nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "attribute_t.h"
  38 #include "lang_features.h"
  39 #include "walk_statements.h"
  40 #include "warning.h"
  41 #include "printer.h"
  42 #include "adt/bitfiddle.h"
  43 #include "adt/error.h"
  44 #include "adt/array.h"
  45
  46 //#define PRINT_TOKENS
  47 #define MAX_LOOKAHEAD 1
  48
  49 typedef struct {
  50         entity_t           *old_entity;
  51         symbol_t           *symbol;
  52         entity_namespace_t  namespc;
  53 } stack_entry_t;
  54
  55 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  56 struct declaration_specifiers_t {
  57         source_position_t  source_position;
  58         storage_class_t    storage_class;
  59         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  60         bool               is_inline    : 1;
  61         bool               thread_local : 1;  /**< GCC __thread */
  62         attribute_t       *attributes;        /**< list of attributes */
  63         type_t            *type;
  64 };
  65
  66 /**
  67  * An environment for parsing initializers (and compound literals).
  68  */
  69 typedef struct parse_initializer_env_t {
  70         type_t     *type;   /**< the type of the initializer. In case of an
  71                                  array type with unspecified size this gets
  72                                  adjusted to the actual size. */
  73         entity_t   *entity; /**< the variable that is initialized if any */
  74         bool        must_be_constant;
  75 } parse_initializer_env_t;
  76
  77 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  78
  79 /** The current token. */
  80 static token_t              token;
  81 /** The lookahead ring-buffer. */
  82 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  83 /** Position of the next token in the lookahead buffer. */
  84 static size_t               lookahead_bufpos;
  85 static stack_entry_t       *environment_stack = NULL;
  86 static stack_entry_t       *label_stack       = NULL;
  87 static scope_t             *file_scope        = NULL;
  88 static scope_t             *current_scope     = NULL;
  89 /** Point to the current function declaration if inside a function. */
  90 static function_t          *current_function  = NULL;
  91 static entity_t            *current_entity    = NULL;
  92 static entity_t            *current_init_decl = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in a type property context (evaluation only for type) */
 105 static bool                 in_type_prop      = false;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_PARENT(stmt)                          \
 115         statement_t *const prev_parent = current_parent; \
 116         ((void)(current_parent = (stmt)))
 117 #define POP_PARENT ((void)(current_parent = prev_parent))
 118
 119 /** special symbol used for anonymous entities. */
 120 static symbol_t *sym_anonymous = NULL;
 121
 122 /** The token anchor set */
 123 static unsigned char token_anchor_set[T_LAST_TOKEN];
 124
 125 /** The current source position. */
 126 #define HERE (&token.source_position)
 127
 128 /** true if we are in GCC mode. */
 129 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 130
 131 static statement_t *parse_compound_statement(bool inside_expression_statement);
 132 static statement_t *parse_statement(void);
 133
 134 static expression_t *parse_subexpression(precedence_t);
 135 static expression_t *parse_expression(void);
 136 static type_t       *parse_typename(void);
 137 static void          parse_externals(void);
 138 static void          parse_external(void);
 139
 140 static void parse_compound_type_entries(compound_t *compound_declaration);
 141
 142 static void check_call_argument(type_t          *expected_type,
 143                                                                 call_argument_t *argument, unsigned pos);
 144
 145 typedef enum declarator_flags_t {
 146         DECL_FLAGS_NONE             = 0,
 147         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 148         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 149         DECL_IS_PARAMETER           = 1U << 2
 150 } declarator_flags_t;
 151
 152 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 153                                   declarator_flags_t flags);
 154
 155 static void semantic_comparison(binary_expression_t *expression);
 156
 157 #define STORAGE_CLASSES       \
 158         STORAGE_CLASSES_NO_EXTERN \
 159         case T_extern:
 160
 161 #define STORAGE_CLASSES_NO_EXTERN \
 162         case T_typedef:         \
 163         case T_static:          \
 164         case T_auto:            \
 165         case T_register:        \
 166         case T___thread:
 167
 168 #define TYPE_QUALIFIERS     \
 169         case T_const:           \
 170         case T_restrict:        \
 171         case T_volatile:        \
 172         case T_inline:          \
 173         case T__forceinline:    \
 174         case T___attribute__:
 175
 176 #define COMPLEX_SPECIFIERS  \
 177         case T__Complex:
 178 #define IMAGINARY_SPECIFIERS \
 179         case T__Imaginary:
 180
 181 #define TYPE_SPECIFIERS       \
 182         case T__Bool:             \
 183         case T___builtin_va_list: \
 184         case T___typeof__:        \
 185         case T__declspec:         \
 186         case T_bool:              \
 187         case T_char:              \
 188         case T_double:            \
 189         case T_enum:              \
 190         case T_float:             \
 191         case T_int:               \
 192         case T_long:              \
 193         case T_short:             \
 194         case T_signed:            \
 195         case T_struct:            \
 196         case T_union:             \
 197         case T_unsigned:          \
 198         case T_void:              \
 199         case T_wchar_t:           \
 200         case T__int8:             \
 201         case T__int16:            \
 202         case T__int32:            \
 203         case T__int64:            \
 204         case T__int128:           \
 205         COMPLEX_SPECIFIERS        \
 206         IMAGINARY_SPECIFIERS
 207
 208 #define DECLARATION_START   \
 209         STORAGE_CLASSES         \
 210         TYPE_QUALIFIERS         \
 211         TYPE_SPECIFIERS
 212
 213 #define DECLARATION_START_NO_EXTERN \
 214         STORAGE_CLASSES_NO_EXTERN       \
 215         TYPE_QUALIFIERS                 \
 216         TYPE_SPECIFIERS
 217
 218 #define EXPRESSION_START              \
 219         case '!':                         \
 220         case '&':                         \
 221         case '(':                         \
 222         case '*':                         \
 223         case '+':                         \
 224         case '-':                         \
 225         case '~':                         \
 226         case T_ANDAND:                    \
 227         case T_CHARACTER_CONSTANT:        \
 228         case T_FLOATINGPOINT:             \
 229         case T_FLOATINGPOINT_HEXADECIMAL: \
 230         case T_INTEGER:                   \
 231         case T_INTEGER_HEXADECIMAL:       \
 232         case T_INTEGER_OCTAL:             \
 233         case T_MINUSMINUS:                \
 234         case T_PLUSPLUS:                  \
 235         case T_STRING_LITERAL:            \
 236         case T_WIDE_CHARACTER_CONSTANT:   \
 237         case T_WIDE_STRING_LITERAL:       \
 238         case T___FUNCDNAME__:             \
 239         case T___FUNCSIG__:               \
 240         case T___FUNCTION__:              \
 241         case T___PRETTY_FUNCTION__:       \
 242         case T___alignof__:               \
 243         case T___builtin_classify_type:   \
 244         case T___builtin_constant_p:      \
 245         case T___builtin_isgreater:       \
 246         case T___builtin_isgreaterequal:  \
 247         case T___builtin_isless:          \
 248         case T___builtin_islessequal:     \
 249         case T___builtin_islessgreater:   \
 250         case T___builtin_isunordered:     \
 251         case T___builtin_offsetof:        \
 252         case T___builtin_va_arg:          \
 253         case T___builtin_va_copy:         \
 254         case T___builtin_va_start:        \
 255         case T___func__:                  \
 256         case T___noop:                    \
 257         case T__assume:                   \
 258         case T_delete:                    \
 259         case T_false:                     \
 260         case T_sizeof:                    \
 261         case T_throw:                     \
 262         case T_true:
 263
 264 /**
 265  * Returns the size of a statement node.
 266  *
 267  * @param kind  the statement kind
 268  */
 269 static size_t get_statement_struct_size(statement_kind_t kind)
 270 {
 271         static const size_t sizes[] = {
 272                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 273                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 274                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 275                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 276                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 277                 [STATEMENT_IF]          = sizeof(if_statement_t),
 278                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 279                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 280                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 281                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 282                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 283                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 284                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 285                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 286                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 287                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 288                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 289                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 290                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 291         };
 292         assert((size_t)kind < lengthof(sizes));
 293         assert(sizes[kind] != 0);
 294         return sizes[kind];
 295 }
 296
 297 /**
 298  * Returns the size of an expression node.
 299  *
 300  * @param kind  the expression kind
 301  */
 302 static size_t get_expression_struct_size(expression_kind_t kind)
 303 {
 304         static const size_t sizes[] = {
 305                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 306                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 307                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 308                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 309                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 310                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 311                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 312                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 313                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 314                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 315                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 316                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 317                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 318                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 319                 [EXPR_CALL]                       = sizeof(call_expression_t),
 320                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 321                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 322                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 323                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 324                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 325                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 326                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 327                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 328                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 329                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 330                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 331                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 332                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 333                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 334                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 335                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 336                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 337         };
 338         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 339                 return sizes[EXPR_UNARY_FIRST];
 340         }
 341         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 342                 return sizes[EXPR_BINARY_FIRST];
 343         }
 344         assert((size_t)kind < lengthof(sizes));
 345         assert(sizes[kind] != 0);
 346         return sizes[kind];
 347 }
 348
 349 /**
 350  * Allocate a statement node of given kind and initialize all
 351  * fields with zero. Sets its source position to the position
 352  * of the current token.
 353  */
 354 static statement_t *allocate_statement_zero(statement_kind_t kind)
 355 {
 356         size_t       size = get_statement_struct_size(kind);
 357         statement_t *res  = allocate_ast_zero(size);
 358
 359         res->base.kind            = kind;
 360         res->base.parent          = current_parent;
 361         res->base.source_position = token.source_position;
 362         return res;
 363 }
 364
 365 /**
 366  * Allocate an expression node of given kind and initialize all
 367  * fields with zero.
 368  *
 369  * @param kind  the kind of the expression to allocate
 370  */
 371 static expression_t *allocate_expression_zero(expression_kind_t kind)
 372 {
 373         size_t        size = get_expression_struct_size(kind);
 374         expression_t *res  = allocate_ast_zero(size);
 375
 376         res->base.kind            = kind;
 377         res->base.type            = type_error_type;
 378         res->base.source_position = token.source_position;
 379         return res;
 380 }
 381
 382 /**
 383  * Creates a new invalid expression at the source position
 384  * of the current token.
 385  */
 386 static expression_t *create_invalid_expression(void)
 387 {
 388         return allocate_expression_zero(EXPR_INVALID);
 389 }
 390
 391 /**
 392  * Creates a new invalid statement.
 393  */
 394 static statement_t *create_invalid_statement(void)
 395 {
 396         return allocate_statement_zero(STATEMENT_INVALID);
 397 }
 398
 399 /**
 400  * Allocate a new empty statement.
 401  */
 402 static statement_t *create_empty_statement(void)
 403 {
 404         return allocate_statement_zero(STATEMENT_EMPTY);
 405 }
 406
 407 static function_parameter_t *allocate_parameter(type_t *const type)
 408 {
 409         function_parameter_t *const param
 410                 = obstack_alloc(type_obst, sizeof(*param));
 411         memset(param, 0, sizeof(*param));
 412         param->type = type;
 413         return param;
 414 }
 415
 416 /**
 417  * Returns the size of an initializer node.
 418  *
 419  * @param kind  the initializer kind
 420  */
 421 static size_t get_initializer_size(initializer_kind_t kind)
 422 {
 423         static const size_t sizes[] = {
 424                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 425                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 426                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 427                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 428                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 429         };
 430         assert((size_t)kind < lengthof(sizes));
 431         assert(sizes[kind] != 0);
 432         return sizes[kind];
 433 }
 434
 435 /**
 436  * Allocate an initializer node of given kind and initialize all
 437  * fields with zero.
 438  */
 439 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 440 {
 441         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 442         result->kind          = kind;
 443
 444         return result;
 445 }
 446
 447 /**
 448  * Returns the index of the top element of the environment stack.
 449  */
 450 static size_t environment_top(void)
 451 {
 452         return ARR_LEN(environment_stack);
 453 }
 454
 455 /**
 456  * Returns the index of the top element of the global label stack.
 457  */
 458 static size_t label_top(void)
 459 {
 460         return ARR_LEN(label_stack);
 461 }
 462
 463 /**
 464  * Return the next token.
 465  */
 466 static inline void next_token(void)
 467 {
 468         token                              = lookahead_buffer[lookahead_bufpos];
 469         lookahead_buffer[lookahead_bufpos] = lexer_token;
 470         lexer_next_token();
 471
 472         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 473
 474 #ifdef PRINT_TOKENS
 475         print_token(stderr, &token);
 476         fprintf(stderr, "\n");
 477 #endif
 478 }
 479
 480 static inline bool next_if(int const type)
 481 {
 482         if (token.type == type) {
 483                 next_token();
 484                 return true;
 485         } else {
 486                 return false;
 487         }
 488 }
 489
 490 /**
 491  * Return the next token with a given lookahead.
 492  */
 493 static inline const token_t *look_ahead(size_t num)
 494 {
 495         assert(0 < num && num <= MAX_LOOKAHEAD);
 496         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 497         return &lookahead_buffer[pos];
 498 }
 499
 500 /**
 501  * Adds a token type to the token type anchor set (a multi-set).
 502  */
 503 static void add_anchor_token(int token_type)
 504 {
 505         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 506         ++token_anchor_set[token_type];
 507 }
 508
 509 /**
 510  * Set the number of tokens types of the given type
 511  * to zero and return the old count.
 512  */
 513 static int save_and_reset_anchor_state(int token_type)
 514 {
 515         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 516         int count = token_anchor_set[token_type];
 517         token_anchor_set[token_type] = 0;
 518         return count;
 519 }
 520
 521 /**
 522  * Restore the number of token types to the given count.
 523  */
 524 static void restore_anchor_state(int token_type, int count)
 525 {
 526         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 527         token_anchor_set[token_type] = count;
 528 }
 529
 530 /**
 531  * Remove a token type from the token type anchor set (a multi-set).
 532  */
 533 static void rem_anchor_token(int token_type)
 534 {
 535         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 536         assert(token_anchor_set[token_type] != 0);
 537         --token_anchor_set[token_type];
 538 }
 539
 540 /**
 541  * Return true if the token type of the current token is
 542  * in the anchor set.
 543  */
 544 static bool at_anchor(void)
 545 {
 546         if (token.type < 0)
 547                 return false;
 548         return token_anchor_set[token.type];
 549 }
 550
 551 /**
 552  * Eat tokens until a matching token type is found.
 553  */
 554 static void eat_until_matching_token(int type)
 555 {
 556         int end_token;
 557         switch (type) {
 558                 case '(': end_token = ')';  break;
 559                 case '{': end_token = '}';  break;
 560                 case '[': end_token = ']';  break;
 561                 default:  end_token = type; break;
 562         }
 563
 564         unsigned parenthesis_count = 0;
 565         unsigned brace_count       = 0;
 566         unsigned bracket_count     = 0;
 567         while (token.type        != end_token ||
 568                parenthesis_count != 0         ||
 569                brace_count       != 0         ||
 570                bracket_count     != 0) {
 571                 switch (token.type) {
 572                 case T_EOF: return;
 573                 case '(': ++parenthesis_count; break;
 574                 case '{': ++brace_count;       break;
 575                 case '[': ++bracket_count;     break;
 576
 577                 case ')':
 578                         if (parenthesis_count > 0)
 579                                 --parenthesis_count;
 580                         goto check_stop;
 581
 582                 case '}':
 583                         if (brace_count > 0)
 584                                 --brace_count;
 585                         goto check_stop;
 586
 587                 case ']':
 588                         if (bracket_count > 0)
 589                                 --bracket_count;
 590 check_stop:
 591                         if (token.type        == end_token &&
 592                             parenthesis_count == 0         &&
 593                             brace_count       == 0         &&
 594                             bracket_count     == 0)
 595                                 return;
 596                         break;
 597
 598                 default:
 599                         break;
 600                 }
 601                 next_token();
 602         }
 603 }
 604
 605 /**
 606  * Eat input tokens until an anchor is found.
 607  */
 608 static void eat_until_anchor(void)
 609 {
 610         while (token_anchor_set[token.type] == 0) {
 611                 if (token.type == '(' || token.type == '{' || token.type == '[')
 612                         eat_until_matching_token(token.type);
 613                 next_token();
 614         }
 615 }
 616
 617 /**
 618  * Eat a whole block from input tokens.
 619  */
 620 static void eat_block(void)
 621 {
 622         eat_until_matching_token('{');
 623         next_if('}');
 624 }
 625
 626 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 627
 628 /**
 629  * Report a parse error because an expected token was not found.
 630  */
 631 static
 632 #if defined __GNUC__ && __GNUC__ >= 4
 633 __attribute__((sentinel))
 634 #endif
 635 void parse_error_expected(const char *message, ...)
 636 {
 637         if (message != NULL) {
 638                 errorf(HERE, "%s", message);
 639         }
 640         va_list ap;
 641         va_start(ap, message);
 642         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 643         va_end(ap);
 644 }
 645
 646 /**
 647  * Report an incompatible type.
 648  */
 649 static void type_error_incompatible(const char *msg,
 650                 const source_position_t *source_position, type_t *type1, type_t *type2)
 651 {
 652         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 653                msg, type1, type2);
 654 }
 655
 656 /**
 657  * Expect the current token is the expected token.
 658  * If not, generate an error, eat the current statement,
 659  * and goto the error_label label.
 660  */
 661 #define expect(expected, error_label)                     \
 662         do {                                                  \
 663                 if (UNLIKELY(token.type != (expected))) {         \
 664                         parse_error_expected(NULL, (expected), NULL); \
 665                         add_anchor_token(expected);                   \
 666                         eat_until_anchor();                           \
 667                         next_if((expected));                          \
 668                         rem_anchor_token(expected);                   \
 669                         goto error_label;                             \
 670                 }                                                 \
 671                 next_token();                                     \
 672         } while (0)
 673
 674 /**
 675  * Push a given scope on the scope stack and make it the
 676  * current scope
 677  */
 678 static scope_t *scope_push(scope_t *new_scope)
 679 {
 680         if (current_scope != NULL) {
 681                 new_scope->depth = current_scope->depth + 1;
 682         }
 683
 684         scope_t *old_scope = current_scope;
 685         current_scope      = new_scope;
 686         return old_scope;
 687 }
 688
 689 /**
 690  * Pop the current scope from the scope stack.
 691  */
 692 static void scope_pop(scope_t *old_scope)
 693 {
 694         current_scope = old_scope;
 695 }
 696
 697 /**
 698  * Search an entity by its symbol in a given namespace.
 699  */
 700 static entity_t *get_entity(const symbol_t *const symbol,
 701                             namespace_tag_t namespc)
 702 {
 703         assert(namespc != NAMESPACE_INVALID);
 704         entity_t *entity = symbol->entity;
 705         for (; entity != NULL; entity = entity->base.symbol_next) {
 706                 if ((namespace_tag_t)entity->base.namespc == namespc)
 707                         return entity;
 708         }
 709
 710         return NULL;
 711 }
 712
 713 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 714  * possible. */
 715 static entity_t *get_tag(symbol_t const *const symbol,
 716                          entity_kind_tag_t const kind)
 717 {
 718         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 719         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 720                 errorf(HERE,
 721                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 722                                 symbol, &entity->base.source_position);
 723                 entity = NULL;
 724         }
 725         return entity;
 726 }
 727
 728 /**
 729  * pushs an entity on the environment stack and links the corresponding symbol
 730  * it.
 731  */
 732 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 733 {
 734         symbol_t           *symbol  = entity->base.symbol;
 735         entity_namespace_t  namespc = entity->base.namespc;
 736         assert(namespc != NAMESPACE_INVALID);
 737
 738         /* replace/add entity into entity list of the symbol */
 739         entity_t **anchor;
 740         entity_t  *iter;
 741         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 742                 iter = *anchor;
 743                 if (iter == NULL)
 744                         break;
 745
 746                 /* replace an entry? */
 747                 if (iter->base.namespc == namespc) {
 748                         entity->base.symbol_next = iter->base.symbol_next;
 749                         break;
 750                 }
 751         }
 752         *anchor = entity;
 753
 754         /* remember old declaration */
 755         stack_entry_t entry;
 756         entry.symbol     = symbol;
 757         entry.old_entity = iter;
 758         entry.namespc    = namespc;
 759         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 760 }
 761
 762 /**
 763  * Push an entity on the environment stack.
 764  */
 765 static void environment_push(entity_t *entity)
 766 {
 767         assert(entity->base.source_position.input_name != NULL);
 768         assert(entity->base.parent_scope != NULL);
 769         stack_push(&environment_stack, entity);
 770 }
 771
 772 /**
 773  * Push a declaration on the global label stack.
 774  *
 775  * @param declaration  the declaration
 776  */
 777 static void label_push(entity_t *label)
 778 {
 779         /* we abuse the parameters scope as parent for the labels */
 780         label->base.parent_scope = &current_function->parameters;
 781         stack_push(&label_stack, label);
 782 }
 783
 784 /**
 785  * pops symbols from the environment stack until @p new_top is the top element
 786  */
 787 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 788 {
 789         stack_entry_t *stack = *stack_ptr;
 790         size_t         top   = ARR_LEN(stack);
 791         size_t         i;
 792
 793         assert(new_top <= top);
 794         if (new_top == top)
 795                 return;
 796
 797         for (i = top; i > new_top; --i) {
 798                 stack_entry_t *entry = &stack[i - 1];
 799
 800                 entity_t           *old_entity = entry->old_entity;
 801                 symbol_t           *symbol     = entry->symbol;
 802                 entity_namespace_t  namespc    = entry->namespc;
 803
 804                 /* replace with old_entity/remove */
 805                 entity_t **anchor;
 806                 entity_t  *iter;
 807                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 808                         iter = *anchor;
 809                         assert(iter != NULL);
 810                         /* replace an entry? */
 811                         if (iter->base.namespc == namespc)
 812                                 break;
 813                 }
 814
 815                 /* restore definition from outer scopes (if there was one) */
 816                 if (old_entity != NULL) {
 817                         old_entity->base.symbol_next = iter->base.symbol_next;
 818                         *anchor                      = old_entity;
 819                 } else {
 820                         /* remove entry from list */
 821                         *anchor = iter->base.symbol_next;
 822                 }
 823         }
 824
 825         ARR_SHRINKLEN(*stack_ptr, new_top);
 826 }
 827
 828 /**
 829  * Pop all entries from the environment stack until the new_top
 830  * is reached.
 831  *
 832  * @param new_top  the new stack top
 833  */
 834 static void environment_pop_to(size_t new_top)
 835 {
 836         stack_pop_to(&environment_stack, new_top);
 837 }
 838
 839 /**
 840  * Pop all entries from the global label stack until the new_top
 841  * is reached.
 842  *
 843  * @param new_top  the new stack top
 844  */
 845 static void label_pop_to(size_t new_top)
 846 {
 847         stack_pop_to(&label_stack, new_top);
 848 }
 849
 850 static int get_akind_rank(atomic_type_kind_t akind)
 851 {
 852         return (int) akind;
 853 }
 854
 855 /**
 856  * Return the type rank for an atomic type.
 857  */
 858 static int get_rank(const type_t *type)
 859 {
 860         assert(!is_typeref(type));
 861         if (type->kind == TYPE_ENUM)
 862                 return get_akind_rank(type->enumt.akind);
 863
 864         assert(type->kind == TYPE_ATOMIC);
 865         return get_akind_rank(type->atomic.akind);
 866 }
 867
 868 /**
 869  * §6.3.1.1:2  Do integer promotion for a given type.
 870  *
 871  * @param type  the type to promote
 872  * @return the promoted type
 873  */
 874 static type_t *promote_integer(type_t *type)
 875 {
 876         if (type->kind == TYPE_BITFIELD)
 877                 type = type->bitfield.base_type;
 878
 879         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 880                 type = type_int;
 881
 882         return type;
 883 }
 884
 885 /**
 886  * Create a cast expression.
 887  *
 888  * @param expression  the expression to cast
 889  * @param dest_type   the destination type
 890  */
 891 static expression_t *create_cast_expression(expression_t *expression,
 892                                             type_t *dest_type)
 893 {
 894         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 895
 896         cast->unary.value = expression;
 897         cast->base.type   = dest_type;
 898
 899         return cast;
 900 }
 901
 902 /**
 903  * Check if a given expression represents a null pointer constant.
 904  *
 905  * @param expression  the expression to check
 906  */
 907 static bool is_null_pointer_constant(const expression_t *expression)
 908 {
 909         /* skip void* cast */
 910         if (expression->kind == EXPR_UNARY_CAST ||
 911                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 912                 type_t *const type = skip_typeref(expression->base.type);
 913                 if (types_compatible(type, type_void_ptr))
 914                         expression = expression->unary.value;
 915         }
 916
 917         type_t *const type = skip_typeref(expression->base.type);
 918         if (!is_type_integer(type))
 919                 return false;
 920         switch (is_constant_expression(expression)) {
 921                 case EXPR_CLASS_ERROR:    return true;
 922                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 923                 default:                  return false;
 924         }
 925 }
 926
 927 /**
 928  * Create an implicit cast expression.
 929  *
 930  * @param expression  the expression to cast
 931  * @param dest_type   the destination type
 932  */
 933 static expression_t *create_implicit_cast(expression_t *expression,
 934                                           type_t *dest_type)
 935 {
 936         type_t *const source_type = expression->base.type;
 937
 938         if (source_type == dest_type)
 939                 return expression;
 940
 941         return create_cast_expression(expression, dest_type);
 942 }
 943
 944 typedef enum assign_error_t {
 945         ASSIGN_SUCCESS,
 946         ASSIGN_ERROR_INCOMPATIBLE,
 947         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 948         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 949         ASSIGN_WARNING_POINTER_FROM_INT,
 950         ASSIGN_WARNING_INT_FROM_POINTER
 951 } assign_error_t;
 952
 953 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
 954                                 const expression_t *const right,
 955                                 const char *context,
 956                                 const source_position_t *source_position)
 957 {
 958         type_t *const orig_type_right = right->base.type;
 959         type_t *const type_left       = skip_typeref(orig_type_left);
 960         type_t *const type_right      = skip_typeref(orig_type_right);
 961
 962         switch (error) {
 963         case ASSIGN_SUCCESS:
 964                 return;
 965         case ASSIGN_ERROR_INCOMPATIBLE:
 966                 errorf(source_position,
 967                        "destination type '%T' in %s is incompatible with type '%T'",
 968                        orig_type_left, context, orig_type_right);
 969                 return;
 970
 971         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 972                 if (warning.other) {
 973                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 974                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 975
 976                         /* the left type has all qualifiers from the right type */
 977                         unsigned missing_qualifiers
 978                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 979                         warningf(source_position,
 980                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
 981                                         orig_type_left, context, orig_type_right, missing_qualifiers);
 982                 }
 983                 return;
 984         }
 985
 986         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 987                 if (warning.other) {
 988                         warningf(source_position,
 989                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 990                                         orig_type_left, context, right, orig_type_right);
 991                 }
 992                 return;
 993
 994         case ASSIGN_WARNING_POINTER_FROM_INT:
 995                 if (warning.other) {
 996                         warningf(source_position,
 997                                         "%s makes pointer '%T' from integer '%T' without a cast",
 998                                         context, orig_type_left, orig_type_right);
 999                 }
1000                 return;
1001
1002         case ASSIGN_WARNING_INT_FROM_POINTER:
1003                 if (warning.other) {
1004                         warningf(source_position,
1005                                         "%s makes integer '%T' from pointer '%T' without a cast",
1006                                         context, orig_type_left, orig_type_right);
1007                 }
1008                 return;
1009
1010         default:
1011                 panic("invalid error value");
1012         }
1013 }
1014
1015 /** Implements the rules from §6.5.16.1 */
1016 static assign_error_t semantic_assign(type_t *orig_type_left,
1017                                       const expression_t *const right)
1018 {
1019         type_t *const orig_type_right = right->base.type;
1020         type_t *const type_left       = skip_typeref(orig_type_left);
1021         type_t *const type_right      = skip_typeref(orig_type_right);
1022
1023         if (is_type_pointer(type_left)) {
1024                 if (is_null_pointer_constant(right)) {
1025                         return ASSIGN_SUCCESS;
1026                 } else if (is_type_pointer(type_right)) {
1027                         type_t *points_to_left
1028                                 = skip_typeref(type_left->pointer.points_to);
1029                         type_t *points_to_right
1030                                 = skip_typeref(type_right->pointer.points_to);
1031                         assign_error_t res = ASSIGN_SUCCESS;
1032
1033                         /* the left type has all qualifiers from the right type */
1034                         unsigned missing_qualifiers
1035                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1036                         if (missing_qualifiers != 0) {
1037                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1038                         }
1039
1040                         points_to_left  = get_unqualified_type(points_to_left);
1041                         points_to_right = get_unqualified_type(points_to_right);
1042
1043                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1044                                 return res;
1045
1046                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1047                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1048                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1049                         }
1050
1051                         if (!types_compatible(points_to_left, points_to_right)) {
1052                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1053                         }
1054
1055                         return res;
1056                 } else if (is_type_integer(type_right)) {
1057                         return ASSIGN_WARNING_POINTER_FROM_INT;
1058                 }
1059         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1060                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1061                                 && is_type_pointer(type_right))) {
1062                 return ASSIGN_SUCCESS;
1063         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1064                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1065                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1066                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1067                         return ASSIGN_SUCCESS;
1068                 }
1069         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1070                 return ASSIGN_WARNING_INT_FROM_POINTER;
1071         }
1072
1073         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1074                 return ASSIGN_SUCCESS;
1075
1076         return ASSIGN_ERROR_INCOMPATIBLE;
1077 }
1078
1079 static expression_t *parse_constant_expression(void)
1080 {
1081         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1082
1083         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1084                 errorf(&result->base.source_position,
1085                        "expression '%E' is not constant", result);
1086         }
1087
1088         return result;
1089 }
1090
1091 static expression_t *parse_assignment_expression(void)
1092 {
1093         return parse_subexpression(PREC_ASSIGNMENT);
1094 }
1095
1096 static void warn_string_concat(const source_position_t *pos)
1097 {
1098         if (warning.traditional) {
1099                 warningf(pos, "traditional C rejects string constant concatenation");
1100         }
1101 }
1102
1103 static string_t parse_string_literals(void)
1104 {
1105         assert(token.type == T_STRING_LITERAL);
1106         string_t result = token.literal;
1107
1108         next_token();
1109
1110         while (token.type == T_STRING_LITERAL) {
1111                 warn_string_concat(&token.source_position);
1112                 result = concat_strings(&result, &token.literal);
1113                 next_token();
1114         }
1115
1116         return result;
1117 }
1118
1119 /**
1120  * compare two string, ignoring double underscores on the second.
1121  */
1122 static int strcmp_underscore(const char *s1, const char *s2)
1123 {
1124         if (s2[0] == '_' && s2[1] == '_') {
1125                 size_t len2 = strlen(s2);
1126                 size_t len1 = strlen(s1);
1127                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1128                         return strncmp(s1, s2+2, len2-4);
1129                 }
1130         }
1131
1132         return strcmp(s1, s2);
1133 }
1134
1135 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1136 {
1137         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1138         attribute->kind        = kind;
1139         return attribute;
1140 }
1141
1142 /**
1143  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1144  *
1145  *  attribute:
1146  *    __attribute__ ( ( attribute-list ) )
1147  *
1148  *  attribute-list:
1149  *    attrib
1150  *    attribute_list , attrib
1151  *
1152  *  attrib:
1153  *    empty
1154  *    any-word
1155  *    any-word ( identifier )
1156  *    any-word ( identifier , nonempty-expr-list )
1157  *    any-word ( expr-list )
1158  *
1159  *  where the "identifier" must not be declared as a type, and
1160  *  "any-word" may be any identifier (including one declared as a
1161  *  type), a reserved word storage class specifier, type specifier or
1162  *  type qualifier.  ??? This still leaves out most reserved keywords
1163  *  (following the old parser), shouldn't we include them, and why not
1164  *  allow identifiers declared as types to start the arguments?
1165  *
1166  *  Matze: this all looks confusing and little systematic, so we're even less
1167  *  strict and parse any list of things which are identifiers or
1168  *  (assignment-)expressions.
1169  */
1170 static attribute_argument_t *parse_attribute_arguments(void)
1171 {
1172         attribute_argument_t  *first  = NULL;
1173         attribute_argument_t **anchor = &first;
1174         if (token.type != ')') do {
1175                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1176
1177                 /* is it an identifier */
1178                 if (token.type == T_IDENTIFIER
1179                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1180                         symbol_t *symbol   = token.symbol;
1181                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1182                         argument->v.symbol = symbol;
1183                         next_token();
1184                 } else {
1185                         /* must be an expression */
1186                         expression_t *expression = parse_assignment_expression();
1187
1188                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1189                         argument->v.expression = expression;
1190                 }
1191
1192                 /* append argument */
1193                 *anchor = argument;
1194                 anchor  = &argument->next;
1195         } while (next_if(','));
1196         expect(')', end_error);
1197
1198         return first;
1199
1200 end_error:
1201         /* TODO... */
1202         return first;
1203 }
1204
1205 static attribute_t *parse_attribute_asm(void)
1206 {
1207         eat(T_asm);
1208
1209         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1210
1211         expect('(', end_error);
1212         attribute->a.arguments = parse_attribute_arguments();
1213         return attribute;
1214
1215 end_error:
1216         return NULL;
1217 }
1218
1219 static symbol_t *get_symbol_from_token(void)
1220 {
1221         switch(token.type) {
1222         case T_IDENTIFIER:
1223                 return token.symbol;
1224         case T_auto:
1225         case T_char:
1226         case T_double:
1227         case T_enum:
1228         case T_extern:
1229         case T_float:
1230         case T_int:
1231         case T_long:
1232         case T_register:
1233         case T_short:
1234         case T_static:
1235         case T_struct:
1236         case T_union:
1237         case T_unsigned:
1238         case T_void:
1239         case T_bool:
1240         case T__Bool:
1241         case T_class:
1242         case T_explicit:
1243         case T_export:
1244         case T_wchar_t:
1245         case T_const:
1246         case T_signed:
1247         case T___real__:
1248         case T___imag__:
1249         case T_restrict:
1250         case T_volatile:
1251         case T_inline:
1252                 /* maybe we need more tokens ... add them on demand */
1253                 return get_token_symbol(&token);
1254         default:
1255                 return NULL;
1256         }
1257 }
1258
1259 static attribute_t *parse_attribute_gnu_single(void)
1260 {
1261         /* parse "any-word" */
1262         symbol_t *symbol = get_symbol_from_token();
1263         if (symbol == NULL) {
1264                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1265                 return NULL;
1266         }
1267
1268         attribute_kind_t  kind;
1269         char const *const name = symbol->string;
1270         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1271                 if (kind > ATTRIBUTE_GNU_LAST) {
1272                         if (warning.attribute) {
1273                                 warningf(HERE, "unknown attribute '%s' ignored", name);
1274                         }
1275                         /* TODO: we should still save the attribute in the list... */
1276                         kind = ATTRIBUTE_UNKNOWN;
1277                         break;
1278                 }
1279
1280                 const char *attribute_name = get_attribute_name(kind);
1281                 if (attribute_name != NULL
1282                                 && strcmp_underscore(attribute_name, name) == 0)
1283                         break;
1284         }
1285
1286         next_token();
1287
1288         attribute_t *attribute = allocate_attribute_zero(kind);
1289
1290         /* parse arguments */
1291         if (next_if('('))
1292                 attribute->a.arguments = parse_attribute_arguments();
1293
1294         return attribute;
1295 }
1296
1297 static attribute_t *parse_attribute_gnu(void)
1298 {
1299         attribute_t  *first  = NULL;
1300         attribute_t **anchor = &first;
1301
1302         eat(T___attribute__);
1303         expect('(', end_error);
1304         expect('(', end_error);
1305
1306         if (token.type != ')') do {
1307                 attribute_t *attribute = parse_attribute_gnu_single();
1308                 if (attribute == NULL)
1309                         goto end_error;
1310
1311                 *anchor = attribute;
1312                 anchor  = &attribute->next;
1313         } while (next_if(','));
1314         expect(')', end_error);
1315         expect(')', end_error);
1316
1317 end_error:
1318         return first;
1319 }
1320
1321 /** Parse attributes. */
1322 static attribute_t *parse_attributes(attribute_t *first)
1323 {
1324         attribute_t **anchor = &first;
1325         for (;;) {
1326                 while (*anchor != NULL)
1327                         anchor = &(*anchor)->next;
1328
1329                 attribute_t *attribute;
1330                 switch (token.type) {
1331                 case T___attribute__:
1332                         attribute = parse_attribute_gnu();
1333                         if (attribute == NULL)
1334                                 continue;
1335                         break;
1336
1337                 case T_asm:
1338                         attribute = parse_attribute_asm();
1339                         break;
1340
1341                 case T_cdecl:
1342                         next_token();
1343                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1344                         break;
1345
1346                 case T__fastcall:
1347                         next_token();
1348                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1349                         break;
1350
1351                 case T__forceinline:
1352                         next_token();
1353                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1354                         break;
1355
1356                 case T__stdcall:
1357                         next_token();
1358                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1359                         break;
1360
1361                 case T___thiscall:
1362                         /* TODO record modifier */
1363                         if (warning.other)
1364                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1365                         eat(T___thiscall);
1366                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1367                         break;
1368
1369                 default:
1370                         return first;
1371                 }
1372
1373                 *anchor = attribute;
1374                 anchor  = &attribute->next;
1375         }
1376 }
1377
1378 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1379
1380 static entity_t *determine_lhs_ent(expression_t *const expr,
1381                                    entity_t *lhs_ent)
1382 {
1383         switch (expr->kind) {
1384                 case EXPR_REFERENCE: {
1385                         entity_t *const entity = expr->reference.entity;
1386                         /* we should only find variables as lvalues... */
1387                         if (entity->base.kind != ENTITY_VARIABLE
1388                                         && entity->base.kind != ENTITY_PARAMETER)
1389                                 return NULL;
1390
1391                         return entity;
1392                 }
1393
1394                 case EXPR_ARRAY_ACCESS: {
1395                         expression_t *const ref = expr->array_access.array_ref;
1396                         entity_t     *      ent = NULL;
1397                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1398                                 ent     = determine_lhs_ent(ref, lhs_ent);
1399                                 lhs_ent = ent;
1400                         } else {
1401                                 mark_vars_read(expr->select.compound, lhs_ent);
1402                         }
1403                         mark_vars_read(expr->array_access.index, lhs_ent);
1404                         return ent;
1405                 }
1406
1407                 case EXPR_SELECT: {
1408                         if (is_type_compound(skip_typeref(expr->base.type))) {
1409                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1410                         } else {
1411                                 mark_vars_read(expr->select.compound, lhs_ent);
1412                                 return NULL;
1413                         }
1414                 }
1415
1416                 case EXPR_UNARY_DEREFERENCE: {
1417                         expression_t *const val = expr->unary.value;
1418                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1419                                 /* *&x is a NOP */
1420                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1421                         } else {
1422                                 mark_vars_read(val, NULL);
1423                                 return NULL;
1424                         }
1425                 }
1426
1427                 default:
1428                         mark_vars_read(expr, NULL);
1429                         return NULL;
1430         }
1431 }
1432
1433 #define ENT_ANY ((entity_t*)-1)
1434
1435 /**
1436  * Mark declarations, which are read.  This is used to detect variables, which
1437  * are never read.
1438  * Example:
1439  * x = x + 1;
1440  *   x is not marked as "read", because it is only read to calculate its own new
1441  *   value.
1442  *
1443  * x += y; y += x;
1444  *   x and y are not detected as "not read", because multiple variables are
1445  *   involved.
1446  */
1447 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1448 {
1449         switch (expr->kind) {
1450                 case EXPR_REFERENCE: {
1451                         entity_t *const entity = expr->reference.entity;
1452                         if (entity->kind != ENTITY_VARIABLE
1453                                         && entity->kind != ENTITY_PARAMETER)
1454                                 return;
1455
1456                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1457                                 if (entity->kind == ENTITY_VARIABLE) {
1458                                         entity->variable.read = true;
1459                                 } else {
1460                                         entity->parameter.read = true;
1461                                 }
1462                         }
1463                         return;
1464                 }
1465
1466                 case EXPR_CALL:
1467                         // TODO respect pure/const
1468                         mark_vars_read(expr->call.function, NULL);
1469                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1470                                 mark_vars_read(arg->expression, NULL);
1471                         }
1472                         return;
1473
1474                 case EXPR_CONDITIONAL:
1475                         // TODO lhs_decl should depend on whether true/false have an effect
1476                         mark_vars_read(expr->conditional.condition, NULL);
1477                         if (expr->conditional.true_expression != NULL)
1478                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1479                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1480                         return;
1481
1482                 case EXPR_SELECT:
1483                         if (lhs_ent == ENT_ANY
1484                                         && !is_type_compound(skip_typeref(expr->base.type)))
1485                                 lhs_ent = NULL;
1486                         mark_vars_read(expr->select.compound, lhs_ent);
1487                         return;
1488
1489                 case EXPR_ARRAY_ACCESS: {
1490                         expression_t *const ref = expr->array_access.array_ref;
1491                         mark_vars_read(ref, lhs_ent);
1492                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1493                         mark_vars_read(expr->array_access.index, lhs_ent);
1494                         return;
1495                 }
1496
1497                 case EXPR_VA_ARG:
1498                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1499                         return;
1500
1501                 case EXPR_VA_COPY:
1502                         mark_vars_read(expr->va_copye.src, lhs_ent);
1503                         return;
1504
1505                 case EXPR_UNARY_CAST:
1506                         /* Special case: Use void cast to mark a variable as "read" */
1507                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1508                                 lhs_ent = NULL;
1509                         goto unary;
1510
1511
1512                 case EXPR_UNARY_THROW:
1513                         if (expr->unary.value == NULL)
1514                                 return;
1515                         /* FALLTHROUGH */
1516                 case EXPR_UNARY_DEREFERENCE:
1517                 case EXPR_UNARY_DELETE:
1518                 case EXPR_UNARY_DELETE_ARRAY:
1519                         if (lhs_ent == ENT_ANY)
1520                                 lhs_ent = NULL;
1521                         goto unary;
1522
1523                 case EXPR_UNARY_NEGATE:
1524                 case EXPR_UNARY_PLUS:
1525                 case EXPR_UNARY_BITWISE_NEGATE:
1526                 case EXPR_UNARY_NOT:
1527                 case EXPR_UNARY_TAKE_ADDRESS:
1528                 case EXPR_UNARY_POSTFIX_INCREMENT:
1529                 case EXPR_UNARY_POSTFIX_DECREMENT:
1530                 case EXPR_UNARY_PREFIX_INCREMENT:
1531                 case EXPR_UNARY_PREFIX_DECREMENT:
1532                 case EXPR_UNARY_CAST_IMPLICIT:
1533                 case EXPR_UNARY_ASSUME:
1534 unary:
1535                         mark_vars_read(expr->unary.value, lhs_ent);
1536                         return;
1537
1538                 case EXPR_BINARY_ADD:
1539                 case EXPR_BINARY_SUB:
1540                 case EXPR_BINARY_MUL:
1541                 case EXPR_BINARY_DIV:
1542                 case EXPR_BINARY_MOD:
1543                 case EXPR_BINARY_EQUAL:
1544                 case EXPR_BINARY_NOTEQUAL:
1545                 case EXPR_BINARY_LESS:
1546                 case EXPR_BINARY_LESSEQUAL:
1547                 case EXPR_BINARY_GREATER:
1548                 case EXPR_BINARY_GREATEREQUAL:
1549                 case EXPR_BINARY_BITWISE_AND:
1550                 case EXPR_BINARY_BITWISE_OR:
1551                 case EXPR_BINARY_BITWISE_XOR:
1552                 case EXPR_BINARY_LOGICAL_AND:
1553                 case EXPR_BINARY_LOGICAL_OR:
1554                 case EXPR_BINARY_SHIFTLEFT:
1555                 case EXPR_BINARY_SHIFTRIGHT:
1556                 case EXPR_BINARY_COMMA:
1557                 case EXPR_BINARY_ISGREATER:
1558                 case EXPR_BINARY_ISGREATEREQUAL:
1559                 case EXPR_BINARY_ISLESS:
1560                 case EXPR_BINARY_ISLESSEQUAL:
1561                 case EXPR_BINARY_ISLESSGREATER:
1562                 case EXPR_BINARY_ISUNORDERED:
1563                         mark_vars_read(expr->binary.left,  lhs_ent);
1564                         mark_vars_read(expr->binary.right, lhs_ent);
1565                         return;
1566
1567                 case EXPR_BINARY_ASSIGN:
1568                 case EXPR_BINARY_MUL_ASSIGN:
1569                 case EXPR_BINARY_DIV_ASSIGN:
1570                 case EXPR_BINARY_MOD_ASSIGN:
1571                 case EXPR_BINARY_ADD_ASSIGN:
1572                 case EXPR_BINARY_SUB_ASSIGN:
1573                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1574                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1575                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1576                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1577                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1578                         if (lhs_ent == ENT_ANY)
1579                                 lhs_ent = NULL;
1580                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1581                         mark_vars_read(expr->binary.right, lhs_ent);
1582                         return;
1583                 }
1584
1585                 case EXPR_VA_START:
1586                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1587                         return;
1588
1589                 EXPR_LITERAL_CASES
1590                 case EXPR_UNKNOWN:
1591                 case EXPR_INVALID:
1592                 case EXPR_STRING_LITERAL:
1593                 case EXPR_WIDE_STRING_LITERAL:
1594                 case EXPR_COMPOUND_LITERAL: // TODO init?
1595                 case EXPR_SIZEOF:
1596                 case EXPR_CLASSIFY_TYPE:
1597                 case EXPR_ALIGNOF:
1598                 case EXPR_FUNCNAME:
1599                 case EXPR_BUILTIN_CONSTANT_P:
1600                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1601                 case EXPR_OFFSETOF:
1602                 case EXPR_STATEMENT: // TODO
1603                 case EXPR_LABEL_ADDRESS:
1604                 case EXPR_REFERENCE_ENUM_VALUE:
1605                         return;
1606         }
1607
1608         panic("unhandled expression");
1609 }
1610
1611 static designator_t *parse_designation(void)
1612 {
1613         designator_t  *result = NULL;
1614         designator_t **anchor = &result;
1615
1616         for (;;) {
1617                 designator_t *designator;
1618                 switch (token.type) {
1619                 case '[':
1620                         designator = allocate_ast_zero(sizeof(designator[0]));
1621                         designator->source_position = token.source_position;
1622                         next_token();
1623                         add_anchor_token(']');
1624                         designator->array_index = parse_constant_expression();
1625                         rem_anchor_token(']');
1626                         expect(']', end_error);
1627                         break;
1628                 case '.':
1629                         designator = allocate_ast_zero(sizeof(designator[0]));
1630                         designator->source_position = token.source_position;
1631                         next_token();
1632                         if (token.type != T_IDENTIFIER) {
1633                                 parse_error_expected("while parsing designator",
1634                                                      T_IDENTIFIER, NULL);
1635                                 return NULL;
1636                         }
1637                         designator->symbol = token.symbol;
1638                         next_token();
1639                         break;
1640                 default:
1641                         expect('=', end_error);
1642                         return result;
1643                 }
1644
1645                 assert(designator != NULL);
1646                 *anchor = designator;
1647                 anchor  = &designator->next;
1648         }
1649 end_error:
1650         return NULL;
1651 }
1652
1653 static initializer_t *initializer_from_string(array_type_t *const type,
1654                                               const string_t *const string)
1655 {
1656         /* TODO: check len vs. size of array type */
1657         (void) type;
1658
1659         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1660         initializer->string.string = *string;
1661
1662         return initializer;
1663 }
1664
1665 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1666                                                    const string_t *const string)
1667 {
1668         /* TODO: check len vs. size of array type */
1669         (void) type;
1670
1671         initializer_t *const initializer =
1672                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1673         initializer->wide_string.string = *string;
1674
1675         return initializer;
1676 }
1677
1678 /**
1679  * Build an initializer from a given expression.
1680  */
1681 static initializer_t *initializer_from_expression(type_t *orig_type,
1682                                                   expression_t *expression)
1683 {
1684         /* TODO check that expression is a constant expression */
1685
1686         /* §6.7.8.14/15 char array may be initialized by string literals */
1687         type_t *type           = skip_typeref(orig_type);
1688         type_t *expr_type_orig = expression->base.type;
1689         type_t *expr_type      = skip_typeref(expr_type_orig);
1690
1691         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1692                 array_type_t *const array_type   = &type->array;
1693                 type_t       *const element_type = skip_typeref(array_type->element_type);
1694
1695                 if (element_type->kind == TYPE_ATOMIC) {
1696                         atomic_type_kind_t akind = element_type->atomic.akind;
1697                         switch (expression->kind) {
1698                         case EXPR_STRING_LITERAL:
1699                                 if (akind == ATOMIC_TYPE_CHAR
1700                                                 || akind == ATOMIC_TYPE_SCHAR
1701                                                 || akind == ATOMIC_TYPE_UCHAR) {
1702                                         return initializer_from_string(array_type,
1703                                                         &expression->string_literal.value);
1704                                 }
1705                                 break;
1706
1707                         case EXPR_WIDE_STRING_LITERAL: {
1708                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1709                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1710                                         return initializer_from_wide_string(array_type,
1711                                                         &expression->string_literal.value);
1712                                 }
1713                                 break;
1714                         }
1715
1716                         default:
1717                                 break;
1718                         }
1719                 }
1720         }
1721
1722         assign_error_t error = semantic_assign(type, expression);
1723         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1724                 return NULL;
1725         report_assign_error(error, type, expression, "initializer",
1726                             &expression->base.source_position);
1727
1728         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1729         result->value.value = create_implicit_cast(expression, type);
1730
1731         return result;
1732 }
1733
1734 /**
1735  * Checks if a given expression can be used as a constant initializer.
1736  */
1737 static bool is_initializer_constant(const expression_t *expression)
1738 {
1739         return is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
1740                is_linker_constant(expression)     != EXPR_CLASS_VARIABLE;
1741 }
1742
1743 /**
1744  * Parses an scalar initializer.
1745  *
1746  * §6.7.8.11; eat {} without warning
1747  */
1748 static initializer_t *parse_scalar_initializer(type_t *type,
1749                                                bool must_be_constant)
1750 {
1751         /* there might be extra {} hierarchies */
1752         int braces = 0;
1753         if (token.type == '{') {
1754                 if (warning.other)
1755                         warningf(HERE, "extra curly braces around scalar initializer");
1756                 do {
1757                         eat('{');
1758                         ++braces;
1759                 } while (token.type == '{');
1760         }
1761
1762         expression_t *expression = parse_assignment_expression();
1763         mark_vars_read(expression, NULL);
1764         if (must_be_constant && !is_initializer_constant(expression)) {
1765                 errorf(&expression->base.source_position,
1766                        "initialisation expression '%E' is not constant",
1767                        expression);
1768         }
1769
1770         initializer_t *initializer = initializer_from_expression(type, expression);
1771
1772         if (initializer == NULL) {
1773                 errorf(&expression->base.source_position,
1774                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1775                        expression, expression->base.type, type);
1776                 /* TODO */
1777                 return NULL;
1778         }
1779
1780         bool additional_warning_displayed = false;
1781         while (braces > 0) {
1782                 next_if(',');
1783                 if (token.type != '}') {
1784                         if (!additional_warning_displayed && warning.other) {
1785                                 warningf(HERE, "additional elements in scalar initializer");
1786                                 additional_warning_displayed = true;
1787                         }
1788                 }
1789                 eat_block();
1790                 braces--;
1791         }
1792
1793         return initializer;
1794 }
1795
1796 /**
1797  * An entry in the type path.
1798  */
1799 typedef struct type_path_entry_t type_path_entry_t;
1800 struct type_path_entry_t {
1801         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1802         union {
1803                 size_t         index;          /**< For array types: the current index. */
1804                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1805         } v;
1806 };
1807
1808 /**
1809  * A type path expression a position inside compound or array types.
1810  */
1811 typedef struct type_path_t type_path_t;
1812 struct type_path_t {
1813         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1814         type_t            *top_type;     /**< type of the element the path points */
1815         size_t             max_index;    /**< largest index in outermost array */
1816 };
1817
1818 /**
1819  * Prints a type path for debugging.
1820  */
1821 static __attribute__((unused)) void debug_print_type_path(
1822                 const type_path_t *path)
1823 {
1824         size_t len = ARR_LEN(path->path);
1825
1826         for (size_t i = 0; i < len; ++i) {
1827                 const type_path_entry_t *entry = & path->path[i];
1828
1829                 type_t *type = skip_typeref(entry->type);
1830                 if (is_type_compound(type)) {
1831                         /* in gcc mode structs can have no members */
1832                         if (entry->v.compound_entry == NULL) {
1833                                 assert(i == len-1);
1834                                 continue;
1835                         }
1836                         fprintf(stderr, ".%s",
1837                                 entry->v.compound_entry->base.symbol->string);
1838                 } else if (is_type_array(type)) {
1839                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1840                 } else {
1841                         fprintf(stderr, "-INVALID-");
1842                 }
1843         }
1844         if (path->top_type != NULL) {
1845                 fprintf(stderr, "  (");
1846                 print_type(path->top_type);
1847                 fprintf(stderr, ")");
1848         }
1849 }
1850
1851 /**
1852  * Return the top type path entry, ie. in a path
1853  * (type).a.b returns the b.
1854  */
1855 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1856 {
1857         size_t len = ARR_LEN(path->path);
1858         assert(len > 0);
1859         return &path->path[len-1];
1860 }
1861
1862 /**
1863  * Enlarge the type path by an (empty) element.
1864  */
1865 static type_path_entry_t *append_to_type_path(type_path_t *path)
1866 {
1867         size_t len = ARR_LEN(path->path);
1868         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1869
1870         type_path_entry_t *result = & path->path[len];
1871         memset(result, 0, sizeof(result[0]));
1872         return result;
1873 }
1874
1875 /**
1876  * Descending into a sub-type. Enter the scope of the current top_type.
1877  */
1878 static void descend_into_subtype(type_path_t *path)
1879 {
1880         type_t *orig_top_type = path->top_type;
1881         type_t *top_type      = skip_typeref(orig_top_type);
1882
1883         type_path_entry_t *top = append_to_type_path(path);
1884         top->type              = top_type;
1885
1886         if (is_type_compound(top_type)) {
1887                 compound_t *compound  = top_type->compound.compound;
1888                 entity_t   *entry     = compound->members.entities;
1889
1890                 if (entry != NULL) {
1891                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
1892                         top->v.compound_entry = &entry->declaration;
1893                         path->top_type = entry->declaration.type;
1894                 } else {
1895                         path->top_type = NULL;
1896                 }
1897         } else if (is_type_array(top_type)) {
1898                 top->v.index   = 0;
1899                 path->top_type = top_type->array.element_type;
1900         } else {
1901                 assert(!is_type_valid(top_type));
1902         }
1903 }
1904
1905 /**
1906  * Pop an entry from the given type path, ie. returning from
1907  * (type).a.b to (type).a
1908  */
1909 static void ascend_from_subtype(type_path_t *path)
1910 {
1911         type_path_entry_t *top = get_type_path_top(path);
1912
1913         path->top_type = top->type;
1914
1915         size_t len = ARR_LEN(path->path);
1916         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1917 }
1918
1919 /**
1920  * Pop entries from the given type path until the given
1921  * path level is reached.
1922  */
1923 static void ascend_to(type_path_t *path, size_t top_path_level)
1924 {
1925         size_t len = ARR_LEN(path->path);
1926
1927         while (len > top_path_level) {
1928                 ascend_from_subtype(path);
1929                 len = ARR_LEN(path->path);
1930         }
1931 }
1932
1933 static bool walk_designator(type_path_t *path, const designator_t *designator,
1934                             bool used_in_offsetof)
1935 {
1936         for (; designator != NULL; designator = designator->next) {
1937                 type_path_entry_t *top       = get_type_path_top(path);
1938                 type_t            *orig_type = top->type;
1939
1940                 type_t *type = skip_typeref(orig_type);
1941
1942                 if (designator->symbol != NULL) {
1943                         symbol_t *symbol = designator->symbol;
1944                         if (!is_type_compound(type)) {
1945                                 if (is_type_valid(type)) {
1946                                         errorf(&designator->source_position,
1947                                                "'.%Y' designator used for non-compound type '%T'",
1948                                                symbol, orig_type);
1949                                 }
1950
1951                                 top->type             = type_error_type;
1952                                 top->v.compound_entry = NULL;
1953                                 orig_type             = type_error_type;
1954                         } else {
1955                                 compound_t *compound = type->compound.compound;
1956                                 entity_t   *iter     = compound->members.entities;
1957                                 for (; iter != NULL; iter = iter->base.next) {
1958                                         if (iter->base.symbol == symbol) {
1959                                                 break;
1960                                         }
1961                                 }
1962                                 if (iter == NULL) {
1963                                         errorf(&designator->source_position,
1964                                                "'%T' has no member named '%Y'", orig_type, symbol);
1965                                         return false;
1966                                 }
1967                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1968                                 if (used_in_offsetof) {
1969                                         type_t *real_type = skip_typeref(iter->declaration.type);
1970                                         if (real_type->kind == TYPE_BITFIELD) {
1971                                                 errorf(&designator->source_position,
1972                                                        "offsetof designator '%Y' must not specify bitfield",
1973                                                        symbol);
1974                                                 return false;
1975                                         }
1976                                 }
1977
1978                                 top->type             = orig_type;
1979                                 top->v.compound_entry = &iter->declaration;
1980                                 orig_type             = iter->declaration.type;
1981                         }
1982                 } else {
1983                         expression_t *array_index = designator->array_index;
1984                         assert(designator->array_index != NULL);
1985
1986                         if (!is_type_array(type)) {
1987                                 if (is_type_valid(type)) {
1988                                         errorf(&designator->source_position,
1989                                                "[%E] designator used for non-array type '%T'",
1990                                                array_index, orig_type);
1991                                 }
1992                                 return false;
1993                         }
1994
1995                         long index = fold_constant_to_int(array_index);
1996                         if (!used_in_offsetof) {
1997                                 if (index < 0) {
1998                                         errorf(&designator->source_position,
1999                                                "array index [%E] must be positive", array_index);
2000                                 } else if (type->array.size_constant) {
2001                                         long array_size = type->array.size;
2002                                         if (index >= array_size) {
2003                                                 errorf(&designator->source_position,
2004                                                        "designator [%E] (%d) exceeds array size %d",
2005                                                        array_index, index, array_size);
2006                                         }
2007                                 }
2008                         }
2009
2010                         top->type    = orig_type;
2011                         top->v.index = (size_t) index;
2012                         orig_type    = type->array.element_type;
2013                 }
2014                 path->top_type = orig_type;
2015
2016                 if (designator->next != NULL) {
2017                         descend_into_subtype(path);
2018                 }
2019         }
2020         return true;
2021 }
2022
2023 static void advance_current_object(type_path_t *path, size_t top_path_level)
2024 {
2025         type_path_entry_t *top = get_type_path_top(path);
2026
2027         type_t *type = skip_typeref(top->type);
2028         if (is_type_union(type)) {
2029                 /* in unions only the first element is initialized */
2030                 top->v.compound_entry = NULL;
2031         } else if (is_type_struct(type)) {
2032                 declaration_t *entry = top->v.compound_entry;
2033
2034                 entity_t *next_entity = entry->base.next;
2035                 if (next_entity != NULL) {
2036                         assert(is_declaration(next_entity));
2037                         entry = &next_entity->declaration;
2038                 } else {
2039                         entry = NULL;
2040                 }
2041
2042                 top->v.compound_entry = entry;
2043                 if (entry != NULL) {
2044                         path->top_type = entry->type;
2045                         return;
2046                 }
2047         } else if (is_type_array(type)) {
2048                 assert(is_type_array(type));
2049
2050                 top->v.index++;
2051
2052                 if (!type->array.size_constant || top->v.index < type->array.size) {
2053                         return;
2054                 }
2055         } else {
2056                 assert(!is_type_valid(type));
2057                 return;
2058         }
2059
2060         /* we're past the last member of the current sub-aggregate, try if we
2061          * can ascend in the type hierarchy and continue with another subobject */
2062         size_t len = ARR_LEN(path->path);
2063
2064         if (len > top_path_level) {
2065                 ascend_from_subtype(path);
2066                 advance_current_object(path, top_path_level);
2067         } else {
2068                 path->top_type = NULL;
2069         }
2070 }
2071
2072 /**
2073  * skip any {...} blocks until a closing bracket is reached.
2074  */
2075 static void skip_initializers(void)
2076 {
2077         next_if('{');
2078
2079         while (token.type != '}') {
2080                 if (token.type == T_EOF)
2081                         return;
2082                 if (token.type == '{') {
2083                         eat_block();
2084                         continue;
2085                 }
2086                 next_token();
2087         }
2088 }
2089
2090 static initializer_t *create_empty_initializer(void)
2091 {
2092         static initializer_t empty_initializer
2093                 = { .list = { { INITIALIZER_LIST }, 0 } };
2094         return &empty_initializer;
2095 }
2096
2097 /**
2098  * Parse a part of an initialiser for a struct or union,
2099  */
2100 static initializer_t *parse_sub_initializer(type_path_t *path,
2101                 type_t *outer_type, size_t top_path_level,
2102                 parse_initializer_env_t *env)
2103 {
2104         if (token.type == '}') {
2105                 /* empty initializer */
2106                 return create_empty_initializer();
2107         }
2108
2109         type_t *orig_type = path->top_type;
2110         type_t *type      = NULL;
2111
2112         if (orig_type == NULL) {
2113                 /* We are initializing an empty compound. */
2114         } else {
2115                 type = skip_typeref(orig_type);
2116         }
2117
2118         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2119
2120         while (true) {
2121                 designator_t *designator = NULL;
2122                 if (token.type == '.' || token.type == '[') {
2123                         designator = parse_designation();
2124                         goto finish_designator;
2125                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2126                         /* GNU-style designator ("identifier: value") */
2127                         designator = allocate_ast_zero(sizeof(designator[0]));
2128                         designator->source_position = token.source_position;
2129                         designator->symbol          = token.symbol;
2130                         eat(T_IDENTIFIER);
2131                         eat(':');
2132
2133 finish_designator:
2134                         /* reset path to toplevel, evaluate designator from there */
2135                         ascend_to(path, top_path_level);
2136                         if (!walk_designator(path, designator, false)) {
2137                                 /* can't continue after designation error */
2138                                 goto end_error;
2139                         }
2140
2141                         initializer_t *designator_initializer
2142                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2143                         designator_initializer->designator.designator = designator;
2144                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2145
2146                         orig_type = path->top_type;
2147                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2148                 }
2149
2150                 initializer_t *sub;
2151
2152                 if (token.type == '{') {
2153                         if (type != NULL && is_type_scalar(type)) {
2154                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2155                         } else {
2156                                 if (type == NULL) {
2157                                         if (env->entity != NULL) {
2158                                                 errorf(HERE,
2159                                                      "extra brace group at end of initializer for '%Y'",
2160                                                      env->entity->base.symbol);
2161                                         } else {
2162                                                 errorf(HERE, "extra brace group at end of initializer");
2163                                         }
2164                                         eat('{');
2165                                 } else {
2166                                         eat('{');
2167                                         descend_into_subtype(path);
2168                                 }
2169
2170                                 add_anchor_token('}');
2171                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2172                                                             env);
2173                                 rem_anchor_token('}');
2174
2175                                 if (type != NULL) {
2176                                         ascend_from_subtype(path);
2177                                         expect('}', end_error);
2178                                 } else {
2179                                         expect('}', end_error);
2180                                         goto error_parse_next;
2181                                 }
2182                         }
2183                 } else {
2184                         /* must be an expression */
2185                         expression_t *expression = parse_assignment_expression();
2186                         mark_vars_read(expression, NULL);
2187
2188                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2189                                 errorf(&expression->base.source_position,
2190                                        "Initialisation expression '%E' is not constant",
2191                                        expression);
2192                         }
2193
2194                         if (type == NULL) {
2195                                 /* we are already outside, ... */
2196                                 if (outer_type == NULL)
2197                                         goto error_parse_next;
2198                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2199                                 if (is_type_compound(outer_type_skip) &&
2200                                                 !outer_type_skip->compound.compound->complete) {
2201                                         goto error_parse_next;
2202                                 }
2203
2204                                 if (warning.other) {
2205                                         source_position_t const* const pos = &expression->base.source_position;
2206                                         if (env->entity != NULL) {
2207                                                 warningf(pos, "excess elements in initializer for '%Y'", env->entity->base.symbol);
2208                                         } else {
2209                                                 warningf(pos, "excess elements in initializer");
2210                                         }
2211                                 }
2212                                 goto error_parse_next;
2213                         }
2214
2215                         /* handle { "string" } special case */
2216                         if ((expression->kind == EXPR_STRING_LITERAL
2217                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2218                                         && outer_type != NULL) {
2219                                 sub = initializer_from_expression(outer_type, expression);
2220                                 if (sub != NULL) {
2221                                         next_if(',');
2222                                         if (token.type != '}' && warning.other) {
2223                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2224                                                                  orig_type);
2225                                         }
2226                                         /* TODO: eat , ... */
2227                                         return sub;
2228                                 }
2229                         }
2230
2231                         /* descend into subtypes until expression matches type */
2232                         while (true) {
2233                                 orig_type = path->top_type;
2234                                 type      = skip_typeref(orig_type);
2235
2236                                 sub = initializer_from_expression(orig_type, expression);
2237                                 if (sub != NULL) {
2238                                         break;
2239                                 }
2240                                 if (!is_type_valid(type)) {
2241                                         goto end_error;
2242                                 }
2243                                 if (is_type_scalar(type)) {
2244                                         errorf(&expression->base.source_position,
2245                                                         "expression '%E' doesn't match expected type '%T'",
2246                                                         expression, orig_type);
2247                                         goto end_error;
2248                                 }
2249
2250                                 descend_into_subtype(path);
2251                         }
2252                 }
2253
2254                 /* update largest index of top array */
2255                 const type_path_entry_t *first      = &path->path[0];
2256                 type_t                  *first_type = first->type;
2257                 first_type                          = skip_typeref(first_type);
2258                 if (is_type_array(first_type)) {
2259                         size_t index = first->v.index;
2260                         if (index > path->max_index)
2261                                 path->max_index = index;
2262                 }
2263
2264                 /* append to initializers list */
2265                 ARR_APP1(initializer_t*, initializers, sub);
2266
2267 error_parse_next:
2268                 if (token.type == '}') {
2269                         break;
2270                 }
2271                 expect(',', end_error);
2272                 if (token.type == '}') {
2273                         break;
2274                 }
2275
2276                 if (type != NULL) {
2277                         /* advance to the next declaration if we are not at the end */
2278                         advance_current_object(path, top_path_level);
2279                         orig_type = path->top_type;
2280                         if (orig_type != NULL)
2281                                 type = skip_typeref(orig_type);
2282                         else
2283                                 type = NULL;
2284                 }
2285         }
2286
2287         size_t len  = ARR_LEN(initializers);
2288         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2289         initializer_t *result = allocate_ast_zero(size);
2290         result->kind          = INITIALIZER_LIST;
2291         result->list.len      = len;
2292         memcpy(&result->list.initializers, initializers,
2293                len * sizeof(initializers[0]));
2294
2295         DEL_ARR_F(initializers);
2296         ascend_to(path, top_path_level+1);
2297
2298         return result;
2299
2300 end_error:
2301         skip_initializers();
2302         DEL_ARR_F(initializers);
2303         ascend_to(path, top_path_level+1);
2304         return NULL;
2305 }
2306
2307 static expression_t *make_size_literal(size_t value)
2308 {
2309         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2310         literal->base.type    = type_size_t;
2311
2312         char buf[128];
2313         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2314         literal->literal.value = make_string(buf);
2315
2316         return literal;
2317 }
2318
2319 /**
2320  * Parses an initializer. Parsers either a compound literal
2321  * (env->declaration == NULL) or an initializer of a declaration.
2322  */
2323 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2324 {
2325         type_t        *type      = skip_typeref(env->type);
2326         size_t         max_index = 0;
2327         initializer_t *result;
2328
2329         if (is_type_scalar(type)) {
2330                 result = parse_scalar_initializer(type, env->must_be_constant);
2331         } else if (token.type == '{') {
2332                 eat('{');
2333
2334                 type_path_t path;
2335                 memset(&path, 0, sizeof(path));
2336                 path.top_type = env->type;
2337                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2338
2339                 descend_into_subtype(&path);
2340
2341                 add_anchor_token('}');
2342                 result = parse_sub_initializer(&path, env->type, 1, env);
2343                 rem_anchor_token('}');
2344
2345                 max_index = path.max_index;
2346                 DEL_ARR_F(path.path);
2347
2348                 expect('}', end_error);
2349 end_error:;
2350         } else {
2351                 /* parse_scalar_initializer() also works in this case: we simply
2352                  * have an expression without {} around it */
2353                 result = parse_scalar_initializer(type, env->must_be_constant);
2354         }
2355
2356         /* §6.7.8:22 array initializers for arrays with unknown size determine
2357          * the array type size */
2358         if (is_type_array(type) && type->array.size_expression == NULL
2359                         && result != NULL) {
2360                 size_t size;
2361                 switch (result->kind) {
2362                 case INITIALIZER_LIST:
2363                         assert(max_index != 0xdeadbeaf);
2364                         size = max_index + 1;
2365                         break;
2366
2367                 case INITIALIZER_STRING:
2368                         size = result->string.string.size;
2369                         break;
2370
2371                 case INITIALIZER_WIDE_STRING:
2372                         size = result->wide_string.string.size;
2373                         break;
2374
2375                 case INITIALIZER_DESIGNATOR:
2376                 case INITIALIZER_VALUE:
2377                         /* can happen for parse errors */
2378                         size = 0;
2379                         break;
2380
2381                 default:
2382                         internal_errorf(HERE, "invalid initializer type");
2383                 }
2384
2385                 type_t *new_type = duplicate_type(type);
2386
2387                 new_type->array.size_expression   = make_size_literal(size);
2388                 new_type->array.size_constant     = true;
2389                 new_type->array.has_implicit_size = true;
2390                 new_type->array.size              = size;
2391                 env->type = new_type;
2392         }
2393
2394         return result;
2395 }
2396
2397 static void append_entity(scope_t *scope, entity_t *entity)
2398 {
2399         if (scope->last_entity != NULL) {
2400                 scope->last_entity->base.next = entity;
2401         } else {
2402                 scope->entities = entity;
2403         }
2404         entity->base.parent_entity = current_entity;
2405         scope->last_entity         = entity;
2406 }
2407
2408
2409 static compound_t *parse_compound_type_specifier(bool is_struct)
2410 {
2411         source_position_t const pos = *HERE;
2412         eat(is_struct ? T_struct : T_union);
2413
2414         symbol_t    *symbol     = NULL;
2415         entity_t    *entity     = NULL;
2416         attribute_t *attributes = NULL;
2417
2418         if (token.type == T___attribute__) {
2419                 attributes = parse_attributes(NULL);
2420         }
2421
2422         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2423         if (token.type == T_IDENTIFIER) {
2424                 /* the compound has a name, check if we have seen it already */
2425                 symbol = token.symbol;
2426                 entity = get_tag(symbol, kind);
2427                 next_token();
2428
2429                 if (entity != NULL) {
2430                         if (entity->base.parent_scope != current_scope &&
2431                             (token.type == '{' || token.type == ';')) {
2432                                 /* we're in an inner scope and have a definition. Shadow
2433                                  * existing definition in outer scope */
2434                                 entity = NULL;
2435                         } else if (entity->compound.complete && token.type == '{') {
2436                                 source_position_t const *const ppos = &entity->base.source_position;
2437                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2438                                 /* clear members in the hope to avoid further errors */
2439                                 entity->compound.members.entities = NULL;
2440                         }
2441                 }
2442         } else if (token.type != '{') {
2443                 char const *const msg =
2444                         is_struct ? "while parsing struct type specifier" :
2445                                     "while parsing union type specifier";
2446                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2447
2448                 return NULL;
2449         }
2450
2451         if (entity == NULL) {
2452                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol);
2453                 entity->compound.alignment   = 1;
2454                 entity->base.source_position = pos;
2455                 entity->base.parent_scope    = current_scope;
2456                 if (symbol != NULL) {
2457                         environment_push(entity);
2458                 }
2459                 append_entity(current_scope, entity);
2460         }
2461
2462         if (token.type == '{') {
2463                 parse_compound_type_entries(&entity->compound);
2464
2465                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2466                 if (symbol == NULL) {
2467                         assert(anonymous_entity == NULL);
2468                         anonymous_entity = entity;
2469                 }
2470         }
2471
2472         if (attributes != NULL) {
2473                 handle_entity_attributes(attributes, entity);
2474         }
2475
2476         return &entity->compound;
2477 }
2478
2479 static void parse_enum_entries(type_t *const enum_type)
2480 {
2481         eat('{');
2482
2483         if (token.type == '}') {
2484                 errorf(HERE, "empty enum not allowed");
2485                 next_token();
2486                 return;
2487         }
2488
2489         add_anchor_token('}');
2490         do {
2491                 if (token.type != T_IDENTIFIER) {
2492                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2493                         eat_block();
2494                         rem_anchor_token('}');
2495                         return;
2496                 }
2497
2498                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, token.symbol);
2499                 entity->enum_value.enum_type = enum_type;
2500                 entity->base.source_position = token.source_position;
2501                 next_token();
2502
2503                 if (next_if('=')) {
2504                         expression_t *value = parse_constant_expression();
2505
2506                         value = create_implicit_cast(value, enum_type);
2507                         entity->enum_value.value = value;
2508
2509                         /* TODO semantic */
2510                 }
2511
2512                 record_entity(entity, false);
2513         } while (next_if(',') && token.type != '}');
2514         rem_anchor_token('}');
2515
2516         expect('}', end_error);
2517
2518 end_error:
2519         ;
2520 }
2521
2522 static type_t *parse_enum_specifier(void)
2523 {
2524         source_position_t const pos = *HERE;
2525         entity_t               *entity;
2526         symbol_t               *symbol;
2527
2528         eat(T_enum);
2529         switch (token.type) {
2530                 case T_IDENTIFIER:
2531                         symbol = token.symbol;
2532                         entity = get_tag(symbol, ENTITY_ENUM);
2533                         next_token();
2534
2535                         if (entity != NULL) {
2536                                 if (entity->base.parent_scope != current_scope &&
2537                                                 (token.type == '{' || token.type == ';')) {
2538                                         /* we're in an inner scope and have a definition. Shadow
2539                                          * existing definition in outer scope */
2540                                         entity = NULL;
2541                                 } else if (entity->enume.complete && token.type == '{') {
2542                                         source_position_t const *const ppos = &entity->base.source_position;
2543                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2544                                 }
2545                         }
2546                         break;
2547
2548                 case '{':
2549                         entity = NULL;
2550                         symbol = NULL;
2551                         break;
2552
2553                 default:
2554                         parse_error_expected("while parsing enum type specifier",
2555                                         T_IDENTIFIER, '{', NULL);
2556                         return NULL;
2557         }
2558
2559         if (entity == NULL) {
2560                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol);
2561                 entity->base.source_position = pos;
2562                 entity->base.parent_scope    = current_scope;
2563         }
2564
2565         type_t *const type = allocate_type_zero(TYPE_ENUM);
2566         type->enumt.enume  = &entity->enume;
2567         type->enumt.akind  = ATOMIC_TYPE_INT;
2568
2569         if (token.type == '{') {
2570                 if (symbol != NULL) {
2571                         environment_push(entity);
2572                 }
2573                 append_entity(current_scope, entity);
2574                 entity->enume.complete = true;
2575
2576                 parse_enum_entries(type);
2577                 parse_attributes(NULL);
2578
2579                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2580                 if (symbol == NULL) {
2581                         assert(anonymous_entity == NULL);
2582                         anonymous_entity = entity;
2583                 }
2584         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2585                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2586         }
2587
2588         return type;
2589 }
2590
2591 /**
2592  * if a symbol is a typedef to another type, return true
2593  */
2594 static bool is_typedef_symbol(symbol_t *symbol)
2595 {
2596         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2597         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2598 }
2599
2600 static type_t *parse_typeof(void)
2601 {
2602         eat(T___typeof__);
2603
2604         type_t *type;
2605
2606         expect('(', end_error);
2607         add_anchor_token(')');
2608
2609         expression_t *expression  = NULL;
2610
2611         bool old_type_prop     = in_type_prop;
2612         bool old_gcc_extension = in_gcc_extension;
2613         in_type_prop           = true;
2614
2615         while (next_if(T___extension__)) {
2616                 /* This can be a prefix to a typename or an expression. */
2617                 in_gcc_extension = true;
2618         }
2619         switch (token.type) {
2620         case T_IDENTIFIER:
2621                 if (is_typedef_symbol(token.symbol)) {
2622         DECLARATION_START
2623                         type = parse_typename();
2624                 } else {
2625         default:
2626                         expression = parse_expression();
2627                         type       = revert_automatic_type_conversion(expression);
2628                 }
2629                 break;
2630         }
2631         in_type_prop     = old_type_prop;
2632         in_gcc_extension = old_gcc_extension;
2633
2634         rem_anchor_token(')');
2635         expect(')', end_error);
2636
2637         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2638         typeof_type->typeoft.expression  = expression;
2639         typeof_type->typeoft.typeof_type = type;
2640
2641         return typeof_type;
2642 end_error:
2643         return NULL;
2644 }
2645
2646 typedef enum specifiers_t {
2647         SPECIFIER_SIGNED    = 1 << 0,
2648         SPECIFIER_UNSIGNED  = 1 << 1,
2649         SPECIFIER_LONG      = 1 << 2,
2650         SPECIFIER_INT       = 1 << 3,
2651         SPECIFIER_DOUBLE    = 1 << 4,
2652         SPECIFIER_CHAR      = 1 << 5,
2653         SPECIFIER_WCHAR_T   = 1 << 6,
2654         SPECIFIER_SHORT     = 1 << 7,
2655         SPECIFIER_LONG_LONG = 1 << 8,
2656         SPECIFIER_FLOAT     = 1 << 9,
2657         SPECIFIER_BOOL      = 1 << 10,
2658         SPECIFIER_VOID      = 1 << 11,
2659         SPECIFIER_INT8      = 1 << 12,
2660         SPECIFIER_INT16     = 1 << 13,
2661         SPECIFIER_INT32     = 1 << 14,
2662         SPECIFIER_INT64     = 1 << 15,
2663         SPECIFIER_INT128    = 1 << 16,
2664         SPECIFIER_COMPLEX   = 1 << 17,
2665         SPECIFIER_IMAGINARY = 1 << 18,
2666 } specifiers_t;
2667
2668 static type_t *get_typedef_type(symbol_t *symbol)
2669 {
2670         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2671         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2672                 return NULL;
2673
2674         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2675         type->typedeft.typedefe = &entity->typedefe;
2676
2677         return type;
2678 }
2679
2680 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2681 {
2682         expect('(', end_error);
2683
2684         attribute_property_argument_t *property
2685                 = allocate_ast_zero(sizeof(*property));
2686
2687         do {
2688                 if (token.type != T_IDENTIFIER) {
2689                         parse_error_expected("while parsing property declspec",
2690                                              T_IDENTIFIER, NULL);
2691                         goto end_error;
2692                 }
2693
2694                 symbol_t **prop;
2695                 symbol_t  *symbol = token.symbol;
2696                 if (strcmp(symbol->string, "put") == 0) {
2697                         prop = &property->put_symbol;
2698                 } else if (strcmp(symbol->string, "get") == 0) {
2699                         prop = &property->get_symbol;
2700                 } else {
2701                         errorf(HERE, "expected put or get in property declspec");
2702                         prop = NULL;
2703                 }
2704                 eat(T_IDENTIFIER);
2705                 expect('=', end_error);
2706                 if (token.type != T_IDENTIFIER) {
2707                         parse_error_expected("while parsing property declspec",
2708                                              T_IDENTIFIER, NULL);
2709                         goto end_error;
2710                 }
2711                 if (prop != NULL)
2712                         *prop = token.symbol;
2713                 next_token();
2714         } while (next_if(','));
2715
2716         attribute->a.property = property;
2717
2718         expect(')', end_error);
2719
2720 end_error:
2721         return attribute;
2722 }
2723
2724 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2725 {
2726         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2727         if (next_if(T_restrict)) {
2728                 kind = ATTRIBUTE_MS_RESTRICT;
2729         } else if (token.type == T_IDENTIFIER) {
2730                 const char *name = token.symbol->string;
2731                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2732                      ++k) {
2733                         const char *attribute_name = get_attribute_name(k);
2734                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2735                                 kind = k;
2736                                 break;
2737                         }
2738                 }
2739
2740                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2741                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2742                 }
2743                 eat(T_IDENTIFIER);
2744         } else {
2745                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2746                 return NULL;
2747         }
2748
2749         attribute_t *attribute = allocate_attribute_zero(kind);
2750
2751         if (kind == ATTRIBUTE_MS_PROPERTY) {
2752                 return parse_attribute_ms_property(attribute);
2753         }
2754
2755         /* parse arguments */
2756         if (next_if('('))
2757                 attribute->a.arguments = parse_attribute_arguments();
2758
2759         return attribute;
2760 }
2761
2762 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2763 {
2764         eat(T__declspec);
2765
2766         expect('(', end_error);
2767
2768         if (next_if(')'))
2769                 return NULL;
2770
2771         add_anchor_token(')');
2772
2773         attribute_t **anchor = &first;
2774         do {
2775                 while (*anchor != NULL)
2776                         anchor = &(*anchor)->next;
2777
2778                 attribute_t *attribute
2779                         = parse_microsoft_extended_decl_modifier_single();
2780                 if (attribute == NULL)
2781                         goto end_error;
2782
2783                 *anchor = attribute;
2784                 anchor  = &attribute->next;
2785         } while (next_if(','));
2786
2787         rem_anchor_token(')');
2788         expect(')', end_error);
2789         return first;
2790
2791 end_error:
2792         rem_anchor_token(')');
2793         return first;
2794 }
2795
2796 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2797 {
2798         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol);
2799         entity->base.source_position = *HERE;
2800         if (is_declaration(entity)) {
2801                 entity->declaration.type     = type_error_type;
2802                 entity->declaration.implicit = true;
2803         } else if (kind == ENTITY_TYPEDEF) {
2804                 entity->typedefe.type    = type_error_type;
2805                 entity->typedefe.builtin = true;
2806         }
2807         if (kind != ENTITY_COMPOUND_MEMBER)
2808                 record_entity(entity, false);
2809         return entity;
2810 }
2811
2812 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2813 {
2814         type_t            *type              = NULL;
2815         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2816         unsigned           type_specifiers   = 0;
2817         bool               newtype           = false;
2818         bool               saw_error         = false;
2819         bool               old_gcc_extension = in_gcc_extension;
2820
2821         memset(specifiers, 0, sizeof(*specifiers));
2822         specifiers->source_position = token.source_position;
2823
2824         while (true) {
2825                 specifiers->attributes = parse_attributes(specifiers->attributes);
2826
2827                 switch (token.type) {
2828                 /* storage class */
2829 #define MATCH_STORAGE_CLASS(token, class)                                  \
2830                 case token:                                                        \
2831                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2832                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2833                         }                                                              \
2834                         specifiers->storage_class = class;                             \
2835                         if (specifiers->thread_local)                                  \
2836                                 goto check_thread_storage_class;                           \
2837                         next_token();                                                  \
2838                         break;
2839
2840                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2841                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2842                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2843                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2844                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2845
2846                 case T__declspec:
2847                         specifiers->attributes
2848                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2849                         break;
2850
2851                 case T___thread:
2852                         if (specifiers->thread_local) {
2853                                 errorf(HERE, "duplicate '__thread'");
2854                         } else {
2855                                 specifiers->thread_local = true;
2856 check_thread_storage_class:
2857                                 switch (specifiers->storage_class) {
2858                                         case STORAGE_CLASS_EXTERN:
2859                                         case STORAGE_CLASS_NONE:
2860                                         case STORAGE_CLASS_STATIC:
2861                                                 break;
2862
2863                                                 char const* wrong;
2864                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2865                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2866                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2867 wrong_thread_storage_class:
2868                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2869                                                 break;
2870                                 }
2871                         }
2872                         next_token();
2873                         break;
2874
2875                 /* type qualifiers */
2876 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2877                 case token:                                                     \
2878                         qualifiers |= qualifier;                                    \
2879                         next_token();                                               \
2880                         break
2881
2882                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2883                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2884                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2885                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2886                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2887                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2888                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2889                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2890
2891                 case T___extension__:
2892                         next_token();
2893                         in_gcc_extension = true;
2894                         break;
2895
2896                 /* type specifiers */
2897 #define MATCH_SPECIFIER(token, specifier, name)                         \
2898                 case token:                                                     \
2899                         if (type_specifiers & specifier) {                           \
2900                                 errorf(HERE, "multiple " name " type specifiers given"); \
2901                         } else {                                                    \
2902                                 type_specifiers |= specifier;                           \
2903                         }                                                           \
2904                         next_token();                                               \
2905                         break
2906
2907                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2908                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2909                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2910                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2911                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2912                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2913                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2914                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2915                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2916                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2917                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2918                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2919                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2920                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2921                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2922                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2923                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2924                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2925
2926                 case T_inline:
2927                         next_token();
2928                         specifiers->is_inline = true;
2929                         break;
2930
2931 #if 0
2932                 case T__forceinline:
2933                         next_token();
2934                         specifiers->modifiers |= DM_FORCEINLINE;
2935                         break;
2936 #endif
2937
2938                 case T_long:
2939                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2940                                 errorf(HERE, "too many long type specifiers given");
2941                         } else if (type_specifiers & SPECIFIER_LONG) {
2942                                 type_specifiers |= SPECIFIER_LONG_LONG;
2943                         } else {
2944                                 type_specifiers |= SPECIFIER_LONG;
2945                         }
2946                         next_token();
2947                         break;
2948
2949 #define CHECK_DOUBLE_TYPE()        \
2950                         do { \
2951                         if ( type != NULL)     \
2952                                 errorf(HERE, "multiple data types in declaration specifiers"); \
2953                         } while(0)
2954
2955                 case T_struct:
2956                         CHECK_DOUBLE_TYPE();
2957                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2958
2959                         type->compound.compound = parse_compound_type_specifier(true);
2960                         break;
2961                 case T_union:
2962                         CHECK_DOUBLE_TYPE();
2963                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2964                         type->compound.compound = parse_compound_type_specifier(false);
2965                         break;
2966                 case T_enum:
2967                         CHECK_DOUBLE_TYPE();
2968                         type = parse_enum_specifier();
2969                         break;
2970                 case T___typeof__:
2971                         CHECK_DOUBLE_TYPE();
2972                         type = parse_typeof();
2973                         break;
2974                 case T___builtin_va_list:
2975                         CHECK_DOUBLE_TYPE();
2976                         type = duplicate_type(type_valist);
2977                         next_token();
2978                         break;
2979
2980                 case T_IDENTIFIER: {
2981                         /* only parse identifier if we haven't found a type yet */
2982                         if (type != NULL || type_specifiers != 0) {
2983                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2984                                  * declaration, so it doesn't generate errors about expecting '(' or
2985                                  * '{' later on. */
2986                                 switch (look_ahead(1)->type) {
2987                                         STORAGE_CLASSES
2988                                         TYPE_SPECIFIERS
2989                                         case T_const:
2990                                         case T_restrict:
2991                                         case T_volatile:
2992                                         case T_inline:
2993                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2994                                         case T_IDENTIFIER:
2995                                         case '&':
2996                                         case '*':
2997                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2998                                                 next_token();
2999                                                 continue;
3000
3001                                         default:
3002                                                 goto finish_specifiers;
3003                                 }
3004                         }
3005
3006                         type_t *const typedef_type = get_typedef_type(token.symbol);
3007                         if (typedef_type == NULL) {
3008                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3009                                  * declaration, so it doesn't generate 'implicit int' followed by more
3010                                  * errors later on. */
3011                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3012                                 switch (la1_type) {
3013                                         DECLARATION_START
3014                                         case T_IDENTIFIER:
3015                                         case '&':
3016                                         case '*': {
3017                                                 errorf(HERE, "%K does not name a type", &token);
3018
3019                                                 entity_t *entity =
3020                                                         create_error_entity(token.symbol, ENTITY_TYPEDEF);
3021
3022                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3023                                                 type->typedeft.typedefe = &entity->typedefe;
3024
3025                                                 next_token();
3026                                                 saw_error = true;
3027                                                 continue;
3028                                         }
3029
3030                                         default:
3031                                                 goto finish_specifiers;
3032                                 }
3033                         }
3034
3035                         next_token();
3036                         type = typedef_type;
3037                         break;
3038                 }
3039
3040                 /* function specifier */
3041                 default:
3042                         goto finish_specifiers;
3043                 }
3044         }
3045
3046 finish_specifiers:
3047         specifiers->attributes = parse_attributes(specifiers->attributes);
3048
3049         in_gcc_extension = old_gcc_extension;
3050
3051         if (type == NULL || (saw_error && type_specifiers != 0)) {
3052                 atomic_type_kind_t atomic_type;
3053
3054                 /* match valid basic types */
3055                 switch (type_specifiers) {
3056                 case SPECIFIER_VOID:
3057                         atomic_type = ATOMIC_TYPE_VOID;
3058                         break;
3059                 case SPECIFIER_WCHAR_T:
3060                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3061                         break;
3062                 case SPECIFIER_CHAR:
3063                         atomic_type = ATOMIC_TYPE_CHAR;
3064                         break;
3065                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3066                         atomic_type = ATOMIC_TYPE_SCHAR;
3067                         break;
3068                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3069                         atomic_type = ATOMIC_TYPE_UCHAR;
3070                         break;
3071                 case SPECIFIER_SHORT:
3072                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3073                 case SPECIFIER_SHORT | SPECIFIER_INT:
3074                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3075                         atomic_type = ATOMIC_TYPE_SHORT;
3076                         break;
3077                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3078                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3079                         atomic_type = ATOMIC_TYPE_USHORT;
3080                         break;
3081                 case SPECIFIER_INT:
3082                 case SPECIFIER_SIGNED:
3083                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3084                         atomic_type = ATOMIC_TYPE_INT;
3085                         break;
3086                 case SPECIFIER_UNSIGNED:
3087                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3088                         atomic_type = ATOMIC_TYPE_UINT;
3089                         break;
3090                 case SPECIFIER_LONG:
3091                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3092                 case SPECIFIER_LONG | SPECIFIER_INT:
3093                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3094                         atomic_type = ATOMIC_TYPE_LONG;
3095                         break;
3096                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3097                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3098                         atomic_type = ATOMIC_TYPE_ULONG;
3099                         break;
3100
3101                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3102                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3103                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3104                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3105                         | SPECIFIER_INT:
3106                         atomic_type = ATOMIC_TYPE_LONGLONG;
3107                         goto warn_about_long_long;
3108
3109                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3110                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3111                         | SPECIFIER_INT:
3112                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3113 warn_about_long_long:
3114                         if (warning.long_long) {
3115                                 warningf(&specifiers->source_position,
3116                                          "ISO C90 does not support 'long long'");
3117                         }
3118                         break;
3119
3120                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3121                         atomic_type = unsigned_int8_type_kind;
3122                         break;
3123
3124                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3125                         atomic_type = unsigned_int16_type_kind;
3126                         break;
3127
3128                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3129                         atomic_type = unsigned_int32_type_kind;
3130                         break;
3131
3132                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3133                         atomic_type = unsigned_int64_type_kind;
3134                         break;
3135
3136                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3137                         atomic_type = unsigned_int128_type_kind;
3138                         break;
3139
3140                 case SPECIFIER_INT8:
3141                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3142                         atomic_type = int8_type_kind;
3143                         break;
3144
3145                 case SPECIFIER_INT16:
3146                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3147                         atomic_type = int16_type_kind;
3148                         break;
3149
3150                 case SPECIFIER_INT32:
3151                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3152                         atomic_type = int32_type_kind;
3153                         break;
3154
3155                 case SPECIFIER_INT64:
3156                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3157                         atomic_type = int64_type_kind;
3158                         break;
3159
3160                 case SPECIFIER_INT128:
3161                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3162                         atomic_type = int128_type_kind;
3163                         break;
3164
3165                 case SPECIFIER_FLOAT:
3166                         atomic_type = ATOMIC_TYPE_FLOAT;
3167                         break;
3168                 case SPECIFIER_DOUBLE:
3169                         atomic_type = ATOMIC_TYPE_DOUBLE;
3170                         break;
3171                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3172                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3173                         break;
3174                 case SPECIFIER_BOOL:
3175                         atomic_type = ATOMIC_TYPE_BOOL;
3176                         break;
3177                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3178                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3179                         atomic_type = ATOMIC_TYPE_FLOAT;
3180                         break;
3181                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3182                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3183                         atomic_type = ATOMIC_TYPE_DOUBLE;
3184                         break;
3185                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3186                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3187                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3188                         break;
3189                 default: {
3190                         /* invalid specifier combination, give an error message */
3191                         source_position_t const* const pos = &specifiers->source_position;
3192                         if (type_specifiers == 0) {
3193                                 if (!saw_error) {
3194                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3195                                         if (!(c_mode & _CXX) && !strict_mode) {
3196                                                 if (warning.implicit_int) {
3197                                                         warningf(pos, "no type specifiers in declaration, using 'int'");
3198                                                 }
3199                                                 atomic_type = ATOMIC_TYPE_INT;
3200                                                 break;
3201                                         } else {
3202                                                 errorf(pos, "no type specifiers given in declaration");
3203                                         }
3204                                 }
3205                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3206                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3207                                 errorf(pos, "signed and unsigned specifiers given");
3208                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3209                                 errorf(pos, "only integer types can be signed or unsigned");
3210                         } else {
3211                                 errorf(pos, "multiple datatypes in declaration");
3212                         }
3213                         goto end_error;
3214                 }
3215                 }
3216
3217                 if (type_specifiers & SPECIFIER_COMPLEX) {
3218                         type                = allocate_type_zero(TYPE_COMPLEX);
3219                         type->complex.akind = atomic_type;
3220                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3221                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3222                         type->imaginary.akind = atomic_type;
3223                 } else {
3224                         type                 = allocate_type_zero(TYPE_ATOMIC);
3225                         type->atomic.akind   = atomic_type;
3226                 }
3227                 newtype = true;
3228         } else if (type_specifiers != 0) {
3229                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3230         }
3231
3232         /* FIXME: check type qualifiers here */
3233         type->base.qualifiers = qualifiers;
3234
3235         if (newtype) {
3236                 type = identify_new_type(type);
3237         } else {
3238                 type = typehash_insert(type);
3239         }
3240
3241         if (specifiers->attributes != NULL)
3242                 type = handle_type_attributes(specifiers->attributes, type);
3243         specifiers->type = type;
3244         return;
3245
3246 end_error:
3247         specifiers->type = type_error_type;
3248 }
3249
3250 static type_qualifiers_t parse_type_qualifiers(void)
3251 {
3252         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3253
3254         while (true) {
3255                 switch (token.type) {
3256                 /* type qualifiers */
3257                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3258                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3259                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3260                 /* microsoft extended type modifiers */
3261                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3262                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3263                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3264                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3265                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3266
3267                 default:
3268                         return qualifiers;
3269                 }
3270         }
3271 }
3272
3273 /**
3274  * Parses an K&R identifier list
3275  */
3276 static void parse_identifier_list(scope_t *scope)
3277 {
3278         do {
3279                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.symbol);
3280                 entity->base.source_position = token.source_position;
3281                 /* a K&R parameter has no type, yet */
3282                 next_token();
3283
3284                 if (scope != NULL)
3285                         append_entity(scope, entity);
3286         } while (next_if(',') && token.type == T_IDENTIFIER);
3287 }
3288
3289 static entity_t *parse_parameter(void)
3290 {
3291         declaration_specifiers_t specifiers;
3292         parse_declaration_specifiers(&specifiers);
3293
3294         entity_t *entity = parse_declarator(&specifiers,
3295                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3296         anonymous_entity = NULL;
3297         return entity;
3298 }
3299
3300 static void semantic_parameter_incomplete(const entity_t *entity)
3301 {
3302         assert(entity->kind == ENTITY_PARAMETER);
3303
3304         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3305          *             list in a function declarator that is part of a
3306          *             definition of that function shall not have
3307          *             incomplete type. */
3308         type_t *type = skip_typeref(entity->declaration.type);
3309         if (is_type_incomplete(type)) {
3310                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3311         }
3312 }
3313
3314 static bool has_parameters(void)
3315 {
3316         /* func(void) is not a parameter */
3317         if (token.type == T_IDENTIFIER) {
3318                 entity_t const *const entity = get_entity(token.symbol, NAMESPACE_NORMAL);
3319                 if (entity == NULL)
3320                         return true;
3321                 if (entity->kind != ENTITY_TYPEDEF)
3322                         return true;
3323                 if (skip_typeref(entity->typedefe.type) != type_void)
3324                         return true;
3325         } else if (token.type != T_void) {
3326                 return true;
3327         }
3328         if (look_ahead(1)->type != ')')
3329                 return true;
3330         next_token();
3331         return false;
3332 }
3333
3334 /**
3335  * Parses function type parameters (and optionally creates variable_t entities
3336  * for them in a scope)
3337  */
3338 static void parse_parameters(function_type_t *type, scope_t *scope)
3339 {
3340         eat('(');
3341         add_anchor_token(')');
3342         int saved_comma_state = save_and_reset_anchor_state(',');
3343
3344         if (token.type == T_IDENTIFIER &&
3345             !is_typedef_symbol(token.symbol)) {
3346                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3347                 if (la1_type == ',' || la1_type == ')') {
3348                         type->kr_style_parameters = true;
3349                         parse_identifier_list(scope);
3350                         goto parameters_finished;
3351                 }
3352         }
3353
3354         if (token.type == ')') {
3355                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3356                 if (!(c_mode & _CXX))
3357                         type->unspecified_parameters = true;
3358         } else if (has_parameters()) {
3359                 function_parameter_t **anchor = &type->parameters;
3360                 do {
3361                         switch (token.type) {
3362                         case T_DOTDOTDOT:
3363                                 next_token();
3364                                 type->variadic = true;
3365                                 goto parameters_finished;
3366
3367                         case T_IDENTIFIER:
3368                         case T___extension__:
3369                         DECLARATION_START
3370                         {
3371                                 entity_t *entity = parse_parameter();
3372                                 if (entity->kind == ENTITY_TYPEDEF) {
3373                                         errorf(&entity->base.source_position,
3374                                                         "typedef not allowed as function parameter");
3375                                         break;
3376                                 }
3377                                 assert(is_declaration(entity));
3378
3379                                 semantic_parameter_incomplete(entity);
3380
3381                                 function_parameter_t *const parameter =
3382                                         allocate_parameter(entity->declaration.type);
3383
3384                                 if (scope != NULL) {
3385                                         append_entity(scope, entity);
3386                                 }
3387
3388                                 *anchor = parameter;
3389                                 anchor  = &parameter->next;
3390                                 break;
3391                         }
3392
3393                         default:
3394                                 goto parameters_finished;
3395                         }
3396                 } while (next_if(','));
3397         }
3398
3399 parameters_finished:
3400         rem_anchor_token(')');
3401         expect(')', end_error);
3402
3403 end_error:
3404         restore_anchor_state(',', saved_comma_state);
3405 }
3406
3407 typedef enum construct_type_kind_t {
3408         CONSTRUCT_INVALID,
3409         CONSTRUCT_POINTER,
3410         CONSTRUCT_REFERENCE,
3411         CONSTRUCT_FUNCTION,
3412         CONSTRUCT_ARRAY
3413 } construct_type_kind_t;
3414
3415 typedef union construct_type_t construct_type_t;
3416
3417 typedef struct construct_type_base_t {
3418         construct_type_kind_t  kind;
3419         source_position_t      pos;
3420         construct_type_t      *next;
3421 } construct_type_base_t;
3422
3423 typedef struct parsed_pointer_t {
3424         construct_type_base_t  base;
3425         type_qualifiers_t      type_qualifiers;
3426         variable_t            *base_variable;  /**< MS __based extension. */
3427 } parsed_pointer_t;
3428
3429 typedef struct parsed_reference_t {
3430         construct_type_base_t base;
3431 } parsed_reference_t;
3432
3433 typedef struct construct_function_type_t {
3434         construct_type_base_t  base;
3435         type_t                *function_type;
3436 } construct_function_type_t;
3437
3438 typedef struct parsed_array_t {
3439         construct_type_base_t  base;
3440         type_qualifiers_t      type_qualifiers;
3441         bool                   is_static;
3442         bool                   is_variable;
3443         expression_t          *size;
3444 } parsed_array_t;
3445
3446 union construct_type_t {
3447         construct_type_kind_t     kind;
3448         construct_type_base_t     base;
3449         parsed_pointer_t          pointer;
3450         parsed_reference_t        reference;
3451         construct_function_type_t function;
3452         parsed_array_t            array;
3453 };
3454
3455 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3456 {
3457         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3458         memset(cons, 0, size);
3459         cons->kind     = kind;
3460         cons->base.pos = *HERE;
3461         return cons;
3462 }
3463
3464 /* §6.7.5.1 */
3465 static construct_type_t *parse_pointer_declarator(void)
3466 {
3467         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3468         eat('*');
3469         cons->pointer.type_qualifiers = parse_type_qualifiers();
3470         //cons->pointer.base_variable   = base_variable;
3471
3472         return cons;
3473 }
3474
3475 /* ISO/IEC 14882:1998(E) §8.3.2 */
3476 static construct_type_t *parse_reference_declarator(void)
3477 {
3478         if (!(c_mode & _CXX))
3479                 errorf(HERE, "references are only available for C++");
3480
3481         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3482         eat('&');
3483
3484         return cons;
3485 }
3486
3487 /* §6.7.5.2 */
3488 static construct_type_t *parse_array_declarator(void)
3489 {
3490         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3491         parsed_array_t   *const array = &cons->array;
3492
3493         eat('[');
3494         add_anchor_token(']');
3495
3496         bool is_static = next_if(T_static);
3497
3498         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3499
3500         if (!is_static)
3501                 is_static = next_if(T_static);
3502
3503         array->type_qualifiers = type_qualifiers;
3504         array->is_static       = is_static;
3505
3506         expression_t *size = NULL;
3507         if (token.type == '*' && look_ahead(1)->type == ']') {
3508                 array->is_variable = true;
3509                 next_token();
3510         } else if (token.type != ']') {
3511                 size = parse_assignment_expression();
3512
3513                 /* §6.7.5.2:1  Array size must have integer type */
3514                 type_t *const orig_type = size->base.type;
3515                 type_t *const type      = skip_typeref(orig_type);
3516                 if (!is_type_integer(type) && is_type_valid(type)) {
3517                         errorf(&size->base.source_position,
3518                                "array size '%E' must have integer type but has type '%T'",
3519                                size, orig_type);
3520                 }
3521
3522                 array->size = size;
3523                 mark_vars_read(size, NULL);
3524         }
3525
3526         if (is_static && size == NULL)
3527                 errorf(&array->base.pos, "static array parameters require a size");
3528
3529         rem_anchor_token(']');
3530         expect(']', end_error);
3531
3532 end_error:
3533         return cons;
3534 }
3535
3536 /* §6.7.5.3 */
3537 static construct_type_t *parse_function_declarator(scope_t *scope)
3538 {
3539         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3540
3541         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3542         function_type_t *ftype = &type->function;
3543
3544         ftype->linkage            = current_linkage;
3545         ftype->calling_convention = CC_DEFAULT;
3546
3547         parse_parameters(ftype, scope);
3548
3549         cons->function.function_type = type;
3550
3551         return cons;
3552 }
3553
3554 typedef struct parse_declarator_env_t {
3555         bool               may_be_abstract : 1;
3556         bool               must_be_abstract : 1;
3557         decl_modifiers_t   modifiers;
3558         symbol_t          *symbol;
3559         source_position_t  source_position;
3560         scope_t            parameters;
3561         attribute_t       *attributes;
3562 } parse_declarator_env_t;
3563
3564 /* §6.7.5 */
3565 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3566 {
3567         /* construct a single linked list of construct_type_t's which describe
3568          * how to construct the final declarator type */
3569         construct_type_t  *first      = NULL;
3570         construct_type_t **anchor     = &first;
3571
3572         env->attributes = parse_attributes(env->attributes);
3573
3574         for (;;) {
3575                 construct_type_t *type;
3576                 //variable_t       *based = NULL; /* MS __based extension */
3577                 switch (token.type) {
3578                         case '&':
3579                                 type = parse_reference_declarator();
3580                                 break;
3581
3582                         case T__based: {
3583                                 panic("based not supported anymore");
3584                                 /* FALLTHROUGH */
3585                         }
3586
3587                         case '*':
3588                                 type = parse_pointer_declarator();
3589                                 break;
3590
3591                         default:
3592                                 goto ptr_operator_end;
3593                 }
3594
3595                 *anchor = type;
3596                 anchor  = &type->base.next;
3597
3598                 /* TODO: find out if this is correct */
3599                 env->attributes = parse_attributes(env->attributes);
3600         }
3601
3602 ptr_operator_end: ;
3603         construct_type_t *inner_types = NULL;
3604
3605         switch (token.type) {
3606         case T_IDENTIFIER:
3607                 if (env->must_be_abstract) {
3608                         errorf(HERE, "no identifier expected in typename");
3609                 } else {
3610                         env->symbol          = token.symbol;
3611                         env->source_position = token.source_position;
3612                 }
3613                 next_token();
3614                 break;
3615
3616         case '(': {
3617                 /* Parenthesized declarator or function declarator? */
3618                 token_t const *const la1 = look_ahead(1);
3619                 switch (la1->type) {
3620                         case T_IDENTIFIER:
3621                                 if (is_typedef_symbol(la1->symbol)) {
3622                         case ')':
3623                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3624                                          * interpreted as ``function with no parameter specification'', rather
3625                                          * than redundant parentheses around the omitted identifier. */
3626                         default:
3627                                         /* Function declarator. */
3628                                         if (!env->may_be_abstract) {
3629                                                 errorf(HERE, "function declarator must have a name");
3630                                         }
3631                                 } else {
3632                         case '&':
3633                         case '(':
3634                         case '*':
3635                         case '[':
3636                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3637                                         /* Paranthesized declarator. */
3638                                         next_token();
3639                                         add_anchor_token(')');
3640                                         inner_types = parse_inner_declarator(env);
3641                                         if (inner_types != NULL) {
3642                                                 /* All later declarators only modify the return type */
3643                                                 env->must_be_abstract = true;
3644                                         }
3645                                         rem_anchor_token(')');
3646                                         expect(')', end_error);
3647                                 }
3648                                 break;
3649                 }
3650                 break;
3651         }
3652
3653         default:
3654                 if (env->may_be_abstract)
3655                         break;
3656                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3657                 eat_until_anchor();
3658                 return NULL;
3659         }
3660
3661         construct_type_t **const p = anchor;
3662
3663         for (;;) {
3664                 construct_type_t *type;
3665                 switch (token.type) {
3666                 case '(': {
3667                         scope_t *scope = NULL;
3668                         if (!env->must_be_abstract) {
3669                                 scope = &env->parameters;
3670                         }
3671
3672                         type = parse_function_declarator(scope);
3673                         break;
3674                 }
3675                 case '[':
3676                         type = parse_array_declarator();
3677                         break;
3678                 default:
3679                         goto declarator_finished;
3680                 }
3681
3682                 /* insert in the middle of the list (at p) */
3683                 type->base.next = *p;
3684                 *p              = type;
3685                 if (anchor == p)
3686                         anchor = &type->base.next;
3687         }
3688
3689 declarator_finished:
3690         /* append inner_types at the end of the list, we don't to set anchor anymore
3691          * as it's not needed anymore */
3692         *anchor = inner_types;
3693
3694         return first;
3695 end_error:
3696         return NULL;
3697 }
3698
3699 static type_t *construct_declarator_type(construct_type_t *construct_list,
3700                                          type_t *type)
3701 {
3702         construct_type_t *iter = construct_list;
3703         for (; iter != NULL; iter = iter->base.next) {
3704                 source_position_t const* const pos = &iter->base.pos;
3705                 switch (iter->kind) {
3706                 case CONSTRUCT_INVALID:
3707                         break;
3708                 case CONSTRUCT_FUNCTION: {
3709                         construct_function_type_t *function      = &iter->function;
3710                         type_t                    *function_type = function->function_type;
3711
3712                         function_type->function.return_type = type;
3713
3714                         type_t *skipped_return_type = skip_typeref(type);
3715                         /* §6.7.5.3:1 */
3716                         if (is_type_function(skipped_return_type)) {
3717                                 errorf(pos, "function returning function is not allowed");
3718                         } else if (is_type_array(skipped_return_type)) {
3719                                 errorf(pos, "function returning array is not allowed");
3720                         } else {
3721                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3722                                         warningf(pos, "type qualifiers in return type of function type are meaningless");
3723                                 }
3724                         }
3725
3726                         /* The function type was constructed earlier.  Freeing it here will
3727                          * destroy other types. */
3728                         type = typehash_insert(function_type);
3729                         continue;
3730                 }
3731
3732                 case CONSTRUCT_POINTER: {
3733                         if (is_type_reference(skip_typeref(type)))
3734                                 errorf(pos, "cannot declare a pointer to reference");
3735
3736                         parsed_pointer_t *pointer = &iter->pointer;
3737                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3738                         continue;
3739                 }
3740
3741                 case CONSTRUCT_REFERENCE:
3742                         if (is_type_reference(skip_typeref(type)))
3743                                 errorf(pos, "cannot declare a reference to reference");
3744
3745                         type = make_reference_type(type);
3746                         continue;
3747
3748                 case CONSTRUCT_ARRAY: {
3749                         if (is_type_reference(skip_typeref(type)))
3750                                 errorf(pos, "cannot declare an array of references");
3751
3752                         parsed_array_t *array      = &iter->array;
3753                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3754
3755                         expression_t *size_expression = array->size;
3756                         if (size_expression != NULL) {
3757                                 size_expression
3758                                         = create_implicit_cast(size_expression, type_size_t);
3759                         }
3760
3761                         array_type->base.qualifiers       = array->type_qualifiers;
3762                         array_type->array.element_type    = type;
3763                         array_type->array.is_static       = array->is_static;
3764                         array_type->array.is_variable     = array->is_variable;
3765                         array_type->array.size_expression = size_expression;
3766
3767                         if (size_expression != NULL) {
3768                                 switch (is_constant_expression(size_expression)) {
3769                                 case EXPR_CLASS_CONSTANT: {
3770                                         long const size = fold_constant_to_int(size_expression);
3771                                         array_type->array.size          = size;
3772                                         array_type->array.size_constant = true;
3773                                         /* §6.7.5.2:1  If the expression is a constant expression,
3774                                          * it shall have a value greater than zero. */
3775                                         if (size < 0) {
3776                                                 errorf(&size_expression->base.source_position,
3777                                                            "size of array must be greater than zero");
3778                                         } else if (size == 0 && !GNU_MODE) {
3779                                                 errorf(&size_expression->base.source_position,
3780                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3781                                         }
3782                                         break;
3783                                 }
3784
3785                                 case EXPR_CLASS_VARIABLE:
3786                                         array_type->array.is_vla = true;
3787                                         break;
3788
3789                                 case EXPR_CLASS_ERROR:
3790                                         break;
3791                                 }
3792                         }
3793
3794                         type_t *skipped_type = skip_typeref(type);
3795                         /* §6.7.5.2:1 */
3796                         if (is_type_incomplete(skipped_type)) {
3797                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3798                         } else if (is_type_function(skipped_type)) {
3799                                 errorf(pos, "array of functions is not allowed");
3800                         }
3801                         type = identify_new_type(array_type);
3802                         continue;
3803                 }
3804                 }
3805                 internal_errorf(pos, "invalid type construction found");
3806         }
3807
3808         return type;
3809 }
3810
3811 static type_t *automatic_type_conversion(type_t *orig_type);
3812
3813 static type_t *semantic_parameter(const source_position_t *pos,
3814                                   type_t *type,
3815                                   const declaration_specifiers_t *specifiers,
3816                                   entity_t const *const param)
3817 {
3818         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3819          *             shall be adjusted to ``qualified pointer to type'',
3820          *             [...]
3821          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3822          *             type'' shall be adjusted to ``pointer to function
3823          *             returning type'', as in 6.3.2.1. */
3824         type = automatic_type_conversion(type);
3825
3826         if (specifiers->is_inline && is_type_valid(type)) {
3827                 errorf(pos, "'%N' declared 'inline'", param);
3828         }
3829
3830         /* §6.9.1:6  The declarations in the declaration list shall contain
3831          *           no storage-class specifier other than register and no
3832          *           initializations. */
3833         if (specifiers->thread_local || (
3834                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3835                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3836            ) {
3837                 errorf(pos, "invalid storage class for '%N'", param);
3838         }
3839
3840         /* delay test for incomplete type, because we might have (void)
3841          * which is legal but incomplete... */
3842
3843         return type;
3844 }
3845
3846 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3847                                   declarator_flags_t flags)
3848 {
3849         parse_declarator_env_t env;
3850         memset(&env, 0, sizeof(env));
3851         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3852
3853         construct_type_t *construct_type = parse_inner_declarator(&env);
3854         type_t           *orig_type      =
3855                 construct_declarator_type(construct_type, specifiers->type);
3856         type_t           *type           = skip_typeref(orig_type);
3857
3858         if (construct_type != NULL) {
3859                 obstack_free(&temp_obst, construct_type);
3860         }
3861
3862         attribute_t *attributes = parse_attributes(env.attributes);
3863         /* append (shared) specifier attribute behind attributes of this
3864          * declarator */
3865         attribute_t **anchor = &attributes;
3866         while (*anchor != NULL)
3867                 anchor = &(*anchor)->next;
3868         *anchor = specifiers->attributes;
3869
3870         entity_t *entity;
3871         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3872                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol);
3873                 entity->base.source_position = env.source_position;
3874                 entity->typedefe.type        = orig_type;
3875
3876                 if (anonymous_entity != NULL) {
3877                         if (is_type_compound(type)) {
3878                                 assert(anonymous_entity->compound.alias == NULL);
3879                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3880                                        anonymous_entity->kind == ENTITY_UNION);
3881                                 anonymous_entity->compound.alias = entity;
3882                                 anonymous_entity = NULL;
3883                         } else if (is_type_enum(type)) {
3884                                 assert(anonymous_entity->enume.alias == NULL);
3885                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3886                                 anonymous_entity->enume.alias = entity;
3887                                 anonymous_entity = NULL;
3888                         }
3889                 }
3890         } else {
3891                 /* create a declaration type entity */
3892                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3893                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol);
3894
3895                         if (env.symbol != NULL) {
3896                                 if (specifiers->is_inline && is_type_valid(type)) {
3897                                         errorf(&env.source_position,
3898                                                         "compound member '%Y' declared 'inline'", env.symbol);
3899                                 }
3900
3901                                 if (specifiers->thread_local ||
3902                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3903                                         errorf(&env.source_position,
3904                                                         "compound member '%Y' must have no storage class",
3905                                                         env.symbol);
3906                                 }
3907                         }
3908                 } else if (flags & DECL_IS_PARAMETER) {
3909                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol);
3910                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3911                 } else if (is_type_function(type)) {
3912                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol);
3913                         entity->function.is_inline      = specifiers->is_inline;
3914                         entity->function.elf_visibility = default_visibility;
3915                         entity->function.parameters     = env.parameters;
3916
3917                         if (env.symbol != NULL) {
3918                                 /* this needs fixes for C++ */
3919                                 bool in_function_scope = current_function != NULL;
3920
3921                                 if (specifiers->thread_local || (
3922                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3923                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3924                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3925                                                 )) {
3926                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3927                                 }
3928                         }
3929                 } else {
3930                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol);
3931                         entity->variable.elf_visibility = default_visibility;
3932                         entity->variable.thread_local   = specifiers->thread_local;
3933
3934                         if (env.symbol != NULL) {
3935                                 if (specifiers->is_inline && is_type_valid(type)) {
3936                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3937                                 }
3938
3939                                 bool invalid_storage_class = false;
3940                                 if (current_scope == file_scope) {
3941                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3942                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3943                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3944                                                 invalid_storage_class = true;
3945                                         }
3946                                 } else {
3947                                         if (specifiers->thread_local &&
3948                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3949                                                 invalid_storage_class = true;
3950                                         }
3951                                 }
3952                                 if (invalid_storage_class) {
3953                                         errorf(&env.source_position, "invalid storage class for variable '%N'", entity);
3954                                 }
3955                         }
3956                 }
3957
3958                 entity->base.source_position   = env.symbol != NULL ? env.source_position : specifiers->source_position;
3959                 entity->declaration.type       = orig_type;
3960                 entity->declaration.alignment  = get_type_alignment(orig_type);
3961                 entity->declaration.modifiers  = env.modifiers;
3962                 entity->declaration.attributes = attributes;
3963
3964                 storage_class_t storage_class = specifiers->storage_class;
3965                 entity->declaration.declared_storage_class = storage_class;
3966
3967                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3968                         storage_class = STORAGE_CLASS_AUTO;
3969                 entity->declaration.storage_class = storage_class;
3970         }
3971
3972         if (attributes != NULL) {
3973                 handle_entity_attributes(attributes, entity);
3974         }
3975
3976         return entity;
3977 }
3978
3979 static type_t *parse_abstract_declarator(type_t *base_type)
3980 {
3981         parse_declarator_env_t env;
3982         memset(&env, 0, sizeof(env));
3983         env.may_be_abstract = true;
3984         env.must_be_abstract = true;
3985
3986         construct_type_t *construct_type = parse_inner_declarator(&env);
3987
3988         type_t *result = construct_declarator_type(construct_type, base_type);
3989         if (construct_type != NULL) {
3990                 obstack_free(&temp_obst, construct_type);
3991         }
3992         result = handle_type_attributes(env.attributes, result);
3993
3994         return result;
3995 }
3996
3997 /**
3998  * Check if the declaration of main is suspicious.  main should be a
3999  * function with external linkage, returning int, taking either zero
4000  * arguments, two, or three arguments of appropriate types, ie.
4001  *
4002  * int main([ int argc, char **argv [, char **env ] ]).
4003  *
4004  * @param decl    the declaration to check
4005  * @param type    the function type of the declaration
4006  */
4007 static void check_main(const entity_t *entity)
4008 {
4009         const source_position_t *pos = &entity->base.source_position;
4010         if (entity->kind != ENTITY_FUNCTION) {
4011                 warningf(pos, "'main' is not a function");
4012                 return;
4013         }
4014
4015         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4016                 warningf(pos, "'main' is normally a non-static function");
4017         }
4018
4019         type_t *type = skip_typeref(entity->declaration.type);
4020         assert(is_type_function(type));
4021
4022         function_type_t *func_type = &type->function;
4023         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4024                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4025                          func_type->return_type);
4026         }
4027         const function_parameter_t *parm = func_type->parameters;
4028         if (parm != NULL) {
4029                 type_t *const first_type        = skip_typeref(parm->type);
4030                 type_t *const first_type_unqual = get_unqualified_type(first_type);
4031                 if (!types_compatible(first_type_unqual, type_int)) {
4032                         warningf(pos,
4033                                  "first argument of 'main' should be 'int', but is '%T'",
4034                                  parm->type);
4035                 }
4036                 parm = parm->next;
4037                 if (parm != NULL) {
4038                         type_t *const second_type = skip_typeref(parm->type);
4039                         type_t *const second_type_unqual
4040                                 = get_unqualified_type(second_type);
4041                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
4042                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'",
4043                                          parm->type);
4044                         }
4045                         parm = parm->next;
4046                         if (parm != NULL) {
4047                                 type_t *const third_type = skip_typeref(parm->type);
4048                                 type_t *const third_type_unqual
4049                                         = get_unqualified_type(third_type);
4050                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
4051                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'",
4052                                                  parm->type);
4053                                 }
4054                                 parm = parm->next;
4055                                 if (parm != NULL)
4056                                         goto warn_arg_count;
4057                         }
4058                 } else {
4059 warn_arg_count:
4060                         warningf(pos, "'main' takes only zero, two or three arguments");
4061                 }
4062         }
4063 }
4064
4065 /**
4066  * Check if a symbol is the equal to "main".
4067  */
4068 static bool is_sym_main(const symbol_t *const sym)
4069 {
4070         return strcmp(sym->string, "main") == 0;
4071 }
4072
4073 static void error_redefined_as_different_kind(const source_position_t *pos,
4074                 const entity_t *old, entity_kind_t new_kind)
4075 {
4076         char              const *const what = get_entity_kind_name(new_kind);
4077         source_position_t const *const ppos = &old->base.source_position;
4078         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
4079 }
4080
4081 static bool is_entity_valid(entity_t *const ent)
4082 {
4083         if (is_declaration(ent)) {
4084                 return is_type_valid(skip_typeref(ent->declaration.type));
4085         } else if (ent->kind == ENTITY_TYPEDEF) {
4086                 return is_type_valid(skip_typeref(ent->typedefe.type));
4087         }
4088         return true;
4089 }
4090
4091 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
4092 {
4093         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
4094                 if (attributes_equal(tattr, attr))
4095                         return true;
4096         }
4097         return false;
4098 }
4099
4100 /**
4101  * test wether new_list contains any attributes not included in old_list
4102  */
4103 static bool has_new_attributes(const attribute_t *old_list,
4104                                const attribute_t *new_list)
4105 {
4106         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
4107                 if (!contains_attribute(old_list, attr))
4108                         return true;
4109         }
4110         return false;
4111 }
4112
4113 /**
4114  * Merge in attributes from an attribute list (probably from a previous
4115  * declaration with the same name). Warning: destroys the old structure
4116  * of the attribute list - don't reuse attributes after this call.
4117  */
4118 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4119 {
4120         attribute_t *next;
4121         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4122                 next = attr->next;
4123                 if (contains_attribute(decl->attributes, attr))
4124                         continue;
4125
4126                 /* move attribute to new declarations attributes list */
4127                 attr->next       = decl->attributes;
4128                 decl->attributes = attr;
4129         }
4130 }
4131
4132 /**
4133  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4134  * for various problems that occur for multiple definitions
4135  */
4136 entity_t *record_entity(entity_t *entity, const bool is_definition)
4137 {
4138         const symbol_t *const    symbol  = entity->base.symbol;
4139         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4140         const source_position_t *pos     = &entity->base.source_position;
4141
4142         /* can happen in error cases */
4143         if (symbol == NULL)
4144                 return entity;
4145
4146         entity_t *const previous_entity = get_entity(symbol, namespc);
4147         /* pushing the same entity twice will break the stack structure */
4148         assert(previous_entity != entity);
4149
4150         if (entity->kind == ENTITY_FUNCTION) {
4151                 type_t *const orig_type = entity->declaration.type;
4152                 type_t *const type      = skip_typeref(orig_type);
4153
4154                 assert(is_type_function(type));
4155                 if (type->function.unspecified_parameters &&
4156                                 warning.strict_prototypes &&
4157                                 previous_entity == NULL) {
4158                         warningf(pos, "function declaration '%#N' is not a prototype", entity);
4159                 }
4160
4161                 if (warning.main && current_scope == file_scope
4162                                 && is_sym_main(symbol)) {
4163                         check_main(entity);
4164                 }
4165         }
4166
4167         if (is_declaration(entity) &&
4168                         warning.nested_externs &&
4169                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4170                         current_scope != file_scope) {
4171                 warningf(pos, "nested extern declaration of '%#N'", entity);
4172         }
4173
4174         if (previous_entity != NULL) {
4175                 source_position_t const *const ppos = &previous_entity->base.source_position;
4176
4177                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4178                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4179                         assert(previous_entity->kind == ENTITY_PARAMETER);
4180                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
4181                         goto finish;
4182                 }
4183
4184                 if (previous_entity->base.parent_scope == current_scope) {
4185                         if (previous_entity->kind != entity->kind) {
4186                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4187                                         error_redefined_as_different_kind(pos, previous_entity,
4188                                                         entity->kind);
4189                                 }
4190                                 goto finish;
4191                         }
4192                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4193                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4194                                 goto finish;
4195                         }
4196                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4197                                 /* TODO: C++ allows this for exactly the same type */
4198                                 errorf(pos, "redefinition of '%N' (declared %P)", entity, ppos);
4199                                 goto finish;
4200                         }
4201
4202                         /* at this point we should have only VARIABLES or FUNCTIONS */
4203                         assert(is_declaration(previous_entity) && is_declaration(entity));
4204
4205                         declaration_t *const prev_decl = &previous_entity->declaration;
4206                         declaration_t *const decl      = &entity->declaration;
4207
4208                         /* can happen for K&R style declarations */
4209                         if (prev_decl->type       == NULL             &&
4210                                         previous_entity->kind == ENTITY_PARAMETER &&
4211                                         entity->kind          == ENTITY_PARAMETER) {
4212                                 prev_decl->type                   = decl->type;
4213                                 prev_decl->storage_class          = decl->storage_class;
4214                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4215                                 prev_decl->modifiers              = decl->modifiers;
4216                                 return previous_entity;
4217                         }
4218
4219                         type_t *const type      = skip_typeref(decl->type);
4220                         type_t *const prev_type = skip_typeref(prev_decl->type);
4221
4222                         if (!types_compatible(type, prev_type)) {
4223                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4224                         } else {
4225                                 unsigned old_storage_class = prev_decl->storage_class;
4226
4227                                 if (warning.redundant_decls               &&
4228                                                 is_definition                     &&
4229                                                 !prev_decl->used                  &&
4230                                                 !(prev_decl->modifiers & DM_USED) &&
4231                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4232                                         warningf(ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4233                                 }
4234
4235                                 storage_class_t new_storage_class = decl->storage_class;
4236
4237                                 /* pretend no storage class means extern for function
4238                                  * declarations (except if the previous declaration is neither
4239                                  * none nor extern) */
4240                                 if (entity->kind == ENTITY_FUNCTION) {
4241                                         /* the previous declaration could have unspecified parameters or
4242                                          * be a typedef, so use the new type */
4243                                         if (prev_type->function.unspecified_parameters || is_definition)
4244                                                 prev_decl->type = type;
4245
4246                                         switch (old_storage_class) {
4247                                                 case STORAGE_CLASS_NONE:
4248                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4249                                                         /* FALLTHROUGH */
4250
4251                                                 case STORAGE_CLASS_EXTERN:
4252                                                         if (is_definition) {
4253                                                                 if (warning.missing_prototypes &&
4254                                                                                 prev_type->function.unspecified_parameters &&
4255                                                                                 !is_sym_main(symbol)) {
4256                                                                         warningf(pos, "no previous prototype for '%#N'", entity);
4257                                                                 }
4258                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4259                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4260                                                         }
4261                                                         break;
4262
4263                                                 default:
4264                                                         break;
4265                                         }
4266                                 } else if (is_type_incomplete(prev_type)) {
4267                                         prev_decl->type = type;
4268                                 }
4269
4270                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4271                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4272
4273 warn_redundant_declaration: ;
4274                                         bool has_new_attrs
4275                                                 = has_new_attributes(prev_decl->attributes,
4276                                                                      decl->attributes);
4277                                         if (has_new_attrs) {
4278                                                 merge_in_attributes(decl, prev_decl->attributes);
4279                                         } else if (!is_definition        &&
4280                                                         warning.redundant_decls  &&
4281                                                         is_type_valid(prev_type) &&
4282                                                         strcmp(ppos->input_name, "<builtin>") != 0) {
4283                                                 warningf(pos, "redundant declaration for '%Y' (declared %P)", symbol, ppos);
4284                                         }
4285                                 } else if (current_function == NULL) {
4286                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4287                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4288                                                 errorf(pos, "static declaration of '%Y' follows non-static declaration (declared %P)", symbol, ppos);
4289                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4290                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4291                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4292                                         } else {
4293                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4294                                                 if (c_mode & _CXX)
4295                                                         goto error_redeclaration;
4296                                                 goto warn_redundant_declaration;
4297                                         }
4298                                 } else if (is_type_valid(prev_type)) {
4299                                         if (old_storage_class == new_storage_class) {
4300 error_redeclaration:
4301                                                 errorf(pos, "redeclaration of '%Y' (declared %P)", symbol, ppos);
4302                                         } else {
4303                                                 errorf(pos, "redeclaration of '%Y' with different linkage (declared %P)", symbol, ppos);
4304                                         }
4305                                 }
4306                         }
4307
4308                         prev_decl->modifiers |= decl->modifiers;
4309                         if (entity->kind == ENTITY_FUNCTION) {
4310                                 previous_entity->function.is_inline |= entity->function.is_inline;
4311                         }
4312                         return previous_entity;
4313                 }
4314
4315                 if (warning.shadow ||
4316                                 (warning.shadow_local && previous_entity->base.parent_scope != file_scope)) {
4317                         char const *const what = get_entity_kind_name(previous_entity->kind);
4318                         warningf(pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4319                 }
4320         }
4321
4322         if (entity->kind == ENTITY_FUNCTION) {
4323                 if (is_definition &&
4324                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4325                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4326                                 warningf(pos, "no previous prototype for '%#N'", entity);
4327                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4328                                 warningf(pos, "no previous declaration for '%#N'", entity);
4329                         }
4330                 }
4331         } else if (entity->kind == ENTITY_VARIABLE) {
4332                 if (warning.missing_declarations &&
4333               current_scope == file_scope  &&
4334               entity->declaration.storage_class == STORAGE_CLASS_NONE) {
4335                         warningf(pos, "no previous declaration for '%#N'", entity);
4336                 }
4337         }
4338
4339 finish:
4340         assert(entity->base.parent_scope == NULL);
4341         assert(current_scope != NULL);
4342
4343         entity->base.parent_scope = current_scope;
4344         environment_push(entity);
4345         append_entity(current_scope, entity);
4346
4347         return entity;
4348 }
4349
4350 static void parser_error_multiple_definition(entity_t *entity,
4351                 const source_position_t *source_position)
4352 {
4353         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4354                entity->base.symbol, &entity->base.source_position);
4355 }
4356
4357 static bool is_declaration_specifier(const token_t *token)
4358 {
4359         switch (token->type) {
4360                 DECLARATION_START
4361                         return true;
4362                 case T_IDENTIFIER:
4363                         return is_typedef_symbol(token->symbol);
4364
4365                 default:
4366                         return false;
4367         }
4368 }
4369
4370 static void parse_init_declarator_rest(entity_t *entity)
4371 {
4372         type_t *orig_type = type_error_type;
4373
4374         if (entity->base.kind == ENTITY_TYPEDEF) {
4375                 source_position_t const *const pos = &entity->base.source_position;
4376                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4377         } else {
4378                 assert(is_declaration(entity));
4379                 orig_type = entity->declaration.type;
4380         }
4381
4382         type_t *type = skip_typeref(orig_type);
4383
4384         if (entity->kind == ENTITY_VARIABLE
4385                         && entity->variable.initializer != NULL) {
4386                 parser_error_multiple_definition(entity, HERE);
4387         }
4388         eat('=');
4389
4390         declaration_t *const declaration = &entity->declaration;
4391         bool must_be_constant = false;
4392         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4393             entity->base.parent_scope  == file_scope) {
4394                 must_be_constant = true;
4395         }
4396
4397         if (is_type_function(type)) {
4398                 source_position_t const *const pos = &entity->base.source_position;
4399                 errorf(pos, "'%N' is initialized like a variable", entity);
4400                 orig_type = type_error_type;
4401         }
4402
4403         parse_initializer_env_t env;
4404         env.type             = orig_type;
4405         env.must_be_constant = must_be_constant;
4406         env.entity           = entity;
4407         current_init_decl    = entity;
4408
4409         initializer_t *initializer = parse_initializer(&env);
4410         current_init_decl = NULL;
4411
4412         if (entity->kind == ENTITY_VARIABLE) {
4413                 /* §6.7.5:22  array initializers for arrays with unknown size
4414                  * determine the array type size */
4415                 declaration->type            = env.type;
4416                 entity->variable.initializer = initializer;
4417         }
4418 }
4419
4420 /* parse rest of a declaration without any declarator */
4421 static void parse_anonymous_declaration_rest(
4422                 const declaration_specifiers_t *specifiers)
4423 {
4424         eat(';');
4425         anonymous_entity = NULL;
4426
4427         if (warning.other) {
4428                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4429                                 specifiers->thread_local) {
4430                         warningf(&specifiers->source_position,
4431                                  "useless storage class in empty declaration");
4432                 }
4433
4434                 type_t *type = specifiers->type;
4435                 switch (type->kind) {
4436                         case TYPE_COMPOUND_STRUCT:
4437                         case TYPE_COMPOUND_UNION: {
4438                                 if (type->compound.compound->base.symbol == NULL) {
4439                                         warningf(&specifiers->source_position,
4440                                                  "unnamed struct/union that defines no instances");
4441                                 }
4442                                 break;
4443                         }
4444
4445                         case TYPE_ENUM:
4446                                 break;
4447
4448                         default:
4449                                 warningf(&specifiers->source_position, "empty declaration");
4450                                 break;
4451                 }
4452         }
4453 }
4454
4455 static void check_variable_type_complete(entity_t *ent)
4456 {
4457         if (ent->kind != ENTITY_VARIABLE)
4458                 return;
4459
4460         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4461          *         type for the object shall be complete [...] */
4462         declaration_t *decl = &ent->declaration;
4463         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4464                         decl->storage_class == STORAGE_CLASS_STATIC)
4465                 return;
4466
4467         type_t *const type = skip_typeref(decl->type);
4468         if (!is_type_incomplete(type))
4469                 return;
4470
4471         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4472          * are given length one. */
4473         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4474                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4475                 return;
4476         }
4477
4478         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4479 }
4480
4481
4482 static void parse_declaration_rest(entity_t *ndeclaration,
4483                 const declaration_specifiers_t *specifiers,
4484                 parsed_declaration_func         finished_declaration,
4485                 declarator_flags_t              flags)
4486 {
4487         add_anchor_token(';');
4488         add_anchor_token(',');
4489         while (true) {
4490                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4491
4492                 if (token.type == '=') {
4493                         parse_init_declarator_rest(entity);
4494                 } else if (entity->kind == ENTITY_VARIABLE) {
4495                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4496                          * [...] where the extern specifier is explicitly used. */
4497                         declaration_t *decl = &entity->declaration;
4498                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4499                                 type_t *type = decl->type;
4500                                 if (is_type_reference(skip_typeref(type))) {
4501                                         source_position_t const *const pos = &entity->base.source_position;
4502                                         errorf(pos, "reference '%#N' must be initialized", entity);
4503                                 }
4504                         }
4505                 }
4506
4507                 check_variable_type_complete(entity);
4508
4509                 if (!next_if(','))
4510                         break;
4511
4512                 add_anchor_token('=');
4513                 ndeclaration = parse_declarator(specifiers, flags);
4514                 rem_anchor_token('=');
4515         }
4516         expect(';', end_error);
4517
4518 end_error:
4519         anonymous_entity = NULL;
4520         rem_anchor_token(';');
4521         rem_anchor_token(',');
4522 }
4523
4524 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4525 {
4526         symbol_t *symbol = entity->base.symbol;
4527         if (symbol == NULL)
4528                 return entity;
4529
4530         assert(entity->base.namespc == NAMESPACE_NORMAL);
4531         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4532         if (previous_entity == NULL
4533                         || previous_entity->base.parent_scope != current_scope) {
4534                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4535                        symbol);
4536                 return entity;
4537         }
4538
4539         if (is_definition) {
4540                 errorf(HERE, "'%N' is initialised", entity);
4541         }
4542
4543         return record_entity(entity, false);
4544 }
4545
4546 static void parse_declaration(parsed_declaration_func finished_declaration,
4547                               declarator_flags_t      flags)
4548 {
4549         add_anchor_token(';');
4550         declaration_specifiers_t specifiers;
4551         parse_declaration_specifiers(&specifiers);
4552         rem_anchor_token(';');
4553
4554         if (token.type == ';') {
4555                 parse_anonymous_declaration_rest(&specifiers);
4556         } else {
4557                 entity_t *entity = parse_declarator(&specifiers, flags);
4558                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4559         }
4560 }
4561
4562 /* §6.5.2.2:6 */
4563 static type_t *get_default_promoted_type(type_t *orig_type)
4564 {
4565         type_t *result = orig_type;
4566
4567         type_t *type = skip_typeref(orig_type);
4568         if (is_type_integer(type)) {
4569                 result = promote_integer(type);
4570         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4571                 result = type_double;
4572         }
4573
4574         return result;
4575 }
4576
4577 static void parse_kr_declaration_list(entity_t *entity)
4578 {
4579         if (entity->kind != ENTITY_FUNCTION)
4580                 return;
4581
4582         type_t *type = skip_typeref(entity->declaration.type);
4583         assert(is_type_function(type));
4584         if (!type->function.kr_style_parameters)
4585                 return;
4586
4587         add_anchor_token('{');
4588
4589         /* push function parameters */
4590         size_t const  top       = environment_top();
4591         scope_t      *old_scope = scope_push(&entity->function.parameters);
4592
4593         entity_t *parameter = entity->function.parameters.entities;
4594         for ( ; parameter != NULL; parameter = parameter->base.next) {
4595                 assert(parameter->base.parent_scope == NULL);
4596                 parameter->base.parent_scope = current_scope;
4597                 environment_push(parameter);
4598         }
4599
4600         /* parse declaration list */
4601         for (;;) {
4602                 switch (token.type) {
4603                         DECLARATION_START
4604                         case T___extension__:
4605                         /* This covers symbols, which are no type, too, and results in
4606                          * better error messages.  The typical cases are misspelled type
4607                          * names and missing includes. */
4608                         case T_IDENTIFIER:
4609                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4610                                 break;
4611                         default:
4612                                 goto decl_list_end;
4613                 }
4614         }
4615 decl_list_end:
4616
4617         /* pop function parameters */
4618         assert(current_scope == &entity->function.parameters);
4619         scope_pop(old_scope);
4620         environment_pop_to(top);
4621
4622         /* update function type */
4623         type_t *new_type = duplicate_type(type);
4624
4625         function_parameter_t  *parameters = NULL;
4626         function_parameter_t **anchor     = &parameters;
4627
4628         /* did we have an earlier prototype? */
4629         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4630         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4631                 proto_type = NULL;
4632
4633         function_parameter_t *proto_parameter = NULL;
4634         if (proto_type != NULL) {
4635                 type_t *proto_type_type = proto_type->declaration.type;
4636                 proto_parameter         = proto_type_type->function.parameters;
4637                 /* If a K&R function definition has a variadic prototype earlier, then
4638                  * make the function definition variadic, too. This should conform to
4639                  * §6.7.5.3:15 and §6.9.1:8. */
4640                 new_type->function.variadic = proto_type_type->function.variadic;
4641         } else {
4642                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4643                  * prototype */
4644                 new_type->function.unspecified_parameters = true;
4645         }
4646
4647         bool need_incompatible_warning = false;
4648         parameter = entity->function.parameters.entities;
4649         for (; parameter != NULL; parameter = parameter->base.next,
4650                         proto_parameter =
4651                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4652                 if (parameter->kind != ENTITY_PARAMETER)
4653                         continue;
4654
4655                 type_t *parameter_type = parameter->declaration.type;
4656                 if (parameter_type == NULL) {
4657                         source_position_t const* const pos = &parameter->base.source_position;
4658                         if (strict_mode) {
4659                                 errorf(pos, "no type specified for function '%N'", parameter);
4660                                 parameter_type = type_error_type;
4661                         } else {
4662                                 if (warning.implicit_int) {
4663                                         warningf(pos, "no type specified for function '%N', using 'int'", parameter);
4664                                 }
4665                                 parameter_type = type_int;
4666                         }
4667                         parameter->declaration.type = parameter_type;
4668                 }
4669
4670                 semantic_parameter_incomplete(parameter);
4671
4672                 /* we need the default promoted types for the function type */
4673                 type_t *not_promoted = parameter_type;
4674                 parameter_type       = get_default_promoted_type(parameter_type);
4675
4676                 /* gcc special: if the type of the prototype matches the unpromoted
4677                  * type don't promote */
4678                 if (!strict_mode && proto_parameter != NULL) {
4679                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4680                         type_t *promo_skip   = skip_typeref(parameter_type);
4681                         type_t *param_skip   = skip_typeref(not_promoted);
4682                         if (!types_compatible(proto_p_type, promo_skip)
4683                                 && types_compatible(proto_p_type, param_skip)) {
4684                                 /* don't promote */
4685                                 need_incompatible_warning = true;
4686                                 parameter_type = not_promoted;
4687                         }
4688                 }
4689                 function_parameter_t *const function_parameter
4690                         = allocate_parameter(parameter_type);
4691
4692                 *anchor = function_parameter;
4693                 anchor  = &function_parameter->next;
4694         }
4695
4696         new_type->function.parameters = parameters;
4697         new_type = identify_new_type(new_type);
4698
4699         if (warning.other && need_incompatible_warning) {
4700                 source_position_t const *const pos  = &entity->base.source_position;
4701                 source_position_t const *const ppos = &proto_type->base.source_position;
4702                 symbol_t          const *const sym  = entity->base.symbol;
4703                 warningf(pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4704         }
4705         entity->declaration.type = new_type;
4706
4707         rem_anchor_token('{');
4708 }
4709
4710 static bool first_err = true;
4711
4712 /**
4713  * When called with first_err set, prints the name of the current function,
4714  * else does noting.
4715  */
4716 static void print_in_function(void)
4717 {
4718         if (first_err) {
4719                 first_err = false;
4720                 char const *const file = current_function->base.base.source_position.input_name;
4721                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4722         }
4723 }
4724
4725 /**
4726  * Check if all labels are defined in the current function.
4727  * Check if all labels are used in the current function.
4728  */
4729 static void check_labels(void)
4730 {
4731         for (const goto_statement_t *goto_statement = goto_first;
4732             goto_statement != NULL;
4733             goto_statement = goto_statement->next) {
4734                 /* skip computed gotos */
4735                 if (goto_statement->expression != NULL)
4736                         continue;
4737
4738                 label_t *label = goto_statement->label;
4739                 if (label->base.source_position.input_name == NULL) {
4740                         print_in_function();
4741                         source_position_t const *const pos = &goto_statement->base.source_position;
4742                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4743                  }
4744         }
4745
4746         if (warning.unused_label) {
4747                 for (const label_statement_t *label_statement = label_first;
4748                          label_statement != NULL;
4749                          label_statement = label_statement->next) {
4750                         label_t *label = label_statement->label;
4751
4752                         if (! label->used) {
4753                                 print_in_function();
4754                                 source_position_t const *const pos = &label_statement->base.source_position;
4755                                 warningf(pos, "'%N' defined but not used", (entity_t const*)label);
4756                         }
4757                 }
4758         }
4759 }
4760
4761 static void warn_unused_entity(entity_t *entity, entity_t *last)
4762 {
4763         entity_t const *const end = last != NULL ? last->base.next : NULL;
4764         for (; entity != end; entity = entity->base.next) {
4765                 if (!is_declaration(entity))
4766                         continue;
4767
4768                 declaration_t *declaration = &entity->declaration;
4769                 if (declaration->implicit)
4770                         continue;
4771
4772                 if (!declaration->used) {
4773                         print_in_function();
4774                         warningf(&entity->base.source_position, "'%N' is unused", entity);
4775                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4776                         print_in_function();
4777                         warningf(&entity->base.source_position, "'%N' is never read", entity);
4778                 }
4779         }
4780 }
4781
4782 static void check_unused_variables(statement_t *const stmt, void *const env)
4783 {
4784         (void)env;
4785
4786         switch (stmt->kind) {
4787                 case STATEMENT_DECLARATION: {
4788                         declaration_statement_t const *const decls = &stmt->declaration;
4789                         warn_unused_entity(decls->declarations_begin,
4790                                            decls->declarations_end);
4791                         return;
4792                 }
4793
4794                 case STATEMENT_FOR:
4795                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4796                         return;
4797
4798                 default:
4799                         return;
4800         }
4801 }
4802
4803 /**
4804  * Check declarations of current_function for unused entities.
4805  */
4806 static void check_declarations(void)
4807 {
4808         if (warning.unused_parameter) {
4809                 const scope_t *scope = &current_function->parameters;
4810
4811                 /* do not issue unused warnings for main */
4812                 if (!is_sym_main(current_function->base.base.symbol)) {
4813                         warn_unused_entity(scope->entities, NULL);
4814                 }
4815         }
4816         if (warning.unused_variable) {
4817                 walk_statements(current_function->statement, check_unused_variables,
4818                                 NULL);
4819         }
4820 }
4821
4822 static int determine_truth(expression_t const* const cond)
4823 {
4824         return
4825                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4826                 fold_constant_to_bool(cond)                         ? 1 :
4827                 -1;
4828 }
4829
4830 static void check_reachable(statement_t *);
4831 static bool reaches_end;
4832
4833 static bool expression_returns(expression_t const *const expr)
4834 {
4835         switch (expr->kind) {
4836                 case EXPR_CALL: {
4837                         expression_t const *const func = expr->call.function;
4838                         if (func->kind == EXPR_REFERENCE) {
4839                                 entity_t *entity = func->reference.entity;
4840                                 if (entity->kind == ENTITY_FUNCTION
4841                                                 && entity->declaration.modifiers & DM_NORETURN)
4842                                         return false;
4843                         }
4844
4845                         if (!expression_returns(func))
4846                                 return false;
4847
4848                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4849                                 if (!expression_returns(arg->expression))
4850                                         return false;
4851                         }
4852
4853                         return true;
4854                 }
4855
4856                 case EXPR_REFERENCE:
4857                 case EXPR_REFERENCE_ENUM_VALUE:
4858                 EXPR_LITERAL_CASES
4859                 case EXPR_STRING_LITERAL:
4860                 case EXPR_WIDE_STRING_LITERAL:
4861                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4862                 case EXPR_LABEL_ADDRESS:
4863                 case EXPR_CLASSIFY_TYPE:
4864                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4865                 case EXPR_ALIGNOF:
4866                 case EXPR_FUNCNAME:
4867                 case EXPR_BUILTIN_CONSTANT_P:
4868                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4869                 case EXPR_OFFSETOF:
4870                 case EXPR_INVALID:
4871                         return true;
4872
4873                 case EXPR_STATEMENT: {
4874                         bool old_reaches_end = reaches_end;
4875                         reaches_end = false;
4876                         check_reachable(expr->statement.statement);
4877                         bool returns = reaches_end;
4878                         reaches_end = old_reaches_end;
4879                         return returns;
4880                 }
4881
4882                 case EXPR_CONDITIONAL:
4883                         // TODO handle constant expression
4884
4885                         if (!expression_returns(expr->conditional.condition))
4886                                 return false;
4887
4888                         if (expr->conditional.true_expression != NULL
4889                                         && expression_returns(expr->conditional.true_expression))
4890                                 return true;
4891
4892                         return expression_returns(expr->conditional.false_expression);
4893
4894                 case EXPR_SELECT:
4895                         return expression_returns(expr->select.compound);
4896
4897                 case EXPR_ARRAY_ACCESS:
4898                         return
4899                                 expression_returns(expr->array_access.array_ref) &&
4900                                 expression_returns(expr->array_access.index);
4901
4902                 case EXPR_VA_START:
4903                         return expression_returns(expr->va_starte.ap);
4904
4905                 case EXPR_VA_ARG:
4906                         return expression_returns(expr->va_arge.ap);
4907
4908                 case EXPR_VA_COPY:
4909                         return expression_returns(expr->va_copye.src);
4910
4911                 EXPR_UNARY_CASES_MANDATORY
4912                         return expression_returns(expr->unary.value);
4913
4914                 case EXPR_UNARY_THROW:
4915                         return false;
4916
4917                 EXPR_BINARY_CASES
4918                         // TODO handle constant lhs of && and ||
4919                         return
4920                                 expression_returns(expr->binary.left) &&
4921                                 expression_returns(expr->binary.right);
4922
4923                 case EXPR_UNKNOWN:
4924                         break;
4925         }
4926
4927         panic("unhandled expression");
4928 }
4929
4930 static bool initializer_returns(initializer_t const *const init)
4931 {
4932         switch (init->kind) {
4933                 case INITIALIZER_VALUE:
4934                         return expression_returns(init->value.value);
4935
4936                 case INITIALIZER_LIST: {
4937                         initializer_t * const*       i       = init->list.initializers;
4938                         initializer_t * const* const end     = i + init->list.len;
4939                         bool                         returns = true;
4940                         for (; i != end; ++i) {
4941                                 if (!initializer_returns(*i))
4942                                         returns = false;
4943                         }
4944                         return returns;
4945                 }
4946
4947                 case INITIALIZER_STRING:
4948                 case INITIALIZER_WIDE_STRING:
4949                 case INITIALIZER_DESIGNATOR: // designators have no payload
4950                         return true;
4951         }
4952         panic("unhandled initializer");
4953 }
4954
4955 static bool noreturn_candidate;
4956
4957 static void check_reachable(statement_t *const stmt)
4958 {
4959         if (stmt->base.reachable)
4960                 return;
4961         if (stmt->kind != STATEMENT_DO_WHILE)
4962                 stmt->base.reachable = true;
4963
4964         statement_t *last = stmt;
4965         statement_t *next;
4966         switch (stmt->kind) {
4967                 case STATEMENT_INVALID:
4968                 case STATEMENT_EMPTY:
4969                 case STATEMENT_ASM:
4970                         next = stmt->base.next;
4971                         break;
4972
4973                 case STATEMENT_DECLARATION: {
4974                         declaration_statement_t const *const decl = &stmt->declaration;
4975                         entity_t                const *      ent  = decl->declarations_begin;
4976                         entity_t                const *const last_decl = decl->declarations_end;
4977                         if (ent != NULL) {
4978                                 for (;; ent = ent->base.next) {
4979                                         if (ent->kind                 == ENTITY_VARIABLE &&
4980                                             ent->variable.initializer != NULL            &&
4981                                             !initializer_returns(ent->variable.initializer)) {
4982                                                 return;
4983                                         }
4984                                         if (ent == last_decl)
4985                                                 break;
4986                                 }
4987                         }
4988                         next = stmt->base.next;
4989                         break;
4990                 }
4991
4992                 case STATEMENT_COMPOUND:
4993                         next = stmt->compound.statements;
4994                         if (next == NULL)
4995                                 next = stmt->base.next;
4996                         break;
4997
4998                 case STATEMENT_RETURN: {
4999                         expression_t const *const val = stmt->returns.value;
5000                         if (val == NULL || expression_returns(val))
5001                                 noreturn_candidate = false;
5002                         return;
5003                 }
5004
5005                 case STATEMENT_IF: {
5006                         if_statement_t const *const ifs  = &stmt->ifs;
5007                         expression_t   const *const cond = ifs->condition;
5008
5009                         if (!expression_returns(cond))
5010                                 return;
5011
5012                         int const val = determine_truth(cond);
5013
5014                         if (val >= 0)
5015                                 check_reachable(ifs->true_statement);
5016
5017                         if (val > 0)
5018                                 return;
5019
5020                         if (ifs->false_statement != NULL) {
5021                                 check_reachable(ifs->false_statement);
5022                                 return;
5023                         }
5024
5025                         next = stmt->base.next;
5026                         break;
5027                 }
5028
5029                 case STATEMENT_SWITCH: {
5030                         switch_statement_t const *const switchs = &stmt->switchs;
5031                         expression_t       const *const expr    = switchs->expression;
5032
5033                         if (!expression_returns(expr))
5034                                 return;
5035
5036                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
5037                                 long                    const val      = fold_constant_to_int(expr);
5038                                 case_label_statement_t *      defaults = NULL;
5039                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5040                                         if (i->expression == NULL) {
5041                                                 defaults = i;
5042                                                 continue;
5043                                         }
5044
5045                                         if (i->first_case <= val && val <= i->last_case) {
5046                                                 check_reachable((statement_t*)i);
5047                                                 return;
5048                                         }
5049                                 }
5050
5051                                 if (defaults != NULL) {
5052                                         check_reachable((statement_t*)defaults);
5053                                         return;
5054                                 }
5055                         } else {
5056                                 bool has_default = false;
5057                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5058                                         if (i->expression == NULL)
5059                                                 has_default = true;
5060
5061                                         check_reachable((statement_t*)i);
5062                                 }
5063
5064                                 if (has_default)
5065                                         return;
5066                         }
5067
5068                         next = stmt->base.next;
5069                         break;
5070                 }
5071
5072                 case STATEMENT_EXPRESSION: {
5073                         /* Check for noreturn function call */
5074                         expression_t const *const expr = stmt->expression.expression;
5075                         if (!expression_returns(expr))
5076                                 return;
5077
5078                         next = stmt->base.next;
5079                         break;
5080                 }
5081
5082                 case STATEMENT_CONTINUE:
5083                         for (statement_t *parent = stmt;;) {
5084                                 parent = parent->base.parent;
5085                                 if (parent == NULL) /* continue not within loop */
5086                                         return;
5087
5088                                 next = parent;
5089                                 switch (parent->kind) {
5090                                         case STATEMENT_WHILE:    goto continue_while;
5091                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5092                                         case STATEMENT_FOR:      goto continue_for;
5093
5094                                         default: break;
5095                                 }
5096                         }
5097
5098                 case STATEMENT_BREAK:
5099                         for (statement_t *parent = stmt;;) {
5100                                 parent = parent->base.parent;
5101                                 if (parent == NULL) /* break not within loop/switch */
5102                                         return;
5103
5104                                 switch (parent->kind) {
5105                                         case STATEMENT_SWITCH:
5106                                         case STATEMENT_WHILE:
5107                                         case STATEMENT_DO_WHILE:
5108                                         case STATEMENT_FOR:
5109                                                 last = parent;
5110                                                 next = parent->base.next;
5111                                                 goto found_break_parent;
5112
5113                                         default: break;
5114                                 }
5115                         }
5116 found_break_parent:
5117                         break;
5118
5119                 case STATEMENT_GOTO:
5120                         if (stmt->gotos.expression) {
5121                                 if (!expression_returns(stmt->gotos.expression))
5122                                         return;
5123
5124                                 statement_t *parent = stmt->base.parent;
5125                                 if (parent == NULL) /* top level goto */
5126                                         return;
5127                                 next = parent;
5128                         } else {
5129                                 next = stmt->gotos.label->statement;
5130                                 if (next == NULL) /* missing label */
5131                                         return;
5132                         }
5133                         break;
5134
5135                 case STATEMENT_LABEL:
5136                         next = stmt->label.statement;
5137                         break;
5138
5139                 case STATEMENT_CASE_LABEL:
5140                         next = stmt->case_label.statement;
5141                         break;
5142
5143                 case STATEMENT_WHILE: {
5144                         while_statement_t const *const whiles = &stmt->whiles;
5145                         expression_t      const *const cond   = whiles->condition;
5146
5147                         if (!expression_returns(cond))
5148                                 return;
5149
5150                         int const val = determine_truth(cond);
5151
5152                         if (val >= 0)
5153                                 check_reachable(whiles->body);
5154
5155                         if (val > 0)
5156                                 return;
5157
5158                         next = stmt->base.next;
5159                         break;
5160                 }
5161
5162                 case STATEMENT_DO_WHILE:
5163                         next = stmt->do_while.body;
5164                         break;
5165
5166                 case STATEMENT_FOR: {
5167                         for_statement_t *const fors = &stmt->fors;
5168
5169                         if (fors->condition_reachable)
5170                                 return;
5171                         fors->condition_reachable = true;
5172
5173                         expression_t const *const cond = fors->condition;
5174
5175                         int val;
5176                         if (cond == NULL) {
5177                                 val = 1;
5178                         } else if (expression_returns(cond)) {
5179                                 val = determine_truth(cond);
5180                         } else {
5181                                 return;
5182                         }
5183
5184                         if (val >= 0)
5185                                 check_reachable(fors->body);
5186
5187                         if (val > 0)
5188                                 return;
5189
5190                         next = stmt->base.next;
5191                         break;
5192                 }
5193
5194                 case STATEMENT_MS_TRY: {
5195                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5196                         check_reachable(ms_try->try_statement);
5197                         next = ms_try->final_statement;
5198                         break;
5199                 }
5200
5201                 case STATEMENT_LEAVE: {
5202                         statement_t *parent = stmt;
5203                         for (;;) {
5204                                 parent = parent->base.parent;
5205                                 if (parent == NULL) /* __leave not within __try */
5206                                         return;
5207
5208                                 if (parent->kind == STATEMENT_MS_TRY) {
5209                                         last = parent;
5210                                         next = parent->ms_try.final_statement;
5211                                         break;
5212                                 }
5213                         }
5214                         break;
5215                 }
5216
5217                 default:
5218                         panic("invalid statement kind");
5219         }
5220
5221         while (next == NULL) {
5222                 next = last->base.parent;
5223                 if (next == NULL) {
5224                         noreturn_candidate = false;
5225
5226                         type_t *const type = skip_typeref(current_function->base.type);
5227                         assert(is_type_function(type));
5228                         type_t *const ret  = skip_typeref(type->function.return_type);
5229                         if (warning.return_type                    &&
5230                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5231                             is_type_valid(ret)                     &&
5232                             !is_sym_main(current_function->base.base.symbol)) {
5233                                 warningf(&stmt->base.source_position,
5234                                          "control reaches end of non-void function");
5235                         }
5236                         return;
5237                 }
5238
5239                 switch (next->kind) {
5240                         case STATEMENT_INVALID:
5241                         case STATEMENT_EMPTY:
5242                         case STATEMENT_DECLARATION:
5243                         case STATEMENT_EXPRESSION:
5244                         case STATEMENT_ASM:
5245                         case STATEMENT_RETURN:
5246                         case STATEMENT_CONTINUE:
5247                         case STATEMENT_BREAK:
5248                         case STATEMENT_GOTO:
5249                         case STATEMENT_LEAVE:
5250                                 panic("invalid control flow in function");
5251
5252                         case STATEMENT_COMPOUND:
5253                                 if (next->compound.stmt_expr) {
5254                                         reaches_end = true;
5255                                         return;
5256                                 }
5257                                 /* FALLTHROUGH */
5258                         case STATEMENT_IF:
5259                         case STATEMENT_SWITCH:
5260                         case STATEMENT_LABEL:
5261                         case STATEMENT_CASE_LABEL:
5262                                 last = next;
5263                                 next = next->base.next;
5264                                 break;
5265
5266                         case STATEMENT_WHILE: {
5267 continue_while:
5268                                 if (next->base.reachable)
5269                                         return;
5270                                 next->base.reachable = true;
5271
5272                                 while_statement_t const *const whiles = &next->whiles;
5273                                 expression_t      const *const cond   = whiles->condition;
5274
5275                                 if (!expression_returns(cond))
5276                                         return;
5277
5278                                 int const val = determine_truth(cond);
5279
5280                                 if (val >= 0)
5281                                         check_reachable(whiles->body);
5282
5283                                 if (val > 0)
5284                                         return;
5285
5286                                 last = next;
5287                                 next = next->base.next;
5288                                 break;
5289                         }
5290
5291                         case STATEMENT_DO_WHILE: {
5292 continue_do_while:
5293                                 if (next->base.reachable)
5294                                         return;
5295                                 next->base.reachable = true;
5296
5297                                 do_while_statement_t const *const dw   = &next->do_while;
5298                                 expression_t         const *const cond = dw->condition;
5299
5300                                 if (!expression_returns(cond))
5301                                         return;
5302
5303                                 int const val = determine_truth(cond);
5304
5305                                 if (val >= 0)
5306                                         check_reachable(dw->body);
5307
5308                                 if (val > 0)
5309                                         return;
5310
5311                                 last = next;
5312                                 next = next->base.next;
5313                                 break;
5314                         }
5315
5316                         case STATEMENT_FOR: {
5317 continue_for:;
5318                                 for_statement_t *const fors = &next->fors;
5319
5320                                 fors->step_reachable = true;
5321
5322                                 if (fors->condition_reachable)
5323                                         return;
5324                                 fors->condition_reachable = true;
5325
5326                                 expression_t const *const cond = fors->condition;
5327
5328                                 int val;
5329                                 if (cond == NULL) {
5330                                         val = 1;
5331                                 } else if (expression_returns(cond)) {
5332                                         val = determine_truth(cond);
5333                                 } else {
5334                                         return;
5335                                 }
5336
5337                                 if (val >= 0)
5338                                         check_reachable(fors->body);
5339
5340                                 if (val > 0)
5341                                         return;
5342
5343                                 last = next;
5344                                 next = next->base.next;
5345                                 break;
5346                         }
5347
5348                         case STATEMENT_MS_TRY:
5349                                 last = next;
5350                                 next = next->ms_try.final_statement;
5351                                 break;
5352                 }
5353         }
5354
5355         check_reachable(next);
5356 }
5357
5358 static void check_unreachable(statement_t* const stmt, void *const env)
5359 {
5360         (void)env;
5361
5362         switch (stmt->kind) {
5363                 case STATEMENT_DO_WHILE:
5364                         if (!stmt->base.reachable) {
5365                                 expression_t const *const cond = stmt->do_while.condition;
5366                                 if (determine_truth(cond) >= 0) {
5367                                         warningf(&cond->base.source_position,
5368                                                  "condition of do-while-loop is unreachable");
5369                                 }
5370                         }
5371                         return;
5372
5373                 case STATEMENT_FOR: {
5374                         for_statement_t const* const fors = &stmt->fors;
5375
5376                         // if init and step are unreachable, cond is unreachable, too
5377                         if (!stmt->base.reachable && !fors->step_reachable) {
5378                                 warningf(&stmt->base.source_position, "statement is unreachable");
5379                         } else {
5380                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5381                                         warningf(&fors->initialisation->base.source_position,
5382                                                  "initialisation of for-statement is unreachable");
5383                                 }
5384
5385                                 if (!fors->condition_reachable && fors->condition != NULL) {
5386                                         warningf(&fors->condition->base.source_position,
5387                                                  "condition of for-statement is unreachable");
5388                                 }
5389
5390                                 if (!fors->step_reachable && fors->step != NULL) {
5391                                         warningf(&fors->step->base.source_position,
5392                                                  "step of for-statement is unreachable");
5393                                 }
5394                         }
5395                         return;
5396                 }
5397
5398                 case STATEMENT_COMPOUND:
5399                         if (stmt->compound.statements != NULL)
5400                                 return;
5401                         goto warn_unreachable;
5402
5403                 case STATEMENT_DECLARATION: {
5404                         /* Only warn if there is at least one declarator with an initializer.
5405                          * This typically occurs in switch statements. */
5406                         declaration_statement_t const *const decl = &stmt->declaration;
5407                         entity_t                const *      ent  = decl->declarations_begin;
5408                         entity_t                const *const last = decl->declarations_end;
5409                         if (ent != NULL) {
5410                                 for (;; ent = ent->base.next) {
5411                                         if (ent->kind                 == ENTITY_VARIABLE &&
5412                                                         ent->variable.initializer != NULL) {
5413                                                 goto warn_unreachable;
5414                                         }
5415                                         if (ent == last)
5416                                                 return;
5417                                 }
5418                         }
5419                 }
5420
5421                 default:
5422 warn_unreachable:
5423                         if (!stmt->base.reachable)
5424                                 warningf(&stmt->base.source_position, "statement is unreachable");
5425                         return;
5426         }
5427 }
5428
5429 static void parse_external_declaration(void)
5430 {
5431         /* function-definitions and declarations both start with declaration
5432          * specifiers */
5433         add_anchor_token(';');
5434         declaration_specifiers_t specifiers;
5435         parse_declaration_specifiers(&specifiers);
5436         rem_anchor_token(';');
5437
5438         /* must be a declaration */
5439         if (token.type == ';') {
5440                 parse_anonymous_declaration_rest(&specifiers);
5441                 return;
5442         }
5443
5444         add_anchor_token(',');
5445         add_anchor_token('=');
5446         add_anchor_token(';');
5447         add_anchor_token('{');
5448
5449         /* declarator is common to both function-definitions and declarations */
5450         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5451
5452         rem_anchor_token('{');
5453         rem_anchor_token(';');
5454         rem_anchor_token('=');
5455         rem_anchor_token(',');
5456
5457         /* must be a declaration */
5458         switch (token.type) {
5459                 case ',':
5460                 case ';':
5461                 case '=':
5462                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5463                                         DECL_FLAGS_NONE);
5464                         return;
5465         }
5466
5467         /* must be a function definition */
5468         parse_kr_declaration_list(ndeclaration);
5469
5470         if (token.type != '{') {
5471                 parse_error_expected("while parsing function definition", '{', NULL);
5472                 eat_until_matching_token(';');
5473                 return;
5474         }
5475
5476         assert(is_declaration(ndeclaration));
5477         type_t *const orig_type = ndeclaration->declaration.type;
5478         type_t *      type      = skip_typeref(orig_type);
5479
5480         if (!is_type_function(type)) {
5481                 if (is_type_valid(type)) {
5482                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5483                 }
5484                 eat_block();
5485                 return;
5486         }
5487
5488         source_position_t const *const pos = &ndeclaration->base.source_position;
5489         if (is_typeref(orig_type)) {
5490                 /* §6.9.1:2 */
5491                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5492         }
5493
5494         if (warning.aggregate_return &&
5495             is_type_compound(skip_typeref(type->function.return_type))) {
5496                 warningf(pos, "'%N' returns an aggregate", ndeclaration);
5497         }
5498         if (warning.traditional && !type->function.unspecified_parameters) {
5499                 warningf(pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5500         }
5501         if (warning.old_style_definition && type->function.unspecified_parameters) {
5502                 warningf(pos, "old-style definition of '%N'", ndeclaration);
5503         }
5504
5505         /* §6.7.5.3:14 a function definition with () means no
5506          * parameters (and not unspecified parameters) */
5507         if (type->function.unspecified_parameters &&
5508                         type->function.parameters == NULL) {
5509                 type_t *copy                          = duplicate_type(type);
5510                 copy->function.unspecified_parameters = false;
5511                 type                                  = identify_new_type(copy);
5512
5513                 ndeclaration->declaration.type = type;
5514         }
5515
5516         entity_t *const entity = record_entity(ndeclaration, true);
5517         assert(entity->kind == ENTITY_FUNCTION);
5518         assert(ndeclaration->kind == ENTITY_FUNCTION);
5519
5520         function_t *const function = &entity->function;
5521         if (ndeclaration != entity) {
5522                 function->parameters = ndeclaration->function.parameters;
5523         }
5524         assert(is_declaration(entity));
5525         type = skip_typeref(entity->declaration.type);
5526
5527         /* push function parameters and switch scope */
5528         size_t const  top       = environment_top();
5529         scope_t      *old_scope = scope_push(&function->parameters);
5530
5531         entity_t *parameter = function->parameters.entities;
5532         for (; parameter != NULL; parameter = parameter->base.next) {
5533                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5534                         parameter->base.parent_scope = current_scope;
5535                 }
5536                 assert(parameter->base.parent_scope == NULL
5537                                 || parameter->base.parent_scope == current_scope);
5538                 parameter->base.parent_scope = current_scope;
5539                 if (parameter->base.symbol == NULL) {
5540                         errorf(&parameter->base.source_position, "parameter name omitted");
5541                         continue;
5542                 }
5543                 environment_push(parameter);
5544         }
5545
5546         if (function->statement != NULL) {
5547                 parser_error_multiple_definition(entity, HERE);
5548                 eat_block();
5549         } else {
5550                 /* parse function body */
5551                 int         label_stack_top      = label_top();
5552                 function_t *old_current_function = current_function;
5553                 entity_t   *old_current_entity   = current_entity;
5554                 current_function                 = function;
5555                 current_entity                   = entity;
5556                 current_parent                   = NULL;
5557
5558                 goto_first   = NULL;
5559                 goto_anchor  = &goto_first;
5560                 label_first  = NULL;
5561                 label_anchor = &label_first;
5562
5563                 statement_t *const body = parse_compound_statement(false);
5564                 function->statement = body;
5565                 first_err = true;
5566                 check_labels();
5567                 check_declarations();
5568                 if (warning.return_type      ||
5569                     warning.unreachable_code ||
5570                     (warning.missing_noreturn
5571                      && !(function->base.modifiers & DM_NORETURN))) {
5572                         noreturn_candidate = true;
5573                         check_reachable(body);
5574                         if (warning.unreachable_code)
5575                                 walk_statements(body, check_unreachable, NULL);
5576                         if (warning.missing_noreturn &&
5577                             noreturn_candidate       &&
5578                             !(function->base.modifiers & DM_NORETURN)) {
5579                                 source_position_t const *const pos = &body->base.source_position;
5580                                 warningf(pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5581                         }
5582                 }
5583
5584                 assert(current_parent   == NULL);
5585                 assert(current_function == function);
5586                 assert(current_entity   == entity);
5587                 current_entity   = old_current_entity;
5588                 current_function = old_current_function;
5589                 label_pop_to(label_stack_top);
5590         }
5591
5592         assert(current_scope == &function->parameters);
5593         scope_pop(old_scope);
5594         environment_pop_to(top);
5595 }
5596
5597 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5598                                   source_position_t *source_position,
5599                                   const symbol_t *symbol)
5600 {
5601         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5602
5603         type->bitfield.base_type       = base_type;
5604         type->bitfield.size_expression = size;
5605
5606         il_size_t bit_size;
5607         type_t *skipped_type = skip_typeref(base_type);
5608         if (!is_type_integer(skipped_type)) {
5609                 errorf(source_position, "bitfield base type '%T' is not an integer type", base_type);
5610                 bit_size = 0;
5611         } else {
5612                 bit_size = get_type_size(base_type) * 8;
5613         }
5614
5615         if (is_constant_expression(size) == EXPR_CLASS_CONSTANT) {
5616                 long v = fold_constant_to_int(size);
5617                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5618
5619                 if (v < 0) {
5620                         errorf(source_position, "negative width in bit-field '%Y'",
5621                                user_symbol);
5622                 } else if (v == 0 && symbol != NULL) {
5623                         errorf(source_position, "zero width for bit-field '%Y'",
5624                                user_symbol);
5625                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5626                         errorf(source_position, "width of '%Y' exceeds its type",
5627                                user_symbol);
5628                 } else {
5629                         type->bitfield.bit_size = v;
5630                 }
5631         }
5632
5633         return type;
5634 }
5635
5636 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5637 {
5638         entity_t *iter = compound->members.entities;
5639         for (; iter != NULL; iter = iter->base.next) {
5640                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5641                         continue;
5642
5643                 if (iter->base.symbol == symbol) {
5644                         return iter;
5645                 } else if (iter->base.symbol == NULL) {
5646                         /* search in anonymous structs and unions */
5647                         type_t *type = skip_typeref(iter->declaration.type);
5648                         if (is_type_compound(type)) {
5649                                 if (find_compound_entry(type->compound.compound, symbol)
5650                                                 != NULL)
5651                                         return iter;
5652                         }
5653                         continue;
5654                 }
5655         }
5656
5657         return NULL;
5658 }
5659
5660 static void check_deprecated(const source_position_t *source_position,
5661                              const entity_t *entity)
5662 {
5663         if (!warning.deprecated_declarations)
5664                 return;
5665         if (!is_declaration(entity))
5666                 return;
5667         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5668                 return;
5669
5670         source_position_t const *const pos = &entity->base.source_position;
5671         char              const* const msg = get_deprecated_string(entity->declaration.attributes);
5672         if (msg != NULL) {
5673                 warningf(source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, pos, msg);
5674         } else {
5675                 warningf(source_position, "'%N' is deprecated (declared %P)", entity, pos);
5676         }
5677 }
5678
5679
5680 static expression_t *create_select(const source_position_t *pos,
5681                                    expression_t *addr,
5682                                    type_qualifiers_t qualifiers,
5683                                                                    entity_t *entry)
5684 {
5685         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5686
5687         check_deprecated(pos, entry);
5688
5689         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5690         select->select.compound       = addr;
5691         select->select.compound_entry = entry;
5692
5693         type_t *entry_type = entry->declaration.type;
5694         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5695
5696         /* we always do the auto-type conversions; the & and sizeof parser contains
5697          * code to revert this! */
5698         select->base.type = automatic_type_conversion(res_type);
5699         if (res_type->kind == TYPE_BITFIELD) {
5700                 select->base.type = res_type->bitfield.base_type;
5701         }
5702
5703         return select;
5704 }
5705
5706 /**
5707  * Find entry with symbol in compound. Search anonymous structs and unions and
5708  * creates implicit select expressions for them.
5709  * Returns the adress for the innermost compound.
5710  */
5711 static expression_t *find_create_select(const source_position_t *pos,
5712                                         expression_t *addr,
5713                                         type_qualifiers_t qualifiers,
5714                                         compound_t *compound, symbol_t *symbol)
5715 {
5716         entity_t *iter = compound->members.entities;
5717         for (; iter != NULL; iter = iter->base.next) {
5718                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5719                         continue;
5720
5721                 symbol_t *iter_symbol = iter->base.symbol;
5722                 if (iter_symbol == NULL) {
5723                         type_t *type = iter->declaration.type;
5724                         if (type->kind != TYPE_COMPOUND_STRUCT
5725                                         && type->kind != TYPE_COMPOUND_UNION)
5726                                 continue;
5727
5728                         compound_t *sub_compound = type->compound.compound;
5729
5730                         if (find_compound_entry(sub_compound, symbol) == NULL)
5731                                 continue;
5732
5733                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5734                         sub_addr->base.source_position = *pos;
5735                         sub_addr->select.implicit      = true;
5736                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5737                                                   symbol);
5738                 }
5739
5740                 if (iter_symbol == symbol) {
5741                         return create_select(pos, addr, qualifiers, iter);
5742                 }
5743         }
5744
5745         return NULL;
5746 }
5747
5748 static void parse_compound_declarators(compound_t *compound,
5749                 const declaration_specifiers_t *specifiers)
5750 {
5751         do {
5752                 entity_t *entity;
5753
5754                 if (token.type == ':') {
5755                         source_position_t source_position = *HERE;
5756                         next_token();
5757
5758                         type_t *base_type = specifiers->type;
5759                         expression_t *size = parse_constant_expression();
5760
5761                         type_t *type = make_bitfield_type(base_type, size,
5762                                         &source_position, NULL);
5763
5764                         attribute_t  *attributes = parse_attributes(NULL);
5765                         attribute_t **anchor     = &attributes;
5766                         while (*anchor != NULL)
5767                                 anchor = &(*anchor)->next;
5768                         *anchor = specifiers->attributes;
5769
5770                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL);
5771                         entity->base.source_position               = source_position;
5772                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5773                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5774                         entity->declaration.type                   = type;
5775                         entity->declaration.attributes             = attributes;
5776
5777                         if (attributes != NULL) {
5778                                 handle_entity_attributes(attributes, entity);
5779                         }
5780                         append_entity(&compound->members, entity);
5781                 } else {
5782                         entity = parse_declarator(specifiers,
5783                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5784                         source_position_t const *const pos = &entity->base.source_position;
5785                         if (entity->kind == ENTITY_TYPEDEF) {
5786                                 errorf(pos, "typedef not allowed as compound member");
5787                         } else {
5788                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5789
5790                                 /* make sure we don't define a symbol multiple times */
5791                                 symbol_t *symbol = entity->base.symbol;
5792                                 if (symbol != NULL) {
5793                                         entity_t *prev = find_compound_entry(compound, symbol);
5794                                         if (prev != NULL) {
5795                                                 source_position_t const *const ppos = &prev->base.source_position;
5796                                                 errorf(pos, "multiple declarations of symbol '%Y' (declared %P)", symbol, ppos);
5797                                         }
5798                                 }
5799
5800                                 if (token.type == ':') {
5801                                         source_position_t source_position = *HERE;
5802                                         next_token();
5803                                         expression_t *size = parse_constant_expression();
5804
5805                                         type_t *type          = entity->declaration.type;
5806                                         type_t *bitfield_type = make_bitfield_type(type, size,
5807                                                         &source_position, entity->base.symbol);
5808
5809                                         attribute_t *attributes = parse_attributes(NULL);
5810                                         entity->declaration.type = bitfield_type;
5811                                         handle_entity_attributes(attributes, entity);
5812                                 } else {
5813                                         type_t *orig_type = entity->declaration.type;
5814                                         type_t *type      = skip_typeref(orig_type);
5815                                         if (is_type_function(type)) {
5816                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5817                                         } else if (is_type_incomplete(type)) {
5818                                                 /* §6.7.2.1:16 flexible array member */
5819                                                 if (!is_type_array(type)       ||
5820                                                                 token.type          != ';' ||
5821                                                                 look_ahead(1)->type != '}') {
5822                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5823                                                 }
5824                                         }
5825                                 }
5826
5827                                 append_entity(&compound->members, entity);
5828                         }
5829                 }
5830         } while (next_if(','));
5831         expect(';', end_error);
5832
5833 end_error:
5834         anonymous_entity = NULL;
5835 }
5836
5837 static void parse_compound_type_entries(compound_t *compound)
5838 {
5839         eat('{');
5840         add_anchor_token('}');
5841
5842         while (token.type != '}') {
5843                 if (token.type == T_EOF) {
5844                         errorf(HERE, "EOF while parsing struct");
5845                         break;
5846                 }
5847                 declaration_specifiers_t specifiers;
5848                 parse_declaration_specifiers(&specifiers);
5849                 parse_compound_declarators(compound, &specifiers);
5850         }
5851         rem_anchor_token('}');
5852         next_token();
5853
5854         /* §6.7.2.1:7 */
5855         compound->complete = true;
5856 }
5857
5858 static type_t *parse_typename(void)
5859 {
5860         declaration_specifiers_t specifiers;
5861         parse_declaration_specifiers(&specifiers);
5862         if (specifiers.storage_class != STORAGE_CLASS_NONE
5863                         || specifiers.thread_local) {
5864                 /* TODO: improve error message, user does probably not know what a
5865                  * storage class is...
5866                  */
5867                 errorf(&specifiers.source_position, "typename must not have a storage class");
5868         }
5869
5870         type_t *result = parse_abstract_declarator(specifiers.type);
5871
5872         return result;
5873 }
5874
5875
5876
5877
5878 typedef expression_t* (*parse_expression_function)(void);
5879 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5880
5881 typedef struct expression_parser_function_t expression_parser_function_t;
5882 struct expression_parser_function_t {
5883         parse_expression_function        parser;
5884         precedence_t                     infix_precedence;
5885         parse_expression_infix_function  infix_parser;
5886 };
5887
5888 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5889
5890 /**
5891  * Prints an error message if an expression was expected but not read
5892  */
5893 static expression_t *expected_expression_error(void)
5894 {
5895         /* skip the error message if the error token was read */
5896         if (token.type != T_ERROR) {
5897                 errorf(HERE, "expected expression, got token %K", &token);
5898         }
5899         next_token();
5900
5901         return create_invalid_expression();
5902 }
5903
5904 static type_t *get_string_type(void)
5905 {
5906         return warning.write_strings ? type_const_char_ptr : type_char_ptr;
5907 }
5908
5909 static type_t *get_wide_string_type(void)
5910 {
5911         return warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5912 }
5913
5914 /**
5915  * Parse a string constant.
5916  */
5917 static expression_t *parse_string_literal(void)
5918 {
5919         source_position_t begin   = token.source_position;
5920         string_t          res     = token.literal;
5921         bool              is_wide = (token.type == T_WIDE_STRING_LITERAL);
5922
5923         next_token();
5924         while (token.type == T_STRING_LITERAL
5925                         || token.type == T_WIDE_STRING_LITERAL) {
5926                 warn_string_concat(&token.source_position);
5927                 res = concat_strings(&res, &token.literal);
5928                 next_token();
5929                 is_wide |= token.type == T_WIDE_STRING_LITERAL;
5930         }
5931
5932         expression_t *literal;
5933         if (is_wide) {
5934                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5935                 literal->base.type = get_wide_string_type();
5936         } else {
5937                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5938                 literal->base.type = get_string_type();
5939         }
5940         literal->base.source_position = begin;
5941         literal->literal.value        = res;
5942
5943         return literal;
5944 }
5945
5946 /**
5947  * Parse a boolean constant.
5948  */
5949 static expression_t *parse_boolean_literal(bool value)
5950 {
5951         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5952         literal->base.source_position = token.source_position;
5953         literal->base.type            = type_bool;
5954         literal->literal.value.begin  = value ? "true" : "false";
5955         literal->literal.value.size   = value ? 4 : 5;
5956
5957         next_token();
5958         return literal;
5959 }
5960
5961 static void warn_traditional_suffix(void)
5962 {
5963         if (!warning.traditional)
5964                 return;
5965         warningf(&token.source_position, "traditional C rejects the '%Y' suffix",
5966                  token.symbol);
5967 }
5968
5969 static void check_integer_suffix(void)
5970 {
5971         symbol_t *suffix = token.symbol;
5972         if (suffix == NULL)
5973                 return;
5974
5975         bool not_traditional = false;
5976         const char *c = suffix->string;
5977         if (*c == 'l' || *c == 'L') {
5978                 ++c;
5979                 if (*c == *(c-1)) {
5980                         not_traditional = true;
5981                         ++c;
5982                         if (*c == 'u' || *c == 'U') {
5983                                 ++c;
5984                         }
5985                 } else if (*c == 'u' || *c == 'U') {
5986                         not_traditional = true;
5987                         ++c;
5988                 }
5989         } else if (*c == 'u' || *c == 'U') {
5990                 not_traditional = true;
5991                 ++c;
5992                 if (*c == 'l' || *c == 'L') {
5993                         ++c;
5994                         if (*c == *(c-1)) {
5995                                 ++c;
5996                         }
5997                 }
5998         }
5999         if (*c != '\0') {
6000                 errorf(&token.source_position,
6001                        "invalid suffix '%s' on integer constant", suffix->string);
6002         } else if (not_traditional) {
6003                 warn_traditional_suffix();
6004         }
6005 }
6006
6007 static type_t *check_floatingpoint_suffix(void)
6008 {
6009         symbol_t *suffix = token.symbol;
6010         type_t   *type   = type_double;
6011         if (suffix == NULL)
6012                 return type;
6013
6014         bool not_traditional = false;
6015         const char *c = suffix->string;
6016         if (*c == 'f' || *c == 'F') {
6017                 ++c;
6018                 type = type_float;
6019         } else if (*c == 'l' || *c == 'L') {
6020                 ++c;
6021                 type = type_long_double;
6022         }
6023         if (*c != '\0') {
6024                 errorf(&token.source_position,
6025                        "invalid suffix '%s' on floatingpoint constant", suffix->string);
6026         } else if (not_traditional) {
6027                 warn_traditional_suffix();
6028         }
6029
6030         return type;
6031 }
6032
6033 /**
6034  * Parse an integer constant.
6035  */
6036 static expression_t *parse_number_literal(void)
6037 {
6038         expression_kind_t  kind;
6039         type_t            *type;
6040
6041         switch (token.type) {
6042         case T_INTEGER:
6043                 kind = EXPR_LITERAL_INTEGER;
6044                 check_integer_suffix();
6045                 type = type_int;
6046                 break;
6047         case T_INTEGER_OCTAL:
6048                 kind = EXPR_LITERAL_INTEGER_OCTAL;
6049                 check_integer_suffix();
6050                 type = type_int;
6051                 break;
6052         case T_INTEGER_HEXADECIMAL:
6053                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
6054                 check_integer_suffix();
6055                 type = type_int;
6056                 break;
6057         case T_FLOATINGPOINT:
6058                 kind = EXPR_LITERAL_FLOATINGPOINT;
6059                 type = check_floatingpoint_suffix();
6060                 break;
6061         case T_FLOATINGPOINT_HEXADECIMAL:
6062                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
6063                 type = check_floatingpoint_suffix();
6064                 break;
6065         default:
6066                 panic("unexpected token type in parse_number_literal");
6067         }
6068
6069         expression_t *literal = allocate_expression_zero(kind);
6070         literal->base.source_position = token.source_position;
6071         literal->base.type            = type;
6072         literal->literal.value        = token.literal;
6073         literal->literal.suffix       = token.symbol;
6074         next_token();
6075
6076         /* integer type depends on the size of the number and the size
6077          * representable by the types. The backend/codegeneration has to determine
6078          * that
6079          */
6080         determine_literal_type(&literal->literal);
6081         return literal;
6082 }
6083
6084 /**
6085  * Parse a character constant.
6086  */
6087 static expression_t *parse_character_constant(void)
6088 {
6089         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
6090         literal->base.source_position = token.source_position;
6091         literal->base.type            = c_mode & _CXX ? type_char : type_int;
6092         literal->literal.value        = token.literal;
6093
6094         size_t len = literal->literal.value.size;
6095         if (len > 1) {
6096                 if (!GNU_MODE && !(c_mode & _C99)) {
6097                         errorf(HERE, "more than 1 character in character constant");
6098                 } else if (warning.multichar) {
6099                         literal->base.type = type_int;
6100                         warningf(HERE, "multi-character character constant");
6101                 }
6102         }
6103
6104         next_token();
6105         return literal;
6106 }
6107
6108 /**
6109  * Parse a wide character constant.
6110  */
6111 static expression_t *parse_wide_character_constant(void)
6112 {
6113         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6114         literal->base.source_position = token.source_position;
6115         literal->base.type            = type_int;
6116         literal->literal.value        = token.literal;
6117
6118         size_t len = wstrlen(&literal->literal.value);
6119         if (len > 1) {
6120                 warningf(HERE, "multi-character character constant");
6121         }
6122
6123         next_token();
6124         return literal;
6125 }
6126
6127 static entity_t *create_implicit_function(symbol_t *symbol,
6128                 const source_position_t *source_position)
6129 {
6130         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6131         ntype->function.return_type            = type_int;
6132         ntype->function.unspecified_parameters = true;
6133         ntype->function.linkage                = LINKAGE_C;
6134         type_t *type                           = identify_new_type(ntype);
6135
6136         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol);
6137         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6138         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6139         entity->declaration.type                   = type;
6140         entity->declaration.implicit               = true;
6141         entity->base.source_position               = *source_position;
6142
6143         if (current_scope != NULL) {
6144                 bool strict_prototypes_old = warning.strict_prototypes;
6145                 warning.strict_prototypes  = false;
6146                 record_entity(entity, false);
6147                 warning.strict_prototypes = strict_prototypes_old;
6148         }
6149
6150         return entity;
6151 }
6152
6153 /**
6154  * Performs automatic type cast as described in §6.3.2.1.
6155  *
6156  * @param orig_type  the original type
6157  */
6158 static type_t *automatic_type_conversion(type_t *orig_type)
6159 {
6160         type_t *type = skip_typeref(orig_type);
6161         if (is_type_array(type)) {
6162                 array_type_t *array_type   = &type->array;
6163                 type_t       *element_type = array_type->element_type;
6164                 unsigned      qualifiers   = array_type->base.qualifiers;
6165
6166                 return make_pointer_type(element_type, qualifiers);
6167         }
6168
6169         if (is_type_function(type)) {
6170                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6171         }
6172
6173         return orig_type;
6174 }
6175
6176 /**
6177  * reverts the automatic casts of array to pointer types and function
6178  * to function-pointer types as defined §6.3.2.1
6179  */
6180 type_t *revert_automatic_type_conversion(const expression_t *expression)
6181 {
6182         switch (expression->kind) {
6183         case EXPR_REFERENCE: {
6184                 entity_t *entity = expression->reference.entity;
6185                 if (is_declaration(entity)) {
6186                         return entity->declaration.type;
6187                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6188                         return entity->enum_value.enum_type;
6189                 } else {
6190                         panic("no declaration or enum in reference");
6191                 }
6192         }
6193
6194         case EXPR_SELECT: {
6195                 entity_t *entity = expression->select.compound_entry;
6196                 assert(is_declaration(entity));
6197                 type_t   *type   = entity->declaration.type;
6198                 return get_qualified_type(type,
6199                                 expression->base.type->base.qualifiers);
6200         }
6201
6202         case EXPR_UNARY_DEREFERENCE: {
6203                 const expression_t *const value = expression->unary.value;
6204                 type_t             *const type  = skip_typeref(value->base.type);
6205                 if (!is_type_pointer(type))
6206                         return type_error_type;
6207                 return type->pointer.points_to;
6208         }
6209
6210         case EXPR_ARRAY_ACCESS: {
6211                 const expression_t *array_ref = expression->array_access.array_ref;
6212                 type_t             *type_left = skip_typeref(array_ref->base.type);
6213                 if (!is_type_pointer(type_left))
6214                         return type_error_type;
6215                 return type_left->pointer.points_to;
6216         }
6217
6218         case EXPR_STRING_LITERAL: {
6219                 size_t size = expression->string_literal.value.size;
6220                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6221         }
6222
6223         case EXPR_WIDE_STRING_LITERAL: {
6224                 size_t size = wstrlen(&expression->string_literal.value);
6225                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6226         }
6227
6228         case EXPR_COMPOUND_LITERAL:
6229                 return expression->compound_literal.type;
6230
6231         default:
6232                 break;
6233         }
6234         return expression->base.type;
6235 }
6236
6237 /**
6238  * Find an entity matching a symbol in a scope.
6239  * Uses current scope if scope is NULL
6240  */
6241 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6242                                namespace_tag_t namespc)
6243 {
6244         if (scope == NULL) {
6245                 return get_entity(symbol, namespc);
6246         }
6247
6248         /* we should optimize here, if scope grows above a certain size we should
6249            construct a hashmap here... */
6250         entity_t *entity = scope->entities;
6251         for ( ; entity != NULL; entity = entity->base.next) {
6252                 if (entity->base.symbol == symbol
6253                     && (namespace_tag_t)entity->base.namespc == namespc)
6254                         break;
6255         }
6256
6257         return entity;
6258 }
6259
6260 static entity_t *parse_qualified_identifier(void)
6261 {
6262         /* namespace containing the symbol */
6263         symbol_t          *symbol;
6264         source_position_t  pos;
6265         const scope_t     *lookup_scope = NULL;
6266
6267         if (next_if(T_COLONCOLON))
6268                 lookup_scope = &unit->scope;
6269
6270         entity_t *entity;
6271         while (true) {
6272                 if (token.type != T_IDENTIFIER) {
6273                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6274                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6275                 }
6276                 symbol = token.symbol;
6277                 pos    = *HERE;
6278                 next_token();
6279
6280                 /* lookup entity */
6281                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6282
6283                 if (!next_if(T_COLONCOLON))
6284                         break;
6285
6286                 switch (entity->kind) {
6287                 case ENTITY_NAMESPACE:
6288                         lookup_scope = &entity->namespacee.members;
6289                         break;
6290                 case ENTITY_STRUCT:
6291                 case ENTITY_UNION:
6292                 case ENTITY_CLASS:
6293                         lookup_scope = &entity->compound.members;
6294                         break;
6295                 default:
6296                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6297                                symbol, get_entity_kind_name(entity->kind));
6298
6299                         /* skip further qualifications */
6300                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6301
6302                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6303                 }
6304         }
6305
6306         if (entity == NULL) {
6307                 if (!strict_mode && token.type == '(') {
6308                         /* an implicitly declared function */
6309                         if (warning.error_implicit_function_declaration) {
6310                                 errorf(&pos, "implicit declaration of function '%Y'", symbol);
6311                         } else if (warning.implicit_function_declaration) {
6312                                 warningf(&pos, "implicit declaration of function '%Y'", symbol);
6313                         }
6314
6315                         entity = create_implicit_function(symbol, &pos);
6316                 } else {
6317                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6318                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6319                 }
6320         }
6321
6322         return entity;
6323 }
6324
6325 static expression_t *parse_reference(void)
6326 {
6327         source_position_t const pos    = token.source_position;
6328         entity_t         *const entity = parse_qualified_identifier();
6329
6330         type_t *orig_type;
6331         if (is_declaration(entity)) {
6332                 orig_type = entity->declaration.type;
6333         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6334                 orig_type = entity->enum_value.enum_type;
6335         } else {
6336                 panic("expected declaration or enum value in reference");
6337         }
6338
6339         /* we always do the auto-type conversions; the & and sizeof parser contains
6340          * code to revert this! */
6341         type_t *type = automatic_type_conversion(orig_type);
6342
6343         expression_kind_t kind = EXPR_REFERENCE;
6344         if (entity->kind == ENTITY_ENUM_VALUE)
6345                 kind = EXPR_REFERENCE_ENUM_VALUE;
6346
6347         expression_t *expression         = allocate_expression_zero(kind);
6348         expression->base.source_position = pos;
6349         expression->base.type            = type;
6350         expression->reference.entity     = entity;
6351
6352         /* this declaration is used */
6353         if (is_declaration(entity)) {
6354                 entity->declaration.used = true;
6355         }
6356
6357         if (entity->base.parent_scope != file_scope
6358                 && (current_function != NULL
6359                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6360                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6361                 if (entity->kind == ENTITY_VARIABLE) {
6362                         /* access of a variable from an outer function */
6363                         entity->variable.address_taken = true;
6364                 } else if (entity->kind == ENTITY_PARAMETER) {
6365                         entity->parameter.address_taken = true;
6366                 }
6367                 current_function->need_closure = true;
6368         }
6369
6370         check_deprecated(&pos, entity);
6371
6372         if (warning.init_self && entity == current_init_decl && !in_type_prop
6373             && entity->kind == ENTITY_VARIABLE) {
6374                 current_init_decl = NULL;
6375                 warningf(&pos, "variable '%#N' is initialized by itself", entity);
6376         }
6377
6378         return expression;
6379 }
6380
6381 static bool semantic_cast(expression_t *cast)
6382 {
6383         expression_t            *expression      = cast->unary.value;
6384         type_t                  *orig_dest_type  = cast->base.type;
6385         type_t                  *orig_type_right = expression->base.type;
6386         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6387         type_t            const *src_type        = skip_typeref(orig_type_right);
6388         source_position_t const *pos             = &cast->base.source_position;
6389
6390         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6391         if (dst_type == type_void)
6392                 return true;
6393
6394         /* only integer and pointer can be casted to pointer */
6395         if (is_type_pointer(dst_type)  &&
6396             !is_type_pointer(src_type) &&
6397             !is_type_integer(src_type) &&
6398             is_type_valid(src_type)) {
6399                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6400                 return false;
6401         }
6402
6403         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6404                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6405                 return false;
6406         }
6407
6408         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6409                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6410                 return false;
6411         }
6412
6413         if (warning.cast_qual &&
6414             is_type_pointer(src_type) &&
6415             is_type_pointer(dst_type)) {
6416                 type_t *src = skip_typeref(src_type->pointer.points_to);
6417                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6418                 unsigned missing_qualifiers =
6419                         src->base.qualifiers & ~dst->base.qualifiers;
6420                 if (missing_qualifiers != 0) {
6421                         warningf(pos,
6422                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6423                                  missing_qualifiers, orig_type_right);
6424                 }
6425         }
6426         return true;
6427 }
6428
6429 static expression_t *parse_compound_literal(type_t *type)
6430 {
6431         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6432
6433         parse_initializer_env_t env;
6434         env.type             = type;
6435         env.entity           = NULL;
6436         env.must_be_constant = false;
6437         initializer_t *initializer = parse_initializer(&env);
6438         type = env.type;
6439
6440         expression->compound_literal.initializer = initializer;
6441         expression->compound_literal.type        = type;
6442         expression->base.type                    = automatic_type_conversion(type);
6443
6444         return expression;
6445 }
6446
6447 /**
6448  * Parse a cast expression.
6449  */
6450 static expression_t *parse_cast(void)
6451 {
6452         source_position_t source_position = token.source_position;
6453
6454         eat('(');
6455         add_anchor_token(')');
6456
6457         type_t *type = parse_typename();
6458
6459         rem_anchor_token(')');
6460         expect(')', end_error);
6461
6462         if (token.type == '{') {
6463                 return parse_compound_literal(type);
6464         }
6465
6466         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6467         cast->base.source_position = source_position;
6468
6469         expression_t *value = parse_subexpression(PREC_CAST);
6470         cast->base.type   = type;
6471         cast->unary.value = value;
6472
6473         if (! semantic_cast(cast)) {
6474                 /* TODO: record the error in the AST. else it is impossible to detect it */
6475         }
6476
6477         return cast;
6478 end_error:
6479         return create_invalid_expression();
6480 }
6481
6482 /**
6483  * Parse a statement expression.
6484  */
6485 static expression_t *parse_statement_expression(void)
6486 {
6487         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6488
6489         eat('(');
6490         add_anchor_token(')');
6491
6492         statement_t *statement          = parse_compound_statement(true);
6493         statement->compound.stmt_expr   = true;
6494         expression->statement.statement = statement;
6495
6496         /* find last statement and use its type */
6497         type_t *type = type_void;
6498         const statement_t *stmt = statement->compound.statements;
6499         if (stmt != NULL) {
6500                 while (stmt->base.next != NULL)
6501                         stmt = stmt->base.next;
6502
6503                 if (stmt->kind == STATEMENT_EXPRESSION) {
6504                         type = stmt->expression.expression->base.type;
6505                 }
6506         } else if (warning.other) {
6507                 warningf(&expression->base.source_position, "empty statement expression ({})");
6508         }
6509         expression->base.type = type;
6510
6511         rem_anchor_token(')');
6512         expect(')', end_error);
6513
6514 end_error:
6515         return expression;
6516 }
6517
6518 /**
6519  * Parse a parenthesized expression.
6520  */
6521 static expression_t *parse_parenthesized_expression(void)
6522 {
6523         token_t const* const la1 = look_ahead(1);
6524         switch (la1->type) {
6525         case '{':
6526                 /* gcc extension: a statement expression */
6527                 return parse_statement_expression();
6528
6529         case T_IDENTIFIER:
6530                 if (is_typedef_symbol(la1->symbol)) {
6531         DECLARATION_START
6532                         return parse_cast();
6533                 }
6534         }
6535
6536         eat('(');
6537         add_anchor_token(')');
6538         expression_t *result = parse_expression();
6539         result->base.parenthesized = true;
6540         rem_anchor_token(')');
6541         expect(')', end_error);
6542
6543 end_error:
6544         return result;
6545 }
6546
6547 static expression_t *parse_function_keyword(void)
6548 {
6549         /* TODO */
6550
6551         if (current_function == NULL) {
6552                 errorf(HERE, "'__func__' used outside of a function");
6553         }
6554
6555         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6556         expression->base.type     = type_char_ptr;
6557         expression->funcname.kind = FUNCNAME_FUNCTION;
6558
6559         next_token();
6560
6561         return expression;
6562 }
6563
6564 static expression_t *parse_pretty_function_keyword(void)
6565 {
6566         if (current_function == NULL) {
6567                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6568         }
6569
6570         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6571         expression->base.type     = type_char_ptr;
6572         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6573
6574         eat(T___PRETTY_FUNCTION__);
6575
6576         return expression;
6577 }
6578
6579 static expression_t *parse_funcsig_keyword(void)
6580 {
6581         if (current_function == NULL) {
6582                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6583         }
6584
6585         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6586         expression->base.type     = type_char_ptr;
6587         expression->funcname.kind = FUNCNAME_FUNCSIG;
6588
6589         eat(T___FUNCSIG__);
6590
6591         return expression;
6592 }
6593
6594 static expression_t *parse_funcdname_keyword(void)
6595 {
6596         if (current_function == NULL) {
6597                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6598         }
6599
6600         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6601         expression->base.type     = type_char_ptr;
6602         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6603
6604         eat(T___FUNCDNAME__);
6605
6606         return expression;
6607 }
6608
6609 static designator_t *parse_designator(void)
6610 {
6611         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6612         result->source_position = *HERE;
6613
6614         if (token.type != T_IDENTIFIER) {
6615                 parse_error_expected("while parsing member designator",
6616                                      T_IDENTIFIER, NULL);
6617                 return NULL;
6618         }
6619         result->symbol = token.symbol;
6620         next_token();
6621
6622         designator_t *last_designator = result;
6623         while (true) {
6624                 if (next_if('.')) {
6625                         if (token.type != T_IDENTIFIER) {
6626                                 parse_error_expected("while parsing member designator",
6627                                                      T_IDENTIFIER, NULL);
6628                                 return NULL;
6629                         }
6630                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6631                         designator->source_position = *HERE;
6632                         designator->symbol          = token.symbol;
6633                         next_token();
6634
6635                         last_designator->next = designator;
6636                         last_designator       = designator;
6637                         continue;
6638                 }
6639                 if (next_if('[')) {
6640                         add_anchor_token(']');
6641                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6642                         designator->source_position = *HERE;
6643                         designator->array_index     = parse_expression();
6644                         rem_anchor_token(']');
6645                         expect(']', end_error);
6646                         if (designator->array_index == NULL) {
6647                                 return NULL;
6648                         }
6649
6650                         last_designator->next = designator;
6651                         last_designator       = designator;
6652                         continue;
6653                 }
6654                 break;
6655         }
6656
6657         return result;
6658 end_error:
6659         return NULL;
6660 }
6661
6662 /**
6663  * Parse the __builtin_offsetof() expression.
6664  */
6665 static expression_t *parse_offsetof(void)
6666 {
6667         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6668         expression->base.type    = type_size_t;
6669
6670         eat(T___builtin_offsetof);
6671
6672         expect('(', end_error);
6673         add_anchor_token(',');
6674         type_t *type = parse_typename();
6675         rem_anchor_token(',');
6676         expect(',', end_error);
6677         add_anchor_token(')');
6678         designator_t *designator = parse_designator();
6679         rem_anchor_token(')');
6680         expect(')', end_error);
6681
6682         expression->offsetofe.type       = type;
6683         expression->offsetofe.designator = designator;
6684
6685         type_path_t path;
6686         memset(&path, 0, sizeof(path));
6687         path.top_type = type;
6688         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6689
6690         descend_into_subtype(&path);
6691
6692         if (!walk_designator(&path, designator, true)) {
6693                 return create_invalid_expression();
6694         }
6695
6696         DEL_ARR_F(path.path);
6697
6698         return expression;
6699 end_error:
6700         return create_invalid_expression();
6701 }
6702
6703 /**
6704  * Parses a _builtin_va_start() expression.
6705  */
6706 static expression_t *parse_va_start(void)
6707 {
6708         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6709
6710         eat(T___builtin_va_start);
6711
6712         expect('(', end_error);
6713         add_anchor_token(',');
6714         expression->va_starte.ap = parse_assignment_expression();
6715         rem_anchor_token(',');
6716         expect(',', end_error);
6717         expression_t *const expr = parse_assignment_expression();
6718         if (expr->kind == EXPR_REFERENCE) {
6719                 entity_t *const entity = expr->reference.entity;
6720                 if (!current_function->base.type->function.variadic) {
6721                         errorf(&expr->base.source_position,
6722                                         "'va_start' used in non-variadic function");
6723                 } else if (entity->base.parent_scope != &current_function->parameters ||
6724                                 entity->base.next != NULL ||
6725                                 entity->kind != ENTITY_PARAMETER) {
6726                         errorf(&expr->base.source_position,
6727                                "second argument of 'va_start' must be last parameter of the current function");
6728                 } else {
6729                         expression->va_starte.parameter = &entity->variable;
6730                 }
6731                 expect(')', end_error);
6732                 return expression;
6733         }
6734         expect(')', end_error);
6735 end_error:
6736         return create_invalid_expression();
6737 }
6738
6739 /**
6740  * Parses a __builtin_va_arg() expression.
6741  */
6742 static expression_t *parse_va_arg(void)
6743 {
6744         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6745
6746         eat(T___builtin_va_arg);
6747
6748         expect('(', end_error);
6749         call_argument_t ap;
6750         ap.expression = parse_assignment_expression();
6751         expression->va_arge.ap = ap.expression;
6752         check_call_argument(type_valist, &ap, 1);
6753
6754         expect(',', end_error);
6755         expression->base.type = parse_typename();
6756         expect(')', end_error);
6757
6758         return expression;
6759 end_error:
6760         return create_invalid_expression();
6761 }
6762
6763 /**
6764  * Parses a __builtin_va_copy() expression.
6765  */
6766 static expression_t *parse_va_copy(void)
6767 {
6768         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6769
6770         eat(T___builtin_va_copy);
6771
6772         expect('(', end_error);
6773         expression_t *dst = parse_assignment_expression();
6774         assign_error_t error = semantic_assign(type_valist, dst);
6775         report_assign_error(error, type_valist, dst, "call argument 1",
6776                             &dst->base.source_position);
6777         expression->va_copye.dst = dst;
6778
6779         expect(',', end_error);
6780
6781         call_argument_t src;
6782         src.expression = parse_assignment_expression();
6783         check_call_argument(type_valist, &src, 2);
6784         expression->va_copye.src = src.expression;
6785         expect(')', end_error);
6786
6787         return expression;
6788 end_error:
6789         return create_invalid_expression();
6790 }
6791
6792 /**
6793  * Parses a __builtin_constant_p() expression.
6794  */
6795 static expression_t *parse_builtin_constant(void)
6796 {
6797         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6798
6799         eat(T___builtin_constant_p);
6800
6801         expect('(', end_error);
6802         add_anchor_token(')');
6803         expression->builtin_constant.value = parse_assignment_expression();
6804         rem_anchor_token(')');
6805         expect(')', end_error);
6806         expression->base.type = type_int;
6807
6808         return expression;
6809 end_error:
6810         return create_invalid_expression();
6811 }
6812
6813 /**
6814  * Parses a __builtin_types_compatible_p() expression.
6815  */
6816 static expression_t *parse_builtin_types_compatible(void)
6817 {
6818         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6819
6820         eat(T___builtin_types_compatible_p);
6821
6822         expect('(', end_error);
6823         add_anchor_token(')');
6824         add_anchor_token(',');
6825         expression->builtin_types_compatible.left = parse_typename();
6826         rem_anchor_token(',');
6827         expect(',', end_error);
6828         expression->builtin_types_compatible.right = parse_typename();
6829         rem_anchor_token(')');
6830         expect(')', end_error);
6831         expression->base.type = type_int;
6832
6833         return expression;
6834 end_error:
6835         return create_invalid_expression();
6836 }
6837
6838 /**
6839  * Parses a __builtin_is_*() compare expression.
6840  */
6841 static expression_t *parse_compare_builtin(void)
6842 {
6843         expression_t *expression;
6844
6845         switch (token.type) {
6846         case T___builtin_isgreater:
6847                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6848                 break;
6849         case T___builtin_isgreaterequal:
6850                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6851                 break;
6852         case T___builtin_isless:
6853                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6854                 break;
6855         case T___builtin_islessequal:
6856                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6857                 break;
6858         case T___builtin_islessgreater:
6859                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6860                 break;
6861         case T___builtin_isunordered:
6862                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6863                 break;
6864         default:
6865                 internal_errorf(HERE, "invalid compare builtin found");
6866         }
6867         expression->base.source_position = *HERE;
6868         next_token();
6869
6870         expect('(', end_error);
6871         expression->binary.left = parse_assignment_expression();
6872         expect(',', end_error);
6873         expression->binary.right = parse_assignment_expression();
6874         expect(')', end_error);
6875
6876         type_t *const orig_type_left  = expression->binary.left->base.type;
6877         type_t *const orig_type_right = expression->binary.right->base.type;
6878
6879         type_t *const type_left  = skip_typeref(orig_type_left);
6880         type_t *const type_right = skip_typeref(orig_type_right);
6881         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6882                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6883                         type_error_incompatible("invalid operands in comparison",
6884                                 &expression->base.source_position, orig_type_left, orig_type_right);
6885                 }
6886         } else {
6887                 semantic_comparison(&expression->binary);
6888         }
6889
6890         return expression;
6891 end_error:
6892         return create_invalid_expression();
6893 }
6894
6895 /**
6896  * Parses a MS assume() expression.
6897  */
6898 static expression_t *parse_assume(void)
6899 {
6900         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6901
6902         eat(T__assume);
6903
6904         expect('(', end_error);
6905         add_anchor_token(')');
6906         expression->unary.value = parse_assignment_expression();
6907         rem_anchor_token(')');
6908         expect(')', end_error);
6909
6910         expression->base.type = type_void;
6911         return expression;
6912 end_error:
6913         return create_invalid_expression();
6914 }
6915
6916 /**
6917  * Return the label for the current symbol or create a new one.
6918  */
6919 static label_t *get_label(void)
6920 {
6921         assert(token.type == T_IDENTIFIER);
6922         assert(current_function != NULL);
6923
6924         entity_t *label = get_entity(token.symbol, NAMESPACE_LABEL);
6925         /* If we find a local label, we already created the declaration. */
6926         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6927                 if (label->base.parent_scope != current_scope) {
6928                         assert(label->base.parent_scope->depth < current_scope->depth);
6929                         current_function->goto_to_outer = true;
6930                 }
6931         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6932                 /* There is no matching label in the same function, so create a new one. */
6933                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.symbol);
6934                 label_push(label);
6935         }
6936
6937         eat(T_IDENTIFIER);
6938         return &label->label;
6939 }
6940
6941 /**
6942  * Parses a GNU && label address expression.
6943  */
6944 static expression_t *parse_label_address(void)
6945 {
6946         source_position_t source_position = token.source_position;
6947         eat(T_ANDAND);
6948         if (token.type != T_IDENTIFIER) {
6949                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6950                 return create_invalid_expression();
6951         }
6952
6953         label_t *const label = get_label();
6954         label->used          = true;
6955         label->address_taken = true;
6956
6957         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6958         expression->base.source_position = source_position;
6959
6960         /* label address is treated as a void pointer */
6961         expression->base.type           = type_void_ptr;
6962         expression->label_address.label = label;
6963         return expression;
6964 }
6965
6966 /**
6967  * Parse a microsoft __noop expression.
6968  */
6969 static expression_t *parse_noop_expression(void)
6970 {
6971         /* the result is a (int)0 */
6972         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6973         literal->base.type            = type_int;
6974         literal->base.source_position = token.source_position;
6975         literal->literal.value.begin  = "__noop";
6976         literal->literal.value.size   = 6;
6977
6978         eat(T___noop);
6979
6980         if (token.type == '(') {
6981                 /* parse arguments */
6982                 eat('(');
6983                 add_anchor_token(')');
6984                 add_anchor_token(',');
6985
6986                 if (token.type != ')') do {
6987                         (void)parse_assignment_expression();
6988                 } while (next_if(','));
6989         }
6990         rem_anchor_token(',');
6991         rem_anchor_token(')');
6992         expect(')', end_error);
6993
6994 end_error:
6995         return literal;
6996 }
6997
6998 /**
6999  * Parses a primary expression.
7000  */
7001 static expression_t *parse_primary_expression(void)
7002 {
7003         switch (token.type) {
7004         case T_false:                        return parse_boolean_literal(false);
7005         case T_true:                         return parse_boolean_literal(true);
7006         case T_INTEGER:
7007         case T_INTEGER_OCTAL:
7008         case T_INTEGER_HEXADECIMAL:
7009         case T_FLOATINGPOINT:
7010         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
7011         case T_CHARACTER_CONSTANT:           return parse_character_constant();
7012         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7013         case T_STRING_LITERAL:
7014         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
7015         case T___FUNCTION__:
7016         case T___func__:                     return parse_function_keyword();
7017         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7018         case T___FUNCSIG__:                  return parse_funcsig_keyword();
7019         case T___FUNCDNAME__:                return parse_funcdname_keyword();
7020         case T___builtin_offsetof:           return parse_offsetof();
7021         case T___builtin_va_start:           return parse_va_start();
7022         case T___builtin_va_arg:             return parse_va_arg();
7023         case T___builtin_va_copy:            return parse_va_copy();
7024         case T___builtin_isgreater:
7025         case T___builtin_isgreaterequal:
7026         case T___builtin_isless:
7027         case T___builtin_islessequal:
7028         case T___builtin_islessgreater:
7029         case T___builtin_isunordered:        return parse_compare_builtin();
7030         case T___builtin_constant_p:         return parse_builtin_constant();
7031         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7032         case T__assume:                      return parse_assume();
7033         case T_ANDAND:
7034                 if (GNU_MODE)
7035                         return parse_label_address();
7036                 break;
7037
7038         case '(':                            return parse_parenthesized_expression();
7039         case T___noop:                       return parse_noop_expression();
7040
7041         /* Gracefully handle type names while parsing expressions. */
7042         case T_COLONCOLON:
7043                 return parse_reference();
7044         case T_IDENTIFIER:
7045                 if (!is_typedef_symbol(token.symbol)) {
7046                         return parse_reference();
7047                 }
7048                 /* FALLTHROUGH */
7049         DECLARATION_START {
7050                 source_position_t const  pos = *HERE;
7051                 declaration_specifiers_t specifiers;
7052                 parse_declaration_specifiers(&specifiers);
7053                 type_t const *const type = parse_abstract_declarator(specifiers.type);
7054                 errorf(&pos, "encountered type '%T' while parsing expression", type);
7055                 return create_invalid_expression();
7056         }
7057         }
7058
7059         errorf(HERE, "unexpected token %K, expected an expression", &token);
7060         eat_until_anchor();
7061         return create_invalid_expression();
7062 }
7063
7064 static expression_t *parse_array_expression(expression_t *left)
7065 {
7066         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7067         array_access_expression_t *const arr  = &expr->array_access;
7068
7069         eat('[');
7070         add_anchor_token(']');
7071
7072         expression_t *const inside = parse_expression();
7073
7074         type_t *const orig_type_left   = left->base.type;
7075         type_t *const orig_type_inside = inside->base.type;
7076
7077         type_t *const type_left   = skip_typeref(orig_type_left);
7078         type_t *const type_inside = skip_typeref(orig_type_inside);
7079
7080         expression_t *ref;
7081         expression_t *idx;
7082         type_t       *idx_type;
7083         type_t       *res_type;
7084         if (is_type_pointer(type_left)) {
7085                 ref      = left;
7086                 idx      = inside;
7087                 idx_type = type_inside;
7088                 res_type = type_left->pointer.points_to;
7089                 goto check_idx;
7090         } else if (is_type_pointer(type_inside)) {
7091                 arr->flipped = true;
7092                 ref      = inside;
7093                 idx      = left;
7094                 idx_type = type_left;
7095                 res_type = type_inside->pointer.points_to;
7096 check_idx:
7097                 res_type = automatic_type_conversion(res_type);
7098                 if (!is_type_integer(idx_type)) {
7099                         errorf(&idx->base.source_position, "array subscript must have integer type");
7100                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR) && warning.char_subscripts) {
7101                         warningf(&idx->base.source_position, "array subscript has char type");
7102                 }
7103         } else {
7104                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7105                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
7106                 }
7107                 res_type = type_error_type;
7108                 ref      = left;
7109                 idx      = inside;
7110         }
7111
7112         arr->array_ref = ref;
7113         arr->index     = idx;
7114         arr->base.type = res_type;
7115
7116         rem_anchor_token(']');
7117         expect(']', end_error);
7118 end_error:
7119         return expr;
7120 }
7121
7122 static expression_t *parse_typeprop(expression_kind_t const kind)
7123 {
7124         expression_t  *tp_expression = allocate_expression_zero(kind);
7125         tp_expression->base.type     = type_size_t;
7126
7127         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7128
7129         /* we only refer to a type property, mark this case */
7130         bool old     = in_type_prop;
7131         in_type_prop = true;
7132
7133         type_t       *orig_type;
7134         expression_t *expression;
7135         if (token.type == '(' && is_declaration_specifier(look_ahead(1))) {
7136                 next_token();
7137                 add_anchor_token(')');
7138                 orig_type = parse_typename();
7139                 rem_anchor_token(')');
7140                 expect(')', end_error);
7141
7142                 if (token.type == '{') {
7143                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7144                          * starting with a compound literal */
7145                         expression = parse_compound_literal(orig_type);
7146                         goto typeprop_expression;
7147                 }
7148         } else {
7149                 expression = parse_subexpression(PREC_UNARY);
7150
7151 typeprop_expression:
7152                 tp_expression->typeprop.tp_expression = expression;
7153
7154                 orig_type = revert_automatic_type_conversion(expression);
7155                 expression->base.type = orig_type;
7156         }
7157
7158         tp_expression->typeprop.type   = orig_type;
7159         type_t const* const type       = skip_typeref(orig_type);
7160         char   const*       wrong_type = NULL;
7161         if (is_type_incomplete(type)) {
7162                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7163                         wrong_type = "incomplete";
7164         } else if (type->kind == TYPE_FUNCTION) {
7165                 if (GNU_MODE) {
7166                         /* function types are allowed (and return 1) */
7167                         if (warning.other) {
7168                                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7169                                 warningf(&tp_expression->base.source_position,
7170                                          "%s expression with function argument returns invalid result", what);
7171                         }
7172                 } else {
7173                         wrong_type = "function";
7174                 }
7175         } else {
7176                 if (is_type_incomplete(type))
7177                         wrong_type = "incomplete";
7178         }
7179         if (type->kind == TYPE_BITFIELD)
7180                 wrong_type = "bitfield";
7181
7182         if (wrong_type != NULL) {
7183                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7184                 errorf(&tp_expression->base.source_position,
7185                                 "operand of %s expression must not be of %s type '%T'",
7186                                 what, wrong_type, orig_type);
7187         }
7188
7189 end_error:
7190         in_type_prop = old;
7191         return tp_expression;
7192 }
7193
7194 static expression_t *parse_sizeof(void)
7195 {
7196         return parse_typeprop(EXPR_SIZEOF);
7197 }
7198
7199 static expression_t *parse_alignof(void)
7200 {
7201         return parse_typeprop(EXPR_ALIGNOF);
7202 }
7203
7204 static expression_t *parse_select_expression(expression_t *addr)
7205 {
7206         assert(token.type == '.' || token.type == T_MINUSGREATER);
7207         bool select_left_arrow = (token.type == T_MINUSGREATER);
7208         source_position_t const pos = *HERE;
7209         next_token();
7210
7211         if (token.type != T_IDENTIFIER) {
7212                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7213                 return create_invalid_expression();
7214         }
7215         symbol_t *symbol = token.symbol;
7216         next_token();
7217
7218         type_t *const orig_type = addr->base.type;
7219         type_t *const type      = skip_typeref(orig_type);
7220
7221         type_t *type_left;
7222         bool    saw_error = false;
7223         if (is_type_pointer(type)) {
7224                 if (!select_left_arrow) {
7225                         errorf(&pos,
7226                                "request for member '%Y' in something not a struct or union, but '%T'",
7227                                symbol, orig_type);
7228                         saw_error = true;
7229                 }
7230                 type_left = skip_typeref(type->pointer.points_to);
7231         } else {
7232                 if (select_left_arrow && is_type_valid(type)) {
7233                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7234                         saw_error = true;
7235                 }
7236                 type_left = type;
7237         }
7238
7239         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7240             type_left->kind != TYPE_COMPOUND_UNION) {
7241
7242                 if (is_type_valid(type_left) && !saw_error) {
7243                         errorf(&pos,
7244                                "request for member '%Y' in something not a struct or union, but '%T'",
7245                                symbol, type_left);
7246                 }
7247                 return create_invalid_expression();
7248         }
7249
7250         compound_t *compound = type_left->compound.compound;
7251         if (!compound->complete) {
7252                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7253                        symbol, type_left);
7254                 return create_invalid_expression();
7255         }
7256
7257         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7258         expression_t      *result     =
7259                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7260
7261         if (result == NULL) {
7262                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7263                 return create_invalid_expression();
7264         }
7265
7266         return result;
7267 }
7268
7269 static void check_call_argument(type_t          *expected_type,
7270                                 call_argument_t *argument, unsigned pos)
7271 {
7272         type_t         *expected_type_skip = skip_typeref(expected_type);
7273         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7274         expression_t   *arg_expr           = argument->expression;
7275         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7276
7277         /* handle transparent union gnu extension */
7278         if (is_type_union(expected_type_skip)
7279                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7280                 compound_t *union_decl  = expected_type_skip->compound.compound;
7281                 type_t     *best_type   = NULL;
7282                 entity_t   *entry       = union_decl->members.entities;
7283                 for ( ; entry != NULL; entry = entry->base.next) {
7284                         assert(is_declaration(entry));
7285                         type_t *decl_type = entry->declaration.type;
7286                         error = semantic_assign(decl_type, arg_expr);
7287                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7288                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7289                                 continue;
7290
7291                         if (error == ASSIGN_SUCCESS) {
7292                                 best_type = decl_type;
7293                         } else if (best_type == NULL) {
7294                                 best_type = decl_type;
7295                         }
7296                 }
7297
7298                 if (best_type != NULL) {
7299                         expected_type = best_type;
7300                 }
7301         }
7302
7303         error                = semantic_assign(expected_type, arg_expr);
7304         argument->expression = create_implicit_cast(arg_expr, expected_type);
7305
7306         if (error != ASSIGN_SUCCESS) {
7307                 /* report exact scope in error messages (like "in argument 3") */
7308                 char buf[64];
7309                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7310                 report_assign_error(error, expected_type, arg_expr, buf,
7311                                     &arg_expr->base.source_position);
7312         } else if (warning.traditional || warning.conversion) {
7313                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7314                 if (!types_compatible(expected_type_skip, promoted_type) &&
7315                     !types_compatible(expected_type_skip, type_void_ptr) &&
7316                     !types_compatible(type_void_ptr,      promoted_type)) {
7317                         /* Deliberately show the skipped types in this warning */
7318                         warningf(&arg_expr->base.source_position,
7319                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7320                                 pos, expected_type_skip, promoted_type);
7321                 }
7322         }
7323 }
7324
7325 /**
7326  * Handle the semantic restrictions of builtin calls
7327  */
7328 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7329         switch (call->function->reference.entity->function.btk) {
7330                 case bk_gnu_builtin_return_address:
7331                 case bk_gnu_builtin_frame_address: {
7332                         /* argument must be constant */
7333                         call_argument_t *argument = call->arguments;
7334
7335                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7336                                 errorf(&call->base.source_position,
7337                                        "argument of '%Y' must be a constant expression",
7338                                        call->function->reference.entity->base.symbol);
7339                         }
7340                         break;
7341                 }
7342                 case bk_gnu_builtin_object_size:
7343                         if (call->arguments == NULL)
7344                                 break;
7345
7346                         call_argument_t *arg = call->arguments->next;
7347                         if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7348                                 errorf(&call->base.source_position,
7349                                            "second argument of '%Y' must be a constant expression",
7350                                            call->function->reference.entity->base.symbol);
7351                         }
7352                         break;
7353                 case bk_gnu_builtin_prefetch:
7354                         /* second and third argument must be constant if existent */
7355                         if (call->arguments == NULL)
7356                                 break;
7357                         call_argument_t *rw = call->arguments->next;
7358                         call_argument_t *locality = NULL;
7359
7360                         if (rw != NULL) {
7361                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7362                                         errorf(&call->base.source_position,
7363                                                "second argument of '%Y' must be a constant expression",
7364                                                call->function->reference.entity->base.symbol);
7365                                 }
7366                                 locality = rw->next;
7367                         }
7368                         if (locality != NULL) {
7369                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7370                                         errorf(&call->base.source_position,
7371                                                "third argument of '%Y' must be a constant expression",
7372                                                call->function->reference.entity->base.symbol);
7373                                 }
7374                                 locality = rw->next;
7375                         }
7376                         break;
7377                 default:
7378                         break;
7379         }
7380 }
7381
7382 /**
7383  * Parse a call expression, ie. expression '( ... )'.
7384  *
7385  * @param expression  the function address
7386  */
7387 static expression_t *parse_call_expression(expression_t *expression)
7388 {
7389         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7390         call_expression_t *call   = &result->call;
7391         call->function            = expression;
7392
7393         type_t *const orig_type = expression->base.type;
7394         type_t *const type      = skip_typeref(orig_type);
7395
7396         function_type_t *function_type = NULL;
7397         if (is_type_pointer(type)) {
7398                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7399
7400                 if (is_type_function(to_type)) {
7401                         function_type   = &to_type->function;
7402                         call->base.type = function_type->return_type;
7403                 }
7404         }
7405
7406         if (function_type == NULL && is_type_valid(type)) {
7407                 errorf(HERE,
7408                        "called object '%E' (type '%T') is not a pointer to a function",
7409                        expression, orig_type);
7410         }
7411
7412         /* parse arguments */
7413         eat('(');
7414         add_anchor_token(')');
7415         add_anchor_token(',');
7416
7417         if (token.type != ')') {
7418                 call_argument_t **anchor = &call->arguments;
7419                 do {
7420                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7421                         argument->expression = parse_assignment_expression();
7422
7423                         *anchor = argument;
7424                         anchor  = &argument->next;
7425                 } while (next_if(','));
7426         }
7427         rem_anchor_token(',');
7428         rem_anchor_token(')');
7429         expect(')', end_error);
7430
7431         if (function_type == NULL)
7432                 return result;
7433
7434         /* check type and count of call arguments */
7435         function_parameter_t *parameter = function_type->parameters;
7436         call_argument_t      *argument  = call->arguments;
7437         if (!function_type->unspecified_parameters) {
7438                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7439                                 parameter = parameter->next, argument = argument->next) {
7440                         check_call_argument(parameter->type, argument, ++pos);
7441                 }
7442
7443                 if (parameter != NULL) {
7444                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7445                 } else if (argument != NULL && !function_type->variadic) {
7446                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7447                 }
7448         }
7449
7450         /* do default promotion for other arguments */
7451         for (; argument != NULL; argument = argument->next) {
7452                 type_t *argument_type = argument->expression->base.type;
7453                 if (!is_type_object(skip_typeref(argument_type))) {
7454                         errorf(&argument->expression->base.source_position,
7455                                "call argument '%E' must not be void", argument->expression);
7456                 }
7457
7458                 argument_type = get_default_promoted_type(argument_type);
7459
7460                 argument->expression
7461                         = create_implicit_cast(argument->expression, argument_type);
7462         }
7463
7464         check_format(call);
7465
7466         if (warning.aggregate_return &&
7467             is_type_compound(skip_typeref(function_type->return_type))) {
7468                 warningf(&expression->base.source_position,
7469                          "function call has aggregate value");
7470         }
7471
7472         if (expression->kind == EXPR_REFERENCE) {
7473                 reference_expression_t *reference = &expression->reference;
7474                 if (reference->entity->kind == ENTITY_FUNCTION &&
7475                     reference->entity->function.btk != bk_none)
7476                         handle_builtin_argument_restrictions(call);
7477         }
7478
7479 end_error:
7480         return result;
7481 }
7482
7483 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7484
7485 static bool same_compound_type(const type_t *type1, const type_t *type2)
7486 {
7487         return
7488                 is_type_compound(type1) &&
7489                 type1->kind == type2->kind &&
7490                 type1->compound.compound == type2->compound.compound;
7491 }
7492
7493 static expression_t const *get_reference_address(expression_t const *expr)
7494 {
7495         bool regular_take_address = true;
7496         for (;;) {
7497                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7498                         expr = expr->unary.value;
7499                 } else {
7500                         regular_take_address = false;
7501                 }
7502
7503                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7504                         break;
7505
7506                 expr = expr->unary.value;
7507         }
7508
7509         if (expr->kind != EXPR_REFERENCE)
7510                 return NULL;
7511
7512         /* special case for functions which are automatically converted to a
7513          * pointer to function without an extra TAKE_ADDRESS operation */
7514         if (!regular_take_address &&
7515                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7516                 return NULL;
7517         }
7518
7519         return expr;
7520 }
7521
7522 static void warn_reference_address_as_bool(expression_t const* expr)
7523 {
7524         if (!warning.address)
7525                 return;
7526
7527         expr = get_reference_address(expr);
7528         if (expr != NULL) {
7529                 source_position_t const *const pos = &expr->base.source_position;
7530                 entity_t          const *const ent = expr->reference.entity;
7531                 warningf(pos, "the address of '%N' will always evaluate as 'true'", ent);
7532         }
7533 }
7534
7535 static void warn_assignment_in_condition(const expression_t *const expr)
7536 {
7537         if (!warning.parentheses)
7538                 return;
7539         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7540                 return;
7541         if (expr->base.parenthesized)
7542                 return;
7543         warningf(&expr->base.source_position,
7544                         "suggest parentheses around assignment used as truth value");
7545 }
7546
7547 static void semantic_condition(expression_t const *const expr,
7548                                char const *const context)
7549 {
7550         type_t *const type = skip_typeref(expr->base.type);
7551         if (is_type_scalar(type)) {
7552                 warn_reference_address_as_bool(expr);
7553                 warn_assignment_in_condition(expr);
7554         } else if (is_type_valid(type)) {
7555                 errorf(&expr->base.source_position,
7556                                 "%s must have scalar type", context);
7557         }
7558 }
7559
7560 /**
7561  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7562  *
7563  * @param expression  the conditional expression
7564  */
7565 static expression_t *parse_conditional_expression(expression_t *expression)
7566 {
7567         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7568
7569         conditional_expression_t *conditional = &result->conditional;
7570         conditional->condition                = expression;
7571
7572         eat('?');
7573         add_anchor_token(':');
7574
7575         /* §6.5.15:2  The first operand shall have scalar type. */
7576         semantic_condition(expression, "condition of conditional operator");
7577
7578         expression_t *true_expression = expression;
7579         bool          gnu_cond = false;
7580         if (GNU_MODE && token.type == ':') {
7581                 gnu_cond = true;
7582         } else {
7583                 true_expression = parse_expression();
7584         }
7585         rem_anchor_token(':');
7586         expect(':', end_error);
7587 end_error:;
7588         expression_t *false_expression =
7589                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7590
7591         type_t *const orig_true_type  = true_expression->base.type;
7592         type_t *const orig_false_type = false_expression->base.type;
7593         type_t *const true_type       = skip_typeref(orig_true_type);
7594         type_t *const false_type      = skip_typeref(orig_false_type);
7595
7596         /* 6.5.15.3 */
7597         type_t *result_type;
7598         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7599                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7600                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7601                 if (true_expression->kind == EXPR_UNARY_THROW) {
7602                         result_type = false_type;
7603                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7604                         result_type = true_type;
7605                 } else {
7606                         if (warning.other && (
7607                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7608                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7609                                         )) {
7610                                 warningf(&conditional->base.source_position,
7611                                                 "ISO C forbids conditional expression with only one void side");
7612                         }
7613                         result_type = type_void;
7614                 }
7615         } else if (is_type_arithmetic(true_type)
7616                    && is_type_arithmetic(false_type)) {
7617                 result_type = semantic_arithmetic(true_type, false_type);
7618         } else if (same_compound_type(true_type, false_type)) {
7619                 /* just take 1 of the 2 types */
7620                 result_type = true_type;
7621         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7622                 type_t *pointer_type;
7623                 type_t *other_type;
7624                 expression_t *other_expression;
7625                 if (is_type_pointer(true_type) &&
7626                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7627                         pointer_type     = true_type;
7628                         other_type       = false_type;
7629                         other_expression = false_expression;
7630                 } else {
7631                         pointer_type     = false_type;
7632                         other_type       = true_type;
7633                         other_expression = true_expression;
7634                 }
7635
7636                 if (is_null_pointer_constant(other_expression)) {
7637                         result_type = pointer_type;
7638                 } else if (is_type_pointer(other_type)) {
7639                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7640                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7641
7642                         type_t *to;
7643                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7644                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7645                                 to = type_void;
7646                         } else if (types_compatible(get_unqualified_type(to1),
7647                                                     get_unqualified_type(to2))) {
7648                                 to = to1;
7649                         } else {
7650                                 if (warning.other) {
7651                                         warningf(&conditional->base.source_position,
7652                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7653                                                         true_type, false_type);
7654                                 }
7655                                 to = type_void;
7656                         }
7657
7658                         type_t *const type =
7659                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7660                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7661                 } else if (is_type_integer(other_type)) {
7662                         if (warning.other) {
7663                                 warningf(&conditional->base.source_position,
7664                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7665                         }
7666                         result_type = pointer_type;
7667                 } else {
7668                         goto types_incompatible;
7669                 }
7670         } else {
7671 types_incompatible:
7672                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7673                         type_error_incompatible("while parsing conditional",
7674                                                 &conditional->base.source_position, true_type,
7675                                                 false_type);
7676                 }
7677                 result_type = type_error_type;
7678         }
7679
7680         conditional->true_expression
7681                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7682         conditional->false_expression
7683                 = create_implicit_cast(false_expression, result_type);
7684         conditional->base.type = result_type;
7685         return result;
7686 }
7687
7688 /**
7689  * Parse an extension expression.
7690  */
7691 static expression_t *parse_extension(void)
7692 {
7693         eat(T___extension__);
7694
7695         bool old_gcc_extension   = in_gcc_extension;
7696         in_gcc_extension         = true;
7697         expression_t *expression = parse_subexpression(PREC_UNARY);
7698         in_gcc_extension         = old_gcc_extension;
7699         return expression;
7700 }
7701
7702 /**
7703  * Parse a __builtin_classify_type() expression.
7704  */
7705 static expression_t *parse_builtin_classify_type(void)
7706 {
7707         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7708         result->base.type    = type_int;
7709
7710         eat(T___builtin_classify_type);
7711
7712         expect('(', end_error);
7713         add_anchor_token(')');
7714         expression_t *expression = parse_expression();
7715         rem_anchor_token(')');
7716         expect(')', end_error);
7717         result->classify_type.type_expression = expression;
7718
7719         return result;
7720 end_error:
7721         return create_invalid_expression();
7722 }
7723
7724 /**
7725  * Parse a delete expression
7726  * ISO/IEC 14882:1998(E) §5.3.5
7727  */
7728 static expression_t *parse_delete(void)
7729 {
7730         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7731         result->base.type          = type_void;
7732
7733         eat(T_delete);
7734
7735         if (next_if('[')) {
7736                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7737                 expect(']', end_error);
7738 end_error:;
7739         }
7740
7741         expression_t *const value = parse_subexpression(PREC_CAST);
7742         result->unary.value = value;
7743
7744         type_t *const type = skip_typeref(value->base.type);
7745         if (!is_type_pointer(type)) {
7746                 if (is_type_valid(type)) {
7747                         errorf(&value->base.source_position,
7748                                         "operand of delete must have pointer type");
7749                 }
7750         } else if (warning.other &&
7751                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7752                 warningf(&value->base.source_position,
7753                                 "deleting 'void*' is undefined");
7754         }
7755
7756         return result;
7757 }
7758
7759 /**
7760  * Parse a throw expression
7761  * ISO/IEC 14882:1998(E) §15:1
7762  */
7763 static expression_t *parse_throw(void)
7764 {
7765         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7766         result->base.type          = type_void;
7767
7768         eat(T_throw);
7769
7770         expression_t *value = NULL;
7771         switch (token.type) {
7772                 EXPRESSION_START {
7773                         value = parse_assignment_expression();
7774                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7775                         type_t *const orig_type = value->base.type;
7776                         type_t *const type      = skip_typeref(orig_type);
7777                         if (is_type_incomplete(type)) {
7778                                 errorf(&value->base.source_position,
7779                                                 "cannot throw object of incomplete type '%T'", orig_type);
7780                         } else if (is_type_pointer(type)) {
7781                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7782                                 if (is_type_incomplete(points_to) &&
7783                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7784                                         errorf(&value->base.source_position,
7785                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7786                                 }
7787                         }
7788                 }
7789
7790                 default:
7791                         break;
7792         }
7793         result->unary.value = value;
7794
7795         return result;
7796 }
7797
7798 static bool check_pointer_arithmetic(const source_position_t *source_position,
7799                                      type_t *pointer_type,
7800                                      type_t *orig_pointer_type)
7801 {
7802         type_t *points_to = pointer_type->pointer.points_to;
7803         points_to = skip_typeref(points_to);
7804
7805         if (is_type_incomplete(points_to)) {
7806                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7807                         errorf(source_position,
7808                                "arithmetic with pointer to incomplete type '%T' not allowed",
7809                                orig_pointer_type);
7810                         return false;
7811                 } else if (warning.pointer_arith) {
7812                         warningf(source_position,
7813                                  "pointer of type '%T' used in arithmetic",
7814                                  orig_pointer_type);
7815                 }
7816         } else if (is_type_function(points_to)) {
7817                 if (!GNU_MODE) {
7818                         errorf(source_position,
7819                                "arithmetic with pointer to function type '%T' not allowed",
7820                                orig_pointer_type);
7821                         return false;
7822                 } else if (warning.pointer_arith) {
7823                         warningf(source_position,
7824                                  "pointer to a function '%T' used in arithmetic",
7825                                  orig_pointer_type);
7826                 }
7827         }
7828         return true;
7829 }
7830
7831 static bool is_lvalue(const expression_t *expression)
7832 {
7833         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7834         switch (expression->kind) {
7835         case EXPR_ARRAY_ACCESS:
7836         case EXPR_COMPOUND_LITERAL:
7837         case EXPR_REFERENCE:
7838         case EXPR_SELECT:
7839         case EXPR_UNARY_DEREFERENCE:
7840                 return true;
7841
7842         default: {
7843                 type_t *type = skip_typeref(expression->base.type);
7844                 return
7845                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7846                         is_type_reference(type) ||
7847                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7848                          * error before, which maybe prevented properly recognizing it as
7849                          * lvalue. */
7850                         !is_type_valid(type);
7851         }
7852         }
7853 }
7854
7855 static void semantic_incdec(unary_expression_t *expression)
7856 {
7857         type_t *const orig_type = expression->value->base.type;
7858         type_t *const type      = skip_typeref(orig_type);
7859         if (is_type_pointer(type)) {
7860                 if (!check_pointer_arithmetic(&expression->base.source_position,
7861                                               type, orig_type)) {
7862                         return;
7863                 }
7864         } else if (!is_type_real(type) && is_type_valid(type)) {
7865                 /* TODO: improve error message */
7866                 errorf(&expression->base.source_position,
7867                        "operation needs an arithmetic or pointer type");
7868                 return;
7869         }
7870         if (!is_lvalue(expression->value)) {
7871                 /* TODO: improve error message */
7872                 errorf(&expression->base.source_position, "lvalue required as operand");
7873         }
7874         expression->base.type = orig_type;
7875 }
7876
7877 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7878 {
7879         type_t *const orig_type = expression->value->base.type;
7880         type_t *const type      = skip_typeref(orig_type);
7881         if (!is_type_arithmetic(type)) {
7882                 if (is_type_valid(type)) {
7883                         /* TODO: improve error message */
7884                         errorf(&expression->base.source_position,
7885                                 "operation needs an arithmetic type");
7886                 }
7887                 return;
7888         }
7889
7890         expression->base.type = orig_type;
7891 }
7892
7893 static void semantic_unexpr_plus(unary_expression_t *expression)
7894 {
7895         semantic_unexpr_arithmetic(expression);
7896         if (warning.traditional)
7897                 warningf(&expression->base.source_position,
7898                         "traditional C rejects the unary plus operator");
7899 }
7900
7901 static void semantic_not(unary_expression_t *expression)
7902 {
7903         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7904         semantic_condition(expression->value, "operand of !");
7905         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7906 }
7907
7908 static void semantic_unexpr_integer(unary_expression_t *expression)
7909 {
7910         type_t *const orig_type = expression->value->base.type;
7911         type_t *const type      = skip_typeref(orig_type);
7912         if (!is_type_integer(type)) {
7913                 if (is_type_valid(type)) {
7914                         errorf(&expression->base.source_position,
7915                                "operand of ~ must be of integer type");
7916                 }
7917                 return;
7918         }
7919
7920         expression->base.type = orig_type;
7921 }
7922
7923 static void semantic_dereference(unary_expression_t *expression)
7924 {
7925         type_t *const orig_type = expression->value->base.type;
7926         type_t *const type      = skip_typeref(orig_type);
7927         if (!is_type_pointer(type)) {
7928                 if (is_type_valid(type)) {
7929                         errorf(&expression->base.source_position,
7930                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7931                 }
7932                 return;
7933         }
7934
7935         type_t *result_type   = type->pointer.points_to;
7936         result_type           = automatic_type_conversion(result_type);
7937         expression->base.type = result_type;
7938 }
7939
7940 /**
7941  * Record that an address is taken (expression represents an lvalue).
7942  *
7943  * @param expression       the expression
7944  * @param may_be_register  if true, the expression might be an register
7945  */
7946 static void set_address_taken(expression_t *expression, bool may_be_register)
7947 {
7948         if (expression->kind != EXPR_REFERENCE)
7949                 return;
7950
7951         entity_t *const entity = expression->reference.entity;
7952
7953         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7954                 return;
7955
7956         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7957                         && !may_be_register) {
7958                 source_position_t const *const pos = &expression->base.source_position;
7959                 errorf(pos, "address of register '%N' requested", entity);
7960         }
7961
7962         if (entity->kind == ENTITY_VARIABLE) {
7963                 entity->variable.address_taken = true;
7964         } else {
7965                 assert(entity->kind == ENTITY_PARAMETER);
7966                 entity->parameter.address_taken = true;
7967         }
7968 }
7969
7970 /**
7971  * Check the semantic of the address taken expression.
7972  */
7973 static void semantic_take_addr(unary_expression_t *expression)
7974 {
7975         expression_t *value = expression->value;
7976         value->base.type    = revert_automatic_type_conversion(value);
7977
7978         type_t *orig_type = value->base.type;
7979         type_t *type      = skip_typeref(orig_type);
7980         if (!is_type_valid(type))
7981                 return;
7982
7983         /* §6.5.3.2 */
7984         if (!is_lvalue(value)) {
7985                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7986         }
7987         if (type->kind == TYPE_BITFIELD) {
7988                 errorf(&expression->base.source_position,
7989                        "'&' not allowed on object with bitfield type '%T'",
7990                        type);
7991         }
7992
7993         set_address_taken(value, false);
7994
7995         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7996 }
7997
7998 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
7999 static expression_t *parse_##unexpression_type(void)                         \
8000 {                                                                            \
8001         expression_t *unary_expression                                           \
8002                 = allocate_expression_zero(unexpression_type);                       \
8003         eat(token_type);                                                         \
8004         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
8005                                                                                  \
8006         sfunc(&unary_expression->unary);                                         \
8007                                                                                  \
8008         return unary_expression;                                                 \
8009 }
8010
8011 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8012                                semantic_unexpr_arithmetic)
8013 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8014                                semantic_unexpr_plus)
8015 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8016                                semantic_not)
8017 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8018                                semantic_dereference)
8019 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8020                                semantic_take_addr)
8021 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8022                                semantic_unexpr_integer)
8023 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8024                                semantic_incdec)
8025 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8026                                semantic_incdec)
8027
8028 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8029                                                sfunc)                         \
8030 static expression_t *parse_##unexpression_type(expression_t *left)            \
8031 {                                                                             \
8032         expression_t *unary_expression                                            \
8033                 = allocate_expression_zero(unexpression_type);                        \
8034         eat(token_type);                                                          \
8035         unary_expression->unary.value = left;                                     \
8036                                                                                   \
8037         sfunc(&unary_expression->unary);                                          \
8038                                                                               \
8039         return unary_expression;                                                  \
8040 }
8041
8042 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8043                                        EXPR_UNARY_POSTFIX_INCREMENT,
8044                                        semantic_incdec)
8045 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8046                                        EXPR_UNARY_POSTFIX_DECREMENT,
8047                                        semantic_incdec)
8048
8049 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8050 {
8051         /* TODO: handle complex + imaginary types */
8052
8053         type_left  = get_unqualified_type(type_left);
8054         type_right = get_unqualified_type(type_right);
8055
8056         /* §6.3.1.8 Usual arithmetic conversions */
8057         if (type_left == type_long_double || type_right == type_long_double) {
8058                 return type_long_double;
8059         } else if (type_left == type_double || type_right == type_double) {
8060                 return type_double;
8061         } else if (type_left == type_float || type_right == type_float) {
8062                 return type_float;
8063         }
8064
8065         type_left  = promote_integer(type_left);
8066         type_right = promote_integer(type_right);
8067
8068         if (type_left == type_right)
8069                 return type_left;
8070
8071         bool const signed_left  = is_type_signed(type_left);
8072         bool const signed_right = is_type_signed(type_right);
8073         int const  rank_left    = get_rank(type_left);
8074         int const  rank_right   = get_rank(type_right);
8075
8076         if (signed_left == signed_right)
8077                 return rank_left >= rank_right ? type_left : type_right;
8078
8079         int     s_rank;
8080         int     u_rank;
8081         type_t *s_type;
8082         type_t *u_type;
8083         if (signed_left) {
8084                 s_rank = rank_left;
8085                 s_type = type_left;
8086                 u_rank = rank_right;
8087                 u_type = type_right;
8088         } else {
8089                 s_rank = rank_right;
8090                 s_type = type_right;
8091                 u_rank = rank_left;
8092                 u_type = type_left;
8093         }
8094
8095         if (u_rank >= s_rank)
8096                 return u_type;
8097
8098         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8099          * easier here... */
8100         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8101                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8102                 return s_type;
8103
8104         switch (s_rank) {
8105                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8106                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8107                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8108
8109                 default: panic("invalid atomic type");
8110         }
8111 }
8112
8113 /**
8114  * Check the semantic restrictions for a binary expression.
8115  */
8116 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8117 {
8118         expression_t *const left            = expression->left;
8119         expression_t *const right           = expression->right;
8120         type_t       *const orig_type_left  = left->base.type;
8121         type_t       *const orig_type_right = right->base.type;
8122         type_t       *const type_left       = skip_typeref(orig_type_left);
8123         type_t       *const type_right      = skip_typeref(orig_type_right);
8124
8125         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8126                 /* TODO: improve error message */
8127                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8128                         errorf(&expression->base.source_position,
8129                                "operation needs arithmetic types");
8130                 }
8131                 return;
8132         }
8133
8134         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8135         expression->left      = create_implicit_cast(left, arithmetic_type);
8136         expression->right     = create_implicit_cast(right, arithmetic_type);
8137         expression->base.type = arithmetic_type;
8138 }
8139
8140 static void semantic_binexpr_integer(binary_expression_t *const expression)
8141 {
8142         expression_t *const left            = expression->left;
8143         expression_t *const right           = expression->right;
8144         type_t       *const orig_type_left  = left->base.type;
8145         type_t       *const orig_type_right = right->base.type;
8146         type_t       *const type_left       = skip_typeref(orig_type_left);
8147         type_t       *const type_right      = skip_typeref(orig_type_right);
8148
8149         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8150                 /* TODO: improve error message */
8151                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8152                         errorf(&expression->base.source_position,
8153                                "operation needs integer types");
8154                 }
8155                 return;
8156         }
8157
8158         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8159         expression->left      = create_implicit_cast(left, result_type);
8160         expression->right     = create_implicit_cast(right, result_type);
8161         expression->base.type = result_type;
8162 }
8163
8164 static void warn_div_by_zero(binary_expression_t const *const expression)
8165 {
8166         if (!warning.div_by_zero ||
8167             !is_type_integer(expression->base.type))
8168                 return;
8169
8170         expression_t const *const right = expression->right;
8171         /* The type of the right operand can be different for /= */
8172         if (is_type_integer(right->base.type)                    &&
8173             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8174             !fold_constant_to_bool(right)) {
8175                 warningf(&expression->base.source_position, "division by zero");
8176         }
8177 }
8178
8179 /**
8180  * Check the semantic restrictions for a div/mod expression.
8181  */
8182 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8183 {
8184         semantic_binexpr_arithmetic(expression);
8185         warn_div_by_zero(expression);
8186 }
8187
8188 static void warn_addsub_in_shift(const expression_t *const expr)
8189 {
8190         if (expr->base.parenthesized)
8191                 return;
8192
8193         char op;
8194         switch (expr->kind) {
8195                 case EXPR_BINARY_ADD: op = '+'; break;
8196                 case EXPR_BINARY_SUB: op = '-'; break;
8197                 default:              return;
8198         }
8199
8200         warningf(&expr->base.source_position,
8201                         "suggest parentheses around '%c' inside shift", op);
8202 }
8203
8204 static bool semantic_shift(binary_expression_t *expression)
8205 {
8206         expression_t *const left            = expression->left;
8207         expression_t *const right           = expression->right;
8208         type_t       *const orig_type_left  = left->base.type;
8209         type_t       *const orig_type_right = right->base.type;
8210         type_t       *      type_left       = skip_typeref(orig_type_left);
8211         type_t       *      type_right      = skip_typeref(orig_type_right);
8212
8213         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8214                 /* TODO: improve error message */
8215                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8216                         errorf(&expression->base.source_position,
8217                                "operands of shift operation must have integer types");
8218                 }
8219                 return false;
8220         }
8221
8222         type_left = promote_integer(type_left);
8223
8224         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8225                 long count = fold_constant_to_int(right);
8226                 if (count < 0) {
8227                         warningf(&right->base.source_position,
8228                                         "shift count must be non-negative");
8229                 } else if ((unsigned long)count >=
8230                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8231                         warningf(&right->base.source_position,
8232                                         "shift count must be less than type width");
8233                 }
8234         }
8235
8236         type_right        = promote_integer(type_right);
8237         expression->right = create_implicit_cast(right, type_right);
8238
8239         return true;
8240 }
8241
8242 static void semantic_shift_op(binary_expression_t *expression)
8243 {
8244         expression_t *const left  = expression->left;
8245         expression_t *const right = expression->right;
8246
8247         if (!semantic_shift(expression))
8248                 return;
8249
8250         if (warning.parentheses) {
8251                 warn_addsub_in_shift(left);
8252                 warn_addsub_in_shift(right);
8253         }
8254
8255         type_t *const orig_type_left = left->base.type;
8256         type_t *      type_left      = skip_typeref(orig_type_left);
8257
8258         type_left             = promote_integer(type_left);
8259         expression->left      = create_implicit_cast(left, type_left);
8260         expression->base.type = type_left;
8261 }
8262
8263 static void semantic_add(binary_expression_t *expression)
8264 {
8265         expression_t *const left            = expression->left;
8266         expression_t *const right           = expression->right;
8267         type_t       *const orig_type_left  = left->base.type;
8268         type_t       *const orig_type_right = right->base.type;
8269         type_t       *const type_left       = skip_typeref(orig_type_left);
8270         type_t       *const type_right      = skip_typeref(orig_type_right);
8271
8272         /* §6.5.6 */
8273         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8274                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8275                 expression->left  = create_implicit_cast(left, arithmetic_type);
8276                 expression->right = create_implicit_cast(right, arithmetic_type);
8277                 expression->base.type = arithmetic_type;
8278         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8279                 check_pointer_arithmetic(&expression->base.source_position,
8280                                          type_left, orig_type_left);
8281                 expression->base.type = type_left;
8282         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8283                 check_pointer_arithmetic(&expression->base.source_position,
8284                                          type_right, orig_type_right);
8285                 expression->base.type = type_right;
8286         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8287                 errorf(&expression->base.source_position,
8288                        "invalid operands to binary + ('%T', '%T')",
8289                        orig_type_left, orig_type_right);
8290         }
8291 }
8292
8293 static void semantic_sub(binary_expression_t *expression)
8294 {
8295         expression_t            *const left            = expression->left;
8296         expression_t            *const right           = expression->right;
8297         type_t                  *const orig_type_left  = left->base.type;
8298         type_t                  *const orig_type_right = right->base.type;
8299         type_t                  *const type_left       = skip_typeref(orig_type_left);
8300         type_t                  *const type_right      = skip_typeref(orig_type_right);
8301         source_position_t const *const pos             = &expression->base.source_position;
8302
8303         /* §5.6.5 */
8304         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8305                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8306                 expression->left        = create_implicit_cast(left, arithmetic_type);
8307                 expression->right       = create_implicit_cast(right, arithmetic_type);
8308                 expression->base.type =  arithmetic_type;
8309         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8310                 check_pointer_arithmetic(&expression->base.source_position,
8311                                          type_left, orig_type_left);
8312                 expression->base.type = type_left;
8313         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8314                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8315                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8316                 if (!types_compatible(unqual_left, unqual_right)) {
8317                         errorf(pos,
8318                                "subtracting pointers to incompatible types '%T' and '%T'",
8319                                orig_type_left, orig_type_right);
8320                 } else if (!is_type_object(unqual_left)) {
8321                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8322                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8323                                        orig_type_left);
8324                         } else if (warning.other) {
8325                                 warningf(pos, "subtracting pointers to void");
8326                         }
8327                 }
8328                 expression->base.type = type_ptrdiff_t;
8329         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8330                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8331                        orig_type_left, orig_type_right);
8332         }
8333 }
8334
8335 static void warn_string_literal_address(expression_t const* expr)
8336 {
8337         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8338                 expr = expr->unary.value;
8339                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8340                         return;
8341                 expr = expr->unary.value;
8342         }
8343
8344         if (expr->kind == EXPR_STRING_LITERAL
8345                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8346                 warningf(&expr->base.source_position,
8347                         "comparison with string literal results in unspecified behaviour");
8348         }
8349 }
8350
8351 static bool maybe_negative(expression_t const *const expr)
8352 {
8353         switch (is_constant_expression(expr)) {
8354                 case EXPR_CLASS_ERROR:    return false;
8355                 case EXPR_CLASS_CONSTANT: return fold_constant_to_int(expr) < 0;
8356                 default:                  return true;
8357         }
8358 }
8359
8360 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8361 {
8362         if (warning.address) {
8363                 warn_string_literal_address(expr);
8364
8365                 expression_t const* const ref = get_reference_address(expr);
8366                 if (ref != NULL && is_null_pointer_constant(other)) {
8367                         entity_t const *const ent = ref->reference.entity;
8368                         warningf(pos, "the address of '%N' will never be NULL", ent);
8369                 }
8370         }
8371
8372         if (warning.parentheses && !expr->base.parenthesized) {
8373                 switch (expr->base.kind) {
8374                         case EXPR_BINARY_LESS:
8375                         case EXPR_BINARY_GREATER:
8376                         case EXPR_BINARY_LESSEQUAL:
8377                         case EXPR_BINARY_GREATEREQUAL:
8378                         case EXPR_BINARY_NOTEQUAL:
8379                         case EXPR_BINARY_EQUAL:
8380                                 warningf(pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8381                                 break;
8382                         default:
8383                                 break;
8384                 }
8385         }
8386 }
8387
8388 /**
8389  * Check the semantics of comparison expressions.
8390  *
8391  * @param expression   The expression to check.
8392  */
8393 static void semantic_comparison(binary_expression_t *expression)
8394 {
8395         source_position_t const *const pos   = &expression->base.source_position;
8396         expression_t            *const left  = expression->left;
8397         expression_t            *const right = expression->right;
8398
8399         warn_comparison(pos, left, right);
8400         warn_comparison(pos, right, left);
8401
8402         type_t *orig_type_left  = left->base.type;
8403         type_t *orig_type_right = right->base.type;
8404         type_t *type_left       = skip_typeref(orig_type_left);
8405         type_t *type_right      = skip_typeref(orig_type_right);
8406
8407         /* TODO non-arithmetic types */
8408         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8409                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8410
8411                 /* test for signed vs unsigned compares */
8412                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8413                         bool const signed_left  = is_type_signed(type_left);
8414                         bool const signed_right = is_type_signed(type_right);
8415                         if (signed_left != signed_right) {
8416                                 /* FIXME long long needs better const folding magic */
8417                                 /* TODO check whether constant value can be represented by other type */
8418                                 if ((signed_left  && maybe_negative(left)) ||
8419                                                 (signed_right && maybe_negative(right))) {
8420                                         warningf(pos, "comparison between signed and unsigned");
8421                                 }
8422                         }
8423                 }
8424
8425                 expression->left        = create_implicit_cast(left, arithmetic_type);
8426                 expression->right       = create_implicit_cast(right, arithmetic_type);
8427                 expression->base.type   = arithmetic_type;
8428                 if (warning.float_equal &&
8429                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8430                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8431                     is_type_float(arithmetic_type)) {
8432                         warningf(pos, "comparing floating point with == or != is unsafe");
8433                 }
8434         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8435                 /* TODO check compatibility */
8436         } else if (is_type_pointer(type_left)) {
8437                 expression->right = create_implicit_cast(right, type_left);
8438         } else if (is_type_pointer(type_right)) {
8439                 expression->left = create_implicit_cast(left, type_right);
8440         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8441                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8442         }
8443         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8444 }
8445
8446 /**
8447  * Checks if a compound type has constant fields.
8448  */
8449 static bool has_const_fields(const compound_type_t *type)
8450 {
8451         compound_t *compound = type->compound;
8452         entity_t   *entry    = compound->members.entities;
8453
8454         for (; entry != NULL; entry = entry->base.next) {
8455                 if (!is_declaration(entry))
8456                         continue;
8457
8458                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8459                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8460                         return true;
8461         }
8462
8463         return false;
8464 }
8465
8466 static bool is_valid_assignment_lhs(expression_t const* const left)
8467 {
8468         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8469         type_t *const type_left      = skip_typeref(orig_type_left);
8470
8471         if (!is_lvalue(left)) {
8472                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8473                        left);
8474                 return false;
8475         }
8476
8477         if (left->kind == EXPR_REFERENCE
8478                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8479                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8480                 return false;
8481         }
8482
8483         if (is_type_array(type_left)) {
8484                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8485                 return false;
8486         }
8487         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8488                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8489                        orig_type_left);
8490                 return false;
8491         }
8492         if (is_type_incomplete(type_left)) {
8493                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8494                        left, orig_type_left);
8495                 return false;
8496         }
8497         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8498                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8499                        left, orig_type_left);
8500                 return false;
8501         }
8502
8503         return true;
8504 }
8505
8506 static void semantic_arithmetic_assign(binary_expression_t *expression)
8507 {
8508         expression_t *left            = expression->left;
8509         expression_t *right           = expression->right;
8510         type_t       *orig_type_left  = left->base.type;
8511         type_t       *orig_type_right = right->base.type;
8512
8513         if (!is_valid_assignment_lhs(left))
8514                 return;
8515
8516         type_t *type_left  = skip_typeref(orig_type_left);
8517         type_t *type_right = skip_typeref(orig_type_right);
8518
8519         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8520                 /* TODO: improve error message */
8521                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8522                         errorf(&expression->base.source_position,
8523                                "operation needs arithmetic types");
8524                 }
8525                 return;
8526         }
8527
8528         /* combined instructions are tricky. We can't create an implicit cast on
8529          * the left side, because we need the uncasted form for the store.
8530          * The ast2firm pass has to know that left_type must be right_type
8531          * for the arithmetic operation and create a cast by itself */
8532         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8533         expression->right       = create_implicit_cast(right, arithmetic_type);
8534         expression->base.type   = type_left;
8535 }
8536
8537 static void semantic_divmod_assign(binary_expression_t *expression)
8538 {
8539         semantic_arithmetic_assign(expression);
8540         warn_div_by_zero(expression);
8541 }
8542
8543 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8544 {
8545         expression_t *const left            = expression->left;
8546         expression_t *const right           = expression->right;
8547         type_t       *const orig_type_left  = left->base.type;
8548         type_t       *const orig_type_right = right->base.type;
8549         type_t       *const type_left       = skip_typeref(orig_type_left);
8550         type_t       *const type_right      = skip_typeref(orig_type_right);
8551
8552         if (!is_valid_assignment_lhs(left))
8553                 return;
8554
8555         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8556                 /* combined instructions are tricky. We can't create an implicit cast on
8557                  * the left side, because we need the uncasted form for the store.
8558                  * The ast2firm pass has to know that left_type must be right_type
8559                  * for the arithmetic operation and create a cast by itself */
8560                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8561                 expression->right     = create_implicit_cast(right, arithmetic_type);
8562                 expression->base.type = type_left;
8563         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8564                 check_pointer_arithmetic(&expression->base.source_position,
8565                                          type_left, orig_type_left);
8566                 expression->base.type = type_left;
8567         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8568                 errorf(&expression->base.source_position,
8569                        "incompatible types '%T' and '%T' in assignment",
8570                        orig_type_left, orig_type_right);
8571         }
8572 }
8573
8574 static void semantic_integer_assign(binary_expression_t *expression)
8575 {
8576         expression_t *left            = expression->left;
8577         expression_t *right           = expression->right;
8578         type_t       *orig_type_left  = left->base.type;
8579         type_t       *orig_type_right = right->base.type;
8580
8581         if (!is_valid_assignment_lhs(left))
8582                 return;
8583
8584         type_t *type_left  = skip_typeref(orig_type_left);
8585         type_t *type_right = skip_typeref(orig_type_right);
8586
8587         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8588                 /* TODO: improve error message */
8589                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8590                         errorf(&expression->base.source_position,
8591                                "operation needs integer types");
8592                 }
8593                 return;
8594         }
8595
8596         /* combined instructions are tricky. We can't create an implicit cast on
8597          * the left side, because we need the uncasted form for the store.
8598          * The ast2firm pass has to know that left_type must be right_type
8599          * for the arithmetic operation and create a cast by itself */
8600         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8601         expression->right       = create_implicit_cast(right, arithmetic_type);
8602         expression->base.type   = type_left;
8603 }
8604
8605 static void semantic_shift_assign(binary_expression_t *expression)
8606 {
8607         expression_t *left           = expression->left;
8608
8609         if (!is_valid_assignment_lhs(left))
8610                 return;
8611
8612         if (!semantic_shift(expression))
8613                 return;
8614
8615         expression->base.type = skip_typeref(left->base.type);
8616 }
8617
8618 static void warn_logical_and_within_or(const expression_t *const expr)
8619 {
8620         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8621                 return;
8622         if (expr->base.parenthesized)
8623                 return;
8624         warningf(&expr->base.source_position,
8625                         "suggest parentheses around && within ||");
8626 }
8627
8628 /**
8629  * Check the semantic restrictions of a logical expression.
8630  */
8631 static void semantic_logical_op(binary_expression_t *expression)
8632 {
8633         /* §6.5.13:2  Each of the operands shall have scalar type.
8634          * §6.5.14:2  Each of the operands shall have scalar type. */
8635         semantic_condition(expression->left,   "left operand of logical operator");
8636         semantic_condition(expression->right, "right operand of logical operator");
8637         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8638                         warning.parentheses) {
8639                 warn_logical_and_within_or(expression->left);
8640                 warn_logical_and_within_or(expression->right);
8641         }
8642         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8643 }
8644
8645 /**
8646  * Check the semantic restrictions of a binary assign expression.
8647  */
8648 static void semantic_binexpr_assign(binary_expression_t *expression)
8649 {
8650         expression_t *left           = expression->left;
8651         type_t       *orig_type_left = left->base.type;
8652
8653         if (!is_valid_assignment_lhs(left))
8654                 return;
8655
8656         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8657         report_assign_error(error, orig_type_left, expression->right,
8658                         "assignment", &left->base.source_position);
8659         expression->right = create_implicit_cast(expression->right, orig_type_left);
8660         expression->base.type = orig_type_left;
8661 }
8662
8663 /**
8664  * Determine if the outermost operation (or parts thereof) of the given
8665  * expression has no effect in order to generate a warning about this fact.
8666  * Therefore in some cases this only examines some of the operands of the
8667  * expression (see comments in the function and examples below).
8668  * Examples:
8669  *   f() + 23;    // warning, because + has no effect
8670  *   x || f();    // no warning, because x controls execution of f()
8671  *   x ? y : f(); // warning, because y has no effect
8672  *   (void)x;     // no warning to be able to suppress the warning
8673  * This function can NOT be used for an "expression has definitely no effect"-
8674  * analysis. */
8675 static bool expression_has_effect(const expression_t *const expr)
8676 {
8677         switch (expr->kind) {
8678                 case EXPR_UNKNOWN:                    break;
8679                 case EXPR_INVALID:                    return true; /* do NOT warn */
8680                 case EXPR_REFERENCE:                  return false;
8681                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8682                 case EXPR_LABEL_ADDRESS:              return false;
8683
8684                 /* suppress the warning for microsoft __noop operations */
8685                 case EXPR_LITERAL_MS_NOOP:            return true;
8686                 case EXPR_LITERAL_BOOLEAN:
8687                 case EXPR_LITERAL_CHARACTER:
8688                 case EXPR_LITERAL_WIDE_CHARACTER:
8689                 case EXPR_LITERAL_INTEGER:
8690                 case EXPR_LITERAL_INTEGER_OCTAL:
8691                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8692                 case EXPR_LITERAL_FLOATINGPOINT:
8693                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8694                 case EXPR_STRING_LITERAL:             return false;
8695                 case EXPR_WIDE_STRING_LITERAL:        return false;
8696
8697                 case EXPR_CALL: {
8698                         const call_expression_t *const call = &expr->call;
8699                         if (call->function->kind != EXPR_REFERENCE)
8700                                 return true;
8701
8702                         switch (call->function->reference.entity->function.btk) {
8703                                 /* FIXME: which builtins have no effect? */
8704                                 default:                      return true;
8705                         }
8706                 }
8707
8708                 /* Generate the warning if either the left or right hand side of a
8709                  * conditional expression has no effect */
8710                 case EXPR_CONDITIONAL: {
8711                         conditional_expression_t const *const cond = &expr->conditional;
8712                         expression_t             const *const t    = cond->true_expression;
8713                         return
8714                                 (t == NULL || expression_has_effect(t)) &&
8715                                 expression_has_effect(cond->false_expression);
8716                 }
8717
8718                 case EXPR_SELECT:                     return false;
8719                 case EXPR_ARRAY_ACCESS:               return false;
8720                 case EXPR_SIZEOF:                     return false;
8721                 case EXPR_CLASSIFY_TYPE:              return false;
8722                 case EXPR_ALIGNOF:                    return false;
8723
8724                 case EXPR_FUNCNAME:                   return false;
8725                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8726                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8727                 case EXPR_OFFSETOF:                   return false;
8728                 case EXPR_VA_START:                   return true;
8729                 case EXPR_VA_ARG:                     return true;
8730                 case EXPR_VA_COPY:                    return true;
8731                 case EXPR_STATEMENT:                  return true; // TODO
8732                 case EXPR_COMPOUND_LITERAL:           return false;
8733
8734                 case EXPR_UNARY_NEGATE:               return false;
8735                 case EXPR_UNARY_PLUS:                 return false;
8736                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8737                 case EXPR_UNARY_NOT:                  return false;
8738                 case EXPR_UNARY_DEREFERENCE:          return false;
8739                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8740                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8741                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8742                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8743                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8744
8745                 /* Treat void casts as if they have an effect in order to being able to
8746                  * suppress the warning */
8747                 case EXPR_UNARY_CAST: {
8748                         type_t *const type = skip_typeref(expr->base.type);
8749                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8750                 }
8751
8752                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8753                 case EXPR_UNARY_ASSUME:               return true;
8754                 case EXPR_UNARY_DELETE:               return true;
8755                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8756                 case EXPR_UNARY_THROW:                return true;
8757
8758                 case EXPR_BINARY_ADD:                 return false;
8759                 case EXPR_BINARY_SUB:                 return false;
8760                 case EXPR_BINARY_MUL:                 return false;
8761                 case EXPR_BINARY_DIV:                 return false;
8762                 case EXPR_BINARY_MOD:                 return false;
8763                 case EXPR_BINARY_EQUAL:               return false;
8764                 case EXPR_BINARY_NOTEQUAL:            return false;
8765                 case EXPR_BINARY_LESS:                return false;
8766                 case EXPR_BINARY_LESSEQUAL:           return false;
8767                 case EXPR_BINARY_GREATER:             return false;
8768                 case EXPR_BINARY_GREATEREQUAL:        return false;
8769                 case EXPR_BINARY_BITWISE_AND:         return false;
8770                 case EXPR_BINARY_BITWISE_OR:          return false;
8771                 case EXPR_BINARY_BITWISE_XOR:         return false;
8772                 case EXPR_BINARY_SHIFTLEFT:           return false;
8773                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8774                 case EXPR_BINARY_ASSIGN:              return true;
8775                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8776                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8777                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8778                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8779                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8780                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8781                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8782                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8783                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8784                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8785
8786                 /* Only examine the right hand side of && and ||, because the left hand
8787                  * side already has the effect of controlling the execution of the right
8788                  * hand side */
8789                 case EXPR_BINARY_LOGICAL_AND:
8790                 case EXPR_BINARY_LOGICAL_OR:
8791                 /* Only examine the right hand side of a comma expression, because the left
8792                  * hand side has a separate warning */
8793                 case EXPR_BINARY_COMMA:
8794                         return expression_has_effect(expr->binary.right);
8795
8796                 case EXPR_BINARY_ISGREATER:           return false;
8797                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8798                 case EXPR_BINARY_ISLESS:              return false;
8799                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8800                 case EXPR_BINARY_ISLESSGREATER:       return false;
8801                 case EXPR_BINARY_ISUNORDERED:         return false;
8802         }
8803
8804         internal_errorf(HERE, "unexpected expression");
8805 }
8806
8807 static void semantic_comma(binary_expression_t *expression)
8808 {
8809         if (warning.unused_value) {
8810                 const expression_t *const left = expression->left;
8811                 if (!expression_has_effect(left)) {
8812                         warningf(&left->base.source_position,
8813                                  "left-hand operand of comma expression has no effect");
8814                 }
8815         }
8816         expression->base.type = expression->right->base.type;
8817 }
8818
8819 /**
8820  * @param prec_r precedence of the right operand
8821  */
8822 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8823 static expression_t *parse_##binexpression_type(expression_t *left)          \
8824 {                                                                            \
8825         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8826         binexpr->binary.left  = left;                                            \
8827         eat(token_type);                                                         \
8828                                                                              \
8829         expression_t *right = parse_subexpression(prec_r);                       \
8830                                                                              \
8831         binexpr->binary.right = right;                                           \
8832         sfunc(&binexpr->binary);                                                 \
8833                                                                              \
8834         return binexpr;                                                          \
8835 }
8836
8837 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8838 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8839 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8840 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8841 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8842 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8843 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8844 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8845 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8846 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8847 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8848 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8849 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8850 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8851 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8852 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8853 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8854 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8855 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8856 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8857 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8858 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8859 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8860 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8861 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8862 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8863 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8864 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8865 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8866 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8867
8868
8869 static expression_t *parse_subexpression(precedence_t precedence)
8870 {
8871         if (token.type < 0) {
8872                 return expected_expression_error();
8873         }
8874
8875         expression_parser_function_t *parser
8876                 = &expression_parsers[token.type];
8877         source_position_t             source_position = token.source_position;
8878         expression_t                 *left;
8879
8880         if (parser->parser != NULL) {
8881                 left = parser->parser();
8882         } else {
8883                 left = parse_primary_expression();
8884         }
8885         assert(left != NULL);
8886         left->base.source_position = source_position;
8887
8888         while (true) {
8889                 if (token.type < 0) {
8890                         return expected_expression_error();
8891                 }
8892
8893                 parser = &expression_parsers[token.type];
8894                 if (parser->infix_parser == NULL)
8895                         break;
8896                 if (parser->infix_precedence < precedence)
8897                         break;
8898
8899                 left = parser->infix_parser(left);
8900
8901                 assert(left != NULL);
8902                 assert(left->kind != EXPR_UNKNOWN);
8903                 left->base.source_position = source_position;
8904         }
8905
8906         return left;
8907 }
8908
8909 /**
8910  * Parse an expression.
8911  */
8912 static expression_t *parse_expression(void)
8913 {
8914         return parse_subexpression(PREC_EXPRESSION);
8915 }
8916
8917 /**
8918  * Register a parser for a prefix-like operator.
8919  *
8920  * @param parser      the parser function
8921  * @param token_type  the token type of the prefix token
8922  */
8923 static void register_expression_parser(parse_expression_function parser,
8924                                        int token_type)
8925 {
8926         expression_parser_function_t *entry = &expression_parsers[token_type];
8927
8928         if (entry->parser != NULL) {
8929                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
8930                 panic("trying to register multiple expression parsers for a token");
8931         }
8932         entry->parser = parser;
8933 }
8934
8935 /**
8936  * Register a parser for an infix operator with given precedence.
8937  *
8938  * @param parser      the parser function
8939  * @param token_type  the token type of the infix operator
8940  * @param precedence  the precedence of the operator
8941  */
8942 static void register_infix_parser(parse_expression_infix_function parser,
8943                                   int token_type, precedence_t precedence)
8944 {
8945         expression_parser_function_t *entry = &expression_parsers[token_type];
8946
8947         if (entry->infix_parser != NULL) {
8948                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
8949                 panic("trying to register multiple infix expression parsers for a "
8950                       "token");
8951         }
8952         entry->infix_parser     = parser;
8953         entry->infix_precedence = precedence;
8954 }
8955
8956 /**
8957  * Initialize the expression parsers.
8958  */
8959 static void init_expression_parsers(void)
8960 {
8961         memset(&expression_parsers, 0, sizeof(expression_parsers));
8962
8963         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8964         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8965         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8966         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8967         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8968         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8969         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8970         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8971         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8972         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8973         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8974         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8975         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8976         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8977         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8978         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8979         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8980         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8981         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8982         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8983         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8984         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8985         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8986         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8987         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8988         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8989         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8990         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8991         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8992         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8993         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8994         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8995         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8996         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8997         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8998         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8999         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9000
9001         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9002         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9003         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9004         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9005         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9006         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9007         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9008         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9009         register_expression_parser(parse_sizeof,                      T_sizeof);
9010         register_expression_parser(parse_alignof,                     T___alignof__);
9011         register_expression_parser(parse_extension,                   T___extension__);
9012         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9013         register_expression_parser(parse_delete,                      T_delete);
9014         register_expression_parser(parse_throw,                       T_throw);
9015 }
9016
9017 /**
9018  * Parse a asm statement arguments specification.
9019  */
9020 static asm_argument_t *parse_asm_arguments(bool is_out)
9021 {
9022         asm_argument_t  *result = NULL;
9023         asm_argument_t **anchor = &result;
9024
9025         while (token.type == T_STRING_LITERAL || token.type == '[') {
9026                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9027                 memset(argument, 0, sizeof(argument[0]));
9028
9029                 if (next_if('[')) {
9030                         if (token.type != T_IDENTIFIER) {
9031                                 parse_error_expected("while parsing asm argument",
9032                                                      T_IDENTIFIER, NULL);
9033                                 return NULL;
9034                         }
9035                         argument->symbol = token.symbol;
9036
9037                         expect(']', end_error);
9038                 }
9039
9040                 argument->constraints = parse_string_literals();
9041                 expect('(', end_error);
9042                 add_anchor_token(')');
9043                 expression_t *expression = parse_expression();
9044                 rem_anchor_token(')');
9045                 if (is_out) {
9046                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9047                          * change size or type representation (e.g. int -> long is ok, but
9048                          * int -> float is not) */
9049                         if (expression->kind == EXPR_UNARY_CAST) {
9050                                 type_t      *const type = expression->base.type;
9051                                 type_kind_t  const kind = type->kind;
9052                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9053                                         unsigned flags;
9054                                         unsigned size;
9055                                         if (kind == TYPE_ATOMIC) {
9056                                                 atomic_type_kind_t const akind = type->atomic.akind;
9057                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9058                                                 size  = get_atomic_type_size(akind);
9059                                         } else {
9060                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9061                                                 size  = get_atomic_type_size(get_intptr_kind());
9062                                         }
9063
9064                                         do {
9065                                                 expression_t *const value      = expression->unary.value;
9066                                                 type_t       *const value_type = value->base.type;
9067                                                 type_kind_t   const value_kind = value_type->kind;
9068
9069                                                 unsigned value_flags;
9070                                                 unsigned value_size;
9071                                                 if (value_kind == TYPE_ATOMIC) {
9072                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9073                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9074                                                         value_size  = get_atomic_type_size(value_akind);
9075                                                 } else if (value_kind == TYPE_POINTER) {
9076                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9077                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9078                                                 } else {
9079                                                         break;
9080                                                 }
9081
9082                                                 if (value_flags != flags || value_size != size)
9083                                                         break;
9084
9085                                                 expression = value;
9086                                         } while (expression->kind == EXPR_UNARY_CAST);
9087                                 }
9088                         }
9089
9090                         if (!is_lvalue(expression)) {
9091                                 errorf(&expression->base.source_position,
9092                                        "asm output argument is not an lvalue");
9093                         }
9094
9095                         if (argument->constraints.begin[0] == '=')
9096                                 determine_lhs_ent(expression, NULL);
9097                         else
9098                                 mark_vars_read(expression, NULL);
9099                 } else {
9100                         mark_vars_read(expression, NULL);
9101                 }
9102                 argument->expression = expression;
9103                 expect(')', end_error);
9104
9105                 set_address_taken(expression, true);
9106
9107                 *anchor = argument;
9108                 anchor  = &argument->next;
9109
9110                 if (!next_if(','))
9111                         break;
9112         }
9113
9114         return result;
9115 end_error:
9116         return NULL;
9117 }
9118
9119 /**
9120  * Parse a asm statement clobber specification.
9121  */
9122 static asm_clobber_t *parse_asm_clobbers(void)
9123 {
9124         asm_clobber_t *result  = NULL;
9125         asm_clobber_t **anchor = &result;
9126
9127         while (token.type == T_STRING_LITERAL) {
9128                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9129                 clobber->clobber       = parse_string_literals();
9130
9131                 *anchor = clobber;
9132                 anchor  = &clobber->next;
9133
9134                 if (!next_if(','))
9135                         break;
9136         }
9137
9138         return result;
9139 }
9140
9141 /**
9142  * Parse an asm statement.
9143  */
9144 static statement_t *parse_asm_statement(void)
9145 {
9146         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9147         asm_statement_t *asm_statement = &statement->asms;
9148
9149         eat(T_asm);
9150
9151         if (next_if(T_volatile))
9152                 asm_statement->is_volatile = true;
9153
9154         expect('(', end_error);
9155         add_anchor_token(')');
9156         if (token.type != T_STRING_LITERAL) {
9157                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
9158                 goto end_of_asm;
9159         }
9160         asm_statement->asm_text = parse_string_literals();
9161
9162         add_anchor_token(':');
9163         if (!next_if(':')) {
9164                 rem_anchor_token(':');
9165                 goto end_of_asm;
9166         }
9167
9168         asm_statement->outputs = parse_asm_arguments(true);
9169         if (!next_if(':')) {
9170                 rem_anchor_token(':');
9171                 goto end_of_asm;
9172         }
9173
9174         asm_statement->inputs = parse_asm_arguments(false);
9175         if (!next_if(':')) {
9176                 rem_anchor_token(':');
9177                 goto end_of_asm;
9178         }
9179         rem_anchor_token(':');
9180
9181         asm_statement->clobbers = parse_asm_clobbers();
9182
9183 end_of_asm:
9184         rem_anchor_token(')');
9185         expect(')', end_error);
9186         expect(';', end_error);
9187
9188         if (asm_statement->outputs == NULL) {
9189                 /* GCC: An 'asm' instruction without any output operands will be treated
9190                  * identically to a volatile 'asm' instruction. */
9191                 asm_statement->is_volatile = true;
9192         }
9193
9194         return statement;
9195 end_error:
9196         return create_invalid_statement();
9197 }
9198
9199 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9200 {
9201         statement_t *inner_stmt;
9202         switch (token.type) {
9203                 case '}':
9204                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9205                         inner_stmt = create_invalid_statement();
9206                         break;
9207
9208                 case ';':
9209                         if (label->kind == STATEMENT_LABEL) {
9210                                 /* Eat an empty statement here, to avoid the warning about an empty
9211                                  * statement after a label.  label:; is commonly used to have a label
9212                                  * before a closing brace. */
9213                                 inner_stmt = create_empty_statement();
9214                                 next_token();
9215                                 break;
9216                         }
9217                         /* FALLTHROUGH */
9218
9219                 default:
9220                         inner_stmt = parse_statement();
9221                         /* ISO/IEC 14882:1998(E) §6:1/§6.7  Declarations are statements */
9222                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9223                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9224                         }
9225                         break;
9226         }
9227         return inner_stmt;
9228 }
9229
9230 /**
9231  * Parse a case statement.
9232  */
9233 static statement_t *parse_case_statement(void)
9234 {
9235         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9236         source_position_t *const pos       = &statement->base.source_position;
9237
9238         eat(T_case);
9239
9240         expression_t *const expression   = parse_expression();
9241         statement->case_label.expression = expression;
9242         expression_classification_t const expr_class = is_constant_expression(expression);
9243         if (expr_class != EXPR_CLASS_CONSTANT) {
9244                 if (expr_class != EXPR_CLASS_ERROR) {
9245                         errorf(pos, "case label does not reduce to an integer constant");
9246                 }
9247                 statement->case_label.is_bad = true;
9248         } else {
9249                 long const val = fold_constant_to_int(expression);
9250                 statement->case_label.first_case = val;
9251                 statement->case_label.last_case  = val;
9252         }
9253
9254         if (GNU_MODE) {
9255                 if (next_if(T_DOTDOTDOT)) {
9256                         expression_t *const end_range   = parse_expression();
9257                         statement->case_label.end_range = end_range;
9258                         expression_classification_t const end_class = is_constant_expression(end_range);
9259                         if (end_class != EXPR_CLASS_CONSTANT) {
9260                                 if (end_class != EXPR_CLASS_ERROR) {
9261                                         errorf(pos, "case range does not reduce to an integer constant");
9262                                 }
9263                                 statement->case_label.is_bad = true;
9264                         } else {
9265                                 long const val = fold_constant_to_int(end_range);
9266                                 statement->case_label.last_case = val;
9267
9268                                 if (warning.other && val < statement->case_label.first_case) {
9269                                         statement->case_label.is_empty_range = true;
9270                                         warningf(pos, "empty range specified");
9271                                 }
9272                         }
9273                 }
9274         }
9275
9276         PUSH_PARENT(statement);
9277
9278         expect(':', end_error);
9279 end_error:
9280
9281         if (current_switch != NULL) {
9282                 if (! statement->case_label.is_bad) {
9283                         /* Check for duplicate case values */
9284                         case_label_statement_t *c = &statement->case_label;
9285                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9286                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9287                                         continue;
9288
9289                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9290                                         continue;
9291
9292                                 errorf(pos, "duplicate case value (previously used %P)",
9293                                        &l->base.source_position);
9294                                 break;
9295                         }
9296                 }
9297                 /* link all cases into the switch statement */
9298                 if (current_switch->last_case == NULL) {
9299                         current_switch->first_case      = &statement->case_label;
9300                 } else {
9301                         current_switch->last_case->next = &statement->case_label;
9302                 }
9303                 current_switch->last_case = &statement->case_label;
9304         } else {
9305                 errorf(pos, "case label not within a switch statement");
9306         }
9307
9308         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9309
9310         POP_PARENT;
9311         return statement;
9312 }
9313
9314 /**
9315  * Parse a default statement.
9316  */
9317 static statement_t *parse_default_statement(void)
9318 {
9319         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9320
9321         eat(T_default);
9322
9323         PUSH_PARENT(statement);
9324
9325         expect(':', end_error);
9326 end_error:
9327
9328         if (current_switch != NULL) {
9329                 const case_label_statement_t *def_label = current_switch->default_label;
9330                 if (def_label != NULL) {
9331                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9332                 } else {
9333                         current_switch->default_label = &statement->case_label;
9334
9335                         /* link all cases into the switch statement */
9336                         if (current_switch->last_case == NULL) {
9337                                 current_switch->first_case      = &statement->case_label;
9338                         } else {
9339                                 current_switch->last_case->next = &statement->case_label;
9340                         }
9341                         current_switch->last_case = &statement->case_label;
9342                 }
9343         } else {
9344                 errorf(&statement->base.source_position,
9345                         "'default' label not within a switch statement");
9346         }
9347
9348         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9349
9350         POP_PARENT;
9351         return statement;
9352 }
9353
9354 /**
9355  * Parse a label statement.
9356  */
9357 static statement_t *parse_label_statement(void)
9358 {
9359         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9360         label_t     *const label     = get_label();
9361         statement->label.label = label;
9362
9363         PUSH_PARENT(statement);
9364
9365         /* if statement is already set then the label is defined twice,
9366          * otherwise it was just mentioned in a goto/local label declaration so far
9367          */
9368         source_position_t const* const pos = &statement->base.source_position;
9369         if (label->statement != NULL) {
9370                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9371         } else {
9372                 label->base.source_position = *pos;
9373                 label->statement            = statement;
9374         }
9375
9376         eat(':');
9377
9378         statement->label.statement = parse_label_inner_statement(statement, "label");
9379
9380         /* remember the labels in a list for later checking */
9381         *label_anchor = &statement->label;
9382         label_anchor  = &statement->label.next;
9383
9384         POP_PARENT;
9385         return statement;
9386 }
9387
9388 /**
9389  * Parse an if statement.
9390  */
9391 static statement_t *parse_if(void)
9392 {
9393         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9394
9395         eat(T_if);
9396
9397         PUSH_PARENT(statement);
9398
9399         add_anchor_token('{');
9400
9401         expect('(', end_error);
9402         add_anchor_token(')');
9403         expression_t *const expr = parse_expression();
9404         statement->ifs.condition = expr;
9405         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9406          *             scalar type. */
9407         semantic_condition(expr, "condition of 'if'-statment");
9408         mark_vars_read(expr, NULL);
9409         rem_anchor_token(')');
9410         expect(')', end_error);
9411
9412 end_error:
9413         rem_anchor_token('{');
9414
9415         add_anchor_token(T_else);
9416         statement_t *const true_stmt = parse_statement();
9417         statement->ifs.true_statement = true_stmt;
9418         rem_anchor_token(T_else);
9419
9420         if (next_if(T_else)) {
9421                 statement->ifs.false_statement = parse_statement();
9422         } else if (warning.parentheses &&
9423                         true_stmt->kind == STATEMENT_IF &&
9424                         true_stmt->ifs.false_statement != NULL) {
9425                 warningf(&true_stmt->base.source_position,
9426                                 "suggest explicit braces to avoid ambiguous 'else'");
9427         }
9428
9429         POP_PARENT;
9430         return statement;
9431 }
9432
9433 /**
9434  * Check that all enums are handled in a switch.
9435  *
9436  * @param statement  the switch statement to check
9437  */
9438 static void check_enum_cases(const switch_statement_t *statement)
9439 {
9440         const type_t *type = skip_typeref(statement->expression->base.type);
9441         if (! is_type_enum(type))
9442                 return;
9443         const enum_type_t *enumt = &type->enumt;
9444
9445         /* if we have a default, no warnings */
9446         if (statement->default_label != NULL)
9447                 return;
9448
9449         /* FIXME: calculation of value should be done while parsing */
9450         /* TODO: quadratic algorithm here. Change to an n log n one */
9451         long            last_value = -1;
9452         const entity_t *entry      = enumt->enume->base.next;
9453         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9454              entry = entry->base.next) {
9455                 const expression_t *expression = entry->enum_value.value;
9456                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9457                 bool                found      = false;
9458                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9459                         if (l->expression == NULL)
9460                                 continue;
9461                         if (l->first_case <= value && value <= l->last_case) {
9462                                 found = true;
9463                                 break;
9464                         }
9465                 }
9466                 if (!found) {
9467                         warningf(&statement->base.source_position, "'%N' not handled in switch", entry);
9468                 }
9469                 last_value = value;
9470         }
9471 }
9472
9473 /**
9474  * Parse a switch statement.
9475  */
9476 static statement_t *parse_switch(void)
9477 {
9478         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9479
9480         eat(T_switch);
9481
9482         PUSH_PARENT(statement);
9483
9484         expect('(', end_error);
9485         add_anchor_token(')');
9486         expression_t *const expr = parse_expression();
9487         mark_vars_read(expr, NULL);
9488         type_t       *      type = skip_typeref(expr->base.type);
9489         if (is_type_integer(type)) {
9490                 type = promote_integer(type);
9491                 if (warning.traditional) {
9492                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9493                                 warningf(&expr->base.source_position,
9494                                         "'%T' switch expression not converted to '%T' in ISO C",
9495                                         type, type_int);
9496                         }
9497                 }
9498         } else if (is_type_valid(type)) {
9499                 errorf(&expr->base.source_position,
9500                        "switch quantity is not an integer, but '%T'", type);
9501                 type = type_error_type;
9502         }
9503         statement->switchs.expression = create_implicit_cast(expr, type);
9504         expect(')', end_error);
9505         rem_anchor_token(')');
9506
9507         switch_statement_t *rem = current_switch;
9508         current_switch          = &statement->switchs;
9509         statement->switchs.body = parse_statement();
9510         current_switch          = rem;
9511
9512         if (warning.switch_default &&
9513             statement->switchs.default_label == NULL) {
9514                 warningf(&statement->base.source_position, "switch has no default case");
9515         }
9516         if (warning.switch_enum)
9517                 check_enum_cases(&statement->switchs);
9518
9519         POP_PARENT;
9520         return statement;
9521 end_error:
9522         POP_PARENT;
9523         return create_invalid_statement();
9524 }
9525
9526 static statement_t *parse_loop_body(statement_t *const loop)
9527 {
9528         statement_t *const rem = current_loop;
9529         current_loop = loop;
9530
9531         statement_t *const body = parse_statement();
9532
9533         current_loop = rem;
9534         return body;
9535 }
9536
9537 /**
9538  * Parse a while statement.
9539  */
9540 static statement_t *parse_while(void)
9541 {
9542         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9543
9544         eat(T_while);
9545
9546         PUSH_PARENT(statement);
9547
9548         expect('(', end_error);
9549         add_anchor_token(')');
9550         expression_t *const cond = parse_expression();
9551         statement->whiles.condition = cond;
9552         /* §6.8.5:2    The controlling expression of an iteration statement shall
9553          *             have scalar type. */
9554         semantic_condition(cond, "condition of 'while'-statement");
9555         mark_vars_read(cond, NULL);
9556         rem_anchor_token(')');
9557         expect(')', end_error);
9558
9559         statement->whiles.body = parse_loop_body(statement);
9560
9561         POP_PARENT;
9562         return statement;
9563 end_error:
9564         POP_PARENT;
9565         return create_invalid_statement();
9566 }
9567
9568 /**
9569  * Parse a do statement.
9570  */
9571 static statement_t *parse_do(void)
9572 {
9573         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9574
9575         eat(T_do);
9576
9577         PUSH_PARENT(statement);
9578
9579         add_anchor_token(T_while);
9580         statement->do_while.body = parse_loop_body(statement);
9581         rem_anchor_token(T_while);
9582
9583         expect(T_while, end_error);
9584         expect('(', end_error);
9585         add_anchor_token(')');
9586         expression_t *const cond = parse_expression();
9587         statement->do_while.condition = cond;
9588         /* §6.8.5:2    The controlling expression of an iteration statement shall
9589          *             have scalar type. */
9590         semantic_condition(cond, "condition of 'do-while'-statement");
9591         mark_vars_read(cond, NULL);
9592         rem_anchor_token(')');
9593         expect(')', end_error);
9594         expect(';', end_error);
9595
9596         POP_PARENT;
9597         return statement;
9598 end_error:
9599         POP_PARENT;
9600         return create_invalid_statement();
9601 }
9602
9603 /**
9604  * Parse a for statement.
9605  */
9606 static statement_t *parse_for(void)
9607 {
9608         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9609
9610         eat(T_for);
9611
9612         expect('(', end_error1);
9613         add_anchor_token(')');
9614
9615         PUSH_PARENT(statement);
9616
9617         size_t const  top       = environment_top();
9618         scope_t      *old_scope = scope_push(&statement->fors.scope);
9619
9620         bool old_gcc_extension = in_gcc_extension;
9621         while (next_if(T___extension__)) {
9622                 in_gcc_extension = true;
9623         }
9624
9625         if (next_if(';')) {
9626         } else if (is_declaration_specifier(&token)) {
9627                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9628         } else {
9629                 add_anchor_token(';');
9630                 expression_t *const init = parse_expression();
9631                 statement->fors.initialisation = init;
9632                 mark_vars_read(init, ENT_ANY);
9633                 if (warning.unused_value && !expression_has_effect(init)) {
9634                         warningf(&init->base.source_position,
9635                                         "initialisation of 'for'-statement has no effect");
9636                 }
9637                 rem_anchor_token(';');
9638                 expect(';', end_error2);
9639         }
9640         in_gcc_extension = old_gcc_extension;
9641
9642         if (token.type != ';') {
9643                 add_anchor_token(';');
9644                 expression_t *const cond = parse_expression();
9645                 statement->fors.condition = cond;
9646                 /* §6.8.5:2    The controlling expression of an iteration statement
9647                  *             shall have scalar type. */
9648                 semantic_condition(cond, "condition of 'for'-statement");
9649                 mark_vars_read(cond, NULL);
9650                 rem_anchor_token(';');
9651         }
9652         expect(';', end_error2);
9653         if (token.type != ')') {
9654                 expression_t *const step = parse_expression();
9655                 statement->fors.step = step;
9656                 mark_vars_read(step, ENT_ANY);
9657                 if (warning.unused_value && !expression_has_effect(step)) {
9658                         warningf(&step->base.source_position,
9659                                  "step of 'for'-statement has no effect");
9660                 }
9661         }
9662         expect(')', end_error2);
9663         rem_anchor_token(')');
9664         statement->fors.body = parse_loop_body(statement);
9665
9666         assert(current_scope == &statement->fors.scope);
9667         scope_pop(old_scope);
9668         environment_pop_to(top);
9669
9670         POP_PARENT;
9671         return statement;
9672
9673 end_error2:
9674         POP_PARENT;
9675         rem_anchor_token(')');
9676         assert(current_scope == &statement->fors.scope);
9677         scope_pop(old_scope);
9678         environment_pop_to(top);
9679         /* fallthrough */
9680
9681 end_error1:
9682         return create_invalid_statement();
9683 }
9684
9685 /**
9686  * Parse a goto statement.
9687  */
9688 static statement_t *parse_goto(void)
9689 {
9690         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9691         eat(T_goto);
9692
9693         if (GNU_MODE && next_if('*')) {
9694                 expression_t *expression = parse_expression();
9695                 mark_vars_read(expression, NULL);
9696
9697                 /* Argh: although documentation says the expression must be of type void*,
9698                  * gcc accepts anything that can be casted into void* without error */
9699                 type_t *type = expression->base.type;
9700
9701                 if (type != type_error_type) {
9702                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9703                                 errorf(&expression->base.source_position,
9704                                         "cannot convert to a pointer type");
9705                         } else if (warning.other && type != type_void_ptr) {
9706                                 warningf(&expression->base.source_position,
9707                                         "type of computed goto expression should be 'void*' not '%T'", type);
9708                         }
9709                         expression = create_implicit_cast(expression, type_void_ptr);
9710                 }
9711
9712                 statement->gotos.expression = expression;
9713         } else if (token.type == T_IDENTIFIER) {
9714                 label_t *const label = get_label();
9715                 label->used            = true;
9716                 statement->gotos.label = label;
9717         } else {
9718                 if (GNU_MODE)
9719                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9720                 else
9721                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9722                 eat_until_anchor();
9723                 return create_invalid_statement();
9724         }
9725
9726         /* remember the goto's in a list for later checking */
9727         *goto_anchor = &statement->gotos;
9728         goto_anchor  = &statement->gotos.next;
9729
9730         expect(';', end_error);
9731
9732 end_error:
9733         return statement;
9734 }
9735
9736 /**
9737  * Parse a continue statement.
9738  */
9739 static statement_t *parse_continue(void)
9740 {
9741         if (current_loop == NULL) {
9742                 errorf(HERE, "continue statement not within loop");
9743         }
9744
9745         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9746
9747         eat(T_continue);
9748         expect(';', end_error);
9749
9750 end_error:
9751         return statement;
9752 }
9753
9754 /**
9755  * Parse a break statement.
9756  */
9757 static statement_t *parse_break(void)
9758 {
9759         if (current_switch == NULL && current_loop == NULL) {
9760                 errorf(HERE, "break statement not within loop or switch");
9761         }
9762
9763         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9764
9765         eat(T_break);
9766         expect(';', end_error);
9767
9768 end_error:
9769         return statement;
9770 }
9771
9772 /**
9773  * Parse a __leave statement.
9774  */
9775 static statement_t *parse_leave_statement(void)
9776 {
9777         if (current_try == NULL) {
9778                 errorf(HERE, "__leave statement not within __try");
9779         }
9780
9781         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9782
9783         eat(T___leave);
9784         expect(';', end_error);
9785
9786 end_error:
9787         return statement;
9788 }
9789
9790 /**
9791  * Check if a given entity represents a local variable.
9792  */
9793 static bool is_local_variable(const entity_t *entity)
9794 {
9795         if (entity->kind != ENTITY_VARIABLE)
9796                 return false;
9797
9798         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9799         case STORAGE_CLASS_AUTO:
9800         case STORAGE_CLASS_REGISTER: {
9801                 const type_t *type = skip_typeref(entity->declaration.type);
9802                 if (is_type_function(type)) {
9803                         return false;
9804                 } else {
9805                         return true;
9806                 }
9807         }
9808         default:
9809                 return false;
9810         }
9811 }
9812
9813 /**
9814  * Check if a given expression represents a local variable.
9815  */
9816 static bool expression_is_local_variable(const expression_t *expression)
9817 {
9818         if (expression->base.kind != EXPR_REFERENCE) {
9819                 return false;
9820         }
9821         const entity_t *entity = expression->reference.entity;
9822         return is_local_variable(entity);
9823 }
9824
9825 /**
9826  * Check if a given expression represents a local variable and
9827  * return its declaration then, else return NULL.
9828  */
9829 entity_t *expression_is_variable(const expression_t *expression)
9830 {
9831         if (expression->base.kind != EXPR_REFERENCE) {
9832                 return NULL;
9833         }
9834         entity_t *entity = expression->reference.entity;
9835         if (entity->kind != ENTITY_VARIABLE)
9836                 return NULL;
9837
9838         return entity;
9839 }
9840
9841 /**
9842  * Parse a return statement.
9843  */
9844 static statement_t *parse_return(void)
9845 {
9846         eat(T_return);
9847
9848         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9849
9850         expression_t *return_value = NULL;
9851         if (token.type != ';') {
9852                 return_value = parse_expression();
9853                 mark_vars_read(return_value, NULL);
9854         }
9855
9856         const type_t *const func_type = skip_typeref(current_function->base.type);
9857         assert(is_type_function(func_type));
9858         type_t *const return_type = skip_typeref(func_type->function.return_type);
9859
9860         source_position_t const *const pos = &statement->base.source_position;
9861         if (return_value != NULL) {
9862                 type_t *return_value_type = skip_typeref(return_value->base.type);
9863
9864                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9865                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
9866                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9867                                 /* Only warn in C mode, because GCC does the same */
9868                                 if (c_mode & _CXX || strict_mode) {
9869                                         errorf(pos,
9870                                                         "'return' with a value, in function returning 'void'");
9871                                 } else if (warning.other) {
9872                                         warningf(pos,
9873                                                         "'return' with a value, in function returning 'void'");
9874                                 }
9875                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9876                                 /* Only warn in C mode, because GCC does the same */
9877                                 if (strict_mode) {
9878                                         errorf(pos,
9879                                                         "'return' with expression in function returning 'void'");
9880                                 } else if (warning.other) {
9881                                         warningf(pos,
9882                                                         "'return' with expression in function returning 'void'");
9883                                 }
9884                         }
9885                 } else {
9886                         assign_error_t error = semantic_assign(return_type, return_value);
9887                         report_assign_error(error, return_type, return_value, "'return'",
9888                                             pos);
9889                 }
9890                 return_value = create_implicit_cast(return_value, return_type);
9891                 /* check for returning address of a local var */
9892                 if (warning.other && return_value != NULL
9893                     && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9894                         const expression_t *expression = return_value->unary.value;
9895                         if (expression_is_local_variable(expression)) {
9896                                 warningf(pos, "function returns address of local variable");
9897                         }
9898                 }
9899         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
9900                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9901                 if (c_mode & _CXX || strict_mode) {
9902                         errorf(pos,
9903                                "'return' without value, in function returning non-void");
9904                 } else {
9905                         warningf(pos,
9906                                  "'return' without value, in function returning non-void");
9907                 }
9908         }
9909         statement->returns.value = return_value;
9910
9911         expect(';', end_error);
9912
9913 end_error:
9914         return statement;
9915 }
9916
9917 /**
9918  * Parse a declaration statement.
9919  */
9920 static statement_t *parse_declaration_statement(void)
9921 {
9922         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9923
9924         entity_t *before = current_scope->last_entity;
9925         if (GNU_MODE) {
9926                 parse_external_declaration();
9927         } else {
9928                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9929         }
9930
9931         declaration_statement_t *const decl  = &statement->declaration;
9932         entity_t                *const begin =
9933                 before != NULL ? before->base.next : current_scope->entities;
9934         decl->declarations_begin = begin;
9935         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9936
9937         return statement;
9938 }
9939
9940 /**
9941  * Parse an expression statement, ie. expr ';'.
9942  */
9943 static statement_t *parse_expression_statement(void)
9944 {
9945         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9946
9947         expression_t *const expr         = parse_expression();
9948         statement->expression.expression = expr;
9949         mark_vars_read(expr, ENT_ANY);
9950
9951         expect(';', end_error);
9952
9953 end_error:
9954         return statement;
9955 }
9956
9957 /**
9958  * Parse a microsoft __try { } __finally { } or
9959  * __try{ } __except() { }
9960  */
9961 static statement_t *parse_ms_try_statment(void)
9962 {
9963         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9964         eat(T___try);
9965
9966         PUSH_PARENT(statement);
9967
9968         ms_try_statement_t *rem = current_try;
9969         current_try = &statement->ms_try;
9970         statement->ms_try.try_statement = parse_compound_statement(false);
9971         current_try = rem;
9972
9973         POP_PARENT;
9974
9975         if (next_if(T___except)) {
9976                 expect('(', end_error);
9977                 add_anchor_token(')');
9978                 expression_t *const expr = parse_expression();
9979                 mark_vars_read(expr, NULL);
9980                 type_t       *      type = skip_typeref(expr->base.type);
9981                 if (is_type_integer(type)) {
9982                         type = promote_integer(type);
9983                 } else if (is_type_valid(type)) {
9984                         errorf(&expr->base.source_position,
9985                                "__expect expression is not an integer, but '%T'", type);
9986                         type = type_error_type;
9987                 }
9988                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9989                 rem_anchor_token(')');
9990                 expect(')', end_error);
9991                 statement->ms_try.final_statement = parse_compound_statement(false);
9992         } else if (next_if(T__finally)) {
9993                 statement->ms_try.final_statement = parse_compound_statement(false);
9994         } else {
9995                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9996                 return create_invalid_statement();
9997         }
9998         return statement;
9999 end_error:
10000         return create_invalid_statement();
10001 }
10002
10003 static statement_t *parse_empty_statement(void)
10004 {
10005         if (warning.empty_statement) {
10006                 warningf(HERE, "statement is empty");
10007         }
10008         statement_t *const statement = create_empty_statement();
10009         eat(';');
10010         return statement;
10011 }
10012
10013 static statement_t *parse_local_label_declaration(void)
10014 {
10015         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10016
10017         eat(T___label__);
10018
10019         entity_t *begin   = NULL;
10020         entity_t *end     = NULL;
10021         entity_t **anchor = &begin;
10022         do {
10023                 if (token.type != T_IDENTIFIER) {
10024                         parse_error_expected("while parsing local label declaration",
10025                                 T_IDENTIFIER, NULL);
10026                         goto end_error;
10027                 }
10028                 symbol_t *symbol = token.symbol;
10029                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10030                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10031                         source_position_t const *const ppos = &entity->base.source_position;
10032                         errorf(HERE, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
10033                 } else {
10034                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol);
10035                         entity->base.parent_scope    = current_scope;
10036                         entity->base.source_position = token.source_position;
10037
10038                         *anchor = entity;
10039                         anchor  = &entity->base.next;
10040                         end     = entity;
10041
10042                         environment_push(entity);
10043                 }
10044                 next_token();
10045         } while (next_if(','));
10046         expect(';', end_error);
10047 end_error:
10048         statement->declaration.declarations_begin = begin;
10049         statement->declaration.declarations_end   = end;
10050         return statement;
10051 }
10052
10053 static void parse_namespace_definition(void)
10054 {
10055         eat(T_namespace);
10056
10057         entity_t *entity = NULL;
10058         symbol_t *symbol = NULL;
10059
10060         if (token.type == T_IDENTIFIER) {
10061                 symbol = token.symbol;
10062                 next_token();
10063
10064                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10065                 if (entity != NULL
10066                                 && entity->kind != ENTITY_NAMESPACE
10067                                 && entity->base.parent_scope == current_scope) {
10068                         if (is_entity_valid(entity)) {
10069                                 error_redefined_as_different_kind(&token.source_position,
10070                                                 entity, ENTITY_NAMESPACE);
10071                         }
10072                         entity = NULL;
10073                 }
10074         }
10075
10076         if (entity == NULL) {
10077                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol);
10078                 entity->base.source_position = token.source_position;
10079                 entity->base.parent_scope    = current_scope;
10080         }
10081
10082         if (token.type == '=') {
10083                 /* TODO: parse namespace alias */
10084                 panic("namespace alias definition not supported yet");
10085         }
10086
10087         environment_push(entity);
10088         append_entity(current_scope, entity);
10089
10090         size_t const  top       = environment_top();
10091         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10092
10093         entity_t     *old_current_entity = current_entity;
10094         current_entity = entity;
10095
10096         expect('{', end_error);
10097         parse_externals();
10098         expect('}', end_error);
10099
10100 end_error:
10101         assert(current_scope == &entity->namespacee.members);
10102         assert(current_entity == entity);
10103         current_entity = old_current_entity;
10104         scope_pop(old_scope);
10105         environment_pop_to(top);
10106 }
10107
10108 /**
10109  * Parse a statement.
10110  * There's also parse_statement() which additionally checks for
10111  * "statement has no effect" warnings
10112  */
10113 static statement_t *intern_parse_statement(void)
10114 {
10115         statement_t *statement = NULL;
10116
10117         /* declaration or statement */
10118         add_anchor_token(';');
10119         switch (token.type) {
10120         case T_IDENTIFIER: {
10121                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10122                 if (la1_type == ':') {
10123                         statement = parse_label_statement();
10124                 } else if (is_typedef_symbol(token.symbol)) {
10125                         statement = parse_declaration_statement();
10126                 } else {
10127                         /* it's an identifier, the grammar says this must be an
10128                          * expression statement. However it is common that users mistype
10129                          * declaration types, so we guess a bit here to improve robustness
10130                          * for incorrect programs */
10131                         switch (la1_type) {
10132                         case '&':
10133                         case '*':
10134                                 if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL) {
10135                         default:
10136                                         statement = parse_expression_statement();
10137                                 } else {
10138                         DECLARATION_START
10139                         case T_IDENTIFIER:
10140                                         statement = parse_declaration_statement();
10141                                 }
10142                                 break;
10143                         }
10144                 }
10145                 break;
10146         }
10147
10148         case T___extension__:
10149                 /* This can be a prefix to a declaration or an expression statement.
10150                  * We simply eat it now and parse the rest with tail recursion. */
10151                 while (next_if(T___extension__)) {}
10152                 bool old_gcc_extension = in_gcc_extension;
10153                 in_gcc_extension       = true;
10154                 statement = intern_parse_statement();
10155                 in_gcc_extension = old_gcc_extension;
10156                 break;
10157
10158         DECLARATION_START
10159                 statement = parse_declaration_statement();
10160                 break;
10161
10162         case T___label__:
10163                 statement = parse_local_label_declaration();
10164                 break;
10165
10166         case ';':         statement = parse_empty_statement();         break;
10167         case '{':         statement = parse_compound_statement(false); break;
10168         case T___leave:   statement = parse_leave_statement();         break;
10169         case T___try:     statement = parse_ms_try_statment();         break;
10170         case T_asm:       statement = parse_asm_statement();           break;
10171         case T_break:     statement = parse_break();                   break;
10172         case T_case:      statement = parse_case_statement();          break;
10173         case T_continue:  statement = parse_continue();                break;
10174         case T_default:   statement = parse_default_statement();       break;
10175         case T_do:        statement = parse_do();                      break;
10176         case T_for:       statement = parse_for();                     break;
10177         case T_goto:      statement = parse_goto();                    break;
10178         case T_if:        statement = parse_if();                      break;
10179         case T_return:    statement = parse_return();                  break;
10180         case T_switch:    statement = parse_switch();                  break;
10181         case T_while:     statement = parse_while();                   break;
10182
10183         EXPRESSION_START
10184                 statement = parse_expression_statement();
10185                 break;
10186
10187         default:
10188                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10189                 statement = create_invalid_statement();
10190                 if (!at_anchor())
10191                         next_token();
10192                 break;
10193         }
10194         rem_anchor_token(';');
10195
10196         assert(statement != NULL
10197                         && statement->base.source_position.input_name != NULL);
10198
10199         return statement;
10200 }
10201
10202 /**
10203  * parse a statement and emits "statement has no effect" warning if needed
10204  * (This is really a wrapper around intern_parse_statement with check for 1
10205  *  single warning. It is needed, because for statement expressions we have
10206  *  to avoid the warning on the last statement)
10207  */
10208 static statement_t *parse_statement(void)
10209 {
10210         statement_t *statement = intern_parse_statement();
10211
10212         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10213                 expression_t *expression = statement->expression.expression;
10214                 if (!expression_has_effect(expression)) {
10215                         warningf(&expression->base.source_position,
10216                                         "statement has no effect");
10217                 }
10218         }
10219
10220         return statement;
10221 }
10222
10223 /**
10224  * Parse a compound statement.
10225  */
10226 static statement_t *parse_compound_statement(bool inside_expression_statement)
10227 {
10228         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10229
10230         PUSH_PARENT(statement);
10231
10232         eat('{');
10233         add_anchor_token('}');
10234         /* tokens, which can start a statement */
10235         /* TODO MS, __builtin_FOO */
10236         add_anchor_token('!');
10237         add_anchor_token('&');
10238         add_anchor_token('(');
10239         add_anchor_token('*');
10240         add_anchor_token('+');
10241         add_anchor_token('-');
10242         add_anchor_token('{');
10243         add_anchor_token('~');
10244         add_anchor_token(T_CHARACTER_CONSTANT);
10245         add_anchor_token(T_COLONCOLON);
10246         add_anchor_token(T_FLOATINGPOINT);
10247         add_anchor_token(T_IDENTIFIER);
10248         add_anchor_token(T_INTEGER);
10249         add_anchor_token(T_MINUSMINUS);
10250         add_anchor_token(T_PLUSPLUS);
10251         add_anchor_token(T_STRING_LITERAL);
10252         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10253         add_anchor_token(T_WIDE_STRING_LITERAL);
10254         add_anchor_token(T__Bool);
10255         add_anchor_token(T__Complex);
10256         add_anchor_token(T__Imaginary);
10257         add_anchor_token(T___FUNCTION__);
10258         add_anchor_token(T___PRETTY_FUNCTION__);
10259         add_anchor_token(T___alignof__);
10260         add_anchor_token(T___attribute__);
10261         add_anchor_token(T___builtin_va_start);
10262         add_anchor_token(T___extension__);
10263         add_anchor_token(T___func__);
10264         add_anchor_token(T___imag__);
10265         add_anchor_token(T___label__);
10266         add_anchor_token(T___real__);
10267         add_anchor_token(T___thread);
10268         add_anchor_token(T_asm);
10269         add_anchor_token(T_auto);
10270         add_anchor_token(T_bool);
10271         add_anchor_token(T_break);
10272         add_anchor_token(T_case);
10273         add_anchor_token(T_char);
10274         add_anchor_token(T_class);
10275         add_anchor_token(T_const);
10276         add_anchor_token(T_const_cast);
10277         add_anchor_token(T_continue);
10278         add_anchor_token(T_default);
10279         add_anchor_token(T_delete);
10280         add_anchor_token(T_double);
10281         add_anchor_token(T_do);
10282         add_anchor_token(T_dynamic_cast);
10283         add_anchor_token(T_enum);
10284         add_anchor_token(T_extern);
10285         add_anchor_token(T_false);
10286         add_anchor_token(T_float);
10287         add_anchor_token(T_for);
10288         add_anchor_token(T_goto);
10289         add_anchor_token(T_if);
10290         add_anchor_token(T_inline);
10291         add_anchor_token(T_int);
10292         add_anchor_token(T_long);
10293         add_anchor_token(T_new);
10294         add_anchor_token(T_operator);
10295         add_anchor_token(T_register);
10296         add_anchor_token(T_reinterpret_cast);
10297         add_anchor_token(T_restrict);
10298         add_anchor_token(T_return);
10299         add_anchor_token(T_short);
10300         add_anchor_token(T_signed);
10301         add_anchor_token(T_sizeof);
10302         add_anchor_token(T_static);
10303         add_anchor_token(T_static_cast);
10304         add_anchor_token(T_struct);
10305         add_anchor_token(T_switch);
10306         add_anchor_token(T_template);
10307         add_anchor_token(T_this);
10308         add_anchor_token(T_throw);
10309         add_anchor_token(T_true);
10310         add_anchor_token(T_try);
10311         add_anchor_token(T_typedef);
10312         add_anchor_token(T_typeid);
10313         add_anchor_token(T_typename);
10314         add_anchor_token(T_typeof);
10315         add_anchor_token(T_union);
10316         add_anchor_token(T_unsigned);
10317         add_anchor_token(T_using);
10318         add_anchor_token(T_void);
10319         add_anchor_token(T_volatile);
10320         add_anchor_token(T_wchar_t);
10321         add_anchor_token(T_while);
10322
10323         size_t const  top       = environment_top();
10324         scope_t      *old_scope = scope_push(&statement->compound.scope);
10325
10326         statement_t **anchor            = &statement->compound.statements;
10327         bool          only_decls_so_far = true;
10328         while (token.type != '}') {
10329                 if (token.type == T_EOF) {
10330                         errorf(&statement->base.source_position,
10331                                "EOF while parsing compound statement");
10332                         break;
10333                 }
10334                 statement_t *sub_statement = intern_parse_statement();
10335                 if (is_invalid_statement(sub_statement)) {
10336                         /* an error occurred. if we are at an anchor, return */
10337                         if (at_anchor())
10338                                 goto end_error;
10339                         continue;
10340                 }
10341
10342                 if (warning.declaration_after_statement) {
10343                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10344                                 only_decls_so_far = false;
10345                         } else if (!only_decls_so_far) {
10346                                 warningf(&sub_statement->base.source_position,
10347                                          "ISO C90 forbids mixed declarations and code");
10348                         }
10349                 }
10350
10351                 *anchor = sub_statement;
10352
10353                 while (sub_statement->base.next != NULL)
10354                         sub_statement = sub_statement->base.next;
10355
10356                 anchor = &sub_statement->base.next;
10357         }
10358         next_token();
10359
10360         /* look over all statements again to produce no effect warnings */
10361         if (warning.unused_value) {
10362                 statement_t *sub_statement = statement->compound.statements;
10363                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10364                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10365                                 continue;
10366                         /* don't emit a warning for the last expression in an expression
10367                          * statement as it has always an effect */
10368                         if (inside_expression_statement && sub_statement->base.next == NULL)
10369                                 continue;
10370
10371                         expression_t *expression = sub_statement->expression.expression;
10372                         if (!expression_has_effect(expression)) {
10373                                 warningf(&expression->base.source_position,
10374                                          "statement has no effect");
10375                         }
10376                 }
10377         }
10378
10379 end_error:
10380         rem_anchor_token(T_while);
10381         rem_anchor_token(T_wchar_t);
10382         rem_anchor_token(T_volatile);
10383         rem_anchor_token(T_void);
10384         rem_anchor_token(T_using);
10385         rem_anchor_token(T_unsigned);
10386         rem_anchor_token(T_union);
10387         rem_anchor_token(T_typeof);
10388         rem_anchor_token(T_typename);
10389         rem_anchor_token(T_typeid);
10390         rem_anchor_token(T_typedef);
10391         rem_anchor_token(T_try);
10392         rem_anchor_token(T_true);
10393         rem_anchor_token(T_throw);
10394         rem_anchor_token(T_this);
10395         rem_anchor_token(T_template);
10396         rem_anchor_token(T_switch);
10397         rem_anchor_token(T_struct);
10398         rem_anchor_token(T_static_cast);
10399         rem_anchor_token(T_static);
10400         rem_anchor_token(T_sizeof);
10401         rem_anchor_token(T_signed);
10402         rem_anchor_token(T_short);
10403         rem_anchor_token(T_return);
10404         rem_anchor_token(T_restrict);
10405         rem_anchor_token(T_reinterpret_cast);
10406         rem_anchor_token(T_register);
10407         rem_anchor_token(T_operator);
10408         rem_anchor_token(T_new);
10409         rem_anchor_token(T_long);
10410         rem_anchor_token(T_int);
10411         rem_anchor_token(T_inline);
10412         rem_anchor_token(T_if);
10413         rem_anchor_token(T_goto);
10414         rem_anchor_token(T_for);
10415         rem_anchor_token(T_float);
10416         rem_anchor_token(T_false);
10417         rem_anchor_token(T_extern);
10418         rem_anchor_token(T_enum);
10419         rem_anchor_token(T_dynamic_cast);
10420         rem_anchor_token(T_do);
10421         rem_anchor_token(T_double);
10422         rem_anchor_token(T_delete);
10423         rem_anchor_token(T_default);
10424         rem_anchor_token(T_continue);
10425         rem_anchor_token(T_const_cast);
10426         rem_anchor_token(T_const);
10427         rem_anchor_token(T_class);
10428         rem_anchor_token(T_char);
10429         rem_anchor_token(T_case);
10430         rem_anchor_token(T_break);
10431         rem_anchor_token(T_bool);
10432         rem_anchor_token(T_auto);
10433         rem_anchor_token(T_asm);
10434         rem_anchor_token(T___thread);
10435         rem_anchor_token(T___real__);
10436         rem_anchor_token(T___label__);
10437         rem_anchor_token(T___imag__);
10438         rem_anchor_token(T___func__);
10439         rem_anchor_token(T___extension__);
10440         rem_anchor_token(T___builtin_va_start);
10441         rem_anchor_token(T___attribute__);
10442         rem_anchor_token(T___alignof__);
10443         rem_anchor_token(T___PRETTY_FUNCTION__);
10444         rem_anchor_token(T___FUNCTION__);
10445         rem_anchor_token(T__Imaginary);
10446         rem_anchor_token(T__Complex);
10447         rem_anchor_token(T__Bool);
10448         rem_anchor_token(T_WIDE_STRING_LITERAL);
10449         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10450         rem_anchor_token(T_STRING_LITERAL);
10451         rem_anchor_token(T_PLUSPLUS);
10452         rem_anchor_token(T_MINUSMINUS);
10453         rem_anchor_token(T_INTEGER);
10454         rem_anchor_token(T_IDENTIFIER);
10455         rem_anchor_token(T_FLOATINGPOINT);
10456         rem_anchor_token(T_COLONCOLON);
10457         rem_anchor_token(T_CHARACTER_CONSTANT);
10458         rem_anchor_token('~');
10459         rem_anchor_token('{');
10460         rem_anchor_token('-');
10461         rem_anchor_token('+');
10462         rem_anchor_token('*');
10463         rem_anchor_token('(');
10464         rem_anchor_token('&');
10465         rem_anchor_token('!');
10466         rem_anchor_token('}');
10467         assert(current_scope == &statement->compound.scope);
10468         scope_pop(old_scope);
10469         environment_pop_to(top);
10470
10471         POP_PARENT;
10472         return statement;
10473 }
10474
10475 /**
10476  * Check for unused global static functions and variables
10477  */
10478 static void check_unused_globals(void)
10479 {
10480         if (!warning.unused_function && !warning.unused_variable)
10481                 return;
10482
10483         for (const entity_t *entity = file_scope->entities; entity != NULL;
10484              entity = entity->base.next) {
10485                 if (!is_declaration(entity))
10486                         continue;
10487
10488                 const declaration_t *declaration = &entity->declaration;
10489                 if (declaration->used                  ||
10490                     declaration->modifiers & DM_UNUSED ||
10491                     declaration->modifiers & DM_USED   ||
10492                     declaration->storage_class != STORAGE_CLASS_STATIC)
10493                         continue;
10494
10495                 const char *s;
10496                 if (entity->kind == ENTITY_FUNCTION) {
10497                         /* inhibit warning for static inline functions */
10498                         if (entity->function.is_inline)
10499                                 continue;
10500
10501                         s = entity->function.statement != NULL ? "defined" : "declared";
10502                 } else {
10503                         s = "defined";
10504                 }
10505
10506                 warningf(&declaration->base.source_position, "'%#N' %s but not used", entity);
10507         }
10508 }
10509
10510 static void parse_global_asm(void)
10511 {
10512         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10513
10514         eat(T_asm);
10515         expect('(', end_error);
10516
10517         statement->asms.asm_text = parse_string_literals();
10518         statement->base.next     = unit->global_asm;
10519         unit->global_asm         = statement;
10520
10521         expect(')', end_error);
10522         expect(';', end_error);
10523
10524 end_error:;
10525 }
10526
10527 static void parse_linkage_specification(void)
10528 {
10529         eat(T_extern);
10530
10531         source_position_t const pos     = *HERE;
10532         char const       *const linkage = parse_string_literals().begin;
10533
10534         linkage_kind_t old_linkage = current_linkage;
10535         linkage_kind_t new_linkage;
10536         if (strcmp(linkage, "C") == 0) {
10537                 new_linkage = LINKAGE_C;
10538         } else if (strcmp(linkage, "C++") == 0) {
10539                 new_linkage = LINKAGE_CXX;
10540         } else {
10541                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10542                 new_linkage = LINKAGE_INVALID;
10543         }
10544         current_linkage = new_linkage;
10545
10546         if (next_if('{')) {
10547                 parse_externals();
10548                 expect('}', end_error);
10549         } else {
10550                 parse_external();
10551         }
10552
10553 end_error:
10554         assert(current_linkage == new_linkage);
10555         current_linkage = old_linkage;
10556 }
10557
10558 static void parse_external(void)
10559 {
10560         switch (token.type) {
10561                 DECLARATION_START_NO_EXTERN
10562                 case T_IDENTIFIER:
10563                 case T___extension__:
10564                 /* tokens below are for implicit int */
10565                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10566                              implicit int) */
10567                 case '*': /* * x; -> int* x; */
10568                 case '(': /* (x); -> int (x); */
10569                         parse_external_declaration();
10570                         return;
10571
10572                 case T_extern:
10573                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10574                                 parse_linkage_specification();
10575                         } else {
10576                                 parse_external_declaration();
10577                         }
10578                         return;
10579
10580                 case T_asm:
10581                         parse_global_asm();
10582                         return;
10583
10584                 case T_namespace:
10585                         parse_namespace_definition();
10586                         return;
10587
10588                 case ';':
10589                         if (!strict_mode) {
10590                                 if (warning.other)
10591                                         warningf(HERE, "stray ';' outside of function");
10592                                 next_token();
10593                                 return;
10594                         }
10595                         /* FALLTHROUGH */
10596
10597                 default:
10598                         errorf(HERE, "stray %K outside of function", &token);
10599                         if (token.type == '(' || token.type == '{' || token.type == '[')
10600                                 eat_until_matching_token(token.type);
10601                         next_token();
10602                         return;
10603         }
10604 }
10605
10606 static void parse_externals(void)
10607 {
10608         add_anchor_token('}');
10609         add_anchor_token(T_EOF);
10610
10611 #ifndef NDEBUG
10612         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10613         unsigned char token_anchor_copy[T_LAST_TOKEN];
10614         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10615 #endif
10616
10617         while (token.type != T_EOF && token.type != '}') {
10618 #ifndef NDEBUG
10619                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10620                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10621                         if (count != 0) {
10622                                 /* the anchor set and its copy differs */
10623                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10624                         }
10625                 }
10626                 if (in_gcc_extension) {
10627                         /* an gcc extension scope was not closed */
10628                         internal_errorf(HERE, "Leaked __extension__");
10629                 }
10630 #endif
10631
10632                 parse_external();
10633         }
10634
10635         rem_anchor_token(T_EOF);
10636         rem_anchor_token('}');
10637 }
10638
10639 /**
10640  * Parse a translation unit.
10641  */
10642 static void parse_translation_unit(void)
10643 {
10644         add_anchor_token(T_EOF);
10645
10646         while (true) {
10647                 parse_externals();
10648
10649                 if (token.type == T_EOF)
10650                         break;
10651
10652                 errorf(HERE, "stray %K outside of function", &token);
10653                 if (token.type == '(' || token.type == '{' || token.type == '[')
10654                         eat_until_matching_token(token.type);
10655                 next_token();
10656         }
10657 }
10658
10659 void set_default_visibility(elf_visibility_tag_t visibility)
10660 {
10661         default_visibility = visibility;
10662 }
10663
10664 /**
10665  * Parse the input.
10666  *
10667  * @return  the translation unit or NULL if errors occurred.
10668  */
10669 void start_parsing(void)
10670 {
10671         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10672         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10673         diagnostic_count  = 0;
10674         error_count       = 0;
10675         warning_count     = 0;
10676
10677         print_to_file(stderr);
10678
10679         assert(unit == NULL);
10680         unit = allocate_ast_zero(sizeof(unit[0]));
10681
10682         assert(file_scope == NULL);
10683         file_scope = &unit->scope;
10684
10685         assert(current_scope == NULL);
10686         scope_push(&unit->scope);
10687
10688         create_gnu_builtins();
10689         if (c_mode & _MS)
10690                 create_microsoft_intrinsics();
10691 }
10692
10693 translation_unit_t *finish_parsing(void)
10694 {
10695         assert(current_scope == &unit->scope);
10696         scope_pop(NULL);
10697
10698         assert(file_scope == &unit->scope);
10699         check_unused_globals();
10700         file_scope = NULL;
10701
10702         DEL_ARR_F(environment_stack);
10703         DEL_ARR_F(label_stack);
10704
10705         translation_unit_t *result = unit;
10706         unit = NULL;
10707         return result;
10708 }
10709
10710 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10711  * are given length one. */
10712 static void complete_incomplete_arrays(void)
10713 {
10714         size_t n = ARR_LEN(incomplete_arrays);
10715         for (size_t i = 0; i != n; ++i) {
10716                 declaration_t *const decl = incomplete_arrays[i];
10717                 type_t        *const type = skip_typeref(decl->type);
10718
10719                 if (!is_type_incomplete(type))
10720                         continue;
10721
10722                 if (warning.other) {
10723                         source_position_t const *const pos = &decl->base.source_position;
10724                         warningf(pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10725                 }
10726
10727                 type_t *const new_type = duplicate_type(type);
10728                 new_type->array.size_constant     = true;
10729                 new_type->array.has_implicit_size = true;
10730                 new_type->array.size              = 1;
10731
10732                 type_t *const result = identify_new_type(new_type);
10733
10734                 decl->type = result;
10735         }
10736 }
10737
10738 void prepare_main_collect2(entity_t *entity)
10739 {
10740         // create call to __main
10741         symbol_t *symbol         = symbol_table_insert("__main");
10742         entity_t *subsubmain_ent
10743                 = create_implicit_function(symbol, &builtin_source_position);
10744
10745         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10746         type_t       *ftype       = subsubmain_ent->declaration.type;
10747         ref->base.source_position = builtin_source_position;
10748         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10749         ref->reference.entity     = subsubmain_ent;
10750
10751         expression_t *call = allocate_expression_zero(EXPR_CALL);
10752         call->base.source_position = builtin_source_position;
10753         call->base.type            = type_void;
10754         call->call.function        = ref;
10755
10756         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10757         expr_statement->base.source_position  = builtin_source_position;
10758         expr_statement->expression.expression = call;
10759
10760         statement_t *statement = entity->function.statement;
10761         assert(statement->kind == STATEMENT_COMPOUND);
10762         compound_statement_t *compounds = &statement->compound;
10763
10764         expr_statement->base.next = compounds->statements;
10765         compounds->statements     = expr_statement;
10766 }
10767
10768 void parse(void)
10769 {
10770         lookahead_bufpos = 0;
10771         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10772                 next_token();
10773         }
10774         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10775         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10776         parse_translation_unit();
10777         complete_incomplete_arrays();
10778         DEL_ARR_F(incomplete_arrays);
10779         incomplete_arrays = NULL;
10780 }
10781
10782 /**
10783  * Initialize the parser.
10784  */
10785 void init_parser(void)
10786 {
10787         sym_anonymous = symbol_table_insert("<anonymous>");
10788
10789         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10790
10791         init_expression_parsers();
10792         obstack_init(&temp_obst);
10793 }
10794
10795 /**
10796  * Terminate the parser.
10797  */
10798 void exit_parser(void)
10799 {
10800         obstack_free(&temp_obst, NULL);
10801 }