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 TYPENAME_START      \
 219         TYPE_QUALIFIERS         \
 220         TYPE_SPECIFIERS
 221
 222 #define EXPRESSION_START              \
 223         case '!':                         \
 224         case '&':                         \
 225         case '(':                         \
 226         case '*':                         \
 227         case '+':                         \
 228         case '-':                         \
 229         case '~':                         \
 230         case T_ANDAND:                    \
 231         case T_CHARACTER_CONSTANT:        \
 232         case T_FLOATINGPOINT:             \
 233         case T_FLOATINGPOINT_HEXADECIMAL: \
 234         case T_INTEGER:                   \
 235         case T_INTEGER_HEXADECIMAL:       \
 236         case T_INTEGER_OCTAL:             \
 237         case T_MINUSMINUS:                \
 238         case T_PLUSPLUS:                  \
 239         case T_STRING_LITERAL:            \
 240         case T_WIDE_CHARACTER_CONSTANT:   \
 241         case T_WIDE_STRING_LITERAL:       \
 242         case T___FUNCDNAME__:             \
 243         case T___FUNCSIG__:               \
 244         case T___FUNCTION__:              \
 245         case T___PRETTY_FUNCTION__:       \
 246         case T___alignof__:               \
 247         case T___builtin_classify_type:   \
 248         case T___builtin_constant_p:      \
 249         case T___builtin_isgreater:       \
 250         case T___builtin_isgreaterequal:  \
 251         case T___builtin_isless:          \
 252         case T___builtin_islessequal:     \
 253         case T___builtin_islessgreater:   \
 254         case T___builtin_isunordered:     \
 255         case T___builtin_offsetof:        \
 256         case T___builtin_va_arg:          \
 257         case T___builtin_va_copy:         \
 258         case T___builtin_va_start:        \
 259         case T___func__:                  \
 260         case T___noop:                    \
 261         case T__assume:                   \
 262         case T_delete:                    \
 263         case T_false:                     \
 264         case T_sizeof:                    \
 265         case T_throw:                     \
 266         case T_true:
 267
 268 /**
 269  * Returns the size of a statement node.
 270  *
 271  * @param kind  the statement kind
 272  */
 273 static size_t get_statement_struct_size(statement_kind_t kind)
 274 {
 275         static const size_t sizes[] = {
 276                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 277                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 278                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 279                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 280                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 281                 [STATEMENT_IF]          = sizeof(if_statement_t),
 282                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 283                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 284                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 285                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 286                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 287                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 288                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 289                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 290                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 291                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 292                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 293                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 294                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 295         };
 296         assert(kind < lengthof(sizes));
 297         assert(sizes[kind] != 0);
 298         return sizes[kind];
 299 }
 300
 301 /**
 302  * Returns the size of an expression node.
 303  *
 304  * @param kind  the expression kind
 305  */
 306 static size_t get_expression_struct_size(expression_kind_t kind)
 307 {
 308         static const size_t sizes[] = {
 309                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 310                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 311                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 312                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 313                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 314                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 315                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 316                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 317                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 318                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 319                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 320                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 321                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 322                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 323                 [EXPR_CALL]                       = sizeof(call_expression_t),
 324                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 325                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 326                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 327                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 328                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 329                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 330                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 331                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 332                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 333                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 334                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 335                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 336                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 337                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 338                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 339                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 340                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 341         };
 342         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 343                 return sizes[EXPR_UNARY_FIRST];
 344         }
 345         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 346                 return sizes[EXPR_BINARY_FIRST];
 347         }
 348         assert(kind < lengthof(sizes));
 349         assert(sizes[kind] != 0);
 350         return sizes[kind];
 351 }
 352
 353 /**
 354  * Allocate a statement node of given kind and initialize all
 355  * fields with zero. Sets its source position to the position
 356  * of the current token.
 357  */
 358 static statement_t *allocate_statement_zero(statement_kind_t kind)
 359 {
 360         size_t       size = get_statement_struct_size(kind);
 361         statement_t *res  = allocate_ast_zero(size);
 362
 363         res->base.kind            = kind;
 364         res->base.parent          = current_parent;
 365         res->base.source_position = token.source_position;
 366         return res;
 367 }
 368
 369 /**
 370  * Allocate an expression node of given kind and initialize all
 371  * fields with zero.
 372  *
 373  * @param kind  the kind of the expression to allocate
 374  */
 375 static expression_t *allocate_expression_zero(expression_kind_t kind)
 376 {
 377         size_t        size = get_expression_struct_size(kind);
 378         expression_t *res  = allocate_ast_zero(size);
 379
 380         res->base.kind            = kind;
 381         res->base.type            = type_error_type;
 382         res->base.source_position = token.source_position;
 383         return res;
 384 }
 385
 386 /**
 387  * Creates a new invalid expression at the source position
 388  * of the current token.
 389  */
 390 static expression_t *create_invalid_expression(void)
 391 {
 392         return allocate_expression_zero(EXPR_INVALID);
 393 }
 394
 395 /**
 396  * Creates a new invalid statement.
 397  */
 398 static statement_t *create_invalid_statement(void)
 399 {
 400         return allocate_statement_zero(STATEMENT_INVALID);
 401 }
 402
 403 /**
 404  * Allocate a new empty statement.
 405  */
 406 static statement_t *create_empty_statement(void)
 407 {
 408         return allocate_statement_zero(STATEMENT_EMPTY);
 409 }
 410
 411 static function_parameter_t *allocate_parameter(type_t *const type)
 412 {
 413         function_parameter_t *const param
 414                 = obstack_alloc(type_obst, sizeof(*param));
 415         memset(param, 0, sizeof(*param));
 416         param->type = type;
 417         return param;
 418 }
 419
 420 /**
 421  * Returns the size of an initializer node.
 422  *
 423  * @param kind  the initializer kind
 424  */
 425 static size_t get_initializer_size(initializer_kind_t kind)
 426 {
 427         static const size_t sizes[] = {
 428                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 429                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 430                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 431                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 432                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 433         };
 434         assert(kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate an initializer node of given kind and initialize all
 441  * fields with zero.
 442  */
 443 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 444 {
 445         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 446         result->kind          = kind;
 447
 448         return result;
 449 }
 450
 451 /**
 452  * Returns the index of the top element of the environment stack.
 453  */
 454 static size_t environment_top(void)
 455 {
 456         return ARR_LEN(environment_stack);
 457 }
 458
 459 /**
 460  * Returns the index of the top element of the global label stack.
 461  */
 462 static size_t label_top(void)
 463 {
 464         return ARR_LEN(label_stack);
 465 }
 466
 467 /**
 468  * Return the next token.
 469  */
 470 static inline void next_token(void)
 471 {
 472         token                              = lookahead_buffer[lookahead_bufpos];
 473         lookahead_buffer[lookahead_bufpos] = lexer_token;
 474         lexer_next_token();
 475
 476         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 477
 478 #ifdef PRINT_TOKENS
 479         print_token(stderr, &token);
 480         fprintf(stderr, "\n");
 481 #endif
 482 }
 483
 484 static inline bool next_if(int const type)
 485 {
 486         if (token.type == type) {
 487                 next_token();
 488                 return true;
 489         } else {
 490                 return false;
 491         }
 492 }
 493
 494 /**
 495  * Return the next token with a given lookahead.
 496  */
 497 static inline const token_t *look_ahead(size_t num)
 498 {
 499         assert(0 < num && num <= MAX_LOOKAHEAD);
 500         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 501         return &lookahead_buffer[pos];
 502 }
 503
 504 /**
 505  * Adds a token type to the token type anchor set (a multi-set).
 506  */
 507 static void add_anchor_token(int token_type)
 508 {
 509         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 510         ++token_anchor_set[token_type];
 511 }
 512
 513 /**
 514  * Set the number of tokens types of the given type
 515  * to zero and return the old count.
 516  */
 517 static int save_and_reset_anchor_state(int token_type)
 518 {
 519         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 520         int count = token_anchor_set[token_type];
 521         token_anchor_set[token_type] = 0;
 522         return count;
 523 }
 524
 525 /**
 526  * Restore the number of token types to the given count.
 527  */
 528 static void restore_anchor_state(int token_type, int count)
 529 {
 530         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 531         token_anchor_set[token_type] = count;
 532 }
 533
 534 /**
 535  * Remove a token type from the token type anchor set (a multi-set).
 536  */
 537 static void rem_anchor_token(int token_type)
 538 {
 539         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 540         assert(token_anchor_set[token_type] != 0);
 541         --token_anchor_set[token_type];
 542 }
 543
 544 /**
 545  * Return true if the token type of the current token is
 546  * in the anchor set.
 547  */
 548 static bool at_anchor(void)
 549 {
 550         if (token.type < 0)
 551                 return false;
 552         return token_anchor_set[token.type];
 553 }
 554
 555 /**
 556  * Eat tokens until a matching token type is found.
 557  */
 558 static void eat_until_matching_token(int type)
 559 {
 560         int end_token;
 561         switch (type) {
 562                 case '(': end_token = ')';  break;
 563                 case '{': end_token = '}';  break;
 564                 case '[': end_token = ']';  break;
 565                 default:  end_token = type; break;
 566         }
 567
 568         unsigned parenthesis_count = 0;
 569         unsigned brace_count       = 0;
 570         unsigned bracket_count     = 0;
 571         while (token.type        != end_token ||
 572                parenthesis_count != 0         ||
 573                brace_count       != 0         ||
 574                bracket_count     != 0) {
 575                 switch (token.type) {
 576                 case T_EOF: return;
 577                 case '(': ++parenthesis_count; break;
 578                 case '{': ++brace_count;       break;
 579                 case '[': ++bracket_count;     break;
 580
 581                 case ')':
 582                         if (parenthesis_count > 0)
 583                                 --parenthesis_count;
 584                         goto check_stop;
 585
 586                 case '}':
 587                         if (brace_count > 0)
 588                                 --brace_count;
 589                         goto check_stop;
 590
 591                 case ']':
 592                         if (bracket_count > 0)
 593                                 --bracket_count;
 594 check_stop:
 595                         if (token.type        == end_token &&
 596                             parenthesis_count == 0         &&
 597                             brace_count       == 0         &&
 598                             bracket_count     == 0)
 599                                 return;
 600                         break;
 601
 602                 default:
 603                         break;
 604                 }
 605                 next_token();
 606         }
 607 }
 608
 609 /**
 610  * Eat input tokens until an anchor is found.
 611  */
 612 static void eat_until_anchor(void)
 613 {
 614         while (token_anchor_set[token.type] == 0) {
 615                 if (token.type == '(' || token.type == '{' || token.type == '[')
 616                         eat_until_matching_token(token.type);
 617                 next_token();
 618         }
 619 }
 620
 621 /**
 622  * Eat a whole block from input tokens.
 623  */
 624 static void eat_block(void)
 625 {
 626         eat_until_matching_token('{');
 627         next_if('}');
 628 }
 629
 630 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 631
 632 /**
 633  * Report a parse error because an expected token was not found.
 634  */
 635 static
 636 #if defined __GNUC__ && __GNUC__ >= 4
 637 __attribute__((sentinel))
 638 #endif
 639 void parse_error_expected(const char *message, ...)
 640 {
 641         if (message != NULL) {
 642                 errorf(HERE, "%s", message);
 643         }
 644         va_list ap;
 645         va_start(ap, message);
 646         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 647         va_end(ap);
 648 }
 649
 650 /**
 651  * Report an incompatible type.
 652  */
 653 static void type_error_incompatible(const char *msg,
 654                 const source_position_t *source_position, type_t *type1, type_t *type2)
 655 {
 656         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 657                msg, type1, type2);
 658 }
 659
 660 /**
 661  * Expect the current token is the expected token.
 662  * If not, generate an error, eat the current statement,
 663  * and goto the error_label label.
 664  */
 665 #define expect(expected, error_label)                     \
 666         do {                                                  \
 667                 if (UNLIKELY(token.type != (expected))) {         \
 668                         parse_error_expected(NULL, (expected), NULL); \
 669                         add_anchor_token(expected);                   \
 670                         eat_until_anchor();                           \
 671                         next_if((expected));                          \
 672                         rem_anchor_token(expected);                   \
 673                         goto error_label;                             \
 674                 }                                                 \
 675                 next_token();                                     \
 676         } while (0)
 677
 678 /**
 679  * Push a given scope on the scope stack and make it the
 680  * current scope
 681  */
 682 static scope_t *scope_push(scope_t *new_scope)
 683 {
 684         if (current_scope != NULL) {
 685                 new_scope->depth = current_scope->depth + 1;
 686         }
 687
 688         scope_t *old_scope = current_scope;
 689         current_scope      = new_scope;
 690         return old_scope;
 691 }
 692
 693 /**
 694  * Pop the current scope from the scope stack.
 695  */
 696 static void scope_pop(scope_t *old_scope)
 697 {
 698         current_scope = old_scope;
 699 }
 700
 701 /**
 702  * Search an entity by its symbol in a given namespace.
 703  */
 704 static entity_t *get_entity(const symbol_t *const symbol,
 705                             namespace_tag_t namespc)
 706 {
 707         assert(namespc != NAMESPACE_INVALID);
 708         entity_t *entity = symbol->entity;
 709         for (; entity != NULL; entity = entity->base.symbol_next) {
 710                 if (entity->base.namespc == namespc)
 711                         return entity;
 712         }
 713
 714         return NULL;
 715 }
 716
 717 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 718  * possible. */
 719 static entity_t *get_tag(symbol_t const *const symbol,
 720                          entity_kind_tag_t const kind)
 721 {
 722         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 723         if (entity != NULL && entity->kind != kind) {
 724                 errorf(HERE,
 725                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 726                                 symbol, &entity->base.source_position);
 727                 entity = NULL;
 728         }
 729         return entity;
 730 }
 731
 732 /**
 733  * pushs an entity on the environment stack and links the corresponding symbol
 734  * it.
 735  */
 736 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 737 {
 738         symbol_t           *symbol  = entity->base.symbol;
 739         entity_namespace_t  namespc = entity->base.namespc;
 740         assert(namespc != NAMESPACE_INVALID);
 741
 742         /* replace/add entity into entity list of the symbol */
 743         entity_t **anchor;
 744         entity_t  *iter;
 745         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 746                 iter = *anchor;
 747                 if (iter == NULL)
 748                         break;
 749
 750                 /* replace an entry? */
 751                 if (iter->base.namespc == namespc) {
 752                         entity->base.symbol_next = iter->base.symbol_next;
 753                         break;
 754                 }
 755         }
 756         *anchor = entity;
 757
 758         /* remember old declaration */
 759         stack_entry_t entry;
 760         entry.symbol     = symbol;
 761         entry.old_entity = iter;
 762         entry.namespc    = namespc;
 763         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 764 }
 765
 766 /**
 767  * Push an entity on the environment stack.
 768  */
 769 static void environment_push(entity_t *entity)
 770 {
 771         assert(entity->base.source_position.input_name != NULL);
 772         assert(entity->base.parent_scope != NULL);
 773         stack_push(&environment_stack, entity);
 774 }
 775
 776 /**
 777  * Push a declaration on the global label stack.
 778  *
 779  * @param declaration  the declaration
 780  */
 781 static void label_push(entity_t *label)
 782 {
 783         /* we abuse the parameters scope as parent for the labels */
 784         label->base.parent_scope = &current_function->parameters;
 785         stack_push(&label_stack, label);
 786 }
 787
 788 /**
 789  * pops symbols from the environment stack until @p new_top is the top element
 790  */
 791 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 792 {
 793         stack_entry_t *stack = *stack_ptr;
 794         size_t         top   = ARR_LEN(stack);
 795         size_t         i;
 796
 797         assert(new_top <= top);
 798         if (new_top == top)
 799                 return;
 800
 801         for (i = top; i > new_top; --i) {
 802                 stack_entry_t *entry = &stack[i - 1];
 803
 804                 entity_t           *old_entity = entry->old_entity;
 805                 symbol_t           *symbol     = entry->symbol;
 806                 entity_namespace_t  namespc    = entry->namespc;
 807
 808                 /* replace with old_entity/remove */
 809                 entity_t **anchor;
 810                 entity_t  *iter;
 811                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 812                         iter = *anchor;
 813                         assert(iter != NULL);
 814                         /* replace an entry? */
 815                         if (iter->base.namespc == namespc)
 816                                 break;
 817                 }
 818
 819                 /* restore definition from outer scopes (if there was one) */
 820                 if (old_entity != NULL) {
 821                         old_entity->base.symbol_next = iter->base.symbol_next;
 822                         *anchor                      = old_entity;
 823                 } else {
 824                         /* remove entry from list */
 825                         *anchor = iter->base.symbol_next;
 826                 }
 827         }
 828
 829         ARR_SHRINKLEN(*stack_ptr, new_top);
 830 }
 831
 832 /**
 833  * Pop all entries from the environment stack until the new_top
 834  * is reached.
 835  *
 836  * @param new_top  the new stack top
 837  */
 838 static void environment_pop_to(size_t new_top)
 839 {
 840         stack_pop_to(&environment_stack, new_top);
 841 }
 842
 843 /**
 844  * Pop all entries from the global label stack until the new_top
 845  * is reached.
 846  *
 847  * @param new_top  the new stack top
 848  */
 849 static void label_pop_to(size_t new_top)
 850 {
 851         stack_pop_to(&label_stack, new_top);
 852 }
 853
 854 static int get_akind_rank(atomic_type_kind_t akind)
 855 {
 856         return (int) akind;
 857 }
 858
 859 /**
 860  * Return the type rank for an atomic type.
 861  */
 862 static int get_rank(const type_t *type)
 863 {
 864         assert(!is_typeref(type));
 865         if (type->kind == TYPE_ENUM)
 866                 return get_akind_rank(type->enumt.akind);
 867
 868         assert(type->kind == TYPE_ATOMIC);
 869         return get_akind_rank(type->atomic.akind);
 870 }
 871
 872 /**
 873  * §6.3.1.1:2  Do integer promotion for a given type.
 874  *
 875  * @param type  the type to promote
 876  * @return the promoted type
 877  */
 878 static type_t *promote_integer(type_t *type)
 879 {
 880         if (type->kind == TYPE_BITFIELD)
 881                 type = type->bitfield.base_type;
 882
 883         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 884                 type = type_int;
 885
 886         return type;
 887 }
 888
 889 /**
 890  * Create a cast expression.
 891  *
 892  * @param expression  the expression to cast
 893  * @param dest_type   the destination type
 894  */
 895 static expression_t *create_cast_expression(expression_t *expression,
 896                                             type_t *dest_type)
 897 {
 898         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 899
 900         cast->unary.value = expression;
 901         cast->base.type   = dest_type;
 902
 903         return cast;
 904 }
 905
 906 /**
 907  * Check if a given expression represents a null pointer constant.
 908  *
 909  * @param expression  the expression to check
 910  */
 911 static bool is_null_pointer_constant(const expression_t *expression)
 912 {
 913         /* skip void* cast */
 914         if (expression->kind == EXPR_UNARY_CAST ||
 915                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 916                 type_t *const type = skip_typeref(expression->base.type);
 917                 if (types_compatible(type, type_void_ptr))
 918                         expression = expression->unary.value;
 919         }
 920
 921         type_t *const type = skip_typeref(expression->base.type);
 922         if (!is_type_integer(type))
 923                 return false;
 924         switch (is_constant_expression(expression)) {
 925                 case EXPR_CLASS_ERROR:    return true;
 926                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 927                 default:                  return false;
 928         }
 929 }
 930
 931 /**
 932  * Create an implicit cast expression.
 933  *
 934  * @param expression  the expression to cast
 935  * @param dest_type   the destination type
 936  */
 937 static expression_t *create_implicit_cast(expression_t *expression,
 938                                           type_t *dest_type)
 939 {
 940         type_t *const source_type = expression->base.type;
 941
 942         if (source_type == dest_type)
 943                 return expression;
 944
 945         return create_cast_expression(expression, dest_type);
 946 }
 947
 948 typedef enum assign_error_t {
 949         ASSIGN_SUCCESS,
 950         ASSIGN_ERROR_INCOMPATIBLE,
 951         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 952         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 953         ASSIGN_WARNING_POINTER_FROM_INT,
 954         ASSIGN_WARNING_INT_FROM_POINTER
 955 } assign_error_t;
 956
 957 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
 958                                 const expression_t *const right,
 959                                 const char *context,
 960                                 const source_position_t *source_position)
 961 {
 962         type_t *const orig_type_right = right->base.type;
 963         type_t *const type_left       = skip_typeref(orig_type_left);
 964         type_t *const type_right      = skip_typeref(orig_type_right);
 965
 966         switch (error) {
 967         case ASSIGN_SUCCESS:
 968                 return;
 969         case ASSIGN_ERROR_INCOMPATIBLE:
 970                 errorf(source_position,
 971                        "destination type '%T' in %s is incompatible with type '%T'",
 972                        orig_type_left, context, orig_type_right);
 973                 return;
 974
 975         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 976                 if (warning.other) {
 977                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 978                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 979
 980                         /* the left type has all qualifiers from the right type */
 981                         unsigned missing_qualifiers
 982                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 983                         warningf(source_position,
 984                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
 985                                         orig_type_left, context, orig_type_right, missing_qualifiers);
 986                 }
 987                 return;
 988         }
 989
 990         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 991                 if (warning.other) {
 992                         warningf(source_position,
 993                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 994                                         orig_type_left, context, right, orig_type_right);
 995                 }
 996                 return;
 997
 998         case ASSIGN_WARNING_POINTER_FROM_INT:
 999                 if (warning.other) {
1000                         warningf(source_position,
1001                                         "%s makes pointer '%T' from integer '%T' without a cast",
1002                                         context, orig_type_left, orig_type_right);
1003                 }
1004                 return;
1005
1006         case ASSIGN_WARNING_INT_FROM_POINTER:
1007                 if (warning.other) {
1008                         warningf(source_position,
1009                                         "%s makes integer '%T' from pointer '%T' without a cast",
1010                                         context, orig_type_left, orig_type_right);
1011                 }
1012                 return;
1013
1014         default:
1015                 panic("invalid error value");
1016         }
1017 }
1018
1019 /** Implements the rules from §6.5.16.1 */
1020 static assign_error_t semantic_assign(type_t *orig_type_left,
1021                                       const expression_t *const right)
1022 {
1023         type_t *const orig_type_right = right->base.type;
1024         type_t *const type_left       = skip_typeref(orig_type_left);
1025         type_t *const type_right      = skip_typeref(orig_type_right);
1026
1027         if (is_type_pointer(type_left)) {
1028                 if (is_null_pointer_constant(right)) {
1029                         return ASSIGN_SUCCESS;
1030                 } else if (is_type_pointer(type_right)) {
1031                         type_t *points_to_left
1032                                 = skip_typeref(type_left->pointer.points_to);
1033                         type_t *points_to_right
1034                                 = skip_typeref(type_right->pointer.points_to);
1035                         assign_error_t res = ASSIGN_SUCCESS;
1036
1037                         /* the left type has all qualifiers from the right type */
1038                         unsigned missing_qualifiers
1039                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1040                         if (missing_qualifiers != 0) {
1041                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1042                         }
1043
1044                         points_to_left  = get_unqualified_type(points_to_left);
1045                         points_to_right = get_unqualified_type(points_to_right);
1046
1047                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1048                                 return res;
1049
1050                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1051                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1052                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1053                         }
1054
1055                         if (!types_compatible(points_to_left, points_to_right)) {
1056                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1057                         }
1058
1059                         return res;
1060                 } else if (is_type_integer(type_right)) {
1061                         return ASSIGN_WARNING_POINTER_FROM_INT;
1062                 }
1063         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1064                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1065                                 && is_type_pointer(type_right))) {
1066                 return ASSIGN_SUCCESS;
1067         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1068                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1069                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1070                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1071                         return ASSIGN_SUCCESS;
1072                 }
1073         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1074                 return ASSIGN_WARNING_INT_FROM_POINTER;
1075         }
1076
1077         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1078                 return ASSIGN_SUCCESS;
1079
1080         return ASSIGN_ERROR_INCOMPATIBLE;
1081 }
1082
1083 static expression_t *parse_constant_expression(void)
1084 {
1085         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1086
1087         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1088                 errorf(&result->base.source_position,
1089                        "expression '%E' is not constant", result);
1090         }
1091
1092         return result;
1093 }
1094
1095 static expression_t *parse_assignment_expression(void)
1096 {
1097         return parse_subexpression(PREC_ASSIGNMENT);
1098 }
1099
1100 static void warn_string_concat(const source_position_t *pos)
1101 {
1102         if (warning.traditional) {
1103                 warningf(pos, "traditional C rejects string constant concatenation");
1104         }
1105 }
1106
1107 static string_t parse_string_literals(void)
1108 {
1109         assert(token.type == T_STRING_LITERAL);
1110         string_t result = token.literal;
1111
1112         next_token();
1113
1114         while (token.type == T_STRING_LITERAL) {
1115                 warn_string_concat(&token.source_position);
1116                 result = concat_strings(&result, &token.literal);
1117                 next_token();
1118         }
1119
1120         return result;
1121 }
1122
1123 /**
1124  * compare two string, ignoring double underscores on the second.
1125  */
1126 static int strcmp_underscore(const char *s1, const char *s2)
1127 {
1128         if (s2[0] == '_' && s2[1] == '_') {
1129                 size_t len2 = strlen(s2);
1130                 size_t len1 = strlen(s1);
1131                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1132                         return strncmp(s1, s2+2, len2-4);
1133                 }
1134         }
1135
1136         return strcmp(s1, s2);
1137 }
1138
1139 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1140 {
1141         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1142         attribute->kind        = kind;
1143         return attribute;
1144 }
1145
1146 /**
1147  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1148  *
1149  *  attribute:
1150  *    __attribute__ ( ( attribute-list ) )
1151  *
1152  *  attribute-list:
1153  *    attrib
1154  *    attribute_list , attrib
1155  *
1156  *  attrib:
1157  *    empty
1158  *    any-word
1159  *    any-word ( identifier )
1160  *    any-word ( identifier , nonempty-expr-list )
1161  *    any-word ( expr-list )
1162  *
1163  *  where the "identifier" must not be declared as a type, and
1164  *  "any-word" may be any identifier (including one declared as a
1165  *  type), a reserved word storage class specifier, type specifier or
1166  *  type qualifier.  ??? This still leaves out most reserved keywords
1167  *  (following the old parser), shouldn't we include them, and why not
1168  *  allow identifiers declared as types to start the arguments?
1169  *
1170  *  Matze: this all looks confusing and little systematic, so we're even less
1171  *  strict and parse any list of things which are identifiers or
1172  *  (assignment-)expressions.
1173  */
1174 static attribute_argument_t *parse_attribute_arguments(void)
1175 {
1176         attribute_argument_t  *first  = NULL;
1177         attribute_argument_t **anchor = &first;
1178         if (token.type != ')') do {
1179                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1180
1181                 /* is it an identifier */
1182                 if (token.type == T_IDENTIFIER
1183                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1184                         symbol_t *symbol   = token.symbol;
1185                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1186                         argument->v.symbol = symbol;
1187                         next_token();
1188                 } else {
1189                         /* must be an expression */
1190                         expression_t *expression = parse_assignment_expression();
1191
1192                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1193                         argument->v.expression = expression;
1194                 }
1195
1196                 /* append argument */
1197                 *anchor = argument;
1198                 anchor  = &argument->next;
1199         } while (next_if(','));
1200         expect(')', end_error);
1201
1202         return first;
1203
1204 end_error:
1205         /* TODO... */
1206         return first;
1207 }
1208
1209 static attribute_t *parse_attribute_asm(void)
1210 {
1211         eat(T_asm);
1212
1213         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1214
1215         expect('(', end_error);
1216         attribute->a.arguments = parse_attribute_arguments();
1217         return attribute;
1218
1219 end_error:
1220         return NULL;
1221 }
1222
1223 static symbol_t *get_symbol_from_token(void)
1224 {
1225         switch(token.type) {
1226         case T_IDENTIFIER:
1227                 return token.symbol;
1228         case T_auto:
1229         case T_char:
1230         case T_double:
1231         case T_enum:
1232         case T_extern:
1233         case T_float:
1234         case T_int:
1235         case T_long:
1236         case T_register:
1237         case T_short:
1238         case T_static:
1239         case T_struct:
1240         case T_union:
1241         case T_unsigned:
1242         case T_void:
1243         case T_bool:
1244         case T__Bool:
1245         case T_class:
1246         case T_explicit:
1247         case T_export:
1248         case T_wchar_t:
1249         case T_const:
1250         case T_signed:
1251         case T___real__:
1252         case T___imag__:
1253         case T_restrict:
1254         case T_volatile:
1255         case T_inline:
1256                 /* maybe we need more tokens ... add them on demand */
1257                 return get_token_symbol(&token);
1258         default:
1259                 return NULL;
1260         }
1261 }
1262
1263 static attribute_t *parse_attribute_gnu_single(void)
1264 {
1265         /* parse "any-word" */
1266         symbol_t *symbol = get_symbol_from_token();
1267         if (symbol == NULL) {
1268                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1269                 return NULL;
1270         }
1271
1272         const char *name = symbol->string;
1273         next_token();
1274
1275         attribute_kind_t kind;
1276         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1277                 if (kind > ATTRIBUTE_GNU_LAST) {
1278                         if (warning.attribute) {
1279                                 warningf(HERE, "unknown attribute '%s' ignored", name);
1280                         }
1281                         /* TODO: we should still save the attribute in the list... */
1282                         kind = ATTRIBUTE_UNKNOWN;
1283                         break;
1284                 }
1285
1286                 const char *attribute_name = get_attribute_name(kind);
1287                 if (attribute_name != NULL
1288                                 && strcmp_underscore(attribute_name, name) == 0)
1289                         break;
1290         }
1291
1292         attribute_t *attribute = allocate_attribute_zero(kind);
1293
1294         /* parse arguments */
1295         if (next_if('('))
1296                 attribute->a.arguments = parse_attribute_arguments();
1297
1298         return attribute;
1299 }
1300
1301 static attribute_t *parse_attribute_gnu(void)
1302 {
1303         attribute_t  *first  = NULL;
1304         attribute_t **anchor = &first;
1305
1306         eat(T___attribute__);
1307         expect('(', end_error);
1308         expect('(', end_error);
1309
1310         if (token.type != ')') do {
1311                 attribute_t *attribute = parse_attribute_gnu_single();
1312                 if (attribute == NULL)
1313                         goto end_error;
1314
1315                 *anchor = attribute;
1316                 anchor  = &attribute->next;
1317         } while (next_if(','));
1318         expect(')', end_error);
1319         expect(')', end_error);
1320
1321 end_error:
1322         return first;
1323 }
1324
1325 /** Parse attributes. */
1326 static attribute_t *parse_attributes(attribute_t *first)
1327 {
1328         attribute_t **anchor = &first;
1329         for (;;) {
1330                 while (*anchor != NULL)
1331                         anchor = &(*anchor)->next;
1332
1333                 attribute_t *attribute;
1334                 switch (token.type) {
1335                 case T___attribute__:
1336                         attribute = parse_attribute_gnu();
1337                         if (attribute == NULL)
1338                                 continue;
1339                         break;
1340
1341                 case T_asm:
1342                         attribute = parse_attribute_asm();
1343                         break;
1344
1345                 case T_cdecl:
1346                         next_token();
1347                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1348                         break;
1349
1350                 case T__fastcall:
1351                         next_token();
1352                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1353                         break;
1354
1355                 case T__forceinline:
1356                         next_token();
1357                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1358                         break;
1359
1360                 case T__stdcall:
1361                         next_token();
1362                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1363                         break;
1364
1365                 case T___thiscall:
1366                         next_token();
1367                         /* TODO record modifier */
1368                         if (warning.other)
1369                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1370                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1371                         break;
1372
1373                 default:
1374                         return first;
1375                 }
1376
1377                 *anchor = attribute;
1378                 anchor  = &attribute->next;
1379         }
1380 }
1381
1382 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1383
1384 static entity_t *determine_lhs_ent(expression_t *const expr,
1385                                    entity_t *lhs_ent)
1386 {
1387         switch (expr->kind) {
1388                 case EXPR_REFERENCE: {
1389                         entity_t *const entity = expr->reference.entity;
1390                         /* we should only find variables as lvalues... */
1391                         if (entity->base.kind != ENTITY_VARIABLE
1392                                         && entity->base.kind != ENTITY_PARAMETER)
1393                                 return NULL;
1394
1395                         return entity;
1396                 }
1397
1398                 case EXPR_ARRAY_ACCESS: {
1399                         expression_t *const ref = expr->array_access.array_ref;
1400                         entity_t     *      ent = NULL;
1401                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1402                                 ent     = determine_lhs_ent(ref, lhs_ent);
1403                                 lhs_ent = ent;
1404                         } else {
1405                                 mark_vars_read(expr->select.compound, lhs_ent);
1406                         }
1407                         mark_vars_read(expr->array_access.index, lhs_ent);
1408                         return ent;
1409                 }
1410
1411                 case EXPR_SELECT: {
1412                         if (is_type_compound(skip_typeref(expr->base.type))) {
1413                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1414                         } else {
1415                                 mark_vars_read(expr->select.compound, lhs_ent);
1416                                 return NULL;
1417                         }
1418                 }
1419
1420                 case EXPR_UNARY_DEREFERENCE: {
1421                         expression_t *const val = expr->unary.value;
1422                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1423                                 /* *&x is a NOP */
1424                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1425                         } else {
1426                                 mark_vars_read(val, NULL);
1427                                 return NULL;
1428                         }
1429                 }
1430
1431                 default:
1432                         mark_vars_read(expr, NULL);
1433                         return NULL;
1434         }
1435 }
1436
1437 #define ENT_ANY ((entity_t*)-1)
1438
1439 /**
1440  * Mark declarations, which are read.  This is used to detect variables, which
1441  * are never read.
1442  * Example:
1443  * x = x + 1;
1444  *   x is not marked as "read", because it is only read to calculate its own new
1445  *   value.
1446  *
1447  * x += y; y += x;
1448  *   x and y are not detected as "not read", because multiple variables are
1449  *   involved.
1450  */
1451 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1452 {
1453         switch (expr->kind) {
1454                 case EXPR_REFERENCE: {
1455                         entity_t *const entity = expr->reference.entity;
1456                         if (entity->kind != ENTITY_VARIABLE
1457                                         && entity->kind != ENTITY_PARAMETER)
1458                                 return;
1459
1460                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1461                                 if (entity->kind == ENTITY_VARIABLE) {
1462                                         entity->variable.read = true;
1463                                 } else {
1464                                         entity->parameter.read = true;
1465                                 }
1466                         }
1467                         return;
1468                 }
1469
1470                 case EXPR_CALL:
1471                         // TODO respect pure/const
1472                         mark_vars_read(expr->call.function, NULL);
1473                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1474                                 mark_vars_read(arg->expression, NULL);
1475                         }
1476                         return;
1477
1478                 case EXPR_CONDITIONAL:
1479                         // TODO lhs_decl should depend on whether true/false have an effect
1480                         mark_vars_read(expr->conditional.condition, NULL);
1481                         if (expr->conditional.true_expression != NULL)
1482                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1483                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1484                         return;
1485
1486                 case EXPR_SELECT:
1487                         if (lhs_ent == ENT_ANY
1488                                         && !is_type_compound(skip_typeref(expr->base.type)))
1489                                 lhs_ent = NULL;
1490                         mark_vars_read(expr->select.compound, lhs_ent);
1491                         return;
1492
1493                 case EXPR_ARRAY_ACCESS: {
1494                         expression_t *const ref = expr->array_access.array_ref;
1495                         mark_vars_read(ref, lhs_ent);
1496                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1497                         mark_vars_read(expr->array_access.index, lhs_ent);
1498                         return;
1499                 }
1500
1501                 case EXPR_VA_ARG:
1502                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1503                         return;
1504
1505                 case EXPR_VA_COPY:
1506                         mark_vars_read(expr->va_copye.src, lhs_ent);
1507                         return;
1508
1509                 case EXPR_UNARY_CAST:
1510                         /* Special case: Use void cast to mark a variable as "read" */
1511                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1512                                 lhs_ent = NULL;
1513                         goto unary;
1514
1515
1516                 case EXPR_UNARY_THROW:
1517                         if (expr->unary.value == NULL)
1518                                 return;
1519                         /* FALLTHROUGH */
1520                 case EXPR_UNARY_DEREFERENCE:
1521                 case EXPR_UNARY_DELETE:
1522                 case EXPR_UNARY_DELETE_ARRAY:
1523                         if (lhs_ent == ENT_ANY)
1524                                 lhs_ent = NULL;
1525                         goto unary;
1526
1527                 case EXPR_UNARY_NEGATE:
1528                 case EXPR_UNARY_PLUS:
1529                 case EXPR_UNARY_BITWISE_NEGATE:
1530                 case EXPR_UNARY_NOT:
1531                 case EXPR_UNARY_TAKE_ADDRESS:
1532                 case EXPR_UNARY_POSTFIX_INCREMENT:
1533                 case EXPR_UNARY_POSTFIX_DECREMENT:
1534                 case EXPR_UNARY_PREFIX_INCREMENT:
1535                 case EXPR_UNARY_PREFIX_DECREMENT:
1536                 case EXPR_UNARY_CAST_IMPLICIT:
1537                 case EXPR_UNARY_ASSUME:
1538 unary:
1539                         mark_vars_read(expr->unary.value, lhs_ent);
1540                         return;
1541
1542                 case EXPR_BINARY_ADD:
1543                 case EXPR_BINARY_SUB:
1544                 case EXPR_BINARY_MUL:
1545                 case EXPR_BINARY_DIV:
1546                 case EXPR_BINARY_MOD:
1547                 case EXPR_BINARY_EQUAL:
1548                 case EXPR_BINARY_NOTEQUAL:
1549                 case EXPR_BINARY_LESS:
1550                 case EXPR_BINARY_LESSEQUAL:
1551                 case EXPR_BINARY_GREATER:
1552                 case EXPR_BINARY_GREATEREQUAL:
1553                 case EXPR_BINARY_BITWISE_AND:
1554                 case EXPR_BINARY_BITWISE_OR:
1555                 case EXPR_BINARY_BITWISE_XOR:
1556                 case EXPR_BINARY_LOGICAL_AND:
1557                 case EXPR_BINARY_LOGICAL_OR:
1558                 case EXPR_BINARY_SHIFTLEFT:
1559                 case EXPR_BINARY_SHIFTRIGHT:
1560                 case EXPR_BINARY_COMMA:
1561                 case EXPR_BINARY_ISGREATER:
1562                 case EXPR_BINARY_ISGREATEREQUAL:
1563                 case EXPR_BINARY_ISLESS:
1564                 case EXPR_BINARY_ISLESSEQUAL:
1565                 case EXPR_BINARY_ISLESSGREATER:
1566                 case EXPR_BINARY_ISUNORDERED:
1567                         mark_vars_read(expr->binary.left,  lhs_ent);
1568                         mark_vars_read(expr->binary.right, lhs_ent);
1569                         return;
1570
1571                 case EXPR_BINARY_ASSIGN:
1572                 case EXPR_BINARY_MUL_ASSIGN:
1573                 case EXPR_BINARY_DIV_ASSIGN:
1574                 case EXPR_BINARY_MOD_ASSIGN:
1575                 case EXPR_BINARY_ADD_ASSIGN:
1576                 case EXPR_BINARY_SUB_ASSIGN:
1577                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1578                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1579                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1580                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1581                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1582                         if (lhs_ent == ENT_ANY)
1583                                 lhs_ent = NULL;
1584                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1585                         mark_vars_read(expr->binary.right, lhs_ent);
1586                         return;
1587                 }
1588
1589                 case EXPR_VA_START:
1590                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1591                         return;
1592
1593                 EXPR_LITERAL_CASES
1594                 case EXPR_UNKNOWN:
1595                 case EXPR_INVALID:
1596                 case EXPR_STRING_LITERAL:
1597                 case EXPR_WIDE_STRING_LITERAL:
1598                 case EXPR_COMPOUND_LITERAL: // TODO init?
1599                 case EXPR_SIZEOF:
1600                 case EXPR_CLASSIFY_TYPE:
1601                 case EXPR_ALIGNOF:
1602                 case EXPR_FUNCNAME:
1603                 case EXPR_BUILTIN_CONSTANT_P:
1604                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1605                 case EXPR_OFFSETOF:
1606                 case EXPR_STATEMENT: // TODO
1607                 case EXPR_LABEL_ADDRESS:
1608                 case EXPR_REFERENCE_ENUM_VALUE:
1609                         return;
1610         }
1611
1612         panic("unhandled expression");
1613 }
1614
1615 static designator_t *parse_designation(void)
1616 {
1617         designator_t  *result = NULL;
1618         designator_t **anchor = &result;
1619
1620         for (;;) {
1621                 designator_t *designator;
1622                 switch (token.type) {
1623                 case '[':
1624                         designator = allocate_ast_zero(sizeof(designator[0]));
1625                         designator->source_position = token.source_position;
1626                         next_token();
1627                         add_anchor_token(']');
1628                         designator->array_index = parse_constant_expression();
1629                         rem_anchor_token(']');
1630                         expect(']', end_error);
1631                         break;
1632                 case '.':
1633                         designator = allocate_ast_zero(sizeof(designator[0]));
1634                         designator->source_position = token.source_position;
1635                         next_token();
1636                         if (token.type != T_IDENTIFIER) {
1637                                 parse_error_expected("while parsing designator",
1638                                                      T_IDENTIFIER, NULL);
1639                                 return NULL;
1640                         }
1641                         designator->symbol = token.symbol;
1642                         next_token();
1643                         break;
1644                 default:
1645                         expect('=', end_error);
1646                         return result;
1647                 }
1648
1649                 assert(designator != NULL);
1650                 *anchor = designator;
1651                 anchor  = &designator->next;
1652         }
1653 end_error:
1654         return NULL;
1655 }
1656
1657 static initializer_t *initializer_from_string(array_type_t *const type,
1658                                               const string_t *const string)
1659 {
1660         /* TODO: check len vs. size of array type */
1661         (void) type;
1662
1663         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1664         initializer->string.string = *string;
1665
1666         return initializer;
1667 }
1668
1669 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1670                                                    const string_t *const string)
1671 {
1672         /* TODO: check len vs. size of array type */
1673         (void) type;
1674
1675         initializer_t *const initializer =
1676                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1677         initializer->wide_string.string = *string;
1678
1679         return initializer;
1680 }
1681
1682 /**
1683  * Build an initializer from a given expression.
1684  */
1685 static initializer_t *initializer_from_expression(type_t *orig_type,
1686                                                   expression_t *expression)
1687 {
1688         /* TODO check that expression is a constant expression */
1689
1690         /* §6.7.8.14/15 char array may be initialized by string literals */
1691         type_t *type           = skip_typeref(orig_type);
1692         type_t *expr_type_orig = expression->base.type;
1693         type_t *expr_type      = skip_typeref(expr_type_orig);
1694
1695         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1696                 array_type_t *const array_type   = &type->array;
1697                 type_t       *const element_type = skip_typeref(array_type->element_type);
1698
1699                 if (element_type->kind == TYPE_ATOMIC) {
1700                         atomic_type_kind_t akind = element_type->atomic.akind;
1701                         switch (expression->kind) {
1702                         case EXPR_STRING_LITERAL:
1703                                 if (akind == ATOMIC_TYPE_CHAR
1704                                                 || akind == ATOMIC_TYPE_SCHAR
1705                                                 || akind == ATOMIC_TYPE_UCHAR) {
1706                                         return initializer_from_string(array_type,
1707                                                         &expression->string_literal.value);
1708                                 }
1709                                 break;
1710
1711                         case EXPR_WIDE_STRING_LITERAL: {
1712                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1713                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1714                                         return initializer_from_wide_string(array_type,
1715                                                         &expression->string_literal.value);
1716                                 }
1717                                 break;
1718                         }
1719
1720                         default:
1721                                 break;
1722                         }
1723                 }
1724         }
1725
1726         assign_error_t error = semantic_assign(type, expression);
1727         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1728                 return NULL;
1729         report_assign_error(error, type, expression, "initializer",
1730                             &expression->base.source_position);
1731
1732         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1733         result->value.value = create_implicit_cast(expression, type);
1734
1735         return result;
1736 }
1737
1738 /**
1739  * Checks if a given expression can be used as an constant initializer.
1740  */
1741 static bool is_initializer_constant(const expression_t *expression)
1742 {
1743         return
1744                 is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
1745                 is_address_constant(expression)    != EXPR_CLASS_VARIABLE;
1746 }
1747
1748 /**
1749  * Parses an scalar initializer.
1750  *
1751  * §6.7.8.11; eat {} without warning
1752  */
1753 static initializer_t *parse_scalar_initializer(type_t *type,
1754                                                bool must_be_constant)
1755 {
1756         /* there might be extra {} hierarchies */
1757         int braces = 0;
1758         if (token.type == '{') {
1759                 if (warning.other)
1760                         warningf(HERE, "extra curly braces around scalar initializer");
1761                 do {
1762                         eat('{');
1763                         ++braces;
1764                 } while (token.type == '{');
1765         }
1766
1767         expression_t *expression = parse_assignment_expression();
1768         mark_vars_read(expression, NULL);
1769         if (must_be_constant && !is_initializer_constant(expression)) {
1770                 errorf(&expression->base.source_position,
1771                        "initialisation expression '%E' is not constant",
1772                        expression);
1773         }
1774
1775         initializer_t *initializer = initializer_from_expression(type, expression);
1776
1777         if (initializer == NULL) {
1778                 errorf(&expression->base.source_position,
1779                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1780                        expression, expression->base.type, type);
1781                 /* TODO */
1782                 return NULL;
1783         }
1784
1785         bool additional_warning_displayed = false;
1786         while (braces > 0) {
1787                 next_if(',');
1788                 if (token.type != '}') {
1789                         if (!additional_warning_displayed && warning.other) {
1790                                 warningf(HERE, "additional elements in scalar initializer");
1791                                 additional_warning_displayed = true;
1792                         }
1793                 }
1794                 eat_block();
1795                 braces--;
1796         }
1797
1798         return initializer;
1799 }
1800
1801 /**
1802  * An entry in the type path.
1803  */
1804 typedef struct type_path_entry_t type_path_entry_t;
1805 struct type_path_entry_t {
1806         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1807         union {
1808                 size_t         index;          /**< For array types: the current index. */
1809                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1810         } v;
1811 };
1812
1813 /**
1814  * A type path expression a position inside compound or array types.
1815  */
1816 typedef struct type_path_t type_path_t;
1817 struct type_path_t {
1818         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1819         type_t            *top_type;     /**< type of the element the path points */
1820         size_t             max_index;    /**< largest index in outermost array */
1821 };
1822
1823 /**
1824  * Prints a type path for debugging.
1825  */
1826 static __attribute__((unused)) void debug_print_type_path(
1827                 const type_path_t *path)
1828 {
1829         size_t len = ARR_LEN(path->path);
1830
1831         for (size_t i = 0; i < len; ++i) {
1832                 const type_path_entry_t *entry = & path->path[i];
1833
1834                 type_t *type = skip_typeref(entry->type);
1835                 if (is_type_compound(type)) {
1836                         /* in gcc mode structs can have no members */
1837                         if (entry->v.compound_entry == NULL) {
1838                                 assert(i == len-1);
1839                                 continue;
1840                         }
1841                         fprintf(stderr, ".%s",
1842                                 entry->v.compound_entry->base.symbol->string);
1843                 } else if (is_type_array(type)) {
1844                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1845                 } else {
1846                         fprintf(stderr, "-INVALID-");
1847                 }
1848         }
1849         if (path->top_type != NULL) {
1850                 fprintf(stderr, "  (");
1851                 print_type(path->top_type);
1852                 fprintf(stderr, ")");
1853         }
1854 }
1855
1856 /**
1857  * Return the top type path entry, ie. in a path
1858  * (type).a.b returns the b.
1859  */
1860 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1861 {
1862         size_t len = ARR_LEN(path->path);
1863         assert(len > 0);
1864         return &path->path[len-1];
1865 }
1866
1867 /**
1868  * Enlarge the type path by an (empty) element.
1869  */
1870 static type_path_entry_t *append_to_type_path(type_path_t *path)
1871 {
1872         size_t len = ARR_LEN(path->path);
1873         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1874
1875         type_path_entry_t *result = & path->path[len];
1876         memset(result, 0, sizeof(result[0]));
1877         return result;
1878 }
1879
1880 /**
1881  * Descending into a sub-type. Enter the scope of the current top_type.
1882  */
1883 static void descend_into_subtype(type_path_t *path)
1884 {
1885         type_t *orig_top_type = path->top_type;
1886         type_t *top_type      = skip_typeref(orig_top_type);
1887
1888         type_path_entry_t *top = append_to_type_path(path);
1889         top->type              = top_type;
1890
1891         if (is_type_compound(top_type)) {
1892                 compound_t *compound  = top_type->compound.compound;
1893                 entity_t   *entry     = compound->members.entities;
1894
1895                 if (entry != NULL) {
1896                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
1897                         top->v.compound_entry = &entry->declaration;
1898                         path->top_type = entry->declaration.type;
1899                 } else {
1900                         path->top_type = NULL;
1901                 }
1902         } else if (is_type_array(top_type)) {
1903                 top->v.index   = 0;
1904                 path->top_type = top_type->array.element_type;
1905         } else {
1906                 assert(!is_type_valid(top_type));
1907         }
1908 }
1909
1910 /**
1911  * Pop an entry from the given type path, ie. returning from
1912  * (type).a.b to (type).a
1913  */
1914 static void ascend_from_subtype(type_path_t *path)
1915 {
1916         type_path_entry_t *top = get_type_path_top(path);
1917
1918         path->top_type = top->type;
1919
1920         size_t len = ARR_LEN(path->path);
1921         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1922 }
1923
1924 /**
1925  * Pop entries from the given type path until the given
1926  * path level is reached.
1927  */
1928 static void ascend_to(type_path_t *path, size_t top_path_level)
1929 {
1930         size_t len = ARR_LEN(path->path);
1931
1932         while (len > top_path_level) {
1933                 ascend_from_subtype(path);
1934                 len = ARR_LEN(path->path);
1935         }
1936 }
1937
1938 static bool walk_designator(type_path_t *path, const designator_t *designator,
1939                             bool used_in_offsetof)
1940 {
1941         for (; designator != NULL; designator = designator->next) {
1942                 type_path_entry_t *top       = get_type_path_top(path);
1943                 type_t            *orig_type = top->type;
1944
1945                 type_t *type = skip_typeref(orig_type);
1946
1947                 if (designator->symbol != NULL) {
1948                         symbol_t *symbol = designator->symbol;
1949                         if (!is_type_compound(type)) {
1950                                 if (is_type_valid(type)) {
1951                                         errorf(&designator->source_position,
1952                                                "'.%Y' designator used for non-compound type '%T'",
1953                                                symbol, orig_type);
1954                                 }
1955
1956                                 top->type             = type_error_type;
1957                                 top->v.compound_entry = NULL;
1958                                 orig_type             = type_error_type;
1959                         } else {
1960                                 compound_t *compound = type->compound.compound;
1961                                 entity_t   *iter     = compound->members.entities;
1962                                 for (; iter != NULL; iter = iter->base.next) {
1963                                         if (iter->base.symbol == symbol) {
1964                                                 break;
1965                                         }
1966                                 }
1967                                 if (iter == NULL) {
1968                                         errorf(&designator->source_position,
1969                                                "'%T' has no member named '%Y'", orig_type, symbol);
1970                                         return false;
1971                                 }
1972                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1973                                 if (used_in_offsetof) {
1974                                         type_t *real_type = skip_typeref(iter->declaration.type);
1975                                         if (real_type->kind == TYPE_BITFIELD) {
1976                                                 errorf(&designator->source_position,
1977                                                        "offsetof designator '%Y' must not specify bitfield",
1978                                                        symbol);
1979                                                 return false;
1980                                         }
1981                                 }
1982
1983                                 top->type             = orig_type;
1984                                 top->v.compound_entry = &iter->declaration;
1985                                 orig_type             = iter->declaration.type;
1986                         }
1987                 } else {
1988                         expression_t *array_index = designator->array_index;
1989                         assert(designator->array_index != NULL);
1990
1991                         if (!is_type_array(type)) {
1992                                 if (is_type_valid(type)) {
1993                                         errorf(&designator->source_position,
1994                                                "[%E] designator used for non-array type '%T'",
1995                                                array_index, orig_type);
1996                                 }
1997                                 return false;
1998                         }
1999
2000                         long index = fold_constant_to_int(array_index);
2001                         if (!used_in_offsetof) {
2002                                 if (index < 0) {
2003                                         errorf(&designator->source_position,
2004                                                "array index [%E] must be positive", array_index);
2005                                 } else if (type->array.size_constant) {
2006                                         long array_size = type->array.size;
2007                                         if (index >= array_size) {
2008                                                 errorf(&designator->source_position,
2009                                                        "designator [%E] (%d) exceeds array size %d",
2010                                                        array_index, index, array_size);
2011                                         }
2012                                 }
2013                         }
2014
2015                         top->type    = orig_type;
2016                         top->v.index = (size_t) index;
2017                         orig_type    = type->array.element_type;
2018                 }
2019                 path->top_type = orig_type;
2020
2021                 if (designator->next != NULL) {
2022                         descend_into_subtype(path);
2023                 }
2024         }
2025         return true;
2026 }
2027
2028 static void advance_current_object(type_path_t *path, size_t top_path_level)
2029 {
2030         type_path_entry_t *top = get_type_path_top(path);
2031
2032         type_t *type = skip_typeref(top->type);
2033         if (is_type_union(type)) {
2034                 /* in unions only the first element is initialized */
2035                 top->v.compound_entry = NULL;
2036         } else if (is_type_struct(type)) {
2037                 declaration_t *entry = top->v.compound_entry;
2038
2039                 entity_t *next_entity = entry->base.next;
2040                 if (next_entity != NULL) {
2041                         assert(is_declaration(next_entity));
2042                         entry = &next_entity->declaration;
2043                 } else {
2044                         entry = NULL;
2045                 }
2046
2047                 top->v.compound_entry = entry;
2048                 if (entry != NULL) {
2049                         path->top_type = entry->type;
2050                         return;
2051                 }
2052         } else if (is_type_array(type)) {
2053                 assert(is_type_array(type));
2054
2055                 top->v.index++;
2056
2057                 if (!type->array.size_constant || top->v.index < type->array.size) {
2058                         return;
2059                 }
2060         } else {
2061                 assert(!is_type_valid(type));
2062                 return;
2063         }
2064
2065         /* we're past the last member of the current sub-aggregate, try if we
2066          * can ascend in the type hierarchy and continue with another subobject */
2067         size_t len = ARR_LEN(path->path);
2068
2069         if (len > top_path_level) {
2070                 ascend_from_subtype(path);
2071                 advance_current_object(path, top_path_level);
2072         } else {
2073                 path->top_type = NULL;
2074         }
2075 }
2076
2077 /**
2078  * skip any {...} blocks until a closing bracket is reached.
2079  */
2080 static void skip_initializers(void)
2081 {
2082         next_if('{');
2083
2084         while (token.type != '}') {
2085                 if (token.type == T_EOF)
2086                         return;
2087                 if (token.type == '{') {
2088                         eat_block();
2089                         continue;
2090                 }
2091                 next_token();
2092         }
2093 }
2094
2095 static initializer_t *create_empty_initializer(void)
2096 {
2097         static initializer_t empty_initializer
2098                 = { .list = { { INITIALIZER_LIST }, 0 } };
2099         return &empty_initializer;
2100 }
2101
2102 /**
2103  * Parse a part of an initialiser for a struct or union,
2104  */
2105 static initializer_t *parse_sub_initializer(type_path_t *path,
2106                 type_t *outer_type, size_t top_path_level,
2107                 parse_initializer_env_t *env)
2108 {
2109         if (token.type == '}') {
2110                 /* empty initializer */
2111                 return create_empty_initializer();
2112         }
2113
2114         type_t *orig_type = path->top_type;
2115         type_t *type      = NULL;
2116
2117         if (orig_type == NULL) {
2118                 /* We are initializing an empty compound. */
2119         } else {
2120                 type = skip_typeref(orig_type);
2121         }
2122
2123         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2124
2125         while (true) {
2126                 designator_t *designator = NULL;
2127                 if (token.type == '.' || token.type == '[') {
2128                         designator = parse_designation();
2129                         goto finish_designator;
2130                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2131                         /* GNU-style designator ("identifier: value") */
2132                         designator = allocate_ast_zero(sizeof(designator[0]));
2133                         designator->source_position = token.source_position;
2134                         designator->symbol          = token.symbol;
2135                         eat(T_IDENTIFIER);
2136                         eat(':');
2137
2138 finish_designator:
2139                         /* reset path to toplevel, evaluate designator from there */
2140                         ascend_to(path, top_path_level);
2141                         if (!walk_designator(path, designator, false)) {
2142                                 /* can't continue after designation error */
2143                                 goto end_error;
2144                         }
2145
2146                         initializer_t *designator_initializer
2147                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2148                         designator_initializer->designator.designator = designator;
2149                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2150
2151                         orig_type = path->top_type;
2152                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2153                 }
2154
2155                 initializer_t *sub;
2156
2157                 if (token.type == '{') {
2158                         if (type != NULL && is_type_scalar(type)) {
2159                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2160                         } else {
2161                                 if (type == NULL) {
2162                                         if (env->entity != NULL) {
2163                                                 errorf(HERE,
2164                                                      "extra brace group at end of initializer for '%Y'",
2165                                                      env->entity->base.symbol);
2166                                         } else {
2167                                                 errorf(HERE, "extra brace group at end of initializer");
2168                                         }
2169                                         eat('{');
2170                                 } else {
2171                                         eat('{');
2172                                         descend_into_subtype(path);
2173                                 }
2174
2175                                 add_anchor_token('}');
2176                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2177                                                             env);
2178                                 rem_anchor_token('}');
2179
2180                                 if (type != NULL) {
2181                                         ascend_from_subtype(path);
2182                                         expect('}', end_error);
2183                                 } else {
2184                                         expect('}', end_error);
2185                                         goto error_parse_next;
2186                                 }
2187                         }
2188                 } else {
2189                         /* must be an expression */
2190                         expression_t *expression = parse_assignment_expression();
2191                         mark_vars_read(expression, NULL);
2192
2193                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2194                                 errorf(&expression->base.source_position,
2195                                        "Initialisation expression '%E' is not constant",
2196                                        expression);
2197                         }
2198
2199                         if (type == NULL) {
2200                                 /* we are already outside, ... */
2201                                 if (outer_type == NULL)
2202                                         goto error_parse_next;
2203                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2204                                 if (is_type_compound(outer_type_skip) &&
2205                                                 !outer_type_skip->compound.compound->complete) {
2206                                         goto error_parse_next;
2207                                 }
2208
2209                                 if (warning.other) {
2210                                         if (env->entity != NULL) {
2211                                                 warningf(HERE, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2212                                         } else {
2213                                                 warningf(HERE, "excess elements in initializer");
2214                                         }
2215                                 }
2216                                 goto error_parse_next;
2217                         }
2218
2219                         /* handle { "string" } special case */
2220                         if ((expression->kind == EXPR_STRING_LITERAL
2221                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2222                                         && outer_type != NULL) {
2223                                 sub = initializer_from_expression(outer_type, expression);
2224                                 if (sub != NULL) {
2225                                         next_if(',');
2226                                         if (token.type != '}' && warning.other) {
2227                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2228                                                                  orig_type);
2229                                         }
2230                                         /* TODO: eat , ... */
2231                                         return sub;
2232                                 }
2233                         }
2234
2235                         /* descend into subtypes until expression matches type */
2236                         while (true) {
2237                                 orig_type = path->top_type;
2238                                 type      = skip_typeref(orig_type);
2239
2240                                 sub = initializer_from_expression(orig_type, expression);
2241                                 if (sub != NULL) {
2242                                         break;
2243                                 }
2244                                 if (!is_type_valid(type)) {
2245                                         goto end_error;
2246                                 }
2247                                 if (is_type_scalar(type)) {
2248                                         errorf(&expression->base.source_position,
2249                                                         "expression '%E' doesn't match expected type '%T'",
2250                                                         expression, orig_type);
2251                                         goto end_error;
2252                                 }
2253
2254                                 descend_into_subtype(path);
2255                         }
2256                 }
2257
2258                 /* update largest index of top array */
2259                 const type_path_entry_t *first      = &path->path[0];
2260                 type_t                  *first_type = first->type;
2261                 first_type                          = skip_typeref(first_type);
2262                 if (is_type_array(first_type)) {
2263                         size_t index = first->v.index;
2264                         if (index > path->max_index)
2265                                 path->max_index = index;
2266                 }
2267
2268                 /* append to initializers list */
2269                 ARR_APP1(initializer_t*, initializers, sub);
2270
2271 error_parse_next:
2272                 if (token.type == '}') {
2273                         break;
2274                 }
2275                 expect(',', end_error);
2276                 if (token.type == '}') {
2277                         break;
2278                 }
2279
2280                 if (type != NULL) {
2281                         /* advance to the next declaration if we are not at the end */
2282                         advance_current_object(path, top_path_level);
2283                         orig_type = path->top_type;
2284                         if (orig_type != NULL)
2285                                 type = skip_typeref(orig_type);
2286                         else
2287                                 type = NULL;
2288                 }
2289         }
2290
2291         size_t len  = ARR_LEN(initializers);
2292         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2293         initializer_t *result = allocate_ast_zero(size);
2294         result->kind          = INITIALIZER_LIST;
2295         result->list.len      = len;
2296         memcpy(&result->list.initializers, initializers,
2297                len * sizeof(initializers[0]));
2298
2299         DEL_ARR_F(initializers);
2300         ascend_to(path, top_path_level+1);
2301
2302         return result;
2303
2304 end_error:
2305         skip_initializers();
2306         DEL_ARR_F(initializers);
2307         ascend_to(path, top_path_level+1);
2308         return NULL;
2309 }
2310
2311 static expression_t *make_size_literal(size_t value)
2312 {
2313         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2314         literal->base.type    = type_size_t;
2315
2316         char buf[128];
2317         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2318         literal->literal.value = make_string(buf);
2319
2320         return literal;
2321 }
2322
2323 /**
2324  * Parses an initializer. Parsers either a compound literal
2325  * (env->declaration == NULL) or an initializer of a declaration.
2326  */
2327 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2328 {
2329         type_t        *type      = skip_typeref(env->type);
2330         size_t         max_index = 0;
2331         initializer_t *result;
2332
2333         if (is_type_scalar(type)) {
2334                 result = parse_scalar_initializer(type, env->must_be_constant);
2335         } else if (token.type == '{') {
2336                 eat('{');
2337
2338                 type_path_t path;
2339                 memset(&path, 0, sizeof(path));
2340                 path.top_type = env->type;
2341                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2342
2343                 descend_into_subtype(&path);
2344
2345                 add_anchor_token('}');
2346                 result = parse_sub_initializer(&path, env->type, 1, env);
2347                 rem_anchor_token('}');
2348
2349                 max_index = path.max_index;
2350                 DEL_ARR_F(path.path);
2351
2352                 expect('}', end_error);
2353 end_error:;
2354         } else {
2355                 /* parse_scalar_initializer() also works in this case: we simply
2356                  * have an expression without {} around it */
2357                 result = parse_scalar_initializer(type, env->must_be_constant);
2358         }
2359
2360         /* §6.7.8:22 array initializers for arrays with unknown size determine
2361          * the array type size */
2362         if (is_type_array(type) && type->array.size_expression == NULL
2363                         && result != NULL) {
2364                 size_t size;
2365                 switch (result->kind) {
2366                 case INITIALIZER_LIST:
2367                         assert(max_index != 0xdeadbeaf);
2368                         size = max_index + 1;
2369                         break;
2370
2371                 case INITIALIZER_STRING:
2372                         size = result->string.string.size;
2373                         break;
2374
2375                 case INITIALIZER_WIDE_STRING:
2376                         size = result->wide_string.string.size;
2377                         break;
2378
2379                 case INITIALIZER_DESIGNATOR:
2380                 case INITIALIZER_VALUE:
2381                         /* can happen for parse errors */
2382                         size = 0;
2383                         break;
2384
2385                 default:
2386                         internal_errorf(HERE, "invalid initializer type");
2387                 }
2388
2389                 type_t *new_type = duplicate_type(type);
2390
2391                 new_type->array.size_expression   = make_size_literal(size);
2392                 new_type->array.size_constant     = true;
2393                 new_type->array.has_implicit_size = true;
2394                 new_type->array.size              = size;
2395                 env->type = new_type;
2396         }
2397
2398         return result;
2399 }
2400
2401 static void append_entity(scope_t *scope, entity_t *entity)
2402 {
2403         if (scope->last_entity != NULL) {
2404                 scope->last_entity->base.next = entity;
2405         } else {
2406                 scope->entities = entity;
2407         }
2408         entity->base.parent_entity = current_entity;
2409         scope->last_entity         = entity;
2410 }
2411
2412
2413 static compound_t *parse_compound_type_specifier(bool is_struct)
2414 {
2415         source_position_t const pos = *HERE;
2416         eat(is_struct ? T_struct : T_union);
2417
2418         symbol_t    *symbol     = NULL;
2419         entity_t    *entity     = NULL;
2420         attribute_t *attributes = NULL;
2421
2422         if (token.type == T___attribute__) {
2423                 attributes = parse_attributes(NULL);
2424         }
2425
2426         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2427         if (token.type == T_IDENTIFIER) {
2428                 /* the compound has a name, check if we have seen it already */
2429                 symbol = token.symbol;
2430                 entity = get_tag(symbol, kind);
2431                 next_token();
2432
2433                 if (entity != NULL) {
2434                         if (entity->base.parent_scope != current_scope &&
2435                             (token.type == '{' || token.type == ';')) {
2436                                 /* we're in an inner scope and have a definition. Shadow
2437                                  * existing definition in outer scope */
2438                                 entity = NULL;
2439                         } else if (entity->compound.complete && token.type == '{') {
2440                                 errorf(&pos, "multiple definitions of '%s %Y' (previous definition %P)",
2441                                        is_struct ? "struct" : "union", symbol,
2442                                        &entity->base.source_position);
2443                                 /* clear members in the hope to avoid further errors */
2444                                 entity->compound.members.entities = NULL;
2445                         }
2446                 }
2447         } else if (token.type != '{') {
2448                 char const *const msg =
2449                         is_struct ? "while parsing struct type specifier" :
2450                                     "while parsing union type specifier";
2451                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2452
2453                 return NULL;
2454         }
2455
2456         if (entity == NULL) {
2457                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol);
2458                 entity->compound.alignment   = 1;
2459                 entity->base.source_position = pos;
2460                 entity->base.parent_scope    = current_scope;
2461                 if (symbol != NULL) {
2462                         environment_push(entity);
2463                 }
2464                 append_entity(current_scope, entity);
2465         }
2466
2467         if (token.type == '{') {
2468                 parse_compound_type_entries(&entity->compound);
2469
2470                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2471                 if (symbol == NULL) {
2472                         assert(anonymous_entity == NULL);
2473                         anonymous_entity = entity;
2474                 }
2475         }
2476
2477         if (attributes != NULL) {
2478                 handle_entity_attributes(attributes, entity);
2479         }
2480
2481         return &entity->compound;
2482 }
2483
2484 static void parse_enum_entries(type_t *const enum_type)
2485 {
2486         eat('{');
2487
2488         if (token.type == '}') {
2489                 errorf(HERE, "empty enum not allowed");
2490                 next_token();
2491                 return;
2492         }
2493
2494         add_anchor_token('}');
2495         do {
2496                 if (token.type != T_IDENTIFIER) {
2497                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2498                         eat_block();
2499                         rem_anchor_token('}');
2500                         return;
2501                 }
2502
2503                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, token.symbol);
2504                 entity->enum_value.enum_type = enum_type;
2505                 entity->base.source_position = token.source_position;
2506                 next_token();
2507
2508                 if (next_if('=')) {
2509                         expression_t *value = parse_constant_expression();
2510
2511                         value = create_implicit_cast(value, enum_type);
2512                         entity->enum_value.value = value;
2513
2514                         /* TODO semantic */
2515                 }
2516
2517                 record_entity(entity, false);
2518         } while (next_if(',') && token.type != '}');
2519         rem_anchor_token('}');
2520
2521         expect('}', end_error);
2522
2523 end_error:
2524         ;
2525 }
2526
2527 static type_t *parse_enum_specifier(void)
2528 {
2529         source_position_t const pos = *HERE;
2530         entity_t               *entity;
2531         symbol_t               *symbol;
2532
2533         eat(T_enum);
2534         switch (token.type) {
2535                 case T_IDENTIFIER:
2536                         symbol = token.symbol;
2537                         entity = get_tag(symbol, ENTITY_ENUM);
2538                         next_token();
2539
2540                         if (entity != NULL) {
2541                                 if (entity->base.parent_scope != current_scope &&
2542                                                 (token.type == '{' || token.type == ';')) {
2543                                         /* we're in an inner scope and have a definition. Shadow
2544                                          * existing definition in outer scope */
2545                                         entity = NULL;
2546                                 } else if (entity->enume.complete && token.type == '{') {
2547                                         errorf(&pos, "multiple definitions of 'enum %Y' (previous definition %P)",
2548                                                         symbol, &entity->base.source_position);
2549                                 }
2550                         }
2551                         break;
2552
2553                 case '{':
2554                         entity = NULL;
2555                         symbol = NULL;
2556                         break;
2557
2558                 default:
2559                         parse_error_expected("while parsing enum type specifier",
2560                                         T_IDENTIFIER, '{', NULL);
2561                         return NULL;
2562         }
2563
2564         if (entity == NULL) {
2565                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol);
2566                 entity->base.source_position = pos;
2567                 entity->base.parent_scope    = current_scope;
2568         }
2569
2570         type_t *const type = allocate_type_zero(TYPE_ENUM);
2571         type->enumt.enume  = &entity->enume;
2572         type->enumt.akind  = ATOMIC_TYPE_INT;
2573
2574         if (token.type == '{') {
2575                 if (symbol != NULL) {
2576                         environment_push(entity);
2577                 }
2578                 append_entity(current_scope, entity);
2579                 entity->enume.complete = true;
2580
2581                 parse_enum_entries(type);
2582                 parse_attributes(NULL);
2583
2584                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2585                 if (symbol == NULL) {
2586                         assert(anonymous_entity == NULL);
2587                         anonymous_entity = entity;
2588                 }
2589         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2590                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2591         }
2592
2593         return type;
2594 }
2595
2596 /**
2597  * if a symbol is a typedef to another type, return true
2598  */
2599 static bool is_typedef_symbol(symbol_t *symbol)
2600 {
2601         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2602         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2603 }
2604
2605 static type_t *parse_typeof(void)
2606 {
2607         eat(T___typeof__);
2608
2609         type_t *type;
2610
2611         expect('(', end_error);
2612         add_anchor_token(')');
2613
2614         expression_t *expression  = NULL;
2615
2616         bool old_type_prop     = in_type_prop;
2617         bool old_gcc_extension = in_gcc_extension;
2618         in_type_prop           = true;
2619
2620         while (next_if(T___extension__)) {
2621                 /* This can be a prefix to a typename or an expression. */
2622                 in_gcc_extension = true;
2623         }
2624         switch (token.type) {
2625         case T_IDENTIFIER:
2626                 if (is_typedef_symbol(token.symbol)) {
2627         TYPENAME_START
2628                         type = parse_typename();
2629                 } else {
2630         default:
2631                         expression = parse_expression();
2632                         type       = revert_automatic_type_conversion(expression);
2633                 }
2634                 break;
2635         }
2636         in_type_prop     = old_type_prop;
2637         in_gcc_extension = old_gcc_extension;
2638
2639         rem_anchor_token(')');
2640         expect(')', end_error);
2641
2642         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2643         typeof_type->typeoft.expression  = expression;
2644         typeof_type->typeoft.typeof_type = type;
2645
2646         return typeof_type;
2647 end_error:
2648         return NULL;
2649 }
2650
2651 typedef enum specifiers_t {
2652         SPECIFIER_SIGNED    = 1 << 0,
2653         SPECIFIER_UNSIGNED  = 1 << 1,
2654         SPECIFIER_LONG      = 1 << 2,
2655         SPECIFIER_INT       = 1 << 3,
2656         SPECIFIER_DOUBLE    = 1 << 4,
2657         SPECIFIER_CHAR      = 1 << 5,
2658         SPECIFIER_WCHAR_T   = 1 << 6,
2659         SPECIFIER_SHORT     = 1 << 7,
2660         SPECIFIER_LONG_LONG = 1 << 8,
2661         SPECIFIER_FLOAT     = 1 << 9,
2662         SPECIFIER_BOOL      = 1 << 10,
2663         SPECIFIER_VOID      = 1 << 11,
2664         SPECIFIER_INT8      = 1 << 12,
2665         SPECIFIER_INT16     = 1 << 13,
2666         SPECIFIER_INT32     = 1 << 14,
2667         SPECIFIER_INT64     = 1 << 15,
2668         SPECIFIER_INT128    = 1 << 16,
2669         SPECIFIER_COMPLEX   = 1 << 17,
2670         SPECIFIER_IMAGINARY = 1 << 18,
2671 } specifiers_t;
2672
2673 static type_t *get_typedef_type(symbol_t *symbol)
2674 {
2675         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2676         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2677                 return NULL;
2678
2679         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2680         type->typedeft.typedefe = &entity->typedefe;
2681
2682         return type;
2683 }
2684
2685 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2686 {
2687         expect('(', end_error);
2688
2689         attribute_property_argument_t *property
2690                 = allocate_ast_zero(sizeof(*property));
2691
2692         do {
2693                 if (token.type != T_IDENTIFIER) {
2694                         parse_error_expected("while parsing property declspec",
2695                                              T_IDENTIFIER, NULL);
2696                         goto end_error;
2697                 }
2698
2699                 symbol_t **prop;
2700                 symbol_t  *symbol = token.symbol;
2701                 next_token();
2702                 if (strcmp(symbol->string, "put") == 0) {
2703                         prop = &property->put_symbol;
2704                 } else if (strcmp(symbol->string, "get") == 0) {
2705                         prop = &property->get_symbol;
2706                 } else {
2707                         errorf(HERE, "expected put or get in property declspec");
2708                         prop = NULL;
2709                 }
2710                 expect('=', end_error);
2711                 if (token.type != T_IDENTIFIER) {
2712                         parse_error_expected("while parsing property declspec",
2713                                              T_IDENTIFIER, NULL);
2714                         goto end_error;
2715                 }
2716                 if (prop != NULL)
2717                         *prop = token.symbol;
2718                 next_token();
2719         } while (next_if(','));
2720
2721         attribute->a.property = property;
2722
2723         expect(')', end_error);
2724
2725 end_error:
2726         return attribute;
2727 }
2728
2729 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2730 {
2731         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2732         if (next_if(T_restrict)) {
2733                 kind = ATTRIBUTE_MS_RESTRICT;
2734         } else if (token.type == T_IDENTIFIER) {
2735                 const char *name = token.symbol->string;
2736                 next_token();
2737                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2738                      ++k) {
2739                         const char *attribute_name = get_attribute_name(k);
2740                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2741                                 kind = k;
2742                                 break;
2743                         }
2744                 }
2745
2746                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2747                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2748                 }
2749         } else {
2750                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2751                 return NULL;
2752         }
2753
2754         attribute_t *attribute = allocate_attribute_zero(kind);
2755
2756         if (kind == ATTRIBUTE_MS_PROPERTY) {
2757                 return parse_attribute_ms_property(attribute);
2758         }
2759
2760         /* parse arguments */
2761         if (next_if('('))
2762                 attribute->a.arguments = parse_attribute_arguments();
2763
2764         return attribute;
2765 }
2766
2767 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2768 {
2769         eat(T__declspec);
2770
2771         expect('(', end_error);
2772
2773         if (next_if(')'))
2774                 return NULL;
2775
2776         add_anchor_token(')');
2777
2778         attribute_t **anchor = &first;
2779         do {
2780                 while (*anchor != NULL)
2781                         anchor = &(*anchor)->next;
2782
2783                 attribute_t *attribute
2784                         = parse_microsoft_extended_decl_modifier_single();
2785                 if (attribute == NULL)
2786                         goto end_error;
2787
2788                 *anchor = attribute;
2789                 anchor  = &attribute->next;
2790         } while (next_if(','));
2791
2792         rem_anchor_token(')');
2793         expect(')', end_error);
2794         return first;
2795
2796 end_error:
2797         rem_anchor_token(')');
2798         return first;
2799 }
2800
2801 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2802 {
2803         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol);
2804         entity->base.source_position = *HERE;
2805         if (is_declaration(entity)) {
2806                 entity->declaration.type     = type_error_type;
2807                 entity->declaration.implicit = true;
2808         } else if (kind == ENTITY_TYPEDEF) {
2809                 entity->typedefe.type    = type_error_type;
2810                 entity->typedefe.builtin = true;
2811         }
2812         if (kind != ENTITY_COMPOUND_MEMBER)
2813                 record_entity(entity, false);
2814         return entity;
2815 }
2816
2817 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2818 {
2819         type_t            *type              = NULL;
2820         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2821         unsigned           type_specifiers   = 0;
2822         bool               newtype           = false;
2823         bool               saw_error         = false;
2824         bool               old_gcc_extension = in_gcc_extension;
2825
2826         memset(specifiers, 0, sizeof(*specifiers));
2827         specifiers->source_position = token.source_position;
2828
2829         while (true) {
2830                 specifiers->attributes = parse_attributes(specifiers->attributes);
2831
2832                 switch (token.type) {
2833                 /* storage class */
2834 #define MATCH_STORAGE_CLASS(token, class)                                  \
2835                 case token:                                                        \
2836                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2837                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2838                         }                                                              \
2839                         specifiers->storage_class = class;                             \
2840                         if (specifiers->thread_local)                                  \
2841                                 goto check_thread_storage_class;                           \
2842                         next_token();                                                  \
2843                         break;
2844
2845                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2846                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2847                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2848                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2849                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2850
2851                 case T__declspec:
2852                         specifiers->attributes
2853                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2854                         break;
2855
2856                 case T___thread:
2857                         if (specifiers->thread_local) {
2858                                 errorf(HERE, "duplicate '__thread'");
2859                         } else {
2860                                 specifiers->thread_local = true;
2861 check_thread_storage_class:
2862                                 switch (specifiers->storage_class) {
2863                                         case STORAGE_CLASS_EXTERN:
2864                                         case STORAGE_CLASS_NONE:
2865                                         case STORAGE_CLASS_STATIC:
2866                                                 break;
2867
2868                                                 char const* wrong;
2869                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2870                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2871                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2872 wrong_thread_storage_class:
2873                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2874                                                 break;
2875                                 }
2876                         }
2877                         next_token();
2878                         break;
2879
2880                 /* type qualifiers */
2881 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2882                 case token:                                                     \
2883                         qualifiers |= qualifier;                                    \
2884                         next_token();                                               \
2885                         break
2886
2887                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2888                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2889                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2890                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2891                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2892                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2893                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2894                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2895
2896                 case T___extension__:
2897                         next_token();
2898                         in_gcc_extension = true;
2899                         break;
2900
2901                 /* type specifiers */
2902 #define MATCH_SPECIFIER(token, specifier, name)                         \
2903                 case token:                                                     \
2904                         if (type_specifiers & specifier) {                           \
2905                                 errorf(HERE, "multiple " name " type specifiers given"); \
2906                         } else {                                                    \
2907                                 type_specifiers |= specifier;                           \
2908                         }                                                           \
2909                         next_token();                                               \
2910                         break
2911
2912                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2913                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2914                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2915                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2916                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2917                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2918                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2919                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2920                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2921                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2922                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2923                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2924                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2925                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2926                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2927                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2928                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2929                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2930
2931                 case T_inline:
2932                         next_token();
2933                         specifiers->is_inline = true;
2934                         break;
2935
2936 #if 0
2937                 case T__forceinline:
2938                         next_token();
2939                         specifiers->modifiers |= DM_FORCEINLINE;
2940                         break;
2941 #endif
2942
2943                 case T_long:
2944                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2945                                 errorf(HERE, "too many long type specifiers given");
2946                         } else if (type_specifiers & SPECIFIER_LONG) {
2947                                 type_specifiers |= SPECIFIER_LONG_LONG;
2948                         } else {
2949                                 type_specifiers |= SPECIFIER_LONG;
2950                         }
2951                         next_token();
2952                         break;
2953
2954 #define CHECK_DOUBLE_TYPE()        \
2955                         if ( type != NULL)     \
2956                                 errorf(HERE, "multiple data types in declaration specifiers");
2957
2958                 case T_struct:
2959                         CHECK_DOUBLE_TYPE();
2960                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2961
2962                         type->compound.compound = parse_compound_type_specifier(true);
2963                         break;
2964                 case T_union:
2965                         CHECK_DOUBLE_TYPE();
2966                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2967                         type->compound.compound = parse_compound_type_specifier(false);
2968                         break;
2969                 case T_enum:
2970                         CHECK_DOUBLE_TYPE();
2971                         type = parse_enum_specifier();
2972                         break;
2973                 case T___typeof__:
2974                         CHECK_DOUBLE_TYPE();
2975                         type = parse_typeof();
2976                         break;
2977                 case T___builtin_va_list:
2978                         CHECK_DOUBLE_TYPE();
2979                         type = duplicate_type(type_valist);
2980                         next_token();
2981                         break;
2982
2983                 case T_IDENTIFIER: {
2984                         /* only parse identifier if we haven't found a type yet */
2985                         if (type != NULL || type_specifiers != 0) {
2986                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2987                                  * declaration, so it doesn't generate errors about expecting '(' or
2988                                  * '{' later on. */
2989                                 switch (look_ahead(1)->type) {
2990                                         STORAGE_CLASSES
2991                                         TYPE_SPECIFIERS
2992                                         case T_const:
2993                                         case T_restrict:
2994                                         case T_volatile:
2995                                         case T_inline:
2996                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2997                                         case T_IDENTIFIER:
2998                                         case '&':
2999                                         case '*':
3000                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3001                                                 next_token();
3002                                                 continue;
3003
3004                                         default:
3005                                                 goto finish_specifiers;
3006                                 }
3007                         }
3008
3009                         type_t *const typedef_type = get_typedef_type(token.symbol);
3010                         if (typedef_type == NULL) {
3011                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3012                                  * declaration, so it doesn't generate 'implicit int' followed by more
3013                                  * errors later on. */
3014                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3015                                 switch (la1_type) {
3016                                         DECLARATION_START
3017                                         case T_IDENTIFIER:
3018                                         case '&':
3019                                         case '*': {
3020                                                 errorf(HERE, "%K does not name a type", &token);
3021
3022                                                 entity_t *entity =
3023                                                         create_error_entity(token.symbol, ENTITY_TYPEDEF);
3024
3025                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3026                                                 type->typedeft.typedefe = &entity->typedefe;
3027
3028                                                 next_token();
3029                                                 saw_error = true;
3030                                                 continue;
3031                                         }
3032
3033                                         default:
3034                                                 goto finish_specifiers;
3035                                 }
3036                         }
3037
3038                         next_token();
3039                         type = typedef_type;
3040                         break;
3041                 }
3042
3043                 /* function specifier */
3044                 default:
3045                         goto finish_specifiers;
3046                 }
3047         }
3048
3049 finish_specifiers:
3050         specifiers->attributes = parse_attributes(specifiers->attributes);
3051
3052         in_gcc_extension = old_gcc_extension;
3053
3054         if (type == NULL || (saw_error && type_specifiers != 0)) {
3055                 atomic_type_kind_t atomic_type;
3056
3057                 /* match valid basic types */
3058                 switch (type_specifiers) {
3059                 case SPECIFIER_VOID:
3060                         atomic_type = ATOMIC_TYPE_VOID;
3061                         break;
3062                 case SPECIFIER_WCHAR_T:
3063                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3064                         break;
3065                 case SPECIFIER_CHAR:
3066                         atomic_type = ATOMIC_TYPE_CHAR;
3067                         break;
3068                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3069                         atomic_type = ATOMIC_TYPE_SCHAR;
3070                         break;
3071                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3072                         atomic_type = ATOMIC_TYPE_UCHAR;
3073                         break;
3074                 case SPECIFIER_SHORT:
3075                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3076                 case SPECIFIER_SHORT | SPECIFIER_INT:
3077                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3078                         atomic_type = ATOMIC_TYPE_SHORT;
3079                         break;
3080                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3081                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3082                         atomic_type = ATOMIC_TYPE_USHORT;
3083                         break;
3084                 case SPECIFIER_INT:
3085                 case SPECIFIER_SIGNED:
3086                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3087                         atomic_type = ATOMIC_TYPE_INT;
3088                         break;
3089                 case SPECIFIER_UNSIGNED:
3090                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3091                         atomic_type = ATOMIC_TYPE_UINT;
3092                         break;
3093                 case SPECIFIER_LONG:
3094                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3095                 case SPECIFIER_LONG | SPECIFIER_INT:
3096                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3097                         atomic_type = ATOMIC_TYPE_LONG;
3098                         break;
3099                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3100                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3101                         atomic_type = ATOMIC_TYPE_ULONG;
3102                         break;
3103
3104                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3105                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3106                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3107                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3108                         | SPECIFIER_INT:
3109                         atomic_type = ATOMIC_TYPE_LONGLONG;
3110                         goto warn_about_long_long;
3111
3112                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3113                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3114                         | SPECIFIER_INT:
3115                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3116 warn_about_long_long:
3117                         if (warning.long_long) {
3118                                 warningf(&specifiers->source_position,
3119                                          "ISO C90 does not support 'long long'");
3120                         }
3121                         break;
3122
3123                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3124                         atomic_type = unsigned_int8_type_kind;
3125                         break;
3126
3127                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3128                         atomic_type = unsigned_int16_type_kind;
3129                         break;
3130
3131                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3132                         atomic_type = unsigned_int32_type_kind;
3133                         break;
3134
3135                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3136                         atomic_type = unsigned_int64_type_kind;
3137                         break;
3138
3139                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3140                         atomic_type = unsigned_int128_type_kind;
3141                         break;
3142
3143                 case SPECIFIER_INT8:
3144                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3145                         atomic_type = int8_type_kind;
3146                         break;
3147
3148                 case SPECIFIER_INT16:
3149                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3150                         atomic_type = int16_type_kind;
3151                         break;
3152
3153                 case SPECIFIER_INT32:
3154                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3155                         atomic_type = int32_type_kind;
3156                         break;
3157
3158                 case SPECIFIER_INT64:
3159                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3160                         atomic_type = int64_type_kind;
3161                         break;
3162
3163                 case SPECIFIER_INT128:
3164                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3165                         atomic_type = int128_type_kind;
3166                         break;
3167
3168                 case SPECIFIER_FLOAT:
3169                         atomic_type = ATOMIC_TYPE_FLOAT;
3170                         break;
3171                 case SPECIFIER_DOUBLE:
3172                         atomic_type = ATOMIC_TYPE_DOUBLE;
3173                         break;
3174                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3175                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3176                         break;
3177                 case SPECIFIER_BOOL:
3178                         atomic_type = ATOMIC_TYPE_BOOL;
3179                         break;
3180                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3181                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3182                         atomic_type = ATOMIC_TYPE_FLOAT;
3183                         break;
3184                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3185                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3186                         atomic_type = ATOMIC_TYPE_DOUBLE;
3187                         break;
3188                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3189                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3190                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3191                         break;
3192                 default:
3193                         /* invalid specifier combination, give an error message */
3194                         if (type_specifiers == 0) {
3195                                 if (!saw_error) {
3196                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3197                                         if (!(c_mode & _CXX) && !strict_mode) {
3198                                                 if (warning.implicit_int) {
3199                                                         warningf(HERE, "no type specifiers in declaration, using 'int'");
3200                                                 }
3201                                                 atomic_type = ATOMIC_TYPE_INT;
3202                                                 break;
3203                                         } else {
3204                                                 errorf(HERE, "no type specifiers given in declaration");
3205                                         }
3206                                 }
3207                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3208                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3209                                 errorf(HERE, "signed and unsigned specifiers given");
3210                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3211                                 errorf(HERE, "only integer types can be signed or unsigned");
3212                         } else {
3213                                 errorf(HERE, "multiple datatypes in declaration");
3214                         }
3215                         goto end_error;
3216                 }
3217
3218                 if (type_specifiers & SPECIFIER_COMPLEX) {
3219                         type                = allocate_type_zero(TYPE_COMPLEX);
3220                         type->complex.akind = atomic_type;
3221                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3222                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3223                         type->imaginary.akind = atomic_type;
3224                 } else {
3225                         type                 = allocate_type_zero(TYPE_ATOMIC);
3226                         type->atomic.akind   = atomic_type;
3227                 }
3228                 newtype = true;
3229         } else if (type_specifiers != 0) {
3230                 errorf(HERE, "multiple datatypes in declaration");
3231         }
3232
3233         /* FIXME: check type qualifiers here */
3234         type->base.qualifiers = qualifiers;
3235
3236         if (newtype) {
3237                 type = identify_new_type(type);
3238         } else {
3239                 type = typehash_insert(type);
3240         }
3241
3242         if (specifiers->attributes != NULL)
3243                 type = handle_type_attributes(specifiers->attributes, type);
3244         specifiers->type = type;
3245         return;
3246
3247 end_error:
3248         specifiers->type = type_error_type;
3249 }
3250
3251 static type_qualifiers_t parse_type_qualifiers(void)
3252 {
3253         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3254
3255         while (true) {
3256                 switch (token.type) {
3257                 /* type qualifiers */
3258                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3259                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3260                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3261                 /* microsoft extended type modifiers */
3262                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3263                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3264                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3265                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3266                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3267
3268                 default:
3269                         return qualifiers;
3270                 }
3271         }
3272 }
3273
3274 /**
3275  * Parses an K&R identifier list
3276  */
3277 static void parse_identifier_list(scope_t *scope)
3278 {
3279         do {
3280                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.symbol);
3281                 entity->base.source_position = token.source_position;
3282                 /* a K&R parameter has no type, yet */
3283                 next_token();
3284
3285                 if (scope != NULL)
3286                         append_entity(scope, entity);
3287         } while (next_if(',') && token.type == T_IDENTIFIER);
3288 }
3289
3290 static entity_t *parse_parameter(void)
3291 {
3292         declaration_specifiers_t specifiers;
3293         parse_declaration_specifiers(&specifiers);
3294
3295         entity_t *entity = parse_declarator(&specifiers,
3296                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3297         anonymous_entity = NULL;
3298         return entity;
3299 }
3300
3301 static void semantic_parameter_incomplete(const entity_t *entity)
3302 {
3303         assert(entity->kind == ENTITY_PARAMETER);
3304
3305         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3306          *             list in a function declarator that is part of a
3307          *             definition of that function shall not have
3308          *             incomplete type. */
3309         type_t *type = skip_typeref(entity->declaration.type);
3310         if (is_type_incomplete(type)) {
3311                 errorf(&entity->base.source_position,
3312                                 "parameter '%#T' has incomplete type",
3313                                 entity->declaration.type, entity->base.symbol);
3314         }
3315 }
3316
3317 static bool has_parameters(void)
3318 {
3319         /* func(void) is not a parameter */
3320         if (token.type == T_IDENTIFIER) {
3321                 entity_t const *const entity = get_entity(token.symbol, NAMESPACE_NORMAL);
3322                 if (entity == NULL)
3323                         return true;
3324                 if (entity->kind != ENTITY_TYPEDEF)
3325                         return true;
3326                 if (skip_typeref(entity->typedefe.type) != type_void)
3327                         return true;
3328         } else if (token.type != T_void) {
3329                 return true;
3330         }
3331         if (look_ahead(1)->type != ')')
3332                 return true;
3333         next_token();
3334         return false;
3335 }
3336
3337 /**
3338  * Parses function type parameters (and optionally creates variable_t entities
3339  * for them in a scope)
3340  */
3341 static void parse_parameters(function_type_t *type, scope_t *scope)
3342 {
3343         eat('(');
3344         add_anchor_token(')');
3345         int saved_comma_state = save_and_reset_anchor_state(',');
3346
3347         if (token.type == T_IDENTIFIER &&
3348             !is_typedef_symbol(token.symbol)) {
3349                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3350                 if (la1_type == ',' || la1_type == ')') {
3351                         type->kr_style_parameters = true;
3352                         parse_identifier_list(scope);
3353                         goto parameters_finished;
3354                 }
3355         }
3356
3357         if (token.type == ')') {
3358                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3359                 if (!(c_mode & _CXX))
3360                         type->unspecified_parameters = true;
3361         } else if (has_parameters()) {
3362                 function_parameter_t **anchor = &type->parameters;
3363                 do {
3364                         switch (token.type) {
3365                         case T_DOTDOTDOT:
3366                                 next_token();
3367                                 type->variadic = true;
3368                                 goto parameters_finished;
3369
3370                         case T_IDENTIFIER:
3371                         case T___extension__:
3372                         DECLARATION_START
3373                         {
3374                                 entity_t *entity = parse_parameter();
3375                                 if (entity->kind == ENTITY_TYPEDEF) {
3376                                         errorf(&entity->base.source_position,
3377                                                         "typedef not allowed as function parameter");
3378                                         break;
3379                                 }
3380                                 assert(is_declaration(entity));
3381
3382                                 semantic_parameter_incomplete(entity);
3383
3384                                 function_parameter_t *const parameter =
3385                                         allocate_parameter(entity->declaration.type);
3386
3387                                 if (scope != NULL) {
3388                                         append_entity(scope, entity);
3389                                 }
3390
3391                                 *anchor = parameter;
3392                                 anchor  = &parameter->next;
3393                                 break;
3394                         }
3395
3396                         default:
3397                                 goto parameters_finished;
3398                         }
3399                 } while (next_if(','));
3400         }
3401
3402 parameters_finished:
3403         rem_anchor_token(')');
3404         expect(')', end_error);
3405
3406 end_error:
3407         restore_anchor_state(',', saved_comma_state);
3408 }
3409
3410 typedef enum construct_type_kind_t {
3411         CONSTRUCT_INVALID,
3412         CONSTRUCT_POINTER,
3413         CONSTRUCT_REFERENCE,
3414         CONSTRUCT_FUNCTION,
3415         CONSTRUCT_ARRAY
3416 } construct_type_kind_t;
3417
3418 typedef union construct_type_t construct_type_t;
3419
3420 typedef struct construct_type_base_t {
3421         construct_type_kind_t  kind;
3422         source_position_t      pos;
3423         construct_type_t      *next;
3424 } construct_type_base_t;
3425
3426 typedef struct parsed_pointer_t {
3427         construct_type_base_t  base;
3428         type_qualifiers_t      type_qualifiers;
3429         variable_t            *base_variable;  /**< MS __based extension. */
3430 } parsed_pointer_t;
3431
3432 typedef struct parsed_reference_t {
3433         construct_type_base_t base;
3434 } parsed_reference_t;
3435
3436 typedef struct construct_function_type_t {
3437         construct_type_base_t  base;
3438         type_t                *function_type;
3439 } construct_function_type_t;
3440
3441 typedef struct parsed_array_t {
3442         construct_type_base_t  base;
3443         type_qualifiers_t      type_qualifiers;
3444         bool                   is_static;
3445         bool                   is_variable;
3446         expression_t          *size;
3447 } parsed_array_t;
3448
3449 union construct_type_t {
3450         construct_type_kind_t     kind;
3451         construct_type_base_t     base;
3452         parsed_pointer_t          pointer;
3453         parsed_reference_t        reference;
3454         construct_function_type_t function;
3455         parsed_array_t            array;
3456 };
3457
3458 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3459 {
3460         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3461         memset(cons, 0, size);
3462         cons->kind     = kind;
3463         cons->base.pos = *HERE;
3464         return cons;
3465 }
3466
3467 /* §6.7.5.1 */
3468 static construct_type_t *parse_pointer_declarator(void)
3469 {
3470         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3471         eat('*');
3472         cons->pointer.type_qualifiers = parse_type_qualifiers();
3473         //cons->pointer.base_variable   = base_variable;
3474
3475         return cons;
3476 }
3477
3478 /* ISO/IEC 14882:1998(E) §8.3.2 */
3479 static construct_type_t *parse_reference_declarator(void)
3480 {
3481         if (!(c_mode & _CXX))
3482                 errorf(HERE, "references are only available for C++");
3483
3484         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3485         eat('&');
3486
3487         return cons;
3488 }
3489
3490 /* §6.7.5.2 */
3491 static construct_type_t *parse_array_declarator(void)
3492 {
3493         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3494         parsed_array_t   *const array = &cons->array;
3495
3496         eat('[');
3497         add_anchor_token(']');
3498
3499         bool is_static = next_if(T_static);
3500
3501         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3502
3503         if (!is_static)
3504                 is_static = next_if(T_static);
3505
3506         array->type_qualifiers = type_qualifiers;
3507         array->is_static       = is_static;
3508
3509         expression_t *size = NULL;
3510         if (token.type == '*' && look_ahead(1)->type == ']') {
3511                 array->is_variable = true;
3512                 next_token();
3513         } else if (token.type != ']') {
3514                 size = parse_assignment_expression();
3515
3516                 /* §6.7.5.2:1  Array size must have integer type */
3517                 type_t *const orig_type = size->base.type;
3518                 type_t *const type      = skip_typeref(orig_type);
3519                 if (!is_type_integer(type) && is_type_valid(type)) {
3520                         errorf(&size->base.source_position,
3521                                "array size '%E' must have integer type but has type '%T'",
3522                                size, orig_type);
3523                 }
3524
3525                 array->size = size;
3526                 mark_vars_read(size, NULL);
3527         }
3528
3529         if (is_static && size == NULL)
3530                 errorf(&array->base.pos, "static array parameters require a size");
3531
3532         rem_anchor_token(']');
3533         expect(']', end_error);
3534
3535 end_error:
3536         return cons;
3537 }
3538
3539 /* §6.7.5.3 */
3540 static construct_type_t *parse_function_declarator(scope_t *scope)
3541 {
3542         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3543
3544         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3545         function_type_t *ftype = &type->function;
3546
3547         ftype->linkage            = current_linkage;
3548         ftype->calling_convention = CC_DEFAULT;
3549
3550         parse_parameters(ftype, scope);
3551
3552         cons->function.function_type = type;
3553
3554         return cons;
3555 }
3556
3557 typedef struct parse_declarator_env_t {
3558         bool               may_be_abstract : 1;
3559         bool               must_be_abstract : 1;
3560         decl_modifiers_t   modifiers;
3561         symbol_t          *symbol;
3562         source_position_t  source_position;
3563         scope_t            parameters;
3564         attribute_t       *attributes;
3565 } parse_declarator_env_t;
3566
3567 /* §6.7.5 */
3568 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3569 {
3570         /* construct a single linked list of construct_type_t's which describe
3571          * how to construct the final declarator type */
3572         construct_type_t  *first      = NULL;
3573         construct_type_t **anchor     = &first;
3574
3575         env->attributes = parse_attributes(env->attributes);
3576
3577         for (;;) {
3578                 construct_type_t *type;
3579                 //variable_t       *based = NULL; /* MS __based extension */
3580                 switch (token.type) {
3581                         case '&':
3582                                 type = parse_reference_declarator();
3583                                 break;
3584
3585                         case T__based: {
3586                                 panic("based not supported anymore");
3587                                 /* FALLTHROUGH */
3588                         }
3589
3590                         case '*':
3591                                 type = parse_pointer_declarator();
3592                                 break;
3593
3594                         default:
3595                                 goto ptr_operator_end;
3596                 }
3597
3598                 *anchor = type;
3599                 anchor  = &type->base.next;
3600
3601                 /* TODO: find out if this is correct */
3602                 env->attributes = parse_attributes(env->attributes);
3603         }
3604
3605 ptr_operator_end: ;
3606         construct_type_t *inner_types = NULL;
3607
3608         switch (token.type) {
3609         case T_IDENTIFIER:
3610                 if (env->must_be_abstract) {
3611                         errorf(HERE, "no identifier expected in typename");
3612                 } else {
3613                         env->symbol          = token.symbol;
3614                         env->source_position = token.source_position;
3615                 }
3616                 next_token();
3617                 break;
3618
3619         case '(': {
3620                 /* Parenthesized declarator or function declarator? */
3621                 token_t const *const la1 = look_ahead(1);
3622                 switch (la1->type) {
3623                         case T_IDENTIFIER:
3624                                 if (is_typedef_symbol(la1->symbol)) {
3625                         case ')':
3626                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3627                                          * interpreted as ``function with no parameter specification'', rather
3628                                          * than redundant parentheses around the omitted identifier. */
3629                         default:
3630                                         /* Function declarator. */
3631                                         if (!env->may_be_abstract) {
3632                                                 errorf(HERE, "function declarator must have a name");
3633                                         }
3634                                 } else {
3635                         case '&':
3636                         case '(':
3637                         case '*':
3638                         case '[':
3639                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3640                                         /* Paranthesized declarator. */
3641                                         next_token();
3642                                         add_anchor_token(')');
3643                                         inner_types = parse_inner_declarator(env);
3644                                         if (inner_types != NULL) {
3645                                                 /* All later declarators only modify the return type */
3646                                                 env->must_be_abstract = true;
3647                                         }
3648                                         rem_anchor_token(')');
3649                                         expect(')', end_error);
3650                                 }
3651                                 break;
3652                 }
3653                 break;
3654         }
3655
3656         default:
3657                 if (env->may_be_abstract)
3658                         break;
3659                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3660                 eat_until_anchor();
3661                 return NULL;
3662         }
3663
3664         construct_type_t **const p = anchor;
3665
3666         for (;;) {
3667                 construct_type_t *type;
3668                 switch (token.type) {
3669                 case '(': {
3670                         scope_t *scope = NULL;
3671                         if (!env->must_be_abstract) {
3672                                 scope = &env->parameters;
3673                         }
3674
3675                         type = parse_function_declarator(scope);
3676                         break;
3677                 }
3678                 case '[':
3679                         type = parse_array_declarator();
3680                         break;
3681                 default:
3682                         goto declarator_finished;
3683                 }
3684
3685                 /* insert in the middle of the list (at p) */
3686                 type->base.next = *p;
3687                 *p              = type;
3688                 if (anchor == p)
3689                         anchor = &type->base.next;
3690         }
3691
3692 declarator_finished:
3693         /* append inner_types at the end of the list, we don't to set anchor anymore
3694          * as it's not needed anymore */
3695         *anchor = inner_types;
3696
3697         return first;
3698 end_error:
3699         return NULL;
3700 }
3701
3702 static type_t *construct_declarator_type(construct_type_t *construct_list,
3703                                          type_t *type)
3704 {
3705         construct_type_t *iter = construct_list;
3706         for (; iter != NULL; iter = iter->base.next) {
3707                 source_position_t const* const pos = &iter->base.pos;
3708                 switch (iter->kind) {
3709                 case CONSTRUCT_INVALID:
3710                         break;
3711                 case CONSTRUCT_FUNCTION: {
3712                         construct_function_type_t *function      = &iter->function;
3713                         type_t                    *function_type = function->function_type;
3714
3715                         function_type->function.return_type = type;
3716
3717                         type_t *skipped_return_type = skip_typeref(type);
3718                         /* §6.7.5.3:1 */
3719                         if (is_type_function(skipped_return_type)) {
3720                                 errorf(pos, "function returning function is not allowed");
3721                         } else if (is_type_array(skipped_return_type)) {
3722                                 errorf(pos, "function returning array is not allowed");
3723                         } else {
3724                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3725                                         warningf(pos, "type qualifiers in return type of function type are meaningless");
3726                                 }
3727                         }
3728
3729                         /* The function type was constructed earlier.  Freeing it here will
3730                          * destroy other types. */
3731                         type = typehash_insert(function_type);
3732                         continue;
3733                 }
3734
3735                 case CONSTRUCT_POINTER: {
3736                         if (is_type_reference(skip_typeref(type)))
3737                                 errorf(pos, "cannot declare a pointer to reference");
3738
3739                         parsed_pointer_t *pointer = &iter->pointer;
3740                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3741                         continue;
3742                 }
3743
3744                 case CONSTRUCT_REFERENCE:
3745                         if (is_type_reference(skip_typeref(type)))
3746                                 errorf(pos, "cannot declare a reference to reference");
3747
3748                         type = make_reference_type(type);
3749                         continue;
3750
3751                 case CONSTRUCT_ARRAY: {
3752                         if (is_type_reference(skip_typeref(type)))
3753                                 errorf(pos, "cannot declare an array of references");
3754
3755                         parsed_array_t *array      = &iter->array;
3756                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3757
3758                         expression_t *size_expression = array->size;
3759                         if (size_expression != NULL) {
3760                                 size_expression
3761                                         = create_implicit_cast(size_expression, type_size_t);
3762                         }
3763
3764                         array_type->base.qualifiers       = array->type_qualifiers;
3765                         array_type->array.element_type    = type;
3766                         array_type->array.is_static       = array->is_static;
3767                         array_type->array.is_variable     = array->is_variable;
3768                         array_type->array.size_expression = size_expression;
3769
3770                         if (size_expression != NULL) {
3771                                 switch (is_constant_expression(size_expression)) {
3772                                         case EXPR_CLASS_CONSTANT: {
3773                                                 long const size = fold_constant_to_int(size_expression);
3774                                                 array_type->array.size          = size;
3775                                                 array_type->array.size_constant = true;
3776                                                 /* §6.7.5.2:1  If the expression is a constant expression, it shall
3777                                                  * have a value greater than zero. */
3778                                                 if (size <= 0) {
3779                                                         if (size < 0 || !GNU_MODE) {
3780                                                                 errorf(&size_expression->base.source_position,
3781                                                                                 "size of array must be greater than zero");
3782                                                         } else if (warning.other) {
3783                                                                 warningf(&size_expression->base.source_position,
3784                                                                                 "zero length arrays are a GCC extension");
3785                                                         }
3786                                                 }
3787                                                 break;
3788                                         }
3789
3790                                         case EXPR_CLASS_VARIABLE:
3791                                                 array_type->array.is_vla = true;
3792                                                 break;
3793
3794                                         case EXPR_CLASS_ERROR:
3795                                                 break;
3796                                 }
3797                         }
3798
3799                         type_t *skipped_type = skip_typeref(type);
3800                         /* §6.7.5.2:1 */
3801                         if (is_type_incomplete(skipped_type)) {
3802                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3803                         } else if (is_type_function(skipped_type)) {
3804                                 errorf(pos, "array of functions is not allowed");
3805                         }
3806                         type = identify_new_type(array_type);
3807                         continue;
3808                 }
3809                 }
3810                 internal_errorf(pos, "invalid type construction found");
3811         }
3812
3813         return type;
3814 }
3815
3816 static type_t *automatic_type_conversion(type_t *orig_type);
3817
3818 static type_t *semantic_parameter(const source_position_t *pos,
3819                                   type_t *type,
3820                                   const declaration_specifiers_t *specifiers,
3821                                   symbol_t *symbol)
3822 {
3823         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3824          *             shall be adjusted to ``qualified pointer to type'',
3825          *             [...]
3826          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3827          *             type'' shall be adjusted to ``pointer to function
3828          *             returning type'', as in 6.3.2.1. */
3829         type = automatic_type_conversion(type);
3830
3831         if (specifiers->is_inline && is_type_valid(type)) {
3832                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
3833         }
3834
3835         /* §6.9.1:6  The declarations in the declaration list shall contain
3836          *           no storage-class specifier other than register and no
3837          *           initializations. */
3838         if (specifiers->thread_local || (
3839                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3840                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3841            ) {
3842                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
3843         }
3844
3845         /* delay test for incomplete type, because we might have (void)
3846          * which is legal but incomplete... */
3847
3848         return type;
3849 }
3850
3851 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3852                                   declarator_flags_t flags)
3853 {
3854         parse_declarator_env_t env;
3855         memset(&env, 0, sizeof(env));
3856         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3857
3858         construct_type_t *construct_type = parse_inner_declarator(&env);
3859         type_t           *orig_type      =
3860                 construct_declarator_type(construct_type, specifiers->type);
3861         type_t           *type           = skip_typeref(orig_type);
3862
3863         if (construct_type != NULL) {
3864                 obstack_free(&temp_obst, construct_type);
3865         }
3866
3867         attribute_t *attributes = parse_attributes(env.attributes);
3868         /* append (shared) specifier attribute behind attributes of this
3869          * declarator */
3870         attribute_t **anchor = &attributes;
3871         while (*anchor != NULL)
3872                 anchor = &(*anchor)->next;
3873         *anchor = specifiers->attributes;
3874
3875         entity_t *entity;
3876         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3877                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol);
3878                 entity->base.source_position = env.source_position;
3879                 entity->typedefe.type        = orig_type;
3880
3881                 if (anonymous_entity != NULL) {
3882                         if (is_type_compound(type)) {
3883                                 assert(anonymous_entity->compound.alias == NULL);
3884                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3885                                        anonymous_entity->kind == ENTITY_UNION);
3886                                 anonymous_entity->compound.alias = entity;
3887                                 anonymous_entity = NULL;
3888                         } else if (is_type_enum(type)) {
3889                                 assert(anonymous_entity->enume.alias == NULL);
3890                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3891                                 anonymous_entity->enume.alias = entity;
3892                                 anonymous_entity = NULL;
3893                         }
3894                 }
3895         } else {
3896                 /* create a declaration type entity */
3897                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3898                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol);
3899
3900                         if (env.symbol != NULL) {
3901                                 if (specifiers->is_inline && is_type_valid(type)) {
3902                                         errorf(&env.source_position,
3903                                                         "compound member '%Y' declared 'inline'", env.symbol);
3904                                 }
3905
3906                                 if (specifiers->thread_local ||
3907                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3908                                         errorf(&env.source_position,
3909                                                         "compound member '%Y' must have no storage class",
3910                                                         env.symbol);
3911                                 }
3912                         }
3913                 } else if (flags & DECL_IS_PARAMETER) {
3914                         orig_type = semantic_parameter(&env.source_position, orig_type,
3915                                                        specifiers, env.symbol);
3916
3917                         entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol);
3918                 } else if (is_type_function(type)) {
3919                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol);
3920                         entity->function.is_inline      = specifiers->is_inline;
3921                         entity->function.elf_visibility = default_visibility;
3922                         entity->function.parameters     = env.parameters;
3923
3924                         if (env.symbol != NULL) {
3925                                 /* this needs fixes for C++ */
3926                                 bool in_function_scope = current_function != NULL;
3927
3928                                 if (specifiers->thread_local || (
3929                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3930                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3931                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3932                                                 )) {
3933                                         errorf(&env.source_position,
3934                                                         "invalid storage class for function '%Y'", env.symbol);
3935                                 }
3936                         }
3937                 } else {
3938                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol);
3939                         entity->variable.elf_visibility = default_visibility;
3940                         entity->variable.thread_local   = specifiers->thread_local;
3941
3942                         if (env.symbol != NULL) {
3943                                 if (specifiers->is_inline && is_type_valid(type)) {
3944                                         errorf(&env.source_position,
3945                                                         "variable '%Y' declared 'inline'", env.symbol);
3946                                 }
3947
3948                                 bool invalid_storage_class = false;
3949                                 if (current_scope == file_scope) {
3950                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3951                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3952                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3953                                                 invalid_storage_class = true;
3954                                         }
3955                                 } else {
3956                                         if (specifiers->thread_local &&
3957                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3958                                                 invalid_storage_class = true;
3959                                         }
3960                                 }
3961                                 if (invalid_storage_class) {
3962                                         errorf(&env.source_position,
3963                                                         "invalid storage class for variable '%Y'", env.symbol);
3964                                 }
3965                         }
3966                 }
3967
3968                 entity->base.source_position   = env.symbol != NULL ? env.source_position : specifiers->source_position;
3969                 entity->declaration.type       = orig_type;
3970                 entity->declaration.alignment  = get_type_alignment(orig_type);
3971                 entity->declaration.modifiers  = env.modifiers;
3972                 entity->declaration.attributes = attributes;
3973
3974                 storage_class_t storage_class = specifiers->storage_class;
3975                 entity->declaration.declared_storage_class = storage_class;
3976
3977                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3978                         storage_class = STORAGE_CLASS_AUTO;
3979                 entity->declaration.storage_class = storage_class;
3980         }
3981
3982         if (attributes != NULL) {
3983                 handle_entity_attributes(attributes, entity);
3984         }
3985
3986         return entity;
3987 }
3988
3989 static type_t *parse_abstract_declarator(type_t *base_type)
3990 {
3991         parse_declarator_env_t env;
3992         memset(&env, 0, sizeof(env));
3993         env.may_be_abstract = true;
3994         env.must_be_abstract = true;
3995
3996         construct_type_t *construct_type = parse_inner_declarator(&env);
3997
3998         type_t *result = construct_declarator_type(construct_type, base_type);
3999         if (construct_type != NULL) {
4000                 obstack_free(&temp_obst, construct_type);
4001         }
4002         result = handle_type_attributes(env.attributes, result);
4003
4004         return result;
4005 }
4006
4007 /**
4008  * Check if the declaration of main is suspicious.  main should be a
4009  * function with external linkage, returning int, taking either zero
4010  * arguments, two, or three arguments of appropriate types, ie.
4011  *
4012  * int main([ int argc, char **argv [, char **env ] ]).
4013  *
4014  * @param decl    the declaration to check
4015  * @param type    the function type of the declaration
4016  */
4017 static void check_main(const entity_t *entity)
4018 {
4019         const source_position_t *pos = &entity->base.source_position;
4020         if (entity->kind != ENTITY_FUNCTION) {
4021                 warningf(pos, "'main' is not a function");
4022                 return;
4023         }
4024
4025         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4026                 warningf(pos, "'main' is normally a non-static function");
4027         }
4028
4029         type_t *type = skip_typeref(entity->declaration.type);
4030         assert(is_type_function(type));
4031
4032         function_type_t *func_type = &type->function;
4033         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4034                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4035                          func_type->return_type);
4036         }
4037         const function_parameter_t *parm = func_type->parameters;
4038         if (parm != NULL) {
4039                 type_t *const first_type        = skip_typeref(parm->type);
4040                 type_t *const first_type_unqual = get_unqualified_type(first_type);
4041                 if (!types_compatible(first_type_unqual, type_int)) {
4042                         warningf(pos,
4043                                  "first argument of 'main' should be 'int', but is '%T'",
4044                                  parm->type);
4045                 }
4046                 parm = parm->next;
4047                 if (parm != NULL) {
4048                         type_t *const second_type = skip_typeref(parm->type);
4049                         type_t *const second_type_unqual
4050                                 = get_unqualified_type(second_type);
4051                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
4052                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'",
4053                                          parm->type);
4054                         }
4055                         parm = parm->next;
4056                         if (parm != NULL) {
4057                                 type_t *const third_type = skip_typeref(parm->type);
4058                                 type_t *const third_type_unqual
4059                                         = get_unqualified_type(third_type);
4060                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
4061                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'",
4062                                                  parm->type);
4063                                 }
4064                                 parm = parm->next;
4065                                 if (parm != NULL)
4066                                         goto warn_arg_count;
4067                         }
4068                 } else {
4069 warn_arg_count:
4070                         warningf(pos, "'main' takes only zero, two or three arguments");
4071                 }
4072         }
4073 }
4074
4075 /**
4076  * Check if a symbol is the equal to "main".
4077  */
4078 static bool is_sym_main(const symbol_t *const sym)
4079 {
4080         return strcmp(sym->string, "main") == 0;
4081 }
4082
4083 static void error_redefined_as_different_kind(const source_position_t *pos,
4084                 const entity_t *old, entity_kind_t new_kind)
4085 {
4086         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4087                get_entity_kind_name(old->kind), old->base.symbol,
4088                get_entity_kind_name(new_kind), &old->base.source_position);
4089 }
4090
4091 static bool is_entity_valid(entity_t *const ent)
4092 {
4093         if (is_declaration(ent)) {
4094                 return is_type_valid(skip_typeref(ent->declaration.type));
4095         } else if (ent->kind == ENTITY_TYPEDEF) {
4096                 return is_type_valid(skip_typeref(ent->typedefe.type));
4097         }
4098         return true;
4099 }
4100
4101 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
4102 {
4103         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
4104                 if (attributes_equal(tattr, attr))
4105                         return true;
4106         }
4107         return false;
4108 }
4109
4110 /**
4111  * test wether new_list contains any attributes not included in old_list
4112  */
4113 static bool has_new_attributes(const attribute_t *old_list,
4114                                const attribute_t *new_list)
4115 {
4116         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
4117                 if (!contains_attribute(old_list, attr))
4118                         return true;
4119         }
4120         return false;
4121 }
4122
4123 /**
4124  * Merge in attributes from an attribute list (probably from a previous
4125  * declaration with the same name). Warning: destroys the old structure
4126  * of the attribute list - don't reuse attributes after this call.
4127  */
4128 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4129 {
4130         attribute_t *next;
4131         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4132                 next = attr->next;
4133                 if (contains_attribute(decl->attributes, attr))
4134                         continue;
4135
4136                 /* move attribute to new declarations attributes list */
4137                 attr->next       = decl->attributes;
4138                 decl->attributes = attr;
4139         }
4140 }
4141
4142 /**
4143  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4144  * for various problems that occur for multiple definitions
4145  */
4146 entity_t *record_entity(entity_t *entity, const bool is_definition)
4147 {
4148         const symbol_t *const    symbol  = entity->base.symbol;
4149         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4150         const source_position_t *pos     = &entity->base.source_position;
4151
4152         /* can happen in error cases */
4153         if (symbol == NULL)
4154                 return entity;
4155
4156         entity_t *const previous_entity = get_entity(symbol, namespc);
4157         /* pushing the same entity twice will break the stack structure */
4158         assert(previous_entity != entity);
4159
4160         if (entity->kind == ENTITY_FUNCTION) {
4161                 type_t *const orig_type = entity->declaration.type;
4162                 type_t *const type      = skip_typeref(orig_type);
4163
4164                 assert(is_type_function(type));
4165                 if (type->function.unspecified_parameters &&
4166                                 warning.strict_prototypes &&
4167                                 previous_entity == NULL) {
4168                         warningf(pos, "function declaration '%#T' is not a prototype",
4169                                          orig_type, symbol);
4170                 }
4171
4172                 if (warning.main && current_scope == file_scope
4173                                 && is_sym_main(symbol)) {
4174                         check_main(entity);
4175                 }
4176         }
4177
4178         if (is_declaration(entity) &&
4179                         warning.nested_externs &&
4180                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4181                         current_scope != file_scope) {
4182                 warningf(pos, "nested extern declaration of '%#T'",
4183                          entity->declaration.type, symbol);
4184         }
4185
4186         if (previous_entity != NULL) {
4187                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4188                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4189                         assert(previous_entity->kind == ENTITY_PARAMETER);
4190                         errorf(pos,
4191                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4192                                         entity->declaration.type, symbol,
4193                                         previous_entity->declaration.type, symbol,
4194                                         &previous_entity->base.source_position);
4195                         goto finish;
4196                 }
4197
4198                 if (previous_entity->base.parent_scope == current_scope) {
4199                         if (previous_entity->kind != entity->kind) {
4200                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4201                                         error_redefined_as_different_kind(pos, previous_entity,
4202                                                         entity->kind);
4203                                 }
4204                                 goto finish;
4205                         }
4206                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4207                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
4208                                                 symbol, &previous_entity->base.source_position);
4209                                 goto finish;
4210                         }
4211                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4212                                 /* TODO: C++ allows this for exactly the same type */
4213                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
4214                                                 symbol, &previous_entity->base.source_position);
4215                                 goto finish;
4216                         }
4217
4218                         /* at this point we should have only VARIABLES or FUNCTIONS */
4219                         assert(is_declaration(previous_entity) && is_declaration(entity));
4220
4221                         declaration_t *const prev_decl = &previous_entity->declaration;
4222                         declaration_t *const decl      = &entity->declaration;
4223
4224                         /* can happen for K&R style declarations */
4225                         if (prev_decl->type       == NULL             &&
4226                                         previous_entity->kind == ENTITY_PARAMETER &&
4227                                         entity->kind          == ENTITY_PARAMETER) {
4228                                 prev_decl->type                   = decl->type;
4229                                 prev_decl->storage_class          = decl->storage_class;
4230                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4231                                 prev_decl->modifiers              = decl->modifiers;
4232                                 return previous_entity;
4233                         }
4234
4235                         type_t *const orig_type = decl->type;
4236                         assert(orig_type != NULL);
4237                         type_t *const type      = skip_typeref(orig_type);
4238                         type_t *const prev_type = skip_typeref(prev_decl->type);
4239
4240                         if (!types_compatible(type, prev_type)) {
4241                                 errorf(pos,
4242                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
4243                                                 orig_type, symbol, prev_decl->type, symbol,
4244                                                 &previous_entity->base.source_position);
4245                         } else {
4246                                 unsigned old_storage_class = prev_decl->storage_class;
4247
4248                                 if (warning.redundant_decls               &&
4249                                                 is_definition                     &&
4250                                                 !prev_decl->used                  &&
4251                                                 !(prev_decl->modifiers & DM_USED) &&
4252                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4253                                         warningf(&previous_entity->base.source_position,
4254                                                         "unnecessary static forward declaration for '%#T'",
4255                                                         prev_decl->type, symbol);
4256                                 }
4257
4258                                 storage_class_t new_storage_class = decl->storage_class;
4259
4260                                 /* pretend no storage class means extern for function
4261                                  * declarations (except if the previous declaration is neither
4262                                  * none nor extern) */
4263                                 if (entity->kind == ENTITY_FUNCTION) {
4264                                         /* the previous declaration could have unspecified parameters or
4265                                          * be a typedef, so use the new type */
4266                                         if (prev_type->function.unspecified_parameters || is_definition)
4267                                                 prev_decl->type = type;
4268
4269                                         switch (old_storage_class) {
4270                                                 case STORAGE_CLASS_NONE:
4271                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4272                                                         /* FALLTHROUGH */
4273
4274                                                 case STORAGE_CLASS_EXTERN:
4275                                                         if (is_definition) {
4276                                                                 if (warning.missing_prototypes &&
4277                                                                                 prev_type->function.unspecified_parameters &&
4278                                                                                 !is_sym_main(symbol)) {
4279                                                                         warningf(pos, "no previous prototype for '%#T'",
4280                                                                                         orig_type, symbol);
4281                                                                 }
4282                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4283                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4284                                                         }
4285                                                         break;
4286
4287                                                 default:
4288                                                         break;
4289                                         }
4290                                 } else if (is_type_incomplete(prev_type)) {
4291                                         prev_decl->type = type;
4292                                 }
4293
4294                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4295                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4296
4297 warn_redundant_declaration: ;
4298                                         bool has_new_attrs
4299                                                 = has_new_attributes(prev_decl->attributes,
4300                                                                      decl->attributes);
4301                                         if (has_new_attrs) {
4302                                                 merge_in_attributes(decl, prev_decl->attributes);
4303                                         } else if (!is_definition        &&
4304                                                         warning.redundant_decls  &&
4305                                                         is_type_valid(prev_type) &&
4306                                                         strcmp(previous_entity->base.source_position.input_name,
4307                                                                 "<builtin>") != 0) {
4308                                                 warningf(pos,
4309                                                          "redundant declaration for '%Y' (declared %P)",
4310                                                          symbol, &previous_entity->base.source_position);
4311                                         }
4312                                 } else if (current_function == NULL) {
4313                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4314                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4315                                                 errorf(pos,
4316                                                        "static declaration of '%Y' follows non-static declaration (declared %P)",
4317                                                        symbol, &previous_entity->base.source_position);
4318                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4319                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4320                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4321                                         } else {
4322                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4323                                                 if (c_mode & _CXX)
4324                                                         goto error_redeclaration;
4325                                                 goto warn_redundant_declaration;
4326                                         }
4327                                 } else if (is_type_valid(prev_type)) {
4328                                         if (old_storage_class == new_storage_class) {
4329 error_redeclaration:
4330                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
4331                                                                 symbol, &previous_entity->base.source_position);
4332                                         } else {
4333                                                 errorf(pos,
4334                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
4335                                                                 symbol, &previous_entity->base.source_position);
4336                                         }
4337                                 }
4338                         }
4339
4340                         prev_decl->modifiers |= decl->modifiers;
4341                         if (entity->kind == ENTITY_FUNCTION) {
4342                                 previous_entity->function.is_inline |= entity->function.is_inline;
4343                         }
4344                         return previous_entity;
4345                 }
4346
4347                 if (warning.shadow ||
4348                                 (warning.shadow_local && previous_entity->base.parent_scope != file_scope)) {
4349                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
4350                                         get_entity_kind_name(entity->kind), symbol,
4351                                         get_entity_kind_name(previous_entity->kind),
4352                                         &previous_entity->base.source_position);
4353                 }
4354         }
4355
4356         if (entity->kind == ENTITY_FUNCTION) {
4357                 if (is_definition &&
4358                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4359                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4360                                 warningf(pos, "no previous prototype for '%#T'",
4361                                          entity->declaration.type, symbol);
4362                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4363                                 warningf(pos, "no previous declaration for '%#T'",
4364                                          entity->declaration.type, symbol);
4365                         }
4366                 }
4367         } else if (warning.missing_declarations &&
4368                         entity->kind == ENTITY_VARIABLE &&
4369                         current_scope == file_scope) {
4370                 declaration_t *declaration = &entity->declaration;
4371                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
4372                         warningf(pos, "no previous declaration for '%#T'",
4373                                  declaration->type, symbol);
4374                 }
4375         }
4376
4377 finish:
4378         assert(entity->base.parent_scope == NULL);
4379         assert(current_scope != NULL);
4380
4381         entity->base.parent_scope = current_scope;
4382         environment_push(entity);
4383         append_entity(current_scope, entity);
4384
4385         return entity;
4386 }
4387
4388 static void parser_error_multiple_definition(entity_t *entity,
4389                 const source_position_t *source_position)
4390 {
4391         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4392                entity->base.symbol, &entity->base.source_position);
4393 }
4394
4395 static bool is_declaration_specifier(const token_t *token,
4396                                      bool only_specifiers_qualifiers)
4397 {
4398         switch (token->type) {
4399                 TYPE_SPECIFIERS
4400                 TYPE_QUALIFIERS
4401                         return true;
4402                 case T_IDENTIFIER:
4403                         return is_typedef_symbol(token->symbol);
4404
4405                 case T___extension__:
4406                 STORAGE_CLASSES
4407                         return !only_specifiers_qualifiers;
4408
4409                 default:
4410                         return false;
4411         }
4412 }
4413
4414 static void parse_init_declarator_rest(entity_t *entity)
4415 {
4416         type_t *orig_type = type_error_type;
4417
4418         if (entity->base.kind == ENTITY_TYPEDEF) {
4419                 errorf(&entity->base.source_position,
4420                        "typedef '%Y' is initialized (use __typeof__ instead)",
4421                        entity->base.symbol);
4422         } else {
4423                 assert(is_declaration(entity));
4424                 orig_type = entity->declaration.type;
4425         }
4426         eat('=');
4427
4428         type_t *type = skip_typeref(orig_type);
4429
4430         if (entity->kind == ENTITY_VARIABLE
4431                         && entity->variable.initializer != NULL) {
4432                 parser_error_multiple_definition(entity, HERE);
4433         }
4434
4435         declaration_t *const declaration = &entity->declaration;
4436         bool must_be_constant = false;
4437         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4438             entity->base.parent_scope  == file_scope) {
4439                 must_be_constant = true;
4440         }
4441
4442         if (is_type_function(type)) {
4443                 errorf(&entity->base.source_position,
4444                        "function '%#T' is initialized like a variable",
4445                        orig_type, entity->base.symbol);
4446                 orig_type = type_error_type;
4447         }
4448
4449         parse_initializer_env_t env;
4450         env.type             = orig_type;
4451         env.must_be_constant = must_be_constant;
4452         env.entity           = entity;
4453         current_init_decl    = entity;
4454
4455         initializer_t *initializer = parse_initializer(&env);
4456         current_init_decl = NULL;
4457
4458         if (entity->kind == ENTITY_VARIABLE) {
4459                 /* §6.7.5:22  array initializers for arrays with unknown size
4460                  * determine the array type size */
4461                 declaration->type            = env.type;
4462                 entity->variable.initializer = initializer;
4463         }
4464 }
4465
4466 /* parse rest of a declaration without any declarator */
4467 static void parse_anonymous_declaration_rest(
4468                 const declaration_specifiers_t *specifiers)
4469 {
4470         eat(';');
4471         anonymous_entity = NULL;
4472
4473         if (warning.other) {
4474                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4475                                 specifiers->thread_local) {
4476                         warningf(&specifiers->source_position,
4477                                  "useless storage class in empty declaration");
4478                 }
4479
4480                 type_t *type = specifiers->type;
4481                 switch (type->kind) {
4482                         case TYPE_COMPOUND_STRUCT:
4483                         case TYPE_COMPOUND_UNION: {
4484                                 if (type->compound.compound->base.symbol == NULL) {
4485                                         warningf(&specifiers->source_position,
4486                                                  "unnamed struct/union that defines no instances");
4487                                 }
4488                                 break;
4489                         }
4490
4491                         case TYPE_ENUM:
4492                                 break;
4493
4494                         default:
4495                                 warningf(&specifiers->source_position, "empty declaration");
4496                                 break;
4497                 }
4498         }
4499 }
4500
4501 static void check_variable_type_complete(entity_t *ent)
4502 {
4503         if (ent->kind != ENTITY_VARIABLE)
4504                 return;
4505
4506         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4507          *         type for the object shall be complete [...] */
4508         declaration_t *decl = &ent->declaration;
4509         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4510                         decl->storage_class == STORAGE_CLASS_STATIC)
4511                 return;
4512
4513         type_t *const orig_type = decl->type;
4514         type_t *const type      = skip_typeref(orig_type);
4515         if (!is_type_incomplete(type))
4516                 return;
4517
4518         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4519          * are given length one. */
4520         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4521                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4522                 return;
4523         }
4524
4525         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
4526                         orig_type, ent->base.symbol);
4527 }
4528
4529
4530 static void parse_declaration_rest(entity_t *ndeclaration,
4531                 const declaration_specifiers_t *specifiers,
4532                 parsed_declaration_func         finished_declaration,
4533                 declarator_flags_t              flags)
4534 {
4535         add_anchor_token(';');
4536         add_anchor_token(',');
4537         while (true) {
4538                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4539
4540                 if (token.type == '=') {
4541                         parse_init_declarator_rest(entity);
4542                 } else if (entity->kind == ENTITY_VARIABLE) {
4543                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4544                          * [...] where the extern specifier is explicitly used. */
4545                         declaration_t *decl = &entity->declaration;
4546                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4547                                 type_t *type = decl->type;
4548                                 if (is_type_reference(skip_typeref(type))) {
4549                                         errorf(&entity->base.source_position,
4550                                                         "reference '%#T' must be initialized",
4551                                                         type, entity->base.symbol);
4552                                 }
4553                         }
4554                 }
4555
4556                 check_variable_type_complete(entity);
4557
4558                 if (!next_if(','))
4559                         break;
4560
4561                 add_anchor_token('=');
4562                 ndeclaration = parse_declarator(specifiers, flags);
4563                 rem_anchor_token('=');
4564         }
4565         expect(';', end_error);
4566
4567 end_error:
4568         anonymous_entity = NULL;
4569         rem_anchor_token(';');
4570         rem_anchor_token(',');
4571 }
4572
4573 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4574 {
4575         symbol_t *symbol = entity->base.symbol;
4576         if (symbol == NULL)
4577                 return entity;
4578
4579         assert(entity->base.namespc == NAMESPACE_NORMAL);
4580         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4581         if (previous_entity == NULL
4582                         || previous_entity->base.parent_scope != current_scope) {
4583                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4584                        symbol);
4585                 return entity;
4586         }
4587
4588         if (is_definition) {
4589                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
4590         }
4591
4592         return record_entity(entity, false);
4593 }
4594
4595 static void parse_declaration(parsed_declaration_func finished_declaration,
4596                               declarator_flags_t      flags)
4597 {
4598         add_anchor_token(';');
4599         declaration_specifiers_t specifiers;
4600         parse_declaration_specifiers(&specifiers);
4601         rem_anchor_token(';');
4602
4603         if (token.type == ';') {
4604                 parse_anonymous_declaration_rest(&specifiers);
4605         } else {
4606                 entity_t *entity = parse_declarator(&specifiers, flags);
4607                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4608         }
4609 }
4610
4611 /* §6.5.2.2:6 */
4612 static type_t *get_default_promoted_type(type_t *orig_type)
4613 {
4614         type_t *result = orig_type;
4615
4616         type_t *type = skip_typeref(orig_type);
4617         if (is_type_integer(type)) {
4618                 result = promote_integer(type);
4619         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4620                 result = type_double;
4621         }
4622
4623         return result;
4624 }
4625
4626 static void parse_kr_declaration_list(entity_t *entity)
4627 {
4628         if (entity->kind != ENTITY_FUNCTION)
4629                 return;
4630
4631         type_t *type = skip_typeref(entity->declaration.type);
4632         assert(is_type_function(type));
4633         if (!type->function.kr_style_parameters)
4634                 return;
4635
4636         add_anchor_token('{');
4637
4638         /* push function parameters */
4639         size_t const  top       = environment_top();
4640         scope_t      *old_scope = scope_push(&entity->function.parameters);
4641
4642         entity_t *parameter = entity->function.parameters.entities;
4643         for ( ; parameter != NULL; parameter = parameter->base.next) {
4644                 assert(parameter->base.parent_scope == NULL);
4645                 parameter->base.parent_scope = current_scope;
4646                 environment_push(parameter);
4647         }
4648
4649         /* parse declaration list */
4650         for (;;) {
4651                 switch (token.type) {
4652                         DECLARATION_START
4653                         case T___extension__:
4654                         /* This covers symbols, which are no type, too, and results in
4655                          * better error messages.  The typical cases are misspelled type
4656                          * names and missing includes. */
4657                         case T_IDENTIFIER:
4658                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4659                                 break;
4660                         default:
4661                                 goto decl_list_end;
4662                 }
4663         }
4664 decl_list_end:
4665
4666         /* pop function parameters */
4667         assert(current_scope == &entity->function.parameters);
4668         scope_pop(old_scope);
4669         environment_pop_to(top);
4670
4671         /* update function type */
4672         type_t *new_type = duplicate_type(type);
4673
4674         function_parameter_t  *parameters = NULL;
4675         function_parameter_t **anchor     = &parameters;
4676
4677         /* did we have an earlier prototype? */
4678         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4679         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4680                 proto_type = NULL;
4681
4682         function_parameter_t *proto_parameter = NULL;
4683         if (proto_type != NULL) {
4684                 type_t *proto_type_type = proto_type->declaration.type;
4685                 proto_parameter         = proto_type_type->function.parameters;
4686                 /* If a K&R function definition has a variadic prototype earlier, then
4687                  * make the function definition variadic, too. This should conform to
4688                  * §6.7.5.3:15 and §6.9.1:8. */
4689                 new_type->function.variadic = proto_type_type->function.variadic;
4690         } else {
4691                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4692                  * prototype */
4693                 new_type->function.unspecified_parameters = true;
4694         }
4695
4696         bool need_incompatible_warning = false;
4697         parameter = entity->function.parameters.entities;
4698         for (; parameter != NULL; parameter = parameter->base.next,
4699                         proto_parameter =
4700                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4701                 if (parameter->kind != ENTITY_PARAMETER)
4702                         continue;
4703
4704                 type_t *parameter_type = parameter->declaration.type;
4705                 if (parameter_type == NULL) {
4706                         if (strict_mode) {
4707                                 errorf(HERE, "no type specified for function parameter '%Y'",
4708                                        parameter->base.symbol);
4709                                 parameter_type = type_error_type;
4710                         } else {
4711                                 if (warning.implicit_int) {
4712                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
4713                                                  parameter->base.symbol);
4714                                 }
4715                                 parameter_type = type_int;
4716                         }
4717                         parameter->declaration.type = parameter_type;
4718                 }
4719
4720                 semantic_parameter_incomplete(parameter);
4721
4722                 /* we need the default promoted types for the function type */
4723                 type_t *not_promoted = parameter_type;
4724                 parameter_type       = get_default_promoted_type(parameter_type);
4725
4726                 /* gcc special: if the type of the prototype matches the unpromoted
4727                  * type don't promote */
4728                 if (!strict_mode && proto_parameter != NULL) {
4729                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4730                         type_t *promo_skip   = skip_typeref(parameter_type);
4731                         type_t *param_skip   = skip_typeref(not_promoted);
4732                         if (!types_compatible(proto_p_type, promo_skip)
4733                                 && types_compatible(proto_p_type, param_skip)) {
4734                                 /* don't promote */
4735                                 need_incompatible_warning = true;
4736                                 parameter_type = not_promoted;
4737                         }
4738                 }
4739                 function_parameter_t *const parameter
4740                         = allocate_parameter(parameter_type);
4741
4742                 *anchor = parameter;
4743                 anchor  = &parameter->next;
4744         }
4745
4746         new_type->function.parameters = parameters;
4747         new_type = identify_new_type(new_type);
4748
4749         if (warning.other && need_incompatible_warning) {
4750                 type_t *proto_type_type = proto_type->declaration.type;
4751                 warningf(HERE,
4752                          "declaration '%#T' is incompatible with '%#T' (declared %P)",
4753                          proto_type_type, proto_type->base.symbol,
4754                          new_type, entity->base.symbol,
4755                          &proto_type->base.source_position);
4756         }
4757
4758         entity->declaration.type = new_type;
4759
4760         rem_anchor_token('{');
4761 }
4762
4763 static bool first_err = true;
4764
4765 /**
4766  * When called with first_err set, prints the name of the current function,
4767  * else does noting.
4768  */
4769 static void print_in_function(void)
4770 {
4771         if (first_err) {
4772                 first_err = false;
4773                 diagnosticf("%s: In function '%Y':\n",
4774                             current_function->base.base.source_position.input_name,
4775                             current_function->base.base.symbol);
4776         }
4777 }
4778
4779 /**
4780  * Check if all labels are defined in the current function.
4781  * Check if all labels are used in the current function.
4782  */
4783 static void check_labels(void)
4784 {
4785         for (const goto_statement_t *goto_statement = goto_first;
4786             goto_statement != NULL;
4787             goto_statement = goto_statement->next) {
4788                 /* skip computed gotos */
4789                 if (goto_statement->expression != NULL)
4790                         continue;
4791
4792                 label_t *label = goto_statement->label;
4793
4794                 label->used = true;
4795                 if (label->base.source_position.input_name == NULL) {
4796                         print_in_function();
4797                         errorf(&goto_statement->base.source_position,
4798                                "label '%Y' used but not defined", label->base.symbol);
4799                  }
4800         }
4801
4802         if (warning.unused_label) {
4803                 for (const label_statement_t *label_statement = label_first;
4804                          label_statement != NULL;
4805                          label_statement = label_statement->next) {
4806                         label_t *label = label_statement->label;
4807
4808                         if (! label->used) {
4809                                 print_in_function();
4810                                 warningf(&label_statement->base.source_position,
4811                                          "label '%Y' defined but not used", label->base.symbol);
4812                         }
4813                 }
4814         }
4815 }
4816
4817 static void warn_unused_entity(entity_t *entity, entity_t *last)
4818 {
4819         entity_t const *const end = last != NULL ? last->base.next : NULL;
4820         for (; entity != end; entity = entity->base.next) {
4821                 if (!is_declaration(entity))
4822                         continue;
4823
4824                 declaration_t *declaration = &entity->declaration;
4825                 if (declaration->implicit)
4826                         continue;
4827
4828                 if (!declaration->used) {
4829                         print_in_function();
4830                         const char *what = get_entity_kind_name(entity->kind);
4831                         warningf(&entity->base.source_position, "%s '%Y' is unused",
4832                                  what, entity->base.symbol);
4833                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4834                         print_in_function();
4835                         const char *what = get_entity_kind_name(entity->kind);
4836                         warningf(&entity->base.source_position, "%s '%Y' is never read",
4837                                  what, entity->base.symbol);
4838                 }
4839         }
4840 }
4841
4842 static void check_unused_variables(statement_t *const stmt, void *const env)
4843 {
4844         (void)env;
4845
4846         switch (stmt->kind) {
4847                 case STATEMENT_DECLARATION: {
4848                         declaration_statement_t const *const decls = &stmt->declaration;
4849                         warn_unused_entity(decls->declarations_begin,
4850                                            decls->declarations_end);
4851                         return;
4852                 }
4853
4854                 case STATEMENT_FOR:
4855                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4856                         return;
4857
4858                 default:
4859                         return;
4860         }
4861 }
4862
4863 /**
4864  * Check declarations of current_function for unused entities.
4865  */
4866 static void check_declarations(void)
4867 {
4868         if (warning.unused_parameter) {
4869                 const scope_t *scope = &current_function->parameters;
4870
4871                 /* do not issue unused warnings for main */
4872                 if (!is_sym_main(current_function->base.base.symbol)) {
4873                         warn_unused_entity(scope->entities, NULL);
4874                 }
4875         }
4876         if (warning.unused_variable) {
4877                 walk_statements(current_function->statement, check_unused_variables,
4878                                 NULL);
4879         }
4880 }
4881
4882 static int determine_truth(expression_t const* const cond)
4883 {
4884         return
4885                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4886                 fold_constant_to_bool(cond)                         ? 1 :
4887                 -1;
4888 }
4889
4890 static void check_reachable(statement_t *);
4891 static bool reaches_end;
4892
4893 static bool expression_returns(expression_t const *const expr)
4894 {
4895         switch (expr->kind) {
4896                 case EXPR_CALL: {
4897                         expression_t const *const func = expr->call.function;
4898                         if (func->kind == EXPR_REFERENCE) {
4899                                 entity_t *entity = func->reference.entity;
4900                                 if (entity->kind == ENTITY_FUNCTION
4901                                                 && entity->declaration.modifiers & DM_NORETURN)
4902                                         return false;
4903                         }
4904
4905                         if (!expression_returns(func))
4906                                 return false;
4907
4908                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4909                                 if (!expression_returns(arg->expression))
4910                                         return false;
4911                         }
4912
4913                         return true;
4914                 }
4915
4916                 case EXPR_REFERENCE:
4917                 case EXPR_REFERENCE_ENUM_VALUE:
4918                 EXPR_LITERAL_CASES
4919                 case EXPR_STRING_LITERAL:
4920                 case EXPR_WIDE_STRING_LITERAL:
4921                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4922                 case EXPR_LABEL_ADDRESS:
4923                 case EXPR_CLASSIFY_TYPE:
4924                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4925                 case EXPR_ALIGNOF:
4926                 case EXPR_FUNCNAME:
4927                 case EXPR_BUILTIN_CONSTANT_P:
4928                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4929                 case EXPR_OFFSETOF:
4930                 case EXPR_INVALID:
4931                         return true;
4932
4933                 case EXPR_STATEMENT: {
4934                         bool old_reaches_end = reaches_end;
4935                         reaches_end = false;
4936                         check_reachable(expr->statement.statement);
4937                         bool returns = reaches_end;
4938                         reaches_end = old_reaches_end;
4939                         return returns;
4940                 }
4941
4942                 case EXPR_CONDITIONAL:
4943                         // TODO handle constant expression
4944
4945                         if (!expression_returns(expr->conditional.condition))
4946                                 return false;
4947
4948                         if (expr->conditional.true_expression != NULL
4949                                         && expression_returns(expr->conditional.true_expression))
4950                                 return true;
4951
4952                         return expression_returns(expr->conditional.false_expression);
4953
4954                 case EXPR_SELECT:
4955                         return expression_returns(expr->select.compound);
4956
4957                 case EXPR_ARRAY_ACCESS:
4958                         return
4959                                 expression_returns(expr->array_access.array_ref) &&
4960                                 expression_returns(expr->array_access.index);
4961
4962                 case EXPR_VA_START:
4963                         return expression_returns(expr->va_starte.ap);
4964
4965                 case EXPR_VA_ARG:
4966                         return expression_returns(expr->va_arge.ap);
4967
4968                 case EXPR_VA_COPY:
4969                         return expression_returns(expr->va_copye.src);
4970
4971                 EXPR_UNARY_CASES_MANDATORY
4972                         return expression_returns(expr->unary.value);
4973
4974                 case EXPR_UNARY_THROW:
4975                         return false;
4976
4977                 EXPR_BINARY_CASES
4978                         // TODO handle constant lhs of && and ||
4979                         return
4980                                 expression_returns(expr->binary.left) &&
4981                                 expression_returns(expr->binary.right);
4982
4983                 case EXPR_UNKNOWN:
4984                         break;
4985         }
4986
4987         panic("unhandled expression");
4988 }
4989
4990 static bool initializer_returns(initializer_t const *const init)
4991 {
4992         switch (init->kind) {
4993                 case INITIALIZER_VALUE:
4994                         return expression_returns(init->value.value);
4995
4996                 case INITIALIZER_LIST: {
4997                         initializer_t * const*       i       = init->list.initializers;
4998                         initializer_t * const* const end     = i + init->list.len;
4999                         bool                         returns = true;
5000                         for (; i != end; ++i) {
5001                                 if (!initializer_returns(*i))
5002                                         returns = false;
5003                         }
5004                         return returns;
5005                 }
5006
5007                 case INITIALIZER_STRING:
5008                 case INITIALIZER_WIDE_STRING:
5009                 case INITIALIZER_DESIGNATOR: // designators have no payload
5010                         return true;
5011         }
5012         panic("unhandled initializer");
5013 }
5014
5015 static bool noreturn_candidate;
5016
5017 static void check_reachable(statement_t *const stmt)
5018 {
5019         if (stmt->base.reachable)
5020                 return;
5021         if (stmt->kind != STATEMENT_DO_WHILE)
5022                 stmt->base.reachable = true;
5023
5024         statement_t *last = stmt;
5025         statement_t *next;
5026         switch (stmt->kind) {
5027                 case STATEMENT_INVALID:
5028                 case STATEMENT_EMPTY:
5029                 case STATEMENT_ASM:
5030                         next = stmt->base.next;
5031                         break;
5032
5033                 case STATEMENT_DECLARATION: {
5034                         declaration_statement_t const *const decl = &stmt->declaration;
5035                         entity_t                const *      ent  = decl->declarations_begin;
5036                         entity_t                const *const last = decl->declarations_end;
5037                         if (ent != NULL) {
5038                                 for (;; ent = ent->base.next) {
5039                                         if (ent->kind                 == ENTITY_VARIABLE &&
5040                                                         ent->variable.initializer != NULL            &&
5041                                                         !initializer_returns(ent->variable.initializer)) {
5042                                                 return;
5043                                         }
5044                                         if (ent == last)
5045                                                 break;
5046                                 }
5047                         }
5048                         next = stmt->base.next;
5049                         break;
5050                 }
5051
5052                 case STATEMENT_COMPOUND:
5053                         next = stmt->compound.statements;
5054                         if (next == NULL)
5055                                 next = stmt->base.next;
5056                         break;
5057
5058                 case STATEMENT_RETURN: {
5059                         expression_t const *const val = stmt->returns.value;
5060                         if (val == NULL || expression_returns(val))
5061                                 noreturn_candidate = false;
5062                         return;
5063                 }
5064
5065                 case STATEMENT_IF: {
5066                         if_statement_t const *const ifs  = &stmt->ifs;
5067                         expression_t   const *const cond = ifs->condition;
5068
5069                         if (!expression_returns(cond))
5070                                 return;
5071
5072                         int const val = determine_truth(cond);
5073
5074                         if (val >= 0)
5075                                 check_reachable(ifs->true_statement);
5076
5077                         if (val > 0)
5078                                 return;
5079
5080                         if (ifs->false_statement != NULL) {
5081                                 check_reachable(ifs->false_statement);
5082                                 return;
5083                         }
5084
5085                         next = stmt->base.next;
5086                         break;
5087                 }
5088
5089                 case STATEMENT_SWITCH: {
5090                         switch_statement_t const *const switchs = &stmt->switchs;
5091                         expression_t       const *const expr    = switchs->expression;
5092
5093                         if (!expression_returns(expr))
5094                                 return;
5095
5096                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
5097                                 long                    const val      = fold_constant_to_int(expr);
5098                                 case_label_statement_t *      defaults = NULL;
5099                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5100                                         if (i->expression == NULL) {
5101                                                 defaults = i;
5102                                                 continue;
5103                                         }
5104
5105                                         if (i->first_case <= val && val <= i->last_case) {
5106                                                 check_reachable((statement_t*)i);
5107                                                 return;
5108                                         }
5109                                 }
5110
5111                                 if (defaults != NULL) {
5112                                         check_reachable((statement_t*)defaults);
5113                                         return;
5114                                 }
5115                         } else {
5116                                 bool has_default = false;
5117                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5118                                         if (i->expression == NULL)
5119                                                 has_default = true;
5120
5121                                         check_reachable((statement_t*)i);
5122                                 }
5123
5124                                 if (has_default)
5125                                         return;
5126                         }
5127
5128                         next = stmt->base.next;
5129                         break;
5130                 }
5131
5132                 case STATEMENT_EXPRESSION: {
5133                         /* Check for noreturn function call */
5134                         expression_t const *const expr = stmt->expression.expression;
5135                         if (!expression_returns(expr))
5136                                 return;
5137
5138                         next = stmt->base.next;
5139                         break;
5140                 }
5141
5142                 case STATEMENT_CONTINUE:
5143                         for (statement_t *parent = stmt;;) {
5144                                 parent = parent->base.parent;
5145                                 if (parent == NULL) /* continue not within loop */
5146                                         return;
5147
5148                                 next = parent;
5149                                 switch (parent->kind) {
5150                                         case STATEMENT_WHILE:    goto continue_while;
5151                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5152                                         case STATEMENT_FOR:      goto continue_for;
5153
5154                                         default: break;
5155                                 }
5156                         }
5157
5158                 case STATEMENT_BREAK:
5159                         for (statement_t *parent = stmt;;) {
5160                                 parent = parent->base.parent;
5161                                 if (parent == NULL) /* break not within loop/switch */
5162                                         return;
5163
5164                                 switch (parent->kind) {
5165                                         case STATEMENT_SWITCH:
5166                                         case STATEMENT_WHILE:
5167                                         case STATEMENT_DO_WHILE:
5168                                         case STATEMENT_FOR:
5169                                                 last = parent;
5170                                                 next = parent->base.next;
5171                                                 goto found_break_parent;
5172
5173                                         default: break;
5174                                 }
5175                         }
5176 found_break_parent:
5177                         break;
5178
5179                 case STATEMENT_GOTO:
5180                         if (stmt->gotos.expression) {
5181                                 if (!expression_returns(stmt->gotos.expression))
5182                                         return;
5183
5184                                 statement_t *parent = stmt->base.parent;
5185                                 if (parent == NULL) /* top level goto */
5186                                         return;
5187                                 next = parent;
5188                         } else {
5189                                 next = stmt->gotos.label->statement;
5190                                 if (next == NULL) /* missing label */
5191                                         return;
5192                         }
5193                         break;
5194
5195                 case STATEMENT_LABEL:
5196                         next = stmt->label.statement;
5197                         break;
5198
5199                 case STATEMENT_CASE_LABEL:
5200                         next = stmt->case_label.statement;
5201                         break;
5202
5203                 case STATEMENT_WHILE: {
5204                         while_statement_t const *const whiles = &stmt->whiles;
5205                         expression_t      const *const cond   = whiles->condition;
5206
5207                         if (!expression_returns(cond))
5208                                 return;
5209
5210                         int const val = determine_truth(cond);
5211
5212                         if (val >= 0)
5213                                 check_reachable(whiles->body);
5214
5215                         if (val > 0)
5216                                 return;
5217
5218                         next = stmt->base.next;
5219                         break;
5220                 }
5221
5222                 case STATEMENT_DO_WHILE:
5223                         next = stmt->do_while.body;
5224                         break;
5225
5226                 case STATEMENT_FOR: {
5227                         for_statement_t *const fors = &stmt->fors;
5228
5229                         if (fors->condition_reachable)
5230                                 return;
5231                         fors->condition_reachable = true;
5232
5233                         expression_t const *const cond = fors->condition;
5234
5235                         int val;
5236                         if (cond == NULL) {
5237                                 val = 1;
5238                         } else if (expression_returns(cond)) {
5239                                 val = determine_truth(cond);
5240                         } else {
5241                                 return;
5242                         }
5243
5244                         if (val >= 0)
5245                                 check_reachable(fors->body);
5246
5247                         if (val > 0)
5248                                 return;
5249
5250                         next = stmt->base.next;
5251                         break;
5252                 }
5253
5254                 case STATEMENT_MS_TRY: {
5255                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5256                         check_reachable(ms_try->try_statement);
5257                         next = ms_try->final_statement;
5258                         break;
5259                 }
5260
5261                 case STATEMENT_LEAVE: {
5262                         statement_t *parent = stmt;
5263                         for (;;) {
5264                                 parent = parent->base.parent;
5265                                 if (parent == NULL) /* __leave not within __try */
5266                                         return;
5267
5268                                 if (parent->kind == STATEMENT_MS_TRY) {
5269                                         last = parent;
5270                                         next = parent->ms_try.final_statement;
5271                                         break;
5272                                 }
5273                         }
5274                         break;
5275                 }
5276
5277                 default:
5278                         panic("invalid statement kind");
5279         }
5280
5281         while (next == NULL) {
5282                 next = last->base.parent;
5283                 if (next == NULL) {
5284                         noreturn_candidate = false;
5285
5286                         type_t *const type = skip_typeref(current_function->base.type);
5287                         assert(is_type_function(type));
5288                         type_t *const ret  = skip_typeref(type->function.return_type);
5289                         if (warning.return_type                    &&
5290                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5291                             is_type_valid(ret)                     &&
5292                             !is_sym_main(current_function->base.base.symbol)) {
5293                                 warningf(&stmt->base.source_position,
5294                                          "control reaches end of non-void function");
5295                         }
5296                         return;
5297                 }
5298
5299                 switch (next->kind) {
5300                         case STATEMENT_INVALID:
5301                         case STATEMENT_EMPTY:
5302                         case STATEMENT_DECLARATION:
5303                         case STATEMENT_EXPRESSION:
5304                         case STATEMENT_ASM:
5305                         case STATEMENT_RETURN:
5306                         case STATEMENT_CONTINUE:
5307                         case STATEMENT_BREAK:
5308                         case STATEMENT_GOTO:
5309                         case STATEMENT_LEAVE:
5310                                 panic("invalid control flow in function");
5311
5312                         case STATEMENT_COMPOUND:
5313                                 if (next->compound.stmt_expr) {
5314                                         reaches_end = true;
5315                                         return;
5316                                 }
5317                                 /* FALLTHROUGH */
5318                         case STATEMENT_IF:
5319                         case STATEMENT_SWITCH:
5320                         case STATEMENT_LABEL:
5321                         case STATEMENT_CASE_LABEL:
5322                                 last = next;
5323                                 next = next->base.next;
5324                                 break;
5325
5326                         case STATEMENT_WHILE: {
5327 continue_while:
5328                                 if (next->base.reachable)
5329                                         return;
5330                                 next->base.reachable = true;
5331
5332                                 while_statement_t const *const whiles = &next->whiles;
5333                                 expression_t      const *const cond   = whiles->condition;
5334
5335                                 if (!expression_returns(cond))
5336                                         return;
5337
5338                                 int const val = determine_truth(cond);
5339
5340                                 if (val >= 0)
5341                                         check_reachable(whiles->body);
5342
5343                                 if (val > 0)
5344                                         return;
5345
5346                                 last = next;
5347                                 next = next->base.next;
5348                                 break;
5349                         }
5350
5351                         case STATEMENT_DO_WHILE: {
5352 continue_do_while:
5353                                 if (next->base.reachable)
5354                                         return;
5355                                 next->base.reachable = true;
5356
5357                                 do_while_statement_t const *const dw   = &next->do_while;
5358                                 expression_t         const *const cond = dw->condition;
5359
5360                                 if (!expression_returns(cond))
5361                                         return;
5362
5363                                 int const val = determine_truth(cond);
5364
5365                                 if (val >= 0)
5366                                         check_reachable(dw->body);
5367
5368                                 if (val > 0)
5369                                         return;
5370
5371                                 last = next;
5372                                 next = next->base.next;
5373                                 break;
5374                         }
5375
5376                         case STATEMENT_FOR: {
5377 continue_for:;
5378                                 for_statement_t *const fors = &next->fors;
5379
5380                                 fors->step_reachable = true;
5381
5382                                 if (fors->condition_reachable)
5383                                         return;
5384                                 fors->condition_reachable = true;
5385
5386                                 expression_t const *const cond = fors->condition;
5387
5388                                 int val;
5389                                 if (cond == NULL) {
5390                                         val = 1;
5391                                 } else if (expression_returns(cond)) {
5392                                         val = determine_truth(cond);
5393                                 } else {
5394                                         return;
5395                                 }
5396
5397                                 if (val >= 0)
5398                                         check_reachable(fors->body);
5399
5400                                 if (val > 0)
5401                                         return;
5402
5403                                 last = next;
5404                                 next = next->base.next;
5405                                 break;
5406                         }
5407
5408                         case STATEMENT_MS_TRY:
5409                                 last = next;
5410                                 next = next->ms_try.final_statement;
5411                                 break;
5412                 }
5413         }
5414
5415         check_reachable(next);
5416 }
5417
5418 static void check_unreachable(statement_t* const stmt, void *const env)
5419 {
5420         (void)env;
5421
5422         switch (stmt->kind) {
5423                 case STATEMENT_DO_WHILE:
5424                         if (!stmt->base.reachable) {
5425                                 expression_t const *const cond = stmt->do_while.condition;
5426                                 if (determine_truth(cond) >= 0) {
5427                                         warningf(&cond->base.source_position,
5428                                                  "condition of do-while-loop is unreachable");
5429                                 }
5430                         }
5431                         return;
5432
5433                 case STATEMENT_FOR: {
5434                         for_statement_t const* const fors = &stmt->fors;
5435
5436                         // if init and step are unreachable, cond is unreachable, too
5437                         if (!stmt->base.reachable && !fors->step_reachable) {
5438                                 warningf(&stmt->base.source_position, "statement is unreachable");
5439                         } else {
5440                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5441                                         warningf(&fors->initialisation->base.source_position,
5442                                                  "initialisation of for-statement is unreachable");
5443                                 }
5444
5445                                 if (!fors->condition_reachable && fors->condition != NULL) {
5446                                         warningf(&fors->condition->base.source_position,
5447                                                  "condition of for-statement is unreachable");
5448                                 }
5449
5450                                 if (!fors->step_reachable && fors->step != NULL) {
5451                                         warningf(&fors->step->base.source_position,
5452                                                  "step of for-statement is unreachable");
5453                                 }
5454                         }
5455                         return;
5456                 }
5457
5458                 case STATEMENT_COMPOUND:
5459                         if (stmt->compound.statements != NULL)
5460                                 return;
5461                         goto warn_unreachable;
5462
5463                 case STATEMENT_DECLARATION: {
5464                         /* Only warn if there is at least one declarator with an initializer.
5465                          * This typically occurs in switch statements. */
5466                         declaration_statement_t const *const decl = &stmt->declaration;
5467                         entity_t                const *      ent  = decl->declarations_begin;
5468                         entity_t                const *const last = decl->declarations_end;
5469                         if (ent != NULL) {
5470                                 for (;; ent = ent->base.next) {
5471                                         if (ent->kind                 == ENTITY_VARIABLE &&
5472                                                         ent->variable.initializer != NULL) {
5473                                                 goto warn_unreachable;
5474                                         }
5475                                         if (ent == last)
5476                                                 return;
5477                                 }
5478                         }
5479                 }
5480
5481                 default:
5482 warn_unreachable:
5483                         if (!stmt->base.reachable)
5484                                 warningf(&stmt->base.source_position, "statement is unreachable");
5485                         return;
5486         }
5487 }
5488
5489 static void parse_external_declaration(void)
5490 {
5491         /* function-definitions and declarations both start with declaration
5492          * specifiers */
5493         add_anchor_token(';');
5494         declaration_specifiers_t specifiers;
5495         parse_declaration_specifiers(&specifiers);
5496         rem_anchor_token(';');
5497
5498         /* must be a declaration */
5499         if (token.type == ';') {
5500                 parse_anonymous_declaration_rest(&specifiers);
5501                 return;
5502         }
5503
5504         add_anchor_token(',');
5505         add_anchor_token('=');
5506         add_anchor_token(';');
5507         add_anchor_token('{');
5508
5509         /* declarator is common to both function-definitions and declarations */
5510         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5511
5512         rem_anchor_token('{');
5513         rem_anchor_token(';');
5514         rem_anchor_token('=');
5515         rem_anchor_token(',');
5516
5517         /* must be a declaration */
5518         switch (token.type) {
5519                 case ',':
5520                 case ';':
5521                 case '=':
5522                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5523                                         DECL_FLAGS_NONE);
5524                         return;
5525         }
5526
5527         /* must be a function definition */
5528         parse_kr_declaration_list(ndeclaration);
5529
5530         if (token.type != '{') {
5531                 parse_error_expected("while parsing function definition", '{', NULL);
5532                 eat_until_matching_token(';');
5533                 return;
5534         }
5535
5536         assert(is_declaration(ndeclaration));
5537         type_t *const orig_type = ndeclaration->declaration.type;
5538         type_t *      type      = skip_typeref(orig_type);
5539
5540         if (!is_type_function(type)) {
5541                 if (is_type_valid(type)) {
5542                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5543                                type, ndeclaration->base.symbol);
5544                 }
5545                 eat_block();
5546                 return;
5547         } else if (is_typeref(orig_type)) {
5548                 /* §6.9.1:2 */
5549                 errorf(&ndeclaration->base.source_position,
5550                                 "type of function definition '%#T' is a typedef",
5551                                 orig_type, ndeclaration->base.symbol);
5552         }
5553
5554         if (warning.aggregate_return &&
5555             is_type_compound(skip_typeref(type->function.return_type))) {
5556                 warningf(&ndeclaration->base.source_position, "function '%Y' returns an aggregate",
5557                          ndeclaration->base.symbol);
5558         }
5559         if (warning.traditional && !type->function.unspecified_parameters) {
5560                 warningf(&ndeclaration->base.source_position, "traditional C rejects ISO C style function definition of function '%Y'",
5561                         ndeclaration->base.symbol);
5562         }
5563         if (warning.old_style_definition && type->function.unspecified_parameters) {
5564                 warningf(&ndeclaration->base.source_position, "old-style function definition '%Y'",
5565                         ndeclaration->base.symbol);
5566         }
5567
5568         /* §6.7.5.3:14 a function definition with () means no
5569          * parameters (and not unspecified parameters) */
5570         if (type->function.unspecified_parameters &&
5571                         type->function.parameters == NULL) {
5572                 type_t *copy                          = duplicate_type(type);
5573                 copy->function.unspecified_parameters = false;
5574                 type                                  = identify_new_type(copy);
5575
5576                 ndeclaration->declaration.type = type;
5577         }
5578
5579         entity_t *const entity = record_entity(ndeclaration, true);
5580         assert(entity->kind == ENTITY_FUNCTION);
5581         assert(ndeclaration->kind == ENTITY_FUNCTION);
5582
5583         function_t *const function = &entity->function;
5584         if (ndeclaration != entity) {
5585                 function->parameters = ndeclaration->function.parameters;
5586         }
5587         assert(is_declaration(entity));
5588         type = skip_typeref(entity->declaration.type);
5589
5590         /* push function parameters and switch scope */
5591         size_t const  top       = environment_top();
5592         scope_t      *old_scope = scope_push(&function->parameters);
5593
5594         entity_t *parameter = function->parameters.entities;
5595         for (; parameter != NULL; parameter = parameter->base.next) {
5596                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5597                         parameter->base.parent_scope = current_scope;
5598                 }
5599                 assert(parameter->base.parent_scope == NULL
5600                                 || parameter->base.parent_scope == current_scope);
5601                 parameter->base.parent_scope = current_scope;
5602                 if (parameter->base.symbol == NULL) {
5603                         errorf(&parameter->base.source_position, "parameter name omitted");
5604                         continue;
5605                 }
5606                 environment_push(parameter);
5607         }
5608
5609         if (function->statement != NULL) {
5610                 parser_error_multiple_definition(entity, HERE);
5611                 eat_block();
5612         } else {
5613                 /* parse function body */
5614                 int         label_stack_top      = label_top();
5615                 function_t *old_current_function = current_function;
5616                 entity_t   *old_current_entity   = current_entity;
5617                 current_function                 = function;
5618                 current_entity                   = entity;
5619                 current_parent                   = NULL;
5620
5621                 goto_first   = NULL;
5622                 goto_anchor  = &goto_first;
5623                 label_first  = NULL;
5624                 label_anchor = &label_first;
5625
5626                 statement_t *const body = parse_compound_statement(false);
5627                 function->statement = body;
5628                 first_err = true;
5629                 check_labels();
5630                 check_declarations();
5631                 if (warning.return_type      ||
5632                     warning.unreachable_code ||
5633                     (warning.missing_noreturn
5634                      && !(function->base.modifiers & DM_NORETURN))) {
5635                         noreturn_candidate = true;
5636                         check_reachable(body);
5637                         if (warning.unreachable_code)
5638                                 walk_statements(body, check_unreachable, NULL);
5639                         if (warning.missing_noreturn &&
5640                             noreturn_candidate       &&
5641                             !(function->base.modifiers & DM_NORETURN)) {
5642                                 warningf(&body->base.source_position,
5643                                          "function '%#T' is candidate for attribute 'noreturn'",
5644                                          type, entity->base.symbol);
5645                         }
5646                 }
5647
5648                 assert(current_parent   == NULL);
5649                 assert(current_function == function);
5650                 assert(current_entity   == entity);
5651                 current_entity   = old_current_entity;
5652                 current_function = old_current_function;
5653                 label_pop_to(label_stack_top);
5654         }
5655
5656         assert(current_scope == &function->parameters);
5657         scope_pop(old_scope);
5658         environment_pop_to(top);
5659 }
5660
5661 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5662                                   source_position_t *source_position,
5663                                   const symbol_t *symbol)
5664 {
5665         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5666
5667         type->bitfield.base_type       = base_type;
5668         type->bitfield.size_expression = size;
5669
5670         il_size_t bit_size;
5671         type_t *skipped_type = skip_typeref(base_type);
5672         if (!is_type_integer(skipped_type)) {
5673                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5674                        base_type);
5675                 bit_size = 0;
5676         } else {
5677                 bit_size = get_type_size(base_type) * 8;
5678         }
5679
5680         if (is_constant_expression(size) == EXPR_CLASS_CONSTANT) {
5681                 long v = fold_constant_to_int(size);
5682                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5683
5684                 if (v < 0) {
5685                         errorf(source_position, "negative width in bit-field '%Y'",
5686                                user_symbol);
5687                 } else if (v == 0 && symbol != NULL) {
5688                         errorf(source_position, "zero width for bit-field '%Y'",
5689                                user_symbol);
5690                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5691                         errorf(source_position, "width of '%Y' exceeds its type",
5692                                user_symbol);
5693                 } else {
5694                         type->bitfield.bit_size = v;
5695                 }
5696         }
5697
5698         return type;
5699 }
5700
5701 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5702 {
5703         entity_t *iter = compound->members.entities;
5704         for (; iter != NULL; iter = iter->base.next) {
5705                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5706                         continue;
5707
5708                 if (iter->base.symbol == symbol) {
5709                         return iter;
5710                 } else if (iter->base.symbol == NULL) {
5711                         /* search in anonymous structs and unions */
5712                         type_t *type = skip_typeref(iter->declaration.type);
5713                         if (is_type_compound(type)) {
5714                                 if (find_compound_entry(type->compound.compound, symbol)
5715                                                 != NULL)
5716                                         return iter;
5717                         }
5718                         continue;
5719                 }
5720         }
5721
5722         return NULL;
5723 }
5724
5725 static void check_deprecated(const source_position_t *source_position,
5726                              const entity_t *entity)
5727 {
5728         if (!warning.deprecated_declarations)
5729                 return;
5730         if (!is_declaration(entity))
5731                 return;
5732         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5733                 return;
5734
5735         char const *const prefix = get_entity_kind_name(entity->kind);
5736         const char *deprecated_string
5737                         = get_deprecated_string(entity->declaration.attributes);
5738         if (deprecated_string != NULL) {
5739                 warningf(source_position, "%s '%Y' is deprecated (declared %P): \"%s\"",
5740                                  prefix, entity->base.symbol, &entity->base.source_position,
5741                                  deprecated_string);
5742         } else {
5743                 warningf(source_position, "%s '%Y' is deprecated (declared %P)", prefix,
5744                                  entity->base.symbol, &entity->base.source_position);
5745         }
5746 }
5747
5748
5749 static expression_t *create_select(const source_position_t *pos,
5750                                    expression_t *addr,
5751                                    type_qualifiers_t qualifiers,
5752                                                                    entity_t *entry)
5753 {
5754         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5755
5756         check_deprecated(pos, entry);
5757
5758         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5759         select->select.compound       = addr;
5760         select->select.compound_entry = entry;
5761
5762         type_t *entry_type = entry->declaration.type;
5763         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5764
5765         /* we always do the auto-type conversions; the & and sizeof parser contains
5766          * code to revert this! */
5767         select->base.type = automatic_type_conversion(res_type);
5768         if (res_type->kind == TYPE_BITFIELD) {
5769                 select->base.type = res_type->bitfield.base_type;
5770         }
5771
5772         return select;
5773 }
5774
5775 /**
5776  * Find entry with symbol in compound. Search anonymous structs and unions and
5777  * creates implicit select expressions for them.
5778  * Returns the adress for the innermost compound.
5779  */
5780 static expression_t *find_create_select(const source_position_t *pos,
5781                                         expression_t *addr,
5782                                         type_qualifiers_t qualifiers,
5783                                         compound_t *compound, symbol_t *symbol)
5784 {
5785         entity_t *iter = compound->members.entities;
5786         for (; iter != NULL; iter = iter->base.next) {
5787                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5788                         continue;
5789
5790                 symbol_t *iter_symbol = iter->base.symbol;
5791                 if (iter_symbol == NULL) {
5792                         type_t *type = iter->declaration.type;
5793                         if (type->kind != TYPE_COMPOUND_STRUCT
5794                                         && type->kind != TYPE_COMPOUND_UNION)
5795                                 continue;
5796
5797                         compound_t *sub_compound = type->compound.compound;
5798
5799                         if (find_compound_entry(sub_compound, symbol) == NULL)
5800                                 continue;
5801
5802                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5803                         sub_addr->base.source_position = *pos;
5804                         sub_addr->select.implicit      = true;
5805                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5806                                                   symbol);
5807                 }
5808
5809                 if (iter_symbol == symbol) {
5810                         return create_select(pos, addr, qualifiers, iter);
5811                 }
5812         }
5813
5814         return NULL;
5815 }
5816
5817 static void parse_compound_declarators(compound_t *compound,
5818                 const declaration_specifiers_t *specifiers)
5819 {
5820         do {
5821                 entity_t *entity;
5822
5823                 if (token.type == ':') {
5824                         source_position_t source_position = *HERE;
5825                         next_token();
5826
5827                         type_t *base_type = specifiers->type;
5828                         expression_t *size = parse_constant_expression();
5829
5830                         type_t *type = make_bitfield_type(base_type, size,
5831                                         &source_position, NULL);
5832
5833                         attribute_t  *attributes = parse_attributes(NULL);
5834                         attribute_t **anchor     = &attributes;
5835                         while (*anchor != NULL)
5836                                 anchor = &(*anchor)->next;
5837                         *anchor = specifiers->attributes;
5838
5839                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL);
5840                         entity->base.source_position               = source_position;
5841                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5842                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5843                         entity->declaration.type                   = type;
5844                         entity->declaration.attributes             = attributes;
5845
5846                         if (attributes != NULL) {
5847                                 handle_entity_attributes(attributes, entity);
5848                         }
5849                         append_entity(&compound->members, entity);
5850                 } else {
5851                         entity = parse_declarator(specifiers,
5852                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5853                         if (entity->kind == ENTITY_TYPEDEF) {
5854                                 errorf(&entity->base.source_position,
5855                                                 "typedef not allowed as compound member");
5856                         } else {
5857                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5858
5859                                 /* make sure we don't define a symbol multiple times */
5860                                 symbol_t *symbol = entity->base.symbol;
5861                                 if (symbol != NULL) {
5862                                         entity_t *prev = find_compound_entry(compound, symbol);
5863                                         if (prev != NULL) {
5864                                                 errorf(&entity->base.source_position,
5865                                                                 "multiple declarations of symbol '%Y' (declared %P)",
5866                                                                 symbol, &prev->base.source_position);
5867                                         }
5868                                 }
5869
5870                                 if (token.type == ':') {
5871                                         source_position_t source_position = *HERE;
5872                                         next_token();
5873                                         expression_t *size = parse_constant_expression();
5874
5875                                         type_t *type          = entity->declaration.type;
5876                                         type_t *bitfield_type = make_bitfield_type(type, size,
5877                                                         &source_position, entity->base.symbol);
5878
5879                                         attribute_t *attributes = parse_attributes(NULL);
5880                                         entity->declaration.type = bitfield_type;
5881                                         handle_entity_attributes(attributes, entity);
5882                                 } else {
5883                                         type_t *orig_type = entity->declaration.type;
5884                                         type_t *type      = skip_typeref(orig_type);
5885                                         if (is_type_function(type)) {
5886                                                 errorf(&entity->base.source_position,
5887                                                        "compound member '%Y' must not have function type '%T'",
5888                                                                 entity->base.symbol, orig_type);
5889                                         } else if (is_type_incomplete(type)) {
5890                                                 /* §6.7.2.1:16 flexible array member */
5891                                                 if (!is_type_array(type)       ||
5892                                                                 token.type          != ';' ||
5893                                                                 look_ahead(1)->type != '}') {
5894                                                         errorf(&entity->base.source_position,
5895                                                                "compound member '%Y' has incomplete type '%T'",
5896                                                                         entity->base.symbol, orig_type);
5897                                                 }
5898                                         }
5899                                 }
5900
5901                                 append_entity(&compound->members, entity);
5902                         }
5903                 }
5904         } while (next_if(','));
5905         expect(';', end_error);
5906
5907 end_error:
5908         anonymous_entity = NULL;
5909 }
5910
5911 static void parse_compound_type_entries(compound_t *compound)
5912 {
5913         eat('{');
5914         add_anchor_token('}');
5915
5916         while (token.type != '}') {
5917                 if (token.type == T_EOF) {
5918                         errorf(HERE, "EOF while parsing struct");
5919                         break;
5920                 }
5921                 declaration_specifiers_t specifiers;
5922                 parse_declaration_specifiers(&specifiers);
5923                 parse_compound_declarators(compound, &specifiers);
5924         }
5925         rem_anchor_token('}');
5926         next_token();
5927
5928         /* §6.7.2.1:7 */
5929         compound->complete = true;
5930 }
5931
5932 static type_t *parse_typename(void)
5933 {
5934         declaration_specifiers_t specifiers;
5935         parse_declaration_specifiers(&specifiers);
5936         if (specifiers.storage_class != STORAGE_CLASS_NONE
5937                         || specifiers.thread_local) {
5938                 /* TODO: improve error message, user does probably not know what a
5939                  * storage class is...
5940                  */
5941                 errorf(HERE, "typename must not have a storage class");
5942         }
5943
5944         type_t *result = parse_abstract_declarator(specifiers.type);
5945
5946         return result;
5947 }
5948
5949
5950
5951
5952 typedef expression_t* (*parse_expression_function)(void);
5953 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5954
5955 typedef struct expression_parser_function_t expression_parser_function_t;
5956 struct expression_parser_function_t {
5957         parse_expression_function        parser;
5958         precedence_t                     infix_precedence;
5959         parse_expression_infix_function  infix_parser;
5960 };
5961
5962 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5963
5964 /**
5965  * Prints an error message if an expression was expected but not read
5966  */
5967 static expression_t *expected_expression_error(void)
5968 {
5969         /* skip the error message if the error token was read */
5970         if (token.type != T_ERROR) {
5971                 errorf(HERE, "expected expression, got token %K", &token);
5972         }
5973         next_token();
5974
5975         return create_invalid_expression();
5976 }
5977
5978 static type_t *get_string_type(void)
5979 {
5980         return warning.write_strings ? type_const_char_ptr : type_char_ptr;
5981 }
5982
5983 static type_t *get_wide_string_type(void)
5984 {
5985         return warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5986 }
5987
5988 /**
5989  * Parse a string constant.
5990  */
5991 static expression_t *parse_string_literal(void)
5992 {
5993         source_position_t begin   = token.source_position;
5994         string_t          res     = token.literal;
5995         bool              is_wide = (token.type == T_WIDE_STRING_LITERAL);
5996
5997         next_token();
5998         while (token.type == T_STRING_LITERAL
5999                         || token.type == T_WIDE_STRING_LITERAL) {
6000                 warn_string_concat(&token.source_position);
6001                 res = concat_strings(&res, &token.literal);
6002                 next_token();
6003                 is_wide |= token.type == T_WIDE_STRING_LITERAL;
6004         }
6005
6006         expression_t *literal;
6007         if (is_wide) {
6008                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6009                 literal->base.type = get_wide_string_type();
6010         } else {
6011                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
6012                 literal->base.type = get_string_type();
6013         }
6014         literal->base.source_position = begin;
6015         literal->literal.value        = res;
6016
6017         return literal;
6018 }
6019
6020 /**
6021  * Parse a boolean constant.
6022  */
6023 static expression_t *parse_boolean_literal(bool value)
6024 {
6025         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
6026         literal->base.source_position = token.source_position;
6027         literal->base.type            = type_bool;
6028         literal->literal.value.begin  = value ? "true" : "false";
6029         literal->literal.value.size   = value ? 4 : 5;
6030
6031         next_token();
6032         return literal;
6033 }
6034
6035 static void warn_traditional_suffix(void)
6036 {
6037         if (!warning.traditional)
6038                 return;
6039         warningf(&token.source_position, "traditional C rejects the '%Y' suffix",
6040                  token.symbol);
6041 }
6042
6043 static void check_integer_suffix(void)
6044 {
6045         symbol_t *suffix = token.symbol;
6046         if (suffix == NULL)
6047                 return;
6048
6049         bool not_traditional = false;
6050         const char *c = suffix->string;
6051         if (*c == 'l' || *c == 'L') {
6052                 ++c;
6053                 if (*c == *(c-1)) {
6054                         not_traditional = true;
6055                         ++c;
6056                         if (*c == 'u' || *c == 'U') {
6057                                 ++c;
6058                         }
6059                 } else if (*c == 'u' || *c == 'U') {
6060                         not_traditional = true;
6061                         ++c;
6062                 }
6063         } else if (*c == 'u' || *c == 'U') {
6064                 not_traditional = true;
6065                 ++c;
6066                 if (*c == 'l' || *c == 'L') {
6067                         ++c;
6068                         if (*c == *(c-1)) {
6069                                 ++c;
6070                         }
6071                 }
6072         }
6073         if (*c != '\0') {
6074                 errorf(&token.source_position,
6075                        "invalid suffix '%s' on integer constant", suffix->string);
6076         } else if (not_traditional) {
6077                 warn_traditional_suffix();
6078         }
6079 }
6080
6081 static type_t *check_floatingpoint_suffix(void)
6082 {
6083         symbol_t *suffix = token.symbol;
6084         type_t   *type   = type_double;
6085         if (suffix == NULL)
6086                 return type;
6087
6088         bool not_traditional = false;
6089         const char *c = suffix->string;
6090         if (*c == 'f' || *c == 'F') {
6091                 ++c;
6092                 type = type_float;
6093         } else if (*c == 'l' || *c == 'L') {
6094                 ++c;
6095                 type = type_long_double;
6096         }
6097         if (*c != '\0') {
6098                 errorf(&token.source_position,
6099                        "invalid suffix '%s' on floatingpoint constant", suffix->string);
6100         } else if (not_traditional) {
6101                 warn_traditional_suffix();
6102         }
6103
6104         return type;
6105 }
6106
6107 /**
6108  * Parse an integer constant.
6109  */
6110 static expression_t *parse_number_literal(void)
6111 {
6112         expression_kind_t  kind;
6113         type_t            *type;
6114
6115         switch (token.type) {
6116         case T_INTEGER:
6117                 kind = EXPR_LITERAL_INTEGER;
6118                 check_integer_suffix();
6119                 type = type_int;
6120                 break;
6121         case T_INTEGER_OCTAL:
6122                 kind = EXPR_LITERAL_INTEGER_OCTAL;
6123                 check_integer_suffix();
6124                 type = type_int;
6125                 break;
6126         case T_INTEGER_HEXADECIMAL:
6127                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
6128                 check_integer_suffix();
6129                 type = type_int;
6130                 break;
6131         case T_FLOATINGPOINT:
6132                 kind = EXPR_LITERAL_FLOATINGPOINT;
6133                 type = check_floatingpoint_suffix();
6134                 break;
6135         case T_FLOATINGPOINT_HEXADECIMAL:
6136                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
6137                 type = check_floatingpoint_suffix();
6138                 break;
6139         default:
6140                 panic("unexpected token type in parse_number_literal");
6141         }
6142
6143         expression_t *literal = allocate_expression_zero(kind);
6144         literal->base.source_position = token.source_position;
6145         literal->base.type            = type;
6146         literal->literal.value        = token.literal;
6147         literal->literal.suffix       = token.symbol;
6148         next_token();
6149
6150         /* integer type depends on the size of the number and the size
6151          * representable by the types. The backend/codegeneration has to determine
6152          * that
6153          */
6154         determine_literal_type(&literal->literal);
6155         return literal;
6156 }
6157
6158 /**
6159  * Parse a character constant.
6160  */
6161 static expression_t *parse_character_constant(void)
6162 {
6163         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
6164         literal->base.source_position = token.source_position;
6165         literal->base.type            = c_mode & _CXX ? type_char : type_int;
6166         literal->literal.value        = token.literal;
6167
6168         size_t len = literal->literal.value.size;
6169         if (len > 1) {
6170                 if (!GNU_MODE && !(c_mode & _C99)) {
6171                         errorf(HERE, "more than 1 character in character constant");
6172                 } else if (warning.multichar) {
6173                         literal->base.type = type_int;
6174                         warningf(HERE, "multi-character character constant");
6175                 }
6176         }
6177
6178         next_token();
6179         return literal;
6180 }
6181
6182 /**
6183  * Parse a wide character constant.
6184  */
6185 static expression_t *parse_wide_character_constant(void)
6186 {
6187         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6188         literal->base.source_position = token.source_position;
6189         literal->base.type            = type_int;
6190         literal->literal.value        = token.literal;
6191
6192         size_t len = wstrlen(&literal->literal.value);
6193         if (len > 1) {
6194                 warningf(HERE, "multi-character character constant");
6195         }
6196
6197         next_token();
6198         return literal;
6199 }
6200
6201 static entity_t *create_implicit_function(symbol_t *symbol,
6202                 const source_position_t *source_position)
6203 {
6204         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6205         ntype->function.return_type            = type_int;
6206         ntype->function.unspecified_parameters = true;
6207         ntype->function.linkage                = LINKAGE_C;
6208         type_t *type                           = identify_new_type(ntype);
6209
6210         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol);
6211         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6212         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6213         entity->declaration.type                   = type;
6214         entity->declaration.implicit               = true;
6215         entity->base.source_position               = *source_position;
6216
6217         if (current_scope != NULL) {
6218                 bool strict_prototypes_old = warning.strict_prototypes;
6219                 warning.strict_prototypes  = false;
6220                 record_entity(entity, false);
6221                 warning.strict_prototypes = strict_prototypes_old;
6222         }
6223
6224         return entity;
6225 }
6226
6227 /**
6228  * Performs automatic type cast as described in §6.3.2.1.
6229  *
6230  * @param orig_type  the original type
6231  */
6232 static type_t *automatic_type_conversion(type_t *orig_type)
6233 {
6234         type_t *type = skip_typeref(orig_type);
6235         if (is_type_array(type)) {
6236                 array_type_t *array_type   = &type->array;
6237                 type_t       *element_type = array_type->element_type;
6238                 unsigned      qualifiers   = array_type->base.qualifiers;
6239
6240                 return make_pointer_type(element_type, qualifiers);
6241         }
6242
6243         if (is_type_function(type)) {
6244                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6245         }
6246
6247         return orig_type;
6248 }
6249
6250 /**
6251  * reverts the automatic casts of array to pointer types and function
6252  * to function-pointer types as defined §6.3.2.1
6253  */
6254 type_t *revert_automatic_type_conversion(const expression_t *expression)
6255 {
6256         switch (expression->kind) {
6257         case EXPR_REFERENCE: {
6258                 entity_t *entity = expression->reference.entity;
6259                 if (is_declaration(entity)) {
6260                         return entity->declaration.type;
6261                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6262                         return entity->enum_value.enum_type;
6263                 } else {
6264                         panic("no declaration or enum in reference");
6265                 }
6266         }
6267
6268         case EXPR_SELECT: {
6269                 entity_t *entity = expression->select.compound_entry;
6270                 assert(is_declaration(entity));
6271                 type_t   *type   = entity->declaration.type;
6272                 return get_qualified_type(type,
6273                                 expression->base.type->base.qualifiers);
6274         }
6275
6276         case EXPR_UNARY_DEREFERENCE: {
6277                 const expression_t *const value = expression->unary.value;
6278                 type_t             *const type  = skip_typeref(value->base.type);
6279                 if (!is_type_pointer(type))
6280                         return type_error_type;
6281                 return type->pointer.points_to;
6282         }
6283
6284         case EXPR_ARRAY_ACCESS: {
6285                 const expression_t *array_ref = expression->array_access.array_ref;
6286                 type_t             *type_left = skip_typeref(array_ref->base.type);
6287                 if (!is_type_pointer(type_left))
6288                         return type_error_type;
6289                 return type_left->pointer.points_to;
6290         }
6291
6292         case EXPR_STRING_LITERAL: {
6293                 size_t size = expression->string_literal.value.size;
6294                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6295         }
6296
6297         case EXPR_WIDE_STRING_LITERAL: {
6298                 size_t size = wstrlen(&expression->string_literal.value);
6299                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6300         }
6301
6302         case EXPR_COMPOUND_LITERAL:
6303                 return expression->compound_literal.type;
6304
6305         default:
6306                 break;
6307         }
6308         return expression->base.type;
6309 }
6310
6311 /**
6312  * Find an entity matching a symbol in a scope.
6313  * Uses current scope if scope is NULL
6314  */
6315 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6316                                namespace_tag_t namespc)
6317 {
6318         if (scope == NULL) {
6319                 return get_entity(symbol, namespc);
6320         }
6321
6322         /* we should optimize here, if scope grows above a certain size we should
6323            construct a hashmap here... */
6324         entity_t *entity = scope->entities;
6325         for ( ; entity != NULL; entity = entity->base.next) {
6326                 if (entity->base.symbol == symbol && entity->base.namespc == namespc)
6327                         break;
6328         }
6329
6330         return entity;
6331 }
6332
6333 static entity_t *parse_qualified_identifier(void)
6334 {
6335         /* namespace containing the symbol */
6336         symbol_t          *symbol;
6337         source_position_t  pos;
6338         const scope_t     *lookup_scope = NULL;
6339
6340         if (next_if(T_COLONCOLON))
6341                 lookup_scope = &unit->scope;
6342
6343         entity_t *entity;
6344         while (true) {
6345                 if (token.type != T_IDENTIFIER) {
6346                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6347                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6348                 }
6349                 symbol = token.symbol;
6350                 pos    = *HERE;
6351                 next_token();
6352
6353                 /* lookup entity */
6354                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6355
6356                 if (!next_if(T_COLONCOLON))
6357                         break;
6358
6359                 switch (entity->kind) {
6360                 case ENTITY_NAMESPACE:
6361                         lookup_scope = &entity->namespacee.members;
6362                         break;
6363                 case ENTITY_STRUCT:
6364                 case ENTITY_UNION:
6365                 case ENTITY_CLASS:
6366                         lookup_scope = &entity->compound.members;
6367                         break;
6368                 default:
6369                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6370                                symbol, get_entity_kind_name(entity->kind));
6371                         goto end_error;
6372                 }
6373         }
6374
6375         if (entity == NULL) {
6376                 if (!strict_mode && token.type == '(') {
6377                         /* an implicitly declared function */
6378                         if (warning.error_implicit_function_declaration) {
6379                                 errorf(&pos, "implicit declaration of function '%Y'", symbol);
6380                         } else if (warning.implicit_function_declaration) {
6381                                 warningf(&pos, "implicit declaration of function '%Y'", symbol);
6382                         }
6383
6384                         entity = create_implicit_function(symbol, &pos);
6385                 } else {
6386                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6387                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6388                 }
6389         }
6390
6391         return entity;
6392
6393 end_error:
6394         /* skip further qualifications */
6395         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6396
6397         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6398 }
6399
6400 static expression_t *parse_reference(void)
6401 {
6402         source_position_t const pos    = token.source_position;
6403         entity_t         *const entity = parse_qualified_identifier();
6404
6405         type_t *orig_type;
6406         if (is_declaration(entity)) {
6407                 orig_type = entity->declaration.type;
6408         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6409                 orig_type = entity->enum_value.enum_type;
6410         } else {
6411                 panic("expected declaration or enum value in reference");
6412         }
6413
6414         /* we always do the auto-type conversions; the & and sizeof parser contains
6415          * code to revert this! */
6416         type_t *type = automatic_type_conversion(orig_type);
6417
6418         expression_kind_t kind = EXPR_REFERENCE;
6419         if (entity->kind == ENTITY_ENUM_VALUE)
6420                 kind = EXPR_REFERENCE_ENUM_VALUE;
6421
6422         expression_t *expression         = allocate_expression_zero(kind);
6423         expression->base.source_position = pos;
6424         expression->base.type            = type;
6425         expression->reference.entity     = entity;
6426
6427         /* this declaration is used */
6428         if (is_declaration(entity)) {
6429                 entity->declaration.used = true;
6430         }
6431
6432         if (entity->base.parent_scope != file_scope
6433                 && (current_function != NULL
6434                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6435                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6436                 if (entity->kind == ENTITY_VARIABLE) {
6437                         /* access of a variable from an outer function */
6438                         entity->variable.address_taken = true;
6439                 } else if (entity->kind == ENTITY_PARAMETER) {
6440                         entity->parameter.address_taken = true;
6441                 }
6442                 current_function->need_closure = true;
6443         }
6444
6445         check_deprecated(HERE, entity);
6446
6447         if (warning.init_self && entity == current_init_decl && !in_type_prop
6448             && entity->kind == ENTITY_VARIABLE) {
6449                 current_init_decl = NULL;
6450                 warningf(&pos, "variable '%#T' is initialized by itself",
6451                          entity->declaration.type, entity->base.symbol);
6452         }
6453
6454         return expression;
6455 }
6456
6457 static bool semantic_cast(expression_t *cast)
6458 {
6459         expression_t            *expression      = cast->unary.value;
6460         type_t                  *orig_dest_type  = cast->base.type;
6461         type_t                  *orig_type_right = expression->base.type;
6462         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6463         type_t            const *src_type        = skip_typeref(orig_type_right);
6464         source_position_t const *pos             = &cast->base.source_position;
6465
6466         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6467         if (dst_type == type_void)
6468                 return true;
6469
6470         /* only integer and pointer can be casted to pointer */
6471         if (is_type_pointer(dst_type)  &&
6472             !is_type_pointer(src_type) &&
6473             !is_type_integer(src_type) &&
6474             is_type_valid(src_type)) {
6475                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6476                 return false;
6477         }
6478
6479         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6480                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6481                 return false;
6482         }
6483
6484         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6485                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6486                 return false;
6487         }
6488
6489         if (warning.cast_qual &&
6490             is_type_pointer(src_type) &&
6491             is_type_pointer(dst_type)) {
6492                 type_t *src = skip_typeref(src_type->pointer.points_to);
6493                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6494                 unsigned missing_qualifiers =
6495                         src->base.qualifiers & ~dst->base.qualifiers;
6496                 if (missing_qualifiers != 0) {
6497                         warningf(pos,
6498                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6499                                  missing_qualifiers, orig_type_right);
6500                 }
6501         }
6502         return true;
6503 }
6504
6505 static expression_t *parse_compound_literal(type_t *type)
6506 {
6507         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6508
6509         parse_initializer_env_t env;
6510         env.type             = type;
6511         env.entity           = NULL;
6512         env.must_be_constant = false;
6513         initializer_t *initializer = parse_initializer(&env);
6514         type = env.type;
6515
6516         expression->compound_literal.initializer = initializer;
6517         expression->compound_literal.type        = type;
6518         expression->base.type                    = automatic_type_conversion(type);
6519
6520         return expression;
6521 }
6522
6523 /**
6524  * Parse a cast expression.
6525  */
6526 static expression_t *parse_cast(void)
6527 {
6528         source_position_t source_position = token.source_position;
6529
6530         eat('(');
6531         add_anchor_token(')');
6532
6533         type_t *type = parse_typename();
6534
6535         rem_anchor_token(')');
6536         expect(')', end_error);
6537
6538         if (token.type == '{') {
6539                 return parse_compound_literal(type);
6540         }
6541
6542         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6543         cast->base.source_position = source_position;
6544
6545         expression_t *value = parse_subexpression(PREC_CAST);
6546         cast->base.type   = type;
6547         cast->unary.value = value;
6548
6549         if (! semantic_cast(cast)) {
6550                 /* TODO: record the error in the AST. else it is impossible to detect it */
6551         }
6552
6553         return cast;
6554 end_error:
6555         return create_invalid_expression();
6556 }
6557
6558 /**
6559  * Parse a statement expression.
6560  */
6561 static expression_t *parse_statement_expression(void)
6562 {
6563         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6564
6565         eat('(');
6566         add_anchor_token(')');
6567
6568         statement_t *statement          = parse_compound_statement(true);
6569         statement->compound.stmt_expr   = true;
6570         expression->statement.statement = statement;
6571
6572         /* find last statement and use its type */
6573         type_t *type = type_void;
6574         const statement_t *stmt = statement->compound.statements;
6575         if (stmt != NULL) {
6576                 while (stmt->base.next != NULL)
6577                         stmt = stmt->base.next;
6578
6579                 if (stmt->kind == STATEMENT_EXPRESSION) {
6580                         type = stmt->expression.expression->base.type;
6581                 }
6582         } else if (warning.other) {
6583                 warningf(&expression->base.source_position, "empty statement expression ({})");
6584         }
6585         expression->base.type = type;
6586
6587         rem_anchor_token(')');
6588         expect(')', end_error);
6589
6590 end_error:
6591         return expression;
6592 }
6593
6594 /**
6595  * Parse a parenthesized expression.
6596  */
6597 static expression_t *parse_parenthesized_expression(void)
6598 {
6599         token_t const* const la1 = look_ahead(1);
6600         switch (la1->type) {
6601         case '{':
6602                 /* gcc extension: a statement expression */
6603                 return parse_statement_expression();
6604
6605         case T_IDENTIFIER:
6606                 if (is_typedef_symbol(la1->symbol)) {
6607         TYPE_QUALIFIERS
6608         TYPE_SPECIFIERS
6609                         return parse_cast();
6610                 }
6611         }
6612
6613         eat('(');
6614         add_anchor_token(')');
6615         expression_t *result = parse_expression();
6616         result->base.parenthesized = true;
6617         rem_anchor_token(')');
6618         expect(')', end_error);
6619
6620 end_error:
6621         return result;
6622 }
6623
6624 static expression_t *parse_function_keyword(void)
6625 {
6626         /* TODO */
6627
6628         if (current_function == NULL) {
6629                 errorf(HERE, "'__func__' used outside of a function");
6630         }
6631
6632         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6633         expression->base.type     = type_char_ptr;
6634         expression->funcname.kind = FUNCNAME_FUNCTION;
6635
6636         next_token();
6637
6638         return expression;
6639 }
6640
6641 static expression_t *parse_pretty_function_keyword(void)
6642 {
6643         if (current_function == NULL) {
6644                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6645         }
6646
6647         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6648         expression->base.type     = type_char_ptr;
6649         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6650
6651         eat(T___PRETTY_FUNCTION__);
6652
6653         return expression;
6654 }
6655
6656 static expression_t *parse_funcsig_keyword(void)
6657 {
6658         if (current_function == NULL) {
6659                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6660         }
6661
6662         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6663         expression->base.type     = type_char_ptr;
6664         expression->funcname.kind = FUNCNAME_FUNCSIG;
6665
6666         eat(T___FUNCSIG__);
6667
6668         return expression;
6669 }
6670
6671 static expression_t *parse_funcdname_keyword(void)
6672 {
6673         if (current_function == NULL) {
6674                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6675         }
6676
6677         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6678         expression->base.type     = type_char_ptr;
6679         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6680
6681         eat(T___FUNCDNAME__);
6682
6683         return expression;
6684 }
6685
6686 static designator_t *parse_designator(void)
6687 {
6688         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6689         result->source_position = *HERE;
6690
6691         if (token.type != T_IDENTIFIER) {
6692                 parse_error_expected("while parsing member designator",
6693                                      T_IDENTIFIER, NULL);
6694                 return NULL;
6695         }
6696         result->symbol = token.symbol;
6697         next_token();
6698
6699         designator_t *last_designator = result;
6700         while (true) {
6701                 if (next_if('.')) {
6702                         if (token.type != T_IDENTIFIER) {
6703                                 parse_error_expected("while parsing member designator",
6704                                                      T_IDENTIFIER, NULL);
6705                                 return NULL;
6706                         }
6707                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6708                         designator->source_position = *HERE;
6709                         designator->symbol          = token.symbol;
6710                         next_token();
6711
6712                         last_designator->next = designator;
6713                         last_designator       = designator;
6714                         continue;
6715                 }
6716                 if (next_if('[')) {
6717                         add_anchor_token(']');
6718                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6719                         designator->source_position = *HERE;
6720                         designator->array_index     = parse_expression();
6721                         rem_anchor_token(']');
6722                         expect(']', end_error);
6723                         if (designator->array_index == NULL) {
6724                                 return NULL;
6725                         }
6726
6727                         last_designator->next = designator;
6728                         last_designator       = designator;
6729                         continue;
6730                 }
6731                 break;
6732         }
6733
6734         return result;
6735 end_error:
6736         return NULL;
6737 }
6738
6739 /**
6740  * Parse the __builtin_offsetof() expression.
6741  */
6742 static expression_t *parse_offsetof(void)
6743 {
6744         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6745         expression->base.type    = type_size_t;
6746
6747         eat(T___builtin_offsetof);
6748
6749         expect('(', end_error);
6750         add_anchor_token(',');
6751         type_t *type = parse_typename();
6752         rem_anchor_token(',');
6753         expect(',', end_error);
6754         add_anchor_token(')');
6755         designator_t *designator = parse_designator();
6756         rem_anchor_token(')');
6757         expect(')', end_error);
6758
6759         expression->offsetofe.type       = type;
6760         expression->offsetofe.designator = designator;
6761
6762         type_path_t path;
6763         memset(&path, 0, sizeof(path));
6764         path.top_type = type;
6765         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6766
6767         descend_into_subtype(&path);
6768
6769         if (!walk_designator(&path, designator, true)) {
6770                 return create_invalid_expression();
6771         }
6772
6773         DEL_ARR_F(path.path);
6774
6775         return expression;
6776 end_error:
6777         return create_invalid_expression();
6778 }
6779
6780 /**
6781  * Parses a _builtin_va_start() expression.
6782  */
6783 static expression_t *parse_va_start(void)
6784 {
6785         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6786
6787         eat(T___builtin_va_start);
6788
6789         expect('(', end_error);
6790         add_anchor_token(',');
6791         expression->va_starte.ap = parse_assignment_expression();
6792         rem_anchor_token(',');
6793         expect(',', end_error);
6794         expression_t *const expr = parse_assignment_expression();
6795         if (expr->kind == EXPR_REFERENCE) {
6796                 entity_t *const entity = expr->reference.entity;
6797                 if (!current_function->base.type->function.variadic) {
6798                         errorf(&expr->base.source_position,
6799                                         "'va_start' used in non-variadic function");
6800                 } else if (entity->base.parent_scope != &current_function->parameters ||
6801                                 entity->base.next != NULL ||
6802                                 entity->kind != ENTITY_PARAMETER) {
6803                         errorf(&expr->base.source_position,
6804                                "second argument of 'va_start' must be last parameter of the current function");
6805                 } else {
6806                         expression->va_starte.parameter = &entity->variable;
6807                 }
6808                 expect(')', end_error);
6809                 return expression;
6810         }
6811         expect(')', end_error);
6812 end_error:
6813         return create_invalid_expression();
6814 }
6815
6816 /**
6817  * Parses a __builtin_va_arg() expression.
6818  */
6819 static expression_t *parse_va_arg(void)
6820 {
6821         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6822
6823         eat(T___builtin_va_arg);
6824
6825         expect('(', end_error);
6826         call_argument_t ap;
6827         ap.expression = parse_assignment_expression();
6828         expression->va_arge.ap = ap.expression;
6829         check_call_argument(type_valist, &ap, 1);
6830
6831         expect(',', end_error);
6832         expression->base.type = parse_typename();
6833         expect(')', end_error);
6834
6835         return expression;
6836 end_error:
6837         return create_invalid_expression();
6838 }
6839
6840 /**
6841  * Parses a __builtin_va_copy() expression.
6842  */
6843 static expression_t *parse_va_copy(void)
6844 {
6845         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6846
6847         eat(T___builtin_va_copy);
6848
6849         expect('(', end_error);
6850         expression_t *dst = parse_assignment_expression();
6851         assign_error_t error = semantic_assign(type_valist, dst);
6852         report_assign_error(error, type_valist, dst, "call argument 1",
6853                             &dst->base.source_position);
6854         expression->va_copye.dst = dst;
6855
6856         expect(',', end_error);
6857
6858         call_argument_t src;
6859         src.expression = parse_assignment_expression();
6860         check_call_argument(type_valist, &src, 2);
6861         expression->va_copye.src = src.expression;
6862         expect(')', end_error);
6863
6864         return expression;
6865 end_error:
6866         return create_invalid_expression();
6867 }
6868
6869 /**
6870  * Parses a __builtin_constant_p() expression.
6871  */
6872 static expression_t *parse_builtin_constant(void)
6873 {
6874         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6875
6876         eat(T___builtin_constant_p);
6877
6878         expect('(', end_error);
6879         add_anchor_token(')');
6880         expression->builtin_constant.value = parse_assignment_expression();
6881         rem_anchor_token(')');
6882         expect(')', end_error);
6883         expression->base.type = type_int;
6884
6885         return expression;
6886 end_error:
6887         return create_invalid_expression();
6888 }
6889
6890 /**
6891  * Parses a __builtin_types_compatible_p() expression.
6892  */
6893 static expression_t *parse_builtin_types_compatible(void)
6894 {
6895         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6896
6897         eat(T___builtin_types_compatible_p);
6898
6899         expect('(', end_error);
6900         add_anchor_token(')');
6901         add_anchor_token(',');
6902         expression->builtin_types_compatible.left = parse_typename();
6903         rem_anchor_token(',');
6904         expect(',', end_error);
6905         expression->builtin_types_compatible.right = parse_typename();
6906         rem_anchor_token(')');
6907         expect(')', end_error);
6908         expression->base.type = type_int;
6909
6910         return expression;
6911 end_error:
6912         return create_invalid_expression();
6913 }
6914
6915 /**
6916  * Parses a __builtin_is_*() compare expression.
6917  */
6918 static expression_t *parse_compare_builtin(void)
6919 {
6920         expression_t *expression;
6921
6922         switch (token.type) {
6923         case T___builtin_isgreater:
6924                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6925                 break;
6926         case T___builtin_isgreaterequal:
6927                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6928                 break;
6929         case T___builtin_isless:
6930                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6931                 break;
6932         case T___builtin_islessequal:
6933                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6934                 break;
6935         case T___builtin_islessgreater:
6936                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6937                 break;
6938         case T___builtin_isunordered:
6939                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6940                 break;
6941         default:
6942                 internal_errorf(HERE, "invalid compare builtin found");
6943         }
6944         expression->base.source_position = *HERE;
6945         next_token();
6946
6947         expect('(', end_error);
6948         expression->binary.left = parse_assignment_expression();
6949         expect(',', end_error);
6950         expression->binary.right = parse_assignment_expression();
6951         expect(')', end_error);
6952
6953         type_t *const orig_type_left  = expression->binary.left->base.type;
6954         type_t *const orig_type_right = expression->binary.right->base.type;
6955
6956         type_t *const type_left  = skip_typeref(orig_type_left);
6957         type_t *const type_right = skip_typeref(orig_type_right);
6958         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6959                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6960                         type_error_incompatible("invalid operands in comparison",
6961                                 &expression->base.source_position, orig_type_left, orig_type_right);
6962                 }
6963         } else {
6964                 semantic_comparison(&expression->binary);
6965         }
6966
6967         return expression;
6968 end_error:
6969         return create_invalid_expression();
6970 }
6971
6972 /**
6973  * Parses a MS assume() expression.
6974  */
6975 static expression_t *parse_assume(void)
6976 {
6977         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6978
6979         eat(T__assume);
6980
6981         expect('(', end_error);
6982         add_anchor_token(')');
6983         expression->unary.value = parse_assignment_expression();
6984         rem_anchor_token(')');
6985         expect(')', end_error);
6986
6987         expression->base.type = type_void;
6988         return expression;
6989 end_error:
6990         return create_invalid_expression();
6991 }
6992
6993 /**
6994  * Return the label for the current symbol or create a new one.
6995  */
6996 static label_t *get_label(void)
6997 {
6998         assert(token.type == T_IDENTIFIER);
6999         assert(current_function != NULL);
7000
7001         entity_t *label = get_entity(token.symbol, NAMESPACE_LABEL);
7002         /* If we find a local label, we already created the declaration. */
7003         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7004                 if (label->base.parent_scope != current_scope) {
7005                         assert(label->base.parent_scope->depth < current_scope->depth);
7006                         current_function->goto_to_outer = true;
7007                 }
7008         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
7009                 /* There is no matching label in the same function, so create a new one. */
7010                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.symbol);
7011                 label_push(label);
7012         }
7013
7014         eat(T_IDENTIFIER);
7015         return &label->label;
7016 }
7017
7018 /**
7019  * Parses a GNU && label address expression.
7020  */
7021 static expression_t *parse_label_address(void)
7022 {
7023         source_position_t source_position = token.source_position;
7024         eat(T_ANDAND);
7025         if (token.type != T_IDENTIFIER) {
7026                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7027                 goto end_error;
7028         }
7029
7030         label_t *const label = get_label();
7031         label->used          = true;
7032         label->address_taken = true;
7033
7034         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7035         expression->base.source_position = source_position;
7036
7037         /* label address is threaten as a void pointer */
7038         expression->base.type           = type_void_ptr;
7039         expression->label_address.label = label;
7040         return expression;
7041 end_error:
7042         return create_invalid_expression();
7043 }
7044
7045 /**
7046  * Parse a microsoft __noop expression.
7047  */
7048 static expression_t *parse_noop_expression(void)
7049 {
7050         /* the result is a (int)0 */
7051         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
7052         literal->base.type            = type_int;
7053         literal->base.source_position = token.source_position;
7054         literal->literal.value.begin  = "__noop";
7055         literal->literal.value.size   = 6;
7056
7057         eat(T___noop);
7058
7059         if (token.type == '(') {
7060                 /* parse arguments */
7061                 eat('(');
7062                 add_anchor_token(')');
7063                 add_anchor_token(',');
7064
7065                 if (token.type != ')') do {
7066                         (void)parse_assignment_expression();
7067                 } while (next_if(','));
7068         }
7069         rem_anchor_token(',');
7070         rem_anchor_token(')');
7071         expect(')', end_error);
7072
7073 end_error:
7074         return literal;
7075 }
7076
7077 /**
7078  * Parses a primary expression.
7079  */
7080 static expression_t *parse_primary_expression(void)
7081 {
7082         switch (token.type) {
7083         case T_false:                        return parse_boolean_literal(false);
7084         case T_true:                         return parse_boolean_literal(true);
7085         case T_INTEGER:
7086         case T_INTEGER_OCTAL:
7087         case T_INTEGER_HEXADECIMAL:
7088         case T_FLOATINGPOINT:
7089         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
7090         case T_CHARACTER_CONSTANT:           return parse_character_constant();
7091         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7092         case T_STRING_LITERAL:
7093         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
7094         case T___FUNCTION__:
7095         case T___func__:                     return parse_function_keyword();
7096         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7097         case T___FUNCSIG__:                  return parse_funcsig_keyword();
7098         case T___FUNCDNAME__:                return parse_funcdname_keyword();
7099         case T___builtin_offsetof:           return parse_offsetof();
7100         case T___builtin_va_start:           return parse_va_start();
7101         case T___builtin_va_arg:             return parse_va_arg();
7102         case T___builtin_va_copy:            return parse_va_copy();
7103         case T___builtin_isgreater:
7104         case T___builtin_isgreaterequal:
7105         case T___builtin_isless:
7106         case T___builtin_islessequal:
7107         case T___builtin_islessgreater:
7108         case T___builtin_isunordered:        return parse_compare_builtin();
7109         case T___builtin_constant_p:         return parse_builtin_constant();
7110         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7111         case T__assume:                      return parse_assume();
7112         case T_ANDAND:
7113                 if (GNU_MODE)
7114                         return parse_label_address();
7115                 break;
7116
7117         case '(':                            return parse_parenthesized_expression();
7118         case T___noop:                       return parse_noop_expression();
7119
7120         /* Gracefully handle type names while parsing expressions. */
7121         case T_COLONCOLON:
7122                 return parse_reference();
7123         case T_IDENTIFIER:
7124                 if (!is_typedef_symbol(token.symbol)) {
7125                         return parse_reference();
7126                 }
7127                 /* FALLTHROUGH */
7128         TYPENAME_START {
7129                 source_position_t  const pos  = *HERE;
7130                 type_t const      *const type = parse_typename();
7131                 errorf(&pos, "encountered type '%T' while parsing expression", type);
7132                 return create_invalid_expression();
7133         }
7134         }
7135
7136         errorf(HERE, "unexpected token %K, expected an expression", &token);
7137         eat_until_anchor();
7138         return create_invalid_expression();
7139 }
7140
7141 static expression_t *parse_array_expression(expression_t *left)
7142 {
7143         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7144         array_access_expression_t *const arr  = &expr->array_access;
7145
7146         eat('[');
7147         add_anchor_token(']');
7148
7149         expression_t *const inside = parse_expression();
7150
7151         type_t *const orig_type_left   = left->base.type;
7152         type_t *const orig_type_inside = inside->base.type;
7153
7154         type_t *const type_left   = skip_typeref(orig_type_left);
7155         type_t *const type_inside = skip_typeref(orig_type_inside);
7156
7157         expression_t *ref;
7158         expression_t *idx;
7159         type_t       *idx_type;
7160         type_t       *res_type;
7161         if (is_type_pointer(type_left)) {
7162                 ref      = left;
7163                 idx      = inside;
7164                 idx_type = type_inside;
7165                 res_type = type_left->pointer.points_to;
7166                 goto check_idx;
7167         } else if (is_type_pointer(type_inside)) {
7168                 arr->flipped = true;
7169                 ref      = inside;
7170                 idx      = left;
7171                 idx_type = type_left;
7172                 res_type = type_inside->pointer.points_to;
7173 check_idx:
7174                 res_type = automatic_type_conversion(res_type);
7175                 if (!is_type_integer(idx_type)) {
7176                         errorf(&idx->base.source_position, "array subscript must have integer type");
7177                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR) && warning.char_subscripts) {
7178                         warningf(&idx->base.source_position, "array subscript has char type");
7179                 }
7180         } else {
7181                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7182                         errorf(HERE,
7183                                 "array access on object with non-pointer types '%T', '%T'",
7184                                 orig_type_left, orig_type_inside);
7185                 }
7186                 res_type = type_error_type;
7187                 ref      = left;
7188                 idx      = inside;
7189         }
7190
7191         arr->array_ref = ref;
7192         arr->index     = idx;
7193         arr->base.type = res_type;
7194
7195         rem_anchor_token(']');
7196         expect(']', end_error);
7197 end_error:
7198         return expr;
7199 }
7200
7201 static expression_t *parse_typeprop(expression_kind_t const kind)
7202 {
7203         expression_t  *tp_expression = allocate_expression_zero(kind);
7204         tp_expression->base.type     = type_size_t;
7205
7206         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7207
7208         /* we only refer to a type property, mark this case */
7209         bool old     = in_type_prop;
7210         in_type_prop = true;
7211
7212         type_t       *orig_type;
7213         expression_t *expression;
7214         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7215                 next_token();
7216                 add_anchor_token(')');
7217                 orig_type = parse_typename();
7218                 rem_anchor_token(')');
7219                 expect(')', end_error);
7220
7221                 if (token.type == '{') {
7222                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7223                          * starting with a compound literal */
7224                         expression = parse_compound_literal(orig_type);
7225                         goto typeprop_expression;
7226                 }
7227         } else {
7228                 expression = parse_subexpression(PREC_UNARY);
7229
7230 typeprop_expression:
7231                 tp_expression->typeprop.tp_expression = expression;
7232
7233                 orig_type = revert_automatic_type_conversion(expression);
7234                 expression->base.type = orig_type;
7235         }
7236
7237         tp_expression->typeprop.type   = orig_type;
7238         type_t const* const type       = skip_typeref(orig_type);
7239         char   const*       wrong_type = NULL;
7240         if (is_type_incomplete(type)) {
7241                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7242                         wrong_type = "incomplete";
7243         } else if (type->kind == TYPE_FUNCTION) {
7244                 if (GNU_MODE) {
7245                         /* function types are allowed (and return 1) */
7246                         if (warning.other) {
7247                                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7248                                 warningf(&tp_expression->base.source_position,
7249                                          "%s expression with function argument returns invalid result", what);
7250                         }
7251                 } else {
7252                         wrong_type = "function";
7253                 }
7254         } else {
7255                 if (is_type_incomplete(type))
7256                         wrong_type = "incomplete";
7257         }
7258         if (type->kind == TYPE_BITFIELD)
7259                 wrong_type = "bitfield";
7260
7261         if (wrong_type != NULL) {
7262                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7263                 errorf(&tp_expression->base.source_position,
7264                                 "operand of %s expression must not be of %s type '%T'",
7265                                 what, wrong_type, orig_type);
7266         }
7267
7268 end_error:
7269         in_type_prop = old;
7270         return tp_expression;
7271 }
7272
7273 static expression_t *parse_sizeof(void)
7274 {
7275         return parse_typeprop(EXPR_SIZEOF);
7276 }
7277
7278 static expression_t *parse_alignof(void)
7279 {
7280         return parse_typeprop(EXPR_ALIGNOF);
7281 }
7282
7283 static expression_t *parse_select_expression(expression_t *addr)
7284 {
7285         assert(token.type == '.' || token.type == T_MINUSGREATER);
7286         bool select_left_arrow = (token.type == T_MINUSGREATER);
7287         source_position_t const pos = *HERE;
7288         next_token();
7289
7290         if (token.type != T_IDENTIFIER) {
7291                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7292                 return create_invalid_expression();
7293         }
7294         symbol_t *symbol = token.symbol;
7295         next_token();
7296
7297         type_t *const orig_type = addr->base.type;
7298         type_t *const type      = skip_typeref(orig_type);
7299
7300         type_t *type_left;
7301         bool    saw_error = false;
7302         if (is_type_pointer(type)) {
7303                 if (!select_left_arrow) {
7304                         errorf(&pos,
7305                                "request for member '%Y' in something not a struct or union, but '%T'",
7306                                symbol, orig_type);
7307                         saw_error = true;
7308                 }
7309                 type_left = skip_typeref(type->pointer.points_to);
7310         } else {
7311                 if (select_left_arrow && is_type_valid(type)) {
7312                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7313                         saw_error = true;
7314                 }
7315                 type_left = type;
7316         }
7317
7318         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7319             type_left->kind != TYPE_COMPOUND_UNION) {
7320
7321                 if (is_type_valid(type_left) && !saw_error) {
7322                         errorf(&pos,
7323                                "request for member '%Y' in something not a struct or union, but '%T'",
7324                                symbol, type_left);
7325                 }
7326                 return create_invalid_expression();
7327         }
7328
7329         compound_t *compound = type_left->compound.compound;
7330         if (!compound->complete) {
7331                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7332                        symbol, type_left);
7333                 return create_invalid_expression();
7334         }
7335
7336         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7337         expression_t      *result     =
7338                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7339
7340         if (result == NULL) {
7341                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7342                 return create_invalid_expression();
7343         }
7344
7345         return result;
7346 }
7347
7348 static void check_call_argument(type_t          *expected_type,
7349                                 call_argument_t *argument, unsigned pos)
7350 {
7351         type_t         *expected_type_skip = skip_typeref(expected_type);
7352         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7353         expression_t   *arg_expr           = argument->expression;
7354         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7355
7356         /* handle transparent union gnu extension */
7357         if (is_type_union(expected_type_skip)
7358                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7359                 compound_t *union_decl  = expected_type_skip->compound.compound;
7360                 type_t     *best_type   = NULL;
7361                 entity_t   *entry       = union_decl->members.entities;
7362                 for ( ; entry != NULL; entry = entry->base.next) {
7363                         assert(is_declaration(entry));
7364                         type_t *decl_type = entry->declaration.type;
7365                         error = semantic_assign(decl_type, arg_expr);
7366                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7367                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7368                                 continue;
7369
7370                         if (error == ASSIGN_SUCCESS) {
7371                                 best_type = decl_type;
7372                         } else if (best_type == NULL) {
7373                                 best_type = decl_type;
7374                         }
7375                 }
7376
7377                 if (best_type != NULL) {
7378                         expected_type = best_type;
7379                 }
7380         }
7381
7382         error                = semantic_assign(expected_type, arg_expr);
7383         argument->expression = create_implicit_cast(arg_expr, expected_type);
7384
7385         if (error != ASSIGN_SUCCESS) {
7386                 /* report exact scope in error messages (like "in argument 3") */
7387                 char buf[64];
7388                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7389                 report_assign_error(error, expected_type, arg_expr, buf,
7390                                     &arg_expr->base.source_position);
7391         } else if (warning.traditional || warning.conversion) {
7392                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7393                 if (!types_compatible(expected_type_skip, promoted_type) &&
7394                     !types_compatible(expected_type_skip, type_void_ptr) &&
7395                     !types_compatible(type_void_ptr,      promoted_type)) {
7396                         /* Deliberately show the skipped types in this warning */
7397                         warningf(&arg_expr->base.source_position,
7398                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7399                                 pos, expected_type_skip, promoted_type);
7400                 }
7401         }
7402 }
7403
7404 /**
7405  * Handle the semantic restrictions of builtin calls
7406  */
7407 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7408         switch (call->function->reference.entity->function.btk) {
7409                 case bk_gnu_builtin_return_address:
7410                 case bk_gnu_builtin_frame_address: {
7411                         /* argument must be constant */
7412                         call_argument_t *argument = call->arguments;
7413
7414                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7415                                 errorf(&call->base.source_position,
7416                                        "argument of '%Y' must be a constant expression",
7417                                        call->function->reference.entity->base.symbol);
7418                         }
7419                         break;
7420                 }
7421                 case bk_gnu_builtin_object_size:
7422                         if (call->arguments == NULL)
7423                                 break;
7424
7425                         call_argument_t *arg = call->arguments->next;
7426                         if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7427                                 errorf(&call->base.source_position,
7428                                            "second argument of '%Y' must be a constant expression",
7429                                            call->function->reference.entity->base.symbol);
7430                         }
7431                         break;
7432                 case bk_gnu_builtin_prefetch:
7433                         /* second and third argument must be constant if existent */
7434                         if (call->arguments == NULL)
7435                                 break;
7436                         call_argument_t *rw = call->arguments->next;
7437                         call_argument_t *locality = NULL;
7438
7439                         if (rw != NULL) {
7440                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7441                                         errorf(&call->base.source_position,
7442                                                "second argument of '%Y' must be a constant expression",
7443                                                call->function->reference.entity->base.symbol);
7444                                 }
7445                                 locality = rw->next;
7446                         }
7447                         if (locality != NULL) {
7448                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7449                                         errorf(&call->base.source_position,
7450                                                "third argument of '%Y' must be a constant expression",
7451                                                call->function->reference.entity->base.symbol);
7452                                 }
7453                                 locality = rw->next;
7454                         }
7455                         break;
7456                 default:
7457                         break;
7458         }
7459 }
7460
7461 /**
7462  * Parse a call expression, ie. expression '( ... )'.
7463  *
7464  * @param expression  the function address
7465  */
7466 static expression_t *parse_call_expression(expression_t *expression)
7467 {
7468         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7469         call_expression_t *call   = &result->call;
7470         call->function            = expression;
7471
7472         type_t *const orig_type = expression->base.type;
7473         type_t *const type      = skip_typeref(orig_type);
7474
7475         function_type_t *function_type = NULL;
7476         if (is_type_pointer(type)) {
7477                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7478
7479                 if (is_type_function(to_type)) {
7480                         function_type   = &to_type->function;
7481                         call->base.type = function_type->return_type;
7482                 }
7483         }
7484
7485         if (function_type == NULL && is_type_valid(type)) {
7486                 errorf(HERE,
7487                        "called object '%E' (type '%T') is not a pointer to a function",
7488                        expression, orig_type);
7489         }
7490
7491         /* parse arguments */
7492         eat('(');
7493         add_anchor_token(')');
7494         add_anchor_token(',');
7495
7496         if (token.type != ')') {
7497                 call_argument_t **anchor = &call->arguments;
7498                 do {
7499                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7500                         argument->expression = parse_assignment_expression();
7501
7502                         *anchor = argument;
7503                         anchor  = &argument->next;
7504                 } while (next_if(','));
7505         }
7506         rem_anchor_token(',');
7507         rem_anchor_token(')');
7508         expect(')', end_error);
7509
7510         if (function_type == NULL)
7511                 return result;
7512
7513         /* check type and count of call arguments */
7514         function_parameter_t *parameter = function_type->parameters;
7515         call_argument_t      *argument  = call->arguments;
7516         if (!function_type->unspecified_parameters) {
7517                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7518                                 parameter = parameter->next, argument = argument->next) {
7519                         check_call_argument(parameter->type, argument, ++pos);
7520                 }
7521
7522                 if (parameter != NULL) {
7523                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7524                 } else if (argument != NULL && !function_type->variadic) {
7525                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7526                 }
7527         }
7528
7529         /* do default promotion for other arguments */
7530         for (; argument != NULL; argument = argument->next) {
7531                 type_t *type = argument->expression->base.type;
7532                 if (!is_type_object(skip_typeref(type))) {
7533                         errorf(&argument->expression->base.source_position,
7534                                "call argument '%E' must not be void", argument->expression);
7535                 }
7536
7537                 type = get_default_promoted_type(type);
7538
7539                 argument->expression
7540                         = create_implicit_cast(argument->expression, type);
7541         }
7542
7543         check_format(call);
7544
7545         if (warning.aggregate_return &&
7546             is_type_compound(skip_typeref(function_type->return_type))) {
7547                 warningf(&expression->base.source_position,
7548                          "function call has aggregate value");
7549         }
7550
7551         if (expression->kind == EXPR_REFERENCE) {
7552                 reference_expression_t *reference = &expression->reference;
7553                 if (reference->entity->kind == ENTITY_FUNCTION &&
7554                     reference->entity->function.btk != bk_none)
7555                         handle_builtin_argument_restrictions(call);
7556         }
7557
7558 end_error:
7559         return result;
7560 }
7561
7562 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7563
7564 static bool same_compound_type(const type_t *type1, const type_t *type2)
7565 {
7566         return
7567                 is_type_compound(type1) &&
7568                 type1->kind == type2->kind &&
7569                 type1->compound.compound == type2->compound.compound;
7570 }
7571
7572 static expression_t const *get_reference_address(expression_t const *expr)
7573 {
7574         bool regular_take_address = true;
7575         for (;;) {
7576                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7577                         expr = expr->unary.value;
7578                 } else {
7579                         regular_take_address = false;
7580                 }
7581
7582                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7583                         break;
7584
7585                 expr = expr->unary.value;
7586         }
7587
7588         if (expr->kind != EXPR_REFERENCE)
7589                 return NULL;
7590
7591         /* special case for functions which are automatically converted to a
7592          * pointer to function without an extra TAKE_ADDRESS operation */
7593         if (!regular_take_address &&
7594                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7595                 return NULL;
7596         }
7597
7598         return expr;
7599 }
7600
7601 static void warn_reference_address_as_bool(expression_t const* expr)
7602 {
7603         if (!warning.address)
7604                 return;
7605
7606         expr = get_reference_address(expr);
7607         if (expr != NULL) {
7608                 warningf(&expr->base.source_position,
7609                          "the address of '%Y' will always evaluate as 'true'",
7610                          expr->reference.entity->base.symbol);
7611         }
7612 }
7613
7614 static void warn_assignment_in_condition(const expression_t *const expr)
7615 {
7616         if (!warning.parentheses)
7617                 return;
7618         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7619                 return;
7620         if (expr->base.parenthesized)
7621                 return;
7622         warningf(&expr->base.source_position,
7623                         "suggest parentheses around assignment used as truth value");
7624 }
7625
7626 static void semantic_condition(expression_t const *const expr,
7627                                char const *const context)
7628 {
7629         type_t *const type = skip_typeref(expr->base.type);
7630         if (is_type_scalar(type)) {
7631                 warn_reference_address_as_bool(expr);
7632                 warn_assignment_in_condition(expr);
7633         } else if (is_type_valid(type)) {
7634                 errorf(&expr->base.source_position,
7635                                 "%s must have scalar type", context);
7636         }
7637 }
7638
7639 /**
7640  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7641  *
7642  * @param expression  the conditional expression
7643  */
7644 static expression_t *parse_conditional_expression(expression_t *expression)
7645 {
7646         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7647
7648         conditional_expression_t *conditional = &result->conditional;
7649         conditional->condition                = expression;
7650
7651         eat('?');
7652         add_anchor_token(':');
7653
7654         /* §6.5.15:2  The first operand shall have scalar type. */
7655         semantic_condition(expression, "condition of conditional operator");
7656
7657         expression_t *true_expression = expression;
7658         bool          gnu_cond = false;
7659         if (GNU_MODE && token.type == ':') {
7660                 gnu_cond = true;
7661         } else {
7662                 true_expression = parse_expression();
7663         }
7664         rem_anchor_token(':');
7665         expect(':', end_error);
7666 end_error:;
7667         expression_t *false_expression =
7668                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7669
7670         type_t *const orig_true_type  = true_expression->base.type;
7671         type_t *const orig_false_type = false_expression->base.type;
7672         type_t *const true_type       = skip_typeref(orig_true_type);
7673         type_t *const false_type      = skip_typeref(orig_false_type);
7674
7675         /* 6.5.15.3 */
7676         type_t *result_type;
7677         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7678                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7679                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7680                 if (true_expression->kind == EXPR_UNARY_THROW) {
7681                         result_type = false_type;
7682                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7683                         result_type = true_type;
7684                 } else {
7685                         if (warning.other && (
7686                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7687                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7688                                         )) {
7689                                 warningf(&conditional->base.source_position,
7690                                                 "ISO C forbids conditional expression with only one void side");
7691                         }
7692                         result_type = type_void;
7693                 }
7694         } else if (is_type_arithmetic(true_type)
7695                    && is_type_arithmetic(false_type)) {
7696                 result_type = semantic_arithmetic(true_type, false_type);
7697         } else if (same_compound_type(true_type, false_type)) {
7698                 /* just take 1 of the 2 types */
7699                 result_type = true_type;
7700         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7701                 type_t *pointer_type;
7702                 type_t *other_type;
7703                 expression_t *other_expression;
7704                 if (is_type_pointer(true_type) &&
7705                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7706                         pointer_type     = true_type;
7707                         other_type       = false_type;
7708                         other_expression = false_expression;
7709                 } else {
7710                         pointer_type     = false_type;
7711                         other_type       = true_type;
7712                         other_expression = true_expression;
7713                 }
7714
7715                 if (is_null_pointer_constant(other_expression)) {
7716                         result_type = pointer_type;
7717                 } else if (is_type_pointer(other_type)) {
7718                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7719                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7720
7721                         type_t *to;
7722                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7723                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7724                                 to = type_void;
7725                         } else if (types_compatible(get_unqualified_type(to1),
7726                                                     get_unqualified_type(to2))) {
7727                                 to = to1;
7728                         } else {
7729                                 if (warning.other) {
7730                                         warningf(&conditional->base.source_position,
7731                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7732                                                         true_type, false_type);
7733                                 }
7734                                 to = type_void;
7735                         }
7736
7737                         type_t *const type =
7738                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7739                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7740                 } else if (is_type_integer(other_type)) {
7741                         if (warning.other) {
7742                                 warningf(&conditional->base.source_position,
7743                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7744                         }
7745                         result_type = pointer_type;
7746                 } else {
7747                         if (is_type_valid(other_type)) {
7748                                 type_error_incompatible("while parsing conditional",
7749                                                 &expression->base.source_position, true_type, false_type);
7750                         }
7751                         result_type = type_error_type;
7752                 }
7753         } else {
7754                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7755                         type_error_incompatible("while parsing conditional",
7756                                                 &conditional->base.source_position, true_type,
7757                                                 false_type);
7758                 }
7759                 result_type = type_error_type;
7760         }
7761
7762         conditional->true_expression
7763                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7764         conditional->false_expression
7765                 = create_implicit_cast(false_expression, result_type);
7766         conditional->base.type = result_type;
7767         return result;
7768 }
7769
7770 /**
7771  * Parse an extension expression.
7772  */
7773 static expression_t *parse_extension(void)
7774 {
7775         eat(T___extension__);
7776
7777         bool old_gcc_extension   = in_gcc_extension;
7778         in_gcc_extension         = true;
7779         expression_t *expression = parse_subexpression(PREC_UNARY);
7780         in_gcc_extension         = old_gcc_extension;
7781         return expression;
7782 }
7783
7784 /**
7785  * Parse a __builtin_classify_type() expression.
7786  */
7787 static expression_t *parse_builtin_classify_type(void)
7788 {
7789         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7790         result->base.type    = type_int;
7791
7792         eat(T___builtin_classify_type);
7793
7794         expect('(', end_error);
7795         add_anchor_token(')');
7796         expression_t *expression = parse_expression();
7797         rem_anchor_token(')');
7798         expect(')', end_error);
7799         result->classify_type.type_expression = expression;
7800
7801         return result;
7802 end_error:
7803         return create_invalid_expression();
7804 }
7805
7806 /**
7807  * Parse a delete expression
7808  * ISO/IEC 14882:1998(E) §5.3.5
7809  */
7810 static expression_t *parse_delete(void)
7811 {
7812         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7813         result->base.type          = type_void;
7814
7815         eat(T_delete);
7816
7817         if (next_if('[')) {
7818                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7819                 expect(']', end_error);
7820 end_error:;
7821         }
7822
7823         expression_t *const value = parse_subexpression(PREC_CAST);
7824         result->unary.value = value;
7825
7826         type_t *const type = skip_typeref(value->base.type);
7827         if (!is_type_pointer(type)) {
7828                 if (is_type_valid(type)) {
7829                         errorf(&value->base.source_position,
7830                                         "operand of delete must have pointer type");
7831                 }
7832         } else if (warning.other &&
7833                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7834                 warningf(&value->base.source_position,
7835                                 "deleting 'void*' is undefined");
7836         }
7837
7838         return result;
7839 }
7840
7841 /**
7842  * Parse a throw expression
7843  * ISO/IEC 14882:1998(E) §15:1
7844  */
7845 static expression_t *parse_throw(void)
7846 {
7847         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7848         result->base.type          = type_void;
7849
7850         eat(T_throw);
7851
7852         expression_t *value = NULL;
7853         switch (token.type) {
7854                 EXPRESSION_START {
7855                         value = parse_assignment_expression();
7856                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7857                         type_t *const orig_type = value->base.type;
7858                         type_t *const type      = skip_typeref(orig_type);
7859                         if (is_type_incomplete(type)) {
7860                                 errorf(&value->base.source_position,
7861                                                 "cannot throw object of incomplete type '%T'", orig_type);
7862                         } else if (is_type_pointer(type)) {
7863                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7864                                 if (is_type_incomplete(points_to) &&
7865                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7866                                         errorf(&value->base.source_position,
7867                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7868                                 }
7869                         }
7870                 }
7871
7872                 default:
7873                         break;
7874         }
7875         result->unary.value = value;
7876
7877         return result;
7878 }
7879
7880 static bool check_pointer_arithmetic(const source_position_t *source_position,
7881                                      type_t *pointer_type,
7882                                      type_t *orig_pointer_type)
7883 {
7884         type_t *points_to = pointer_type->pointer.points_to;
7885         points_to = skip_typeref(points_to);
7886
7887         if (is_type_incomplete(points_to)) {
7888                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7889                         errorf(source_position,
7890                                "arithmetic with pointer to incomplete type '%T' not allowed",
7891                                orig_pointer_type);
7892                         return false;
7893                 } else if (warning.pointer_arith) {
7894                         warningf(source_position,
7895                                  "pointer of type '%T' used in arithmetic",
7896                                  orig_pointer_type);
7897                 }
7898         } else if (is_type_function(points_to)) {
7899                 if (!GNU_MODE) {
7900                         errorf(source_position,
7901                                "arithmetic with pointer to function type '%T' not allowed",
7902                                orig_pointer_type);
7903                         return false;
7904                 } else if (warning.pointer_arith) {
7905                         warningf(source_position,
7906                                  "pointer to a function '%T' used in arithmetic",
7907                                  orig_pointer_type);
7908                 }
7909         }
7910         return true;
7911 }
7912
7913 static bool is_lvalue(const expression_t *expression)
7914 {
7915         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7916         switch (expression->kind) {
7917         case EXPR_ARRAY_ACCESS:
7918         case EXPR_COMPOUND_LITERAL:
7919         case EXPR_REFERENCE:
7920         case EXPR_SELECT:
7921         case EXPR_UNARY_DEREFERENCE:
7922                 return true;
7923
7924         default: {
7925                 type_t *type = skip_typeref(expression->base.type);
7926                 return
7927                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7928                         is_type_reference(type) ||
7929                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7930                          * error before, which maybe prevented properly recognizing it as
7931                          * lvalue. */
7932                         !is_type_valid(type);
7933         }
7934         }
7935 }
7936
7937 static void semantic_incdec(unary_expression_t *expression)
7938 {
7939         type_t *const orig_type = expression->value->base.type;
7940         type_t *const type      = skip_typeref(orig_type);
7941         if (is_type_pointer(type)) {
7942                 if (!check_pointer_arithmetic(&expression->base.source_position,
7943                                               type, orig_type)) {
7944                         return;
7945                 }
7946         } else if (!is_type_real(type) && is_type_valid(type)) {
7947                 /* TODO: improve error message */
7948                 errorf(&expression->base.source_position,
7949                        "operation needs an arithmetic or pointer type");
7950                 return;
7951         }
7952         if (!is_lvalue(expression->value)) {
7953                 /* TODO: improve error message */
7954                 errorf(&expression->base.source_position, "lvalue required as operand");
7955         }
7956         expression->base.type = orig_type;
7957 }
7958
7959 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7960 {
7961         type_t *const orig_type = expression->value->base.type;
7962         type_t *const type      = skip_typeref(orig_type);
7963         if (!is_type_arithmetic(type)) {
7964                 if (is_type_valid(type)) {
7965                         /* TODO: improve error message */
7966                         errorf(&expression->base.source_position,
7967                                 "operation needs an arithmetic type");
7968                 }
7969                 return;
7970         }
7971
7972         expression->base.type = orig_type;
7973 }
7974
7975 static void semantic_unexpr_plus(unary_expression_t *expression)
7976 {
7977         semantic_unexpr_arithmetic(expression);
7978         if (warning.traditional)
7979                 warningf(&expression->base.source_position,
7980                         "traditional C rejects the unary plus operator");
7981 }
7982
7983 static void semantic_not(unary_expression_t *expression)
7984 {
7985         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7986         semantic_condition(expression->value, "operand of !");
7987         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7988 }
7989
7990 static void semantic_unexpr_integer(unary_expression_t *expression)
7991 {
7992         type_t *const orig_type = expression->value->base.type;
7993         type_t *const type      = skip_typeref(orig_type);
7994         if (!is_type_integer(type)) {
7995                 if (is_type_valid(type)) {
7996                         errorf(&expression->base.source_position,
7997                                "operand of ~ must be of integer type");
7998                 }
7999                 return;
8000         }
8001
8002         expression->base.type = orig_type;
8003 }
8004
8005 static void semantic_dereference(unary_expression_t *expression)
8006 {
8007         type_t *const orig_type = expression->value->base.type;
8008         type_t *const type      = skip_typeref(orig_type);
8009         if (!is_type_pointer(type)) {
8010                 if (is_type_valid(type)) {
8011                         errorf(&expression->base.source_position,
8012                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8013                 }
8014                 return;
8015         }
8016
8017         type_t *result_type   = type->pointer.points_to;
8018         result_type           = automatic_type_conversion(result_type);
8019         expression->base.type = result_type;
8020 }
8021
8022 /**
8023  * Record that an address is taken (expression represents an lvalue).
8024  *
8025  * @param expression       the expression
8026  * @param may_be_register  if true, the expression might be an register
8027  */
8028 static void set_address_taken(expression_t *expression, bool may_be_register)
8029 {
8030         if (expression->kind != EXPR_REFERENCE)
8031                 return;
8032
8033         entity_t *const entity = expression->reference.entity;
8034
8035         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8036                 return;
8037
8038         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8039                         && !may_be_register) {
8040                 errorf(&expression->base.source_position,
8041                        "address of register %s '%Y' requested",
8042                        get_entity_kind_name(entity->kind), entity->base.symbol);
8043         }
8044
8045         if (entity->kind == ENTITY_VARIABLE) {
8046                 entity->variable.address_taken = true;
8047         } else {
8048                 assert(entity->kind == ENTITY_PARAMETER);
8049                 entity->parameter.address_taken = true;
8050         }
8051 }
8052
8053 /**
8054  * Check the semantic of the address taken expression.
8055  */
8056 static void semantic_take_addr(unary_expression_t *expression)
8057 {
8058         expression_t *value = expression->value;
8059         value->base.type    = revert_automatic_type_conversion(value);
8060
8061         type_t *orig_type = value->base.type;
8062         type_t *type      = skip_typeref(orig_type);
8063         if (!is_type_valid(type))
8064                 return;
8065
8066         /* §6.5.3.2 */
8067         if (!is_lvalue(value)) {
8068                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8069         }
8070         if (type->kind == TYPE_BITFIELD) {
8071                 errorf(&expression->base.source_position,
8072                        "'&' not allowed on object with bitfield type '%T'",
8073                        type);
8074         }
8075
8076         set_address_taken(value, false);
8077
8078         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8079 }
8080
8081 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8082 static expression_t *parse_##unexpression_type(void)                         \
8083 {                                                                            \
8084         expression_t *unary_expression                                           \
8085                 = allocate_expression_zero(unexpression_type);                       \
8086         eat(token_type);                                                         \
8087         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
8088                                                                                  \
8089         sfunc(&unary_expression->unary);                                         \
8090                                                                                  \
8091         return unary_expression;                                                 \
8092 }
8093
8094 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8095                                semantic_unexpr_arithmetic)
8096 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8097                                semantic_unexpr_plus)
8098 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8099                                semantic_not)
8100 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8101                                semantic_dereference)
8102 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8103                                semantic_take_addr)
8104 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8105                                semantic_unexpr_integer)
8106 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8107                                semantic_incdec)
8108 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8109                                semantic_incdec)
8110
8111 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8112                                                sfunc)                         \
8113 static expression_t *parse_##unexpression_type(expression_t *left)            \
8114 {                                                                             \
8115         expression_t *unary_expression                                            \
8116                 = allocate_expression_zero(unexpression_type);                        \
8117         eat(token_type);                                                          \
8118         unary_expression->unary.value = left;                                     \
8119                                                                                   \
8120         sfunc(&unary_expression->unary);                                          \
8121                                                                               \
8122         return unary_expression;                                                  \
8123 }
8124
8125 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8126                                        EXPR_UNARY_POSTFIX_INCREMENT,
8127                                        semantic_incdec)
8128 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8129                                        EXPR_UNARY_POSTFIX_DECREMENT,
8130                                        semantic_incdec)
8131
8132 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8133 {
8134         /* TODO: handle complex + imaginary types */
8135
8136         type_left  = get_unqualified_type(type_left);
8137         type_right = get_unqualified_type(type_right);
8138
8139         /* §6.3.1.8 Usual arithmetic conversions */
8140         if (type_left == type_long_double || type_right == type_long_double) {
8141                 return type_long_double;
8142         } else if (type_left == type_double || type_right == type_double) {
8143                 return type_double;
8144         } else if (type_left == type_float || type_right == type_float) {
8145                 return type_float;
8146         }
8147
8148         type_left  = promote_integer(type_left);
8149         type_right = promote_integer(type_right);
8150
8151         if (type_left == type_right)
8152                 return type_left;
8153
8154         bool const signed_left  = is_type_signed(type_left);
8155         bool const signed_right = is_type_signed(type_right);
8156         int const  rank_left    = get_rank(type_left);
8157         int const  rank_right   = get_rank(type_right);
8158
8159         if (signed_left == signed_right)
8160                 return rank_left >= rank_right ? type_left : type_right;
8161
8162         int     s_rank;
8163         int     u_rank;
8164         type_t *s_type;
8165         type_t *u_type;
8166         if (signed_left) {
8167                 s_rank = rank_left;
8168                 s_type = type_left;
8169                 u_rank = rank_right;
8170                 u_type = type_right;
8171         } else {
8172                 s_rank = rank_right;
8173                 s_type = type_right;
8174                 u_rank = rank_left;
8175                 u_type = type_left;
8176         }
8177
8178         if (u_rank >= s_rank)
8179                 return u_type;
8180
8181         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8182          * easier here... */
8183         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8184                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8185                 return s_type;
8186
8187         switch (s_rank) {
8188                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8189                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8190                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8191
8192                 default: panic("invalid atomic type");
8193         }
8194 }
8195
8196 /**
8197  * Check the semantic restrictions for a binary expression.
8198  */
8199 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8200 {
8201         expression_t *const left            = expression->left;
8202         expression_t *const right           = expression->right;
8203         type_t       *const orig_type_left  = left->base.type;
8204         type_t       *const orig_type_right = right->base.type;
8205         type_t       *const type_left       = skip_typeref(orig_type_left);
8206         type_t       *const type_right      = skip_typeref(orig_type_right);
8207
8208         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8209                 /* TODO: improve error message */
8210                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8211                         errorf(&expression->base.source_position,
8212                                "operation needs arithmetic types");
8213                 }
8214                 return;
8215         }
8216
8217         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8218         expression->left      = create_implicit_cast(left, arithmetic_type);
8219         expression->right     = create_implicit_cast(right, arithmetic_type);
8220         expression->base.type = arithmetic_type;
8221 }
8222
8223 static void semantic_binexpr_integer(binary_expression_t *const expression)
8224 {
8225         expression_t *const left            = expression->left;
8226         expression_t *const right           = expression->right;
8227         type_t       *const orig_type_left  = left->base.type;
8228         type_t       *const orig_type_right = right->base.type;
8229         type_t       *const type_left       = skip_typeref(orig_type_left);
8230         type_t       *const type_right      = skip_typeref(orig_type_right);
8231
8232         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8233                 /* TODO: improve error message */
8234                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8235                         errorf(&expression->base.source_position,
8236                                "operation needs integer types");
8237                 }
8238                 return;
8239         }
8240
8241         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8242         expression->left      = create_implicit_cast(left, result_type);
8243         expression->right     = create_implicit_cast(right, result_type);
8244         expression->base.type = result_type;
8245 }
8246
8247 static void warn_div_by_zero(binary_expression_t const *const expression)
8248 {
8249         if (!warning.div_by_zero ||
8250             !is_type_integer(expression->base.type))
8251                 return;
8252
8253         expression_t const *const right = expression->right;
8254         /* The type of the right operand can be different for /= */
8255         if (is_type_integer(right->base.type)                    &&
8256             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8257             !fold_constant_to_bool(right)) {
8258                 warningf(&expression->base.source_position, "division by zero");
8259         }
8260 }
8261
8262 /**
8263  * Check the semantic restrictions for a div/mod expression.
8264  */
8265 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8266 {
8267         semantic_binexpr_arithmetic(expression);
8268         warn_div_by_zero(expression);
8269 }
8270
8271 static void warn_addsub_in_shift(const expression_t *const expr)
8272 {
8273         if (expr->base.parenthesized)
8274                 return;
8275
8276         char op;
8277         switch (expr->kind) {
8278                 case EXPR_BINARY_ADD: op = '+'; break;
8279                 case EXPR_BINARY_SUB: op = '-'; break;
8280                 default:              return;
8281         }
8282
8283         warningf(&expr->base.source_position,
8284                         "suggest parentheses around '%c' inside shift", op);
8285 }
8286
8287 static bool semantic_shift(binary_expression_t *expression)
8288 {
8289         expression_t *const left            = expression->left;
8290         expression_t *const right           = expression->right;
8291         type_t       *const orig_type_left  = left->base.type;
8292         type_t       *const orig_type_right = right->base.type;
8293         type_t       *      type_left       = skip_typeref(orig_type_left);
8294         type_t       *      type_right      = skip_typeref(orig_type_right);
8295
8296         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8297                 /* TODO: improve error message */
8298                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8299                         errorf(&expression->base.source_position,
8300                                "operands of shift operation must have integer types");
8301                 }
8302                 return false;
8303         }
8304
8305         type_left = promote_integer(type_left);
8306
8307         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8308                 long count = fold_constant_to_int(right);
8309                 if (count < 0) {
8310                         warningf(&right->base.source_position,
8311                                         "shift count must be non-negative");
8312                 } else if ((unsigned long)count >=
8313                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8314                         warningf(&right->base.source_position,
8315                                         "shift count must be less than type width");
8316                 }
8317         }
8318
8319         type_right        = promote_integer(type_right);
8320         expression->right = create_implicit_cast(right, type_right);
8321
8322         return true;
8323 }
8324
8325 static void semantic_shift_op(binary_expression_t *expression)
8326 {
8327         expression_t *const left  = expression->left;
8328         expression_t *const right = expression->right;
8329
8330         if (!semantic_shift(expression))
8331                 return;
8332
8333         if (warning.parentheses) {
8334                 warn_addsub_in_shift(left);
8335                 warn_addsub_in_shift(right);
8336         }
8337
8338         type_t *const orig_type_left = left->base.type;
8339         type_t *      type_left      = skip_typeref(orig_type_left);
8340
8341         type_left             = promote_integer(type_left);
8342         expression->left      = create_implicit_cast(left, type_left);
8343         expression->base.type = type_left;
8344 }
8345
8346 static void semantic_add(binary_expression_t *expression)
8347 {
8348         expression_t *const left            = expression->left;
8349         expression_t *const right           = expression->right;
8350         type_t       *const orig_type_left  = left->base.type;
8351         type_t       *const orig_type_right = right->base.type;
8352         type_t       *const type_left       = skip_typeref(orig_type_left);
8353         type_t       *const type_right      = skip_typeref(orig_type_right);
8354
8355         /* §6.5.6 */
8356         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8357                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8358                 expression->left  = create_implicit_cast(left, arithmetic_type);
8359                 expression->right = create_implicit_cast(right, arithmetic_type);
8360                 expression->base.type = arithmetic_type;
8361         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8362                 check_pointer_arithmetic(&expression->base.source_position,
8363                                          type_left, orig_type_left);
8364                 expression->base.type = type_left;
8365         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8366                 check_pointer_arithmetic(&expression->base.source_position,
8367                                          type_right, orig_type_right);
8368                 expression->base.type = type_right;
8369         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8370                 errorf(&expression->base.source_position,
8371                        "invalid operands to binary + ('%T', '%T')",
8372                        orig_type_left, orig_type_right);
8373         }
8374 }
8375
8376 static void semantic_sub(binary_expression_t *expression)
8377 {
8378         expression_t            *const left            = expression->left;
8379         expression_t            *const right           = expression->right;
8380         type_t                  *const orig_type_left  = left->base.type;
8381         type_t                  *const orig_type_right = right->base.type;
8382         type_t                  *const type_left       = skip_typeref(orig_type_left);
8383         type_t                  *const type_right      = skip_typeref(orig_type_right);
8384         source_position_t const *const pos             = &expression->base.source_position;
8385
8386         /* §5.6.5 */
8387         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8388                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8389                 expression->left        = create_implicit_cast(left, arithmetic_type);
8390                 expression->right       = create_implicit_cast(right, arithmetic_type);
8391                 expression->base.type =  arithmetic_type;
8392         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8393                 check_pointer_arithmetic(&expression->base.source_position,
8394                                          type_left, orig_type_left);
8395                 expression->base.type = type_left;
8396         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8397                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8398                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8399                 if (!types_compatible(unqual_left, unqual_right)) {
8400                         errorf(pos,
8401                                "subtracting pointers to incompatible types '%T' and '%T'",
8402                                orig_type_left, orig_type_right);
8403                 } else if (!is_type_object(unqual_left)) {
8404                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8405                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8406                                        orig_type_left);
8407                         } else if (warning.other) {
8408                                 warningf(pos, "subtracting pointers to void");
8409                         }
8410                 }
8411                 expression->base.type = type_ptrdiff_t;
8412         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8413                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8414                        orig_type_left, orig_type_right);
8415         }
8416 }
8417
8418 static void warn_string_literal_address(expression_t const* expr)
8419 {
8420         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8421                 expr = expr->unary.value;
8422                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8423                         return;
8424                 expr = expr->unary.value;
8425         }
8426
8427         if (expr->kind == EXPR_STRING_LITERAL
8428                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8429                 warningf(&expr->base.source_position,
8430                         "comparison with string literal results in unspecified behaviour");
8431         }
8432 }
8433
8434 static void warn_comparison_in_comparison(const expression_t *const expr)
8435 {
8436         if (expr->base.parenthesized)
8437                 return;
8438         switch (expr->base.kind) {
8439                 case EXPR_BINARY_LESS:
8440                 case EXPR_BINARY_GREATER:
8441                 case EXPR_BINARY_LESSEQUAL:
8442                 case EXPR_BINARY_GREATEREQUAL:
8443                 case EXPR_BINARY_NOTEQUAL:
8444                 case EXPR_BINARY_EQUAL:
8445                         warningf(&expr->base.source_position,
8446                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8447                         break;
8448                 default:
8449                         break;
8450         }
8451 }
8452
8453 static bool maybe_negative(expression_t const *const expr)
8454 {
8455         switch (is_constant_expression(expr)) {
8456                 case EXPR_CLASS_ERROR:    return false;
8457                 case EXPR_CLASS_CONSTANT: return fold_constant_to_int(expr) < 0;
8458                 default:                  return true;
8459         }
8460 }
8461
8462 /**
8463  * Check the semantics of comparison expressions.
8464  *
8465  * @param expression   The expression to check.
8466  */
8467 static void semantic_comparison(binary_expression_t *expression)
8468 {
8469         expression_t *left  = expression->left;
8470         expression_t *right = expression->right;
8471
8472         if (warning.address) {
8473                 warn_string_literal_address(left);
8474                 warn_string_literal_address(right);
8475
8476                 expression_t const* const func_left = get_reference_address(left);
8477                 if (func_left != NULL && is_null_pointer_constant(right)) {
8478                         warningf(&expression->base.source_position,
8479                                  "the address of '%Y' will never be NULL",
8480                                  func_left->reference.entity->base.symbol);
8481                 }
8482
8483                 expression_t const* const func_right = get_reference_address(right);
8484                 if (func_right != NULL && is_null_pointer_constant(right)) {
8485                         warningf(&expression->base.source_position,
8486                                  "the address of '%Y' will never be NULL",
8487                                  func_right->reference.entity->base.symbol);
8488                 }
8489         }
8490
8491         if (warning.parentheses) {
8492                 warn_comparison_in_comparison(left);
8493                 warn_comparison_in_comparison(right);
8494         }
8495
8496         type_t *orig_type_left  = left->base.type;
8497         type_t *orig_type_right = right->base.type;
8498         type_t *type_left       = skip_typeref(orig_type_left);
8499         type_t *type_right      = skip_typeref(orig_type_right);
8500
8501         /* TODO non-arithmetic types */
8502         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8503                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8504
8505                 /* test for signed vs unsigned compares */
8506                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8507                         bool const signed_left  = is_type_signed(type_left);
8508                         bool const signed_right = is_type_signed(type_right);
8509                         if (signed_left != signed_right) {
8510                                 /* FIXME long long needs better const folding magic */
8511                                 /* TODO check whether constant value can be represented by other type */
8512                                 if ((signed_left  && maybe_negative(left)) ||
8513                                                 (signed_right && maybe_negative(right))) {
8514                                         warningf(&expression->base.source_position,
8515                                                         "comparison between signed and unsigned");
8516                                 }
8517                         }
8518                 }
8519
8520                 expression->left        = create_implicit_cast(left, arithmetic_type);
8521                 expression->right       = create_implicit_cast(right, arithmetic_type);
8522                 expression->base.type   = arithmetic_type;
8523                 if (warning.float_equal &&
8524                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8525                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8526                     is_type_float(arithmetic_type)) {
8527                         warningf(&expression->base.source_position,
8528                                  "comparing floating point with == or != is unsafe");
8529                 }
8530         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8531                 /* TODO check compatibility */
8532         } else if (is_type_pointer(type_left)) {
8533                 expression->right = create_implicit_cast(right, type_left);
8534         } else if (is_type_pointer(type_right)) {
8535                 expression->left = create_implicit_cast(left, type_right);
8536         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8537                 type_error_incompatible("invalid operands in comparison",
8538                                         &expression->base.source_position,
8539                                         type_left, type_right);
8540         }
8541         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8542 }
8543
8544 /**
8545  * Checks if a compound type has constant fields.
8546  */
8547 static bool has_const_fields(const compound_type_t *type)
8548 {
8549         compound_t *compound = type->compound;
8550         entity_t   *entry    = compound->members.entities;
8551
8552         for (; entry != NULL; entry = entry->base.next) {
8553                 if (!is_declaration(entry))
8554                         continue;
8555
8556                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8557                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8558                         return true;
8559         }
8560
8561         return false;
8562 }
8563
8564 static bool is_valid_assignment_lhs(expression_t const* const left)
8565 {
8566         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8567         type_t *const type_left      = skip_typeref(orig_type_left);
8568
8569         if (!is_lvalue(left)) {
8570                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8571                        left);
8572                 return false;
8573         }
8574
8575         if (left->kind == EXPR_REFERENCE
8576                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8577                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8578                 return false;
8579         }
8580
8581         if (is_type_array(type_left)) {
8582                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8583                 return false;
8584         }
8585         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8586                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8587                        orig_type_left);
8588                 return false;
8589         }
8590         if (is_type_incomplete(type_left)) {
8591                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8592                        left, orig_type_left);
8593                 return false;
8594         }
8595         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8596                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8597                        left, orig_type_left);
8598                 return false;
8599         }
8600
8601         return true;
8602 }
8603
8604 static void semantic_arithmetic_assign(binary_expression_t *expression)
8605 {
8606         expression_t *left            = expression->left;
8607         expression_t *right           = expression->right;
8608         type_t       *orig_type_left  = left->base.type;
8609         type_t       *orig_type_right = right->base.type;
8610
8611         if (!is_valid_assignment_lhs(left))
8612                 return;
8613
8614         type_t *type_left  = skip_typeref(orig_type_left);
8615         type_t *type_right = skip_typeref(orig_type_right);
8616
8617         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8618                 /* TODO: improve error message */
8619                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8620                         errorf(&expression->base.source_position,
8621                                "operation needs arithmetic types");
8622                 }
8623                 return;
8624         }
8625
8626         /* combined instructions are tricky. We can't create an implicit cast on
8627          * the left side, because we need the uncasted form for the store.
8628          * The ast2firm pass has to know that left_type must be right_type
8629          * for the arithmetic operation and create a cast by itself */
8630         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8631         expression->right       = create_implicit_cast(right, arithmetic_type);
8632         expression->base.type   = type_left;
8633 }
8634
8635 static void semantic_divmod_assign(binary_expression_t *expression)
8636 {
8637         semantic_arithmetic_assign(expression);
8638         warn_div_by_zero(expression);
8639 }
8640
8641 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8642 {
8643         expression_t *const left            = expression->left;
8644         expression_t *const right           = expression->right;
8645         type_t       *const orig_type_left  = left->base.type;
8646         type_t       *const orig_type_right = right->base.type;
8647         type_t       *const type_left       = skip_typeref(orig_type_left);
8648         type_t       *const type_right      = skip_typeref(orig_type_right);
8649
8650         if (!is_valid_assignment_lhs(left))
8651                 return;
8652
8653         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8654                 /* combined instructions are tricky. We can't create an implicit cast on
8655                  * the left side, because we need the uncasted form for the store.
8656                  * The ast2firm pass has to know that left_type must be right_type
8657                  * for the arithmetic operation and create a cast by itself */
8658                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8659                 expression->right     = create_implicit_cast(right, arithmetic_type);
8660                 expression->base.type = type_left;
8661         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8662                 check_pointer_arithmetic(&expression->base.source_position,
8663                                          type_left, orig_type_left);
8664                 expression->base.type = type_left;
8665         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8666                 errorf(&expression->base.source_position,
8667                        "incompatible types '%T' and '%T' in assignment",
8668                        orig_type_left, orig_type_right);
8669         }
8670 }
8671
8672 static void semantic_integer_assign(binary_expression_t *expression)
8673 {
8674         expression_t *left            = expression->left;
8675         expression_t *right           = expression->right;
8676         type_t       *orig_type_left  = left->base.type;
8677         type_t       *orig_type_right = right->base.type;
8678
8679         if (!is_valid_assignment_lhs(left))
8680                 return;
8681
8682         type_t *type_left  = skip_typeref(orig_type_left);
8683         type_t *type_right = skip_typeref(orig_type_right);
8684
8685         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8686                 /* TODO: improve error message */
8687                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8688                         errorf(&expression->base.source_position,
8689                                "operation needs integer types");
8690                 }
8691                 return;
8692         }
8693
8694         /* combined instructions are tricky. We can't create an implicit cast on
8695          * the left side, because we need the uncasted form for the store.
8696          * The ast2firm pass has to know that left_type must be right_type
8697          * for the arithmetic operation and create a cast by itself */
8698         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8699         expression->right       = create_implicit_cast(right, arithmetic_type);
8700         expression->base.type   = type_left;
8701 }
8702
8703 static void semantic_shift_assign(binary_expression_t *expression)
8704 {
8705         expression_t *left           = expression->left;
8706
8707         if (!is_valid_assignment_lhs(left))
8708                 return;
8709
8710         if (!semantic_shift(expression))
8711                 return;
8712
8713         expression->base.type = skip_typeref(left->base.type);
8714 }
8715
8716 static void warn_logical_and_within_or(const expression_t *const expr)
8717 {
8718         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8719                 return;
8720         if (expr->base.parenthesized)
8721                 return;
8722         warningf(&expr->base.source_position,
8723                         "suggest parentheses around && within ||");
8724 }
8725
8726 /**
8727  * Check the semantic restrictions of a logical expression.
8728  */
8729 static void semantic_logical_op(binary_expression_t *expression)
8730 {
8731         /* §6.5.13:2  Each of the operands shall have scalar type.
8732          * §6.5.14:2  Each of the operands shall have scalar type. */
8733         semantic_condition(expression->left,   "left operand of logical operator");
8734         semantic_condition(expression->right, "right operand of logical operator");
8735         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8736                         warning.parentheses) {
8737                 warn_logical_and_within_or(expression->left);
8738                 warn_logical_and_within_or(expression->right);
8739         }
8740         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8741 }
8742
8743 /**
8744  * Check the semantic restrictions of a binary assign expression.
8745  */
8746 static void semantic_binexpr_assign(binary_expression_t *expression)
8747 {
8748         expression_t *left           = expression->left;
8749         type_t       *orig_type_left = left->base.type;
8750
8751         if (!is_valid_assignment_lhs(left))
8752                 return;
8753
8754         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8755         report_assign_error(error, orig_type_left, expression->right,
8756                         "assignment", &left->base.source_position);
8757         expression->right = create_implicit_cast(expression->right, orig_type_left);
8758         expression->base.type = orig_type_left;
8759 }
8760
8761 /**
8762  * Determine if the outermost operation (or parts thereof) of the given
8763  * expression has no effect in order to generate a warning about this fact.
8764  * Therefore in some cases this only examines some of the operands of the
8765  * expression (see comments in the function and examples below).
8766  * Examples:
8767  *   f() + 23;    // warning, because + has no effect
8768  *   x || f();    // no warning, because x controls execution of f()
8769  *   x ? y : f(); // warning, because y has no effect
8770  *   (void)x;     // no warning to be able to suppress the warning
8771  * This function can NOT be used for an "expression has definitely no effect"-
8772  * analysis. */
8773 static bool expression_has_effect(const expression_t *const expr)
8774 {
8775         switch (expr->kind) {
8776                 case EXPR_UNKNOWN:                    break;
8777                 case EXPR_INVALID:                    return true; /* do NOT warn */
8778                 case EXPR_REFERENCE:                  return false;
8779                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8780                 case EXPR_LABEL_ADDRESS:              return false;
8781
8782                 /* suppress the warning for microsoft __noop operations */
8783                 case EXPR_LITERAL_MS_NOOP:            return true;
8784                 case EXPR_LITERAL_BOOLEAN:
8785                 case EXPR_LITERAL_CHARACTER:
8786                 case EXPR_LITERAL_WIDE_CHARACTER:
8787                 case EXPR_LITERAL_INTEGER:
8788                 case EXPR_LITERAL_INTEGER_OCTAL:
8789                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8790                 case EXPR_LITERAL_FLOATINGPOINT:
8791                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8792                 case EXPR_STRING_LITERAL:             return false;
8793                 case EXPR_WIDE_STRING_LITERAL:        return false;
8794
8795                 case EXPR_CALL: {
8796                         const call_expression_t *const call = &expr->call;
8797                         if (call->function->kind != EXPR_REFERENCE)
8798                                 return true;
8799
8800                         switch (call->function->reference.entity->function.btk) {
8801                                 /* FIXME: which builtins have no effect? */
8802                                 default:                      return true;
8803                         }
8804                 }
8805
8806                 /* Generate the warning if either the left or right hand side of a
8807                  * conditional expression has no effect */
8808                 case EXPR_CONDITIONAL: {
8809                         conditional_expression_t const *const cond = &expr->conditional;
8810                         expression_t             const *const t    = cond->true_expression;
8811                         return
8812                                 (t == NULL || expression_has_effect(t)) &&
8813                                 expression_has_effect(cond->false_expression);
8814                 }
8815
8816                 case EXPR_SELECT:                     return false;
8817                 case EXPR_ARRAY_ACCESS:               return false;
8818                 case EXPR_SIZEOF:                     return false;
8819                 case EXPR_CLASSIFY_TYPE:              return false;
8820                 case EXPR_ALIGNOF:                    return false;
8821
8822                 case EXPR_FUNCNAME:                   return false;
8823                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8824                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8825                 case EXPR_OFFSETOF:                   return false;
8826                 case EXPR_VA_START:                   return true;
8827                 case EXPR_VA_ARG:                     return true;
8828                 case EXPR_VA_COPY:                    return true;
8829                 case EXPR_STATEMENT:                  return true; // TODO
8830                 case EXPR_COMPOUND_LITERAL:           return false;
8831
8832                 case EXPR_UNARY_NEGATE:               return false;
8833                 case EXPR_UNARY_PLUS:                 return false;
8834                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8835                 case EXPR_UNARY_NOT:                  return false;
8836                 case EXPR_UNARY_DEREFERENCE:          return false;
8837                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8838                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8839                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8840                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8841                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8842
8843                 /* Treat void casts as if they have an effect in order to being able to
8844                  * suppress the warning */
8845                 case EXPR_UNARY_CAST: {
8846                         type_t *const type = skip_typeref(expr->base.type);
8847                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8848                 }
8849
8850                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8851                 case EXPR_UNARY_ASSUME:               return true;
8852                 case EXPR_UNARY_DELETE:               return true;
8853                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8854                 case EXPR_UNARY_THROW:                return true;
8855
8856                 case EXPR_BINARY_ADD:                 return false;
8857                 case EXPR_BINARY_SUB:                 return false;
8858                 case EXPR_BINARY_MUL:                 return false;
8859                 case EXPR_BINARY_DIV:                 return false;
8860                 case EXPR_BINARY_MOD:                 return false;
8861                 case EXPR_BINARY_EQUAL:               return false;
8862                 case EXPR_BINARY_NOTEQUAL:            return false;
8863                 case EXPR_BINARY_LESS:                return false;
8864                 case EXPR_BINARY_LESSEQUAL:           return false;
8865                 case EXPR_BINARY_GREATER:             return false;
8866                 case EXPR_BINARY_GREATEREQUAL:        return false;
8867                 case EXPR_BINARY_BITWISE_AND:         return false;
8868                 case EXPR_BINARY_BITWISE_OR:          return false;
8869                 case EXPR_BINARY_BITWISE_XOR:         return false;
8870                 case EXPR_BINARY_SHIFTLEFT:           return false;
8871                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8872                 case EXPR_BINARY_ASSIGN:              return true;
8873                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8874                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8875                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8876                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8877                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8878                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8879                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8880                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8881                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8882                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8883
8884                 /* Only examine the right hand side of && and ||, because the left hand
8885                  * side already has the effect of controlling the execution of the right
8886                  * hand side */
8887                 case EXPR_BINARY_LOGICAL_AND:
8888                 case EXPR_BINARY_LOGICAL_OR:
8889                 /* Only examine the right hand side of a comma expression, because the left
8890                  * hand side has a separate warning */
8891                 case EXPR_BINARY_COMMA:
8892                         return expression_has_effect(expr->binary.right);
8893
8894                 case EXPR_BINARY_ISGREATER:           return false;
8895                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8896                 case EXPR_BINARY_ISLESS:              return false;
8897                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8898                 case EXPR_BINARY_ISLESSGREATER:       return false;
8899                 case EXPR_BINARY_ISUNORDERED:         return false;
8900         }
8901
8902         internal_errorf(HERE, "unexpected expression");
8903 }
8904
8905 static void semantic_comma(binary_expression_t *expression)
8906 {
8907         if (warning.unused_value) {
8908                 const expression_t *const left = expression->left;
8909                 if (!expression_has_effect(left)) {
8910                         warningf(&left->base.source_position,
8911                                  "left-hand operand of comma expression has no effect");
8912                 }
8913         }
8914         expression->base.type = expression->right->base.type;
8915 }
8916
8917 /**
8918  * @param prec_r precedence of the right operand
8919  */
8920 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8921 static expression_t *parse_##binexpression_type(expression_t *left)          \
8922 {                                                                            \
8923         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8924         binexpr->binary.left  = left;                                            \
8925         eat(token_type);                                                         \
8926                                                                              \
8927         expression_t *right = parse_subexpression(prec_r);                       \
8928                                                                              \
8929         binexpr->binary.right = right;                                           \
8930         sfunc(&binexpr->binary);                                                 \
8931                                                                              \
8932         return binexpr;                                                          \
8933 }
8934
8935 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8936 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8937 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8938 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8939 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8940 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8941 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8942 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8943 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8944 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8945 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8946 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8947 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8948 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8949 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8950 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8951 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8952 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8953 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8954 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8955 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8956 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8957 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8958 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8959 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8960 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8961 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8962 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8963 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8964 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8965
8966
8967 static expression_t *parse_subexpression(precedence_t precedence)
8968 {
8969         if (token.type < 0) {
8970                 return expected_expression_error();
8971         }
8972
8973         expression_parser_function_t *parser
8974                 = &expression_parsers[token.type];
8975         source_position_t             source_position = token.source_position;
8976         expression_t                 *left;
8977
8978         if (parser->parser != NULL) {
8979                 left = parser->parser();
8980         } else {
8981                 left = parse_primary_expression();
8982         }
8983         assert(left != NULL);
8984         left->base.source_position = source_position;
8985
8986         while (true) {
8987                 if (token.type < 0) {
8988                         return expected_expression_error();
8989                 }
8990
8991                 parser = &expression_parsers[token.type];
8992                 if (parser->infix_parser == NULL)
8993                         break;
8994                 if (parser->infix_precedence < precedence)
8995                         break;
8996
8997                 left = parser->infix_parser(left);
8998
8999                 assert(left != NULL);
9000                 assert(left->kind != EXPR_UNKNOWN);
9001                 left->base.source_position = source_position;
9002         }
9003
9004         return left;
9005 }
9006
9007 /**
9008  * Parse an expression.
9009  */
9010 static expression_t *parse_expression(void)
9011 {
9012         return parse_subexpression(PREC_EXPRESSION);
9013 }
9014
9015 /**
9016  * Register a parser for a prefix-like operator.
9017  *
9018  * @param parser      the parser function
9019  * @param token_type  the token type of the prefix token
9020  */
9021 static void register_expression_parser(parse_expression_function parser,
9022                                        int token_type)
9023 {
9024         expression_parser_function_t *entry = &expression_parsers[token_type];
9025
9026         if (entry->parser != NULL) {
9027                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9028                 panic("trying to register multiple expression parsers for a token");
9029         }
9030         entry->parser = parser;
9031 }
9032
9033 /**
9034  * Register a parser for an infix operator with given precedence.
9035  *
9036  * @param parser      the parser function
9037  * @param token_type  the token type of the infix operator
9038  * @param precedence  the precedence of the operator
9039  */
9040 static void register_infix_parser(parse_expression_infix_function parser,
9041                                   int token_type, precedence_t precedence)
9042 {
9043         expression_parser_function_t *entry = &expression_parsers[token_type];
9044
9045         if (entry->infix_parser != NULL) {
9046                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9047                 panic("trying to register multiple infix expression parsers for a "
9048                       "token");
9049         }
9050         entry->infix_parser     = parser;
9051         entry->infix_precedence = precedence;
9052 }
9053
9054 /**
9055  * Initialize the expression parsers.
9056  */
9057 static void init_expression_parsers(void)
9058 {
9059         memset(&expression_parsers, 0, sizeof(expression_parsers));
9060
9061         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9062         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9063         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9064         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9065         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9066         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9067         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9068         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9069         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9070         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9071         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9072         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9073         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9074         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9075         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9076         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9077         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9078         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9079         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9080         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9081         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9082         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9083         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9084         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9085         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9086         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9087         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9088         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9089         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9090         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9091         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9092         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9093         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9094         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9095         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9096         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9097         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9098
9099         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9100         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9101         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9102         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9103         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9104         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9105         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9106         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9107         register_expression_parser(parse_sizeof,                      T_sizeof);
9108         register_expression_parser(parse_alignof,                     T___alignof__);
9109         register_expression_parser(parse_extension,                   T___extension__);
9110         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9111         register_expression_parser(parse_delete,                      T_delete);
9112         register_expression_parser(parse_throw,                       T_throw);
9113 }
9114
9115 /**
9116  * Parse a asm statement arguments specification.
9117  */
9118 static asm_argument_t *parse_asm_arguments(bool is_out)
9119 {
9120         asm_argument_t  *result = NULL;
9121         asm_argument_t **anchor = &result;
9122
9123         while (token.type == T_STRING_LITERAL || token.type == '[') {
9124                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9125                 memset(argument, 0, sizeof(argument[0]));
9126
9127                 if (next_if('[')) {
9128                         if (token.type != T_IDENTIFIER) {
9129                                 parse_error_expected("while parsing asm argument",
9130                                                      T_IDENTIFIER, NULL);
9131                                 return NULL;
9132                         }
9133                         argument->symbol = token.symbol;
9134
9135                         expect(']', end_error);
9136                 }
9137
9138                 argument->constraints = parse_string_literals();
9139                 expect('(', end_error);
9140                 add_anchor_token(')');
9141                 expression_t *expression = parse_expression();
9142                 rem_anchor_token(')');
9143                 if (is_out) {
9144                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9145                          * change size or type representation (e.g. int -> long is ok, but
9146                          * int -> float is not) */
9147                         if (expression->kind == EXPR_UNARY_CAST) {
9148                                 type_t      *const type = expression->base.type;
9149                                 type_kind_t  const kind = type->kind;
9150                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9151                                         unsigned flags;
9152                                         unsigned size;
9153                                         if (kind == TYPE_ATOMIC) {
9154                                                 atomic_type_kind_t const akind = type->atomic.akind;
9155                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9156                                                 size  = get_atomic_type_size(akind);
9157                                         } else {
9158                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9159                                                 size  = get_atomic_type_size(get_intptr_kind());
9160                                         }
9161
9162                                         do {
9163                                                 expression_t *const value      = expression->unary.value;
9164                                                 type_t       *const value_type = value->base.type;
9165                                                 type_kind_t   const value_kind = value_type->kind;
9166
9167                                                 unsigned value_flags;
9168                                                 unsigned value_size;
9169                                                 if (value_kind == TYPE_ATOMIC) {
9170                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9171                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9172                                                         value_size  = get_atomic_type_size(value_akind);
9173                                                 } else if (value_kind == TYPE_POINTER) {
9174                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9175                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9176                                                 } else {
9177                                                         break;
9178                                                 }
9179
9180                                                 if (value_flags != flags || value_size != size)
9181                                                         break;
9182
9183                                                 expression = value;
9184                                         } while (expression->kind == EXPR_UNARY_CAST);
9185                                 }
9186                         }
9187
9188                         if (!is_lvalue(expression)) {
9189                                 errorf(&expression->base.source_position,
9190                                        "asm output argument is not an lvalue");
9191                         }
9192
9193                         if (argument->constraints.begin[0] == '=')
9194                                 determine_lhs_ent(expression, NULL);
9195                         else
9196                                 mark_vars_read(expression, NULL);
9197                 } else {
9198                         mark_vars_read(expression, NULL);
9199                 }
9200                 argument->expression = expression;
9201                 expect(')', end_error);
9202
9203                 set_address_taken(expression, true);
9204
9205                 *anchor = argument;
9206                 anchor  = &argument->next;
9207
9208                 if (!next_if(','))
9209                         break;
9210         }
9211
9212         return result;
9213 end_error:
9214         return NULL;
9215 }
9216
9217 /**
9218  * Parse a asm statement clobber specification.
9219  */
9220 static asm_clobber_t *parse_asm_clobbers(void)
9221 {
9222         asm_clobber_t *result  = NULL;
9223         asm_clobber_t **anchor = &result;
9224
9225         while (token.type == T_STRING_LITERAL) {
9226                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9227                 clobber->clobber       = parse_string_literals();
9228
9229                 *anchor = clobber;
9230                 anchor  = &clobber->next;
9231
9232                 if (!next_if(','))
9233                         break;
9234         }
9235
9236         return result;
9237 }
9238
9239 /**
9240  * Parse an asm statement.
9241  */
9242 static statement_t *parse_asm_statement(void)
9243 {
9244         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9245         asm_statement_t *asm_statement = &statement->asms;
9246
9247         eat(T_asm);
9248
9249         if (next_if(T_volatile))
9250                 asm_statement->is_volatile = true;
9251
9252         expect('(', end_error);
9253         add_anchor_token(')');
9254         if (token.type != T_STRING_LITERAL) {
9255                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
9256                 goto end_of_asm;
9257         }
9258         asm_statement->asm_text = parse_string_literals();
9259
9260         add_anchor_token(':');
9261         if (!next_if(':')) {
9262                 rem_anchor_token(':');
9263                 goto end_of_asm;
9264         }
9265
9266         asm_statement->outputs = parse_asm_arguments(true);
9267         if (!next_if(':')) {
9268                 rem_anchor_token(':');
9269                 goto end_of_asm;
9270         }
9271
9272         asm_statement->inputs = parse_asm_arguments(false);
9273         if (!next_if(':')) {
9274                 rem_anchor_token(':');
9275                 goto end_of_asm;
9276         }
9277         rem_anchor_token(':');
9278
9279         asm_statement->clobbers = parse_asm_clobbers();
9280
9281 end_of_asm:
9282         rem_anchor_token(')');
9283         expect(')', end_error);
9284         expect(';', end_error);
9285
9286         if (asm_statement->outputs == NULL) {
9287                 /* GCC: An 'asm' instruction without any output operands will be treated
9288                  * identically to a volatile 'asm' instruction. */
9289                 asm_statement->is_volatile = true;
9290         }
9291
9292         return statement;
9293 end_error:
9294         return create_invalid_statement();
9295 }
9296
9297 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9298 {
9299         statement_t *inner_stmt;
9300         switch (token.type) {
9301                 case '}':
9302                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9303                         inner_stmt = create_invalid_statement();
9304                         break;
9305
9306                 case ';':
9307                         if (label->kind == STATEMENT_LABEL) {
9308                                 /* Eat an empty statement here, to avoid the warning about an empty
9309                                  * statement after a label.  label:; is commonly used to have a label
9310                                  * before a closing brace. */
9311                                 inner_stmt = create_empty_statement();
9312                                 next_token();
9313                                 break;
9314                         }
9315                         /* FALLTHROUGH */
9316
9317                 default:
9318                         inner_stmt = parse_statement();
9319                         /* ISO/IEC 14882:1998(E) §6:1/§6.7  Declarations are statements */
9320                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9321                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9322                         }
9323                         break;
9324         }
9325         return inner_stmt;
9326 }
9327
9328 /**
9329  * Parse a case statement.
9330  */
9331 static statement_t *parse_case_statement(void)
9332 {
9333         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9334         source_position_t *const pos       = &statement->base.source_position;
9335
9336         eat(T_case);
9337
9338         expression_t *const expression   = parse_expression();
9339         statement->case_label.expression = expression;
9340         expression_classification_t const expr_class = is_constant_expression(expression);
9341         if (expr_class != EXPR_CLASS_CONSTANT) {
9342                 if (expr_class != EXPR_CLASS_ERROR) {
9343                         errorf(pos, "case label does not reduce to an integer constant");
9344                 }
9345                 statement->case_label.is_bad = true;
9346         } else {
9347                 long const val = fold_constant_to_int(expression);
9348                 statement->case_label.first_case = val;
9349                 statement->case_label.last_case  = val;
9350         }
9351
9352         if (GNU_MODE) {
9353                 if (next_if(T_DOTDOTDOT)) {
9354                         expression_t *const end_range   = parse_expression();
9355                         statement->case_label.end_range = end_range;
9356                         expression_classification_t const end_class = is_constant_expression(end_range);
9357                         if (end_class != EXPR_CLASS_CONSTANT) {
9358                                 if (end_class != EXPR_CLASS_ERROR) {
9359                                         errorf(pos, "case range does not reduce to an integer constant");
9360                                 }
9361                                 statement->case_label.is_bad = true;
9362                         } else {
9363                                 long const val = fold_constant_to_int(end_range);
9364                                 statement->case_label.last_case = val;
9365
9366                                 if (warning.other && val < statement->case_label.first_case) {
9367                                         statement->case_label.is_empty_range = true;
9368                                         warningf(pos, "empty range specified");
9369                                 }
9370                         }
9371                 }
9372         }
9373
9374         PUSH_PARENT(statement);
9375
9376         expect(':', end_error);
9377 end_error:
9378
9379         if (current_switch != NULL) {
9380                 if (! statement->case_label.is_bad) {
9381                         /* Check for duplicate case values */
9382                         case_label_statement_t *c = &statement->case_label;
9383                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9384                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9385                                         continue;
9386
9387                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9388                                         continue;
9389
9390                                 errorf(pos, "duplicate case value (previously used %P)",
9391                                        &l->base.source_position);
9392                                 break;
9393                         }
9394                 }
9395                 /* link all cases into the switch statement */
9396                 if (current_switch->last_case == NULL) {
9397                         current_switch->first_case      = &statement->case_label;
9398                 } else {
9399                         current_switch->last_case->next = &statement->case_label;
9400                 }
9401                 current_switch->last_case = &statement->case_label;
9402         } else {
9403                 errorf(pos, "case label not within a switch statement");
9404         }
9405
9406         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9407
9408         POP_PARENT;
9409         return statement;
9410 }
9411
9412 /**
9413  * Parse a default statement.
9414  */
9415 static statement_t *parse_default_statement(void)
9416 {
9417         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9418
9419         eat(T_default);
9420
9421         PUSH_PARENT(statement);
9422
9423         expect(':', end_error);
9424 end_error:
9425
9426         if (current_switch != NULL) {
9427                 const case_label_statement_t *def_label = current_switch->default_label;
9428                 if (def_label != NULL) {
9429                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9430                                &def_label->base.source_position);
9431                 } else {
9432                         current_switch->default_label = &statement->case_label;
9433
9434                         /* link all cases into the switch statement */
9435                         if (current_switch->last_case == NULL) {
9436                                 current_switch->first_case      = &statement->case_label;
9437                         } else {
9438                                 current_switch->last_case->next = &statement->case_label;
9439                         }
9440                         current_switch->last_case = &statement->case_label;
9441                 }
9442         } else {
9443                 errorf(&statement->base.source_position,
9444                         "'default' label not within a switch statement");
9445         }
9446
9447         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9448
9449         POP_PARENT;
9450         return statement;
9451 }
9452
9453 /**
9454  * Parse a label statement.
9455  */
9456 static statement_t *parse_label_statement(void)
9457 {
9458         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9459         label_t     *const label     = get_label();
9460         statement->label.label = label;
9461
9462         PUSH_PARENT(statement);
9463
9464         /* if statement is already set then the label is defined twice,
9465          * otherwise it was just mentioned in a goto/local label declaration so far
9466          */
9467         if (label->statement != NULL) {
9468                 errorf(HERE, "duplicate label '%Y' (declared %P)", label->base.symbol, &label->base.source_position);
9469         } else {
9470                 label->base.source_position = token.source_position;
9471                 label->statement            = statement;
9472         }
9473
9474         eat(':');
9475
9476         statement->label.statement = parse_label_inner_statement(statement, "label");
9477
9478         /* remember the labels in a list for later checking */
9479         *label_anchor = &statement->label;
9480         label_anchor  = &statement->label.next;
9481
9482         POP_PARENT;
9483         return statement;
9484 }
9485
9486 /**
9487  * Parse an if statement.
9488  */
9489 static statement_t *parse_if(void)
9490 {
9491         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9492
9493         eat(T_if);
9494
9495         PUSH_PARENT(statement);
9496
9497         add_anchor_token('{');
9498
9499         expect('(', end_error);
9500         add_anchor_token(')');
9501         expression_t *const expr = parse_expression();
9502         statement->ifs.condition = expr;
9503         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9504          *             scalar type. */
9505         semantic_condition(expr, "condition of 'if'-statment");
9506         mark_vars_read(expr, NULL);
9507         rem_anchor_token(')');
9508         expect(')', end_error);
9509
9510 end_error:
9511         rem_anchor_token('{');
9512
9513         add_anchor_token(T_else);
9514         statement_t *const true_stmt = parse_statement();
9515         statement->ifs.true_statement = true_stmt;
9516         rem_anchor_token(T_else);
9517
9518         if (next_if(T_else)) {
9519                 statement->ifs.false_statement = parse_statement();
9520         } else if (warning.parentheses &&
9521                         true_stmt->kind == STATEMENT_IF &&
9522                         true_stmt->ifs.false_statement != NULL) {
9523                 warningf(&true_stmt->base.source_position,
9524                                 "suggest explicit braces to avoid ambiguous 'else'");
9525         }
9526
9527         POP_PARENT;
9528         return statement;
9529 }
9530
9531 /**
9532  * Check that all enums are handled in a switch.
9533  *
9534  * @param statement  the switch statement to check
9535  */
9536 static void check_enum_cases(const switch_statement_t *statement)
9537 {
9538         const type_t *type = skip_typeref(statement->expression->base.type);
9539         if (! is_type_enum(type))
9540                 return;
9541         const enum_type_t *enumt = &type->enumt;
9542
9543         /* if we have a default, no warnings */
9544         if (statement->default_label != NULL)
9545                 return;
9546
9547         /* FIXME: calculation of value should be done while parsing */
9548         /* TODO: quadratic algorithm here. Change to an n log n one */
9549         long            last_value = -1;
9550         const entity_t *entry      = enumt->enume->base.next;
9551         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9552              entry = entry->base.next) {
9553                 const expression_t *expression = entry->enum_value.value;
9554                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9555                 bool                found      = false;
9556                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9557                         if (l->expression == NULL)
9558                                 continue;
9559                         if (l->first_case <= value && value <= l->last_case) {
9560                                 found = true;
9561                                 break;
9562                         }
9563                 }
9564                 if (! found) {
9565                         warningf(&statement->base.source_position,
9566                                  "enumeration value '%Y' not handled in switch",
9567                                  entry->base.symbol);
9568                 }
9569                 last_value = value;
9570         }
9571 }
9572
9573 /**
9574  * Parse a switch statement.
9575  */
9576 static statement_t *parse_switch(void)
9577 {
9578         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9579
9580         eat(T_switch);
9581
9582         PUSH_PARENT(statement);
9583
9584         expect('(', end_error);
9585         add_anchor_token(')');
9586         expression_t *const expr = parse_expression();
9587         mark_vars_read(expr, NULL);
9588         type_t       *      type = skip_typeref(expr->base.type);
9589         if (is_type_integer(type)) {
9590                 type = promote_integer(type);
9591                 if (warning.traditional) {
9592                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9593                                 warningf(&expr->base.source_position,
9594                                         "'%T' switch expression not converted to '%T' in ISO C",
9595                                         type, type_int);
9596                         }
9597                 }
9598         } else if (is_type_valid(type)) {
9599                 errorf(&expr->base.source_position,
9600                        "switch quantity is not an integer, but '%T'", type);
9601                 type = type_error_type;
9602         }
9603         statement->switchs.expression = create_implicit_cast(expr, type);
9604         expect(')', end_error);
9605         rem_anchor_token(')');
9606
9607         switch_statement_t *rem = current_switch;
9608         current_switch          = &statement->switchs;
9609         statement->switchs.body = parse_statement();
9610         current_switch          = rem;
9611
9612         if (warning.switch_default &&
9613             statement->switchs.default_label == NULL) {
9614                 warningf(&statement->base.source_position, "switch has no default case");
9615         }
9616         if (warning.switch_enum)
9617                 check_enum_cases(&statement->switchs);
9618
9619         POP_PARENT;
9620         return statement;
9621 end_error:
9622         POP_PARENT;
9623         return create_invalid_statement();
9624 }
9625
9626 static statement_t *parse_loop_body(statement_t *const loop)
9627 {
9628         statement_t *const rem = current_loop;
9629         current_loop = loop;
9630
9631         statement_t *const body = parse_statement();
9632
9633         current_loop = rem;
9634         return body;
9635 }
9636
9637 /**
9638  * Parse a while statement.
9639  */
9640 static statement_t *parse_while(void)
9641 {
9642         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9643
9644         eat(T_while);
9645
9646         PUSH_PARENT(statement);
9647
9648         expect('(', end_error);
9649         add_anchor_token(')');
9650         expression_t *const cond = parse_expression();
9651         statement->whiles.condition = cond;
9652         /* §6.8.5:2    The controlling expression of an iteration statement shall
9653          *             have scalar type. */
9654         semantic_condition(cond, "condition of 'while'-statement");
9655         mark_vars_read(cond, NULL);
9656         rem_anchor_token(')');
9657         expect(')', end_error);
9658
9659         statement->whiles.body = parse_loop_body(statement);
9660
9661         POP_PARENT;
9662         return statement;
9663 end_error:
9664         POP_PARENT;
9665         return create_invalid_statement();
9666 }
9667
9668 /**
9669  * Parse a do statement.
9670  */
9671 static statement_t *parse_do(void)
9672 {
9673         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9674
9675         eat(T_do);
9676
9677         PUSH_PARENT(statement);
9678
9679         add_anchor_token(T_while);
9680         statement->do_while.body = parse_loop_body(statement);
9681         rem_anchor_token(T_while);
9682
9683         expect(T_while, end_error);
9684         expect('(', end_error);
9685         add_anchor_token(')');
9686         expression_t *const cond = parse_expression();
9687         statement->do_while.condition = cond;
9688         /* §6.8.5:2    The controlling expression of an iteration statement shall
9689          *             have scalar type. */
9690         semantic_condition(cond, "condition of 'do-while'-statement");
9691         mark_vars_read(cond, NULL);
9692         rem_anchor_token(')');
9693         expect(')', end_error);
9694         expect(';', end_error);
9695
9696         POP_PARENT;
9697         return statement;
9698 end_error:
9699         POP_PARENT;
9700         return create_invalid_statement();
9701 }
9702
9703 /**
9704  * Parse a for statement.
9705  */
9706 static statement_t *parse_for(void)
9707 {
9708         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9709
9710         eat(T_for);
9711
9712         expect('(', end_error1);
9713         add_anchor_token(')');
9714
9715         PUSH_PARENT(statement);
9716
9717         size_t const  top       = environment_top();
9718         scope_t      *old_scope = scope_push(&statement->fors.scope);
9719
9720         bool old_gcc_extension = in_gcc_extension;
9721         while (next_if(T___extension__)) {
9722                 in_gcc_extension = true;
9723         }
9724
9725         if (next_if(';')) {
9726         } else if (is_declaration_specifier(&token, false)) {
9727                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9728         } else {
9729                 add_anchor_token(';');
9730                 expression_t *const init = parse_expression();
9731                 statement->fors.initialisation = init;
9732                 mark_vars_read(init, ENT_ANY);
9733                 if (warning.unused_value && !expression_has_effect(init)) {
9734                         warningf(&init->base.source_position,
9735                                         "initialisation of 'for'-statement has no effect");
9736                 }
9737                 rem_anchor_token(';');
9738                 expect(';', end_error2);
9739         }
9740         in_gcc_extension = old_gcc_extension;
9741
9742         if (token.type != ';') {
9743                 add_anchor_token(';');
9744                 expression_t *const cond = parse_expression();
9745                 statement->fors.condition = cond;
9746                 /* §6.8.5:2    The controlling expression of an iteration statement
9747                  *             shall have scalar type. */
9748                 semantic_condition(cond, "condition of 'for'-statement");
9749                 mark_vars_read(cond, NULL);
9750                 rem_anchor_token(';');
9751         }
9752         expect(';', end_error2);
9753         if (token.type != ')') {
9754                 expression_t *const step = parse_expression();
9755                 statement->fors.step = step;
9756                 mark_vars_read(step, ENT_ANY);
9757                 if (warning.unused_value && !expression_has_effect(step)) {
9758                         warningf(&step->base.source_position,
9759                                  "step of 'for'-statement has no effect");
9760                 }
9761         }
9762         expect(')', end_error2);
9763         rem_anchor_token(')');
9764         statement->fors.body = parse_loop_body(statement);
9765
9766         assert(current_scope == &statement->fors.scope);
9767         scope_pop(old_scope);
9768         environment_pop_to(top);
9769
9770         POP_PARENT;
9771         return statement;
9772
9773 end_error2:
9774         POP_PARENT;
9775         rem_anchor_token(')');
9776         assert(current_scope == &statement->fors.scope);
9777         scope_pop(old_scope);
9778         environment_pop_to(top);
9779         /* fallthrough */
9780
9781 end_error1:
9782         return create_invalid_statement();
9783 }
9784
9785 /**
9786  * Parse a goto statement.
9787  */
9788 static statement_t *parse_goto(void)
9789 {
9790         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9791         eat(T_goto);
9792
9793         if (GNU_MODE && next_if('*')) {
9794                 expression_t *expression = parse_expression();
9795                 mark_vars_read(expression, NULL);
9796
9797                 /* Argh: although documentation says the expression must be of type void*,
9798                  * gcc accepts anything that can be casted into void* without error */
9799                 type_t *type = expression->base.type;
9800
9801                 if (type != type_error_type) {
9802                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9803                                 errorf(&expression->base.source_position,
9804                                         "cannot convert to a pointer type");
9805                         } else if (warning.other && type != type_void_ptr) {
9806                                 warningf(&expression->base.source_position,
9807                                         "type of computed goto expression should be 'void*' not '%T'", type);
9808                         }
9809                         expression = create_implicit_cast(expression, type_void_ptr);
9810                 }
9811
9812                 statement->gotos.expression = expression;
9813         } else if (token.type == T_IDENTIFIER) {
9814                 statement->gotos.label = get_label();
9815         } else {
9816                 if (GNU_MODE)
9817                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9818                 else
9819                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9820                 eat_until_anchor();
9821                 return create_invalid_statement();
9822         }
9823
9824         /* remember the goto's in a list for later checking */
9825         *goto_anchor = &statement->gotos;
9826         goto_anchor  = &statement->gotos.next;
9827
9828         expect(';', end_error);
9829
9830 end_error:
9831         return statement;
9832 }
9833
9834 /**
9835  * Parse a continue statement.
9836  */
9837 static statement_t *parse_continue(void)
9838 {
9839         if (current_loop == NULL) {
9840                 errorf(HERE, "continue statement not within loop");
9841         }
9842
9843         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9844
9845         eat(T_continue);
9846         expect(';', end_error);
9847
9848 end_error:
9849         return statement;
9850 }
9851
9852 /**
9853  * Parse a break statement.
9854  */
9855 static statement_t *parse_break(void)
9856 {
9857         if (current_switch == NULL && current_loop == NULL) {
9858                 errorf(HERE, "break statement not within loop or switch");
9859         }
9860
9861         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9862
9863         eat(T_break);
9864         expect(';', end_error);
9865
9866 end_error:
9867         return statement;
9868 }
9869
9870 /**
9871  * Parse a __leave statement.
9872  */
9873 static statement_t *parse_leave_statement(void)
9874 {
9875         if (current_try == NULL) {
9876                 errorf(HERE, "__leave statement not within __try");
9877         }
9878
9879         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9880
9881         eat(T___leave);
9882         expect(';', end_error);
9883
9884 end_error:
9885         return statement;
9886 }
9887
9888 /**
9889  * Check if a given entity represents a local variable.
9890  */
9891 static bool is_local_variable(const entity_t *entity)
9892 {
9893         if (entity->kind != ENTITY_VARIABLE)
9894                 return false;
9895
9896         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9897         case STORAGE_CLASS_AUTO:
9898         case STORAGE_CLASS_REGISTER: {
9899                 const type_t *type = skip_typeref(entity->declaration.type);
9900                 if (is_type_function(type)) {
9901                         return false;
9902                 } else {
9903                         return true;
9904                 }
9905         }
9906         default:
9907                 return false;
9908         }
9909 }
9910
9911 /**
9912  * Check if a given expression represents a local variable.
9913  */
9914 static bool expression_is_local_variable(const expression_t *expression)
9915 {
9916         if (expression->base.kind != EXPR_REFERENCE) {
9917                 return false;
9918         }
9919         const entity_t *entity = expression->reference.entity;
9920         return is_local_variable(entity);
9921 }
9922
9923 /**
9924  * Check if a given expression represents a local variable and
9925  * return its declaration then, else return NULL.
9926  */
9927 entity_t *expression_is_variable(const expression_t *expression)
9928 {
9929         if (expression->base.kind != EXPR_REFERENCE) {
9930                 return NULL;
9931         }
9932         entity_t *entity = expression->reference.entity;
9933         if (entity->kind != ENTITY_VARIABLE)
9934                 return NULL;
9935
9936         return entity;
9937 }
9938
9939 /**
9940  * Parse a return statement.
9941  */
9942 static statement_t *parse_return(void)
9943 {
9944         eat(T_return);
9945
9946         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9947
9948         expression_t *return_value = NULL;
9949         if (token.type != ';') {
9950                 return_value = parse_expression();
9951                 mark_vars_read(return_value, NULL);
9952         }
9953
9954         const type_t *const func_type = skip_typeref(current_function->base.type);
9955         assert(is_type_function(func_type));
9956         type_t *const return_type = skip_typeref(func_type->function.return_type);
9957
9958         source_position_t const *const pos = &statement->base.source_position;
9959         if (return_value != NULL) {
9960                 type_t *return_value_type = skip_typeref(return_value->base.type);
9961
9962                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9963                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9964                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9965                                 /* Only warn in C mode, because GCC does the same */
9966                                 if (c_mode & _CXX || strict_mode) {
9967                                         errorf(pos,
9968                                                         "'return' with a value, in function returning 'void'");
9969                                 } else if (warning.other) {
9970                                         warningf(pos,
9971                                                         "'return' with a value, in function returning 'void'");
9972                                 }
9973                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9974                                 /* Only warn in C mode, because GCC does the same */
9975                                 if (strict_mode) {
9976                                         errorf(pos,
9977                                                         "'return' with expression in function returning 'void'");
9978                                 } else if (warning.other) {
9979                                         warningf(pos,
9980                                                         "'return' with expression in function returning 'void'");
9981                                 }
9982                         }
9983                 } else {
9984                         assign_error_t error = semantic_assign(return_type, return_value);
9985                         report_assign_error(error, return_type, return_value, "'return'",
9986                                             pos);
9987                 }
9988                 return_value = create_implicit_cast(return_value, return_type);
9989                 /* check for returning address of a local var */
9990                 if (warning.other && return_value != NULL
9991                     && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9992                         const expression_t *expression = return_value->unary.value;
9993                         if (expression_is_local_variable(expression)) {
9994                                 warningf(pos, "function returns address of local variable");
9995                         }
9996                 }
9997         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9998                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9999                 if (c_mode & _CXX || strict_mode) {
10000                         errorf(pos,
10001                                "'return' without value, in function returning non-void");
10002                 } else {
10003                         warningf(pos,
10004                                  "'return' without value, in function returning non-void");
10005                 }
10006         }
10007         statement->returns.value = return_value;
10008
10009         expect(';', end_error);
10010
10011 end_error:
10012         return statement;
10013 }
10014
10015 /**
10016  * Parse a declaration statement.
10017  */
10018 static statement_t *parse_declaration_statement(void)
10019 {
10020         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10021
10022         entity_t *before = current_scope->last_entity;
10023         if (GNU_MODE) {
10024                 parse_external_declaration();
10025         } else {
10026                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10027         }
10028
10029         declaration_statement_t *const decl  = &statement->declaration;
10030         entity_t                *const begin =
10031                 before != NULL ? before->base.next : current_scope->entities;
10032         decl->declarations_begin = begin;
10033         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10034
10035         return statement;
10036 }
10037
10038 /**
10039  * Parse an expression statement, ie. expr ';'.
10040  */
10041 static statement_t *parse_expression_statement(void)
10042 {
10043         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10044
10045         expression_t *const expr         = parse_expression();
10046         statement->expression.expression = expr;
10047         mark_vars_read(expr, ENT_ANY);
10048
10049         expect(';', end_error);
10050
10051 end_error:
10052         return statement;
10053 }
10054
10055 /**
10056  * Parse a microsoft __try { } __finally { } or
10057  * __try{ } __except() { }
10058  */
10059 static statement_t *parse_ms_try_statment(void)
10060 {
10061         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10062         eat(T___try);
10063
10064         PUSH_PARENT(statement);
10065
10066         ms_try_statement_t *rem = current_try;
10067         current_try = &statement->ms_try;
10068         statement->ms_try.try_statement = parse_compound_statement(false);
10069         current_try = rem;
10070
10071         POP_PARENT;
10072
10073         if (next_if(T___except)) {
10074                 expect('(', end_error);
10075                 add_anchor_token(')');
10076                 expression_t *const expr = parse_expression();
10077                 mark_vars_read(expr, NULL);
10078                 type_t       *      type = skip_typeref(expr->base.type);
10079                 if (is_type_integer(type)) {
10080                         type = promote_integer(type);
10081                 } else if (is_type_valid(type)) {
10082                         errorf(&expr->base.source_position,
10083                                "__expect expression is not an integer, but '%T'", type);
10084                         type = type_error_type;
10085                 }
10086                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10087                 rem_anchor_token(')');
10088                 expect(')', end_error);
10089                 statement->ms_try.final_statement = parse_compound_statement(false);
10090         } else if (next_if(T__finally)) {
10091                 statement->ms_try.final_statement = parse_compound_statement(false);
10092         } else {
10093                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10094                 return create_invalid_statement();
10095         }
10096         return statement;
10097 end_error:
10098         return create_invalid_statement();
10099 }
10100
10101 static statement_t *parse_empty_statement(void)
10102 {
10103         if (warning.empty_statement) {
10104                 warningf(HERE, "statement is empty");
10105         }
10106         statement_t *const statement = create_empty_statement();
10107         eat(';');
10108         return statement;
10109 }
10110
10111 static statement_t *parse_local_label_declaration(void)
10112 {
10113         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10114
10115         eat(T___label__);
10116
10117         entity_t *begin   = NULL;
10118         entity_t *end     = NULL;
10119         entity_t **anchor = &begin;
10120         do {
10121                 if (token.type != T_IDENTIFIER) {
10122                         parse_error_expected("while parsing local label declaration",
10123                                 T_IDENTIFIER, NULL);
10124                         goto end_error;
10125                 }
10126                 symbol_t *symbol = token.symbol;
10127                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10128                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10129                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10130                                symbol, &entity->base.source_position);
10131                 } else {
10132                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol);
10133                         entity->base.parent_scope    = current_scope;
10134                         entity->base.source_position = token.source_position;
10135
10136                         *anchor = entity;
10137                         anchor  = &entity->base.next;
10138                         end     = entity;
10139
10140                         environment_push(entity);
10141                 }
10142                 next_token();
10143         } while (next_if(','));
10144         expect(';', end_error);
10145 end_error:
10146         statement->declaration.declarations_begin = begin;
10147         statement->declaration.declarations_end   = end;
10148         return statement;
10149 }
10150
10151 static void parse_namespace_definition(void)
10152 {
10153         eat(T_namespace);
10154
10155         entity_t *entity = NULL;
10156         symbol_t *symbol = NULL;
10157
10158         if (token.type == T_IDENTIFIER) {
10159                 symbol = token.symbol;
10160                 next_token();
10161
10162                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10163                 if (entity != NULL
10164                                 && entity->kind != ENTITY_NAMESPACE
10165                                 && entity->base.parent_scope == current_scope) {
10166                         if (is_entity_valid(entity)) {
10167                                 error_redefined_as_different_kind(&token.source_position,
10168                                                 entity, ENTITY_NAMESPACE);
10169                         }
10170                         entity = NULL;
10171                 }
10172         }
10173
10174         if (entity == NULL) {
10175                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol);
10176                 entity->base.source_position = token.source_position;
10177                 entity->base.parent_scope    = current_scope;
10178         }
10179
10180         if (token.type == '=') {
10181                 /* TODO: parse namespace alias */
10182                 panic("namespace alias definition not supported yet");
10183         }
10184
10185         environment_push(entity);
10186         append_entity(current_scope, entity);
10187
10188         size_t const  top       = environment_top();
10189         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10190
10191         entity_t     *old_current_entity = current_entity;
10192         current_entity = entity;
10193
10194         expect('{', end_error);
10195         parse_externals();
10196         expect('}', end_error);
10197
10198 end_error:
10199         assert(current_scope == &entity->namespacee.members);
10200         assert(current_entity == entity);
10201         current_entity = old_current_entity;
10202         scope_pop(old_scope);
10203         environment_pop_to(top);
10204 }
10205
10206 /**
10207  * Parse a statement.
10208  * There's also parse_statement() which additionally checks for
10209  * "statement has no effect" warnings
10210  */
10211 static statement_t *intern_parse_statement(void)
10212 {
10213         statement_t *statement = NULL;
10214
10215         /* declaration or statement */
10216         add_anchor_token(';');
10217         switch (token.type) {
10218         case T_IDENTIFIER: {
10219                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10220                 if (la1_type == ':') {
10221                         statement = parse_label_statement();
10222                 } else if (is_typedef_symbol(token.symbol)) {
10223                         statement = parse_declaration_statement();
10224                 } else {
10225                         /* it's an identifier, the grammar says this must be an
10226                          * expression statement. However it is common that users mistype
10227                          * declaration types, so we guess a bit here to improve robustness
10228                          * for incorrect programs */
10229                         switch (la1_type) {
10230                         case '&':
10231                         case '*':
10232                                 if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL) {
10233                         default:
10234                                         statement = parse_expression_statement();
10235                                 } else {
10236                         DECLARATION_START
10237                         case T_IDENTIFIER:
10238                                         statement = parse_declaration_statement();
10239                                 }
10240                                 break;
10241                         }
10242                 }
10243                 break;
10244         }
10245
10246         case T___extension__:
10247                 /* This can be a prefix to a declaration or an expression statement.
10248                  * We simply eat it now and parse the rest with tail recursion. */
10249                 while (next_if(T___extension__)) {}
10250                 bool old_gcc_extension = in_gcc_extension;
10251                 in_gcc_extension       = true;
10252                 statement = intern_parse_statement();
10253                 in_gcc_extension = old_gcc_extension;
10254                 break;
10255
10256         DECLARATION_START
10257                 statement = parse_declaration_statement();
10258                 break;
10259
10260         case T___label__:
10261                 statement = parse_local_label_declaration();
10262                 break;
10263
10264         case ';':         statement = parse_empty_statement();         break;
10265         case '{':         statement = parse_compound_statement(false); break;
10266         case T___leave:   statement = parse_leave_statement();         break;
10267         case T___try:     statement = parse_ms_try_statment();         break;
10268         case T_asm:       statement = parse_asm_statement();           break;
10269         case T_break:     statement = parse_break();                   break;
10270         case T_case:      statement = parse_case_statement();          break;
10271         case T_continue:  statement = parse_continue();                break;
10272         case T_default:   statement = parse_default_statement();       break;
10273         case T_do:        statement = parse_do();                      break;
10274         case T_for:       statement = parse_for();                     break;
10275         case T_goto:      statement = parse_goto();                    break;
10276         case T_if:        statement = parse_if();                      break;
10277         case T_return:    statement = parse_return();                  break;
10278         case T_switch:    statement = parse_switch();                  break;
10279         case T_while:     statement = parse_while();                   break;
10280
10281         EXPRESSION_START
10282                 statement = parse_expression_statement();
10283                 break;
10284
10285         default:
10286                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10287                 statement = create_invalid_statement();
10288                 if (!at_anchor())
10289                         next_token();
10290                 break;
10291         }
10292         rem_anchor_token(';');
10293
10294         assert(statement != NULL
10295                         && statement->base.source_position.input_name != NULL);
10296
10297         return statement;
10298 }
10299
10300 /**
10301  * parse a statement and emits "statement has no effect" warning if needed
10302  * (This is really a wrapper around intern_parse_statement with check for 1
10303  *  single warning. It is needed, because for statement expressions we have
10304  *  to avoid the warning on the last statement)
10305  */
10306 static statement_t *parse_statement(void)
10307 {
10308         statement_t *statement = intern_parse_statement();
10309
10310         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10311                 expression_t *expression = statement->expression.expression;
10312                 if (!expression_has_effect(expression)) {
10313                         warningf(&expression->base.source_position,
10314                                         "statement has no effect");
10315                 }
10316         }
10317
10318         return statement;
10319 }
10320
10321 /**
10322  * Parse a compound statement.
10323  */
10324 static statement_t *parse_compound_statement(bool inside_expression_statement)
10325 {
10326         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10327
10328         PUSH_PARENT(statement);
10329
10330         eat('{');
10331         add_anchor_token('}');
10332         /* tokens, which can start a statement */
10333         /* TODO MS, __builtin_FOO */
10334         add_anchor_token('!');
10335         add_anchor_token('&');
10336         add_anchor_token('(');
10337         add_anchor_token('*');
10338         add_anchor_token('+');
10339         add_anchor_token('-');
10340         add_anchor_token('{');
10341         add_anchor_token('~');
10342         add_anchor_token(T_CHARACTER_CONSTANT);
10343         add_anchor_token(T_COLONCOLON);
10344         add_anchor_token(T_FLOATINGPOINT);
10345         add_anchor_token(T_IDENTIFIER);
10346         add_anchor_token(T_INTEGER);
10347         add_anchor_token(T_MINUSMINUS);
10348         add_anchor_token(T_PLUSPLUS);
10349         add_anchor_token(T_STRING_LITERAL);
10350         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10351         add_anchor_token(T_WIDE_STRING_LITERAL);
10352         add_anchor_token(T__Bool);
10353         add_anchor_token(T__Complex);
10354         add_anchor_token(T__Imaginary);
10355         add_anchor_token(T___FUNCTION__);
10356         add_anchor_token(T___PRETTY_FUNCTION__);
10357         add_anchor_token(T___alignof__);
10358         add_anchor_token(T___attribute__);
10359         add_anchor_token(T___builtin_va_start);
10360         add_anchor_token(T___extension__);
10361         add_anchor_token(T___func__);
10362         add_anchor_token(T___imag__);
10363         add_anchor_token(T___label__);
10364         add_anchor_token(T___real__);
10365         add_anchor_token(T___thread);
10366         add_anchor_token(T_asm);
10367         add_anchor_token(T_auto);
10368         add_anchor_token(T_bool);
10369         add_anchor_token(T_break);
10370         add_anchor_token(T_case);
10371         add_anchor_token(T_char);
10372         add_anchor_token(T_class);
10373         add_anchor_token(T_const);
10374         add_anchor_token(T_const_cast);
10375         add_anchor_token(T_continue);
10376         add_anchor_token(T_default);
10377         add_anchor_token(T_delete);
10378         add_anchor_token(T_double);
10379         add_anchor_token(T_do);
10380         add_anchor_token(T_dynamic_cast);
10381         add_anchor_token(T_enum);
10382         add_anchor_token(T_extern);
10383         add_anchor_token(T_false);
10384         add_anchor_token(T_float);
10385         add_anchor_token(T_for);
10386         add_anchor_token(T_goto);
10387         add_anchor_token(T_if);
10388         add_anchor_token(T_inline);
10389         add_anchor_token(T_int);
10390         add_anchor_token(T_long);
10391         add_anchor_token(T_new);
10392         add_anchor_token(T_operator);
10393         add_anchor_token(T_register);
10394         add_anchor_token(T_reinterpret_cast);
10395         add_anchor_token(T_restrict);
10396         add_anchor_token(T_return);
10397         add_anchor_token(T_short);
10398         add_anchor_token(T_signed);
10399         add_anchor_token(T_sizeof);
10400         add_anchor_token(T_static);
10401         add_anchor_token(T_static_cast);
10402         add_anchor_token(T_struct);
10403         add_anchor_token(T_switch);
10404         add_anchor_token(T_template);
10405         add_anchor_token(T_this);
10406         add_anchor_token(T_throw);
10407         add_anchor_token(T_true);
10408         add_anchor_token(T_try);
10409         add_anchor_token(T_typedef);
10410         add_anchor_token(T_typeid);
10411         add_anchor_token(T_typename);
10412         add_anchor_token(T_typeof);
10413         add_anchor_token(T_union);
10414         add_anchor_token(T_unsigned);
10415         add_anchor_token(T_using);
10416         add_anchor_token(T_void);
10417         add_anchor_token(T_volatile);
10418         add_anchor_token(T_wchar_t);
10419         add_anchor_token(T_while);
10420
10421         size_t const  top       = environment_top();
10422         scope_t      *old_scope = scope_push(&statement->compound.scope);
10423
10424         statement_t **anchor            = &statement->compound.statements;
10425         bool          only_decls_so_far = true;
10426         while (token.type != '}') {
10427                 if (token.type == T_EOF) {
10428                         errorf(&statement->base.source_position,
10429                                "EOF while parsing compound statement");
10430                         break;
10431                 }
10432                 statement_t *sub_statement = intern_parse_statement();
10433                 if (is_invalid_statement(sub_statement)) {
10434                         /* an error occurred. if we are at an anchor, return */
10435                         if (at_anchor())
10436                                 goto end_error;
10437                         continue;
10438                 }
10439
10440                 if (warning.declaration_after_statement) {
10441                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10442                                 only_decls_so_far = false;
10443                         } else if (!only_decls_so_far) {
10444                                 warningf(&sub_statement->base.source_position,
10445                                          "ISO C90 forbids mixed declarations and code");
10446                         }
10447                 }
10448
10449                 *anchor = sub_statement;
10450
10451                 while (sub_statement->base.next != NULL)
10452                         sub_statement = sub_statement->base.next;
10453
10454                 anchor = &sub_statement->base.next;
10455         }
10456         next_token();
10457
10458         /* look over all statements again to produce no effect warnings */
10459         if (warning.unused_value) {
10460                 statement_t *sub_statement = statement->compound.statements;
10461                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10462                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10463                                 continue;
10464                         /* don't emit a warning for the last expression in an expression
10465                          * statement as it has always an effect */
10466                         if (inside_expression_statement && sub_statement->base.next == NULL)
10467                                 continue;
10468
10469                         expression_t *expression = sub_statement->expression.expression;
10470                         if (!expression_has_effect(expression)) {
10471                                 warningf(&expression->base.source_position,
10472                                          "statement has no effect");
10473                         }
10474                 }
10475         }
10476
10477 end_error:
10478         rem_anchor_token(T_while);
10479         rem_anchor_token(T_wchar_t);
10480         rem_anchor_token(T_volatile);
10481         rem_anchor_token(T_void);
10482         rem_anchor_token(T_using);
10483         rem_anchor_token(T_unsigned);
10484         rem_anchor_token(T_union);
10485         rem_anchor_token(T_typeof);
10486         rem_anchor_token(T_typename);
10487         rem_anchor_token(T_typeid);
10488         rem_anchor_token(T_typedef);
10489         rem_anchor_token(T_try);
10490         rem_anchor_token(T_true);
10491         rem_anchor_token(T_throw);
10492         rem_anchor_token(T_this);
10493         rem_anchor_token(T_template);
10494         rem_anchor_token(T_switch);
10495         rem_anchor_token(T_struct);
10496         rem_anchor_token(T_static_cast);
10497         rem_anchor_token(T_static);
10498         rem_anchor_token(T_sizeof);
10499         rem_anchor_token(T_signed);
10500         rem_anchor_token(T_short);
10501         rem_anchor_token(T_return);
10502         rem_anchor_token(T_restrict);
10503         rem_anchor_token(T_reinterpret_cast);
10504         rem_anchor_token(T_register);
10505         rem_anchor_token(T_operator);
10506         rem_anchor_token(T_new);
10507         rem_anchor_token(T_long);
10508         rem_anchor_token(T_int);
10509         rem_anchor_token(T_inline);
10510         rem_anchor_token(T_if);
10511         rem_anchor_token(T_goto);
10512         rem_anchor_token(T_for);
10513         rem_anchor_token(T_float);
10514         rem_anchor_token(T_false);
10515         rem_anchor_token(T_extern);
10516         rem_anchor_token(T_enum);
10517         rem_anchor_token(T_dynamic_cast);
10518         rem_anchor_token(T_do);
10519         rem_anchor_token(T_double);
10520         rem_anchor_token(T_delete);
10521         rem_anchor_token(T_default);
10522         rem_anchor_token(T_continue);
10523         rem_anchor_token(T_const_cast);
10524         rem_anchor_token(T_const);
10525         rem_anchor_token(T_class);
10526         rem_anchor_token(T_char);
10527         rem_anchor_token(T_case);
10528         rem_anchor_token(T_break);
10529         rem_anchor_token(T_bool);
10530         rem_anchor_token(T_auto);
10531         rem_anchor_token(T_asm);
10532         rem_anchor_token(T___thread);
10533         rem_anchor_token(T___real__);
10534         rem_anchor_token(T___label__);
10535         rem_anchor_token(T___imag__);
10536         rem_anchor_token(T___func__);
10537         rem_anchor_token(T___extension__);
10538         rem_anchor_token(T___builtin_va_start);
10539         rem_anchor_token(T___attribute__);
10540         rem_anchor_token(T___alignof__);
10541         rem_anchor_token(T___PRETTY_FUNCTION__);
10542         rem_anchor_token(T___FUNCTION__);
10543         rem_anchor_token(T__Imaginary);
10544         rem_anchor_token(T__Complex);
10545         rem_anchor_token(T__Bool);
10546         rem_anchor_token(T_WIDE_STRING_LITERAL);
10547         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10548         rem_anchor_token(T_STRING_LITERAL);
10549         rem_anchor_token(T_PLUSPLUS);
10550         rem_anchor_token(T_MINUSMINUS);
10551         rem_anchor_token(T_INTEGER);
10552         rem_anchor_token(T_IDENTIFIER);
10553         rem_anchor_token(T_FLOATINGPOINT);
10554         rem_anchor_token(T_COLONCOLON);
10555         rem_anchor_token(T_CHARACTER_CONSTANT);
10556         rem_anchor_token('~');
10557         rem_anchor_token('{');
10558         rem_anchor_token('-');
10559         rem_anchor_token('+');
10560         rem_anchor_token('*');
10561         rem_anchor_token('(');
10562         rem_anchor_token('&');
10563         rem_anchor_token('!');
10564         rem_anchor_token('}');
10565         assert(current_scope == &statement->compound.scope);
10566         scope_pop(old_scope);
10567         environment_pop_to(top);
10568
10569         POP_PARENT;
10570         return statement;
10571 }
10572
10573 /**
10574  * Check for unused global static functions and variables
10575  */
10576 static void check_unused_globals(void)
10577 {
10578         if (!warning.unused_function && !warning.unused_variable)
10579                 return;
10580
10581         for (const entity_t *entity = file_scope->entities; entity != NULL;
10582              entity = entity->base.next) {
10583                 if (!is_declaration(entity))
10584                         continue;
10585
10586                 const declaration_t *declaration = &entity->declaration;
10587                 if (declaration->used                  ||
10588                     declaration->modifiers & DM_UNUSED ||
10589                     declaration->modifiers & DM_USED   ||
10590                     declaration->storage_class != STORAGE_CLASS_STATIC)
10591                         continue;
10592
10593                 type_t *const type = declaration->type;
10594                 const char *s;
10595                 if (entity->kind == ENTITY_FUNCTION) {
10596                         /* inhibit warning for static inline functions */
10597                         if (entity->function.is_inline)
10598                                 continue;
10599
10600                         s = entity->function.statement != NULL ? "defined" : "declared";
10601                 } else {
10602                         s = "defined";
10603                 }
10604
10605                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10606                         type, declaration->base.symbol, s);
10607         }
10608 }
10609
10610 static void parse_global_asm(void)
10611 {
10612         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10613
10614         eat(T_asm);
10615         expect('(', end_error);
10616
10617         statement->asms.asm_text = parse_string_literals();
10618         statement->base.next     = unit->global_asm;
10619         unit->global_asm         = statement;
10620
10621         expect(')', end_error);
10622         expect(';', end_error);
10623
10624 end_error:;
10625 }
10626
10627 static void parse_linkage_specification(void)
10628 {
10629         eat(T_extern);
10630
10631         const char *linkage = parse_string_literals().begin;
10632
10633         linkage_kind_t old_linkage = current_linkage;
10634         linkage_kind_t new_linkage;
10635         if (strcmp(linkage, "C") == 0) {
10636                 new_linkage = LINKAGE_C;
10637         } else if (strcmp(linkage, "C++") == 0) {
10638                 new_linkage = LINKAGE_CXX;
10639         } else {
10640                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10641                 new_linkage = LINKAGE_INVALID;
10642         }
10643         current_linkage = new_linkage;
10644
10645         if (next_if('{')) {
10646                 parse_externals();
10647                 expect('}', end_error);
10648         } else {
10649                 parse_external();
10650         }
10651
10652 end_error:
10653         assert(current_linkage == new_linkage);
10654         current_linkage = old_linkage;
10655 }
10656
10657 static void parse_external(void)
10658 {
10659         switch (token.type) {
10660                 DECLARATION_START_NO_EXTERN
10661                 case T_IDENTIFIER:
10662                 case T___extension__:
10663                 /* tokens below are for implicit int */
10664                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10665                              implicit int) */
10666                 case '*': /* * x; -> int* x; */
10667                 case '(': /* (x); -> int (x); */
10668                         parse_external_declaration();
10669                         return;
10670
10671                 case T_extern:
10672                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10673                                 parse_linkage_specification();
10674                         } else {
10675                                 parse_external_declaration();
10676                         }
10677                         return;
10678
10679                 case T_asm:
10680                         parse_global_asm();
10681                         return;
10682
10683                 case T_namespace:
10684                         parse_namespace_definition();
10685                         return;
10686
10687                 case ';':
10688                         if (!strict_mode) {
10689                                 if (warning.other)
10690                                         warningf(HERE, "stray ';' outside of function");
10691                                 next_token();
10692                                 return;
10693                         }
10694                         /* FALLTHROUGH */
10695
10696                 default:
10697                         errorf(HERE, "stray %K outside of function", &token);
10698                         if (token.type == '(' || token.type == '{' || token.type == '[')
10699                                 eat_until_matching_token(token.type);
10700                         next_token();
10701                         return;
10702         }
10703 }
10704
10705 static void parse_externals(void)
10706 {
10707         add_anchor_token('}');
10708         add_anchor_token(T_EOF);
10709
10710 #ifndef NDEBUG
10711         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10712         unsigned char token_anchor_copy[T_LAST_TOKEN];
10713         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10714 #endif
10715
10716         while (token.type != T_EOF && token.type != '}') {
10717 #ifndef NDEBUG
10718                 bool anchor_leak = false;
10719                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10720                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10721                         if (count != 0) {
10722                                 /* the anchor set and its copy differs */
10723                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10724                                 anchor_leak = true;
10725                         }
10726                 }
10727                 if (in_gcc_extension) {
10728                         /* an gcc extension scope was not closed */
10729                         internal_errorf(HERE, "Leaked __extension__");
10730                         anchor_leak = true;
10731                 }
10732
10733                 if (anchor_leak)
10734                         abort();
10735 #endif
10736
10737                 parse_external();
10738         }
10739
10740         rem_anchor_token(T_EOF);
10741         rem_anchor_token('}');
10742 }
10743
10744 /**
10745  * Parse a translation unit.
10746  */
10747 static void parse_translation_unit(void)
10748 {
10749         add_anchor_token(T_EOF);
10750
10751         while (true) {
10752                 parse_externals();
10753
10754                 if (token.type == T_EOF)
10755                         break;
10756
10757                 errorf(HERE, "stray %K outside of function", &token);
10758                 if (token.type == '(' || token.type == '{' || token.type == '[')
10759                         eat_until_matching_token(token.type);
10760                 next_token();
10761         }
10762 }
10763
10764 void set_default_visibility(elf_visibility_tag_t visibility)
10765 {
10766         default_visibility = visibility;
10767 }
10768
10769 /**
10770  * Parse the input.
10771  *
10772  * @return  the translation unit or NULL if errors occurred.
10773  */
10774 void start_parsing(void)
10775 {
10776         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10777         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10778         diagnostic_count  = 0;
10779         error_count       = 0;
10780         warning_count     = 0;
10781
10782         print_to_file(stderr);
10783
10784         assert(unit == NULL);
10785         unit = allocate_ast_zero(sizeof(unit[0]));
10786
10787         assert(file_scope == NULL);
10788         file_scope = &unit->scope;
10789
10790         assert(current_scope == NULL);
10791         scope_push(&unit->scope);
10792
10793         create_gnu_builtins();
10794         if (c_mode & _MS)
10795                 create_microsoft_intrinsics();
10796 }
10797
10798 translation_unit_t *finish_parsing(void)
10799 {
10800         assert(current_scope == &unit->scope);
10801         scope_pop(NULL);
10802
10803         assert(file_scope == &unit->scope);
10804         check_unused_globals();
10805         file_scope = NULL;
10806
10807         DEL_ARR_F(environment_stack);
10808         DEL_ARR_F(label_stack);
10809
10810         translation_unit_t *result = unit;
10811         unit = NULL;
10812         return result;
10813 }
10814
10815 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10816  * are given length one. */
10817 static void complete_incomplete_arrays(void)
10818 {
10819         size_t n = ARR_LEN(incomplete_arrays);
10820         for (size_t i = 0; i != n; ++i) {
10821                 declaration_t *const decl      = incomplete_arrays[i];
10822                 type_t        *const orig_type = decl->type;
10823                 type_t        *const type      = skip_typeref(orig_type);
10824
10825                 if (!is_type_incomplete(type))
10826                         continue;
10827
10828                 if (warning.other) {
10829                         warningf(&decl->base.source_position,
10830                                         "array '%#T' assumed to have one element",
10831                                         orig_type, decl->base.symbol);
10832                 }
10833
10834                 type_t *const new_type = duplicate_type(type);
10835                 new_type->array.size_constant     = true;
10836                 new_type->array.has_implicit_size = true;
10837                 new_type->array.size              = 1;
10838
10839                 type_t *const result = identify_new_type(new_type);
10840
10841                 decl->type = result;
10842         }
10843 }
10844
10845 void prepare_main_collect2(entity_t *entity)
10846 {
10847         // create call to __main
10848         symbol_t *symbol         = symbol_table_insert("__main");
10849         entity_t *subsubmain_ent
10850                 = create_implicit_function(symbol, &builtin_source_position);
10851
10852         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10853         type_t       *ftype       = subsubmain_ent->declaration.type;
10854         ref->base.source_position = builtin_source_position;
10855         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10856         ref->reference.entity     = subsubmain_ent;
10857
10858         expression_t *call = allocate_expression_zero(EXPR_CALL);
10859         call->base.source_position = builtin_source_position;
10860         call->base.type            = type_void;
10861         call->call.function        = ref;
10862
10863         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10864         expr_statement->base.source_position  = builtin_source_position;
10865         expr_statement->expression.expression = call;
10866
10867         statement_t *statement = entity->function.statement;
10868         assert(statement->kind == STATEMENT_COMPOUND);
10869         compound_statement_t *compounds = &statement->compound;
10870
10871         expr_statement->base.next = compounds->statements;
10872         compounds->statements     = expr_statement;
10873 }
10874
10875 void parse(void)
10876 {
10877         lookahead_bufpos = 0;
10878         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10879                 next_token();
10880         }
10881         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10882         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10883         parse_translation_unit();
10884         complete_incomplete_arrays();
10885         DEL_ARR_F(incomplete_arrays);
10886         incomplete_arrays = NULL;
10887 }
10888
10889 /**
10890  * Initialize the parser.
10891  */
10892 void init_parser(void)
10893 {
10894         sym_anonymous = symbol_table_insert("<anonymous>");
10895
10896         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10897
10898         init_expression_parsers();
10899         obstack_init(&temp_obst);
10900 }
10901
10902 /**
10903  * Terminate the parser.
10904  */
10905 void exit_parser(void)
10906 {
10907         obstack_free(&temp_obst, NULL);
10908 }