
5027                         next = stmt->base.next;
5028                         break;
5029                 }
5030
5031                 case STATEMENT_SWITCH: {
5032                         switch_statement_t const *const switchs = &stmt->switchs;
5033                         expression_t       const *const expr    = switchs->expression;
5034
5035                         if (!expression_returns(expr))
5036                                 return;
5037
5038                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
5039                                 long                    const val      = fold_constant_to_int(expr);
5040                                 case_label_statement_t *      defaults = NULL;
5041                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5042                                         if (i->expression == NULL) {
5043                                                 defaults = i;
5044                                                 continue;
5045                                         }
5046
5047                                         if (i->first_case <= val && val <= i->last_case) {
5048                                                 check_reachable((statement_t*)i);
5049                                                 return;
5050                                         }
5051                                 }
5052
5053                                 if (defaults != NULL) {
5054                                         check_reachable((statement_t*)defaults);
5055                                         return;
5056                                 }
5057                         } else {
5058                                 bool has_default = false;
5059                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5060                                         if (i->expression == NULL)
5061                                                 has_default = true;
5062
5063                                         check_reachable((statement_t*)i);
5064                                 }
5065
5066                                 if (has_default)
5067                                         return;
5068                         }
5069
5070                         next = stmt->base.next;
5071                         break;
5072                 }
5073
5074                 case STATEMENT_EXPRESSION: {
5075                         /* Check for noreturn function call */
5076                         expression_t const *const expr = stmt->expression.expression;
5077                         if (!expression_returns(expr))
5078                                 return;
5079
5080                         next = stmt->base.next;
5081                         break;
5082                 }
5083
5084                 case STATEMENT_CONTINUE:
5085                         for (statement_t *parent = stmt;;) {
5086                                 parent = parent->base.parent;
5087                                 if (parent == NULL) /* continue not within loop */
5088                                         return;
5089
5090                                 next = parent;
5091                                 switch (parent->kind) {
5092                                         case STATEMENT_WHILE:    goto continue_while;
5093                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5094                                         case STATEMENT_FOR:      goto continue_for;
5095
5096                                         default: break;
5097                                 }
5098                         }
5099
5100                 case STATEMENT_BREAK:
5101                         for (statement_t *parent = stmt;;) {
5102                                 parent = parent->base.parent;
5103                                 if (parent == NULL) /* break not within loop/switch */
5104                                         return;
5105
5106                                 switch (parent->kind) {
5107                                         case STATEMENT_SWITCH:
5108                                         case STATEMENT_WHILE:
5109                                         case STATEMENT_DO_WHILE:
5110                                         case STATEMENT_FOR:
5111                                                 last = parent;
5112                                                 next = parent->base.next;
5113                                                 goto found_break_parent;
5114
5115                                         default: break;
5116                                 }
5117                         }
5118 found_break_parent:
5119                         break;
5120
5121                 case STATEMENT_GOTO:
5122                         if (stmt->gotos.expression) {
5123                                 if (!expression_returns(stmt->gotos.expression))
5124                                         return;
5125
5126                                 statement_t *parent = stmt->base.parent;
5127                                 if (parent == NULL) /* top level goto */
5128                                         return;
5129                                 next = parent;
5130                         } else {
5131                                 next = stmt->gotos.label->statement;
5132                                 if (next == NULL) /* missing label */
5133                                         return;
5134                         }
5135                         break;
5136
5137                 case STATEMENT_LABEL:
5138                         next = stmt->label.statement;
5139                         break;
5140
5141                 case STATEMENT_CASE_LABEL:
5142                         next = stmt->case_label.statement;
5143                         break;
5144
5145                 case STATEMENT_WHILE: {
5146                         while_statement_t const *const whiles = &stmt->whiles;
5147                         expression_t      const *const cond   = whiles->condition;
5148
5149                         if (!expression_returns(cond))
5150                                 return;
5151
5152                         int const val = determine_truth(cond);
5153
5154                         if (val >= 0)
5155                                 check_reachable(whiles->body);
5156
5157                         if (val > 0)
5158                                 return;
5159
5160                         next = stmt->base.next;
5161                         break;
5162                 }
5163
5164                 case STATEMENT_DO_WHILE:
5165                         next = stmt->do_while.body;
5166                         break;
5167
5168                 case STATEMENT_FOR: {
5169                         for_statement_t *const fors = &stmt->fors;
5170
5171                         if (fors->condition_reachable)
5172                                 return;
5173                         fors->condition_reachable = true;
5174
5175                         expression_t const *const cond = fors->condition;
5176
5177                         int val;
5178                         if (cond == NULL) {
5179                                 val = 1;
5180                         } else if (expression_returns(cond)) {
5181                                 val = determine_truth(cond);
5182                         } else {
5183                                 return;
5184                         }
5185
5186                         if (val >= 0)
5187                                 check_reachable(fors->body);
5188
5189                         if (val > 0)
5190                                 return;
5191
5192                         next = stmt->base.next;
5193                         break;
5194                 }
5195
5196                 case STATEMENT_MS_TRY: {
5197                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5198                         check_reachable(ms_try->try_statement);
5199                         next = ms_try->final_statement;
5200                         break;
5201                 }
5202
5203                 case STATEMENT_LEAVE: {
5204                         statement_t *parent = stmt;
5205                         for (;;) {
5206                                 parent = parent->base.parent;
5207                                 if (parent == NULL) /* __leave not within __try */
5208                                         return;
5209
5210                                 if (parent->kind == STATEMENT_MS_TRY) {
5211                                         last = parent;
5212                                         next = parent->ms_try.final_statement;
5213                                         break;
5214                                 }
5215                         }
5216                         break;
5217                 }
5218
5219                 default:
5220                         panic("invalid statement kind");
5221         }
5222
5223         while (next == NULL) {
5224                 next = last->base.parent;
5225                 if (next == NULL) {
5226                         noreturn_candidate = false;
5227
5228                         type_t *const type = skip_typeref(current_function->base.type);
5229                         assert(is_type_function(type));
5230                         type_t *const ret  = skip_typeref(type->function.return_type);
5231                         if (warning.return_type                    &&
5232                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5233                             is_type_valid(ret)                     &&
5234                             !is_sym_main(current_function->base.base.symbol)) {
5235                                 warningf(&stmt->base.source_position,
5236                                          "control reaches end of non-void function");
5237                         }
5238                         return;
5239                 }
5240
5241                 switch (next->kind) {
5242                         case STATEMENT_INVALID:
5243                         case STATEMENT_EMPTY:
5244                         case STATEMENT_DECLARATION:
5245                         case STATEMENT_EXPRESSION:
5246                         case STATEMENT_ASM:
5247                         case STATEMENT_RETURN:
5248                         case STATEMENT_CONTINUE:
5249                         case STATEMENT_BREAK:
5250                         case STATEMENT_GOTO:
5251                         case STATEMENT_LEAVE:
5252                                 panic("invalid control flow in function");
5253
5254                         case STATEMENT_COMPOUND:
5255                                 if (next->compound.stmt_expr) {
5256                                         reaches_end = true;
5257                                         return;
5258                                 }
5259                                 /* FALLTHROUGH */
5260                         case STATEMENT_IF:
5261                         case STATEMENT_SWITCH:
5262                         case STATEMENT_LABEL:
5263                         case STATEMENT_CASE_LABEL:
5264                                 last = next;
5265                                 next = next->base.next;
5266                                 break;
5267
5268                         case STATEMENT_WHILE: {
5269 continue_while:
5270                                 if (next->base.reachable)
5271                                         return;
5272                                 next->base.reachable = true;
5273
5274                                 while_statement_t const *const whiles = &next->whiles;
5275                                 expression_t      const *const cond   = whiles->condition;
5276
5277                                 if (!expression_returns(cond))
5278                                         return;
5279
5280                                 int const val = determine_truth(cond);
5281
5282                                 if (val >= 0)
5283                                         check_reachable(whiles->body);
5284
5285                                 if (val > 0)
5286                                         return;
5287
5288                                 last = next;
5289                                 next = next->base.next;
5290                                 break;
5291                         }
5292
5293                         case STATEMENT_DO_WHILE: {
5294 continue_do_while:
5295                                 if (next->base.reachable)
5296                                         return;
5297                                 next->base.reachable = true;
5298
5299                                 do_while_statement_t const *const dw   = &next->do_while;
5300                                 expression_t         const *const cond = dw->condition;
5301
5302                                 if (!expression_returns(cond))
5303                                         return;
5304
5305                                 int const val = determine_truth(cond);
5306
5307                                 if (val >= 0)
5308                                         check_reachable(dw->body);
5309
5310                                 if (val > 0)
5311                                         return;
5312
5313                                 last = next;
5314                                 next = next->base.next;
5315                                 break;
5316                         }
5317
5318                         case STATEMENT_FOR: {
5319 continue_for:;
5320                                 for_statement_t *const fors = &next->fors;
5321
5322                                 fors->step_reachable = true;
5323
5324                                 if (fors->condition_reachable)
5325                                         return;
5326                                 fors->condition_reachable = true;
5327
5328                                 expression_t const *const cond = fors->condition;
5329
5330                                 int val;
5331                                 if (cond == NULL) {
5332                                         val = 1;
5333                                 } else if (expression_returns(cond)) {
5334                                         val = determine_truth(cond);
5335                                 } else {
5336                                         return;
5337                                 }
5338
5339                                 if (val >= 0)
5340                                         check_reachable(fors->body);
5341
5342                                 if (val > 0)
5343                                         return;
5344
5345                                 last = next;
5346                                 next = next->base.next;
5347                                 break;
5348                         }
5349
5350                         case STATEMENT_MS_TRY:
5351                                 last = next;
5352                                 next = next->ms_try.final_statement;
5353                                 break;
5354                 }
5355         }
5356
5357         check_reachable(next);
5358 }
5359
5360 static void check_unreachable(statement_t* const stmt, void *const env)
5361 {
5362         (void)env;
5363
5364         switch (stmt->kind) {
5365                 case STATEMENT_DO_WHILE:
5366                         if (!stmt->base.reachable) {
5367                                 expression_t const *const cond = stmt->do_while.condition;
5368                                 if (determine_truth(cond) >= 0) {
5369                                         warningf(&cond->base.source_position,
5370                                                  "condition of do-while-loop is unreachable");
5371                                 }
5372                         }
5373                         return;
5374
5375                 case STATEMENT_FOR: {
5376                         for_statement_t const* const fors = &stmt->fors;
5377
5378                         // if init and step are unreachable, cond is unreachable, too
5379                         if (!stmt->base.reachable && !fors->step_reachable) {
5380                                 warningf(&stmt->base.source_position, "statement is unreachable");
5381                         } else {
5382                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5383                                         warningf(&fors->initialisation->base.source_position,
5384                                                  "initialisation of for-statement is unreachable");
5385                                 }
5386
5387                                 if (!fors->condition_reachable && fors->condition != NULL) {
5388                                         warningf(&fors->condition->base.source_position,
5389                                                  "condition of for-statement is unreachable");
5390                                 }
5391
5392                                 if (!fors->step_reachable && fors->step != NULL) {
5393                                         warningf(&fors->step->base.source_position,
5394                                                  "step of for-statement is unreachable");
5395                                 }
5396                         }
5397                         return;
5398                 }
5399
5400                 case STATEMENT_COMPOUND:
5401                         if (stmt->compound.statements != NULL)
5402                                 return;
5403                         goto warn_unreachable;
5404
5405                 case STATEMENT_DECLARATION: {
5406                         /* Only warn if there is at least one declarator with an initializer.
5407                          * This typically occurs in switch statements. */
5408                         declaration_statement_t const *const decl = &stmt->declaration;
5409                         entity_t                const *      ent  = decl->declarations_begin;
5410                         entity_t                const *const last = decl->declarations_end;
5411                         if (ent != NULL) {
5412                                 for (;; ent = ent->base.next) {
5413                                         if (ent->kind                 == ENTITY_VARIABLE &&
5414                                                         ent->variable.initializer != NULL) {
5415                                                 goto warn_unreachable;
5416                                         }
5417                                         if (ent == last)
5418                                                 return;
5419                                 }
5420                         }
5421                 }
5422
5423                 default:
5424 warn_unreachable:
5425                         if (!stmt->base.reachable)
5426                                 warningf(&stmt->base.source_position, "statement is unreachable");
5427                         return;
5428         }
5429 }
5430
5431 static void parse_external_declaration(void)
5432 {
5433         /* function-definitions and declarations both start with declaration
5434          * specifiers */
5435         add_anchor_token(';');
5436         declaration_specifiers_t specifiers;
5437         parse_declaration_specifiers(&specifiers);
5438         rem_anchor_token(';');
5439
5440         /* must be a declaration */
5441         if (token.type == ';') {
5442                 parse_anonymous_declaration_rest(&specifiers);
5443                 return;
5444         }
5445
5446         add_anchor_token(',');
5447         add_anchor_token('=');
5448         add_anchor_token(';');
5449         add_anchor_token('{');
5450
5451         /* declarator is common to both function-definitions and declarations */
5452         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5453
5454         rem_anchor_token('{');
5455         rem_anchor_token(';');
5456         rem_anchor_token('=');
5457         rem_anchor_token(',');
5458
5459         /* must be a declaration */
5460         switch (token.type) {
5461                 case ',':
5462                 case ';':
5463                 case '=':
5464                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5465                                         DECL_FLAGS_NONE);
5466                         return;
5467         }
5468
5469         /* must be a function definition */
5470         parse_kr_declaration_list(ndeclaration);
5471
5472         if (token.type != '{') {
5473                 parse_error_expected("while parsing function definition", '{', NULL);
5474                 eat_until_matching_token(';');
5475                 return;
5476         }
5477
5478         assert(is_declaration(ndeclaration));
5479         type_t *const orig_type = ndeclaration->declaration.type;
5480         type_t *      type      = skip_typeref(orig_type);
5481
5482         if (!is_type_function(type)) {
5483                 if (is_type_valid(type)) {
5484                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5485                 }
5486                 eat_block();
5487                 return;
5488         }
5489
5490         source_position_t const *const pos = &ndeclaration->base.source_position;
5491         if (is_typeref(orig_type)) {
5492                 /* §6.9.1:2 */
5493                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5494         }
5495
5496         if (warning.aggregate_return &&
5497             is_type_compound(skip_typeref(type->function.return_type))) {
5498                 warningf(pos, "'%N' returns an aggregate", ndeclaration);
5499         }
5500         if (warning.traditional && !type->function.unspecified_parameters) {
5501                 warningf(pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5502         }
5503         if (warning.old_style_definition && type->function.unspecified_parameters) {
5504                 warningf(pos, "old-style definition of '%N'", ndeclaration);
5505         }
5506
5507         /* §6.7.5.3:14 a function definition with () means no
5508          * parameters (and not unspecified parameters) */
5509         if (type->function.unspecified_parameters &&
5510                         type->function.parameters == NULL) {
5511                 type_t *copy                          = duplicate_type(type);
5512                 copy->function.unspecified_parameters = false;
5513                 type                                  = identify_new_type(copy);
5514
5515                 ndeclaration->declaration.type = type;
5516         }
5517
5518         entity_t *const entity = record_entity(ndeclaration, true);
5519         assert(entity->kind == ENTITY_FUNCTION);
5520         assert(ndeclaration->kind == ENTITY_FUNCTION);
5521
5522         function_t *const function = &entity->function;
5523         if (ndeclaration != entity) {
5524                 function->parameters = ndeclaration->function.parameters;
5525         }
5526         assert(is_declaration(entity));
5527         type = skip_typeref(entity->declaration.type);
5528
5529         /* push function parameters and switch scope */
5530         size_t const  top       = environment_top();
5531         scope_t      *old_scope = scope_push(&function->parameters);
5532
5533         entity_t *parameter = function->parameters.entities;
5534         for (; parameter != NULL; parameter = parameter->base.next) {
5535                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5536                         parameter->base.parent_scope = current_scope;
5537                 }
5538                 assert(parameter->base.parent_scope == NULL
5539                                 || parameter->base.parent_scope == current_scope);
5540                 parameter->base.parent_scope = current_scope;
5541                 if (parameter->base.symbol == NULL) {
5542                         errorf(&parameter->base.source_position, "parameter name omitted");
5543                         continue;
5544                 }
5545                 environment_push(parameter);
5546         }
5547
5548         if (function->statement != NULL) {
5549                 parser_error_multiple_definition(entity, HERE);
5550                 eat_block();
5551         } else {
5552                 /* parse function body */
5553                 int         label_stack_top      = label_top();
5554                 function_t *old_current_function = current_function;
5555                 entity_t   *old_current_entity   = current_entity;
5556                 current_function                 = function;
5557                 current_entity                   = entity;
5558                 current_parent                   = NULL;
5559
5560                 goto_first   = NULL;
5561                 goto_anchor  = &goto_first;
5562                 label_first  = NULL;
5563                 label_anchor = &label_first;
5564
5565                 statement_t *const body = parse_compound_statement(false);
5566                 function->statement = body;
5567                 first_err = true;
5568                 check_labels();
5569                 check_declarations();
5570                 if (warning.return_type      ||
5571                     warning.unreachable_code ||
5572                     (warning.missing_noreturn
5573                      && !(function->base.modifiers & DM_NORETURN))) {
5574                         noreturn_candidate = true;
5575                         check_reachable(body);
5576                         if (warning.unreachable_code)
5577                                 walk_statements(body, check_unreachable, NULL);
5578                         if (warning.missing_noreturn &&
5579                             noreturn_candidate       &&
5580                             !(function->base.modifiers & DM_NORETURN)) {
5581                                 source_position_t const *const pos = &body->base.source_position;
5582                                 warningf(pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5583                         }
5584                 }
5585
5586                 assert(current_parent   == NULL);
5587                 assert(current_function == function);
5588                 assert(current_entity   == entity);
5589                 current_entity   = old_current_entity;
5590                 current_function = old_current_function;
5591                 label_pop_to(label_stack_top);
5592         }
5593
5594         assert(current_scope == &function->parameters);
5595         scope_pop(old_scope);
5596         environment_pop_to(top);
5597 }
5598
5599 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5600                                   source_position_t *source_position,
5601                                   const symbol_t *symbol)
5602 {
5603         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5604
5605         type->bitfield.base_type       = base_type;
5606         type->bitfield.size_expression = size;
5607
5608         il_size_t bit_size;
5609         type_t *skipped_type = skip_typeref(base_type);
5610         if (!is_type_integer(skipped_type)) {
5611                 errorf(source_position, "bitfield base type '%T' is not an integer type", base_type);
5612                 bit_size = 0;
5613         } else {
5614                 bit_size = get_type_size(base_type) * 8;
5615         }
5616
5617         if (is_constant_expression(size) == EXPR_CLASS_CONSTANT) {
5618                 long v = fold_constant_to_int(size);
5619                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5620
5621                 if (v < 0) {
5622                         errorf(source_position, "negative width in bit-field '%Y'",
5623                                user_symbol);
5624                 } else if (v == 0 && symbol != NULL) {
5625                         errorf(source_position, "zero width for bit-field '%Y'",
5626                                user_symbol);
5627                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5628                         errorf(source_position, "width of '%Y' exceeds its type",
5629                                user_symbol);
5630                 } else {
5631                         type->bitfield.bit_size = v;
5632                 }
5633         }
5634
5635         return type;
5636 }
5637
5638 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5639 {
5640         entity_t *iter = compound->members.entities;
5641         for (; iter != NULL; iter = iter->base.next) {
5642                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5643                         continue;
5644
5645                 if (iter->base.symbol == symbol) {
5646                         return iter;
5647                 } else if (iter->base.symbol == NULL) {
5648                         /* search in anonymous structs and unions */
5649                         type_t *type = skip_typeref(iter->declaration.type);
5650                         if (is_type_compound(type)) {
5651                                 if (find_compound_entry(type->compound.compound, symbol)
5652                                                 != NULL)
5653                                         return iter;
5654                         }
5655                         continue;
5656                 }
5657         }
5658
5659         return NULL;
5660 }
5661
5662 static void check_deprecated(const source_position_t *source_position,
5663                              const entity_t *entity)
5664 {
5665         if (!warning.deprecated_declarations)
5666                 return;
5667         if (!is_declaration(entity))
5668                 return;
5669         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5670                 return;
5671
5672         source_position_t const *const pos = &entity->base.source_position;
5673         char              const* const msg = get_deprecated_string(entity->declaration.attributes);
5674         if (msg != NULL) {
5675                 warningf(source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, pos, msg);
5676         } else {
5677                 warningf(source_position, "'%N' is deprecated (declared %P)", entity, pos);
5678         }
5679 }
5680
5681
5682 static expression_t *create_select(const source_position_t *pos,
5683                                    expression_t *addr,
5684                                    type_qualifiers_t qualifiers,
5685                                                                    entity_t *entry)
5686 {
5687         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5688
5689         check_deprecated(pos, entry);
5690
5691         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5692         select->select.compound       = addr;
5693         select->select.compound_entry = entry;
5694
5695         type_t *entry_type = entry->declaration.type;
5696         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5697
5698         /* we always do the auto-type conversions; the & and sizeof parser contains
5699          * code to revert this! */
5700         select->base.type = automatic_type_conversion(res_type);
5701         if (res_type->kind == TYPE_BITFIELD) {
5702                 select->base.type = res_type->bitfield.base_type;
5703         }
5704
5705         return select;
5706 }
5707
5708 /**
5709  * Find entry with symbol in compound. Search anonymous structs and unions and
5710  * creates implicit select expressions for them.
5711  * Returns the adress for the innermost compound.
5712  */
5713 static expression_t *find_create_select(const source_position_t *pos,
5714                                         expression_t *addr,
5715                                         type_qualifiers_t qualifiers,
5716                                         compound_t *compound, symbol_t *symbol)
5717 {
5718         entity_t *iter = compound->members.entities;
5719         for (; iter != NULL; iter = iter->base.next) {
5720                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5721                         continue;
5722
5723                 symbol_t *iter_symbol = iter->base.symbol;
5724                 if (iter_symbol == NULL) {
5725                         type_t *type = iter->declaration.type;
5726                         if (type->kind != TYPE_COMPOUND_STRUCT
5727                                         && type->kind != TYPE_COMPOUND_UNION)
5728                                 continue;
5729
5730                         compound_t *sub_compound = type->compound.compound;
5731
5732                         if (find_compound_entry(sub_compound, symbol) == NULL)
5733                                 continue;
5734
5735                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5736                         sub_addr->base.source_position = *pos;
5737                         sub_addr->select.implicit      = true;
5738                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5739                                                   symbol);
5740                 }
5741
5742                 if (iter_symbol == symbol) {
5743                         return create_select(pos, addr, qualifiers, iter);
5744                 }
5745         }
5746
5747         return NULL;
5748 }
5749
5750 static void parse_compound_declarators(compound_t *compound,
5751                 const declaration_specifiers_t *specifiers)
5752 {
5753         do {
5754                 entity_t *entity;
5755
5756                 if (token.type == ':') {
5757                         source_position_t source_position = *HERE;
5758                         next_token();
5759
5760                         type_t *base_type = specifiers->type;
5761                         expression_t *size = parse_constant_expression();
5762
5763                         type_t *type = make_bitfield_type(base_type, size,
5764                                         &source_position, NULL);
5765
5766                         attribute_t  *attributes = parse_attributes(NULL);
5767                         attribute_t **anchor     = &attributes;
5768                         while (*anchor != NULL)
5769                                 anchor = &(*anchor)->next;
5770                         *anchor = specifiers->attributes;
5771
5772                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL);
5773                         entity->base.source_position               = source_position;
5774                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5775                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5776                         entity->declaration.type                   = type;
5777                         entity->declaration.attributes             = attributes;
5778
5779                         if (attributes != NULL) {
5780                                 handle_entity_attributes(attributes, entity);
5781                         }
5782                         append_entity(&compound->members, entity);
5783                 } else {
5784                         entity = parse_declarator(specifiers,
5785                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5786                         source_position_t const *const pos = &entity->base.source_position;
5787                         if (entity->kind == ENTITY_TYPEDEF) {
5788                                 errorf(pos, "typedef not allowed as compound member");
5789                         } else {
5790                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5791
5792                                 /* make sure we don't define a symbol multiple times */
5793                                 symbol_t *symbol = entity->base.symbol;
5794                                 if (symbol != NULL) {
5795                                         entity_t *prev = find_compound_entry(compound, symbol);
5796                                         if (prev != NULL) {
5797                                                 source_position_t const *const ppos = &prev->base.source_position;
5798                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5799                                         }
5800                                 }
5801
5802                                 if (token.type == ':') {
5803                                         source_position_t source_position = *HERE;
5804                                         next_token();
5805                                         expression_t *size = parse_constant_expression();
5806
5807                                         type_t *type          = entity->declaration.type;
5808                                         type_t *bitfield_type = make_bitfield_type(type, size,
5809                                                         &source_position, entity->base.symbol);
5810
5811                                         attribute_t *attributes = parse_attributes(NULL);
5812                                         entity->declaration.type = bitfield_type;
5813                                         handle_entity_attributes(attributes, entity);
5814                                 } else {
5815                                         type_t *orig_type = entity->declaration.type;
5816                                         type_t *type      = skip_typeref(orig_type);
5817                                         if (is_type_function(type)) {
5818                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5819                                         } else if (is_type_incomplete(type)) {
5820                                                 /* §6.7.2.1:16 flexible array member */
5821                                                 if (!is_type_array(type)       ||
5822                                                                 token.type          != ';' ||
5823                                                                 look_ahead(1)->type != '}') {
5824                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5825                                                 }
5826                                         }
5827                                 }
5828
5829                                 append_entity(&compound->members, entity);
5830                         }
5831                 }
5832         } while (next_if(','));
5833         expect(';', end_error);
5834
5835 end_error:
5836         anonymous_entity = NULL;
5837 }
5838
5839 static void parse_compound_type_entries(compound_t *compound)
5840 {
5841         eat('{');
5842         add_anchor_token('}');
5843
5844         while (token.type != '}') {
5845                 if (token.type == T_EOF) {
5846                         errorf(HERE, "EOF while parsing struct");
5847                         break;
5848                 }
5849                 declaration_specifiers_t specifiers;
5850                 parse_declaration_specifiers(&specifiers);
5851                 parse_compound_declarators(compound, &specifiers);
5852         }
5853         rem_anchor_token('}');
5854         next_token();
5855
5856         /* §6.7.2.1:7 */
5857         compound->complete = true;
5858 }
5859
5860 static type_t *parse_typename(void)
5861 {
5862         declaration_specifiers_t specifiers;
5863         parse_declaration_specifiers(&specifiers);
5864         if (specifiers.storage_class != STORAGE_CLASS_NONE
5865                         || specifiers.thread_local) {
5866                 /* TODO: improve error message, user does probably not know what a
5867                  * storage class is...
5868                  */
5869                 errorf(&specifiers.source_position, "typename must not have a storage class");
5870         }
5871
5872         type_t *result = parse_abstract_declarator(specifiers.type);
5873
5874         return result;
5875 }
5876
5877
5878
5879
5880 typedef expression_t* (*parse_expression_function)(void);
5881 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5882
5883 typedef struct expression_parser_function_t expression_parser_function_t;
5884 struct expression_parser_function_t {
5885         parse_expression_function        parser;
5886         precedence_t                     infix_precedence;
5887         parse_expression_infix_function  infix_parser;
5888 };
5889
5890 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5891
5892 /**
5893  * Prints an error message if an expression was expected but not read
5894  */
5895 static expression_t *expected_expression_error(void)
5896 {
5897         /* skip the error message if the error token was read */
5898         if (token.type != T_ERROR) {
5899                 errorf(HERE, "expected expression, got token %K", &token);
5900         }
5901         next_token();
5902
5903         return create_invalid_expression();
5904 }
5905
5906 static type_t *get_string_type(void)
5907 {
5908         return warning.write_strings ? type_const_char_ptr : type_char_ptr;
5909 }
5910
5911 static type_t *get_wide_string_type(void)
5912 {
5913         return warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5914 }
5915
5916 /**
5917  * Parse a string constant.
5918  */
5919 static expression_t *parse_string_literal(void)
5920 {
5921         source_position_t begin   = token.source_position;
5922         string_t          res     = token.literal;
5923         bool              is_wide = (token.type == T_WIDE_STRING_LITERAL);
5924
5925         next_token();
5926         while (token.type == T_STRING_LITERAL
5927                         || token.type == T_WIDE_STRING_LITERAL) {
5928                 warn_string_concat(&token.source_position);
5929                 res = concat_strings(&res, &token.literal);
5930                 next_token();
5931                 is_wide |= token.type == T_WIDE_STRING_LITERAL;
5932         }
5933
5934         expression_t *literal;
5935         if (is_wide) {
5936                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5937                 literal->base.type = get_wide_string_type();
5938         } else {
5939                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5940                 literal->base.type = get_string_type();
5941         }
5942         literal->base.source_position = begin;
5943         literal->literal.value        = res;
5944
5945         return literal;
5946 }
5947
5948 /**
5949  * Parse a boolean constant.
5950  */
5951 static expression_t *parse_boolean_literal(bool value)
5952 {
5953         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5954         literal->base.source_position = token.source_position;
5955         literal->base.type            = type_bool;
5956         literal->literal.value.begin  = value ? "true" : "false";
5957         literal->literal.value.size   = value ? 4 : 5;
5958
5959         next_token();
5960         return literal;
5961 }
5962
5963 static void warn_traditional_suffix(void)
5964 {
5965         if (!warning.traditional)
5966                 return;
5967         warningf(&token.source_position, "traditional C rejects the '%Y' suffix",
5968                  token.symbol);
5969 }
5970
5971 static void check_integer_suffix(void)
5972 {
5973         symbol_t *suffix = token.symbol;
5974         if (suffix == NULL)
5975                 return;
5976
5977         bool not_traditional = false;
5978         const char *c = suffix->string;
5979         if (*c == 'l' || *c == 'L') {
5980                 ++c;
5981                 if (*c == *(c-1)) {
5982                         not_traditional = true;
5983                         ++c;
5984                         if (*c == 'u' || *c == 'U') {
5985                                 ++c;
5986                         }
5987                 } else if (*c == 'u' || *c == 'U') {
5988                         not_traditional = true;
5989                         ++c;
5990                 }
5991         } else if (*c == 'u' || *c == 'U') {
5992                 not_traditional = true;
5993                 ++c;
5994                 if (*c == 'l' || *c == 'L') {
5995                         ++c;
5996                         if (*c == *(c-1)) {
5997                                 ++c;
5998                         }
5999                 }
6000         }
6001         if (*c != '\0') {
6002                 errorf(&token.source_position,
6003                        "invalid suffix '%s' on integer constant", suffix->string);
6004         } else if (not_traditional) {
6005                 warn_traditional_suffix();
6006         }
6007 }
6008
6009 static type_t *check_floatingpoint_suffix(void)
6010 {
6011         symbol_t *suffix = token.symbol;
6012         type_t   *type   = type_double;
6013         if (suffix == NULL)
6014                 return type;
6015
6016         bool not_traditional = false;
6017         const char *c = suffix->string;
6018         if (*c == 'f' || *c == 'F') {
6019                 ++c;
6020                 type = type_float;
6021         } else if (*c == 'l' || *c == 'L') {
6022                 ++c;
6023                 type = type_long_double;
6024         }
6025         if (*c != '\0') {
6026                 errorf(&token.source_position,
6027                        "invalid suffix '%s' on floatingpoint constant", suffix->string);
6028         } else if (not_traditional) {
6029                 warn_traditional_suffix();
6030         }
6031
6032         return type;
6033 }
6034
6035 /**
6036  * Parse an integer constant.
6037  */
6038 static expression_t *parse_number_literal(void)
6039 {
6040         expression_kind_t  kind;
6041         type_t            *type;
6042
6043         switch (token.type) {
6044         case T_INTEGER:
6045                 kind = EXPR_LITERAL_INTEGER;
6046                 check_integer_suffix();
6047                 type = type_int;
6048                 break;
6049         case T_INTEGER_OCTAL:
6050                 kind = EXPR_LITERAL_INTEGER_OCTAL;
6051                 check_integer_suffix();
6052                 type = type_int;
6053                 break;
6054         case T_INTEGER_HEXADECIMAL:
6055                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
6056                 check_integer_suffix();
6057                 type = type_int;
6058                 break;
6059         case T_FLOATINGPOINT:
6060                 kind = EXPR_LITERAL_FLOATINGPOINT;
6061                 type = check_floatingpoint_suffix();
6062                 break;
6063         case T_FLOATINGPOINT_HEXADECIMAL:
6064                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
6065                 type = check_floatingpoint_suffix();
6066                 break;
6067         default:
6068                 panic("unexpected token type in parse_number_literal");
6069         }
6070
6071         expression_t *literal = allocate_expression_zero(kind);
6072         literal->base.source_position = token.source_position;
6073         literal->base.type            = type;
6074         literal->literal.value        = token.literal;
6075         literal->literal.suffix       = token.symbol;
6076         next_token();
6077
6078         /* integer type depends on the size of the number and the size
6079          * representable by the types. The backend/codegeneration has to determine
6080          * that
6081          */
6082         determine_literal_type(&literal->literal);
6083         return literal;
6084 }
6085
6086 /**
6087  * Parse a character constant.
6088  */
6089 static expression_t *parse_character_constant(void)
6090 {
6091         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
6092         literal->base.source_position = token.source_position;
6093         literal->base.type            = c_mode & _CXX ? type_char : type_int;
6094         literal->literal.value        = token.literal;
6095
6096         size_t len = literal->literal.value.size;
6097         if (len > 1) {
6098                 if (!GNU_MODE && !(c_mode & _C99)) {
6099                         errorf(HERE, "more than 1 character in character constant");
6100                 } else if (warning.multichar) {
6101                         literal->base.type = type_int;
6102                         warningf(HERE, "multi-character character constant");
6103                 }
6104         }
6105
6106         next_token();
6107         return literal;
6108 }
6109
6110 /**
6111  * Parse a wide character constant.
6112  */
6113 static expression_t *parse_wide_character_constant(void)
6114 {
6115         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6116         literal->base.source_position = token.source_position;
6117         literal->base.type            = type_int;
6118         literal->literal.value        = token.literal;
6119
6120         size_t len = wstrlen(&literal->literal.value);
6121         if (len > 1) {
6122                 warningf(HERE, "multi-character character constant");
6123         }
6124
6125         next_token();
6126         return literal;
6127 }
6128
6129 static entity_t *create_implicit_function(symbol_t *symbol,
6130                 const source_position_t *source_position)
6131 {
6132         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6133         ntype->function.return_type            = type_int;
6134         ntype->function.unspecified_parameters = true;
6135         ntype->function.linkage                = LINKAGE_C;
6136         type_t *type                           = identify_new_type(ntype);
6137
6138         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol);
6139         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6140         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6141         entity->declaration.type                   = type;
6142         entity->declaration.implicit               = true;
6143         entity->base.source_position               = *source_position;
6144
6145         if (current_scope != NULL)
6146                 record_entity(entity, false);
6147
6148         return entity;
6149 }
6150
6151 /**
6152  * Performs automatic type cast as described in §6.3.2.1.
6153  *
6154  * @param orig_type  the original type
6155  */
6156 static type_t *automatic_type_conversion(type_t *orig_type)
6157 {
6158         type_t *type = skip_typeref(orig_type);
6159         if (is_type_array(type)) {
6160                 array_type_t *array_type   = &type->array;
6161                 type_t       *element_type = array_type->element_type;
6162                 unsigned      qualifiers   = array_type->base.qualifiers;
6163
6164                 return make_pointer_type(element_type, qualifiers);
6165         }
6166
6167         if (is_type_function(type)) {
6168                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6169         }
6170
6171         return orig_type;
6172 }
6173
6174 /**
6175  * reverts the automatic casts of array to pointer types and function
6176  * to function-pointer types as defined §6.3.2.1
6177  */
6178 type_t *revert_automatic_type_conversion(const expression_t *expression)
6179 {
6180         switch (expression->kind) {
6181         case EXPR_REFERENCE: {
6182                 entity_t *entity = expression->reference.entity;
6183                 if (is_declaration(entity)) {
6184                         return entity->declaration.type;
6185                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6186                         return entity->enum_value.enum_type;
6187                 } else {
6188                         panic("no declaration or enum in reference");
6189                 }
6190         }
6191
6192         case EXPR_SELECT: {
6193                 entity_t *entity = expression->select.compound_entry;
6194                 assert(is_declaration(entity));
6195                 type_t   *type   = entity->declaration.type;
6196                 return get_qualified_type(type,
6197                                 expression->base.type->base.qualifiers);
6198         }
6199
6200         case EXPR_UNARY_DEREFERENCE: {
6201                 const expression_t *const value = expression->unary.value;
6202                 type_t             *const type  = skip_typeref(value->base.type);
6203                 if (!is_type_pointer(type))
6204                         return type_error_type;
6205                 return type->pointer.points_to;
6206         }
6207
6208         case EXPR_ARRAY_ACCESS: {
6209                 const expression_t *array_ref = expression->array_access.array_ref;
6210                 type_t             *type_left = skip_typeref(array_ref->base.type);
6211                 if (!is_type_pointer(type_left))
6212                         return type_error_type;
6213                 return type_left->pointer.points_to;
6214         }
6215
6216         case EXPR_STRING_LITERAL: {
6217                 size_t size = expression->string_literal.value.size;
6218                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6219         }
6220
6221         case EXPR_WIDE_STRING_LITERAL: {
6222                 size_t size = wstrlen(&expression->string_literal.value);
6223                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6224         }
6225
6226         case EXPR_COMPOUND_LITERAL:
6227                 return expression->compound_literal.type;
6228
6229         default:
6230                 break;
6231         }
6232         return expression->base.type;
6233 }
6234
6235 /**
6236  * Find an entity matching a symbol in a scope.
6237  * Uses current scope if scope is NULL
6238  */
6239 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6240                                namespace_tag_t namespc)
6241 {
6242         if (scope == NULL) {
6243                 return get_entity(symbol, namespc);
6244         }
6245
6246         /* we should optimize here, if scope grows above a certain size we should
6247            construct a hashmap here... */
6248         entity_t *entity = scope->entities;
6249         for ( ; entity != NULL; entity = entity->base.next) {
6250                 if (entity->base.symbol == symbol
6251                     && (namespace_tag_t)entity->base.namespc == namespc)
6252                         break;
6253         }
6254
6255         return entity;
6256 }
6257
6258 static entity_t *parse_qualified_identifier(void)
6259 {
6260         /* namespace containing the symbol */
6261         symbol_t          *symbol;
6262         source_position_t  pos;
6263         const scope_t     *lookup_scope = NULL;
6264
6265         if (next_if(T_COLONCOLON))
6266                 lookup_scope = &unit->scope;
6267
6268         entity_t *entity;
6269         while (true) {
6270                 if (token.type != T_IDENTIFIER) {
6271                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6272                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6273                 }
6274                 symbol = token.symbol;
6275                 pos    = *HERE;
6276                 next_token();
6277
6278                 /* lookup entity */
6279                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6280
6281                 if (!next_if(T_COLONCOLON))
6282                         break;
6283
6284                 switch (entity->kind) {
6285                 case ENTITY_NAMESPACE:
6286                         lookup_scope = &entity->namespacee.members;
6287                         break;
6288                 case ENTITY_STRUCT:
6289                 case ENTITY_UNION:
6290                 case ENTITY_CLASS:
6291                         lookup_scope = &entity->compound.members;
6292                         break;
6293                 default:
6294                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6295                                symbol, get_entity_kind_name(entity->kind));
6296
6297                         /* skip further qualifications */
6298                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6299
6300                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6301                 }
6302         }
6303
6304         if (entity == NULL) {
6305                 if (!strict_mode && token.type == '(') {
6306                         /* an implicitly declared function */
6307                         if (warning.error_implicit_function_declaration) {
6308                                 errorf(&pos, "implicit declaration of function '%Y'", symbol);
6309                         } else if (warning.implicit_function_declaration) {
6310                                 warningf(&pos, "implicit declaration of function '%Y'", symbol);
6311                         }
6312
6313                         entity = create_implicit_function(symbol, &pos);
6314                 } else {
6315                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6316                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6317                 }
6318         }
6319
6320         return entity;
6321 }
6322
6323 static expression_t *parse_reference(void)
6324 {
6325         source_position_t const pos    = token.source_position;
6326         entity_t         *const entity = parse_qualified_identifier();
6327
6328         type_t *orig_type;
6329         if (is_declaration(entity)) {
6330                 orig_type = entity->declaration.type;
6331         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6332                 orig_type = entity->enum_value.enum_type;
6333         } else {
6334                 panic("expected declaration or enum value in reference");
6335         }
6336
6337         /* we always do the auto-type conversions; the & and sizeof parser contains
6338          * code to revert this! */
6339         type_t *type = automatic_type_conversion(orig_type);
6340
6341         expression_kind_t kind = EXPR_REFERENCE;
6342         if (entity->kind == ENTITY_ENUM_VALUE)
6343                 kind = EXPR_REFERENCE_ENUM_VALUE;
6344
6345         expression_t *expression         = allocate_expression_zero(kind);
6346         expression->base.source_position = pos;
6347         expression->base.type            = type;
6348         expression->reference.entity     = entity;
6349
6350         /* this declaration is used */
6351         if (is_declaration(entity)) {
6352                 entity->declaration.used = true;
6353         }
6354
6355         if (entity->base.parent_scope != file_scope
6356                 && (current_function != NULL
6357                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6358                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6359                 if (entity->kind == ENTITY_VARIABLE) {
6360                         /* access of a variable from an outer function */
6361                         entity->variable.address_taken = true;
6362                 } else if (entity->kind == ENTITY_PARAMETER) {
6363                         entity->parameter.address_taken = true;
6364                 }
6365                 current_function->need_closure = true;
6366         }
6367
6368         check_deprecated(&pos, entity);
6369
6370         if (warning.init_self && entity == current_init_decl && !in_type_prop
6371             && entity->kind == ENTITY_VARIABLE) {
6372                 current_init_decl = NULL;
6373                 warningf(&pos, "variable '%#N' is initialized by itself", entity);
6374         }
6375
6376         return expression;
6377 }
6378
6379 static bool semantic_cast(expression_t *cast)
6380 {
6381         expression_t            *expression      = cast->unary.value;
6382         type_t                  *orig_dest_type  = cast->base.type;
6383         type_t                  *orig_type_right = expression->base.type;
6384         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6385         type_t            const *src_type        = skip_typeref(orig_type_right);
6386         source_position_t const *pos             = &cast->base.source_position;
6387
6388         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6389         if (dst_type == type_void)
6390                 return true;
6391
6392         /* only integer and pointer can be casted to pointer */
6393         if (is_type_pointer(dst_type)  &&
6394             !is_type_pointer(src_type) &&
6395             !is_type_integer(src_type) &&
6396             is_type_valid(src_type)) {
6397                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6398                 return false;
6399         }
6400
6401         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6402                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6403                 return false;
6404         }
6405
6406         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6407                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6408                 return false;
6409         }
6410
6411         if (warning.cast_qual &&
6412             is_type_pointer(src_type) &&
6413             is_type_pointer(dst_type)) {
6414                 type_t *src = skip_typeref(src_type->pointer.points_to);
6415                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6416                 unsigned missing_qualifiers =
6417                         src->base.qualifiers & ~dst->base.qualifiers;
6418                 if (missing_qualifiers != 0) {
6419                         warningf(pos,
6420                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6421                                  missing_qualifiers, orig_type_right);
6422                 }
6423         }
6424         return true;
6425 }
6426
6427 static expression_t *parse_compound_literal(type_t *type)
6428 {
6429         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6430
6431         parse_initializer_env_t env;
6432         env.type             = type;
6433         env.entity           = NULL;
6434         env.must_be_constant = false;
6435         initializer_t *initializer = parse_initializer(&env);
6436         type = env.type;
6437
6438         expression->compound_literal.initializer = initializer;
6439         expression->compound_literal.type        = type;
6440         expression->base.type                    = automatic_type_conversion(type);
6441
6442         return expression;
6443 }
6444
6445 /**
6446  * Parse a cast expression.
6447  */
6448 static expression_t *parse_cast(void)
6449 {
6450         source_position_t source_position = token.source_position;
6451
6452         eat('(');
6453         add_anchor_token(')');
6454
6455         type_t *type = parse_typename();
6456
6457         rem_anchor_token(')');
6458         expect(')', end_error);
6459
6460         if (token.type == '{') {
6461                 return parse_compound_literal(type);
6462         }
6463
6464         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6465         cast->base.source_position = source_position;
6466
6467         expression_t *value = parse_subexpression(PREC_CAST);
6468         cast->base.type   = type;
6469         cast->unary.value = value;
6470
6471         if (! semantic_cast(cast)) {
6472                 /* TODO: record the error in the AST. else it is impossible to detect it */
6473         }
6474
6475         return cast;
6476 end_error:
6477         return create_invalid_expression();
6478 }
6479
6480 /**
6481  * Parse a statement expression.
6482  */
6483 static expression_t *parse_statement_expression(void)
6484 {
6485         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6486
6487         eat('(');
6488         add_anchor_token(')');
6489
6490         statement_t *statement          = parse_compound_statement(true);
6491         statement->compound.stmt_expr   = true;
6492         expression->statement.statement = statement;
6493
6494         /* find last statement and use its type */
6495         type_t *type = type_void;
6496         const statement_t *stmt = statement->compound.statements;
6497         if (stmt != NULL) {
6498                 while (stmt->base.next != NULL)
6499                         stmt = stmt->base.next;
6500
6501                 if (stmt->kind == STATEMENT_EXPRESSION) {
6502                         type = stmt->expression.expression->base.type;
6503                 }
6504         } else if (warning.other) {
6505                 warningf(&expression->base.source_position, "empty statement expression ({})");
6506         }
6507         expression->base.type = type;
6508
6509         rem_anchor_token(')');
6510         expect(')', end_error);
6511
6512 end_error:
6513         return expression;
6514 }
6515
6516 /**
6517  * Parse a parenthesized expression.
6518  */
6519 static expression_t *parse_parenthesized_expression(void)
6520 {
6521         token_t const* const la1 = look_ahead(1);
6522         switch (la1->type) {
6523         case '{':
6524                 /* gcc extension: a statement expression */
6525                 return parse_statement_expression();
6526
6527         case T_IDENTIFIER:
6528                 if (is_typedef_symbol(la1->symbol)) {
6529         DECLARATION_START
6530                         return parse_cast();
6531                 }
6532         }
6533
6534         eat('(');
6535         add_anchor_token(')');
6536         expression_t *result = parse_expression();
6537         result->base.parenthesized = true;
6538         rem_anchor_token(')');
6539         expect(')', end_error);
6540
6541 end_error:
6542         return result;
6543 }
6544
6545 static expression_t *parse_function_keyword(void)
6546 {
6547         /* TODO */
6548
6549         if (current_function == NULL) {
6550                 errorf(HERE, "'__func__' used outside of a function");
6551         }
6552
6553         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6554         expression->base.type     = type_char_ptr;
6555         expression->funcname.kind = FUNCNAME_FUNCTION;
6556
6557         next_token();
6558
6559         return expression;
6560 }
6561
6562 static expression_t *parse_pretty_function_keyword(void)
6563 {
6564         if (current_function == NULL) {
6565                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6566         }
6567
6568         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6569         expression->base.type     = type_char_ptr;
6570         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6571
6572         eat(T___PRETTY_FUNCTION__);
6573
6574         return expression;
6575 }
6576
6577 static expression_t *parse_funcsig_keyword(void)
6578 {
6579         if (current_function == NULL) {
6580                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6581         }
6582
6583         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6584         expression->base.type     = type_char_ptr;
6585         expression->funcname.kind = FUNCNAME_FUNCSIG;
6586
6587         eat(T___FUNCSIG__);
6588
6589         return expression;
6590 }
6591
6592 static expression_t *parse_funcdname_keyword(void)
6593 {
6594         if (current_function == NULL) {
6595                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6596         }
6597
6598         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6599         expression->base.type     = type_char_ptr;
6600         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6601
6602         eat(T___FUNCDNAME__);
6603
6604         return expression;
6605 }
6606
6607 static designator_t *parse_designator(void)
6608 {
6609         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6610         result->source_position = *HERE;
6611
6612         if (token.type != T_IDENTIFIER) {
6613                 parse_error_expected("while parsing member designator",
6614                                      T_IDENTIFIER, NULL);
6615                 return NULL;
6616         }
6617         result->symbol = token.symbol;
6618         next_token();
6619
6620         designator_t *last_designator = result;
6621         while (true) {
6622                 if (next_if('.')) {
6623                         if (token.type != T_IDENTIFIER) {
6624                                 parse_error_expected("while parsing member designator",
6625                                                      T_IDENTIFIER, NULL);
6626                                 return NULL;
6627                         }
6628                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6629                         designator->source_position = *HERE;
6630                         designator->symbol          = token.symbol;
6631                         next_token();
6632
6633                         last_designator->next = designator;
6634                         last_designator       = designator;
6635                         continue;
6636                 }
6637                 if (next_if('[')) {
6638                         add_anchor_token(']');
6639                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6640                         designator->source_position = *HERE;
6641                         designator->array_index     = parse_expression();
6642                         rem_anchor_token(']');
6643                         expect(']', end_error);
6644                         if (designator->array_index == NULL) {
6645                                 return NULL;
6646                         }
6647
6648                         last_designator->next = designator;
6649                         last_designator       = designator;
6650                         continue;
6651                 }
6652                 break;
6653         }
6654
6655         return result;
6656 end_error:
6657         return NULL;
6658 }
6659
6660 /**
6661  * Parse the __builtin_offsetof() expression.
6662  */
6663 static expression_t *parse_offsetof(void)
6664 {
6665         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6666         expression->base.type    = type_size_t;
6667
6668         eat(T___builtin_offsetof);
6669
6670         expect('(', end_error);
6671         add_anchor_token(',');
6672         type_t *type = parse_typename();
6673         rem_anchor_token(',');
6674         expect(',', end_error);
6675         add_anchor_token(')');
6676         designator_t *designator = parse_designator();
6677         rem_anchor_token(')');
6678         expect(')', end_error);
6679
6680         expression->offsetofe.type       = type;
6681         expression->offsetofe.designator = designator;
6682
6683         type_path_t path;
6684         memset(&path, 0, sizeof(path));
6685         path.top_type = type;
6686         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6687
6688         descend_into_subtype(&path);
6689
6690         if (!walk_designator(&path, designator, true)) {
6691                 return create_invalid_expression();
6692         }
6693
6694         DEL_ARR_F(path.path);
6695
6696         return expression;
6697 end_error:
6698         return create_invalid_expression();
6699 }
6700
6701 /**
6702  * Parses a _builtin_va_start() expression.
6703  */
6704 static expression_t *parse_va_start(void)
6705 {
6706         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6707
6708         eat(T___builtin_va_start);
6709
6710         expect('(', end_error);
6711         add_anchor_token(',');
6712         expression->va_starte.ap = parse_assignment_expression();
6713         rem_anchor_token(',');
6714         expect(',', end_error);
6715         expression_t *const expr = parse_assignment_expression();
6716         if (expr->kind == EXPR_REFERENCE) {
6717                 entity_t *const entity = expr->reference.entity;
6718                 if (!current_function->base.type->function.variadic) {
6719                         errorf(&expr->base.source_position,
6720                                         "'va_start' used in non-variadic function");
6721                 } else if (entity->base.parent_scope != &current_function->parameters ||
6722                                 entity->base.next != NULL ||
6723                                 entity->kind != ENTITY_PARAMETER) {
6724                         errorf(&expr->base.source_position,
6725                                "second argument of 'va_start' must be last parameter of the current function");
6726                 } else {
6727                         expression->va_starte.parameter = &entity->variable;
6728                 }
6729                 expect(')', end_error);
6730                 return expression;
6731         }
6732         expect(')', end_error);
6733 end_error:
6734         return create_invalid_expression();
6735 }
6736
6737 /**
6738  * Parses a __builtin_va_arg() expression.
6739  */
6740 static expression_t *parse_va_arg(void)
6741 {
6742         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6743
6744         eat(T___builtin_va_arg);
6745
6746         expect('(', end_error);
6747         call_argument_t ap;
6748         ap.expression = parse_assignment_expression();
6749         expression->va_arge.ap = ap.expression;
6750         check_call_argument(type_valist, &ap, 1);
6751
6752         expect(',', end_error);
6753         expression->base.type = parse_typename();
6754         expect(')', end_error);
6755
6756         return expression;
6757 end_error:
6758         return create_invalid_expression();
6759 }
6760
6761 /**
6762  * Parses a __builtin_va_copy() expression.
6763  */
6764 static expression_t *parse_va_copy(void)
6765 {
6766         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6767
6768         eat(T___builtin_va_copy);
6769
6770         expect('(', end_error);
6771         expression_t *dst = parse_assignment_expression();
6772         assign_error_t error = semantic_assign(type_valist, dst);
6773         report_assign_error(error, type_valist, dst, "call argument 1",
6774                             &dst->base.source_position);
6775         expression->va_copye.dst = dst;
6776
6777         expect(',', end_error);
6778
6779         call_argument_t src;
6780         src.expression = parse_assignment_expression();
6781         check_call_argument(type_valist, &src, 2);
6782         expression->va_copye.src = src.expression;
6783         expect(')', end_error);
6784
6785         return expression;
6786 end_error:
6787         return create_invalid_expression();
6788 }
6789
6790 /**
6791  * Parses a __builtin_constant_p() expression.
6792  */
6793 static expression_t *parse_builtin_constant(void)
6794 {
6795         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6796
6797         eat(T___builtin_constant_p);
6798
6799         expect('(', end_error);
6800         add_anchor_token(')');
6801         expression->builtin_constant.value = parse_assignment_expression();
6802         rem_anchor_token(')');
6803         expect(')', end_error);
6804         expression->base.type = type_int;
6805
6806         return expression;
6807 end_error:
6808         return create_invalid_expression();
6809 }
6810
6811 /**
6812  * Parses a __builtin_types_compatible_p() expression.
6813  */
6814 static expression_t *parse_builtin_types_compatible(void)
6815 {
6816         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6817
6818         eat(T___builtin_types_compatible_p);
6819
6820         expect('(', end_error);
6821         add_anchor_token(')');
6822         add_anchor_token(',');
6823         expression->builtin_types_compatible.left = parse_typename();
6824         rem_anchor_token(',');
6825         expect(',', end_error);
6826         expression->builtin_types_compatible.right = parse_typename();
6827         rem_anchor_token(')');
6828         expect(')', end_error);
6829         expression->base.type = type_int;
6830
6831         return expression;
6832 end_error:
6833         return create_invalid_expression();
6834 }
6835
6836 /**
6837  * Parses a __builtin_is_*() compare expression.
6838  */
6839 static expression_t *parse_compare_builtin(void)
6840 {
6841         expression_t *expression;
6842
6843         switch (token.type) {
6844         case T___builtin_isgreater:
6845                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6846                 break;
6847         case T___builtin_isgreaterequal:
6848                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6849                 break;
6850         case T___builtin_isless:
6851                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6852                 break;
6853         case T___builtin_islessequal:
6854                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6855                 break;
6856         case T___builtin_islessgreater:
6857                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6858                 break;
6859         case T___builtin_isunordered:
6860                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6861                 break;
6862         default:
6863                 internal_errorf(HERE, "invalid compare builtin found");
6864         }
6865         expression->base.source_position = *HERE;
6866         next_token();
6867
6868         expect('(', end_error);
6869         expression->binary.left = parse_assignment_expression();
6870         expect(',', end_error);
6871         expression->binary.right = parse_assignment_expression();
6872         expect(')', end_error);
6873
6874         type_t *const orig_type_left  = expression->binary.left->base.type;
6875         type_t *const orig_type_right = expression->binary.right->base.type;
6876
6877         type_t *const type_left  = skip_typeref(orig_type_left);
6878         type_t *const type_right = skip_typeref(orig_type_right);
6879         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6880                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6881                         type_error_incompatible("invalid operands in comparison",
6882                                 &expression->base.source_position, orig_type_left, orig_type_right);
6883                 }
6884         } else {
6885                 semantic_comparison(&expression->binary);
6886         }
6887
6888         return expression;
6889 end_error:
6890         return create_invalid_expression();
6891 }
6892
6893 /**
6894  * Parses a MS assume() expression.
6895  */
6896 static expression_t *parse_assume(void)
6897 {
6898         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6899
6900         eat(T__assume);
6901
6902         expect('(', end_error);
6903         add_anchor_token(')');
6904         expression->unary.value = parse_assignment_expression();
6905         rem_anchor_token(')');
6906         expect(')', end_error);
6907
6908         expression->base.type = type_void;
6909         return expression;
6910 end_error:
6911         return create_invalid_expression();
6912 }
6913
6914 /**
6915  * Return the label for the current symbol or create a new one.
6916  */
6917 static label_t *get_label(void)
6918 {
6919         assert(token.type == T_IDENTIFIER);
6920         assert(current_function != NULL);
6921
6922         entity_t *label = get_entity(token.symbol, NAMESPACE_LABEL);
6923         /* If we find a local label, we already created the declaration. */
6924         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6925                 if (label->base.parent_scope != current_scope) {
6926                         assert(label->base.parent_scope->depth < current_scope->depth);
6927                         current_function->goto_to_outer = true;
6928                 }
6929         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6930                 /* There is no matching label in the same function, so create a new one. */
6931                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.symbol);
6932                 label_push(label);
6933         }
6934
6935         eat(T_IDENTIFIER);
6936         return &label->label;
6937 }
6938
6939 /**
6940  * Parses a GNU && label address expression.
6941  */
6942 static expression_t *parse_label_address(void)
6943 {
6944         source_position_t source_position = token.source_position;
6945         eat(T_ANDAND);
6946         if (token.type != T_IDENTIFIER) {
6947                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6948                 return create_invalid_expression();
6949         }
6950
6951         label_t *const label = get_label();
6952         label->used          = true;
6953         label->address_taken = true;
6954
6955         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6956         expression->base.source_position = source_position;
6957
6958         /* label address is treated as a void pointer */
6959         expression->base.type           = type_void_ptr;
6960         expression->label_address.label = label;
6961         return expression;
6962 }
6963
6964 /**
6965  * Parse a microsoft __noop expression.
6966  */
6967 static expression_t *parse_noop_expression(void)
6968 {
6969         /* the result is a (int)0 */
6970         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6971         literal->base.type            = type_int;
6972         literal->base.source_position = token.source_position;
6973         literal->literal.value.begin  = "__noop";
6974         literal->literal.value.size   = 6;
6975
6976         eat(T___noop);
6977
6978         if (token.type == '(') {
6979                 /* parse arguments */
6980                 eat('(');
6981                 add_anchor_token(')');
6982                 add_anchor_token(',');
6983
6984                 if (token.type != ')') do {
6985                         (void)parse_assignment_expression();
6986                 } while (next_if(','));
6987         }
6988         rem_anchor_token(',');
6989         rem_anchor_token(')');
6990         expect(')', end_error);
6991
6992 end_error:
6993         return literal;
6994 }
6995
6996 /**
6997  * Parses a primary expression.
6998  */
6999 static expression_t *parse_primary_expression(void)
7000 {
7001         switch (token.type) {
7002         case T_false:                        return parse_boolean_literal(false);
7003         case T_true:                         return parse_boolean_literal(true);
7004         case T_INTEGER:
7005         case T_INTEGER_OCTAL:
7006         case T_INTEGER_HEXADECIMAL:
7007         case T_FLOATINGPOINT:
7008         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
7009         case T_CHARACTER_CONSTANT:           return parse_character_constant();
7010         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7011         case T_STRING_LITERAL:
7012         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
7013         case T___FUNCTION__:
7014         case T___func__:                     return parse_function_keyword();
7015         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7016         case T___FUNCSIG__:                  return parse_funcsig_keyword();
7017         case T___FUNCDNAME__:                return parse_funcdname_keyword();
7018         case T___builtin_offsetof:           return parse_offsetof();
7019         case T___builtin_va_start:           return parse_va_start();
7020         case T___builtin_va_arg:             return parse_va_arg();
7021         case T___builtin_va_copy:            return parse_va_copy();
7022         case T___builtin_isgreater:
7023         case T___builtin_isgreaterequal:
7024         case T___builtin_isless:
7025         case T___builtin_islessequal:
7026         case T___builtin_islessgreater:
7027         case T___builtin_isunordered:        return parse_compare_builtin();
7028         case T___builtin_constant_p:         return parse_builtin_constant();
7029         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7030         case T__assume:                      return parse_assume();
7031         case T_ANDAND:
7032                 if (GNU_MODE)
7033                         return parse_label_address();
7034                 break;
7035
7036         case '(':                            return parse_parenthesized_expression();
7037         case T___noop:                       return parse_noop_expression();
7038
7039         /* Gracefully handle type names while parsing expressions. */
7040         case T_COLONCOLON:
7041                 return parse_reference();
7042         case T_IDENTIFIER:
7043                 if (!is_typedef_symbol(token.symbol)) {
7044                         return parse_reference();
7045                 }
7046                 /* FALLTHROUGH */
7047         DECLARATION_START {
7048                 source_position_t const  pos = *HERE;
7049                 declaration_specifiers_t specifiers;
7050                 parse_declaration_specifiers(&specifiers);
7051                 type_t const *const type = parse_abstract_declarator(specifiers.type);
7052                 errorf(&pos, "encountered type '%T' while parsing expression", type);
7053                 return create_invalid_expression();
7054         }
7055         }
7056
7057         errorf(HERE, "unexpected token %K, expected an expression", &token);
7058         eat_until_anchor();
7059         return create_invalid_expression();
7060 }
7061
7062 static expression_t *parse_array_expression(expression_t *left)
7063 {
7064         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7065         array_access_expression_t *const arr  = &expr->array_access;
7066
7067         eat('[');
7068         add_anchor_token(']');
7069
7070         expression_t *const inside = parse_expression();
7071
7072         type_t *const orig_type_left   = left->base.type;
7073         type_t *const orig_type_inside = inside->base.type;
7074
7075         type_t *const type_left   = skip_typeref(orig_type_left);
7076         type_t *const type_inside = skip_typeref(orig_type_inside);
7077
7078         expression_t *ref;
7079         expression_t *idx;
7080         type_t       *idx_type;
7081         type_t       *res_type;
7082         if (is_type_pointer(type_left)) {
7083                 ref      = left;
7084                 idx      = inside;
7085                 idx_type = type_inside;
7086                 res_type = type_left->pointer.points_to;
7087                 goto check_idx;
7088         } else if (is_type_pointer(type_inside)) {
7089                 arr->flipped = true;
7090                 ref      = inside;
7091                 idx      = left;
7092                 idx_type = type_left;
7093                 res_type = type_inside->pointer.points_to;
7094 check_idx:
7095                 res_type = automatic_type_conversion(res_type);
7096                 if (!is_type_integer(idx_type)) {
7097                         errorf(&idx->base.source_position, "array subscript must have integer type");
7098                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR) && warning.char_subscripts) {
7099                         warningf(&idx->base.source_position, "array subscript has char type");
7100                 }
7101         } else {
7102                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7103                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
7104                 }
7105                 res_type = type_error_type;
7106                 ref      = left;
7107                 idx      = inside;
7108         }
7109
7110         arr->array_ref = ref;
7111         arr->index     = idx;
7112         arr->base.type = res_type;
7113
7114         rem_anchor_token(']');
7115         expect(']', end_error);
7116 end_error:
7117         return expr;
7118 }
7119
7120 static expression_t *parse_typeprop(expression_kind_t const kind)
7121 {
7122         expression_t  *tp_expression = allocate_expression_zero(kind);
7123         tp_expression->base.type     = type_size_t;
7124
7125         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7126
7127         /* we only refer to a type property, mark this case */
7128         bool old     = in_type_prop;
7129         in_type_prop = true;
7130
7131         type_t       *orig_type;
7132         expression_t *expression;
7133         if (token.type == '(' && is_declaration_specifier(look_ahead(1))) {
7134                 next_token();
7135                 add_anchor_token(')');
7136                 orig_type = parse_typename();
7137                 rem_anchor_token(')');
7138                 expect(')', end_error);
7139
7140                 if (token.type == '{') {
7141                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7142                          * starting with a compound literal */
7143                         expression = parse_compound_literal(orig_type);
7144                         goto typeprop_expression;
7145                 }
7146         } else {
7147                 expression = parse_subexpression(PREC_UNARY);
7148
7149 typeprop_expression:
7150                 tp_expression->typeprop.tp_expression = expression;
7151
7152                 orig_type = revert_automatic_type_conversion(expression);
7153                 expression->base.type = orig_type;
7154         }
7155
7156         tp_expression->typeprop.type   = orig_type;
7157         type_t const* const type       = skip_typeref(orig_type);
7158         char   const*       wrong_type = NULL;
7159         if (is_type_incomplete(type)) {
7160                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7161                         wrong_type = "incomplete";
7162         } else if (type->kind == TYPE_FUNCTION) {
7163                 if (GNU_MODE) {
7164                         /* function types are allowed (and return 1) */
7165                         if (warning.other) {
7166                                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7167                                 warningf(&tp_expression->base.source_position,
7168                                          "%s expression with function argument returns invalid result", what);
7169                         }
7170                 } else {
7171                         wrong_type = "function";
7172                 }
7173         } else {
7174                 if (is_type_incomplete(type))
7175                         wrong_type = "incomplete";
7176         }
7177         if (type->kind == TYPE_BITFIELD)
7178                 wrong_type = "bitfield";
7179
7180         if (wrong_type != NULL) {
7181                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7182                 errorf(&tp_expression->base.source_position,
7183                                 "operand of %s expression must not be of %s type '%T'",
7184                                 what, wrong_type, orig_type);
7185         }
7186
7187 end_error:
7188         in_type_prop = old;
7189         return tp_expression;
7190 }
7191
7192 static expression_t *parse_sizeof(void)
7193 {
7194         return parse_typeprop(EXPR_SIZEOF);
7195 }
7196
7197 static expression_t *parse_alignof(void)
7198 {
7199         return parse_typeprop(EXPR_ALIGNOF);
7200 }
7201
7202 static expression_t *parse_select_expression(expression_t *addr)
7203 {
7204         assert(token.type == '.' || token.type == T_MINUSGREATER);
7205         bool select_left_arrow = (token.type == T_MINUSGREATER);
7206         source_position_t const pos = *HERE;
7207         next_token();
7208
7209         if (token.type != T_IDENTIFIER) {
7210                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7211                 return create_invalid_expression();
7212         }
7213         symbol_t *symbol = token.symbol;
7214         next_token();
7215
7216         type_t *const orig_type = addr->base.type;
7217         type_t *const type      = skip_typeref(orig_type);
7218
7219         type_t *type_left;
7220         bool    saw_error = false;
7221         if (is_type_pointer(type)) {
7222                 if (!select_left_arrow) {
7223                         errorf(&pos,
7224                                "request for member '%Y' in something not a struct or union, but '%T'",
7225                                symbol, orig_type);
7226                         saw_error = true;
7227                 }
7228                 type_left = skip_typeref(type->pointer.points_to);
7229         } else {
7230                 if (select_left_arrow && is_type_valid(type)) {
7231                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7232                         saw_error = true;
7233                 }
7234                 type_left = type;
7235         }
7236
7237         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7238             type_left->kind != TYPE_COMPOUND_UNION) {
7239
7240                 if (is_type_valid(type_left) && !saw_error) {
7241                         errorf(&pos,
7242                                "request for member '%Y' in something not a struct or union, but '%T'",
7243                                symbol, type_left);
7244                 }
7245                 return create_invalid_expression();
7246         }
7247
7248         compound_t *compound = type_left->compound.compound;
7249         if (!compound->complete) {
7250                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7251                        symbol, type_left);
7252                 return create_invalid_expression();
7253         }
7254
7255         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7256         expression_t      *result     =
7257                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7258
7259         if (result == NULL) {
7260                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7261                 return create_invalid_expression();
7262         }
7263
7264         return result;
7265 }
7266
7267 static void check_call_argument(type_t          *expected_type,
7268                                 call_argument_t *argument, unsigned pos)
7269 {
7270         type_t         *expected_type_skip = skip_typeref(expected_type);
7271         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7272         expression_t   *arg_expr           = argument->expression;
7273         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7274
7275         /* handle transparent union gnu extension */
7276         if (is_type_union(expected_type_skip)
7277                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7278                 compound_t *union_decl  = expected_type_skip->compound.compound;
7279                 type_t     *best_type   = NULL;
7280                 entity_t   *entry       = union_decl->members.entities;
7281                 for ( ; entry != NULL; entry = entry->base.next) {
7282                         assert(is_declaration(entry));
7283                         type_t *decl_type = entry->declaration.type;
7284                         error = semantic_assign(decl_type, arg_expr);
7285                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7286                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7287                                 continue;
7288
7289                         if (error == ASSIGN_SUCCESS) {
7290                                 best_type = decl_type;
7291                         } else if (best_type == NULL) {
7292                                 best_type = decl_type;
7293                         }
7294                 }
7295
7296                 if (best_type != NULL) {
7297                         expected_type = best_type;
7298                 }
7299         }
7300
7301         error                = semantic_assign(expected_type, arg_expr);
7302         argument->expression = create_implicit_cast(arg_expr, expected_type);
7303
7304         if (error != ASSIGN_SUCCESS) {
7305                 /* report exact scope in error messages (like "in argument 3") */
7306                 char buf[64];
7307                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7308                 report_assign_error(error, expected_type, arg_expr, buf,
7309                                     &arg_expr->base.source_position);
7310         } else if (warning.traditional || warning.conversion) {
7311                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7312                 if (!types_compatible(expected_type_skip, promoted_type) &&
7313                     !types_compatible(expected_type_skip, type_void_ptr) &&
7314                     !types_compatible(type_void_ptr,      promoted_type)) {
7315                         /* Deliberately show the skipped types in this warning */
7316                         warningf(&arg_expr->base.source_position,
7317                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7318                                 pos, expected_type_skip, promoted_type);
7319                 }
7320         }
7321 }
7322
7323 /**
7324  * Handle the semantic restrictions of builtin calls
7325  */
7326 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7327         switch (call->function->reference.entity->function.btk) {
7328                 case bk_gnu_builtin_return_address:
7329                 case bk_gnu_builtin_frame_address: {
7330                         /* argument must be constant */
7331                         call_argument_t *argument = call->arguments;
7332
7333                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7334                                 errorf(&call->base.source_position,
7335                                        "argument of '%Y' must be a constant expression",
7336                                        call->function->reference.entity->base.symbol);
7337                         }
7338                         break;
7339                 }
7340                 case bk_gnu_builtin_object_size:
7341                         if (call->arguments == NULL)
7342                                 break;
7343
7344                         call_argument_t *arg = call->arguments->next;
7345                         if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7346                                 errorf(&call->base.source_position,
7347                                            "second argument of '%Y' must be a constant expression",
7348                                            call->function->reference.entity->base.symbol);
7349                         }
7350                         break;
7351                 case bk_gnu_builtin_prefetch:
7352                         /* second and third argument must be constant if existent */
7353                         if (call->arguments == NULL)
7354                                 break;
7355                         call_argument_t *rw = call->arguments->next;
7356                         call_argument_t *locality = NULL;
7357
7358                         if (rw != NULL) {
7359                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7360                                         errorf(&call->base.source_position,
7361                                                "second argument of '%Y' must be a constant expression",
7362                                                call->function->reference.entity->base.symbol);
7363                                 }
7364                                 locality = rw->next;
7365                         }
7366                         if (locality != NULL) {
7367                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7368                                         errorf(&call->base.source_position,
7369                                                "third argument of '%Y' must be a constant expression",
7370                                                call->function->reference.entity->base.symbol);
7371                                 }
7372                                 locality = rw->next;
7373                         }
7374                         break;
7375                 default:
7376                         break;
7377         }
7378 }
7379
7380 /**
7381  * Parse a call expression, ie. expression '( ... )'.
7382  *
7383  * @param expression  the function address
7384  */
7385 static expression_t *parse_call_expression(expression_t *expression)
7386 {
7387         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7388         call_expression_t *call   = &result->call;
7389         call->function            = expression;
7390
7391         type_t *const orig_type = expression->base.type;
7392         type_t *const type      = skip_typeref(orig_type);
7393
7394         function_type_t *function_type = NULL;
7395         if (is_type_pointer(type)) {
7396                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7397
7398                 if (is_type_function(to_type)) {
7399                         function_type   = &to_type->function;
7400                         call->base.type = function_type->return_type;
7401                 }
7402         }
7403
7404         if (function_type == NULL && is_type_valid(type)) {
7405                 errorf(HERE,
7406                        "called object '%E' (type '%T') is not a pointer to a function",
7407                        expression, orig_type);
7408         }
7409
7410         /* parse arguments */
7411         eat('(');
7412         add_anchor_token(')');
7413         add_anchor_token(',');
7414
7415         if (token.type != ')') {
7416                 call_argument_t **anchor = &call->arguments;
7417                 do {
7418                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7419                         argument->expression = parse_assignment_expression();
7420
7421                         *anchor = argument;
7422                         anchor  = &argument->next;
7423                 } while (next_if(','));
7424         }
7425         rem_anchor_token(',');
7426         rem_anchor_token(')');
7427         expect(')', end_error);
7428
7429         if (function_type == NULL)
7430                 return result;
7431
7432         /* check type and count of call arguments */
7433         function_parameter_t *parameter = function_type->parameters;
7434         call_argument_t      *argument  = call->arguments;
7435         if (!function_type->unspecified_parameters) {
7436                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7437                                 parameter = parameter->next, argument = argument->next) {
7438                         check_call_argument(parameter->type, argument, ++pos);
7439                 }
7440
7441                 if (parameter != NULL) {
7442                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7443                 } else if (argument != NULL && !function_type->variadic) {
7444                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7445                 }
7446         }
7447
7448         /* do default promotion for other arguments */
7449         for (; argument != NULL; argument = argument->next) {
7450                 type_t *argument_type = argument->expression->base.type;
7451                 if (!is_type_object(skip_typeref(argument_type))) {
7452                         errorf(&argument->expression->base.source_position,
7453                                "call argument '%E' must not be void", argument->expression);
7454                 }
7455
7456                 argument_type = get_default_promoted_type(argument_type);
7457
7458                 argument->expression
7459                         = create_implicit_cast(argument->expression, argument_type);
7460         }
7461
7462         check_format(call);
7463
7464         if (warning.aggregate_return &&
7465             is_type_compound(skip_typeref(function_type->return_type))) {
7466                 warningf(&expression->base.source_position,
7467                          "function call has aggregate value");
7468         }
7469
7470         if (expression->kind == EXPR_REFERENCE) {
7471                 reference_expression_t *reference = &expression->reference;
7472                 if (reference->entity->kind == ENTITY_FUNCTION &&
7473                     reference->entity->function.btk != bk_none)
7474                         handle_builtin_argument_restrictions(call);
7475         }
7476
7477 end_error:
7478         return result;
7479 }
7480
7481 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7482
7483 static bool same_compound_type(const type_t *type1, const type_t *type2)
7484 {
7485         return
7486                 is_type_compound(type1) &&
7487                 type1->kind == type2->kind &&
7488                 type1->compound.compound == type2->compound.compound;
7489 }
7490
7491 static expression_t const *get_reference_address(expression_t const *expr)
7492 {
7493         bool regular_take_address = true;
7494         for (;;) {
7495                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7496                         expr = expr->unary.value;
7497                 } else {
7498                         regular_take_address = false;
7499                 }
7500
7501                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7502                         break;
7503
7504                 expr = expr->unary.value;
7505         }
7506
7507         if (expr->kind != EXPR_REFERENCE)
7508                 return NULL;
7509
7510         /* special case for functions which are automatically converted to a
7511          * pointer to function without an extra TAKE_ADDRESS operation */
7512         if (!regular_take_address &&
7513                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7514                 return NULL;
7515         }
7516
7517         return expr;
7518 }
7519
7520 static void warn_reference_address_as_bool(expression_t const* expr)
7521 {
7522         if (!warning.address)
7523                 return;
7524
7525         expr = get_reference_address(expr);
7526         if (expr != NULL) {
7527                 source_position_t const *const pos = &expr->base.source_position;
7528                 entity_t          const *const ent = expr->reference.entity;
7529                 warningf(pos, "the address of '%N' will always evaluate as 'true'", ent);
7530         }
7531 }
7532
7533 static void warn_assignment_in_condition(const expression_t *const expr)
7534 {
7535         if (!warning.parentheses)
7536                 return;
7537         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7538                 return;
7539         if (expr->base.parenthesized)
7540                 return;
7541         warningf(&expr->base.source_position,
7542                         "suggest parentheses around assignment used as truth value");
7543 }
7544
7545 static void semantic_condition(expression_t const *const expr,
7546                                char const *const context)
7547 {
7548         type_t *const type = skip_typeref(expr->base.type);
7549         if (is_type_scalar(type)) {
7550                 warn_reference_address_as_bool(expr);
7551                 warn_assignment_in_condition(expr);
7552         } else if (is_type_valid(type)) {
7553                 errorf(&expr->base.source_position,
7554                                 "%s must have scalar type", context);
7555         }
7556 }
7557
7558 /**
7559  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7560  *
7561  * @param expression  the conditional expression
7562  */
7563 static expression_t *parse_conditional_expression(expression_t *expression)
7564 {
7565         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7566
7567         conditional_expression_t *conditional = &result->conditional;
7568         conditional->condition                = expression;
7569
7570         eat('?');
7571         add_anchor_token(':');
7572
7573         /* §6.5.15:2  The first operand shall have scalar type. */
7574         semantic_condition(expression, "condition of conditional operator");
7575
7576         expression_t *true_expression = expression;
7577         bool          gnu_cond = false;
7578         if (GNU_MODE && token.type == ':') {
7579                 gnu_cond = true;
7580         } else {
7581                 true_expression = parse_expression();
7582         }
7583         rem_anchor_token(':');
7584         expect(':', end_error);
7585 end_error:;
7586         expression_t *false_expression =
7587                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7588
7589         type_t *const orig_true_type  = true_expression->base.type;
7590         type_t *const orig_false_type = false_expression->base.type;
7591         type_t *const true_type       = skip_typeref(orig_true_type);
7592         type_t *const false_type      = skip_typeref(orig_false_type);
7593
7594         /* 6.5.15.3 */
7595         type_t *result_type;
7596         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7597                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7598                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7599                 if (true_expression->kind == EXPR_UNARY_THROW) {
7600                         result_type = false_type;
7601                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7602                         result_type = true_type;
7603                 } else {
7604                         if (warning.other && (
7605                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7606                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7607                                         )) {
7608                                 warningf(&conditional->base.source_position,
7609                                                 "ISO C forbids conditional expression with only one void side");
7610                         }
7611                         result_type = type_void;
7612                 }
7613         } else if (is_type_arithmetic(true_type)
7614                    && is_type_arithmetic(false_type)) {
7615                 result_type = semantic_arithmetic(true_type, false_type);
7616         } else if (same_compound_type(true_type, false_type)) {
7617                 /* just take 1 of the 2 types */
7618                 result_type = true_type;
7619         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7620                 type_t *pointer_type;
7621                 type_t *other_type;
7622                 expression_t *other_expression;
7623                 if (is_type_pointer(true_type) &&
7624                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7625                         pointer_type     = true_type;
7626                         other_type       = false_type;
7627                         other_expression = false_expression;
7628                 } else {
7629                         pointer_type     = false_type;
7630                         other_type       = true_type;
7631                         other_expression = true_expression;
7632                 }
7633
7634                 if (is_null_pointer_constant(other_expression)) {
7635                         result_type = pointer_type;
7636                 } else if (is_type_pointer(other_type)) {
7637                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7638                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7639
7640                         type_t *to;
7641                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7642                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7643                                 to = type_void;
7644                         } else if (types_compatible(get_unqualified_type(to1),
7645                                                     get_unqualified_type(to2))) {
7646                                 to = to1;
7647                         } else {
7648                                 if (warning.other) {
7649                                         warningf(&conditional->base.source_position,
7650                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7651                                                         true_type, false_type);
7652                                 }
7653                                 to = type_void;
7654                         }
7655
7656                         type_t *const type =
7657                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7658                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7659                 } else if (is_type_integer(other_type)) {
7660                         if (warning.other) {
7661                                 warningf(&conditional->base.source_position,
7662                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7663                         }
7664                         result_type = pointer_type;
7665                 } else {
7666                         goto types_incompatible;
7667                 }
7668         } else {
7669 types_incompatible:
7670                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7671                         type_error_incompatible("while parsing conditional",
7672                                                 &conditional->base.source_position, true_type,
7673                                                 false_type);
7674                 }
7675                 result_type = type_error_type;
7676         }
7677
7678         conditional->true_expression
7679                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7680         conditional->false_expression
7681                 = create_implicit_cast(false_expression, result_type);
7682         conditional->base.type = result_type;
7683         return result;
7684 }
7685
7686 /**
7687  * Parse an extension expression.
7688  */
7689 static expression_t *parse_extension(void)
7690 {
7691         eat(T___extension__);
7692
7693         bool old_gcc_extension   = in_gcc_extension;
7694         in_gcc_extension         = true;
7695         expression_t *expression = parse_subexpression(PREC_UNARY);
7696         in_gcc_extension         = old_gcc_extension;
7697         return expression;
7698 }
7699
7700 /**
7701  * Parse a __builtin_classify_type() expression.
7702  */
7703 static expression_t *parse_builtin_classify_type(void)
7704 {
7705         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7706         result->base.type    = type_int;
7707
7708         eat(T___builtin_classify_type);
7709
7710         expect('(', end_error);
7711         add_anchor_token(')');
7712         expression_t *expression = parse_expression();
7713         rem_anchor_token(')');
7714         expect(')', end_error);
7715         result->classify_type.type_expression = expression;
7716
7717         return result;
7718 end_error:
7719         return create_invalid_expression();
7720 }
7721
7722 /**
7723  * Parse a delete expression
7724  * ISO/IEC 14882:1998(E) §5.3.5
7725  */
7726 static expression_t *parse_delete(void)
7727 {
7728         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7729         result->base.type          = type_void;
7730
7731         eat(T_delete);
7732
7733         if (next_if('[')) {
7734                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7735                 expect(']', end_error);
7736 end_error:;
7737         }
7738
7739         expression_t *const value = parse_subexpression(PREC_CAST);
7740         result->unary.value = value;
7741
7742         type_t *const type = skip_typeref(value->base.type);
7743         if (!is_type_pointer(type)) {
7744                 if (is_type_valid(type)) {
7745                         errorf(&value->base.source_position,
7746                                         "operand of delete must have pointer type");
7747                 }
7748         } else if (warning.other &&
7749                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7750                 warningf(&value->base.source_position,
7751                                 "deleting 'void*' is undefined");
7752         }
7753
7754         return result;
7755 }
7756
7757 /**
7758  * Parse a throw expression
7759  * ISO/IEC 14882:1998(E) §15:1
7760  */
7761 static expression_t *parse_throw(void)
7762 {
7763         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7764         result->base.type          = type_void;
7765
7766         eat(T_throw);
7767
7768         expression_t *value = NULL;
7769         switch (token.type) {
7770                 EXPRESSION_START {
7771                         value = parse_assignment_expression();
7772                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7773                         type_t *const orig_type = value->base.type;
7774                         type_t *const type      = skip_typeref(orig_type);
7775                         if (is_type_incomplete(type)) {
7776                                 errorf(&value->base.source_position,
7777                                                 "cannot throw object of incomplete type '%T'", orig_type);
7778                         } else if (is_type_pointer(type)) {
7779                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7780                                 if (is_type_incomplete(points_to) &&
7781                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7782                                         errorf(&value->base.source_position,
7783                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7784                                 }
7785                         }
7786                 }
7787
7788                 default:
7789                         break;
7790         }
7791         result->unary.value = value;
7792
7793         return result;
7794 }
7795
7796 static bool check_pointer_arithmetic(const source_position_t *source_position,
7797                                      type_t *pointer_type,
7798                                      type_t *orig_pointer_type)
7799 {
7800         type_t *points_to = pointer_type->pointer.points_to;
7801         points_to = skip_typeref(points_to);
7802
7803         if (is_type_incomplete(points_to)) {
7804                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7805                         errorf(source_position,
7806                                "arithmetic with pointer to incomplete type '%T' not allowed",
7807                                orig_pointer_type);
7808                         return false;
7809                 } else if (warning.pointer_arith) {
7810                         warningf(source_position,
7811                                  "pointer of type '%T' used in arithmetic",
7812                                  orig_pointer_type);
7813                 }
7814         } else if (is_type_function(points_to)) {
7815                 if (!GNU_MODE) {
7816                         errorf(source_position,
7817                                "arithmetic with pointer to function type '%T' not allowed",
7818                                orig_pointer_type);
7819                         return false;
7820                 } else if (warning.pointer_arith) {
7821                         warningf(source_position,
7822                                  "pointer to a function '%T' used in arithmetic",
7823                                  orig_pointer_type);
7824                 }
7825         }
7826         return true;
7827 }
7828
7829 static bool is_lvalue(const expression_t *expression)
7830 {
7831         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7832         switch (expression->kind) {
7833         case EXPR_ARRAY_ACCESS:
7834         case EXPR_COMPOUND_LITERAL:
7835         case EXPR_REFERENCE:
7836         case EXPR_SELECT:
7837         case EXPR_UNARY_DEREFERENCE:
7838                 return true;
7839
7840         default: {
7841                 type_t *type = skip_typeref(expression->base.type);
7842                 return
7843                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7844                         is_type_reference(type) ||
7845                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7846                          * error before, which maybe prevented properly recognizing it as
7847                          * lvalue. */
7848                         !is_type_valid(type);
7849         }
7850         }
7851 }
7852
7853 static void semantic_incdec(unary_expression_t *expression)
7854 {
7855         type_t *const orig_type = expression->value->base.type;
7856         type_t *const type      = skip_typeref(orig_type);
7857         if (is_type_pointer(type)) {
7858                 if (!check_pointer_arithmetic(&expression->base.source_position,
7859                                               type, orig_type)) {
7860                         return;
7861                 }
7862         } else if (!is_type_real(type) && is_type_valid(type)) {
7863                 /* TODO: improve error message */
7864                 errorf(&expression->base.source_position,
7865                        "operation needs an arithmetic or pointer type");
7866                 return;
7867         }
7868         if (!is_lvalue(expression->value)) {
7869                 /* TODO: improve error message */
7870                 errorf(&expression->base.source_position, "lvalue required as operand");
7871         }
7872         expression->base.type = orig_type;
7873 }
7874
7875 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7876 {
7877         type_t *const orig_type = expression->value->base.type;
7878         type_t *const type      = skip_typeref(orig_type);
7879         if (!is_type_arithmetic(type)) {
7880                 if (is_type_valid(type)) {
7881                         /* TODO: improve error message */
7882                         errorf(&expression->base.source_position,
7883                                 "operation needs an arithmetic type");
7884                 }
7885                 return;
7886         }
7887
7888         expression->base.type = orig_type;
7889 }
7890
7891 static void semantic_unexpr_plus(unary_expression_t *expression)
7892 {
7893         semantic_unexpr_arithmetic(expression);
7894         if (warning.traditional)
7895                 warningf(&expression->base.source_position,
7896                         "traditional C rejects the unary plus operator");
7897 }
7898
7899 static void semantic_not(unary_expression_t *expression)
7900 {
7901         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7902         semantic_condition(expression->value, "operand of !");
7903         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7904 }
7905
7906 static void semantic_unexpr_integer(unary_expression_t *expression)
7907 {
7908         type_t *const orig_type = expression->value->base.type;
7909         type_t *const type      = skip_typeref(orig_type);
7910         if (!is_type_integer(type)) {
7911                 if (is_type_valid(type)) {
7912                         errorf(&expression->base.source_position,
7913                                "operand of ~ must be of integer type");
7914                 }
7915                 return;
7916         }
7917
7918         expression->base.type = orig_type;
7919 }
7920
7921 static void semantic_dereference(unary_expression_t *expression)
7922 {
7923         type_t *const orig_type = expression->value->base.type;
7924         type_t *const type      = skip_typeref(orig_type);
7925         if (!is_type_pointer(type)) {
7926                 if (is_type_valid(type)) {
7927                         errorf(&expression->base.source_position,
7928                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7929                 }
7930                 return;
7931         }
7932
7933         type_t *result_type   = type->pointer.points_to;
7934         result_type           = automatic_type_conversion(result_type);
7935         expression->base.type = result_type;
7936 }
7937
7938 /**
7939  * Record that an address is taken (expression represents an lvalue).
7940  *
7941  * @param expression       the expression
7942  * @param may_be_register  if true, the expression might be an register
7943  */
7944 static void set_address_taken(expression_t *expression, bool may_be_register)
7945 {
7946         if (expression->kind != EXPR_REFERENCE)
7947                 return;
7948
7949         entity_t *const entity = expression->reference.entity;
7950
7951         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7952                 return;
7953
7954         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7955                         && !may_be_register) {
7956                 source_position_t const *const pos = &expression->base.source_position;
7957                 errorf(pos, "address of register '%N' requested", entity);
7958         }
7959
7960         if (entity->kind == ENTITY_VARIABLE) {
7961                 entity->variable.address_taken = true;
7962         } else {
7963                 assert(entity->kind == ENTITY_PARAMETER);
7964                 entity->parameter.address_taken = true;
7965         }
7966 }
7967
7968 /**
7969  * Check the semantic of the address taken expression.
7970  */
7971 static void semantic_take_addr(unary_expression_t *expression)
7972 {
7973         expression_t *value = expression->value;
7974         value->base.type    = revert_automatic_type_conversion(value);
7975
7976         type_t *orig_type = value->base.type;
7977         type_t *type      = skip_typeref(orig_type);
7978         if (!is_type_valid(type))
7979                 return;
7980
7981         /* §6.5.3.2 */
7982         if (!is_lvalue(value)) {
7983                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7984         }
7985         if (type->kind == TYPE_BITFIELD) {
7986                 errorf(&expression->base.source_position,
7987                        "'&' not allowed on object with bitfield type '%T'",
7988                        type);
7989         }
7990
7991         set_address_taken(value, false);
7992
7993         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7994 }
7995
7996 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
7997 static expression_t *parse_##unexpression_type(void)                         \
7998 {                                                                            \
7999         expression_t *unary_expression                                           \
8000                 = allocate_expression_zero(unexpression_type);                       \
8001         eat(token_type);                                                         \
8002         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
8003                                                                                  \
8004         sfunc(&unary_expression->unary);                                         \
8005                                                                                  \
8006         return unary_expression;                                                 \
8007 }
8008
8009 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8010                                semantic_unexpr_arithmetic)
8011 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8012                                semantic_unexpr_plus)
8013 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8014                                semantic_not)
8015 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8016                                semantic_dereference)
8017 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8018                                semantic_take_addr)
8019 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8020                                semantic_unexpr_integer)
8021 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8022                                semantic_incdec)
8023 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8024                                semantic_incdec)
8025
8026 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8027                                                sfunc)                         \
8028 static expression_t *parse_##unexpression_type(expression_t *left)            \
8029 {                                                                             \
8030         expression_t *unary_expression                                            \
8031                 = allocate_expression_zero(unexpression_type);                        \
8032         eat(token_type);                                                          \
8033         unary_expression->unary.value = left;                                     \
8034                                                                                   \
8035         sfunc(&unary_expression->unary);                                          \
8036                                                                               \
8037         return unary_expression;                                                  \
8038 }
8039
8040 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8041                                        EXPR_UNARY_POSTFIX_INCREMENT,
8042                                        semantic_incdec)
8043 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8044                                        EXPR_UNARY_POSTFIX_DECREMENT,
8045                                        semantic_incdec)
8046
8047 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8048 {
8049         /* TODO: handle complex + imaginary types */
8050
8051         type_left  = get_unqualified_type(type_left);
8052         type_right = get_unqualified_type(type_right);
8053
8054         /* §6.3.1.8 Usual arithmetic conversions */
8055         if (type_left == type_long_double || type_right == type_long_double) {
8056                 return type_long_double;
8057         } else if (type_left == type_double || type_right == type_double) {
8058                 return type_double;
8059         } else if (type_left == type_float || type_right == type_float) {
8060                 return type_float;
8061         }
8062
8063         type_left  = promote_integer(type_left);
8064         type_right = promote_integer(type_right);
8065
8066         if (type_left == type_right)
8067                 return type_left;
8068
8069         bool const signed_left  = is_type_signed(type_left);
8070         bool const signed_right = is_type_signed(type_right);
8071         int const  rank_left    = get_rank(type_left);
8072         int const  rank_right   = get_rank(type_right);
8073
8074         if (signed_left == signed_right)
8075                 return rank_left >= rank_right ? type_left : type_right;
8076
8077         int     s_rank;
8078         int     u_rank;
8079         type_t *s_type;
8080         type_t *u_type;
8081         if (signed_left) {
8082                 s_rank = rank_left;
8083                 s_type = type_left;
8084                 u_rank = rank_right;
8085                 u_type = type_right;
8086         } else {
8087                 s_rank = rank_right;
8088                 s_type = type_right;
8089                 u_rank = rank_left;
8090                 u_type = type_left;
8091         }
8092
8093         if (u_rank >= s_rank)
8094                 return u_type;
8095
8096         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8097          * easier here... */
8098         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8099                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8100                 return s_type;
8101
8102         switch (s_rank) {
8103                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8104                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8105                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8106
8107                 default: panic("invalid atomic type");
8108         }
8109 }
8110
8111 /**
8112  * Check the semantic restrictions for a binary expression.
8113  */
8114 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8115 {
8116         expression_t *const left            = expression->left;
8117         expression_t *const right           = expression->right;
8118         type_t       *const orig_type_left  = left->base.type;
8119         type_t       *const orig_type_right = right->base.type;
8120         type_t       *const type_left       = skip_typeref(orig_type_left);
8121         type_t       *const type_right      = skip_typeref(orig_type_right);
8122
8123         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8124                 /* TODO: improve error message */
8125                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8126                         errorf(&expression->base.source_position,
8127                                "operation needs arithmetic types");
8128                 }
8129                 return;
8130         }
8131
8132         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8133         expression->left      = create_implicit_cast(left, arithmetic_type);
8134         expression->right     = create_implicit_cast(right, arithmetic_type);
8135         expression->base.type = arithmetic_type;
8136 }
8137
8138 static void semantic_binexpr_integer(binary_expression_t *const expression)
8139 {
8140         expression_t *const left            = expression->left;
8141         expression_t *const right           = expression->right;
8142         type_t       *const orig_type_left  = left->base.type;
8143         type_t       *const orig_type_right = right->base.type;
8144         type_t       *const type_left       = skip_typeref(orig_type_left);
8145         type_t       *const type_right      = skip_typeref(orig_type_right);
8146
8147         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8148                 /* TODO: improve error message */
8149                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8150                         errorf(&expression->base.source_position,
8151                                "operation needs integer types");
8152                 }
8153                 return;
8154         }
8155
8156         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8157         expression->left      = create_implicit_cast(left, result_type);
8158         expression->right     = create_implicit_cast(right, result_type);
8159         expression->base.type = result_type;
8160 }
8161
8162 static void warn_div_by_zero(binary_expression_t const *const expression)
8163 {
8164         if (!warning.div_by_zero ||
8165             !is_type_integer(expression->base.type))
8166                 return;
8167
8168         expression_t const *const right = expression->right;
8169         /* The type of the right operand can be different for /= */
8170         if (is_type_integer(right->base.type)                    &&
8171             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8172             !fold_constant_to_bool(right)) {
8173                 warningf(&expression->base.source_position, "division by zero");
8174         }
8175 }
8176
8177 /**
8178  * Check the semantic restrictions for a div/mod expression.
8179  */
8180 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8181 {
8182         semantic_binexpr_arithmetic(expression);
8183         warn_div_by_zero(expression);
8184 }
8185
8186 static void warn_addsub_in_shift(const expression_t *const expr)
8187 {
8188         if (expr->base.parenthesized)
8189                 return;
8190
8191         char op;
8192         switch (expr->kind) {
8193                 case EXPR_BINARY_ADD: op = '+'; break;
8194                 case EXPR_BINARY_SUB: op = '-'; break;
8195                 default:              return;
8196         }
8197
8198         warningf(&expr->base.source_position,
8199                         "suggest parentheses around '%c' inside shift", op);
8200 }
8201
8202 static bool semantic_shift(binary_expression_t *expression)
8203 {
8204         expression_t *const left            = expression->left;
8205         expression_t *const right           = expression->right;
8206         type_t       *const orig_type_left  = left->base.type;
8207         type_t       *const orig_type_right = right->base.type;
8208         type_t       *      type_left       = skip_typeref(orig_type_left);
8209         type_t       *      type_right      = skip_typeref(orig_type_right);
8210
8211         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8212                 /* TODO: improve error message */
8213                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8214                         errorf(&expression->base.source_position,
8215                                "operands of shift operation must have integer types");
8216                 }
8217                 return false;
8218         }
8219
8220         type_left = promote_integer(type_left);
8221
8222         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8223                 long count = fold_constant_to_int(right);
8224                 if (count < 0) {
8225                         warningf(&right->base.source_position,
8226                                         "shift count must be non-negative");
8227                 } else if ((unsigned long)count >=
8228                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8229                         warningf(&right->base.source_position,
8230                                         "shift count must be less than type width");
8231                 }
8232         }
8233
8234         type_right        = promote_integer(type_right);
8235         expression->right = create_implicit_cast(right, type_right);
8236
8237         return true;
8238 }
8239
8240 static void semantic_shift_op(binary_expression_t *expression)
8241 {
8242         expression_t *const left  = expression->left;
8243         expression_t *const right = expression->right;
8244
8245         if (!semantic_shift(expression))
8246                 return;
8247
8248         if (warning.parentheses) {
8249                 warn_addsub_in_shift(left);
8250                 warn_addsub_in_shift(right);
8251         }
8252
8253         type_t *const orig_type_left = left->base.type;
8254         type_t *      type_left      = skip_typeref(orig_type_left);
8255
8256         type_left             = promote_integer(type_left);
8257         expression->left      = create_implicit_cast(left, type_left);
8258         expression->base.type = type_left;
8259 }
8260
8261 static void semantic_add(binary_expression_t *expression)
8262 {
8263         expression_t *const left            = expression->left;
8264         expression_t *const right           = expression->right;
8265         type_t       *const orig_type_left  = left->base.type;
8266         type_t       *const orig_type_right = right->base.type;
8267         type_t       *const type_left       = skip_typeref(orig_type_left);
8268         type_t       *const type_right      = skip_typeref(orig_type_right);
8269
8270         /* §6.5.6 */
8271         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8272                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8273                 expression->left  = create_implicit_cast(left, arithmetic_type);
8274                 expression->right = create_implicit_cast(right, arithmetic_type);
8275                 expression->base.type = arithmetic_type;
8276         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8277                 check_pointer_arithmetic(&expression->base.source_position,
8278                                          type_left, orig_type_left);
8279                 expression->base.type = type_left;
8280         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8281                 check_pointer_arithmetic(&expression->base.source_position,
8282                                          type_right, orig_type_right);
8283                 expression->base.type = type_right;
8284         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8285                 errorf(&expression->base.source_position,
8286                        "invalid operands to binary + ('%T', '%T')",
8287                        orig_type_left, orig_type_right);
8288         }
8289 }
8290
8291 static void semantic_sub(binary_expression_t *expression)
8292 {
8293         expression_t            *const left            = expression->left;
8294         expression_t            *const right           = expression->right;
8295         type_t                  *const orig_type_left  = left->base.type;
8296         type_t                  *const orig_type_right = right->base.type;
8297         type_t                  *const type_left       = skip_typeref(orig_type_left);
8298         type_t                  *const type_right      = skip_typeref(orig_type_right);
8299         source_position_t const *const pos             = &expression->base.source_position;
8300
8301         /* §5.6.5 */
8302         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8303                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8304                 expression->left        = create_implicit_cast(left, arithmetic_type);
8305                 expression->right       = create_implicit_cast(right, arithmetic_type);
8306                 expression->base.type =  arithmetic_type;
8307         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8308                 check_pointer_arithmetic(&expression->base.source_position,
8309                                          type_left, orig_type_left);
8310                 expression->base.type = type_left;
8311         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8312                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8313                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8314                 if (!types_compatible(unqual_left, unqual_right)) {
8315                         errorf(pos,
8316                                "subtracting pointers to incompatible types '%T' and '%T'",
8317                                orig_type_left, orig_type_right);
8318                 } else if (!is_type_object(unqual_left)) {
8319                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8320                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8321                                        orig_type_left);
8322                         } else if (warning.other) {
8323                                 warningf(pos, "subtracting pointers to void");
8324                         }
8325                 }
8326                 expression->base.type = type_ptrdiff_t;
8327         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8328                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8329                        orig_type_left, orig_type_right);
8330         }
8331 }
8332
8333 static void warn_string_literal_address(expression_t const* expr)
8334 {
8335         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8336                 expr = expr->unary.value;
8337                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8338                         return;
8339                 expr = expr->unary.value;
8340         }
8341
8342         if (expr->kind == EXPR_STRING_LITERAL
8343                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8344                 warningf(&expr->base.source_position,
8345                         "comparison with string literal results in unspecified behaviour");
8346         }
8347 }
8348
8349 static bool maybe_negative(expression_t const *const expr)
8350 {
8351         switch (is_constant_expression(expr)) {
8352                 case EXPR_CLASS_ERROR:    return false;
8353                 case EXPR_CLASS_CONSTANT: return fold_constant_to_int(expr) < 0;
8354                 default:                  return true;
8355         }
8356 }
8357
8358 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8359 {
8360         if (warning.address) {
8361                 warn_string_literal_address(expr);
8362
8363                 expression_t const* const ref = get_reference_address(expr);
8364                 if (ref != NULL && is_null_pointer_constant(other)) {
8365                         entity_t const *const ent = ref->reference.entity;
8366                         warningf(pos, "the address of '%N' will never be NULL", ent);
8367                 }
8368         }
8369
8370         if (warning.parentheses && !expr->base.parenthesized) {
8371                 switch (expr->base.kind) {
8372                         case EXPR_BINARY_LESS:
8373                         case EXPR_BINARY_GREATER:
8374                         case EXPR_BINARY_LESSEQUAL:
8375                         case EXPR_BINARY_GREATEREQUAL:
8376                         case EXPR_BINARY_NOTEQUAL:
8377                         case EXPR_BINARY_EQUAL:
8378                                 warningf(pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8379                                 break;
8380                         default:
8381                                 break;
8382                 }
8383         }
8384 }
8385
8386 /**
8387  * Check the semantics of comparison expressions.
8388  *
8389  * @param expression   The expression to check.
8390  */
8391 static void semantic_comparison(binary_expression_t *expression)
8392 {
8393         source_position_t const *const pos   = &expression->base.source_position;
8394         expression_t            *const left  = expression->left;
8395         expression_t            *const right = expression->right;
8396
8397         warn_comparison(pos, left, right);
8398         warn_comparison(pos, right, left);
8399
8400         type_t *orig_type_left  = left->base.type;
8401         type_t *orig_type_right = right->base.type;
8402         type_t *type_left       = skip_typeref(orig_type_left);
8403         type_t *type_right      = skip_typeref(orig_type_right);
8404
8405         /* TODO non-arithmetic types */
8406         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8407                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8408
8409                 /* test for signed vs unsigned compares */
8410                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8411                         bool const signed_left  = is_type_signed(type_left);
8412                         bool const signed_right = is_type_signed(type_right);
8413                         if (signed_left != signed_right) {
8414                                 /* FIXME long long needs better const folding magic */
8415                                 /* TODO check whether constant value can be represented by other type */
8416                                 if ((signed_left  && maybe_negative(left)) ||
8417                                                 (signed_right && maybe_negative(right))) {
8418                                         warningf(pos, "comparison between signed and unsigned");
8419                                 }
8420                         }
8421                 }
8422
8423                 expression->left        = create_implicit_cast(left, arithmetic_type);
8424                 expression->right       = create_implicit_cast(right, arithmetic_type);
8425                 expression->base.type   = arithmetic_type;
8426                 if (warning.float_equal &&
8427                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8428                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8429                     is_type_float(arithmetic_type)) {
8430                         warningf(pos, "comparing floating point with == or != is unsafe");
8431                 }
8432         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8433                 /* TODO check compatibility */
8434         } else if (is_type_pointer(type_left)) {
8435                 expression->right = create_implicit_cast(right, type_left);
8436         } else if (is_type_pointer(type_right)) {
8437                 expression->left = create_implicit_cast(left, type_right);
8438         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8439                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8440         }
8441         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8442 }
8443
8444 /**
8445  * Checks if a compound type has constant fields.
8446  */
8447 static bool has_const_fields(const compound_type_t *type)
8448 {
8449         compound_t *compound = type->compound;
8450         entity_t   *entry    = compound->members.entities;
8451
8452         for (; entry != NULL; entry = entry->base.next) {
8453                 if (!is_declaration(entry))
8454                         continue;
8455
8456                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8457                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8458                         return true;
8459         }
8460
8461         return false;
8462 }
8463
8464 static bool is_valid_assignment_lhs(expression_t const* const left)
8465 {
8466         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8467         type_t *const type_left      = skip_typeref(orig_type_left);
8468
8469         if (!is_lvalue(left)) {
8470                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8471                        left);
8472                 return false;
8473         }
8474
8475         if (left->kind == EXPR_REFERENCE
8476                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8477                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8478                 return false;
8479         }
8480
8481         if (is_type_array(type_left)) {
8482                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8483                 return false;
8484         }
8485         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8486                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8487                        orig_type_left);
8488                 return false;
8489         }
8490         if (is_type_incomplete(type_left)) {
8491                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8492                        left, orig_type_left);
8493                 return false;
8494         }
8495         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8496                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8497                        left, orig_type_left);
8498                 return false;
8499         }
8500
8501         return true;
8502 }
8503
8504 static void semantic_arithmetic_assign(binary_expression_t *expression)
8505 {
8506         expression_t *left            = expression->left;
8507         expression_t *right           = expression->right;
8508         type_t       *orig_type_left  = left->base.type;
8509         type_t       *orig_type_right = right->base.type;
8510
8511         if (!is_valid_assignment_lhs(left))
8512                 return;
8513
8514         type_t *type_left  = skip_typeref(orig_type_left);
8515         type_t *type_right = skip_typeref(orig_type_right);
8516
8517         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8518                 /* TODO: improve error message */
8519                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8520                         errorf(&expression->base.source_position,
8521                                "operation needs arithmetic types");
8522                 }
8523                 return;
8524         }
8525
8526         /* combined instructions are tricky. We can't create an implicit cast on
8527          * the left side, because we need the uncasted form for the store.
8528          * The ast2firm pass has to know that left_type must be right_type
8529          * for the arithmetic operation and create a cast by itself */
8530         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8531         expression->right       = create_implicit_cast(right, arithmetic_type);
8532         expression->base.type   = type_left;
8533 }
8534
8535 static void semantic_divmod_assign(binary_expression_t *expression)
8536 {
8537         semantic_arithmetic_assign(expression);
8538         warn_div_by_zero(expression);
8539 }
8540
8541 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8542 {
8543         expression_t *const left            = expression->left;
8544         expression_t *const right           = expression->right;
8545         type_t       *const orig_type_left  = left->base.type;
8546         type_t       *const orig_type_right = right->base.type;
8547         type_t       *const type_left       = skip_typeref(orig_type_left);
8548         type_t       *const type_right      = skip_typeref(orig_type_right);
8549
8550         if (!is_valid_assignment_lhs(left))
8551                 return;
8552
8553         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8554                 /* combined instructions are tricky. We can't create an implicit cast on
8555                  * the left side, because we need the uncasted form for the store.
8556                  * The ast2firm pass has to know that left_type must be right_type
8557                  * for the arithmetic operation and create a cast by itself */
8558                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8559                 expression->right     = create_implicit_cast(right, arithmetic_type);
8560                 expression->base.type = type_left;
8561         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8562                 check_pointer_arithmetic(&expression->base.source_position,
8563                                          type_left, orig_type_left);
8564                 expression->base.type = type_left;
8565         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8566                 errorf(&expression->base.source_position,
8567                        "incompatible types '%T' and '%T' in assignment",
8568                        orig_type_left, orig_type_right);
8569         }
8570 }
8571
8572 static void semantic_integer_assign(binary_expression_t *expression)
8573 {
8574         expression_t *left            = expression->left;
8575         expression_t *right           = expression->right;
8576         type_t       *orig_type_left  = left->base.type;
8577         type_t       *orig_type_right = right->base.type;
8578
8579         if (!is_valid_assignment_lhs(left))
8580                 return;
8581
8582         type_t *type_left  = skip_typeref(orig_type_left);
8583         type_t *type_right = skip_typeref(orig_type_right);
8584
8585         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8586                 /* TODO: improve error message */
8587                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8588                         errorf(&expression->base.source_position,
8589                                "operation needs integer types");
8590                 }
8591                 return;
8592         }
8593
8594         /* combined instructions are tricky. We can't create an implicit cast on
8595          * the left side, because we need the uncasted form for the store.
8596          * The ast2firm pass has to know that left_type must be right_type
8597          * for the arithmetic operation and create a cast by itself */
8598         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8599         expression->right       = create_implicit_cast(right, arithmetic_type);
8600         expression->base.type   = type_left;
8601 }
8602
8603 static void semantic_shift_assign(binary_expression_t *expression)
8604 {
8605         expression_t *left           = expression->left;
8606
8607         if (!is_valid_assignment_lhs(left))
8608                 return;
8609
8610         if (!semantic_shift(expression))
8611                 return;
8612
8613         expression->base.type = skip_typeref(left->base.type);
8614 }
8615
8616 static void warn_logical_and_within_or(const expression_t *const expr)
8617 {
8618         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8619                 return;
8620         if (expr->base.parenthesized)
8621                 return;
8622         warningf(&expr->base.source_position,
8623                         "suggest parentheses around && within ||");
8624 }
8625
8626 /**
8627  * Check the semantic restrictions of a logical expression.
8628  */
8629 static void semantic_logical_op(binary_expression_t *expression)
8630 {
8631         /* §6.5.13:2  Each of the operands shall have scalar type.
8632          * §6.5.14:2  Each of the operands shall have scalar type. */
8633         semantic_condition(expression->left,   "left operand of logical operator");
8634         semantic_condition(expression->right, "right operand of logical operator");
8635         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8636                         warning.parentheses) {
8637                 warn_logical_and_within_or(expression->left);
8638                 warn_logical_and_within_or(expression->right);
8639         }
8640         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8641 }
8642
8643 /**
8644  * Check the semantic restrictions of a binary assign expression.
8645  */
8646 static void semantic_binexpr_assign(binary_expression_t *expression)
8647 {
8648         expression_t *left           = expression->left;
8649         type_t       *orig_type_left = left->base.type;
8650
8651         if (!is_valid_assignment_lhs(left))
8652                 return;
8653
8654         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8655         report_assign_error(error, orig_type_left, expression->right,
8656                         "assignment", &left->base.source_position);
8657         expression->right = create_implicit_cast(expression->right, orig_type_left);
8658         expression->base.type = orig_type_left;
8659 }
8660
8661 /**
8662  * Determine if the outermost operation (or parts thereof) of the given
8663  * expression has no effect in order to generate a warning about this fact.
8664  * Therefore in some cases this only examines some of the operands of the
8665  * expression (see comments in the function and examples below).
8666  * Examples:
8667  *   f() + 23;    // warning, because + has no effect
8668  *   x || f();    // no warning, because x controls execution of f()
8669  *   x ? y : f(); // warning, because y has no effect
8670  *   (void)x;     // no warning to be able to suppress the warning
8671  * This function can NOT be used for an "expression has definitely no effect"-
8672  * analysis. */
8673 static bool expression_has_effect(const expression_t *const expr)
8674 {
8675         switch (expr->kind) {
8676                 case EXPR_UNKNOWN:                    break;
8677                 case EXPR_INVALID:                    return true; /* do NOT warn */
8678                 case EXPR_REFERENCE:                  return false;
8679                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8680                 case EXPR_LABEL_ADDRESS:              return false;
8681
8682                 /* suppress the warning for microsoft __noop operations */
8683                 case EXPR_LITERAL_MS_NOOP:            return true;
8684                 case EXPR_LITERAL_BOOLEAN:
8685                 case EXPR_LITERAL_CHARACTER:
8686                 case EXPR_LITERAL_WIDE_CHARACTER:
8687                 case EXPR_LITERAL_INTEGER:
8688                 case EXPR_LITERAL_INTEGER_OCTAL:
8689                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8690                 case EXPR_LITERAL_FLOATINGPOINT:
8691                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8692                 case EXPR_STRING_LITERAL:             return false;
8693                 case EXPR_WIDE_STRING_LITERAL:        return false;
8694
8695                 case EXPR_CALL: {
8696                         const call_expression_t *const call = &expr->call;
8697                         if (call->function->kind != EXPR_REFERENCE)
8698                                 return true;
8699
8700                         switch (call->function->reference.entity->function.btk) {
8701                                 /* FIXME: which builtins have no effect? */
8702                                 default:                      return true;
8703                         }
8704                 }
8705
8706                 /* Generate the warning if either the left or right hand side of a
8707                  * conditional expression has no effect */
8708                 case EXPR_CONDITIONAL: {
8709                         conditional_expression_t const *const cond = &expr->conditional;
8710                         expression_t             const *const t    = cond->true_expression;
8711                         return
8712                                 (t == NULL || expression_has_effect(t)) &&
8713                                 expression_has_effect(cond->false_expression);
8714                 }
8715
8716                 case EXPR_SELECT:                     return false;
8717                 case EXPR_ARRAY_ACCESS:               return false;
8718                 case EXPR_SIZEOF:                     return false;
8719                 case EXPR_CLASSIFY_TYPE:              return false;
8720                 case EXPR_ALIGNOF:                    return false;
8721
8722                 case EXPR_FUNCNAME:                   return false;
8723                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8724                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8725                 case EXPR_OFFSETOF:                   return false;
8726                 case EXPR_VA_START:                   return true;
8727                 case EXPR_VA_ARG:                     return true;
8728                 case EXPR_VA_COPY:                    return true;
8729                 case EXPR_STATEMENT:                  return true; // TODO
8730                 case EXPR_COMPOUND_LITERAL:           return false;
8731
8732                 case EXPR_UNARY_NEGATE:               return false;
8733                 case EXPR_UNARY_PLUS:                 return false;
8734                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8735                 case EXPR_UNARY_NOT:                  return false;
8736                 case EXPR_UNARY_DEREFERENCE:          return false;
8737                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8738                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8739                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8740                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8741                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8742
8743                 /* Treat void casts as if they have an effect in order to being able to
8744                  * suppress the warning */
8745                 case EXPR_UNARY_CAST: {
8746                         type_t *const type = skip_typeref(expr->base.type);
8747                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8748                 }
8749
8750                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8751                 case EXPR_UNARY_ASSUME:               return true;
8752                 case EXPR_UNARY_DELETE:               return true;
8753                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8754                 case EXPR_UNARY_THROW:                return true;
8755
8756                 case EXPR_BINARY_ADD:                 return false;
8757                 case EXPR_BINARY_SUB:                 return false;
8758                 case EXPR_BINARY_MUL:                 return false;
8759                 case EXPR_BINARY_DIV:                 return false;
8760                 case EXPR_BINARY_MOD:                 return false;
8761                 case EXPR_BINARY_EQUAL:               return false;
8762                 case EXPR_BINARY_NOTEQUAL:            return false;
8763                 case EXPR_BINARY_LESS:                return false;
8764                 case EXPR_BINARY_LESSEQUAL:           return false;
8765                 case EXPR_BINARY_GREATER:             return false;
8766                 case EXPR_BINARY_GREATEREQUAL:        return false;
8767                 case EXPR_BINARY_BITWISE_AND:         return false;
8768                 case EXPR_BINARY_BITWISE_OR:          return false;
8769                 case EXPR_BINARY_BITWISE_XOR:         return false;
8770                 case EXPR_BINARY_SHIFTLEFT:           return false;
8771                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8772                 case EXPR_BINARY_ASSIGN:              return true;
8773                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8774                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8775                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8776                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8777                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8778                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8779                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8780                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8781                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8782                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8783
8784                 /* Only examine the right hand side of && and ||, because the left hand
8785                  * side already has the effect of controlling the execution of the right
8786                  * hand side */
8787                 case EXPR_BINARY_LOGICAL_AND:
8788                 case EXPR_BINARY_LOGICAL_OR:
8789                 /* Only examine the right hand side of a comma expression, because the left
8790                  * hand side has a separate warning */
8791                 case EXPR_BINARY_COMMA:
8792                         return expression_has_effect(expr->binary.right);
8793
8794                 case EXPR_BINARY_ISGREATER:           return false;
8795                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8796                 case EXPR_BINARY_ISLESS:              return false;
8797                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8798                 case EXPR_BINARY_ISLESSGREATER:       return false;
8799                 case EXPR_BINARY_ISUNORDERED:         return false;
8800         }
8801
8802         internal_errorf(HERE, "unexpected expression");
8803 }
8804
8805 static void semantic_comma(binary_expression_t *expression)
8806 {
8807         if (warning.unused_value) {
8808                 const expression_t *const left = expression->left;
8809                 if (!expression_has_effect(left)) {
8810                         warningf(&left->base.source_position,
8811                                  "left-hand operand of comma expression has no effect");
8812                 }
8813         }
8814         expression->base.type = expression->right->base.type;
8815 }
8816
8817 /**
8818  * @param prec_r precedence of the right operand
8819  */
8820 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8821 static expression_t *parse_##binexpression_type(expression_t *left)          \
8822 {                                                                            \
8823         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8824         binexpr->binary.left  = left;                                            \
8825         eat(token_type);                                                         \
8826                                                                              \
8827         expression_t *right = parse_subexpression(prec_r);                       \
8828                                                                              \
8829         binexpr->binary.right = right;                                           \
8830         sfunc(&binexpr->binary);                                                 \
8831                                                                              \
8832         return binexpr;                                                          \
8833 }
8834
8835 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8836 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8837 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8838 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8839 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8840 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8841 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8842 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8843 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8844 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8845 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8846 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8847 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8848 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8849 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8850 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8851 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8852 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8853 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8854 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8855 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8856 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8857 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8858 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8859 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8860 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8861 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8862 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8863 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8864 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8865
8866
8867 static expression_t *parse_subexpression(precedence_t precedence)
8868 {
8869         if (token.type < 0) {
8870                 return expected_expression_error();
8871         }
8872
8873         expression_parser_function_t *parser
8874                 = &expression_parsers[token.type];
8875         source_position_t             source_position = token.source_position;
8876         expression_t                 *left;
8877
8878         if (parser->parser != NULL) {
8879                 left = parser->parser();
8880         } else {
8881                 left = parse_primary_expression();
8882         }
8883         assert(left != NULL);
8884         left->base.source_position = source_position;
8885
8886         while (true) {
8887                 if (token.type < 0) {
8888                         return expected_expression_error();
8889                 }
8890
8891                 parser = &expression_parsers[token.type];
8892                 if (parser->infix_parser == NULL)
8893                         break;
8894                 if (parser->infix_precedence < precedence)
8895                         break;
8896
8897                 left = parser->infix_parser(left);
8898
8899                 assert(left != NULL);
8900                 assert(left->kind != EXPR_UNKNOWN);
8901                 left->base.source_position = source_position;
8902         }
8903
8904         return left;
8905 }
8906
8907 /**
8908  * Parse an expression.
8909  */
8910 static expression_t *parse_expression(void)
8911 {
8912         return parse_subexpression(PREC_EXPRESSION);
8913 }
8914
8915 /**
8916  * Register a parser for a prefix-like operator.
8917  *
8918  * @param parser      the parser function
8919  * @param token_type  the token type of the prefix token
8920  */
8921 static void register_expression_parser(parse_expression_function parser,
8922                                        int token_type)
8923 {
8924         expression_parser_function_t *entry = &expression_parsers[token_type];
8925
8926         if (entry->parser != NULL) {
8927                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
8928                 panic("trying to register multiple expression parsers for a token");
8929         }
8930         entry->parser = parser;
8931 }
8932
8933 /**
8934  * Register a parser for an infix operator with given precedence.
8935  *
8936  * @param parser      the parser function
8937  * @param token_type  the token type of the infix operator
8938  * @param precedence  the precedence of the operator
8939  */
8940 static void register_infix_parser(parse_expression_infix_function parser,
8941                                   int token_type, precedence_t precedence)
8942 {
8943         expression_parser_function_t *entry = &expression_parsers[token_type];
8944
8945         if (entry->infix_parser != NULL) {
8946                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
8947                 panic("trying to register multiple infix expression parsers for a "
8948                       "token");
8949         }
8950         entry->infix_parser     = parser;
8951         entry->infix_precedence = precedence;
8952 }
8953
8954 /**
8955  * Initialize the expression parsers.
8956  */
8957 static void init_expression_parsers(void)
8958 {
8959         memset(&expression_parsers, 0, sizeof(expression_parsers));
8960
8961         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8962         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8963         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8964         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8965         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8966         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8967         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8968         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8969         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8970         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8971         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8972         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8973         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8974         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8975         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8976         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8977         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8978         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8979         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8980         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8981         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8982         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8983         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8984         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8985         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8986         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8987         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8988         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8989         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8990         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8991         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8992         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8993         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8994         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8995         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8996         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8997         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8998
8999         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9000         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9001         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9002         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9003         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9004         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9005         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9006         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9007         register_expression_parser(parse_sizeof,                      T_sizeof);
9008         register_expression_parser(parse_alignof,                     T___alignof__);
9009         register_expression_parser(parse_extension,                   T___extension__);
9010         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9011         register_expression_parser(parse_delete,                      T_delete);
9012         register_expression_parser(parse_throw,                       T_throw);
9013 }
9014
9015 /**
9016  * Parse a asm statement arguments specification.
9017  */
9018 static asm_argument_t *parse_asm_arguments(bool is_out)
9019 {
9020         asm_argument_t  *result = NULL;
9021         asm_argument_t **anchor = &result;
9022
9023         while (token.type == T_STRING_LITERAL || token.type == '[') {
9024                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9025                 memset(argument, 0, sizeof(argument[0]));
9026
9027                 if (next_if('[')) {
9028                         if (token.type != T_IDENTIFIER) {
9029                                 parse_error_expected("while parsing asm argument",
9030                                                      T_IDENTIFIER, NULL);
9031                                 return NULL;
9032                         }
9033                         argument->symbol = token.symbol;
9034
9035                         expect(']', end_error);
9036                 }
9037
9038                 argument->constraints = parse_string_literals();
9039                 expect('(', end_error);
9040                 add_anchor_token(')');
9041                 expression_t *expression = parse_expression();
9042                 rem_anchor_token(')');
9043                 if (is_out) {
9044                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9045                          * change size or type representation (e.g. int -> long is ok, but
9046                          * int -> float is not) */
9047                         if (expression->kind == EXPR_UNARY_CAST) {
9048                                 type_t      *const type = expression->base.type;
9049                                 type_kind_t  const kind = type->kind;
9050                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9051                                         unsigned flags;
9052                                         unsigned size;
9053                                         if (kind == TYPE_ATOMIC) {
9054                                                 atomic_type_kind_t const akind = type->atomic.akind;
9055                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9056                                                 size  = get_atomic_type_size(akind);
9057                                         } else {
9058                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9059                                                 size  = get_atomic_type_size(get_intptr_kind());
9060                                         }
9061
9062                                         do {
9063                                                 expression_t *const value      = expression->unary.value;
9064                                                 type_t       *const value_type = value->base.type;
9065                                                 type_kind_t   const value_kind = value_type->kind;
9066
9067                                                 unsigned value_flags;
9068                                                 unsigned value_size;
9069                                                 if (value_kind == TYPE_ATOMIC) {
9070                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9071                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9072                                                         value_size  = get_atomic_type_size(value_akind);
9073                                                 } else if (value_kind == TYPE_POINTER) {
9074                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9075                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9076                                                 } else {
9077                                                         break;
9078                                                 }
9079
9080                                                 if (value_flags != flags || value_size != size)
9081                                                         break;
9082
9083                                                 expression = value;
9084                                         } while (expression->kind == EXPR_UNARY_CAST);
9085                                 }
9086                         }
9087
9088                         if (!is_lvalue(expression)) {
9089                                 errorf(&expression->base.source_position,
9090                                        "asm output argument is not an lvalue");
9091                         }
9092
9093                         if (argument->constraints.begin[0] == '=')
9094                                 determine_lhs_ent(expression, NULL);
9095                         else
9096                                 mark_vars_read(expression, NULL);
9097                 } else {
9098                         mark_vars_read(expression, NULL);
9099                 }
9100                 argument->expression = expression;
9101                 expect(')', end_error);
9102
9103                 set_address_taken(expression, true);
9104
9105                 *anchor = argument;
9106                 anchor  = &argument->next;
9107
9108                 if (!next_if(','))
9109                         break;
9110         }
9111
9112         return result;
9113 end_error:
9114         return NULL;
9115 }
9116
9117 /**
9118  * Parse a asm statement clobber specification.
9119  */
9120 static asm_clobber_t *parse_asm_clobbers(void)
9121 {
9122         asm_clobber_t *result  = NULL;
9123         asm_clobber_t **anchor = &result;
9124
9125         while (token.type == T_STRING_LITERAL) {
9126                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9127                 clobber->clobber       = parse_string_literals();
9128
9129                 *anchor = clobber;
9130                 anchor  = &clobber->next;
9131
9132                 if (!next_if(','))
9133                         break;
9134         }
9135
9136         return result;
9137 }
9138
9139 /**
9140  * Parse an asm statement.
9141  */
9142 static statement_t *parse_asm_statement(void)
9143 {
9144         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9145         asm_statement_t *asm_statement = &statement->asms;
9146
9147         eat(T_asm);
9148
9149         if (next_if(T_volatile))
9150                 asm_statement->is_volatile = true;
9151
9152         expect('(', end_error);
9153         add_anchor_token(')');
9154         if (token.type != T_STRING_LITERAL) {
9155                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
9156                 goto end_of_asm;
9157         }
9158         asm_statement->asm_text = parse_string_literals();
9159
9160         add_anchor_token(':');
9161         if (!next_if(':')) {
9162                 rem_anchor_token(':');
9163                 goto end_of_asm;
9164         }
9165
9166         asm_statement->outputs = parse_asm_arguments(true);
9167         if (!next_if(':')) {
9168                 rem_anchor_token(':');
9169                 goto end_of_asm;
9170         }
9171
9172         asm_statement->inputs = parse_asm_arguments(false);
9173         if (!next_if(':')) {
9174                 rem_anchor_token(':');
9175                 goto end_of_asm;
9176         }
9177         rem_anchor_token(':');
9178
9179         asm_statement->clobbers = parse_asm_clobbers();
9180
9181 end_of_asm:
9182         rem_anchor_token(')');
9183         expect(')', end_error);
9184         expect(';', end_error);
9185
9186         if (asm_statement->outputs == NULL) {
9187                 /* GCC: An 'asm' instruction without any output operands will be treated
9188                  * identically to a volatile 'asm' instruction. */
9189                 asm_statement->is_volatile = true;
9190         }
9191
9192         return statement;
9193 end_error:
9194         return create_invalid_statement();
9195 }
9196
9197 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9198 {
9199         statement_t *inner_stmt;
9200         switch (token.type) {
9201                 case '}':
9202                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9203                         inner_stmt = create_invalid_statement();
9204                         break;
9205
9206                 case ';':
9207                         if (label->kind == STATEMENT_LABEL) {
9208                                 /* Eat an empty statement here, to avoid the warning about an empty
9209                                  * statement after a label.  label:; is commonly used to have a label
9210                                  * before a closing brace. */
9211                                 inner_stmt = create_empty_statement();
9212                                 next_token();
9213                                 break;
9214                         }
9215                         /* FALLTHROUGH */
9216
9217                 default:
9218                         inner_stmt = parse_statement();
9219                         /* ISO/IEC 14882:1998(E) §6:1/§6.7  Declarations are statements */
9220                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9221                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9222                         }
9223                         break;
9224         }
9225         return inner_stmt;
9226 }
9227
9228 /**
9229  * Parse a case statement.
9230  */
9231 static statement_t *parse_case_statement(void)
9232 {
9233         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9234         source_position_t *const pos       = &statement->base.source_position;
9235
9236         eat(T_case);
9237
9238         expression_t *const expression   = parse_expression();
9239         statement->case_label.expression = expression;
9240         expression_classification_t const expr_class = is_constant_expression(expression);
9241         if (expr_class != EXPR_CLASS_CONSTANT) {
9242                 if (expr_class != EXPR_CLASS_ERROR) {
9243                         errorf(pos, "case label does not reduce to an integer constant");
9244                 }
9245                 statement->case_label.is_bad = true;
9246         } else {
9247                 long const val = fold_constant_to_int(expression);
9248                 statement->case_label.first_case = val;
9249                 statement->case_label.last_case  = val;
9250         }
9251
9252         if (GNU_MODE) {
9253                 if (next_if(T_DOTDOTDOT)) {
9254                         expression_t *const end_range   = parse_expression();
9255                         statement->case_label.end_range = end_range;
9256                         expression_classification_t const end_class = is_constant_expression(end_range);
9257                         if (end_class != EXPR_CLASS_CONSTANT) {
9258                                 if (end_class != EXPR_CLASS_ERROR) {
9259                                         errorf(pos, "case range does not reduce to an integer constant");
9260                                 }
9261                                 statement->case_label.is_bad = true;
9262                         } else {
9263                                 long const val = fold_constant_to_int(end_range);
9264                                 statement->case_label.last_case = val;
9265
9266                                 if (warning.other && val < statement->case_label.first_case) {
9267                                         statement->case_label.is_empty_range = true;
9268                                         warningf(pos, "empty range specified");
9269                                 }
9270                         }
9271                 }
9272         }
9273
9274         PUSH_PARENT(statement);
9275
9276         expect(':', end_error);
9277 end_error:
9278
9279         if (current_switch != NULL) {
9280                 if (! statement->case_label.is_bad) {
9281                         /* Check for duplicate case values */
9282                         case_label_statement_t *c = &statement->case_label;
9283                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9284                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9285                                         continue;
9286
9287                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9288                                         continue;
9289
9290                                 errorf(pos, "duplicate case value (previously used %P)",
9291                                        &l->base.source_position);
9292                                 break;
9293                         }
9294                 }
9295                 /* link all cases into the switch statement */
9296                 if (current_switch->last_case == NULL) {
9297                         current_switch->first_case      = &statement->case_label;
9298                 } else {
9299                         current_switch->last_case->next = &statement->case_label;
9300                 }
9301                 current_switch->last_case = &statement->case_label;
9302         } else {
9303                 errorf(pos, "case label not within a switch statement");
9304         }
9305
9306         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9307
9308         POP_PARENT;
9309         return statement;
9310 }
9311
9312 /**
9313  * Parse a default statement.
9314  */
9315 static statement_t *parse_default_statement(void)
9316 {
9317         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9318
9319         eat(T_default);
9320
9321         PUSH_PARENT(statement);
9322
9323         expect(':', end_error);
9324 end_error:
9325
9326         if (current_switch != NULL) {
9327                 const case_label_statement_t *def_label = current_switch->default_label;
9328                 if (def_label != NULL) {
9329                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9330                 } else {
9331                         current_switch->default_label = &statement->case_label;
9332
9333                         /* link all cases into the switch statement */
9334                         if (current_switch->last_case == NULL) {
9335                                 current_switch->first_case      = &statement->case_label;
9336                         } else {
9337                                 current_switch->last_case->next = &statement->case_label;
9338                         }
9339                         current_switch->last_case = &statement->case_label;
9340                 }
9341         } else {
9342                 errorf(&statement->base.source_position,
9343                         "'default' label not within a switch statement");
9344         }
9345
9346         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9347
9348         POP_PARENT;
9349         return statement;
9350 }
9351
9352 /**
9353  * Parse a label statement.
9354  */
9355 static statement_t *parse_label_statement(void)
9356 {
9357         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9358         label_t     *const label     = get_label();
9359         statement->label.label = label;
9360
9361         PUSH_PARENT(statement);
9362
9363         /* if statement is already set then the label is defined twice,
9364          * otherwise it was just mentioned in a goto/local label declaration so far
9365          */
9366         source_position_t const* const pos = &statement->base.source_position;
9367         if (label->statement != NULL) {
9368                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9369         } else {
9370                 label->base.source_position = *pos;
9371                 label->statement            = statement;
9372         }
9373
9374         eat(':');
9375
9376         statement->label.statement = parse_label_inner_statement(statement, "label");
9377
9378         /* remember the labels in a list for later checking */
9379         *label_anchor = &statement->label;
9380         label_anchor  = &statement->label.next;
9381
9382         POP_PARENT;
9383         return statement;
9384 }
9385
9386 /**
9387  * Parse an if statement.
9388  */
9389 static statement_t *parse_if(void)
9390 {
9391         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9392
9393         eat(T_if);
9394
9395         PUSH_PARENT(statement);
9396
9397         add_anchor_token('{');
9398
9399         expect('(', end_error);
9400         add_anchor_token(')');
9401         expression_t *const expr = parse_expression();
9402         statement->ifs.condition = expr;
9403         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9404          *             scalar type. */
9405         semantic_condition(expr, "condition of 'if'-statment");
9406         mark_vars_read(expr, NULL);
9407         rem_anchor_token(')');
9408         expect(')', end_error);
9409
9410 end_error:
9411         rem_anchor_token('{');
9412
9413         add_anchor_token(T_else);
9414         statement_t *const true_stmt = parse_statement();
9415         statement->ifs.true_statement = true_stmt;
9416         rem_anchor_token(T_else);
9417
9418         if (next_if(T_else)) {
9419                 statement->ifs.false_statement = parse_statement();
9420         } else if (warning.parentheses &&
9421                         true_stmt->kind == STATEMENT_IF &&
9422                         true_stmt->ifs.false_statement != NULL) {
9423                 warningf(&true_stmt->base.source_position,
9424                                 "suggest explicit braces to avoid ambiguous 'else'");
9425         }
9426
9427         POP_PARENT;
9428         return statement;
9429 }
9430
9431 /**
9432  * Check that all enums are handled in a switch.
9433  *
9434  * @param statement  the switch statement to check
9435  */
9436 static void check_enum_cases(const switch_statement_t *statement)
9437 {
9438         const type_t *type = skip_typeref(statement->expression->base.type);
9439         if (! is_type_enum(type))
9440                 return;
9441         const enum_type_t *enumt = &type->enumt;
9442
9443         /* if we have a default, no warnings */
9444         if (statement->default_label != NULL)
9445                 return;
9446
9447         /* FIXME: calculation of value should be done while parsing */
9448         /* TODO: quadratic algorithm here. Change to an n log n one */
9449         long            last_value = -1;
9450         const entity_t *entry      = enumt->enume->base.next;
9451         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9452              entry = entry->base.next) {
9453                 const expression_t *expression = entry->enum_value.value;
9454                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9455                 bool                found      = false;
9456                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9457                         if (l->expression == NULL)
9458                                 continue;
9459                         if (l->first_case <= value && value <= l->last_case) {
9460                                 found = true;
9461                                 break;
9462                         }
9463                 }
9464                 if (!found) {
9465                         warningf(&statement->base.source_position, "'%N' not handled in switch", entry);
9466                 }
9467                 last_value = value;
9468         }
9469 }
9470
9471 /**
9472  * Parse a switch statement.
9473  */
9474 static statement_t *parse_switch(void)
9475 {
9476         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9477
9478         eat(T_switch);
9479
9480         PUSH_PARENT(statement);
9481
9482         expect('(', end_error);
9483         add_anchor_token(')');
9484         expression_t *const expr = parse_expression();
9485         mark_vars_read(expr, NULL);
9486         type_t       *      type = skip_typeref(expr->base.type);
9487         if (is_type_integer(type)) {
9488                 type = promote_integer(type);
9489                 if (warning.traditional) {
9490                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9491                                 warningf(&expr->base.source_position,
9492                                         "'%T' switch expression not converted to '%T' in ISO C",
9493                                         type, type_int);
9494                         }
9495                 }
9496         } else if (is_type_valid(type)) {
9497                 errorf(&expr->base.source_position,
9498                        "switch quantity is not an integer, but '%T'", type);
9499                 type = type_error_type;
9500         }
9501         statement->switchs.expression = create_implicit_cast(expr, type);
9502         expect(')', end_error);
9503         rem_anchor_token(')');
9504
9505         switch_statement_t *rem = current_switch;
9506         current_switch          = &statement->switchs;
9507         statement->switchs.body = parse_statement();
9508         current_switch          = rem;
9509
9510         if (warning.switch_default &&
9511             statement->switchs.default_label == NULL) {
9512                 warningf(&statement->base.source_position, "switch has no default case");
9513         }
9514         if (warning.switch_enum)
9515                 check_enum_cases(&statement->switchs);
9516
9517         POP_PARENT;
9518         return statement;
9519 end_error:
9520         POP_PARENT;
9521         return create_invalid_statement();
9522 }
9523
9524 static statement_t *parse_loop_body(statement_t *const loop)
9525 {
9526         statement_t *const rem = current_loop;
9527         current_loop = loop;
9528
9529         statement_t *const body = parse_statement();
9530
9531         current_loop = rem;
9532         return body;
9533 }
9534
9535 /**
9536  * Parse a while statement.
9537  */
9538 static statement_t *parse_while(void)
9539 {
9540         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9541
9542         eat(T_while);
9543
9544         PUSH_PARENT(statement);
9545
9546         expect('(', end_error);
9547         add_anchor_token(')');
9548         expression_t *const cond = parse_expression();
9549         statement->whiles.condition = cond;
9550         /* §6.8.5:2    The controlling expression of an iteration statement shall
9551          *             have scalar type. */
9552         semantic_condition(cond, "condition of 'while'-statement");
9553         mark_vars_read(cond, NULL);
9554         rem_anchor_token(')');
9555         expect(')', end_error);
9556
9557         statement->whiles.body = parse_loop_body(statement);
9558
9559         POP_PARENT;
9560         return statement;
9561 end_error:
9562         POP_PARENT;
9563         return create_invalid_statement();
9564 }
9565
9566 /**
9567  * Parse a do statement.
9568  */
9569 static statement_t *parse_do(void)
9570 {
9571         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9572
9573         eat(T_do);
9574
9575         PUSH_PARENT(statement);
9576
9577         add_anchor_token(T_while);
9578         statement->do_while.body = parse_loop_body(statement);
9579         rem_anchor_token(T_while);
9580
9581         expect(T_while, end_error);
9582         expect('(', end_error);
9583         add_anchor_token(')');
9584         expression_t *const cond = parse_expression();
9585         statement->do_while.condition = cond;
9586         /* §6.8.5:2    The controlling expression of an iteration statement shall
9587          *             have scalar type. */
9588         semantic_condition(cond, "condition of 'do-while'-statement");
9589         mark_vars_read(cond, NULL);
9590         rem_anchor_token(')');
9591         expect(')', end_error);
9592         expect(';', end_error);
9593
9594         POP_PARENT;
9595         return statement;
9596 end_error:
9597         POP_PARENT;
9598         return create_invalid_statement();
9599 }
9600
9601 /**
9602  * Parse a for statement.
9603  */
9604 static statement_t *parse_for(void)
9605 {
9606         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9607
9608         eat(T_for);
9609
9610         expect('(', end_error1);
9611         add_anchor_token(')');
9612
9613         PUSH_PARENT(statement);
9614
9615         size_t const  top       = environment_top();
9616         scope_t      *old_scope = scope_push(&statement->fors.scope);
9617
9618         bool old_gcc_extension = in_gcc_extension;
9619         while (next_if(T___extension__)) {
9620                 in_gcc_extension = true;
9621         }
9622
9623         if (next_if(';')) {
9624         } else if (is_declaration_specifier(&token)) {
9625                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9626         } else {
9627                 add_anchor_token(';');
9628                 expression_t *const init = parse_expression();
9629                 statement->fors.initialisation = init;
9630                 mark_vars_read(init, ENT_ANY);
9631                 if (warning.unused_value && !expression_has_effect(init)) {
9632                         warningf(&init->base.source_position,
9633                                         "initialisation of 'for'-statement has no effect");
9634                 }
9635                 rem_anchor_token(';');
9636                 expect(';', end_error2);
9637         }
9638         in_gcc_extension = old_gcc_extension;
9639
9640         if (token.type != ';') {
9641                 add_anchor_token(';');
9642                 expression_t *const cond = parse_expression();
9643                 statement->fors.condition = cond;
9644                 /* §6.8.5:2    The controlling expression of an iteration statement
9645                  *             shall have scalar type. */
9646                 semantic_condition(cond, "condition of 'for'-statement");
9647                 mark_vars_read(cond, NULL);
9648                 rem_anchor_token(';');
9649         }
9650         expect(';', end_error2);
9651         if (token.type != ')') {
9652                 expression_t *const step = parse_expression();
9653                 statement->fors.step = step;
9654                 mark_vars_read(step, ENT_ANY);
9655                 if (warning.unused_value && !expression_has_effect(step)) {
9656                         warningf(&step->base.source_position,
9657                                  "step of 'for'-statement has no effect");
9658                 }
9659         }
9660         expect(')', end_error2);
9661         rem_anchor_token(')');
9662         statement->fors.body = parse_loop_body(statement);
9663
9664         assert(current_scope == &statement->fors.scope);
9665         scope_pop(old_scope);
9666         environment_pop_to(top);
9667
9668         POP_PARENT;
9669         return statement;
9670
9671 end_error2:
9672         POP_PARENT;
9673         rem_anchor_token(')');
9674         assert(current_scope == &statement->fors.scope);
9675         scope_pop(old_scope);
9676         environment_pop_to(top);
9677         /* fallthrough */
9678
9679 end_error1:
9680         return create_invalid_statement();
9681 }
9682
9683 /**
9684  * Parse a goto statement.
9685  */
9686 static statement_t *parse_goto(void)
9687 {
9688         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9689         eat(T_goto);
9690
9691         if (GNU_MODE && next_if('*')) {
9692                 expression_t *expression = parse_expression();
9693                 mark_vars_read(expression, NULL);
9694
9695                 /* Argh: although documentation says the expression must be of type void*,
9696                  * gcc accepts anything that can be casted into void* without error */
9697                 type_t *type = expression->base.type;
9698
9699                 if (type != type_error_type) {
9700                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9701                                 errorf(&expression->base.source_position,
9702                                         "cannot convert to a pointer type");
9703                         } else if (warning.other && type != type_void_ptr) {
9704                                 warningf(&expression->base.source_position,
9705                                         "type of computed goto expression should be 'void*' not '%T'", type);
9706                         }
9707                         expression = create_implicit_cast(expression, type_void_ptr);
9708                 }
9709
9710                 statement->gotos.expression = expression;
9711         } else if (token.type == T_IDENTIFIER) {
9712                 label_t *const label = get_label();
9713                 label->used            = true;
9714                 statement->gotos.label = label;
9715         } else {
9716                 if (GNU_MODE)
9717                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9718                 else
9719                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9720                 eat_until_anchor();
9721                 return create_invalid_statement();
9722         }
9723
9724         /* remember the goto's in a list for later checking */
9725         *goto_anchor = &statement->gotos;
9726         goto_anchor  = &statement->gotos.next;
9727
9728         expect(';', end_error);
9729
9730 end_error:
9731         return statement;
9732 }
9733
9734 /**
9735  * Parse a continue statement.
9736  */
9737 static statement_t *parse_continue(void)
9738 {
9739         if (current_loop == NULL) {
9740                 errorf(HERE, "continue statement not within loop");
9741         }
9742
9743         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9744
9745         eat(T_continue);
9746         expect(';', end_error);
9747
9748 end_error:
9749         return statement;
9750 }
9751
9752 /**
9753  * Parse a break statement.
9754  */
9755 static statement_t *parse_break(void)
9756 {
9757         if (current_switch == NULL && current_loop == NULL) {
9758                 errorf(HERE, "break statement not within loop or switch");
9759         }
9760
9761         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9762
9763         eat(T_break);
9764         expect(';', end_error);
9765
9766 end_error:
9767         return statement;
9768 }
9769
9770 /**
9771  * Parse a __leave statement.
9772  */
9773 static statement_t *parse_leave_statement(void)
9774 {
9775         if (current_try == NULL) {
9776                 errorf(HERE, "__leave statement not within __try");
9777         }
9778
9779         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9780
9781         eat(T___leave);
9782         expect(';', end_error);
9783
9784 end_error:
9785         return statement;
9786 }
9787
9788 /**
9789  * Check if a given entity represents a local variable.
9790  */
9791 static bool is_local_variable(const entity_t *entity)
9792 {
9793         if (entity->kind != ENTITY_VARIABLE)
9794                 return false;
9795
9796         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9797         case STORAGE_CLASS_AUTO:
9798         case STORAGE_CLASS_REGISTER: {
9799                 const type_t *type = skip_typeref(entity->declaration.type);
9800                 if (is_type_function(type)) {
9801                         return false;
9802                 } else {
9803                         return true;
9804                 }
9805         }
9806         default:
9807                 return false;
9808         }
9809 }
9810
9811 /**
9812  * Check if a given expression represents a local variable.
9813  */
9814 static bool expression_is_local_variable(const expression_t *expression)
9815 {
9816         if (expression->base.kind != EXPR_REFERENCE) {
9817                 return false;
9818         }
9819         const entity_t *entity = expression->reference.entity;
9820         return is_local_variable(entity);
9821 }
9822
9823 /**
9824  * Check if a given expression represents a local variable and
9825  * return its declaration then, else return NULL.
9826  */
9827 entity_t *expression_is_variable(const expression_t *expression)
9828 {
9829         if (expression->base.kind != EXPR_REFERENCE) {
9830                 return NULL;
9831         }
9832         entity_t *entity = expression->reference.entity;
9833         if (entity->kind != ENTITY_VARIABLE)
9834                 return NULL;
9835
9836         return entity;
9837 }
9838
9839 /**
9840  * Parse a return statement.
9841  */
9842 static statement_t *parse_return(void)
9843 {
9844         eat(T_return);
9845
9846         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9847
9848         expression_t *return_value = NULL;
9849         if (token.type != ';') {
9850                 return_value = parse_expression();
9851                 mark_vars_read(return_value, NULL);
9852         }
9853
9854         const type_t *const func_type = skip_typeref(current_function->base.type);
9855         assert(is_type_function(func_type));
9856         type_t *const return_type = skip_typeref(func_type->function.return_type);
9857
9858         source_position_t const *const pos = &statement->base.source_position;
9859         if (return_value != NULL) {
9860                 type_t *return_value_type = skip_typeref(return_value->base.type);
9861
9862                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9863                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9864                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9865                                 /* Only warn in C mode, because GCC does the same */
9866                                 if (c_mode & _CXX || strict_mode) {
9867                                         errorf(pos,
9868                                                         "'return' with a value, in function returning 'void'");
9869                                 } else if (warning.other) {
9870                                         warningf(pos,
9871                                                         "'return' with a value, in function returning 'void'");
9872                                 }
9873                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9874                                 /* Only warn in C mode, because GCC does the same */
9875                                 if (strict_mode) {
9876                                         errorf(pos,
9877                                                         "'return' with expression in function returning 'void'");
9878                                 } else if (warning.other) {
9879                                         warningf(pos,
9880                                                         "'return' with expression in function returning 'void'");
9881                                 }
9882                         }
9883                 } else {
9884                         assign_error_t error = semantic_assign(return_type, return_value);
9885                         report_assign_error(error, return_type, return_value, "'return'",
9886                                             pos);
9887                 }
9888                 return_value = create_implicit_cast(return_value, return_type);
9889                 /* check for returning address of a local var */
9890                 if (warning.other && return_value != NULL
9891                     && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9892                         const expression_t *expression = return_value->unary.value;
9893                         if (expression_is_local_variable(expression)) {
9894                                 warningf(pos, "function returns address of local variable");
9895                         }
9896                 }
9897         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9898                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9899                 if (c_mode & _CXX || strict_mode) {
9900                         errorf(pos,
9901                                "'return' without value, in function returning non-void");
9902                 } else {
9903                         warningf(pos,
9904                                  "'return' without value, in function returning non-void");
9905                 }
9906         }
9907         statement->returns.value = return_value;
9908
9909         expect(';', end_error);
9910
9911 end_error:
9912         return statement;
9913 }
9914
9915 /**
9916  * Parse a declaration statement.
9917  */
9918 static statement_t *parse_declaration_statement(void)
9919 {
9920         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9921
9922         entity_t *before = current_scope->last_entity;
9923         if (GNU_MODE) {
9924                 parse_external_declaration();
9925         } else {
9926                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9927         }
9928
9929         declaration_statement_t *const decl  = &statement->declaration;
9930         entity_t                *const begin =
9931                 before != NULL ? before->base.next : current_scope->entities;
9932         decl->declarations_begin = begin;
9933         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9934
9935         return statement;
9936 }
9937
9938 /**
9939  * Parse an expression statement, ie. expr ';'.
9940  */
9941 static statement_t *parse_expression_statement(void)
9942 {
9943         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9944
9945         expression_t *const expr         = parse_expression();
9946         statement->expression.expression = expr;
9947         mark_vars_read(expr, ENT_ANY);
9948
9949         expect(';', end_error);
9950
9951 end_error:
9952         return statement;
9953 }
9954
9955 /**
9956  * Parse a microsoft __try { } __finally { } or
9957  * __try{ } __except() { }
9958  */
9959 static statement_t *parse_ms_try_statment(void)
9960 {
9961         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9962         eat(T___try);
9963
9964         PUSH_PARENT(statement);
9965
9966         ms_try_statement_t *rem = current_try;
9967         current_try = &statement->ms_try;
9968         statement->ms_try.try_statement = parse_compound_statement(false);
9969         current_try = rem;
9970
9971         POP_PARENT;
9972
9973         if (next_if(T___except)) {
9974                 expect('(', end_error);
9975                 add_anchor_token(')');
9976                 expression_t *const expr = parse_expression();
9977                 mark_vars_read(expr, NULL);
9978                 type_t       *      type = skip_typeref(expr->base.type);
9979                 if (is_type_integer(type)) {
9980                         type = promote_integer(type);
9981                 } else if (is_type_valid(type)) {
9982                         errorf(&expr->base.source_position,
9983                                "__expect expression is not an integer, but '%T'", type);
9984                         type = type_error_type;
9985                 }
9986                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9987                 rem_anchor_token(')');
9988                 expect(')', end_error);
9989                 statement->ms_try.final_statement = parse_compound_statement(false);
9990         } else if (next_if(T__finally)) {
9991                 statement->ms_try.final_statement = parse_compound_statement(false);
9992         } else {
9993                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9994                 return create_invalid_statement();
9995         }
9996         return statement;
9997 end_error:
9998         return create_invalid_statement();
9999 }
10000
10001 static statement_t *parse_empty_statement(void)
10002 {
10003         if (warning.empty_statement) {
10004                 warningf(HERE, "statement is empty");
10005         }
10006         statement_t *const statement = create_empty_statement();
10007         eat(';');
10008         return statement;
10009 }
10010
10011 static statement_t *parse_local_label_declaration(void)
10012 {
10013         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10014
10015         eat(T___label__);
10016
10017         entity_t *begin   = NULL;
10018         entity_t *end     = NULL;
10019         entity_t **anchor = &begin;
10020         do {
10021                 if (token.type != T_IDENTIFIER) {
10022                         parse_error_expected("while parsing local label declaration",
10023                                 T_IDENTIFIER, NULL);
10024                         goto end_error;
10025                 }
10026                 symbol_t *symbol = token.symbol;
10027                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10028                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10029                         source_position_t const *const ppos = &entity->base.source_position;
10030                         errorf(HERE, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
10031                 } else {
10032                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol);
10033                         entity->base.parent_scope    = current_scope;
10034                         entity->base.source_position = token.source_position;
10035
10036                         *anchor = entity;
10037                         anchor  = &entity->base.next;
10038                         end     = entity;
10039
10040                         environment_push(entity);
10041                 }
10042                 next_token();
10043         } while (next_if(','));
10044         expect(';', end_error);
10045 end_error:
10046         statement->declaration.declarations_begin = begin;
10047         statement->declaration.declarations_end   = end;
10048         return statement;
10049 }
10050
10051 static void parse_namespace_definition(void)
10052 {
10053         eat(T_namespace);
10054
10055         entity_t *entity = NULL;
10056         symbol_t *symbol = NULL;
10057
10058         if (token.type == T_IDENTIFIER) {
10059                 symbol = token.symbol;
10060                 next_token();
10061
10062                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10063                 if (entity != NULL
10064                                 && entity->kind != ENTITY_NAMESPACE
10065                                 && entity->base.parent_scope == current_scope) {
10066                         if (is_entity_valid(entity)) {
10067                                 error_redefined_as_different_kind(&token.source_position,
10068                                                 entity, ENTITY_NAMESPACE);
10069                         }
10070                         entity = NULL;
10071                 }
10072         }
10073
10074         if (entity == NULL) {
10075                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol);
10076                 entity->base.source_position = token.source_position;
10077                 entity->base.parent_scope    = current_scope;
10078         }
10079
10080         if (token.type == '=') {
10081                 /* TODO: parse namespace alias */
10082                 panic("namespace alias definition not supported yet");
10083         }
10084
10085         environment_push(entity);
10086         append_entity(current_scope, entity);
10087
10088         size_t const  top       = environment_top();
10089         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10090
10091         entity_t     *old_current_entity = current_entity;
10092         current_entity = entity;
10093
10094         expect('{', end_error);
10095         parse_externals();
10096         expect('}', end_error);
10097
10098 end_error:
10099         assert(current_scope == &entity->namespacee.members);
10100         assert(current_entity == entity);
10101         current_entity = old_current_entity;
10102         scope_pop(old_scope);
10103         environment_pop_to(top);
10104 }
10105
10106 /**
10107  * Parse a statement.
10108  * There's also parse_statement() which additionally checks for
10109  * "statement has no effect" warnings
10110  */
10111 static statement_t *intern_parse_statement(void)
10112 {
10113         statement_t *statement = NULL;
10114
10115         /* declaration or statement */
10116         add_anchor_token(';');
10117         switch (token.type) {
10118         case T_IDENTIFIER: {
10119                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10120                 if (la1_type == ':') {
10121                         statement = parse_label_statement();
10122                 } else if (is_typedef_symbol(token.symbol)) {
10123                         statement = parse_declaration_statement();
10124                 } else {
10125                         /* it's an identifier, the grammar says this must be an
10126                          * expression statement. However it is common that users mistype
10127                          * declaration types, so we guess a bit here to improve robustness
10128                          * for incorrect programs */
10129                         switch (la1_type) {
10130                         case '&':
10131                         case '*':
10132                                 if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL) {
10133                         default:
10134                                         statement = parse_expression_statement();
10135                                 } else {
10136                         DECLARATION_START
10137                         case T_IDENTIFIER:
10138                                         statement = parse_declaration_statement();
10139                                 }
10140                                 break;
10141                         }
10142                 }
10143                 break;
10144         }
10145
10146         case T___extension__:
10147                 /* This can be a prefix to a declaration or an expression statement.
10148                  * We simply eat it now and parse the rest with tail recursion. */
10149                 while (next_if(T___extension__)) {}
10150                 bool old_gcc_extension = in_gcc_extension;
10151                 in_gcc_extension       = true;
10152                 statement = intern_parse_statement();
10153                 in_gcc_extension = old_gcc_extension;
10154                 break;
10155
10156         DECLARATION_START
10157                 statement = parse_declaration_statement();
10158                 break;
10159
10160         case T___label__:
10161                 statement = parse_local_label_declaration();
10162                 break;
10163
10164         case ';':         statement = parse_empty_statement();         break;
10165         case '{':         statement = parse_compound_statement(false); break;
10166         case T___leave:   statement = parse_leave_statement();         break;
10167         case T___try:     statement = parse_ms_try_statment();         break;
10168         case T_asm:       statement = parse_asm_statement();           break;
10169         case T_break:     statement = parse_break();                   break;
10170         case T_case:      statement = parse_case_statement();          break;
10171         case T_continue:  statement = parse_continue();                break;
10172         case T_default:   statement = parse_default_statement();       break;
10173         case T_do:        statement = parse_do();                      break;
10174         case T_for:       statement = parse_for();                     break;
10175         case T_goto:      statement = parse_goto();                    break;
10176         case T_if:        statement = parse_if();                      break;
10177         case T_return:    statement = parse_return();                  break;
10178         case T_switch:    statement = parse_switch();                  break;
10179         case T_while:     statement = parse_while();                   break;
10180
10181         EXPRESSION_START
10182                 statement = parse_expression_statement();
10183                 break;
10184
10185         default:
10186                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10187                 statement = create_invalid_statement();
10188                 if (!at_anchor())
10189                         next_token();
10190                 break;
10191         }
10192         rem_anchor_token(';');
10193
10194         assert(statement != NULL
10195                         && statement->base.source_position.input_name != NULL);
10196
10197         return statement;
10198 }
10199
10200 /**
10201  * parse a statement and emits "statement has no effect" warning if needed
10202  * (This is really a wrapper around intern_parse_statement with check for 1
10203  *  single warning. It is needed, because for statement expressions we have
10204  *  to avoid the warning on the last statement)
10205  */
10206 static statement_t *parse_statement(void)
10207 {
10208         statement_t *statement = intern_parse_statement();
10209
10210         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10211                 expression_t *expression = statement->expression.expression;
10212                 if (!expression_has_effect(expression)) {
10213                         warningf(&expression->base.source_position,
10214                                         "statement has no effect");
10215                 }
10216         }
10217
10218         return statement;
10219 }
10220
10221 /**
10222  * Parse a compound statement.
10223  */
10224 static statement_t *parse_compound_statement(bool inside_expression_statement)
10225 {
10226         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10227
10228         PUSH_PARENT(statement);
10229
10230         eat('{');
10231         add_anchor_token('}');
10232         /* tokens, which can start a statement */
10233         /* TODO MS, __builtin_FOO */
10234         add_anchor_token('!');
10235         add_anchor_token('&');
10236         add_anchor_token('(');
10237         add_anchor_token('*');
10238         add_anchor_token('+');
10239         add_anchor_token('-');
10240         add_anchor_token('{');
10241         add_anchor_token('~');
10242         add_anchor_token(T_CHARACTER_CONSTANT);
10243         add_anchor_token(T_COLONCOLON);
10244         add_anchor_token(T_FLOATINGPOINT);
10245         add_anchor_token(T_IDENTIFIER);
10246         add_anchor_token(T_INTEGER);
10247         add_anchor_token(T_MINUSMINUS);
10248         add_anchor_token(T_PLUSPLUS);
10249         add_anchor_token(T_STRING_LITERAL);
10250         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10251         add_anchor_token(T_WIDE_STRING_LITERAL);
10252         add_anchor_token(T__Bool);
10253         add_anchor_token(T__Complex);
10254         add_anchor_token(T__Imaginary);
10255         add_anchor_token(T___FUNCTION__);
10256         add_anchor_token(T___PRETTY_FUNCTION__);
10257         add_anchor_token(T___alignof__);
10258         add_anchor_token(T___attribute__);
10259         add_anchor_token(T___builtin_va_start);
10260         add_anchor_token(T___extension__);
10261         add_anchor_token(T___func__);
10262         add_anchor_token(T___imag__);
10263         add_anchor_token(T___label__);
10264         add_anchor_token(T___real__);
10265         add_anchor_token(T___thread);
10266         add_anchor_token(T_asm);
10267         add_anchor_token(T_auto);
10268         add_anchor_token(T_bool);
10269         add_anchor_token(T_break);
10270         add_anchor_token(T_case);
10271         add_anchor_token(T_char);
10272         add_anchor_token(T_class);
10273         add_anchor_token(T_const);
10274         add_anchor_token(T_const_cast);
10275         add_anchor_token(T_continue);
10276         add_anchor_token(T_default);
10277         add_anchor_token(T_delete);
10278         add_anchor_token(T_double);
10279         add_anchor_token(T_do);
10280         add_anchor_token(T_dynamic_cast);
10281         add_anchor_token(T_enum);
10282         add_anchor_token(T_extern);
10283         add_anchor_token(T_false);
10284         add_anchor_token(T_float);
10285         add_anchor_token(T_for);
10286         add_anchor_token(T_goto);
10287         add_anchor_token(T_if);
10288         add_anchor_token(T_inline);
10289         add_anchor_token(T_int);
10290         add_anchor_token(T_long);
10291         add_anchor_token(T_new);
10292         add_anchor_token(T_operator);
10293         add_anchor_token(T_register);
10294         add_anchor_token(T_reinterpret_cast);
10295         add_anchor_token(T_restrict);
10296         add_anchor_token(T_return);
10297         add_anchor_token(T_short);
10298         add_anchor_token(T_signed);
10299         add_anchor_token(T_sizeof);
10300         add_anchor_token(T_static);
10301         add_anchor_token(T_static_cast);
10302         add_anchor_token(T_struct);
10303         add_anchor_token(T_switch);
10304         add_anchor_token(T_template);
10305         add_anchor_token(T_this);
10306         add_anchor_token(T_throw);
10307         add_anchor_token(T_true);
10308         add_anchor_token(T_try);
10309         add_anchor_token(T_typedef);
10310         add_anchor_token(T_typeid);
10311         add_anchor_token(T_typename);
10312         add_anchor_token(T_typeof);
10313         add_anchor_token(T_union);
10314         add_anchor_token(T_unsigned);
10315         add_anchor_token(T_using);
10316         add_anchor_token(T_void);
10317         add_anchor_token(T_volatile);
10318         add_anchor_token(T_wchar_t);
10319         add_anchor_token(T_while);
10320
10321         size_t const  top       = environment_top();
10322         scope_t      *old_scope = scope_push(&statement->compound.scope);
10323
10324         statement_t **anchor            = &statement->compound.statements;
10325         bool          only_decls_so_far = true;
10326         while (token.type != '}') {
10327                 if (token.type == T_EOF) {
10328                         errorf(&statement->base.source_position,
10329                                "EOF while parsing compound statement");
10330                         break;
10331                 }
10332                 statement_t *sub_statement = intern_parse_statement();
10333                 if (is_invalid_statement(sub_statement)) {
10334                         /* an error occurred. if we are at an anchor, return */
10335                         if (at_anchor())
10336                                 goto end_error;
10337                         continue;
10338                 }
10339
10340                 if (warning.declaration_after_statement) {
10341                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10342                                 only_decls_so_far = false;
10343                         } else if (!only_decls_so_far) {
10344                                 warningf(&sub_statement->base.source_position,
10345                                          "ISO C90 forbids mixed declarations and code");
10346                         }
10347                 }
10348
10349                 *anchor = sub_statement;
10350
10351                 while (sub_statement->base.next != NULL)
10352                         sub_statement = sub_statement->base.next;
10353
10354                 anchor = &sub_statement->base.next;
10355         }
10356         next_token();
10357
10358         /* look over all statements again to produce no effect warnings */
10359         if (warning.unused_value) {
10360                 statement_t *sub_statement = statement->compound.statements;
10361                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10362                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10363                                 continue;
10364                         /* don't emit a warning for the last expression in an expression
10365                          * statement as it has always an effect */
10366                         if (inside_expression_statement && sub_statement->base.next == NULL)
10367                                 continue;
10368
10369                         expression_t *expression = sub_statement->expression.expression;
10370                         if (!expression_has_effect(expression)) {
10371                                 warningf(&expression->base.source_position,
10372                                          "statement has no effect");
10373                         }
10374                 }
10375         }
10376
10377 end_error:
10378         rem_anchor_token(T_while);
10379         rem_anchor_token(T_wchar_t);
10380         rem_anchor_token(T_volatile);
10381         rem_anchor_token(T_void);
10382         rem_anchor_token(T_using);
10383         rem_anchor_token(T_unsigned);
10384         rem_anchor_token(T_union);
10385         rem_anchor_token(T_typeof);
10386         rem_anchor_token(T_typename);
10387         rem_anchor_token(T_typeid);
10388         rem_anchor_token(T_typedef);
10389         rem_anchor_token(T_try);
10390         rem_anchor_token(T_true);
10391         rem_anchor_token(T_throw);
10392         rem_anchor_token(T_this);
10393         rem_anchor_token(T_template);
10394         rem_anchor_token(T_switch);
10395         rem_anchor_token(T_struct);
10396         rem_anchor_token(T_static_cast);
10397         rem_anchor_token(T_static);
10398         rem_anchor_token(T_sizeof);
10399         rem_anchor_token(T_signed);
10400         rem_anchor_token(T_short);
10401         rem_anchor_token(T_return);
10402         rem_anchor_token(T_restrict);
10403         rem_anchor_token(T_reinterpret_cast);
10404         rem_anchor_token(T_register);
10405         rem_anchor_token(T_operator);
10406         rem_anchor_token(T_new);
10407         rem_anchor_token(T_long);
10408         rem_anchor_token(T_int);
10409         rem_anchor_token(T_inline);
10410         rem_anchor_token(T_if);
10411         rem_anchor_token(T_goto);
10412         rem_anchor_token(T_for);
10413         rem_anchor_token(T_float);
10414         rem_anchor_token(T_false);
10415         rem_anchor_token(T_extern);
10416         rem_anchor_token(T_enum);
10417         rem_anchor_token(T_dynamic_cast);
10418         rem_anchor_token(T_do);
10419         rem_anchor_token(T_double);
10420         rem_anchor_token(T_delete);
10421         rem_anchor_token(T_default);
10422         rem_anchor_token(T_continue);
10423         rem_anchor_token(T_const_cast);
10424         rem_anchor_token(T_const);
10425         rem_anchor_token(T_class);
10426         rem_anchor_token(T_char);
10427         rem_anchor_token(T_case);
10428         rem_anchor_token(T_break);
10429         rem_anchor_token(T_bool);
10430         rem_anchor_token(T_auto);
10431         rem_anchor_token(T_asm);
10432         rem_anchor_token(T___thread);
10433         rem_anchor_token(T___real__);
10434         rem_anchor_token(T___label__);
10435         rem_anchor_token(T___imag__);
10436         rem_anchor_token(T___func__);
10437         rem_anchor_token(T___extension__);
10438         rem_anchor_token(T___builtin_va_start);
10439         rem_anchor_token(T___attribute__);
10440         rem_anchor_token(T___alignof__);
10441         rem_anchor_token(T___PRETTY_FUNCTION__);
10442         rem_anchor_token(T___FUNCTION__);
10443         rem_anchor_token(T__Imaginary);
10444         rem_anchor_token(T__Complex);
10445         rem_anchor_token(T__Bool);
10446         rem_anchor_token(T_WIDE_STRING_LITERAL);
10447         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10448         rem_anchor_token(T_STRING_LITERAL);
10449         rem_anchor_token(T_PLUSPLUS);
10450         rem_anchor_token(T_MINUSMINUS);
10451         rem_anchor_token(T_INTEGER);
10452         rem_anchor_token(T_IDENTIFIER);
10453         rem_anchor_token(T_FLOATINGPOINT);
10454         rem_anchor_token(T_COLONCOLON);
10455         rem_anchor_token(T_CHARACTER_CONSTANT);
10456         rem_anchor_token('~');
10457         rem_anchor_token('{');
10458         rem_anchor_token('-');
10459         rem_anchor_token('+');
10460         rem_anchor_token('*');
10461         rem_anchor_token('(');
10462         rem_anchor_token('&');
10463         rem_anchor_token('!');
10464         rem_anchor_token('}');
10465         assert(current_scope == &statement->compound.scope);
10466         scope_pop(old_scope);
10467         environment_pop_to(top);
10468
10469         POP_PARENT;
10470         return statement;
10471 }
10472
10473 /**
10474  * Check for unused global static functions and variables
10475  */
10476 static void check_unused_globals(void)
10477 {
10478         if (!warning.unused_function && !warning.unused_variable)
10479                 return;
10480
10481         for (const entity_t *entity = file_scope->entities; entity != NULL;
10482              entity = entity->base.next) {
10483                 if (!is_declaration(entity))
10484                         continue;
10485
10486                 const declaration_t *declaration = &entity->declaration;
10487                 if (declaration->used                  ||
10488                     declaration->modifiers & DM_UNUSED ||
10489                     declaration->modifiers & DM_USED   ||
10490                     declaration->storage_class != STORAGE_CLASS_STATIC)
10491                         continue;
10492
10493                 const char *s;
10494                 if (entity->kind == ENTITY_FUNCTION) {
10495                         /* inhibit warning for static inline functions */
10496                         if (entity->function.is_inline)
10497                                 continue;
10498
10499                         s = entity->function.statement != NULL ? "defined" : "declared";
10500                 } else {
10501                         s = "defined";
10502                 }
10503
10504                 warningf(&declaration->base.source_position, "'%#N' %s but not used", entity);
10505         }
10506 }
10507
10508 static void parse_global_asm(void)
10509 {
10510         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10511
10512         eat(T_asm);
10513         expect('(', end_error);
10514
10515         statement->asms.asm_text = parse_string_literals();
10516         statement->base.next     = unit->global_asm;
10517         unit->global_asm         = statement;
10518
10519         expect(')', end_error);
10520         expect(';', end_error);
10521
10522 end_error:;
10523 }
10524
10525 static void parse_linkage_specification(void)
10526 {
10527         eat(T_extern);
10528
10529         source_position_t const pos     = *HERE;
10530         char const       *const linkage = parse_string_literals().begin;
10531
10532         linkage_kind_t old_linkage = current_linkage;
10533         linkage_kind_t new_linkage;
10534         if (strcmp(linkage, "C") == 0) {
10535                 new_linkage = LINKAGE_C;
10536         } else if (strcmp(linkage, "C++") == 0) {
10537                 new_linkage = LINKAGE_CXX;
10538         } else {
10539                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10540                 new_linkage = LINKAGE_INVALID;
10541         }
10542         current_linkage = new_linkage;
10543
10544         if (next_if('{')) {
10545                 parse_externals();
10546                 expect('}', end_error);
10547         } else {
10548                 parse_external();
10549         }
10550
10551 end_error:
10552         assert(current_linkage == new_linkage);
10553         current_linkage = old_linkage;
10554 }
10555
10556 static void parse_external(void)
10557 {
10558         switch (token.type) {
10559                 DECLARATION_START_NO_EXTERN
10560                 case T_IDENTIFIER:
10561                 case T___extension__:
10562                 /* tokens below are for implicit int */
10563                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10564                              implicit int) */
10565                 case '*': /* * x; -> int* x; */
10566                 case '(': /* (x); -> int (x); */
10567                         parse_external_declaration();
10568                         return;
10569
10570                 case T_extern:
10571                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10572                                 parse_linkage_specification();
10573                         } else {
10574                                 parse_external_declaration();
10575                         }
10576                         return;
10577
10578                 case T_asm:
10579                         parse_global_asm();
10580                         return;
10581
10582                 case T_namespace:
10583                         parse_namespace_definition();
10584                         return;
10585
10586                 case ';':
10587                         if (!strict_mode) {
10588                                 if (warning.other)
10589                                         warningf(HERE, "stray ';' outside of function");
10590                                 next_token();
10591                                 return;
10592                         }
10593                         /* FALLTHROUGH */
10594
10595                 default:
10596                         errorf(HERE, "stray %K outside of function", &token);
10597                         if (token.type == '(' || token.type == '{' || token.type == '[')
10598                                 eat_until_matching_token(token.type);
10599                         next_token();
10600                         return;
10601         }
10602 }
10603
10604 static void parse_externals(void)
10605 {
10606         add_anchor_token('}');
10607         add_anchor_token(T_EOF);
10608
10609 #ifndef NDEBUG
10610         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10611         unsigned char token_anchor_copy[T_LAST_TOKEN];
10612         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10613 #endif
10614
10615         while (token.type != T_EOF && token.type != '}') {
10616 #ifndef NDEBUG
10617                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10618                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10619                         if (count != 0) {
10620                                 /* the anchor set and its copy differs */
10621                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10622                         }
10623                 }
10624                 if (in_gcc_extension) {
10625                         /* an gcc extension scope was not closed */
10626                         internal_errorf(HERE, "Leaked __extension__");
10627                 }
10628 #endif
10629
10630                 parse_external();
10631         }
10632
10633         rem_anchor_token(T_EOF);
10634         rem_anchor_token('}');
10635 }
10636
10637 /**
10638  * Parse a translation unit.
10639  */
10640 static void parse_translation_unit(void)
10641 {
10642         add_anchor_token(T_EOF);
10643
10644         while (true) {
10645                 parse_externals();
10646
10647                 if (token.type == T_EOF)
10648                         break;
10649
10650                 errorf(HERE, "stray %K outside of function", &token);
10651                 if (token.type == '(' || token.type == '{' || token.type == '[')
10652                         eat_until_matching_token(token.type);
10653                 next_token();
10654         }
10655 }
10656
10657 void set_default_visibility(elf_visibility_tag_t visibility)
10658 {
10659         default_visibility = visibility;
10660 }
10661
10662 /**
10663  * Parse the input.
10664  *
10665  * @return  the translation unit or NULL if errors occurred.
10666  */
10667 void start_parsing(void)
10668 {
10669         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10670         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10671         diagnostic_count  = 0;
10672         error_count       = 0;
10673         warning_count     = 0;
10674
10675         print_to_file(stderr);
10676
10677         assert(unit == NULL);
10678         unit = allocate_ast_zero(sizeof(unit[0]));
10679
10680         assert(file_scope == NULL);
10681         file_scope = &unit->scope;
10682
10683         assert(current_scope == NULL);
10684         scope_push(&unit->scope);
10685
10686         create_gnu_builtins();
10687         if (c_mode & _MS)
10688                 create_microsoft_intrinsics();
10689 }
10690
10691 translation_unit_t *finish_parsing(void)
10692 {
10693         assert(current_scope == &unit->scope);
10694         scope_pop(NULL);
10695
10696         assert(file_scope == &unit->scope);
10697         check_unused_globals();
10698         file_scope = NULL;
10699
10700         DEL_ARR_F(environment_stack);
10701         DEL_ARR_F(label_stack);
10702
10703         translation_unit_t *result = unit;
10704         unit = NULL;
10705         return result;
10706 }
10707
10708 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10709  * are given length one. */
10710 static void complete_incomplete_arrays(void)
10711 {
10712         size_t n = ARR_LEN(incomplete_arrays);
10713         for (size_t i = 0; i != n; ++i) {
10714                 declaration_t *const decl = incomplete_arrays[i];
10715                 type_t        *const type = skip_typeref(decl->type);
10716
10717                 if (!is_type_incomplete(type))
10718                         continue;
10719
10720                 if (warning.other) {
10721                         source_position_t const *const pos = &decl->base.source_position;
10722                         warningf(pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10723                 }
10724
10725                 type_t *const new_type = duplicate_type(type);
10726                 new_type->array.size_constant     = true;
10727                 new_type->array.has_implicit_size = true;
10728                 new_type->array.size              = 1;
10729
10730                 type_t *const result = identify_new_type(new_type);
10731
10732                 decl->type = result;
10733         }
10734 }
10735
10736 void prepare_main_collect2(entity_t *entity)
10737 {
10738         // create call to __main
10739         symbol_t *symbol         = symbol_table_insert("__main");
10740         entity_t *subsubmain_ent
10741                 = create_implicit_function(symbol, &builtin_source_position);
10742
10743         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10744         type_t       *ftype       = subsubmain_ent->declaration.type;
10745         ref->base.source_position = builtin_source_position;
10746         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10747         ref->reference.entity     = subsubmain_ent;
10748
10749         expression_t *call = allocate_expression_zero(EXPR_CALL);
10750         call->base.source_position = builtin_source_position;
10751         call->base.type            = type_void;
10752         call->call.function        = ref;
10753
10754         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10755         expr_statement->base.source_position  = builtin_source_position;
10756         expr_statement->expression.expression = call;
10757
10758         statement_t *statement = entity->function.statement;
10759         assert(statement->kind == STATEMENT_COMPOUND);
10760         compound_statement_t *compounds = &statement->compound;
10761
10762         expr_statement->base.next = compounds->statements;
10763         compounds->statements     = expr_statement;
10764 }
10765
10766 void parse(void)
10767 {
10768         lookahead_bufpos = 0;
10769         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10770                 next_token();
10771         }
10772         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10773         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10774         parse_translation_unit();
10775         complete_incomplete_arrays();
10776         DEL_ARR_F(incomplete_arrays);
10777         incomplete_arrays = NULL;
10778 }
10779
10780 /**
10781  * Initialize the parser.
10782  */
10783 void init_parser(void)
10784 {
10785         sym_anonymous = symbol_table_insert("<anonymous>");
10786
10787         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10788
10789         init_expression_parsers();
10790         obstack_init(&temp_obst);
10791 }
10792
10793 /**
10794  * Terminate the parser.
10795  */
10796 void exit_parser(void)
10797 {
10798         obstack_free(&temp_obst, NULL);
10799 }