nsz Git - cparser/blob - parser.c

   1 /*
   2  * This file is part of cparser.
   3  * Copyright (C) 2007-2009 Matthias Braun <matze@braunis.de>
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18  * 02111-1307, USA.
  19  */
  20 #include <config.h>
  21
  22 #include <assert.h>
  23 #include <stdarg.h>
  24 #include <stdbool.h>
  25
  26 #include "parser.h"
  27 #include "diagnostic.h"
  28 #include "format_check.h"
  29 #include "lexer.h"
  30 #include "symbol_t.h"
  31 #include "token_t.h"
  32 #include "types.h"
  33 #include "type_t.h"
  34 #include "type_hash.h"
  35 #include "ast_t.h"
  36 #include "entity_t.h"
  37 #include "attribute_t.h"
  38 #include "lang_features.h"
  39 #include "walk_statements.h"
  40 #include "warning.h"
  41 #include "printer.h"
  42 #include "adt/bitfiddle.h"
  43 #include "adt/error.h"
  44 #include "adt/array.h"
  45
  46 //#define PRINT_TOKENS
  47 #define MAX_LOOKAHEAD 1
  48
  49 typedef struct {
  50         entity_t           *old_entity;
  51         symbol_t           *symbol;
  52         entity_namespace_t  namespc;
  53 } stack_entry_t;
  54
  55 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  56 struct declaration_specifiers_t {
  57         source_position_t  source_position;
  58         storage_class_t    storage_class;
  59         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  60         bool               is_inline    : 1;
  61         bool               thread_local : 1;  /**< GCC __thread */
  62         attribute_t       *attributes;        /**< list of attributes */
  63         type_t            *type;
  64 };
  65
  66 /**
  67  * An environment for parsing initializers (and compound literals).
  68  */
  69 typedef struct parse_initializer_env_t {
  70         type_t     *type;   /**< the type of the initializer. In case of an
  71                                  array type with unspecified size this gets
  72                                  adjusted to the actual size. */
  73         entity_t   *entity; /**< the variable that is initialized if any */
  74         bool        must_be_constant;
  75 } parse_initializer_env_t;
  76
  77 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  78
  79 /** The current token. */
  80 static token_t              token;
  81 /** The lookahead ring-buffer. */
  82 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  83 /** Position of the next token in the lookahead buffer. */
  84 static size_t               lookahead_bufpos;
  85 static stack_entry_t       *environment_stack = NULL;
  86 static stack_entry_t       *label_stack       = NULL;
  87 static scope_t             *file_scope        = NULL;
  88 static scope_t             *current_scope     = NULL;
  89 /** Point to the current function declaration if inside a function. */
  90 static function_t          *current_function  = NULL;
  91 static entity_t            *current_entity    = NULL;
  92 static entity_t            *current_init_decl = NULL;
  93 static switch_statement_t  *current_switch    = NULL;
  94 static statement_t         *current_loop      = NULL;
  95 static statement_t         *current_parent    = NULL;
  96 static ms_try_statement_t  *current_try       = NULL;
  97 static linkage_kind_t       current_linkage   = LINKAGE_INVALID;
  98 static goto_statement_t    *goto_first        = NULL;
  99 static goto_statement_t   **goto_anchor       = NULL;
 100 static label_statement_t   *label_first       = NULL;
 101 static label_statement_t  **label_anchor      = NULL;
 102 /** current translation unit. */
 103 static translation_unit_t  *unit              = NULL;
 104 /** true if we are in a type property context (evaluation only for type) */
 105 static bool                 in_type_prop      = false;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_PARENT(stmt)                          \
 115         statement_t *const prev_parent = current_parent; \
 116         ((void)(current_parent = (stmt)))
 117 #define POP_PARENT ((void)(current_parent = prev_parent))
 118
 119 /** special symbol used for anonymous entities. */
 120 static symbol_t *sym_anonymous = NULL;
 121
 122 /** The token anchor set */
 123 static unsigned char token_anchor_set[T_LAST_TOKEN];
 124
 125 /** The current source position. */
 126 #define HERE (&token.source_position)
 127
 128 /** true if we are in GCC mode. */
 129 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 130
 131 static statement_t *parse_compound_statement(bool inside_expression_statement);
 132 static statement_t *parse_statement(void);
 133
 134 static expression_t *parse_subexpression(precedence_t);
 135 static expression_t *parse_expression(void);
 136 static type_t       *parse_typename(void);
 137 static void          parse_externals(void);
 138 static void          parse_external(void);
 139
 140 static void parse_compound_type_entries(compound_t *compound_declaration);
 141
 142 static void check_call_argument(type_t          *expected_type,
 143                                                                 call_argument_t *argument, unsigned pos);
 144
 145 typedef enum declarator_flags_t {
 146         DECL_FLAGS_NONE             = 0,
 147         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 148         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 149         DECL_IS_PARAMETER           = 1U << 2
 150 } declarator_flags_t;
 151
 152 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 153                                   declarator_flags_t flags);
 154
 155 static void semantic_comparison(binary_expression_t *expression);
 156
 157 #define STORAGE_CLASSES       \
 158         STORAGE_CLASSES_NO_EXTERN \
 159         case T_extern:
 160
 161 #define STORAGE_CLASSES_NO_EXTERN \
 162         case T_typedef:         \
 163         case T_static:          \
 164         case T_auto:            \
 165         case T_register:        \
 166         case T___thread:
 167
 168 #define TYPE_QUALIFIERS     \
 169         case T_const:           \
 170         case T_restrict:        \
 171         case T_volatile:        \
 172         case T_inline:          \
 173         case T__forceinline:    \
 174         case T___attribute__:
 175
 176 #define COMPLEX_SPECIFIERS  \
 177         case T__Complex:
 178 #define IMAGINARY_SPECIFIERS \
 179         case T__Imaginary:
 180
 181 #define TYPE_SPECIFIERS       \
 182         case T__Bool:             \
 183         case T___builtin_va_list: \
 184         case T___typeof__:        \
 185         case T__declspec:         \
 186         case T_bool:              \
 187         case T_char:              \
 188         case T_double:            \
 189         case T_enum:              \
 190         case T_float:             \
 191         case T_int:               \
 192         case T_long:              \
 193         case T_short:             \
 194         case T_signed:            \
 195         case T_struct:            \
 196         case T_union:             \
 197         case T_unsigned:          \
 198         case T_void:              \
 199         case T_wchar_t:           \
 200         case T__int8:             \
 201         case T__int16:            \
 202         case T__int32:            \
 203         case T__int64:            \
 204         case T__int128:           \
 205         COMPLEX_SPECIFIERS        \
 206         IMAGINARY_SPECIFIERS
 207
 208 #define DECLARATION_START   \
 209         STORAGE_CLASSES         \
 210         TYPE_QUALIFIERS         \
 211         TYPE_SPECIFIERS
 212
 213 #define DECLARATION_START_NO_EXTERN \
 214         STORAGE_CLASSES_NO_EXTERN       \
 215         TYPE_QUALIFIERS                 \
 216         TYPE_SPECIFIERS
 217
 218 #define TYPENAME_START      \
 219         TYPE_QUALIFIERS         \
 220         TYPE_SPECIFIERS
 221
 222 #define EXPRESSION_START              \
 223         case '!':                         \
 224         case '&':                         \
 225         case '(':                         \
 226         case '*':                         \
 227         case '+':                         \
 228         case '-':                         \
 229         case '~':                         \
 230         case T_ANDAND:                    \
 231         case T_CHARACTER_CONSTANT:        \
 232         case T_FLOATINGPOINT:             \
 233         case T_FLOATINGPOINT_HEXADECIMAL: \
 234         case T_INTEGER:                   \
 235         case T_INTEGER_HEXADECIMAL:       \
 236         case T_INTEGER_OCTAL:             \
 237         case T_MINUSMINUS:                \
 238         case T_PLUSPLUS:                  \
 239         case T_STRING_LITERAL:            \
 240         case T_WIDE_CHARACTER_CONSTANT:   \
 241         case T_WIDE_STRING_LITERAL:       \
 242         case T___FUNCDNAME__:             \
 243         case T___FUNCSIG__:               \
 244         case T___FUNCTION__:              \
 245         case T___PRETTY_FUNCTION__:       \
 246         case T___alignof__:               \
 247         case T___builtin_classify_type:   \
 248         case T___builtin_constant_p:      \
 249         case T___builtin_isgreater:       \
 250         case T___builtin_isgreaterequal:  \
 251         case T___builtin_isless:          \
 252         case T___builtin_islessequal:     \
 253         case T___builtin_islessgreater:   \
 254         case T___builtin_isunordered:     \
 255         case T___builtin_offsetof:        \
 256         case T___builtin_va_arg:          \
 257         case T___builtin_va_copy:         \
 258         case T___builtin_va_start:        \
 259         case T___func__:                  \
 260         case T___noop:                    \
 261         case T__assume:                   \
 262         case T_delete:                    \
 263         case T_false:                     \
 264         case T_sizeof:                    \
 265         case T_throw:                     \
 266         case T_true:
 267
 268 /**
 269  * Returns the size of a statement node.
 270  *
 271  * @param kind  the statement kind
 272  */
 273 static size_t get_statement_struct_size(statement_kind_t kind)
 274 {
 275         static const size_t sizes[] = {
 276                 [STATEMENT_INVALID]     = sizeof(invalid_statement_t),
 277                 [STATEMENT_EMPTY]       = sizeof(empty_statement_t),
 278                 [STATEMENT_COMPOUND]    = sizeof(compound_statement_t),
 279                 [STATEMENT_RETURN]      = sizeof(return_statement_t),
 280                 [STATEMENT_DECLARATION] = sizeof(declaration_statement_t),
 281                 [STATEMENT_IF]          = sizeof(if_statement_t),
 282                 [STATEMENT_SWITCH]      = sizeof(switch_statement_t),
 283                 [STATEMENT_EXPRESSION]  = sizeof(expression_statement_t),
 284                 [STATEMENT_CONTINUE]    = sizeof(statement_base_t),
 285                 [STATEMENT_BREAK]       = sizeof(statement_base_t),
 286                 [STATEMENT_GOTO]        = sizeof(goto_statement_t),
 287                 [STATEMENT_LABEL]       = sizeof(label_statement_t),
 288                 [STATEMENT_CASE_LABEL]  = sizeof(case_label_statement_t),
 289                 [STATEMENT_WHILE]       = sizeof(while_statement_t),
 290                 [STATEMENT_DO_WHILE]    = sizeof(do_while_statement_t),
 291                 [STATEMENT_FOR]         = sizeof(for_statement_t),
 292                 [STATEMENT_ASM]         = sizeof(asm_statement_t),
 293                 [STATEMENT_MS_TRY]      = sizeof(ms_try_statement_t),
 294                 [STATEMENT_LEAVE]       = sizeof(leave_statement_t)
 295         };
 296         assert(kind < lengthof(sizes));
 297         assert(sizes[kind] != 0);
 298         return sizes[kind];
 299 }
 300
 301 /**
 302  * Returns the size of an expression node.
 303  *
 304  * @param kind  the expression kind
 305  */
 306 static size_t get_expression_struct_size(expression_kind_t kind)
 307 {
 308         static const size_t sizes[] = {
 309                 [EXPR_INVALID]                    = sizeof(expression_base_t),
 310                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 311                 [EXPR_REFERENCE_ENUM_VALUE]       = sizeof(reference_expression_t),
 312                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 313                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 314                 [EXPR_LITERAL_INTEGER_OCTAL]      = sizeof(literal_expression_t),
 315                 [EXPR_LITERAL_INTEGER_HEXADECIMAL]= sizeof(literal_expression_t),
 316                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 317                 [EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL] = sizeof(literal_expression_t),
 318                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 319                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 320                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 321                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 322                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 323                 [EXPR_CALL]                       = sizeof(call_expression_t),
 324                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 325                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 326                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 327                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 328                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 329                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 330                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 331                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 332                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 333                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 334                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 335                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 336                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 337                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 338                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 339                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 340                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 341         };
 342         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 343                 return sizes[EXPR_UNARY_FIRST];
 344         }
 345         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 346                 return sizes[EXPR_BINARY_FIRST];
 347         }
 348         assert(kind < lengthof(sizes));
 349         assert(sizes[kind] != 0);
 350         return sizes[kind];
 351 }
 352
 353 /**
 354  * Allocate a statement node of given kind and initialize all
 355  * fields with zero. Sets its source position to the position
 356  * of the current token.
 357  */
 358 static statement_t *allocate_statement_zero(statement_kind_t kind)
 359 {
 360         size_t       size = get_statement_struct_size(kind);
 361         statement_t *res  = allocate_ast_zero(size);
 362
 363         res->base.kind            = kind;
 364         res->base.parent          = current_parent;
 365         res->base.source_position = token.source_position;
 366         return res;
 367 }
 368
 369 /**
 370  * Allocate an expression node of given kind and initialize all
 371  * fields with zero.
 372  *
 373  * @param kind  the kind of the expression to allocate
 374  */
 375 static expression_t *allocate_expression_zero(expression_kind_t kind)
 376 {
 377         size_t        size = get_expression_struct_size(kind);
 378         expression_t *res  = allocate_ast_zero(size);
 379
 380         res->base.kind            = kind;
 381         res->base.type            = type_error_type;
 382         res->base.source_position = token.source_position;
 383         return res;
 384 }
 385
 386 /**
 387  * Creates a new invalid expression at the source position
 388  * of the current token.
 389  */
 390 static expression_t *create_invalid_expression(void)
 391 {
 392         return allocate_expression_zero(EXPR_INVALID);
 393 }
 394
 395 /**
 396  * Creates a new invalid statement.
 397  */
 398 static statement_t *create_invalid_statement(void)
 399 {
 400         return allocate_statement_zero(STATEMENT_INVALID);
 401 }
 402
 403 /**
 404  * Allocate a new empty statement.
 405  */
 406 static statement_t *create_empty_statement(void)
 407 {
 408         return allocate_statement_zero(STATEMENT_EMPTY);
 409 }
 410
 411 static function_parameter_t *allocate_parameter(type_t *const type)
 412 {
 413         function_parameter_t *const param
 414                 = obstack_alloc(type_obst, sizeof(*param));
 415         memset(param, 0, sizeof(*param));
 416         param->type = type;
 417         return param;
 418 }
 419
 420 /**
 421  * Returns the size of an initializer node.
 422  *
 423  * @param kind  the initializer kind
 424  */
 425 static size_t get_initializer_size(initializer_kind_t kind)
 426 {
 427         static const size_t sizes[] = {
 428                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 429                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 430                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 431                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 432                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 433         };
 434         assert(kind < lengthof(sizes));
 435         assert(sizes[kind] != 0);
 436         return sizes[kind];
 437 }
 438
 439 /**
 440  * Allocate an initializer node of given kind and initialize all
 441  * fields with zero.
 442  */
 443 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 444 {
 445         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 446         result->kind          = kind;
 447
 448         return result;
 449 }
 450
 451 /**
 452  * Returns the index of the top element of the environment stack.
 453  */
 454 static size_t environment_top(void)
 455 {
 456         return ARR_LEN(environment_stack);
 457 }
 458
 459 /**
 460  * Returns the index of the top element of the global label stack.
 461  */
 462 static size_t label_top(void)
 463 {
 464         return ARR_LEN(label_stack);
 465 }
 466
 467 /**
 468  * Return the next token.
 469  */
 470 static inline void next_token(void)
 471 {
 472         token                              = lookahead_buffer[lookahead_bufpos];
 473         lookahead_buffer[lookahead_bufpos] = lexer_token;
 474         lexer_next_token();
 475
 476         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 477
 478 #ifdef PRINT_TOKENS
 479         print_token(stderr, &token);
 480         fprintf(stderr, "\n");
 481 #endif
 482 }
 483
 484 static inline bool next_if(int const type)
 485 {
 486         if (token.type == type) {
 487                 next_token();
 488                 return true;
 489         } else {
 490                 return false;
 491         }
 492 }
 493
 494 /**
 495  * Return the next token with a given lookahead.
 496  */
 497 static inline const token_t *look_ahead(size_t num)
 498 {
 499         assert(0 < num && num <= MAX_LOOKAHEAD);
 500         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 501         return &lookahead_buffer[pos];
 502 }
 503
 504 /**
 505  * Adds a token type to the token type anchor set (a multi-set).
 506  */
 507 static void add_anchor_token(int token_type)
 508 {
 509         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 510         ++token_anchor_set[token_type];
 511 }
 512
 513 /**
 514  * Set the number of tokens types of the given type
 515  * to zero and return the old count.
 516  */
 517 static int save_and_reset_anchor_state(int token_type)
 518 {
 519         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 520         int count = token_anchor_set[token_type];
 521         token_anchor_set[token_type] = 0;
 522         return count;
 523 }
 524
 525 /**
 526  * Restore the number of token types to the given count.
 527  */
 528 static void restore_anchor_state(int token_type, int count)
 529 {
 530         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 531         token_anchor_set[token_type] = count;
 532 }
 533
 534 /**
 535  * Remove a token type from the token type anchor set (a multi-set).
 536  */
 537 static void rem_anchor_token(int token_type)
 538 {
 539         assert(0 <= token_type && token_type < T_LAST_TOKEN);
 540         assert(token_anchor_set[token_type] != 0);
 541         --token_anchor_set[token_type];
 542 }
 543
 544 /**
 545  * Return true if the token type of the current token is
 546  * in the anchor set.
 547  */
 548 static bool at_anchor(void)
 549 {
 550         if (token.type < 0)
 551                 return false;
 552         return token_anchor_set[token.type];
 553 }
 554
 555 /**
 556  * Eat tokens until a matching token type is found.
 557  */
 558 static void eat_until_matching_token(int type)
 559 {
 560         int end_token;
 561         switch (type) {
 562                 case '(': end_token = ')';  break;
 563                 case '{': end_token = '}';  break;
 564                 case '[': end_token = ']';  break;
 565                 default:  end_token = type; break;
 566         }
 567
 568         unsigned parenthesis_count = 0;
 569         unsigned brace_count       = 0;
 570         unsigned bracket_count     = 0;
 571         while (token.type        != end_token ||
 572                parenthesis_count != 0         ||
 573                brace_count       != 0         ||
 574                bracket_count     != 0) {
 575                 switch (token.type) {
 576                 case T_EOF: return;
 577                 case '(': ++parenthesis_count; break;
 578                 case '{': ++brace_count;       break;
 579                 case '[': ++bracket_count;     break;
 580
 581                 case ')':
 582                         if (parenthesis_count > 0)
 583                                 --parenthesis_count;
 584                         goto check_stop;
 585
 586                 case '}':
 587                         if (brace_count > 0)
 588                                 --brace_count;
 589                         goto check_stop;
 590
 591                 case ']':
 592                         if (bracket_count > 0)
 593                                 --bracket_count;
 594 check_stop:
 595                         if (token.type        == end_token &&
 596                             parenthesis_count == 0         &&
 597                             brace_count       == 0         &&
 598                             bracket_count     == 0)
 599                                 return;
 600                         break;
 601
 602                 default:
 603                         break;
 604                 }
 605                 next_token();
 606         }
 607 }
 608
 609 /**
 610  * Eat input tokens until an anchor is found.
 611  */
 612 static void eat_until_anchor(void)
 613 {
 614         while (token_anchor_set[token.type] == 0) {
 615                 if (token.type == '(' || token.type == '{' || token.type == '[')
 616                         eat_until_matching_token(token.type);
 617                 next_token();
 618         }
 619 }
 620
 621 /**
 622  * Eat a whole block from input tokens.
 623  */
 624 static void eat_block(void)
 625 {
 626         eat_until_matching_token('{');
 627         next_if('}');
 628 }
 629
 630 #define eat(token_type) (assert(token.type == (token_type)), next_token())
 631
 632 /**
 633  * Report a parse error because an expected token was not found.
 634  */
 635 static
 636 #if defined __GNUC__ && __GNUC__ >= 4
 637 __attribute__((sentinel))
 638 #endif
 639 void parse_error_expected(const char *message, ...)
 640 {
 641         if (message != NULL) {
 642                 errorf(HERE, "%s", message);
 643         }
 644         va_list ap;
 645         va_start(ap, message);
 646         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 647         va_end(ap);
 648 }
 649
 650 /**
 651  * Report an incompatible type.
 652  */
 653 static void type_error_incompatible(const char *msg,
 654                 const source_position_t *source_position, type_t *type1, type_t *type2)
 655 {
 656         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 657                msg, type1, type2);
 658 }
 659
 660 /**
 661  * Expect the current token is the expected token.
 662  * If not, generate an error, eat the current statement,
 663  * and goto the error_label label.
 664  */
 665 #define expect(expected, error_label)                     \
 666         do {                                                  \
 667                 if (UNLIKELY(token.type != (expected))) {         \
 668                         parse_error_expected(NULL, (expected), NULL); \
 669                         add_anchor_token(expected);                   \
 670                         eat_until_anchor();                           \
 671                         next_if((expected));                          \
 672                         rem_anchor_token(expected);                   \
 673                         goto error_label;                             \
 674                 }                                                 \
 675                 next_token();                                     \
 676         } while (0)
 677
 678 /**
 679  * Push a given scope on the scope stack and make it the
 680  * current scope
 681  */
 682 static scope_t *scope_push(scope_t *new_scope)
 683 {
 684         if (current_scope != NULL) {
 685                 new_scope->depth = current_scope->depth + 1;
 686         }
 687
 688         scope_t *old_scope = current_scope;
 689         current_scope      = new_scope;
 690         return old_scope;
 691 }
 692
 693 /**
 694  * Pop the current scope from the scope stack.
 695  */
 696 static void scope_pop(scope_t *old_scope)
 697 {
 698         current_scope = old_scope;
 699 }
 700
 701 /**
 702  * Search an entity by its symbol in a given namespace.
 703  */
 704 static entity_t *get_entity(const symbol_t *const symbol,
 705                             namespace_tag_t namespc)
 706 {
 707         assert(namespc != NAMESPACE_INVALID);
 708         entity_t *entity = symbol->entity;
 709         for (; entity != NULL; entity = entity->base.symbol_next) {
 710                 if (entity->base.namespc == namespc)
 711                         return entity;
 712         }
 713
 714         return NULL;
 715 }
 716
 717 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 718  * possible. */
 719 static entity_t *get_tag(symbol_t const *const symbol,
 720                          entity_kind_tag_t const kind)
 721 {
 722         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 723         if (entity != NULL && entity->kind != kind) {
 724                 errorf(HERE,
 725                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 726                                 symbol, &entity->base.source_position);
 727                 entity = NULL;
 728         }
 729         return entity;
 730 }
 731
 732 /**
 733  * pushs an entity on the environment stack and links the corresponding symbol
 734  * it.
 735  */
 736 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 737 {
 738         symbol_t           *symbol  = entity->base.symbol;
 739         entity_namespace_t  namespc = entity->base.namespc;
 740         assert(namespc != NAMESPACE_INVALID);
 741
 742         /* replace/add entity into entity list of the symbol */
 743         entity_t **anchor;
 744         entity_t  *iter;
 745         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 746                 iter = *anchor;
 747                 if (iter == NULL)
 748                         break;
 749
 750                 /* replace an entry? */
 751                 if (iter->base.namespc == namespc) {
 752                         entity->base.symbol_next = iter->base.symbol_next;
 753                         break;
 754                 }
 755         }
 756         *anchor = entity;
 757
 758         /* remember old declaration */
 759         stack_entry_t entry;
 760         entry.symbol     = symbol;
 761         entry.old_entity = iter;
 762         entry.namespc    = namespc;
 763         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 764 }
 765
 766 /**
 767  * Push an entity on the environment stack.
 768  */
 769 static void environment_push(entity_t *entity)
 770 {
 771         assert(entity->base.source_position.input_name != NULL);
 772         assert(entity->base.parent_scope != NULL);
 773         stack_push(&environment_stack, entity);
 774 }
 775
 776 /**
 777  * Push a declaration on the global label stack.
 778  *
 779  * @param declaration  the declaration
 780  */
 781 static void label_push(entity_t *label)
 782 {
 783         /* we abuse the parameters scope as parent for the labels */
 784         label->base.parent_scope = &current_function->parameters;
 785         stack_push(&label_stack, label);
 786 }
 787
 788 /**
 789  * pops symbols from the environment stack until @p new_top is the top element
 790  */
 791 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 792 {
 793         stack_entry_t *stack = *stack_ptr;
 794         size_t         top   = ARR_LEN(stack);
 795         size_t         i;
 796
 797         assert(new_top <= top);
 798         if (new_top == top)
 799                 return;
 800
 801         for (i = top; i > new_top; --i) {
 802                 stack_entry_t *entry = &stack[i - 1];
 803
 804                 entity_t           *old_entity = entry->old_entity;
 805                 symbol_t           *symbol     = entry->symbol;
 806                 entity_namespace_t  namespc    = entry->namespc;
 807
 808                 /* replace with old_entity/remove */
 809                 entity_t **anchor;
 810                 entity_t  *iter;
 811                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 812                         iter = *anchor;
 813                         assert(iter != NULL);
 814                         /* replace an entry? */
 815                         if (iter->base.namespc == namespc)
 816                                 break;
 817                 }
 818
 819                 /* restore definition from outer scopes (if there was one) */
 820                 if (old_entity != NULL) {
 821                         old_entity->base.symbol_next = iter->base.symbol_next;
 822                         *anchor                      = old_entity;
 823                 } else {
 824                         /* remove entry from list */
 825                         *anchor = iter->base.symbol_next;
 826                 }
 827         }
 828
 829         ARR_SHRINKLEN(*stack_ptr, new_top);
 830 }
 831
 832 /**
 833  * Pop all entries from the environment stack until the new_top
 834  * is reached.
 835  *
 836  * @param new_top  the new stack top
 837  */
 838 static void environment_pop_to(size_t new_top)
 839 {
 840         stack_pop_to(&environment_stack, new_top);
 841 }
 842
 843 /**
 844  * Pop all entries from the global label stack until the new_top
 845  * is reached.
 846  *
 847  * @param new_top  the new stack top
 848  */
 849 static void label_pop_to(size_t new_top)
 850 {
 851         stack_pop_to(&label_stack, new_top);
 852 }
 853
 854 static int get_akind_rank(atomic_type_kind_t akind)
 855 {
 856         return (int) akind;
 857 }
 858
 859 /**
 860  * Return the type rank for an atomic type.
 861  */
 862 static int get_rank(const type_t *type)
 863 {
 864         assert(!is_typeref(type));
 865         if (type->kind == TYPE_ENUM)
 866                 return get_akind_rank(type->enumt.akind);
 867
 868         assert(type->kind == TYPE_ATOMIC);
 869         return get_akind_rank(type->atomic.akind);
 870 }
 871
 872 /**
 873  * §6.3.1.1:2  Do integer promotion for a given type.
 874  *
 875  * @param type  the type to promote
 876  * @return the promoted type
 877  */
 878 static type_t *promote_integer(type_t *type)
 879 {
 880         if (type->kind == TYPE_BITFIELD)
 881                 type = type->bitfield.base_type;
 882
 883         if (get_rank(type) < get_akind_rank(ATOMIC_TYPE_INT))
 884                 type = type_int;
 885
 886         return type;
 887 }
 888
 889 /**
 890  * Create a cast expression.
 891  *
 892  * @param expression  the expression to cast
 893  * @param dest_type   the destination type
 894  */
 895 static expression_t *create_cast_expression(expression_t *expression,
 896                                             type_t *dest_type)
 897 {
 898         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST_IMPLICIT);
 899
 900         cast->unary.value = expression;
 901         cast->base.type   = dest_type;
 902
 903         return cast;
 904 }
 905
 906 /**
 907  * Check if a given expression represents a null pointer constant.
 908  *
 909  * @param expression  the expression to check
 910  */
 911 static bool is_null_pointer_constant(const expression_t *expression)
 912 {
 913         /* skip void* cast */
 914         if (expression->kind == EXPR_UNARY_CAST ||
 915                         expression->kind == EXPR_UNARY_CAST_IMPLICIT) {
 916                 type_t *const type = skip_typeref(expression->base.type);
 917                 if (types_compatible(type, type_void_ptr))
 918                         expression = expression->unary.value;
 919         }
 920
 921         type_t *const type = skip_typeref(expression->base.type);
 922         if (!is_type_integer(type))
 923                 return false;
 924         switch (is_constant_expression(expression)) {
 925                 case EXPR_CLASS_ERROR:    return true;
 926                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 927                 default:                  return false;
 928         }
 929 }
 930
 931 /**
 932  * Create an implicit cast expression.
 933  *
 934  * @param expression  the expression to cast
 935  * @param dest_type   the destination type
 936  */
 937 static expression_t *create_implicit_cast(expression_t *expression,
 938                                           type_t *dest_type)
 939 {
 940         type_t *const source_type = expression->base.type;
 941
 942         if (source_type == dest_type)
 943                 return expression;
 944
 945         return create_cast_expression(expression, dest_type);
 946 }
 947
 948 typedef enum assign_error_t {
 949         ASSIGN_SUCCESS,
 950         ASSIGN_ERROR_INCOMPATIBLE,
 951         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 952         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 953         ASSIGN_WARNING_POINTER_FROM_INT,
 954         ASSIGN_WARNING_INT_FROM_POINTER
 955 } assign_error_t;
 956
 957 static void report_assign_error(assign_error_t error, type_t *orig_type_left,
 958                                 const expression_t *const right,
 959                                 const char *context,
 960                                 const source_position_t *source_position)
 961 {
 962         type_t *const orig_type_right = right->base.type;
 963         type_t *const type_left       = skip_typeref(orig_type_left);
 964         type_t *const type_right      = skip_typeref(orig_type_right);
 965
 966         switch (error) {
 967         case ASSIGN_SUCCESS:
 968                 return;
 969         case ASSIGN_ERROR_INCOMPATIBLE:
 970                 errorf(source_position,
 971                        "destination type '%T' in %s is incompatible with type '%T'",
 972                        orig_type_left, context, orig_type_right);
 973                 return;
 974
 975         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 976                 if (warning.other) {
 977                         type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 978                         type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 979
 980                         /* the left type has all qualifiers from the right type */
 981                         unsigned missing_qualifiers
 982                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 983                         warningf(source_position,
 984                                         "destination type '%T' in %s from type '%T' lacks qualifiers '%Q' in pointer target type",
 985                                         orig_type_left, context, orig_type_right, missing_qualifiers);
 986                 }
 987                 return;
 988         }
 989
 990         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 991                 if (warning.other) {
 992                         warningf(source_position,
 993                                         "destination type '%T' in %s is incompatible with '%E' of type '%T'",
 994                                         orig_type_left, context, right, orig_type_right);
 995                 }
 996                 return;
 997
 998         case ASSIGN_WARNING_POINTER_FROM_INT:
 999                 if (warning.other) {
1000                         warningf(source_position,
1001                                         "%s makes pointer '%T' from integer '%T' without a cast",
1002                                         context, orig_type_left, orig_type_right);
1003                 }
1004                 return;
1005
1006         case ASSIGN_WARNING_INT_FROM_POINTER:
1007                 if (warning.other) {
1008                         warningf(source_position,
1009                                         "%s makes integer '%T' from pointer '%T' without a cast",
1010                                         context, orig_type_left, orig_type_right);
1011                 }
1012                 return;
1013
1014         default:
1015                 panic("invalid error value");
1016         }
1017 }
1018
1019 /** Implements the rules from §6.5.16.1 */
1020 static assign_error_t semantic_assign(type_t *orig_type_left,
1021                                       const expression_t *const right)
1022 {
1023         type_t *const orig_type_right = right->base.type;
1024         type_t *const type_left       = skip_typeref(orig_type_left);
1025         type_t *const type_right      = skip_typeref(orig_type_right);
1026
1027         if (is_type_pointer(type_left)) {
1028                 if (is_null_pointer_constant(right)) {
1029                         return ASSIGN_SUCCESS;
1030                 } else if (is_type_pointer(type_right)) {
1031                         type_t *points_to_left
1032                                 = skip_typeref(type_left->pointer.points_to);
1033                         type_t *points_to_right
1034                                 = skip_typeref(type_right->pointer.points_to);
1035                         assign_error_t res = ASSIGN_SUCCESS;
1036
1037                         /* the left type has all qualifiers from the right type */
1038                         unsigned missing_qualifiers
1039                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
1040                         if (missing_qualifiers != 0) {
1041                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
1042                         }
1043
1044                         points_to_left  = get_unqualified_type(points_to_left);
1045                         points_to_right = get_unqualified_type(points_to_right);
1046
1047                         if (is_type_atomic(points_to_left, ATOMIC_TYPE_VOID))
1048                                 return res;
1049
1050                         if (is_type_atomic(points_to_right, ATOMIC_TYPE_VOID)) {
1051                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
1052                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
1053                         }
1054
1055                         if (!types_compatible(points_to_left, points_to_right)) {
1056                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1057                         }
1058
1059                         return res;
1060                 } else if (is_type_integer(type_right)) {
1061                         return ASSIGN_WARNING_POINTER_FROM_INT;
1062                 }
1063         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1064                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1065                                 && is_type_pointer(type_right))) {
1066                 return ASSIGN_SUCCESS;
1067         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1068                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1069                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1070                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1071                         return ASSIGN_SUCCESS;
1072                 }
1073         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1074                 return ASSIGN_WARNING_INT_FROM_POINTER;
1075         }
1076
1077         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1078                 return ASSIGN_SUCCESS;
1079
1080         return ASSIGN_ERROR_INCOMPATIBLE;
1081 }
1082
1083 static expression_t *parse_constant_expression(void)
1084 {
1085         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1086
1087         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1088                 errorf(&result->base.source_position,
1089                        "expression '%E' is not constant", result);
1090         }
1091
1092         return result;
1093 }
1094
1095 static expression_t *parse_assignment_expression(void)
1096 {
1097         return parse_subexpression(PREC_ASSIGNMENT);
1098 }
1099
1100 static void warn_string_concat(const source_position_t *pos)
1101 {
1102         if (warning.traditional) {
1103                 warningf(pos, "traditional C rejects string constant concatenation");
1104         }
1105 }
1106
1107 static string_t parse_string_literals(void)
1108 {
1109         assert(token.type == T_STRING_LITERAL);
1110         string_t result = token.literal;
1111
1112         next_token();
1113
1114         while (token.type == T_STRING_LITERAL) {
1115                 warn_string_concat(&token.source_position);
1116                 result = concat_strings(&result, &token.literal);
1117                 next_token();
1118         }
1119
1120         return result;
1121 }
1122
1123 /**
1124  * compare two string, ignoring double underscores on the second.
1125  */
1126 static int strcmp_underscore(const char *s1, const char *s2)
1127 {
1128         if (s2[0] == '_' && s2[1] == '_') {
1129                 size_t len2 = strlen(s2);
1130                 size_t len1 = strlen(s1);
1131                 if (len1 == len2-4 && s2[len2-2] == '_' && s2[len2-1] == '_') {
1132                         return strncmp(s1, s2+2, len2-4);
1133                 }
1134         }
1135
1136         return strcmp(s1, s2);
1137 }
1138
1139 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1140 {
1141         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1142         attribute->kind        = kind;
1143         return attribute;
1144 }
1145
1146 /**
1147  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1148  *
1149  *  attribute:
1150  *    __attribute__ ( ( attribute-list ) )
1151  *
1152  *  attribute-list:
1153  *    attrib
1154  *    attribute_list , attrib
1155  *
1156  *  attrib:
1157  *    empty
1158  *    any-word
1159  *    any-word ( identifier )
1160  *    any-word ( identifier , nonempty-expr-list )
1161  *    any-word ( expr-list )
1162  *
1163  *  where the "identifier" must not be declared as a type, and
1164  *  "any-word" may be any identifier (including one declared as a
1165  *  type), a reserved word storage class specifier, type specifier or
1166  *  type qualifier.  ??? This still leaves out most reserved keywords
1167  *  (following the old parser), shouldn't we include them, and why not
1168  *  allow identifiers declared as types to start the arguments?
1169  *
1170  *  Matze: this all looks confusing and little systematic, so we're even less
1171  *  strict and parse any list of things which are identifiers or
1172  *  (assignment-)expressions.
1173  */
1174 static attribute_argument_t *parse_attribute_arguments(void)
1175 {
1176         attribute_argument_t  *first  = NULL;
1177         attribute_argument_t **anchor = &first;
1178         if (token.type != ')') do {
1179                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1180
1181                 /* is it an identifier */
1182                 if (token.type == T_IDENTIFIER
1183                                 && (look_ahead(1)->type == ',' || look_ahead(1)->type == ')')) {
1184                         symbol_t *symbol   = token.symbol;
1185                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1186                         argument->v.symbol = symbol;
1187                         next_token();
1188                 } else {
1189                         /* must be an expression */
1190                         expression_t *expression = parse_assignment_expression();
1191
1192                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1193                         argument->v.expression = expression;
1194                 }
1195
1196                 /* append argument */
1197                 *anchor = argument;
1198                 anchor  = &argument->next;
1199         } while (next_if(','));
1200         expect(')', end_error);
1201
1202         return first;
1203
1204 end_error:
1205         /* TODO... */
1206         return first;
1207 }
1208
1209 static attribute_t *parse_attribute_asm(void)
1210 {
1211         eat(T_asm);
1212
1213         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1214
1215         expect('(', end_error);
1216         attribute->a.arguments = parse_attribute_arguments();
1217         return attribute;
1218
1219 end_error:
1220         return NULL;
1221 }
1222
1223 static symbol_t *get_symbol_from_token(void)
1224 {
1225         switch(token.type) {
1226         case T_IDENTIFIER:
1227                 return token.symbol;
1228         case T_auto:
1229         case T_char:
1230         case T_double:
1231         case T_enum:
1232         case T_extern:
1233         case T_float:
1234         case T_int:
1235         case T_long:
1236         case T_register:
1237         case T_short:
1238         case T_static:
1239         case T_struct:
1240         case T_union:
1241         case T_unsigned:
1242         case T_void:
1243         case T_bool:
1244         case T__Bool:
1245         case T_class:
1246         case T_explicit:
1247         case T_export:
1248         case T_wchar_t:
1249         case T_const:
1250         case T_signed:
1251         case T___real__:
1252         case T___imag__:
1253         case T_restrict:
1254         case T_volatile:
1255         case T_inline:
1256                 /* maybe we need more tokens ... add them on demand */
1257                 return get_token_symbol(&token);
1258         default:
1259                 return NULL;
1260         }
1261 }
1262
1263 static attribute_t *parse_attribute_gnu_single(void)
1264 {
1265         /* parse "any-word" */
1266         symbol_t *symbol = get_symbol_from_token();
1267         if (symbol == NULL) {
1268                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1269                 return NULL;
1270         }
1271
1272         const char *name = symbol->string;
1273         next_token();
1274
1275         attribute_kind_t kind;
1276         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1277                 if (kind > ATTRIBUTE_GNU_LAST) {
1278                         if (warning.attribute) {
1279                                 warningf(HERE, "unknown attribute '%s' ignored", name);
1280                         }
1281                         /* TODO: we should still save the attribute in the list... */
1282                         kind = ATTRIBUTE_UNKNOWN;
1283                         break;
1284                 }
1285
1286                 const char *attribute_name = get_attribute_name(kind);
1287                 if (attribute_name != NULL
1288                                 && strcmp_underscore(attribute_name, name) == 0)
1289                         break;
1290         }
1291
1292         attribute_t *attribute = allocate_attribute_zero(kind);
1293
1294         /* parse arguments */
1295         if (next_if('('))
1296                 attribute->a.arguments = parse_attribute_arguments();
1297
1298         return attribute;
1299 }
1300
1301 static attribute_t *parse_attribute_gnu(void)
1302 {
1303         attribute_t  *first  = NULL;
1304         attribute_t **anchor = &first;
1305
1306         eat(T___attribute__);
1307         expect('(', end_error);
1308         expect('(', end_error);
1309
1310         if (token.type != ')') do {
1311                 attribute_t *attribute = parse_attribute_gnu_single();
1312                 if (attribute == NULL)
1313                         goto end_error;
1314
1315                 *anchor = attribute;
1316                 anchor  = &attribute->next;
1317         } while (next_if(','));
1318         expect(')', end_error);
1319         expect(')', end_error);
1320
1321 end_error:
1322         return first;
1323 }
1324
1325 /** Parse attributes. */
1326 static attribute_t *parse_attributes(attribute_t *first)
1327 {
1328         attribute_t **anchor = &first;
1329         for (;;) {
1330                 while (*anchor != NULL)
1331                         anchor = &(*anchor)->next;
1332
1333                 attribute_t *attribute;
1334                 switch (token.type) {
1335                 case T___attribute__:
1336                         attribute = parse_attribute_gnu();
1337                         if (attribute == NULL)
1338                                 continue;
1339                         break;
1340
1341                 case T_asm:
1342                         attribute = parse_attribute_asm();
1343                         break;
1344
1345                 case T_cdecl:
1346                         next_token();
1347                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1348                         break;
1349
1350                 case T__fastcall:
1351                         next_token();
1352                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1353                         break;
1354
1355                 case T__forceinline:
1356                         next_token();
1357                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1358                         break;
1359
1360                 case T__stdcall:
1361                         next_token();
1362                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1363                         break;
1364
1365                 case T___thiscall:
1366                         next_token();
1367                         /* TODO record modifier */
1368                         if (warning.other)
1369                                 warningf(HERE, "Ignoring declaration modifier %K", &token);
1370                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1371                         break;
1372
1373                 default:
1374                         return first;
1375                 }
1376
1377                 *anchor = attribute;
1378                 anchor  = &attribute->next;
1379         }
1380 }
1381
1382 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1383
1384 static entity_t *determine_lhs_ent(expression_t *const expr,
1385                                    entity_t *lhs_ent)
1386 {
1387         switch (expr->kind) {
1388                 case EXPR_REFERENCE: {
1389                         entity_t *const entity = expr->reference.entity;
1390                         /* we should only find variables as lvalues... */
1391                         if (entity->base.kind != ENTITY_VARIABLE
1392                                         && entity->base.kind != ENTITY_PARAMETER)
1393                                 return NULL;
1394
1395                         return entity;
1396                 }
1397
1398                 case EXPR_ARRAY_ACCESS: {
1399                         expression_t *const ref = expr->array_access.array_ref;
1400                         entity_t     *      ent = NULL;
1401                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1402                                 ent     = determine_lhs_ent(ref, lhs_ent);
1403                                 lhs_ent = ent;
1404                         } else {
1405                                 mark_vars_read(expr->select.compound, lhs_ent);
1406                         }
1407                         mark_vars_read(expr->array_access.index, lhs_ent);
1408                         return ent;
1409                 }
1410
1411                 case EXPR_SELECT: {
1412                         if (is_type_compound(skip_typeref(expr->base.type))) {
1413                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1414                         } else {
1415                                 mark_vars_read(expr->select.compound, lhs_ent);
1416                                 return NULL;
1417                         }
1418                 }
1419
1420                 case EXPR_UNARY_DEREFERENCE: {
1421                         expression_t *const val = expr->unary.value;
1422                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1423                                 /* *&x is a NOP */
1424                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1425                         } else {
1426                                 mark_vars_read(val, NULL);
1427                                 return NULL;
1428                         }
1429                 }
1430
1431                 default:
1432                         mark_vars_read(expr, NULL);
1433                         return NULL;
1434         }
1435 }
1436
1437 #define ENT_ANY ((entity_t*)-1)
1438
1439 /**
1440  * Mark declarations, which are read.  This is used to detect variables, which
1441  * are never read.
1442  * Example:
1443  * x = x + 1;
1444  *   x is not marked as "read", because it is only read to calculate its own new
1445  *   value.
1446  *
1447  * x += y; y += x;
1448  *   x and y are not detected as "not read", because multiple variables are
1449  *   involved.
1450  */
1451 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1452 {
1453         switch (expr->kind) {
1454                 case EXPR_REFERENCE: {
1455                         entity_t *const entity = expr->reference.entity;
1456                         if (entity->kind != ENTITY_VARIABLE
1457                                         && entity->kind != ENTITY_PARAMETER)
1458                                 return;
1459
1460                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1461                                 if (entity->kind == ENTITY_VARIABLE) {
1462                                         entity->variable.read = true;
1463                                 } else {
1464                                         entity->parameter.read = true;
1465                                 }
1466                         }
1467                         return;
1468                 }
1469
1470                 case EXPR_CALL:
1471                         // TODO respect pure/const
1472                         mark_vars_read(expr->call.function, NULL);
1473                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1474                                 mark_vars_read(arg->expression, NULL);
1475                         }
1476                         return;
1477
1478                 case EXPR_CONDITIONAL:
1479                         // TODO lhs_decl should depend on whether true/false have an effect
1480                         mark_vars_read(expr->conditional.condition, NULL);
1481                         if (expr->conditional.true_expression != NULL)
1482                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1483                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1484                         return;
1485
1486                 case EXPR_SELECT:
1487                         if (lhs_ent == ENT_ANY
1488                                         && !is_type_compound(skip_typeref(expr->base.type)))
1489                                 lhs_ent = NULL;
1490                         mark_vars_read(expr->select.compound, lhs_ent);
1491                         return;
1492
1493                 case EXPR_ARRAY_ACCESS: {
1494                         expression_t *const ref = expr->array_access.array_ref;
1495                         mark_vars_read(ref, lhs_ent);
1496                         lhs_ent = determine_lhs_ent(ref, lhs_ent);
1497                         mark_vars_read(expr->array_access.index, lhs_ent);
1498                         return;
1499                 }
1500
1501                 case EXPR_VA_ARG:
1502                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1503                         return;
1504
1505                 case EXPR_VA_COPY:
1506                         mark_vars_read(expr->va_copye.src, lhs_ent);
1507                         return;
1508
1509                 case EXPR_UNARY_CAST:
1510                         /* Special case: Use void cast to mark a variable as "read" */
1511                         if (is_type_atomic(skip_typeref(expr->base.type), ATOMIC_TYPE_VOID))
1512                                 lhs_ent = NULL;
1513                         goto unary;
1514
1515
1516                 case EXPR_UNARY_THROW:
1517                         if (expr->unary.value == NULL)
1518                                 return;
1519                         /* FALLTHROUGH */
1520                 case EXPR_UNARY_DEREFERENCE:
1521                 case EXPR_UNARY_DELETE:
1522                 case EXPR_UNARY_DELETE_ARRAY:
1523                         if (lhs_ent == ENT_ANY)
1524                                 lhs_ent = NULL;
1525                         goto unary;
1526
1527                 case EXPR_UNARY_NEGATE:
1528                 case EXPR_UNARY_PLUS:
1529                 case EXPR_UNARY_BITWISE_NEGATE:
1530                 case EXPR_UNARY_NOT:
1531                 case EXPR_UNARY_TAKE_ADDRESS:
1532                 case EXPR_UNARY_POSTFIX_INCREMENT:
1533                 case EXPR_UNARY_POSTFIX_DECREMENT:
1534                 case EXPR_UNARY_PREFIX_INCREMENT:
1535                 case EXPR_UNARY_PREFIX_DECREMENT:
1536                 case EXPR_UNARY_CAST_IMPLICIT:
1537                 case EXPR_UNARY_ASSUME:
1538 unary:
1539                         mark_vars_read(expr->unary.value, lhs_ent);
1540                         return;
1541
1542                 case EXPR_BINARY_ADD:
1543                 case EXPR_BINARY_SUB:
1544                 case EXPR_BINARY_MUL:
1545                 case EXPR_BINARY_DIV:
1546                 case EXPR_BINARY_MOD:
1547                 case EXPR_BINARY_EQUAL:
1548                 case EXPR_BINARY_NOTEQUAL:
1549                 case EXPR_BINARY_LESS:
1550                 case EXPR_BINARY_LESSEQUAL:
1551                 case EXPR_BINARY_GREATER:
1552                 case EXPR_BINARY_GREATEREQUAL:
1553                 case EXPR_BINARY_BITWISE_AND:
1554                 case EXPR_BINARY_BITWISE_OR:
1555                 case EXPR_BINARY_BITWISE_XOR:
1556                 case EXPR_BINARY_LOGICAL_AND:
1557                 case EXPR_BINARY_LOGICAL_OR:
1558                 case EXPR_BINARY_SHIFTLEFT:
1559                 case EXPR_BINARY_SHIFTRIGHT:
1560                 case EXPR_BINARY_COMMA:
1561                 case EXPR_BINARY_ISGREATER:
1562                 case EXPR_BINARY_ISGREATEREQUAL:
1563                 case EXPR_BINARY_ISLESS:
1564                 case EXPR_BINARY_ISLESSEQUAL:
1565                 case EXPR_BINARY_ISLESSGREATER:
1566                 case EXPR_BINARY_ISUNORDERED:
1567                         mark_vars_read(expr->binary.left,  lhs_ent);
1568                         mark_vars_read(expr->binary.right, lhs_ent);
1569                         return;
1570
1571                 case EXPR_BINARY_ASSIGN:
1572                 case EXPR_BINARY_MUL_ASSIGN:
1573                 case EXPR_BINARY_DIV_ASSIGN:
1574                 case EXPR_BINARY_MOD_ASSIGN:
1575                 case EXPR_BINARY_ADD_ASSIGN:
1576                 case EXPR_BINARY_SUB_ASSIGN:
1577                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1578                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1579                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1580                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1581                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1582                         if (lhs_ent == ENT_ANY)
1583                                 lhs_ent = NULL;
1584                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1585                         mark_vars_read(expr->binary.right, lhs_ent);
1586                         return;
1587                 }
1588
1589                 case EXPR_VA_START:
1590                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1591                         return;
1592
1593                 EXPR_LITERAL_CASES
1594                 case EXPR_UNKNOWN:
1595                 case EXPR_INVALID:
1596                 case EXPR_STRING_LITERAL:
1597                 case EXPR_WIDE_STRING_LITERAL:
1598                 case EXPR_COMPOUND_LITERAL: // TODO init?
1599                 case EXPR_SIZEOF:
1600                 case EXPR_CLASSIFY_TYPE:
1601                 case EXPR_ALIGNOF:
1602                 case EXPR_FUNCNAME:
1603                 case EXPR_BUILTIN_CONSTANT_P:
1604                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1605                 case EXPR_OFFSETOF:
1606                 case EXPR_STATEMENT: // TODO
1607                 case EXPR_LABEL_ADDRESS:
1608                 case EXPR_REFERENCE_ENUM_VALUE:
1609                         return;
1610         }
1611
1612         panic("unhandled expression");
1613 }
1614
1615 static designator_t *parse_designation(void)
1616 {
1617         designator_t  *result = NULL;
1618         designator_t **anchor = &result;
1619
1620         for (;;) {
1621                 designator_t *designator;
1622                 switch (token.type) {
1623                 case '[':
1624                         designator = allocate_ast_zero(sizeof(designator[0]));
1625                         designator->source_position = token.source_position;
1626                         next_token();
1627                         add_anchor_token(']');
1628                         designator->array_index = parse_constant_expression();
1629                         rem_anchor_token(']');
1630                         expect(']', end_error);
1631                         break;
1632                 case '.':
1633                         designator = allocate_ast_zero(sizeof(designator[0]));
1634                         designator->source_position = token.source_position;
1635                         next_token();
1636                         if (token.type != T_IDENTIFIER) {
1637                                 parse_error_expected("while parsing designator",
1638                                                      T_IDENTIFIER, NULL);
1639                                 return NULL;
1640                         }
1641                         designator->symbol = token.symbol;
1642                         next_token();
1643                         break;
1644                 default:
1645                         expect('=', end_error);
1646                         return result;
1647                 }
1648
1649                 assert(designator != NULL);
1650                 *anchor = designator;
1651                 anchor  = &designator->next;
1652         }
1653 end_error:
1654         return NULL;
1655 }
1656
1657 static initializer_t *initializer_from_string(array_type_t *const type,
1658                                               const string_t *const string)
1659 {
1660         /* TODO: check len vs. size of array type */
1661         (void) type;
1662
1663         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1664         initializer->string.string = *string;
1665
1666         return initializer;
1667 }
1668
1669 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1670                                                    const string_t *const string)
1671 {
1672         /* TODO: check len vs. size of array type */
1673         (void) type;
1674
1675         initializer_t *const initializer =
1676                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1677         initializer->wide_string.string = *string;
1678
1679         return initializer;
1680 }
1681
1682 /**
1683  * Build an initializer from a given expression.
1684  */
1685 static initializer_t *initializer_from_expression(type_t *orig_type,
1686                                                   expression_t *expression)
1687 {
1688         /* TODO check that expression is a constant expression */
1689
1690         /* §6.7.8.14/15 char array may be initialized by string literals */
1691         type_t *type           = skip_typeref(orig_type);
1692         type_t *expr_type_orig = expression->base.type;
1693         type_t *expr_type      = skip_typeref(expr_type_orig);
1694
1695         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1696                 array_type_t *const array_type   = &type->array;
1697                 type_t       *const element_type = skip_typeref(array_type->element_type);
1698
1699                 if (element_type->kind == TYPE_ATOMIC) {
1700                         atomic_type_kind_t akind = element_type->atomic.akind;
1701                         switch (expression->kind) {
1702                         case EXPR_STRING_LITERAL:
1703                                 if (akind == ATOMIC_TYPE_CHAR
1704                                                 || akind == ATOMIC_TYPE_SCHAR
1705                                                 || akind == ATOMIC_TYPE_UCHAR) {
1706                                         return initializer_from_string(array_type,
1707                                                         &expression->string_literal.value);
1708                                 }
1709                                 break;
1710
1711                         case EXPR_WIDE_STRING_LITERAL: {
1712                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1713                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1714                                         return initializer_from_wide_string(array_type,
1715                                                         &expression->string_literal.value);
1716                                 }
1717                                 break;
1718                         }
1719
1720                         default:
1721                                 break;
1722                         }
1723                 }
1724         }
1725
1726         assign_error_t error = semantic_assign(type, expression);
1727         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1728                 return NULL;
1729         report_assign_error(error, type, expression, "initializer",
1730                             &expression->base.source_position);
1731
1732         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1733         result->value.value = create_implicit_cast(expression, type);
1734
1735         return result;
1736 }
1737
1738 /**
1739  * Checks if a given expression can be used as an constant initializer.
1740  */
1741 static bool is_initializer_constant(const expression_t *expression)
1742 {
1743         return
1744                 is_constant_expression(expression) != EXPR_CLASS_VARIABLE ||
1745                 is_address_constant(expression)    != EXPR_CLASS_VARIABLE;
1746 }
1747
1748 /**
1749  * Parses an scalar initializer.
1750  *
1751  * §6.7.8.11; eat {} without warning
1752  */
1753 static initializer_t *parse_scalar_initializer(type_t *type,
1754                                                bool must_be_constant)
1755 {
1756         /* there might be extra {} hierarchies */
1757         int braces = 0;
1758         if (token.type == '{') {
1759                 if (warning.other)
1760                         warningf(HERE, "extra curly braces around scalar initializer");
1761                 do {
1762                         eat('{');
1763                         ++braces;
1764                 } while (token.type == '{');
1765         }
1766
1767         expression_t *expression = parse_assignment_expression();
1768         mark_vars_read(expression, NULL);
1769         if (must_be_constant && !is_initializer_constant(expression)) {
1770                 errorf(&expression->base.source_position,
1771                        "initialisation expression '%E' is not constant",
1772                        expression);
1773         }
1774
1775         initializer_t *initializer = initializer_from_expression(type, expression);
1776
1777         if (initializer == NULL) {
1778                 errorf(&expression->base.source_position,
1779                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1780                        expression, expression->base.type, type);
1781                 /* TODO */
1782                 return NULL;
1783         }
1784
1785         bool additional_warning_displayed = false;
1786         while (braces > 0) {
1787                 next_if(',');
1788                 if (token.type != '}') {
1789                         if (!additional_warning_displayed && warning.other) {
1790                                 warningf(HERE, "additional elements in scalar initializer");
1791                                 additional_warning_displayed = true;
1792                         }
1793                 }
1794                 eat_block();
1795                 braces--;
1796         }
1797
1798         return initializer;
1799 }
1800
1801 /**
1802  * An entry in the type path.
1803  */
1804 typedef struct type_path_entry_t type_path_entry_t;
1805 struct type_path_entry_t {
1806         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1807         union {
1808                 size_t         index;          /**< For array types: the current index. */
1809                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1810         } v;
1811 };
1812
1813 /**
1814  * A type path expression a position inside compound or array types.
1815  */
1816 typedef struct type_path_t type_path_t;
1817 struct type_path_t {
1818         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1819         type_t            *top_type;     /**< type of the element the path points */
1820         size_t             max_index;    /**< largest index in outermost array */
1821 };
1822
1823 /**
1824  * Prints a type path for debugging.
1825  */
1826 static __attribute__((unused)) void debug_print_type_path(
1827                 const type_path_t *path)
1828 {
1829         size_t len = ARR_LEN(path->path);
1830
1831         for (size_t i = 0; i < len; ++i) {
1832                 const type_path_entry_t *entry = & path->path[i];
1833
1834                 type_t *type = skip_typeref(entry->type);
1835                 if (is_type_compound(type)) {
1836                         /* in gcc mode structs can have no members */
1837                         if (entry->v.compound_entry == NULL) {
1838                                 assert(i == len-1);
1839                                 continue;
1840                         }
1841                         fprintf(stderr, ".%s",
1842                                 entry->v.compound_entry->base.symbol->string);
1843                 } else if (is_type_array(type)) {
1844                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1845                 } else {
1846                         fprintf(stderr, "-INVALID-");
1847                 }
1848         }
1849         if (path->top_type != NULL) {
1850                 fprintf(stderr, "  (");
1851                 print_type(path->top_type);
1852                 fprintf(stderr, ")");
1853         }
1854 }
1855
1856 /**
1857  * Return the top type path entry, ie. in a path
1858  * (type).a.b returns the b.
1859  */
1860 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1861 {
1862         size_t len = ARR_LEN(path->path);
1863         assert(len > 0);
1864         return &path->path[len-1];
1865 }
1866
1867 /**
1868  * Enlarge the type path by an (empty) element.
1869  */
1870 static type_path_entry_t *append_to_type_path(type_path_t *path)
1871 {
1872         size_t len = ARR_LEN(path->path);
1873         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1874
1875         type_path_entry_t *result = & path->path[len];
1876         memset(result, 0, sizeof(result[0]));
1877         return result;
1878 }
1879
1880 /**
1881  * Descending into a sub-type. Enter the scope of the current top_type.
1882  */
1883 static void descend_into_subtype(type_path_t *path)
1884 {
1885         type_t *orig_top_type = path->top_type;
1886         type_t *top_type      = skip_typeref(orig_top_type);
1887
1888         type_path_entry_t *top = append_to_type_path(path);
1889         top->type              = top_type;
1890
1891         if (is_type_compound(top_type)) {
1892                 compound_t *compound  = top_type->compound.compound;
1893                 entity_t   *entry     = compound->members.entities;
1894
1895                 if (entry != NULL) {
1896                         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
1897                         top->v.compound_entry = &entry->declaration;
1898                         path->top_type = entry->declaration.type;
1899                 } else {
1900                         path->top_type = NULL;
1901                 }
1902         } else if (is_type_array(top_type)) {
1903                 top->v.index   = 0;
1904                 path->top_type = top_type->array.element_type;
1905         } else {
1906                 assert(!is_type_valid(top_type));
1907         }
1908 }
1909
1910 /**
1911  * Pop an entry from the given type path, ie. returning from
1912  * (type).a.b to (type).a
1913  */
1914 static void ascend_from_subtype(type_path_t *path)
1915 {
1916         type_path_entry_t *top = get_type_path_top(path);
1917
1918         path->top_type = top->type;
1919
1920         size_t len = ARR_LEN(path->path);
1921         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1922 }
1923
1924 /**
1925  * Pop entries from the given type path until the given
1926  * path level is reached.
1927  */
1928 static void ascend_to(type_path_t *path, size_t top_path_level)
1929 {
1930         size_t len = ARR_LEN(path->path);
1931
1932         while (len > top_path_level) {
1933                 ascend_from_subtype(path);
1934                 len = ARR_LEN(path->path);
1935         }
1936 }
1937
1938 static bool walk_designator(type_path_t *path, const designator_t *designator,
1939                             bool used_in_offsetof)
1940 {
1941         for (; designator != NULL; designator = designator->next) {
1942                 type_path_entry_t *top       = get_type_path_top(path);
1943                 type_t            *orig_type = top->type;
1944
1945                 type_t *type = skip_typeref(orig_type);
1946
1947                 if (designator->symbol != NULL) {
1948                         symbol_t *symbol = designator->symbol;
1949                         if (!is_type_compound(type)) {
1950                                 if (is_type_valid(type)) {
1951                                         errorf(&designator->source_position,
1952                                                "'.%Y' designator used for non-compound type '%T'",
1953                                                symbol, orig_type);
1954                                 }
1955
1956                                 top->type             = type_error_type;
1957                                 top->v.compound_entry = NULL;
1958                                 orig_type             = type_error_type;
1959                         } else {
1960                                 compound_t *compound = type->compound.compound;
1961                                 entity_t   *iter     = compound->members.entities;
1962                                 for (; iter != NULL; iter = iter->base.next) {
1963                                         if (iter->base.symbol == symbol) {
1964                                                 break;
1965                                         }
1966                                 }
1967                                 if (iter == NULL) {
1968                                         errorf(&designator->source_position,
1969                                                "'%T' has no member named '%Y'", orig_type, symbol);
1970                                         return false;
1971                                 }
1972                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1973                                 if (used_in_offsetof) {
1974                                         type_t *real_type = skip_typeref(iter->declaration.type);
1975                                         if (real_type->kind == TYPE_BITFIELD) {
1976                                                 errorf(&designator->source_position,
1977                                                        "offsetof designator '%Y' must not specify bitfield",
1978                                                        symbol);
1979                                                 return false;
1980                                         }
1981                                 }
1982
1983                                 top->type             = orig_type;
1984                                 top->v.compound_entry = &iter->declaration;
1985                                 orig_type             = iter->declaration.type;
1986                         }
1987                 } else {
1988                         expression_t *array_index = designator->array_index;
1989                         assert(designator->array_index != NULL);
1990
1991                         if (!is_type_array(type)) {
1992                                 if (is_type_valid(type)) {
1993                                         errorf(&designator->source_position,
1994                                                "[%E] designator used for non-array type '%T'",
1995                                                array_index, orig_type);
1996                                 }
1997                                 return false;
1998                         }
1999
2000                         long index = fold_constant_to_int(array_index);
2001                         if (!used_in_offsetof) {
2002                                 if (index < 0) {
2003                                         errorf(&designator->source_position,
2004                                                "array index [%E] must be positive", array_index);
2005                                 } else if (type->array.size_constant) {
2006                                         long array_size = type->array.size;
2007                                         if (index >= array_size) {
2008                                                 errorf(&designator->source_position,
2009                                                        "designator [%E] (%d) exceeds array size %d",
2010                                                        array_index, index, array_size);
2011                                         }
2012                                 }
2013                         }
2014
2015                         top->type    = orig_type;
2016                         top->v.index = (size_t) index;
2017                         orig_type    = type->array.element_type;
2018                 }
2019                 path->top_type = orig_type;
2020
2021                 if (designator->next != NULL) {
2022                         descend_into_subtype(path);
2023                 }
2024         }
2025         return true;
2026 }
2027
2028 static void advance_current_object(type_path_t *path, size_t top_path_level)
2029 {
2030         type_path_entry_t *top = get_type_path_top(path);
2031
2032         type_t *type = skip_typeref(top->type);
2033         if (is_type_union(type)) {
2034                 /* in unions only the first element is initialized */
2035                 top->v.compound_entry = NULL;
2036         } else if (is_type_struct(type)) {
2037                 declaration_t *entry = top->v.compound_entry;
2038
2039                 entity_t *next_entity = entry->base.next;
2040                 if (next_entity != NULL) {
2041                         assert(is_declaration(next_entity));
2042                         entry = &next_entity->declaration;
2043                 } else {
2044                         entry = NULL;
2045                 }
2046
2047                 top->v.compound_entry = entry;
2048                 if (entry != NULL) {
2049                         path->top_type = entry->type;
2050                         return;
2051                 }
2052         } else if (is_type_array(type)) {
2053                 assert(is_type_array(type));
2054
2055                 top->v.index++;
2056
2057                 if (!type->array.size_constant || top->v.index < type->array.size) {
2058                         return;
2059                 }
2060         } else {
2061                 assert(!is_type_valid(type));
2062                 return;
2063         }
2064
2065         /* we're past the last member of the current sub-aggregate, try if we
2066          * can ascend in the type hierarchy and continue with another subobject */
2067         size_t len = ARR_LEN(path->path);
2068
2069         if (len > top_path_level) {
2070                 ascend_from_subtype(path);
2071                 advance_current_object(path, top_path_level);
2072         } else {
2073                 path->top_type = NULL;
2074         }
2075 }
2076
2077 /**
2078  * skip any {...} blocks until a closing bracket is reached.
2079  */
2080 static void skip_initializers(void)
2081 {
2082         next_if('{');
2083
2084         while (token.type != '}') {
2085                 if (token.type == T_EOF)
2086                         return;
2087                 if (token.type == '{') {
2088                         eat_block();
2089                         continue;
2090                 }
2091                 next_token();
2092         }
2093 }
2094
2095 static initializer_t *create_empty_initializer(void)
2096 {
2097         static initializer_t empty_initializer
2098                 = { .list = { { INITIALIZER_LIST }, 0 } };
2099         return &empty_initializer;
2100 }
2101
2102 /**
2103  * Parse a part of an initialiser for a struct or union,
2104  */
2105 static initializer_t *parse_sub_initializer(type_path_t *path,
2106                 type_t *outer_type, size_t top_path_level,
2107                 parse_initializer_env_t *env)
2108 {
2109         if (token.type == '}') {
2110                 /* empty initializer */
2111                 return create_empty_initializer();
2112         }
2113
2114         type_t *orig_type = path->top_type;
2115         type_t *type      = NULL;
2116
2117         if (orig_type == NULL) {
2118                 /* We are initializing an empty compound. */
2119         } else {
2120                 type = skip_typeref(orig_type);
2121         }
2122
2123         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
2124
2125         while (true) {
2126                 designator_t *designator = NULL;
2127                 if (token.type == '.' || token.type == '[') {
2128                         designator = parse_designation();
2129                         goto finish_designator;
2130                 } else if (token.type == T_IDENTIFIER && look_ahead(1)->type == ':') {
2131                         /* GNU-style designator ("identifier: value") */
2132                         designator = allocate_ast_zero(sizeof(designator[0]));
2133                         designator->source_position = token.source_position;
2134                         designator->symbol          = token.symbol;
2135                         eat(T_IDENTIFIER);
2136                         eat(':');
2137
2138 finish_designator:
2139                         /* reset path to toplevel, evaluate designator from there */
2140                         ascend_to(path, top_path_level);
2141                         if (!walk_designator(path, designator, false)) {
2142                                 /* can't continue after designation error */
2143                                 goto end_error;
2144                         }
2145
2146                         initializer_t *designator_initializer
2147                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2148                         designator_initializer->designator.designator = designator;
2149                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2150
2151                         orig_type = path->top_type;
2152                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2153                 }
2154
2155                 initializer_t *sub;
2156
2157                 if (token.type == '{') {
2158                         if (type != NULL && is_type_scalar(type)) {
2159                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2160                         } else {
2161                                 if (type == NULL) {
2162                                         if (env->entity != NULL) {
2163                                                 errorf(HERE,
2164                                                      "extra brace group at end of initializer for '%Y'",
2165                                                      env->entity->base.symbol);
2166                                         } else {
2167                                                 errorf(HERE, "extra brace group at end of initializer");
2168                                         }
2169                                         eat('{');
2170                                 } else {
2171                                         eat('{');
2172                                         descend_into_subtype(path);
2173                                 }
2174
2175                                 add_anchor_token('}');
2176                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2177                                                             env);
2178                                 rem_anchor_token('}');
2179
2180                                 if (type != NULL) {
2181                                         ascend_from_subtype(path);
2182                                         expect('}', end_error);
2183                                 } else {
2184                                         expect('}', end_error);
2185                                         goto error_parse_next;
2186                                 }
2187                         }
2188                 } else {
2189                         /* must be an expression */
2190                         expression_t *expression = parse_assignment_expression();
2191                         mark_vars_read(expression, NULL);
2192
2193                         if (env->must_be_constant && !is_initializer_constant(expression)) {
2194                                 errorf(&expression->base.source_position,
2195                                        "Initialisation expression '%E' is not constant",
2196                                        expression);
2197                         }
2198
2199                         if (type == NULL) {
2200                                 /* we are already outside, ... */
2201                                 if (outer_type == NULL)
2202                                         goto error_parse_next;
2203                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2204                                 if (is_type_compound(outer_type_skip) &&
2205                                     !outer_type_skip->compound.compound->complete) {
2206                                         goto error_parse_next;
2207                                 }
2208                                 goto error_excess;
2209                         }
2210
2211                         /* handle { "string" } special case */
2212                         if ((expression->kind == EXPR_STRING_LITERAL
2213                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2214                                         && outer_type != NULL) {
2215                                 sub = initializer_from_expression(outer_type, expression);
2216                                 if (sub != NULL) {
2217                                         next_if(',');
2218                                         if (token.type != '}' && warning.other) {
2219                                                 warningf(HERE, "excessive elements in initializer for type '%T'",
2220                                                                  orig_type);
2221                                         }
2222                                         /* TODO: eat , ... */
2223                                         return sub;
2224                                 }
2225                         }
2226
2227                         /* descend into subtypes until expression matches type */
2228                         while (true) {
2229                                 orig_type = path->top_type;
2230                                 type      = skip_typeref(orig_type);
2231
2232                                 sub = initializer_from_expression(orig_type, expression);
2233                                 if (sub != NULL) {
2234                                         break;
2235                                 }
2236                                 if (!is_type_valid(type)) {
2237                                         goto end_error;
2238                                 }
2239                                 if (is_type_scalar(type)) {
2240                                         errorf(&expression->base.source_position,
2241                                                         "expression '%E' doesn't match expected type '%T'",
2242                                                         expression, orig_type);
2243                                         goto end_error;
2244                                 }
2245
2246                                 descend_into_subtype(path);
2247                         }
2248                 }
2249
2250                 /* update largest index of top array */
2251                 const type_path_entry_t *first      = &path->path[0];
2252                 type_t                  *first_type = first->type;
2253                 first_type                          = skip_typeref(first_type);
2254                 if (is_type_array(first_type)) {
2255                         size_t index = first->v.index;
2256                         if (index > path->max_index)
2257                                 path->max_index = index;
2258                 }
2259
2260                 if (type != NULL) {
2261                         /* append to initializers list */
2262                         ARR_APP1(initializer_t*, initializers, sub);
2263                 } else {
2264 error_excess:
2265                         if (warning.other) {
2266                                 if (env->entity != NULL) {
2267                                         warningf(HERE, "excess elements in initializer for '%Y'",
2268                                                  env->entity->base.symbol);
2269                                 } else {
2270                                         warningf(HERE, "excess elements in initializer");
2271                                 }
2272                         }
2273                 }
2274
2275 error_parse_next:
2276                 if (token.type == '}') {
2277                         break;
2278                 }
2279                 expect(',', end_error);
2280                 if (token.type == '}') {
2281                         break;
2282                 }
2283
2284                 if (type != NULL) {
2285                         /* advance to the next declaration if we are not at the end */
2286                         advance_current_object(path, top_path_level);
2287                         orig_type = path->top_type;
2288                         if (orig_type != NULL)
2289                                 type = skip_typeref(orig_type);
2290                         else
2291                                 type = NULL;
2292                 }
2293         }
2294
2295         size_t len  = ARR_LEN(initializers);
2296         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2297         initializer_t *result = allocate_ast_zero(size);
2298         result->kind          = INITIALIZER_LIST;
2299         result->list.len      = len;
2300         memcpy(&result->list.initializers, initializers,
2301                len * sizeof(initializers[0]));
2302
2303         DEL_ARR_F(initializers);
2304         ascend_to(path, top_path_level+1);
2305
2306         return result;
2307
2308 end_error:
2309         skip_initializers();
2310         DEL_ARR_F(initializers);
2311         ascend_to(path, top_path_level+1);
2312         return NULL;
2313 }
2314
2315 static expression_t *make_size_literal(size_t value)
2316 {
2317         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2318         literal->base.type    = type_size_t;
2319
2320         char buf[128];
2321         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2322         literal->literal.value = make_string(buf);
2323
2324         return literal;
2325 }
2326
2327 /**
2328  * Parses an initializer. Parsers either a compound literal
2329  * (env->declaration == NULL) or an initializer of a declaration.
2330  */
2331 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2332 {
2333         type_t        *type      = skip_typeref(env->type);
2334         size_t         max_index = 0;
2335         initializer_t *result;
2336
2337         if (is_type_scalar(type)) {
2338                 result = parse_scalar_initializer(type, env->must_be_constant);
2339         } else if (token.type == '{') {
2340                 eat('{');
2341
2342                 type_path_t path;
2343                 memset(&path, 0, sizeof(path));
2344                 path.top_type = env->type;
2345                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2346
2347                 descend_into_subtype(&path);
2348
2349                 add_anchor_token('}');
2350                 result = parse_sub_initializer(&path, env->type, 1, env);
2351                 rem_anchor_token('}');
2352
2353                 max_index = path.max_index;
2354                 DEL_ARR_F(path.path);
2355
2356                 expect('}', end_error);
2357 end_error:;
2358         } else {
2359                 /* parse_scalar_initializer() also works in this case: we simply
2360                  * have an expression without {} around it */
2361                 result = parse_scalar_initializer(type, env->must_be_constant);
2362         }
2363
2364         /* §6.7.8:22 array initializers for arrays with unknown size determine
2365          * the array type size */
2366         if (is_type_array(type) && type->array.size_expression == NULL
2367                         && result != NULL) {
2368                 size_t size;
2369                 switch (result->kind) {
2370                 case INITIALIZER_LIST:
2371                         assert(max_index != 0xdeadbeaf);
2372                         size = max_index + 1;
2373                         break;
2374
2375                 case INITIALIZER_STRING:
2376                         size = result->string.string.size;
2377                         break;
2378
2379                 case INITIALIZER_WIDE_STRING:
2380                         size = result->wide_string.string.size;
2381                         break;
2382
2383                 case INITIALIZER_DESIGNATOR:
2384                 case INITIALIZER_VALUE:
2385                         /* can happen for parse errors */
2386                         size = 0;
2387                         break;
2388
2389                 default:
2390                         internal_errorf(HERE, "invalid initializer type");
2391                 }
2392
2393                 type_t *new_type = duplicate_type(type);
2394
2395                 new_type->array.size_expression   = make_size_literal(size);
2396                 new_type->array.size_constant     = true;
2397                 new_type->array.has_implicit_size = true;
2398                 new_type->array.size              = size;
2399                 env->type = new_type;
2400         }
2401
2402         return result;
2403 }
2404
2405 static void append_entity(scope_t *scope, entity_t *entity)
2406 {
2407         if (scope->last_entity != NULL) {
2408                 scope->last_entity->base.next = entity;
2409         } else {
2410                 scope->entities = entity;
2411         }
2412         entity->base.parent_entity = current_entity;
2413         scope->last_entity         = entity;
2414 }
2415
2416
2417 static compound_t *parse_compound_type_specifier(bool is_struct)
2418 {
2419         source_position_t const pos = *HERE;
2420         eat(is_struct ? T_struct : T_union);
2421
2422         symbol_t    *symbol     = NULL;
2423         entity_t    *entity     = NULL;
2424         attribute_t *attributes = NULL;
2425
2426         if (token.type == T___attribute__) {
2427                 attributes = parse_attributes(NULL);
2428         }
2429
2430         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2431         if (token.type == T_IDENTIFIER) {
2432                 /* the compound has a name, check if we have seen it already */
2433                 symbol = token.symbol;
2434                 entity = get_tag(symbol, kind);
2435                 next_token();
2436
2437                 if (entity != NULL) {
2438                         if (entity->base.parent_scope != current_scope &&
2439                             (token.type == '{' || token.type == ';')) {
2440                                 /* we're in an inner scope and have a definition. Shadow
2441                                  * existing definition in outer scope */
2442                                 entity = NULL;
2443                         } else if (entity->compound.complete && token.type == '{') {
2444                                 errorf(&pos, "multiple definitions of '%s %Y' (previous definition %P)",
2445                                        is_struct ? "struct" : "union", symbol,
2446                                        &entity->base.source_position);
2447                                 /* clear members in the hope to avoid further errors */
2448                                 entity->compound.members.entities = NULL;
2449                         }
2450                 }
2451         } else if (token.type != '{') {
2452                 char const *const msg =
2453                         is_struct ? "while parsing struct type specifier" :
2454                                     "while parsing union type specifier";
2455                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2456
2457                 return NULL;
2458         }
2459
2460         if (entity == NULL) {
2461                 entity = allocate_entity_zero(kind);
2462
2463                 entity->compound.alignment   = 1;
2464                 entity->base.namespc         = NAMESPACE_TAG;
2465                 entity->base.source_position = pos;
2466                 entity->base.symbol          = symbol;
2467                 entity->base.parent_scope    = current_scope;
2468                 if (symbol != NULL) {
2469                         environment_push(entity);
2470                 }
2471                 append_entity(current_scope, entity);
2472         }
2473
2474         if (token.type == '{') {
2475                 parse_compound_type_entries(&entity->compound);
2476
2477                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2478                 if (symbol == NULL) {
2479                         assert(anonymous_entity == NULL);
2480                         anonymous_entity = entity;
2481                 }
2482         }
2483
2484         if (attributes != NULL) {
2485                 handle_entity_attributes(attributes, entity);
2486         }
2487
2488         return &entity->compound;
2489 }
2490
2491 static void parse_enum_entries(type_t *const enum_type)
2492 {
2493         eat('{');
2494
2495         if (token.type == '}') {
2496                 errorf(HERE, "empty enum not allowed");
2497                 next_token();
2498                 return;
2499         }
2500
2501         add_anchor_token('}');
2502         do {
2503                 if (token.type != T_IDENTIFIER) {
2504                         parse_error_expected("while parsing enum entry", T_IDENTIFIER, NULL);
2505                         eat_block();
2506                         rem_anchor_token('}');
2507                         return;
2508                 }
2509
2510                 entity_t *entity             = allocate_entity_zero(ENTITY_ENUM_VALUE);
2511                 entity->enum_value.enum_type = enum_type;
2512                 entity->base.namespc         = NAMESPACE_NORMAL;
2513                 entity->base.symbol          = token.symbol;
2514                 entity->base.source_position = token.source_position;
2515                 next_token();
2516
2517                 if (next_if('=')) {
2518                         expression_t *value = parse_constant_expression();
2519
2520                         value = create_implicit_cast(value, enum_type);
2521                         entity->enum_value.value = value;
2522
2523                         /* TODO semantic */
2524                 }
2525
2526                 record_entity(entity, false);
2527         } while (next_if(',') && token.type != '}');
2528         rem_anchor_token('}');
2529
2530         expect('}', end_error);
2531
2532 end_error:
2533         ;
2534 }
2535
2536 static type_t *parse_enum_specifier(void)
2537 {
2538         source_position_t const pos = *HERE;
2539         entity_t               *entity;
2540         symbol_t               *symbol;
2541
2542         eat(T_enum);
2543         switch (token.type) {
2544                 case T_IDENTIFIER:
2545                         symbol = token.symbol;
2546                         entity = get_tag(symbol, ENTITY_ENUM);
2547                         next_token();
2548
2549                         if (entity != NULL) {
2550                                 if (entity->base.parent_scope != current_scope &&
2551                                                 (token.type == '{' || token.type == ';')) {
2552                                         /* we're in an inner scope and have a definition. Shadow
2553                                          * existing definition in outer scope */
2554                                         entity = NULL;
2555                                 } else if (entity->enume.complete && token.type == '{') {
2556                                         errorf(&pos, "multiple definitions of 'enum %Y' (previous definition %P)",
2557                                                         symbol, &entity->base.source_position);
2558                                 }
2559                         }
2560                         break;
2561
2562                 case '{':
2563                         entity = NULL;
2564                         symbol = NULL;
2565                         break;
2566
2567                 default:
2568                         parse_error_expected("while parsing enum type specifier",
2569                                         T_IDENTIFIER, '{', NULL);
2570                         return NULL;
2571         }
2572
2573         if (entity == NULL) {
2574                 entity                       = allocate_entity_zero(ENTITY_ENUM);
2575                 entity->base.namespc         = NAMESPACE_TAG;
2576                 entity->base.source_position = pos;
2577                 entity->base.symbol          = symbol;
2578                 entity->base.parent_scope    = current_scope;
2579         }
2580
2581         type_t *const type = allocate_type_zero(TYPE_ENUM);
2582         type->enumt.enume  = &entity->enume;
2583         type->enumt.akind  = ATOMIC_TYPE_INT;
2584
2585         if (token.type == '{') {
2586                 if (symbol != NULL) {
2587                         environment_push(entity);
2588                 }
2589                 append_entity(current_scope, entity);
2590                 entity->enume.complete = true;
2591
2592                 parse_enum_entries(type);
2593                 parse_attributes(NULL);
2594
2595                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2596                 if (symbol == NULL) {
2597                         assert(anonymous_entity == NULL);
2598                         anonymous_entity = entity;
2599                 }
2600         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2601                 errorf(HERE, "'enum %Y' used before definition (incomplete enums are a GNU extension)",
2602                        symbol);
2603         }
2604
2605         return type;
2606 }
2607
2608 /**
2609  * if a symbol is a typedef to another type, return true
2610  */
2611 static bool is_typedef_symbol(symbol_t *symbol)
2612 {
2613         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2614         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2615 }
2616
2617 static type_t *parse_typeof(void)
2618 {
2619         eat(T___typeof__);
2620
2621         type_t *type;
2622
2623         expect('(', end_error);
2624         add_anchor_token(')');
2625
2626         expression_t *expression  = NULL;
2627
2628         bool old_type_prop     = in_type_prop;
2629         bool old_gcc_extension = in_gcc_extension;
2630         in_type_prop           = true;
2631
2632         while (next_if(T___extension__)) {
2633                 /* This can be a prefix to a typename or an expression. */
2634                 in_gcc_extension = true;
2635         }
2636         switch (token.type) {
2637         case T_IDENTIFIER:
2638                 if (is_typedef_symbol(token.symbol)) {
2639         TYPENAME_START
2640                         type = parse_typename();
2641                 } else {
2642         default:
2643                         expression = parse_expression();
2644                         type       = revert_automatic_type_conversion(expression);
2645                 }
2646                 break;
2647         }
2648         in_type_prop     = old_type_prop;
2649         in_gcc_extension = old_gcc_extension;
2650
2651         rem_anchor_token(')');
2652         expect(')', end_error);
2653
2654         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2655         typeof_type->typeoft.expression  = expression;
2656         typeof_type->typeoft.typeof_type = type;
2657
2658         return typeof_type;
2659 end_error:
2660         return NULL;
2661 }
2662
2663 typedef enum specifiers_t {
2664         SPECIFIER_SIGNED    = 1 << 0,
2665         SPECIFIER_UNSIGNED  = 1 << 1,
2666         SPECIFIER_LONG      = 1 << 2,
2667         SPECIFIER_INT       = 1 << 3,
2668         SPECIFIER_DOUBLE    = 1 << 4,
2669         SPECIFIER_CHAR      = 1 << 5,
2670         SPECIFIER_WCHAR_T   = 1 << 6,
2671         SPECIFIER_SHORT     = 1 << 7,
2672         SPECIFIER_LONG_LONG = 1 << 8,
2673         SPECIFIER_FLOAT     = 1 << 9,
2674         SPECIFIER_BOOL      = 1 << 10,
2675         SPECIFIER_VOID      = 1 << 11,
2676         SPECIFIER_INT8      = 1 << 12,
2677         SPECIFIER_INT16     = 1 << 13,
2678         SPECIFIER_INT32     = 1 << 14,
2679         SPECIFIER_INT64     = 1 << 15,
2680         SPECIFIER_INT128    = 1 << 16,
2681         SPECIFIER_COMPLEX   = 1 << 17,
2682         SPECIFIER_IMAGINARY = 1 << 18,
2683 } specifiers_t;
2684
2685 static type_t *get_typedef_type(symbol_t *symbol)
2686 {
2687         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2688         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2689                 return NULL;
2690
2691         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2692         type->typedeft.typedefe = &entity->typedefe;
2693
2694         return type;
2695 }
2696
2697 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2698 {
2699         expect('(', end_error);
2700
2701         attribute_property_argument_t *property
2702                 = allocate_ast_zero(sizeof(*property));
2703
2704         do {
2705                 if (token.type != T_IDENTIFIER) {
2706                         parse_error_expected("while parsing property declspec",
2707                                              T_IDENTIFIER, NULL);
2708                         goto end_error;
2709                 }
2710
2711                 bool is_put;
2712                 symbol_t *symbol = token.symbol;
2713                 next_token();
2714                 if (strcmp(symbol->string, "put") == 0) {
2715                         is_put = true;
2716                 } else if (strcmp(symbol->string, "get") == 0) {
2717                         is_put = false;
2718                 } else {
2719                         errorf(HERE, "expected put or get in property declspec");
2720                         goto end_error;
2721                 }
2722                 expect('=', end_error);
2723                 if (token.type != T_IDENTIFIER) {
2724                         parse_error_expected("while parsing property declspec",
2725                                              T_IDENTIFIER, NULL);
2726                         goto end_error;
2727                 }
2728                 if (is_put) {
2729                         property->put_symbol = token.symbol;
2730                 } else {
2731                         property->get_symbol = token.symbol;
2732                 }
2733                 next_token();
2734         } while (next_if(','));
2735
2736         attribute->a.property = property;
2737
2738         expect(')', end_error);
2739
2740 end_error:
2741         return attribute;
2742 }
2743
2744 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2745 {
2746         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2747         if (next_if(T_restrict)) {
2748                 kind = ATTRIBUTE_MS_RESTRICT;
2749         } else if (token.type == T_IDENTIFIER) {
2750                 const char *name = token.symbol->string;
2751                 next_token();
2752                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2753                      ++k) {
2754                         const char *attribute_name = get_attribute_name(k);
2755                         if (attribute_name != NULL && strcmp(attribute_name, name) == 0) {
2756                                 kind = k;
2757                                 break;
2758                         }
2759                 }
2760
2761                 if (kind == ATTRIBUTE_UNKNOWN && warning.attribute) {
2762                         warningf(HERE, "unknown __declspec '%s' ignored", name);
2763                 }
2764         } else {
2765                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2766                 return NULL;
2767         }
2768
2769         attribute_t *attribute = allocate_attribute_zero(kind);
2770
2771         if (kind == ATTRIBUTE_MS_PROPERTY) {
2772                 return parse_attribute_ms_property(attribute);
2773         }
2774
2775         /* parse arguments */
2776         if (next_if('('))
2777                 attribute->a.arguments = parse_attribute_arguments();
2778
2779         return attribute;
2780 }
2781
2782 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2783 {
2784         eat(T__declspec);
2785
2786         expect('(', end_error);
2787
2788         if (next_if(')'))
2789                 return NULL;
2790
2791         add_anchor_token(')');
2792
2793         attribute_t **anchor = &first;
2794         do {
2795                 while (*anchor != NULL)
2796                         anchor = &(*anchor)->next;
2797
2798                 attribute_t *attribute
2799                         = parse_microsoft_extended_decl_modifier_single();
2800                 if (attribute == NULL)
2801                         goto end_error;
2802
2803                 *anchor = attribute;
2804                 anchor  = &attribute->next;
2805         } while (next_if(','));
2806
2807         rem_anchor_token(')');
2808         expect(')', end_error);
2809         return first;
2810
2811 end_error:
2812         rem_anchor_token(')');
2813         return first;
2814 }
2815
2816 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2817 {
2818         entity_t *entity             = allocate_entity_zero(kind);
2819         entity->base.namespc         = NAMESPACE_NORMAL;
2820         entity->base.source_position = *HERE;
2821         entity->base.symbol          = symbol;
2822         if (is_declaration(entity)) {
2823                 entity->declaration.type     = type_error_type;
2824                 entity->declaration.implicit = true;
2825         } else if (kind == ENTITY_TYPEDEF) {
2826                 entity->typedefe.type    = type_error_type;
2827                 entity->typedefe.builtin = true;
2828         }
2829         if (kind != ENTITY_COMPOUND_MEMBER)
2830                 record_entity(entity, false);
2831         return entity;
2832 }
2833
2834 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2835 {
2836         type_t            *type              = NULL;
2837         type_qualifiers_t  qualifiers        = TYPE_QUALIFIER_NONE;
2838         unsigned           type_specifiers   = 0;
2839         bool               newtype           = false;
2840         bool               saw_error         = false;
2841         bool               old_gcc_extension = in_gcc_extension;
2842
2843         memset(specifiers, 0, sizeof(*specifiers));
2844         specifiers->source_position = token.source_position;
2845
2846         while (true) {
2847                 specifiers->attributes = parse_attributes(specifiers->attributes);
2848
2849                 switch (token.type) {
2850                 /* storage class */
2851 #define MATCH_STORAGE_CLASS(token, class)                                  \
2852                 case token:                                                        \
2853                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2854                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2855                         }                                                              \
2856                         specifiers->storage_class = class;                             \
2857                         if (specifiers->thread_local)                                  \
2858                                 goto check_thread_storage_class;                           \
2859                         next_token();                                                  \
2860                         break;
2861
2862                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2863                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2864                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2865                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2866                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2867
2868                 case T__declspec:
2869                         specifiers->attributes
2870                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2871                         break;
2872
2873                 case T___thread:
2874                         if (specifiers->thread_local) {
2875                                 errorf(HERE, "duplicate '__thread'");
2876                         } else {
2877                                 specifiers->thread_local = true;
2878 check_thread_storage_class:
2879                                 switch (specifiers->storage_class) {
2880                                         case STORAGE_CLASS_EXTERN:
2881                                         case STORAGE_CLASS_NONE:
2882                                         case STORAGE_CLASS_STATIC:
2883                                                 break;
2884
2885                                                 char const* wrong;
2886                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2887                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2888                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2889 wrong_thread_storage_class:
2890                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2891                                                 break;
2892                                 }
2893                         }
2894                         next_token();
2895                         break;
2896
2897                 /* type qualifiers */
2898 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2899                 case token:                                                     \
2900                         qualifiers |= qualifier;                                    \
2901                         next_token();                                               \
2902                         break
2903
2904                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2905                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2906                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2907                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2908                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2909                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2910                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2911                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2912
2913                 case T___extension__:
2914                         next_token();
2915                         in_gcc_extension = true;
2916                         break;
2917
2918                 /* type specifiers */
2919 #define MATCH_SPECIFIER(token, specifier, name)                         \
2920                 case token:                                                     \
2921                         if (type_specifiers & specifier) {                           \
2922                                 errorf(HERE, "multiple " name " type specifiers given"); \
2923                         } else {                                                    \
2924                                 type_specifiers |= specifier;                           \
2925                         }                                                           \
2926                         next_token();                                               \
2927                         break
2928
2929                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2930                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2931                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2932                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2933                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2934                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2935                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2936                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2937                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2938                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2939                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2940                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2941                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2942                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2943                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2944                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2945                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2946                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2947
2948                 case T_inline:
2949                         next_token();
2950                         specifiers->is_inline = true;
2951                         break;
2952
2953 #if 0
2954                 case T__forceinline:
2955                         next_token();
2956                         specifiers->modifiers |= DM_FORCEINLINE;
2957                         break;
2958 #endif
2959
2960                 case T_long:
2961                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2962                                 errorf(HERE, "too many long type specifiers given");
2963                         } else if (type_specifiers & SPECIFIER_LONG) {
2964                                 type_specifiers |= SPECIFIER_LONG_LONG;
2965                         } else {
2966                                 type_specifiers |= SPECIFIER_LONG;
2967                         }
2968                         next_token();
2969                         break;
2970
2971 #define CHECK_DOUBLE_TYPE()        \
2972                         if ( type != NULL)     \
2973                                 errorf(HERE, "multiple data types in declaration specifiers");
2974
2975                 case T_struct:
2976                         CHECK_DOUBLE_TYPE();
2977                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2978
2979                         type->compound.compound = parse_compound_type_specifier(true);
2980                         break;
2981                 case T_union:
2982                         CHECK_DOUBLE_TYPE();
2983                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2984                         type->compound.compound = parse_compound_type_specifier(false);
2985                         break;
2986                 case T_enum:
2987                         CHECK_DOUBLE_TYPE();
2988                         type = parse_enum_specifier();
2989                         break;
2990                 case T___typeof__:
2991                         CHECK_DOUBLE_TYPE();
2992                         type = parse_typeof();
2993                         break;
2994                 case T___builtin_va_list:
2995                         CHECK_DOUBLE_TYPE();
2996                         type = duplicate_type(type_valist);
2997                         next_token();
2998                         break;
2999
3000                 case T_IDENTIFIER: {
3001                         /* only parse identifier if we haven't found a type yet */
3002                         if (type != NULL || type_specifiers != 0) {
3003                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
3004                                  * declaration, so it doesn't generate errors about expecting '(' or
3005                                  * '{' later on. */
3006                                 switch (look_ahead(1)->type) {
3007                                         STORAGE_CLASSES
3008                                         TYPE_SPECIFIERS
3009                                         case T_const:
3010                                         case T_restrict:
3011                                         case T_volatile:
3012                                         case T_inline:
3013                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
3014                                         case T_IDENTIFIER:
3015                                         case '&':
3016                                         case '*':
3017                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
3018                                                 next_token();
3019                                                 continue;
3020
3021                                         default:
3022                                                 goto finish_specifiers;
3023                                 }
3024                         }
3025
3026                         type_t *const typedef_type = get_typedef_type(token.symbol);
3027                         if (typedef_type == NULL) {
3028                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
3029                                  * declaration, so it doesn't generate 'implicit int' followed by more
3030                                  * errors later on. */
3031                                 token_type_t const la1_type = (token_type_t)look_ahead(1)->type;
3032                                 switch (la1_type) {
3033                                         DECLARATION_START
3034                                         case T_IDENTIFIER:
3035                                         case '&':
3036                                         case '*': {
3037                                                 errorf(HERE, "%K does not name a type", &token);
3038
3039                                                 entity_t *entity =
3040                                                         create_error_entity(token.symbol, ENTITY_TYPEDEF);
3041
3042                                                 type = allocate_type_zero(TYPE_TYPEDEF);
3043                                                 type->typedeft.typedefe = &entity->typedefe;
3044
3045                                                 next_token();
3046                                                 saw_error = true;
3047                                                 continue;
3048                                         }
3049
3050                                         default:
3051                                                 goto finish_specifiers;
3052                                 }
3053                         }
3054
3055                         next_token();
3056                         type = typedef_type;
3057                         break;
3058                 }
3059
3060                 /* function specifier */
3061                 default:
3062                         goto finish_specifiers;
3063                 }
3064         }
3065
3066 finish_specifiers:
3067         specifiers->attributes = parse_attributes(specifiers->attributes);
3068
3069         in_gcc_extension = old_gcc_extension;
3070
3071         if (type == NULL || (saw_error && type_specifiers != 0)) {
3072                 atomic_type_kind_t atomic_type;
3073
3074                 /* match valid basic types */
3075                 switch (type_specifiers) {
3076                 case SPECIFIER_VOID:
3077                         atomic_type = ATOMIC_TYPE_VOID;
3078                         break;
3079                 case SPECIFIER_WCHAR_T:
3080                         atomic_type = ATOMIC_TYPE_WCHAR_T;
3081                         break;
3082                 case SPECIFIER_CHAR:
3083                         atomic_type = ATOMIC_TYPE_CHAR;
3084                         break;
3085                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
3086                         atomic_type = ATOMIC_TYPE_SCHAR;
3087                         break;
3088                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
3089                         atomic_type = ATOMIC_TYPE_UCHAR;
3090                         break;
3091                 case SPECIFIER_SHORT:
3092                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
3093                 case SPECIFIER_SHORT | SPECIFIER_INT:
3094                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3095                         atomic_type = ATOMIC_TYPE_SHORT;
3096                         break;
3097                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
3098                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
3099                         atomic_type = ATOMIC_TYPE_USHORT;
3100                         break;
3101                 case SPECIFIER_INT:
3102                 case SPECIFIER_SIGNED:
3103                 case SPECIFIER_SIGNED | SPECIFIER_INT:
3104                         atomic_type = ATOMIC_TYPE_INT;
3105                         break;
3106                 case SPECIFIER_UNSIGNED:
3107                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
3108                         atomic_type = ATOMIC_TYPE_UINT;
3109                         break;
3110                 case SPECIFIER_LONG:
3111                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
3112                 case SPECIFIER_LONG | SPECIFIER_INT:
3113                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3114                         atomic_type = ATOMIC_TYPE_LONG;
3115                         break;
3116                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
3117                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
3118                         atomic_type = ATOMIC_TYPE_ULONG;
3119                         break;
3120
3121                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3122                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3123                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
3124                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3125                         | SPECIFIER_INT:
3126                         atomic_type = ATOMIC_TYPE_LONGLONG;
3127                         goto warn_about_long_long;
3128
3129                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
3130                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
3131                         | SPECIFIER_INT:
3132                         atomic_type = ATOMIC_TYPE_ULONGLONG;
3133 warn_about_long_long:
3134                         if (warning.long_long) {
3135                                 warningf(&specifiers->source_position,
3136                                          "ISO C90 does not support 'long long'");
3137                         }
3138                         break;
3139
3140                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
3141                         atomic_type = unsigned_int8_type_kind;
3142                         break;
3143
3144                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
3145                         atomic_type = unsigned_int16_type_kind;
3146                         break;
3147
3148                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
3149                         atomic_type = unsigned_int32_type_kind;
3150                         break;
3151
3152                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
3153                         atomic_type = unsigned_int64_type_kind;
3154                         break;
3155
3156                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
3157                         atomic_type = unsigned_int128_type_kind;
3158                         break;
3159
3160                 case SPECIFIER_INT8:
3161                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
3162                         atomic_type = int8_type_kind;
3163                         break;
3164
3165                 case SPECIFIER_INT16:
3166                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
3167                         atomic_type = int16_type_kind;
3168                         break;
3169
3170                 case SPECIFIER_INT32:
3171                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
3172                         atomic_type = int32_type_kind;
3173                         break;
3174
3175                 case SPECIFIER_INT64:
3176                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
3177                         atomic_type = int64_type_kind;
3178                         break;
3179
3180                 case SPECIFIER_INT128:
3181                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
3182                         atomic_type = int128_type_kind;
3183                         break;
3184
3185                 case SPECIFIER_FLOAT:
3186                         atomic_type = ATOMIC_TYPE_FLOAT;
3187                         break;
3188                 case SPECIFIER_DOUBLE:
3189                         atomic_type = ATOMIC_TYPE_DOUBLE;
3190                         break;
3191                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
3192                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3193                         break;
3194                 case SPECIFIER_BOOL:
3195                         atomic_type = ATOMIC_TYPE_BOOL;
3196                         break;
3197                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
3198                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
3199                         atomic_type = ATOMIC_TYPE_FLOAT;
3200                         break;
3201                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3202                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3203                         atomic_type = ATOMIC_TYPE_DOUBLE;
3204                         break;
3205                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
3206                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
3207                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
3208                         break;
3209                 default:
3210                         /* invalid specifier combination, give an error message */
3211                         if (type_specifiers == 0) {
3212                                 if (!saw_error) {
3213                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3214                                         if (!(c_mode & _CXX) && !strict_mode) {
3215                                                 if (warning.implicit_int) {
3216                                                         warningf(HERE, "no type specifiers in declaration, using 'int'");
3217                                                 }
3218                                                 atomic_type = ATOMIC_TYPE_INT;
3219                                                 break;
3220                                         } else {
3221                                                 errorf(HERE, "no type specifiers given in declaration");
3222                                         }
3223                                 }
3224                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3225                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3226                                 errorf(HERE, "signed and unsigned specifiers given");
3227                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3228                                 errorf(HERE, "only integer types can be signed or unsigned");
3229                         } else {
3230                                 errorf(HERE, "multiple datatypes in declaration");
3231                         }
3232                         goto end_error;
3233                 }
3234
3235                 if (type_specifiers & SPECIFIER_COMPLEX) {
3236                         type                = allocate_type_zero(TYPE_COMPLEX);
3237                         type->complex.akind = atomic_type;
3238                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3239                         type                  = allocate_type_zero(TYPE_IMAGINARY);
3240                         type->imaginary.akind = atomic_type;
3241                 } else {
3242                         type                 = allocate_type_zero(TYPE_ATOMIC);
3243                         type->atomic.akind   = atomic_type;
3244                 }
3245                 newtype = true;
3246         } else if (type_specifiers != 0) {
3247                 errorf(HERE, "multiple datatypes in declaration");
3248         }
3249
3250         /* FIXME: check type qualifiers here */
3251         type->base.qualifiers = qualifiers;
3252
3253         if (newtype) {
3254                 type = identify_new_type(type);
3255         } else {
3256                 type = typehash_insert(type);
3257         }
3258
3259         if (specifiers->attributes != NULL)
3260                 type = handle_type_attributes(specifiers->attributes, type);
3261         specifiers->type = type;
3262         return;
3263
3264 end_error:
3265         specifiers->type = type_error_type;
3266 }
3267
3268 static type_qualifiers_t parse_type_qualifiers(void)
3269 {
3270         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3271
3272         while (true) {
3273                 switch (token.type) {
3274                 /* type qualifiers */
3275                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3276                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3277                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3278                 /* microsoft extended type modifiers */
3279                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3280                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3281                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3282                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3283                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3284
3285                 default:
3286                         return qualifiers;
3287                 }
3288         }
3289 }
3290
3291 /**
3292  * Parses an K&R identifier list
3293  */
3294 static void parse_identifier_list(scope_t *scope)
3295 {
3296         do {
3297                 entity_t *entity = allocate_entity_zero(ENTITY_PARAMETER);
3298                 entity->base.source_position = token.source_position;
3299                 entity->base.namespc         = NAMESPACE_NORMAL;
3300                 entity->base.symbol          = token.symbol;
3301                 /* a K&R parameter has no type, yet */
3302                 next_token();
3303
3304                 if (scope != NULL)
3305                         append_entity(scope, entity);
3306         } while (next_if(',') && token.type == T_IDENTIFIER);
3307 }
3308
3309 static entity_t *parse_parameter(void)
3310 {
3311         declaration_specifiers_t specifiers;
3312         parse_declaration_specifiers(&specifiers);
3313
3314         entity_t *entity = parse_declarator(&specifiers,
3315                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3316         anonymous_entity = NULL;
3317         return entity;
3318 }
3319
3320 static void semantic_parameter_incomplete(const entity_t *entity)
3321 {
3322         assert(entity->kind == ENTITY_PARAMETER);
3323
3324         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3325          *             list in a function declarator that is part of a
3326          *             definition of that function shall not have
3327          *             incomplete type. */
3328         type_t *type = skip_typeref(entity->declaration.type);
3329         if (is_type_incomplete(type)) {
3330                 errorf(&entity->base.source_position,
3331                                 "parameter '%#T' has incomplete type",
3332                                 entity->declaration.type, entity->base.symbol);
3333         }
3334 }
3335
3336 static bool has_parameters(void)
3337 {
3338         /* func(void) is not a parameter */
3339         if (token.type == T_IDENTIFIER) {
3340                 entity_t const *const entity = get_entity(token.symbol, NAMESPACE_NORMAL);
3341                 if (entity == NULL)
3342                         return true;
3343                 if (entity->kind != ENTITY_TYPEDEF)
3344                         return true;
3345                 if (skip_typeref(entity->typedefe.type) != type_void)
3346                         return true;
3347         } else if (token.type != T_void) {
3348                 return true;
3349         }
3350         if (look_ahead(1)->type != ')')
3351                 return true;
3352         next_token();
3353         return false;
3354 }
3355
3356 /**
3357  * Parses function type parameters (and optionally creates variable_t entities
3358  * for them in a scope)
3359  */
3360 static void parse_parameters(function_type_t *type, scope_t *scope)
3361 {
3362         eat('(');
3363         add_anchor_token(')');
3364         int saved_comma_state = save_and_reset_anchor_state(',');
3365
3366         if (token.type == T_IDENTIFIER &&
3367             !is_typedef_symbol(token.symbol)) {
3368                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
3369                 if (la1_type == ',' || la1_type == ')') {
3370                         type->kr_style_parameters = true;
3371                         parse_identifier_list(scope);
3372                         goto parameters_finished;
3373                 }
3374         }
3375
3376         if (token.type == ')') {
3377                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3378                 if (!(c_mode & _CXX))
3379                         type->unspecified_parameters = true;
3380         } else if (has_parameters()) {
3381                 function_parameter_t **anchor = &type->parameters;
3382                 do {
3383                         switch (token.type) {
3384                         case T_DOTDOTDOT:
3385                                 next_token();
3386                                 type->variadic = true;
3387                                 goto parameters_finished;
3388
3389                         case T_IDENTIFIER:
3390                         case T___extension__:
3391                         DECLARATION_START
3392                         {
3393                                 entity_t *entity = parse_parameter();
3394                                 if (entity->kind == ENTITY_TYPEDEF) {
3395                                         errorf(&entity->base.source_position,
3396                                                         "typedef not allowed as function parameter");
3397                                         break;
3398                                 }
3399                                 assert(is_declaration(entity));
3400
3401                                 semantic_parameter_incomplete(entity);
3402
3403                                 function_parameter_t *const parameter =
3404                                         allocate_parameter(entity->declaration.type);
3405
3406                                 if (scope != NULL) {
3407                                         append_entity(scope, entity);
3408                                 }
3409
3410                                 *anchor = parameter;
3411                                 anchor  = &parameter->next;
3412                                 break;
3413                         }
3414
3415                         default:
3416                                 goto parameters_finished;
3417                         }
3418                 } while (next_if(','));
3419         }
3420
3421 parameters_finished:
3422         rem_anchor_token(')');
3423         expect(')', end_error);
3424
3425 end_error:
3426         restore_anchor_state(',', saved_comma_state);
3427 }
3428
3429 typedef enum construct_type_kind_t {
3430         CONSTRUCT_INVALID,
3431         CONSTRUCT_POINTER,
3432         CONSTRUCT_REFERENCE,
3433         CONSTRUCT_FUNCTION,
3434         CONSTRUCT_ARRAY
3435 } construct_type_kind_t;
3436
3437 typedef union construct_type_t construct_type_t;
3438
3439 typedef struct construct_type_base_t {
3440         construct_type_kind_t  kind;
3441         source_position_t      pos;
3442         construct_type_t      *next;
3443 } construct_type_base_t;
3444
3445 typedef struct parsed_pointer_t {
3446         construct_type_base_t  base;
3447         type_qualifiers_t      type_qualifiers;
3448         variable_t            *base_variable;  /**< MS __based extension. */
3449 } parsed_pointer_t;
3450
3451 typedef struct parsed_reference_t {
3452         construct_type_base_t base;
3453 } parsed_reference_t;
3454
3455 typedef struct construct_function_type_t {
3456         construct_type_base_t  base;
3457         type_t                *function_type;
3458 } construct_function_type_t;
3459
3460 typedef struct parsed_array_t {
3461         construct_type_base_t  base;
3462         type_qualifiers_t      type_qualifiers;
3463         bool                   is_static;
3464         bool                   is_variable;
3465         expression_t          *size;
3466 } parsed_array_t;
3467
3468 union construct_type_t {
3469         construct_type_kind_t     kind;
3470         construct_type_base_t     base;
3471         parsed_pointer_t          pointer;
3472         parsed_reference_t        reference;
3473         construct_function_type_t function;
3474         parsed_array_t            array;
3475 };
3476
3477 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3478 {
3479         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3480         memset(cons, 0, size);
3481         cons->kind     = kind;
3482         cons->base.pos = *HERE;
3483         return cons;
3484 }
3485
3486 /* §6.7.5.1 */
3487 static construct_type_t *parse_pointer_declarator(void)
3488 {
3489         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3490         eat('*');
3491         cons->pointer.type_qualifiers = parse_type_qualifiers();
3492         //cons->pointer.base_variable   = base_variable;
3493
3494         return cons;
3495 }
3496
3497 /* ISO/IEC 14882:1998(E) §8.3.2 */
3498 static construct_type_t *parse_reference_declarator(void)
3499 {
3500         if (!(c_mode & _CXX))
3501                 errorf(HERE, "references are only available for C++");
3502
3503         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3504         eat('&');
3505
3506         return cons;
3507 }
3508
3509 /* §6.7.5.2 */
3510 static construct_type_t *parse_array_declarator(void)
3511 {
3512         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3513         parsed_array_t   *const array = &cons->array;
3514
3515         eat('[');
3516         add_anchor_token(']');
3517
3518         bool is_static = next_if(T_static);
3519
3520         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3521
3522         if (!is_static)
3523                 is_static = next_if(T_static);
3524
3525         array->type_qualifiers = type_qualifiers;
3526         array->is_static       = is_static;
3527
3528         expression_t *size = NULL;
3529         if (token.type == '*' && look_ahead(1)->type == ']') {
3530                 array->is_variable = true;
3531                 next_token();
3532         } else if (token.type != ']') {
3533                 size = parse_assignment_expression();
3534
3535                 /* §6.7.5.2:1  Array size must have integer type */
3536                 type_t *const orig_type = size->base.type;
3537                 type_t *const type      = skip_typeref(orig_type);
3538                 if (!is_type_integer(type) && is_type_valid(type)) {
3539                         errorf(&size->base.source_position,
3540                                "array size '%E' must have integer type but has type '%T'",
3541                                size, orig_type);
3542                 }
3543
3544                 array->size = size;
3545                 mark_vars_read(size, NULL);
3546         }
3547
3548         if (is_static && size == NULL)
3549                 errorf(&array->base.pos, "static array parameters require a size");
3550
3551         rem_anchor_token(']');
3552         expect(']', end_error);
3553
3554 end_error:
3555         return cons;
3556 }
3557
3558 /* §6.7.5.3 */
3559 static construct_type_t *parse_function_declarator(scope_t *scope)
3560 {
3561         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3562
3563         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3564         function_type_t *ftype = &type->function;
3565
3566         ftype->linkage            = current_linkage;
3567         ftype->calling_convention = CC_DEFAULT;
3568
3569         parse_parameters(ftype, scope);
3570
3571         cons->function.function_type = type;
3572
3573         return cons;
3574 }
3575
3576 typedef struct parse_declarator_env_t {
3577         bool               may_be_abstract : 1;
3578         bool               must_be_abstract : 1;
3579         decl_modifiers_t   modifiers;
3580         symbol_t          *symbol;
3581         source_position_t  source_position;
3582         scope_t            parameters;
3583         attribute_t       *attributes;
3584 } parse_declarator_env_t;
3585
3586 /* §6.7.5 */
3587 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3588 {
3589         /* construct a single linked list of construct_type_t's which describe
3590          * how to construct the final declarator type */
3591         construct_type_t  *first      = NULL;
3592         construct_type_t **anchor     = &first;
3593
3594         env->attributes = parse_attributes(env->attributes);
3595
3596         for (;;) {
3597                 construct_type_t *type;
3598                 //variable_t       *based = NULL; /* MS __based extension */
3599                 switch (token.type) {
3600                         case '&':
3601                                 type = parse_reference_declarator();
3602                                 break;
3603
3604                         case T__based: {
3605                                 panic("based not supported anymore");
3606                                 /* FALLTHROUGH */
3607                         }
3608
3609                         case '*':
3610                                 type = parse_pointer_declarator();
3611                                 break;
3612
3613                         default:
3614                                 goto ptr_operator_end;
3615                 }
3616
3617                 *anchor = type;
3618                 anchor  = &type->base.next;
3619
3620                 /* TODO: find out if this is correct */
3621                 env->attributes = parse_attributes(env->attributes);
3622         }
3623
3624 ptr_operator_end: ;
3625         construct_type_t *inner_types = NULL;
3626
3627         switch (token.type) {
3628         case T_IDENTIFIER:
3629                 if (env->must_be_abstract) {
3630                         errorf(HERE, "no identifier expected in typename");
3631                 } else {
3632                         env->symbol          = token.symbol;
3633                         env->source_position = token.source_position;
3634                 }
3635                 next_token();
3636                 break;
3637
3638         case '(': {
3639                 /* Parenthesized declarator or function declarator? */
3640                 token_t const *const la1 = look_ahead(1);
3641                 switch (la1->type) {
3642                         case T_IDENTIFIER:
3643                                 if (is_typedef_symbol(la1->symbol)) {
3644                         case ')':
3645                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3646                                          * interpreted as ``function with no parameter specification'', rather
3647                                          * than redundant parentheses around the omitted identifier. */
3648                         default:
3649                                         /* Function declarator. */
3650                                         if (!env->may_be_abstract) {
3651                                                 errorf(HERE, "function declarator must have a name");
3652                                         }
3653                                 } else {
3654                         case '&':
3655                         case '(':
3656                         case '*':
3657                         case '[':
3658                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3659                                         /* Paranthesized declarator. */
3660                                         next_token();
3661                                         add_anchor_token(')');
3662                                         inner_types = parse_inner_declarator(env);
3663                                         if (inner_types != NULL) {
3664                                                 /* All later declarators only modify the return type */
3665                                                 env->must_be_abstract = true;
3666                                         }
3667                                         rem_anchor_token(')');
3668                                         expect(')', end_error);
3669                                 }
3670                                 break;
3671                 }
3672                 break;
3673         }
3674
3675         default:
3676                 if (env->may_be_abstract)
3677                         break;
3678                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3679                 eat_until_anchor();
3680                 return NULL;
3681         }
3682
3683         construct_type_t **const p = anchor;
3684
3685         for (;;) {
3686                 construct_type_t *type;
3687                 switch (token.type) {
3688                 case '(': {
3689                         scope_t *scope = NULL;
3690                         if (!env->must_be_abstract) {
3691                                 scope = &env->parameters;
3692                         }
3693
3694                         type = parse_function_declarator(scope);
3695                         break;
3696                 }
3697                 case '[':
3698                         type = parse_array_declarator();
3699                         break;
3700                 default:
3701                         goto declarator_finished;
3702                 }
3703
3704                 /* insert in the middle of the list (at p) */
3705                 type->base.next = *p;
3706                 *p              = type;
3707                 if (anchor == p)
3708                         anchor = &type->base.next;
3709         }
3710
3711 declarator_finished:
3712         /* append inner_types at the end of the list, we don't to set anchor anymore
3713          * as it's not needed anymore */
3714         *anchor = inner_types;
3715
3716         return first;
3717 end_error:
3718         return NULL;
3719 }
3720
3721 static type_t *construct_declarator_type(construct_type_t *construct_list,
3722                                          type_t *type)
3723 {
3724         construct_type_t *iter = construct_list;
3725         for (; iter != NULL; iter = iter->base.next) {
3726                 source_position_t const* const pos = &iter->base.pos;
3727                 switch (iter->kind) {
3728                 case CONSTRUCT_INVALID:
3729                         break;
3730                 case CONSTRUCT_FUNCTION: {
3731                         construct_function_type_t *function      = &iter->function;
3732                         type_t                    *function_type = function->function_type;
3733
3734                         function_type->function.return_type = type;
3735
3736                         type_t *skipped_return_type = skip_typeref(type);
3737                         /* §6.7.5.3:1 */
3738                         if (is_type_function(skipped_return_type)) {
3739                                 errorf(pos, "function returning function is not allowed");
3740                         } else if (is_type_array(skipped_return_type)) {
3741                                 errorf(pos, "function returning array is not allowed");
3742                         } else {
3743                                 if (skipped_return_type->base.qualifiers != 0 && warning.other) {
3744                                         warningf(pos, "type qualifiers in return type of function type are meaningless");
3745                                 }
3746                         }
3747
3748                         /* The function type was constructed earlier.  Freeing it here will
3749                          * destroy other types. */
3750                         type = typehash_insert(function_type);
3751                         continue;
3752                 }
3753
3754                 case CONSTRUCT_POINTER: {
3755                         if (is_type_reference(skip_typeref(type)))
3756                                 errorf(pos, "cannot declare a pointer to reference");
3757
3758                         parsed_pointer_t *pointer = &iter->pointer;
3759                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3760                         continue;
3761                 }
3762
3763                 case CONSTRUCT_REFERENCE:
3764                         if (is_type_reference(skip_typeref(type)))
3765                                 errorf(pos, "cannot declare a reference to reference");
3766
3767                         type = make_reference_type(type);
3768                         continue;
3769
3770                 case CONSTRUCT_ARRAY: {
3771                         if (is_type_reference(skip_typeref(type)))
3772                                 errorf(pos, "cannot declare an array of references");
3773
3774                         parsed_array_t *array      = &iter->array;
3775                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3776
3777                         expression_t *size_expression = array->size;
3778                         if (size_expression != NULL) {
3779                                 size_expression
3780                                         = create_implicit_cast(size_expression, type_size_t);
3781                         }
3782
3783                         array_type->base.qualifiers       = array->type_qualifiers;
3784                         array_type->array.element_type    = type;
3785                         array_type->array.is_static       = array->is_static;
3786                         array_type->array.is_variable     = array->is_variable;
3787                         array_type->array.size_expression = size_expression;
3788
3789                         if (size_expression != NULL) {
3790                                 switch (is_constant_expression(size_expression)) {
3791                                         case EXPR_CLASS_CONSTANT: {
3792                                                 long const size = fold_constant_to_int(size_expression);
3793                                                 array_type->array.size          = size;
3794                                                 array_type->array.size_constant = true;
3795                                                 /* §6.7.5.2:1  If the expression is a constant expression, it shall
3796                                                  * have a value greater than zero. */
3797                                                 if (size <= 0) {
3798                                                         if (size < 0 || !GNU_MODE) {
3799                                                                 errorf(&size_expression->base.source_position,
3800                                                                                 "size of array must be greater than zero");
3801                                                         } else if (warning.other) {
3802                                                                 warningf(&size_expression->base.source_position,
3803                                                                                 "zero length arrays are a GCC extension");
3804                                                         }
3805                                                 }
3806                                                 break;
3807                                         }
3808
3809                                         case EXPR_CLASS_VARIABLE:
3810                                                 array_type->array.is_vla = true;
3811                                                 break;
3812
3813                                         case EXPR_CLASS_ERROR:
3814                                                 break;
3815                                 }
3816                         }
3817
3818                         type_t *skipped_type = skip_typeref(type);
3819                         /* §6.7.5.2:1 */
3820                         if (is_type_incomplete(skipped_type)) {
3821                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3822                         } else if (is_type_function(skipped_type)) {
3823                                 errorf(pos, "array of functions is not allowed");
3824                         }
3825                         type = identify_new_type(array_type);
3826                         continue;
3827                 }
3828                 }
3829                 internal_errorf(pos, "invalid type construction found");
3830         }
3831
3832         return type;
3833 }
3834
3835 static type_t *automatic_type_conversion(type_t *orig_type);
3836
3837 static type_t *semantic_parameter(const source_position_t *pos,
3838                                   type_t *type,
3839                                   const declaration_specifiers_t *specifiers,
3840                                   symbol_t *symbol)
3841 {
3842         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3843          *             shall be adjusted to ``qualified pointer to type'',
3844          *             [...]
3845          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3846          *             type'' shall be adjusted to ``pointer to function
3847          *             returning type'', as in 6.3.2.1. */
3848         type = automatic_type_conversion(type);
3849
3850         if (specifiers->is_inline && is_type_valid(type)) {
3851                 errorf(pos, "parameter '%#T' declared 'inline'", type, symbol);
3852         }
3853
3854         /* §6.9.1:6  The declarations in the declaration list shall contain
3855          *           no storage-class specifier other than register and no
3856          *           initializations. */
3857         if (specifiers->thread_local || (
3858                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3859                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3860            ) {
3861                 errorf(pos, "invalid storage class for parameter '%#T'", type, symbol);
3862         }
3863
3864         /* delay test for incomplete type, because we might have (void)
3865          * which is legal but incomplete... */
3866
3867         return type;
3868 }
3869
3870 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3871                                   declarator_flags_t flags)
3872 {
3873         parse_declarator_env_t env;
3874         memset(&env, 0, sizeof(env));
3875         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3876
3877         construct_type_t *construct_type = parse_inner_declarator(&env);
3878         type_t           *orig_type      =
3879                 construct_declarator_type(construct_type, specifiers->type);
3880         type_t           *type           = skip_typeref(orig_type);
3881
3882         if (construct_type != NULL) {
3883                 obstack_free(&temp_obst, construct_type);
3884         }
3885
3886         attribute_t *attributes = parse_attributes(env.attributes);
3887         /* append (shared) specifier attribute behind attributes of this
3888          * declarator */
3889         attribute_t **anchor = &attributes;
3890         while (*anchor != NULL)
3891                 anchor = &(*anchor)->next;
3892         *anchor = specifiers->attributes;
3893
3894         entity_t *entity;
3895         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3896                 entity                       = allocate_entity_zero(ENTITY_TYPEDEF);
3897                 entity->base.namespc         = NAMESPACE_NORMAL;
3898                 entity->base.symbol          = env.symbol;
3899                 entity->base.source_position = env.source_position;
3900                 entity->typedefe.type        = orig_type;
3901
3902                 if (anonymous_entity != NULL) {
3903                         if (is_type_compound(type)) {
3904                                 assert(anonymous_entity->compound.alias == NULL);
3905                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3906                                        anonymous_entity->kind == ENTITY_UNION);
3907                                 anonymous_entity->compound.alias = entity;
3908                                 anonymous_entity = NULL;
3909                         } else if (is_type_enum(type)) {
3910                                 assert(anonymous_entity->enume.alias == NULL);
3911                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3912                                 anonymous_entity->enume.alias = entity;
3913                                 anonymous_entity = NULL;
3914                         }
3915                 }
3916         } else {
3917                 /* create a declaration type entity */
3918                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3919                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
3920
3921                         if (env.symbol != NULL) {
3922                                 if (specifiers->is_inline && is_type_valid(type)) {
3923                                         errorf(&env.source_position,
3924                                                         "compound member '%Y' declared 'inline'", env.symbol);
3925                                 }
3926
3927                                 if (specifiers->thread_local ||
3928                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3929                                         errorf(&env.source_position,
3930                                                         "compound member '%Y' must have no storage class",
3931                                                         env.symbol);
3932                                 }
3933                         }
3934                 } else if (flags & DECL_IS_PARAMETER) {
3935                         orig_type = semantic_parameter(&env.source_position, orig_type,
3936                                                        specifiers, env.symbol);
3937
3938                         entity = allocate_entity_zero(ENTITY_PARAMETER);
3939                 } else if (is_type_function(type)) {
3940                         entity = allocate_entity_zero(ENTITY_FUNCTION);
3941
3942                         entity->function.is_inline      = specifiers->is_inline;
3943                         entity->function.elf_visibility = default_visibility;
3944                         entity->function.parameters     = env.parameters;
3945
3946                         if (env.symbol != NULL) {
3947                                 /* this needs fixes for C++ */
3948                                 bool in_function_scope = current_function != NULL;
3949
3950                                 if (specifiers->thread_local || (
3951                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3952                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3953                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3954                                                 )) {
3955                                         errorf(&env.source_position,
3956                                                         "invalid storage class for function '%Y'", env.symbol);
3957                                 }
3958                         }
3959                 } else {
3960                         entity = allocate_entity_zero(ENTITY_VARIABLE);
3961
3962                         entity->variable.elf_visibility = default_visibility;
3963                         entity->variable.thread_local   = specifiers->thread_local;
3964
3965                         if (env.symbol != NULL) {
3966                                 if (specifiers->is_inline && is_type_valid(type)) {
3967                                         errorf(&env.source_position,
3968                                                         "variable '%Y' declared 'inline'", env.symbol);
3969                                 }
3970
3971                                 bool invalid_storage_class = false;
3972                                 if (current_scope == file_scope) {
3973                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3974                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3975                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3976                                                 invalid_storage_class = true;
3977                                         }
3978                                 } else {
3979                                         if (specifiers->thread_local &&
3980                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3981                                                 invalid_storage_class = true;
3982                                         }
3983                                 }
3984                                 if (invalid_storage_class) {
3985                                         errorf(&env.source_position,
3986                                                         "invalid storage class for variable '%Y'", env.symbol);
3987                                 }
3988                         }
3989                 }
3990
3991                 if (env.symbol != NULL) {
3992                         entity->base.symbol          = env.symbol;
3993                         entity->base.source_position = env.source_position;
3994                 } else {
3995                         entity->base.source_position = specifiers->source_position;
3996                 }
3997                 entity->base.namespc           = NAMESPACE_NORMAL;
3998                 entity->declaration.type       = orig_type;
3999                 entity->declaration.alignment  = get_type_alignment(orig_type);
4000                 entity->declaration.modifiers  = env.modifiers;
4001                 entity->declaration.attributes = attributes;
4002
4003                 storage_class_t storage_class = specifiers->storage_class;
4004                 entity->declaration.declared_storage_class = storage_class;
4005
4006                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
4007                         storage_class = STORAGE_CLASS_AUTO;
4008                 entity->declaration.storage_class = storage_class;
4009         }
4010
4011         if (attributes != NULL) {
4012                 handle_entity_attributes(attributes, entity);
4013         }
4014
4015         return entity;
4016 }
4017
4018 static type_t *parse_abstract_declarator(type_t *base_type)
4019 {
4020         parse_declarator_env_t env;
4021         memset(&env, 0, sizeof(env));
4022         env.may_be_abstract = true;
4023         env.must_be_abstract = true;
4024
4025         construct_type_t *construct_type = parse_inner_declarator(&env);
4026
4027         type_t *result = construct_declarator_type(construct_type, base_type);
4028         if (construct_type != NULL) {
4029                 obstack_free(&temp_obst, construct_type);
4030         }
4031         result = handle_type_attributes(env.attributes, result);
4032
4033         return result;
4034 }
4035
4036 /**
4037  * Check if the declaration of main is suspicious.  main should be a
4038  * function with external linkage, returning int, taking either zero
4039  * arguments, two, or three arguments of appropriate types, ie.
4040  *
4041  * int main([ int argc, char **argv [, char **env ] ]).
4042  *
4043  * @param decl    the declaration to check
4044  * @param type    the function type of the declaration
4045  */
4046 static void check_main(const entity_t *entity)
4047 {
4048         const source_position_t *pos = &entity->base.source_position;
4049         if (entity->kind != ENTITY_FUNCTION) {
4050                 warningf(pos, "'main' is not a function");
4051                 return;
4052         }
4053
4054         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
4055                 warningf(pos, "'main' is normally a non-static function");
4056         }
4057
4058         type_t *type = skip_typeref(entity->declaration.type);
4059         assert(is_type_function(type));
4060
4061         function_type_t *func_type = &type->function;
4062         if (!types_compatible(skip_typeref(func_type->return_type), type_int)) {
4063                 warningf(pos, "return type of 'main' should be 'int', but is '%T'",
4064                          func_type->return_type);
4065         }
4066         const function_parameter_t *parm = func_type->parameters;
4067         if (parm != NULL) {
4068                 type_t *const first_type        = skip_typeref(parm->type);
4069                 type_t *const first_type_unqual = get_unqualified_type(first_type);
4070                 if (!types_compatible(first_type_unqual, type_int)) {
4071                         warningf(pos,
4072                                  "first argument of 'main' should be 'int', but is '%T'",
4073                                  parm->type);
4074                 }
4075                 parm = parm->next;
4076                 if (parm != NULL) {
4077                         type_t *const second_type = skip_typeref(parm->type);
4078                         type_t *const second_type_unqual
4079                                 = get_unqualified_type(second_type);
4080                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
4081                                 warningf(pos, "second argument of 'main' should be 'char**', but is '%T'",
4082                                          parm->type);
4083                         }
4084                         parm = parm->next;
4085                         if (parm != NULL) {
4086                                 type_t *const third_type = skip_typeref(parm->type);
4087                                 type_t *const third_type_unqual
4088                                         = get_unqualified_type(third_type);
4089                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
4090                                         warningf(pos, "third argument of 'main' should be 'char**', but is '%T'",
4091                                                  parm->type);
4092                                 }
4093                                 parm = parm->next;
4094                                 if (parm != NULL)
4095                                         goto warn_arg_count;
4096                         }
4097                 } else {
4098 warn_arg_count:
4099                         warningf(pos, "'main' takes only zero, two or three arguments");
4100                 }
4101         }
4102 }
4103
4104 /**
4105  * Check if a symbol is the equal to "main".
4106  */
4107 static bool is_sym_main(const symbol_t *const sym)
4108 {
4109         return strcmp(sym->string, "main") == 0;
4110 }
4111
4112 static void error_redefined_as_different_kind(const source_position_t *pos,
4113                 const entity_t *old, entity_kind_t new_kind)
4114 {
4115         errorf(pos, "redeclaration of %s '%Y' as %s (declared %P)",
4116                get_entity_kind_name(old->kind), old->base.symbol,
4117                get_entity_kind_name(new_kind), &old->base.source_position);
4118 }
4119
4120 static bool is_entity_valid(entity_t *const ent)
4121 {
4122         if (is_declaration(ent)) {
4123                 return is_type_valid(skip_typeref(ent->declaration.type));
4124         } else if (ent->kind == ENTITY_TYPEDEF) {
4125                 return is_type_valid(skip_typeref(ent->typedefe.type));
4126         }
4127         return true;
4128 }
4129
4130 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
4131 {
4132         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
4133                 if (attributes_equal(tattr, attr))
4134                         return true;
4135         }
4136         return false;
4137 }
4138
4139 /**
4140  * test wether new_list contains any attributes not included in old_list
4141  */
4142 static bool has_new_attributes(const attribute_t *old_list,
4143                                const attribute_t *new_list)
4144 {
4145         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
4146                 if (!contains_attribute(old_list, attr))
4147                         return true;
4148         }
4149         return false;
4150 }
4151
4152 /**
4153  * Merge in attributes from an attribute list (probably from a previous
4154  * declaration with the same name). Warning: destroys the old structure
4155  * of the attribute list - don't reuse attributes after this call.
4156  */
4157 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
4158 {
4159         attribute_t *next;
4160         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
4161                 next = attr->next;
4162                 if (contains_attribute(decl->attributes, attr))
4163                         continue;
4164
4165                 /* move attribute to new declarations attributes list */
4166                 attr->next       = decl->attributes;
4167                 decl->attributes = attr;
4168         }
4169 }
4170
4171 /**
4172  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
4173  * for various problems that occur for multiple definitions
4174  */
4175 entity_t *record_entity(entity_t *entity, const bool is_definition)
4176 {
4177         const symbol_t *const    symbol  = entity->base.symbol;
4178         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
4179         const source_position_t *pos     = &entity->base.source_position;
4180
4181         /* can happen in error cases */
4182         if (symbol == NULL)
4183                 return entity;
4184
4185         entity_t *const previous_entity = get_entity(symbol, namespc);
4186         /* pushing the same entity twice will break the stack structure */
4187         assert(previous_entity != entity);
4188
4189         if (entity->kind == ENTITY_FUNCTION) {
4190                 type_t *const orig_type = entity->declaration.type;
4191                 type_t *const type      = skip_typeref(orig_type);
4192
4193                 assert(is_type_function(type));
4194                 if (type->function.unspecified_parameters &&
4195                                 warning.strict_prototypes &&
4196                                 previous_entity == NULL) {
4197                         warningf(pos, "function declaration '%#T' is not a prototype",
4198                                          orig_type, symbol);
4199                 }
4200
4201                 if (warning.main && current_scope == file_scope
4202                                 && is_sym_main(symbol)) {
4203                         check_main(entity);
4204                 }
4205         }
4206
4207         if (is_declaration(entity) &&
4208                         warning.nested_externs &&
4209                         entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
4210                         current_scope != file_scope) {
4211                 warningf(pos, "nested extern declaration of '%#T'",
4212                          entity->declaration.type, symbol);
4213         }
4214
4215         if (previous_entity != NULL) {
4216                 if (previous_entity->base.parent_scope == &current_function->parameters &&
4217                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
4218                         assert(previous_entity->kind == ENTITY_PARAMETER);
4219                         errorf(pos,
4220                                         "declaration '%#T' redeclares the parameter '%#T' (declared %P)",
4221                                         entity->declaration.type, symbol,
4222                                         previous_entity->declaration.type, symbol,
4223                                         &previous_entity->base.source_position);
4224                         goto finish;
4225                 }
4226
4227                 if (previous_entity->base.parent_scope == current_scope) {
4228                         if (previous_entity->kind != entity->kind) {
4229                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
4230                                         error_redefined_as_different_kind(pos, previous_entity,
4231                                                         entity->kind);
4232                                 }
4233                                 goto finish;
4234                         }
4235                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
4236                                 errorf(pos, "redeclaration of enum entry '%Y' (declared %P)",
4237                                                 symbol, &previous_entity->base.source_position);
4238                                 goto finish;
4239                         }
4240                         if (previous_entity->kind == ENTITY_TYPEDEF) {
4241                                 /* TODO: C++ allows this for exactly the same type */
4242                                 errorf(pos, "redefinition of typedef '%Y' (declared %P)",
4243                                                 symbol, &previous_entity->base.source_position);
4244                                 goto finish;
4245                         }
4246
4247                         /* at this point we should have only VARIABLES or FUNCTIONS */
4248                         assert(is_declaration(previous_entity) && is_declaration(entity));
4249
4250                         declaration_t *const prev_decl = &previous_entity->declaration;
4251                         declaration_t *const decl      = &entity->declaration;
4252
4253                         /* can happen for K&R style declarations */
4254                         if (prev_decl->type       == NULL             &&
4255                                         previous_entity->kind == ENTITY_PARAMETER &&
4256                                         entity->kind          == ENTITY_PARAMETER) {
4257                                 prev_decl->type                   = decl->type;
4258                                 prev_decl->storage_class          = decl->storage_class;
4259                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4260                                 prev_decl->modifiers              = decl->modifiers;
4261                                 return previous_entity;
4262                         }
4263
4264                         type_t *const orig_type = decl->type;
4265                         assert(orig_type != NULL);
4266                         type_t *const type      = skip_typeref(orig_type);
4267                         type_t *const prev_type = skip_typeref(prev_decl->type);
4268
4269                         if (!types_compatible(type, prev_type)) {
4270                                 errorf(pos,
4271                                                 "declaration '%#T' is incompatible with '%#T' (declared %P)",
4272                                                 orig_type, symbol, prev_decl->type, symbol,
4273                                                 &previous_entity->base.source_position);
4274                         } else {
4275                                 unsigned old_storage_class = prev_decl->storage_class;
4276
4277                                 if (warning.redundant_decls               &&
4278                                                 is_definition                     &&
4279                                                 !prev_decl->used                  &&
4280                                                 !(prev_decl->modifiers & DM_USED) &&
4281                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4282                                         warningf(&previous_entity->base.source_position,
4283                                                         "unnecessary static forward declaration for '%#T'",
4284                                                         prev_decl->type, symbol);
4285                                 }
4286
4287                                 storage_class_t new_storage_class = decl->storage_class;
4288
4289                                 /* pretend no storage class means extern for function
4290                                  * declarations (except if the previous declaration is neither
4291                                  * none nor extern) */
4292                                 if (entity->kind == ENTITY_FUNCTION) {
4293                                         /* the previous declaration could have unspecified parameters or
4294                                          * be a typedef, so use the new type */
4295                                         if (prev_type->function.unspecified_parameters || is_definition)
4296                                                 prev_decl->type = type;
4297
4298                                         switch (old_storage_class) {
4299                                                 case STORAGE_CLASS_NONE:
4300                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4301                                                         /* FALLTHROUGH */
4302
4303                                                 case STORAGE_CLASS_EXTERN:
4304                                                         if (is_definition) {
4305                                                                 if (warning.missing_prototypes &&
4306                                                                                 prev_type->function.unspecified_parameters &&
4307                                                                                 !is_sym_main(symbol)) {
4308                                                                         warningf(pos, "no previous prototype for '%#T'",
4309                                                                                         orig_type, symbol);
4310                                                                 }
4311                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4312                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4313                                                         }
4314                                                         break;
4315
4316                                                 default:
4317                                                         break;
4318                                         }
4319                                 } else if (is_type_incomplete(prev_type)) {
4320                                         prev_decl->type = type;
4321                                 }
4322
4323                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4324                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4325
4326 warn_redundant_declaration: ;
4327                                         bool has_new_attrs
4328                                                 = has_new_attributes(prev_decl->attributes,
4329                                                                      decl->attributes);
4330                                         if (has_new_attrs) {
4331                                                 merge_in_attributes(decl, prev_decl->attributes);
4332                                         } else if (!is_definition        &&
4333                                                         warning.redundant_decls  &&
4334                                                         is_type_valid(prev_type) &&
4335                                                         strcmp(previous_entity->base.source_position.input_name,
4336                                                                 "<builtin>") != 0) {
4337                                                 warningf(pos,
4338                                                          "redundant declaration for '%Y' (declared %P)",
4339                                                          symbol, &previous_entity->base.source_position);
4340                                         }
4341                                 } else if (current_function == NULL) {
4342                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4343                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4344                                                 errorf(pos,
4345                                                        "static declaration of '%Y' follows non-static declaration (declared %P)",
4346                                                        symbol, &previous_entity->base.source_position);
4347                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4348                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4349                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4350                                         } else {
4351                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4352                                                 if (c_mode & _CXX)
4353                                                         goto error_redeclaration;
4354                                                 goto warn_redundant_declaration;
4355                                         }
4356                                 } else if (is_type_valid(prev_type)) {
4357                                         if (old_storage_class == new_storage_class) {
4358 error_redeclaration:
4359                                                 errorf(pos, "redeclaration of '%Y' (declared %P)",
4360                                                                 symbol, &previous_entity->base.source_position);
4361                                         } else {
4362                                                 errorf(pos,
4363                                                                 "redeclaration of '%Y' with different linkage (declared %P)",
4364                                                                 symbol, &previous_entity->base.source_position);
4365                                         }
4366                                 }
4367                         }
4368
4369                         prev_decl->modifiers |= decl->modifiers;
4370                         if (entity->kind == ENTITY_FUNCTION) {
4371                                 previous_entity->function.is_inline |= entity->function.is_inline;
4372                         }
4373                         return previous_entity;
4374                 }
4375
4376                 if (warning.shadow ||
4377                                 (warning.shadow_local && previous_entity->base.parent_scope != file_scope)) {
4378                         warningf(pos, "%s '%Y' shadows %s (declared %P)",
4379                                         get_entity_kind_name(entity->kind), symbol,
4380                                         get_entity_kind_name(previous_entity->kind),
4381                                         &previous_entity->base.source_position);
4382                 }
4383         }
4384
4385         if (entity->kind == ENTITY_FUNCTION) {
4386                 if (is_definition &&
4387                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC) {
4388                         if (warning.missing_prototypes && !is_sym_main(symbol)) {
4389                                 warningf(pos, "no previous prototype for '%#T'",
4390                                          entity->declaration.type, symbol);
4391                         } else if (warning.missing_declarations && !is_sym_main(symbol)) {
4392                                 warningf(pos, "no previous declaration for '%#T'",
4393                                          entity->declaration.type, symbol);
4394                         }
4395                 }
4396         } else if (warning.missing_declarations &&
4397                         entity->kind == ENTITY_VARIABLE &&
4398                         current_scope == file_scope) {
4399                 declaration_t *declaration = &entity->declaration;
4400                 if (declaration->storage_class == STORAGE_CLASS_NONE) {
4401                         warningf(pos, "no previous declaration for '%#T'",
4402                                  declaration->type, symbol);
4403                 }
4404         }
4405
4406 finish:
4407         assert(entity->base.parent_scope == NULL);
4408         assert(current_scope != NULL);
4409
4410         entity->base.parent_scope = current_scope;
4411         entity->base.namespc      = NAMESPACE_NORMAL;
4412         environment_push(entity);
4413         append_entity(current_scope, entity);
4414
4415         return entity;
4416 }
4417
4418 static void parser_error_multiple_definition(entity_t *entity,
4419                 const source_position_t *source_position)
4420 {
4421         errorf(source_position, "multiple definition of '%Y' (declared %P)",
4422                entity->base.symbol, &entity->base.source_position);
4423 }
4424
4425 static bool is_declaration_specifier(const token_t *token,
4426                                      bool only_specifiers_qualifiers)
4427 {
4428         switch (token->type) {
4429                 TYPE_SPECIFIERS
4430                 TYPE_QUALIFIERS
4431                         return true;
4432                 case T_IDENTIFIER:
4433                         return is_typedef_symbol(token->symbol);
4434
4435                 case T___extension__:
4436                 STORAGE_CLASSES
4437                         return !only_specifiers_qualifiers;
4438
4439                 default:
4440                         return false;
4441         }
4442 }
4443
4444 static void parse_init_declarator_rest(entity_t *entity)
4445 {
4446         type_t *orig_type = type_error_type;
4447
4448         if (entity->base.kind == ENTITY_TYPEDEF) {
4449                 errorf(&entity->base.source_position,
4450                        "typedef '%Y' is initialized (use __typeof__ instead)",
4451                        entity->base.symbol);
4452         } else {
4453                 assert(is_declaration(entity));
4454                 orig_type = entity->declaration.type;
4455         }
4456         eat('=');
4457
4458         type_t *type = skip_typeref(orig_type);
4459
4460         if (entity->kind == ENTITY_VARIABLE
4461                         && entity->variable.initializer != NULL) {
4462                 parser_error_multiple_definition(entity, HERE);
4463         }
4464
4465         declaration_t *const declaration = &entity->declaration;
4466         bool must_be_constant = false;
4467         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4468             entity->base.parent_scope  == file_scope) {
4469                 must_be_constant = true;
4470         }
4471
4472         if (is_type_function(type)) {
4473                 errorf(&entity->base.source_position,
4474                        "function '%#T' is initialized like a variable",
4475                        orig_type, entity->base.symbol);
4476                 orig_type = type_error_type;
4477         }
4478
4479         parse_initializer_env_t env;
4480         env.type             = orig_type;
4481         env.must_be_constant = must_be_constant;
4482         env.entity           = entity;
4483         current_init_decl    = entity;
4484
4485         initializer_t *initializer = parse_initializer(&env);
4486         current_init_decl = NULL;
4487
4488         if (entity->kind == ENTITY_VARIABLE) {
4489                 /* §6.7.5:22  array initializers for arrays with unknown size
4490                  * determine the array type size */
4491                 declaration->type            = env.type;
4492                 entity->variable.initializer = initializer;
4493         }
4494 }
4495
4496 /* parse rest of a declaration without any declarator */
4497 static void parse_anonymous_declaration_rest(
4498                 const declaration_specifiers_t *specifiers)
4499 {
4500         eat(';');
4501         anonymous_entity = NULL;
4502
4503         if (warning.other) {
4504                 if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4505                                 specifiers->thread_local) {
4506                         warningf(&specifiers->source_position,
4507                                  "useless storage class in empty declaration");
4508                 }
4509
4510                 type_t *type = specifiers->type;
4511                 switch (type->kind) {
4512                         case TYPE_COMPOUND_STRUCT:
4513                         case TYPE_COMPOUND_UNION: {
4514                                 if (type->compound.compound->base.symbol == NULL) {
4515                                         warningf(&specifiers->source_position,
4516                                                  "unnamed struct/union that defines no instances");
4517                                 }
4518                                 break;
4519                         }
4520
4521                         case TYPE_ENUM:
4522                                 break;
4523
4524                         default:
4525                                 warningf(&specifiers->source_position, "empty declaration");
4526                                 break;
4527                 }
4528         }
4529 }
4530
4531 static void check_variable_type_complete(entity_t *ent)
4532 {
4533         if (ent->kind != ENTITY_VARIABLE)
4534                 return;
4535
4536         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4537          *         type for the object shall be complete [...] */
4538         declaration_t *decl = &ent->declaration;
4539         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4540                         decl->storage_class == STORAGE_CLASS_STATIC)
4541                 return;
4542
4543         type_t *const orig_type = decl->type;
4544         type_t *const type      = skip_typeref(orig_type);
4545         if (!is_type_incomplete(type))
4546                 return;
4547
4548         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4549          * are given length one. */
4550         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4551                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4552                 return;
4553         }
4554
4555         errorf(&ent->base.source_position, "variable '%#T' has incomplete type",
4556                         orig_type, ent->base.symbol);
4557 }
4558
4559
4560 static void parse_declaration_rest(entity_t *ndeclaration,
4561                 const declaration_specifiers_t *specifiers,
4562                 parsed_declaration_func         finished_declaration,
4563                 declarator_flags_t              flags)
4564 {
4565         add_anchor_token(';');
4566         add_anchor_token(',');
4567         while (true) {
4568                 entity_t *entity = finished_declaration(ndeclaration, token.type == '=');
4569
4570                 if (token.type == '=') {
4571                         parse_init_declarator_rest(entity);
4572                 } else if (entity->kind == ENTITY_VARIABLE) {
4573                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4574                          * [...] where the extern specifier is explicitly used. */
4575                         declaration_t *decl = &entity->declaration;
4576                         if (decl->storage_class != STORAGE_CLASS_EXTERN) {
4577                                 type_t *type = decl->type;
4578                                 if (is_type_reference(skip_typeref(type))) {
4579                                         errorf(&entity->base.source_position,
4580                                                         "reference '%#T' must be initialized",
4581                                                         type, entity->base.symbol);
4582                                 }
4583                         }
4584                 }
4585
4586                 check_variable_type_complete(entity);
4587
4588                 if (!next_if(','))
4589                         break;
4590
4591                 add_anchor_token('=');
4592                 ndeclaration = parse_declarator(specifiers, flags);
4593                 rem_anchor_token('=');
4594         }
4595         expect(';', end_error);
4596
4597 end_error:
4598         anonymous_entity = NULL;
4599         rem_anchor_token(';');
4600         rem_anchor_token(',');
4601 }
4602
4603 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4604 {
4605         symbol_t *symbol = entity->base.symbol;
4606         if (symbol == NULL) {
4607                 errorf(HERE, "anonymous declaration not valid as function parameter");
4608                 return entity;
4609         }
4610
4611         assert(entity->base.namespc == NAMESPACE_NORMAL);
4612         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4613         if (previous_entity == NULL
4614                         || previous_entity->base.parent_scope != current_scope) {
4615                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4616                        symbol);
4617                 return entity;
4618         }
4619
4620         if (is_definition) {
4621                 errorf(HERE, "parameter '%Y' is initialised", entity->base.symbol);
4622         }
4623
4624         return record_entity(entity, false);
4625 }
4626
4627 static void parse_declaration(parsed_declaration_func finished_declaration,
4628                               declarator_flags_t      flags)
4629 {
4630         add_anchor_token(';');
4631         declaration_specifiers_t specifiers;
4632         parse_declaration_specifiers(&specifiers);
4633         rem_anchor_token(';');
4634
4635         if (token.type == ';') {
4636                 parse_anonymous_declaration_rest(&specifiers);
4637         } else {
4638                 entity_t *entity = parse_declarator(&specifiers, flags);
4639                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4640         }
4641 }
4642
4643 /* §6.5.2.2:6 */
4644 static type_t *get_default_promoted_type(type_t *orig_type)
4645 {
4646         type_t *result = orig_type;
4647
4648         type_t *type = skip_typeref(orig_type);
4649         if (is_type_integer(type)) {
4650                 result = promote_integer(type);
4651         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4652                 result = type_double;
4653         }
4654
4655         return result;
4656 }
4657
4658 static void parse_kr_declaration_list(entity_t *entity)
4659 {
4660         if (entity->kind != ENTITY_FUNCTION)
4661                 return;
4662
4663         type_t *type = skip_typeref(entity->declaration.type);
4664         assert(is_type_function(type));
4665         if (!type->function.kr_style_parameters)
4666                 return;
4667
4668         add_anchor_token('{');
4669
4670         /* push function parameters */
4671         size_t const  top       = environment_top();
4672         scope_t      *old_scope = scope_push(&entity->function.parameters);
4673
4674         entity_t *parameter = entity->function.parameters.entities;
4675         for ( ; parameter != NULL; parameter = parameter->base.next) {
4676                 assert(parameter->base.parent_scope == NULL);
4677                 parameter->base.parent_scope = current_scope;
4678                 environment_push(parameter);
4679         }
4680
4681         /* parse declaration list */
4682         for (;;) {
4683                 switch (token.type) {
4684                         DECLARATION_START
4685                         case T___extension__:
4686                         /* This covers symbols, which are no type, too, and results in
4687                          * better error messages.  The typical cases are misspelled type
4688                          * names and missing includes. */
4689                         case T_IDENTIFIER:
4690                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4691                                 break;
4692                         default:
4693                                 goto decl_list_end;
4694                 }
4695         }
4696 decl_list_end:
4697
4698         /* pop function parameters */
4699         assert(current_scope == &entity->function.parameters);
4700         scope_pop(old_scope);
4701         environment_pop_to(top);
4702
4703         /* update function type */
4704         type_t *new_type = duplicate_type(type);
4705
4706         function_parameter_t  *parameters = NULL;
4707         function_parameter_t **anchor     = &parameters;
4708
4709         /* did we have an earlier prototype? */
4710         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4711         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4712                 proto_type = NULL;
4713
4714         function_parameter_t *proto_parameter = NULL;
4715         if (proto_type != NULL) {
4716                 type_t *proto_type_type = proto_type->declaration.type;
4717                 proto_parameter         = proto_type_type->function.parameters;
4718                 /* If a K&R function definition has a variadic prototype earlier, then
4719                  * make the function definition variadic, too. This should conform to
4720                  * §6.7.5.3:15 and §6.9.1:8. */
4721                 new_type->function.variadic = proto_type_type->function.variadic;
4722         } else {
4723                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4724                  * prototype */
4725                 new_type->function.unspecified_parameters = true;
4726         }
4727
4728         bool need_incompatible_warning = false;
4729         parameter = entity->function.parameters.entities;
4730         for (; parameter != NULL; parameter = parameter->base.next,
4731                         proto_parameter =
4732                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4733                 if (parameter->kind != ENTITY_PARAMETER)
4734                         continue;
4735
4736                 type_t *parameter_type = parameter->declaration.type;
4737                 if (parameter_type == NULL) {
4738                         if (strict_mode) {
4739                                 errorf(HERE, "no type specified for function parameter '%Y'",
4740                                        parameter->base.symbol);
4741                                 parameter_type = type_error_type;
4742                         } else {
4743                                 if (warning.implicit_int) {
4744                                         warningf(HERE, "no type specified for function parameter '%Y', using 'int'",
4745                                                  parameter->base.symbol);
4746                                 }
4747                                 parameter_type = type_int;
4748                         }
4749                         parameter->declaration.type = parameter_type;
4750                 }
4751
4752                 semantic_parameter_incomplete(parameter);
4753
4754                 /* we need the default promoted types for the function type */
4755                 type_t *not_promoted = parameter_type;
4756                 parameter_type       = get_default_promoted_type(parameter_type);
4757
4758                 /* gcc special: if the type of the prototype matches the unpromoted
4759                  * type don't promote */
4760                 if (!strict_mode && proto_parameter != NULL) {
4761                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4762                         type_t *promo_skip   = skip_typeref(parameter_type);
4763                         type_t *param_skip   = skip_typeref(not_promoted);
4764                         if (!types_compatible(proto_p_type, promo_skip)
4765                                 && types_compatible(proto_p_type, param_skip)) {
4766                                 /* don't promote */
4767                                 need_incompatible_warning = true;
4768                                 parameter_type = not_promoted;
4769                         }
4770                 }
4771                 function_parameter_t *const parameter
4772                         = allocate_parameter(parameter_type);
4773
4774                 *anchor = parameter;
4775                 anchor  = &parameter->next;
4776         }
4777
4778         new_type->function.parameters = parameters;
4779         new_type = identify_new_type(new_type);
4780
4781         if (warning.other && need_incompatible_warning) {
4782                 type_t *proto_type_type = proto_type->declaration.type;
4783                 warningf(HERE,
4784                          "declaration '%#T' is incompatible with '%#T' (declared %P)",
4785                          proto_type_type, proto_type->base.symbol,
4786                          new_type, entity->base.symbol,
4787                          &proto_type->base.source_position);
4788         }
4789
4790         entity->declaration.type = new_type;
4791
4792         rem_anchor_token('{');
4793 }
4794
4795 static bool first_err = true;
4796
4797 /**
4798  * When called with first_err set, prints the name of the current function,
4799  * else does noting.
4800  */
4801 static void print_in_function(void)
4802 {
4803         if (first_err) {
4804                 first_err = false;
4805                 diagnosticf("%s: In function '%Y':\n",
4806                             current_function->base.base.source_position.input_name,
4807                             current_function->base.base.symbol);
4808         }
4809 }
4810
4811 /**
4812  * Check if all labels are defined in the current function.
4813  * Check if all labels are used in the current function.
4814  */
4815 static void check_labels(void)
4816 {
4817         for (const goto_statement_t *goto_statement = goto_first;
4818             goto_statement != NULL;
4819             goto_statement = goto_statement->next) {
4820                 /* skip computed gotos */
4821                 if (goto_statement->expression != NULL)
4822                         continue;
4823
4824                 label_t *label = goto_statement->label;
4825
4826                 label->used = true;
4827                 if (label->base.source_position.input_name == NULL) {
4828                         print_in_function();
4829                         errorf(&goto_statement->base.source_position,
4830                                "label '%Y' used but not defined", label->base.symbol);
4831                  }
4832         }
4833
4834         if (warning.unused_label) {
4835                 for (const label_statement_t *label_statement = label_first;
4836                          label_statement != NULL;
4837                          label_statement = label_statement->next) {
4838                         label_t *label = label_statement->label;
4839
4840                         if (! label->used) {
4841                                 print_in_function();
4842                                 warningf(&label_statement->base.source_position,
4843                                          "label '%Y' defined but not used", label->base.symbol);
4844                         }
4845                 }
4846         }
4847 }
4848
4849 static void warn_unused_entity(entity_t *entity, entity_t *last)
4850 {
4851         entity_t const *const end = last != NULL ? last->base.next : NULL;
4852         for (; entity != end; entity = entity->base.next) {
4853                 if (!is_declaration(entity))
4854                         continue;
4855
4856                 declaration_t *declaration = &entity->declaration;
4857                 if (declaration->implicit)
4858                         continue;
4859
4860                 if (!declaration->used) {
4861                         print_in_function();
4862                         const char *what = get_entity_kind_name(entity->kind);
4863                         warningf(&entity->base.source_position, "%s '%Y' is unused",
4864                                  what, entity->base.symbol);
4865                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4866                         print_in_function();
4867                         const char *what = get_entity_kind_name(entity->kind);
4868                         warningf(&entity->base.source_position, "%s '%Y' is never read",
4869                                  what, entity->base.symbol);
4870                 }
4871         }
4872 }
4873
4874 static void check_unused_variables(statement_t *const stmt, void *const env)
4875 {
4876         (void)env;
4877
4878         switch (stmt->kind) {
4879                 case STATEMENT_DECLARATION: {
4880                         declaration_statement_t const *const decls = &stmt->declaration;
4881                         warn_unused_entity(decls->declarations_begin,
4882                                            decls->declarations_end);
4883                         return;
4884                 }
4885
4886                 case STATEMENT_FOR:
4887                         warn_unused_entity(stmt->fors.scope.entities, NULL);
4888                         return;
4889
4890                 default:
4891                         return;
4892         }
4893 }
4894
4895 /**
4896  * Check declarations of current_function for unused entities.
4897  */
4898 static void check_declarations(void)
4899 {
4900         if (warning.unused_parameter) {
4901                 const scope_t *scope = &current_function->parameters;
4902
4903                 /* do not issue unused warnings for main */
4904                 if (!is_sym_main(current_function->base.base.symbol)) {
4905                         warn_unused_entity(scope->entities, NULL);
4906                 }
4907         }
4908         if (warning.unused_variable) {
4909                 walk_statements(current_function->statement, check_unused_variables,
4910                                 NULL);
4911         }
4912 }
4913
4914 static int determine_truth(expression_t const* const cond)
4915 {
4916         return
4917                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4918                 fold_constant_to_bool(cond)                         ? 1 :
4919                 -1;
4920 }
4921
4922 static void check_reachable(statement_t *);
4923 static bool reaches_end;
4924
4925 static bool expression_returns(expression_t const *const expr)
4926 {
4927         switch (expr->kind) {
4928                 case EXPR_CALL: {
4929                         expression_t const *const func = expr->call.function;
4930                         if (func->kind == EXPR_REFERENCE) {
4931                                 entity_t *entity = func->reference.entity;
4932                                 if (entity->kind == ENTITY_FUNCTION
4933                                                 && entity->declaration.modifiers & DM_NORETURN)
4934                                         return false;
4935                         }
4936
4937                         if (!expression_returns(func))
4938                                 return false;
4939
4940                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4941                                 if (!expression_returns(arg->expression))
4942                                         return false;
4943                         }
4944
4945                         return true;
4946                 }
4947
4948                 case EXPR_REFERENCE:
4949                 case EXPR_REFERENCE_ENUM_VALUE:
4950                 EXPR_LITERAL_CASES
4951                 case EXPR_STRING_LITERAL:
4952                 case EXPR_WIDE_STRING_LITERAL:
4953                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4954                 case EXPR_LABEL_ADDRESS:
4955                 case EXPR_CLASSIFY_TYPE:
4956                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4957                 case EXPR_ALIGNOF:
4958                 case EXPR_FUNCNAME:
4959                 case EXPR_BUILTIN_CONSTANT_P:
4960                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4961                 case EXPR_OFFSETOF:
4962                 case EXPR_INVALID:
4963                         return true;
4964
4965                 case EXPR_STATEMENT: {
4966                         bool old_reaches_end = reaches_end;
4967                         reaches_end = false;
4968                         check_reachable(expr->statement.statement);
4969                         bool returns = reaches_end;
4970                         reaches_end = old_reaches_end;
4971                         return returns;
4972                 }
4973
4974                 case EXPR_CONDITIONAL:
4975                         // TODO handle constant expression
4976
4977                         if (!expression_returns(expr->conditional.condition))
4978                                 return false;
4979
4980                         if (expr->conditional.true_expression != NULL
4981                                         && expression_returns(expr->conditional.true_expression))
4982                                 return true;
4983
4984                         return expression_returns(expr->conditional.false_expression);
4985
4986                 case EXPR_SELECT:
4987                         return expression_returns(expr->select.compound);
4988
4989                 case EXPR_ARRAY_ACCESS:
4990                         return
4991                                 expression_returns(expr->array_access.array_ref) &&
4992                                 expression_returns(expr->array_access.index);
4993
4994                 case EXPR_VA_START:
4995                         return expression_returns(expr->va_starte.ap);
4996
4997                 case EXPR_VA_ARG:
4998                         return expression_returns(expr->va_arge.ap);
4999
5000                 case EXPR_VA_COPY:
5001                         return expression_returns(expr->va_copye.src);
5002
5003                 EXPR_UNARY_CASES_MANDATORY
5004                         return expression_returns(expr->unary.value);
5005
5006                 case EXPR_UNARY_THROW:
5007                         return false;
5008
5009                 EXPR_BINARY_CASES
5010                         // TODO handle constant lhs of && and ||
5011                         return
5012                                 expression_returns(expr->binary.left) &&
5013                                 expression_returns(expr->binary.right);
5014
5015                 case EXPR_UNKNOWN:
5016                         break;
5017         }
5018
5019         panic("unhandled expression");
5020 }
5021
5022 static bool initializer_returns(initializer_t const *const init)
5023 {
5024         switch (init->kind) {
5025                 case INITIALIZER_VALUE:
5026                         return expression_returns(init->value.value);
5027
5028                 case INITIALIZER_LIST: {
5029                         initializer_t * const*       i       = init->list.initializers;
5030                         initializer_t * const* const end     = i + init->list.len;
5031                         bool                         returns = true;
5032                         for (; i != end; ++i) {
5033                                 if (!initializer_returns(*i))
5034                                         returns = false;
5035                         }
5036                         return returns;
5037                 }
5038
5039                 case INITIALIZER_STRING:
5040                 case INITIALIZER_WIDE_STRING:
5041                 case INITIALIZER_DESIGNATOR: // designators have no payload
5042                         return true;
5043         }
5044         panic("unhandled initializer");
5045 }
5046
5047 static bool noreturn_candidate;
5048
5049 static void check_reachable(statement_t *const stmt)
5050 {
5051         if (stmt->base.reachable)
5052                 return;
5053         if (stmt->kind != STATEMENT_DO_WHILE)
5054                 stmt->base.reachable = true;
5055
5056         statement_t *last = stmt;
5057         statement_t *next;
5058         switch (stmt->kind) {
5059                 case STATEMENT_INVALID:
5060                 case STATEMENT_EMPTY:
5061                 case STATEMENT_ASM:
5062                         next = stmt->base.next;
5063                         break;
5064
5065                 case STATEMENT_DECLARATION: {
5066                         declaration_statement_t const *const decl = &stmt->declaration;
5067                         entity_t                const *      ent  = decl->declarations_begin;
5068                         entity_t                const *const last = decl->declarations_end;
5069                         if (ent != NULL) {
5070                                 for (;; ent = ent->base.next) {
5071                                         if (ent->kind                 == ENTITY_VARIABLE &&
5072                                                         ent->variable.initializer != NULL            &&
5073                                                         !initializer_returns(ent->variable.initializer)) {
5074                                                 return;
5075                                         }
5076                                         if (ent == last)
5077                                                 break;
5078                                 }
5079                         }
5080                         next = stmt->base.next;
5081                         break;
5082                 }
5083
5084                 case STATEMENT_COMPOUND:
5085                         next = stmt->compound.statements;
5086                         if (next == NULL)
5087                                 next = stmt->base.next;
5088                         break;
5089
5090                 case STATEMENT_RETURN: {
5091                         expression_t const *const val = stmt->returns.value;
5092                         if (val == NULL || expression_returns(val))
5093                                 noreturn_candidate = false;
5094                         return;
5095                 }
5096
5097                 case STATEMENT_IF: {
5098                         if_statement_t const *const ifs  = &stmt->ifs;
5099                         expression_t   const *const cond = ifs->condition;
5100
5101                         if (!expression_returns(cond))
5102                                 return;
5103
5104                         int const val = determine_truth(cond);
5105
5106                         if (val >= 0)
5107                                 check_reachable(ifs->true_statement);
5108
5109                         if (val > 0)
5110                                 return;
5111
5112                         if (ifs->false_statement != NULL) {
5113                                 check_reachable(ifs->false_statement);
5114                                 return;
5115                         }
5116
5117                         next = stmt->base.next;
5118                         break;
5119                 }
5120
5121                 case STATEMENT_SWITCH: {
5122                         switch_statement_t const *const switchs = &stmt->switchs;
5123                         expression_t       const *const expr    = switchs->expression;
5124
5125                         if (!expression_returns(expr))
5126                                 return;
5127
5128                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
5129                                 long                    const val      = fold_constant_to_int(expr);
5130                                 case_label_statement_t *      defaults = NULL;
5131                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5132                                         if (i->expression == NULL) {
5133                                                 defaults = i;
5134                                                 continue;
5135                                         }
5136
5137                                         if (i->first_case <= val && val <= i->last_case) {
5138                                                 check_reachable((statement_t*)i);
5139                                                 return;
5140                                         }
5141                                 }
5142
5143                                 if (defaults != NULL) {
5144                                         check_reachable((statement_t*)defaults);
5145                                         return;
5146                                 }
5147                         } else {
5148                                 bool has_default = false;
5149                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
5150                                         if (i->expression == NULL)
5151                                                 has_default = true;
5152
5153                                         check_reachable((statement_t*)i);
5154                                 }
5155
5156                                 if (has_default)
5157                                         return;
5158                         }
5159
5160                         next = stmt->base.next;
5161                         break;
5162                 }
5163
5164                 case STATEMENT_EXPRESSION: {
5165                         /* Check for noreturn function call */
5166                         expression_t const *const expr = stmt->expression.expression;
5167                         if (!expression_returns(expr))
5168                                 return;
5169
5170                         next = stmt->base.next;
5171                         break;
5172                 }
5173
5174                 case STATEMENT_CONTINUE:
5175                         for (statement_t *parent = stmt;;) {
5176                                 parent = parent->base.parent;
5177                                 if (parent == NULL) /* continue not within loop */
5178                                         return;
5179
5180                                 next = parent;
5181                                 switch (parent->kind) {
5182                                         case STATEMENT_WHILE:    goto continue_while;
5183                                         case STATEMENT_DO_WHILE: goto continue_do_while;
5184                                         case STATEMENT_FOR:      goto continue_for;
5185
5186                                         default: break;
5187                                 }
5188                         }
5189
5190                 case STATEMENT_BREAK:
5191                         for (statement_t *parent = stmt;;) {
5192                                 parent = parent->base.parent;
5193                                 if (parent == NULL) /* break not within loop/switch */
5194                                         return;
5195
5196                                 switch (parent->kind) {
5197                                         case STATEMENT_SWITCH:
5198                                         case STATEMENT_WHILE:
5199                                         case STATEMENT_DO_WHILE:
5200                                         case STATEMENT_FOR:
5201                                                 last = parent;
5202                                                 next = parent->base.next;
5203                                                 goto found_break_parent;
5204
5205                                         default: break;
5206                                 }
5207                         }
5208 found_break_parent:
5209                         break;
5210
5211                 case STATEMENT_GOTO:
5212                         if (stmt->gotos.expression) {
5213                                 if (!expression_returns(stmt->gotos.expression))
5214                                         return;
5215
5216                                 statement_t *parent = stmt->base.parent;
5217                                 if (parent == NULL) /* top level goto */
5218                                         return;
5219                                 next = parent;
5220                         } else {
5221                                 next = stmt->gotos.label->statement;
5222                                 if (next == NULL) /* missing label */
5223                                         return;
5224                         }
5225                         break;
5226
5227                 case STATEMENT_LABEL:
5228                         next = stmt->label.statement;
5229                         break;
5230
5231                 case STATEMENT_CASE_LABEL:
5232                         next = stmt->case_label.statement;
5233                         break;
5234
5235                 case STATEMENT_WHILE: {
5236                         while_statement_t const *const whiles = &stmt->whiles;
5237                         expression_t      const *const cond   = whiles->condition;
5238
5239                         if (!expression_returns(cond))
5240                                 return;
5241
5242                         int const val = determine_truth(cond);
5243
5244                         if (val >= 0)
5245                                 check_reachable(whiles->body);
5246
5247                         if (val > 0)
5248                                 return;
5249
5250                         next = stmt->base.next;
5251                         break;
5252                 }
5253
5254                 case STATEMENT_DO_WHILE:
5255                         next = stmt->do_while.body;
5256                         break;
5257
5258                 case STATEMENT_FOR: {
5259                         for_statement_t *const fors = &stmt->fors;
5260
5261                         if (fors->condition_reachable)
5262                                 return;
5263                         fors->condition_reachable = true;
5264
5265                         expression_t const *const cond = fors->condition;
5266
5267                         int val;
5268                         if (cond == NULL) {
5269                                 val = 1;
5270                         } else if (expression_returns(cond)) {
5271                                 val = determine_truth(cond);
5272                         } else {
5273                                 return;
5274                         }
5275
5276                         if (val >= 0)
5277                                 check_reachable(fors->body);
5278
5279                         if (val > 0)
5280                                 return;
5281
5282                         next = stmt->base.next;
5283                         break;
5284                 }
5285
5286                 case STATEMENT_MS_TRY: {
5287                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
5288                         check_reachable(ms_try->try_statement);
5289                         next = ms_try->final_statement;
5290                         break;
5291                 }
5292
5293                 case STATEMENT_LEAVE: {
5294                         statement_t *parent = stmt;
5295                         for (;;) {
5296                                 parent = parent->base.parent;
5297                                 if (parent == NULL) /* __leave not within __try */
5298                                         return;
5299
5300                                 if (parent->kind == STATEMENT_MS_TRY) {
5301                                         last = parent;
5302                                         next = parent->ms_try.final_statement;
5303                                         break;
5304                                 }
5305                         }
5306                         break;
5307                 }
5308
5309                 default:
5310                         panic("invalid statement kind");
5311         }
5312
5313         while (next == NULL) {
5314                 next = last->base.parent;
5315                 if (next == NULL) {
5316                         noreturn_candidate = false;
5317
5318                         type_t *const type = skip_typeref(current_function->base.type);
5319                         assert(is_type_function(type));
5320                         type_t *const ret  = skip_typeref(type->function.return_type);
5321                         if (warning.return_type                    &&
5322                             !is_type_atomic(ret, ATOMIC_TYPE_VOID) &&
5323                             is_type_valid(ret)                     &&
5324                             !is_sym_main(current_function->base.base.symbol)) {
5325                                 warningf(&stmt->base.source_position,
5326                                          "control reaches end of non-void function");
5327                         }
5328                         return;
5329                 }
5330
5331                 switch (next->kind) {
5332                         case STATEMENT_INVALID:
5333                         case STATEMENT_EMPTY:
5334                         case STATEMENT_DECLARATION:
5335                         case STATEMENT_EXPRESSION:
5336                         case STATEMENT_ASM:
5337                         case STATEMENT_RETURN:
5338                         case STATEMENT_CONTINUE:
5339                         case STATEMENT_BREAK:
5340                         case STATEMENT_GOTO:
5341                         case STATEMENT_LEAVE:
5342                                 panic("invalid control flow in function");
5343
5344                         case STATEMENT_COMPOUND:
5345                                 if (next->compound.stmt_expr) {
5346                                         reaches_end = true;
5347                                         return;
5348                                 }
5349                                 /* FALLTHROUGH */
5350                         case STATEMENT_IF:
5351                         case STATEMENT_SWITCH:
5352                         case STATEMENT_LABEL:
5353                         case STATEMENT_CASE_LABEL:
5354                                 last = next;
5355                                 next = next->base.next;
5356                                 break;
5357
5358                         case STATEMENT_WHILE: {
5359 continue_while:
5360                                 if (next->base.reachable)
5361                                         return;
5362                                 next->base.reachable = true;
5363
5364                                 while_statement_t const *const whiles = &next->whiles;
5365                                 expression_t      const *const cond   = whiles->condition;
5366
5367                                 if (!expression_returns(cond))
5368                                         return;
5369
5370                                 int const val = determine_truth(cond);
5371
5372                                 if (val >= 0)
5373                                         check_reachable(whiles->body);
5374
5375                                 if (val > 0)
5376                                         return;
5377
5378                                 last = next;
5379                                 next = next->base.next;
5380                                 break;
5381                         }
5382
5383                         case STATEMENT_DO_WHILE: {
5384 continue_do_while:
5385                                 if (next->base.reachable)
5386                                         return;
5387                                 next->base.reachable = true;
5388
5389                                 do_while_statement_t const *const dw   = &next->do_while;
5390                                 expression_t         const *const cond = dw->condition;
5391
5392                                 if (!expression_returns(cond))
5393                                         return;
5394
5395                                 int const val = determine_truth(cond);
5396
5397                                 if (val >= 0)
5398                                         check_reachable(dw->body);
5399
5400                                 if (val > 0)
5401                                         return;
5402
5403                                 last = next;
5404                                 next = next->base.next;
5405                                 break;
5406                         }
5407
5408                         case STATEMENT_FOR: {
5409 continue_for:;
5410                                 for_statement_t *const fors = &next->fors;
5411
5412                                 fors->step_reachable = true;
5413
5414                                 if (fors->condition_reachable)
5415                                         return;
5416                                 fors->condition_reachable = true;
5417
5418                                 expression_t const *const cond = fors->condition;
5419
5420                                 int val;
5421                                 if (cond == NULL) {
5422                                         val = 1;
5423                                 } else if (expression_returns(cond)) {
5424                                         val = determine_truth(cond);
5425                                 } else {
5426                                         return;
5427                                 }
5428
5429                                 if (val >= 0)
5430                                         check_reachable(fors->body);
5431
5432                                 if (val > 0)
5433                                         return;
5434
5435                                 last = next;
5436                                 next = next->base.next;
5437                                 break;
5438                         }
5439
5440                         case STATEMENT_MS_TRY:
5441                                 last = next;
5442                                 next = next->ms_try.final_statement;
5443                                 break;
5444                 }
5445         }
5446
5447         check_reachable(next);
5448 }
5449
5450 static void check_unreachable(statement_t* const stmt, void *const env)
5451 {
5452         (void)env;
5453
5454         switch (stmt->kind) {
5455                 case STATEMENT_DO_WHILE:
5456                         if (!stmt->base.reachable) {
5457                                 expression_t const *const cond = stmt->do_while.condition;
5458                                 if (determine_truth(cond) >= 0) {
5459                                         warningf(&cond->base.source_position,
5460                                                  "condition of do-while-loop is unreachable");
5461                                 }
5462                         }
5463                         return;
5464
5465                 case STATEMENT_FOR: {
5466                         for_statement_t const* const fors = &stmt->fors;
5467
5468                         // if init and step are unreachable, cond is unreachable, too
5469                         if (!stmt->base.reachable && !fors->step_reachable) {
5470                                 warningf(&stmt->base.source_position, "statement is unreachable");
5471                         } else {
5472                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5473                                         warningf(&fors->initialisation->base.source_position,
5474                                                  "initialisation of for-statement is unreachable");
5475                                 }
5476
5477                                 if (!fors->condition_reachable && fors->condition != NULL) {
5478                                         warningf(&fors->condition->base.source_position,
5479                                                  "condition of for-statement is unreachable");
5480                                 }
5481
5482                                 if (!fors->step_reachable && fors->step != NULL) {
5483                                         warningf(&fors->step->base.source_position,
5484                                                  "step of for-statement is unreachable");
5485                                 }
5486                         }
5487                         return;
5488                 }
5489
5490                 case STATEMENT_COMPOUND:
5491                         if (stmt->compound.statements != NULL)
5492                                 return;
5493                         goto warn_unreachable;
5494
5495                 case STATEMENT_DECLARATION: {
5496                         /* Only warn if there is at least one declarator with an initializer.
5497                          * This typically occurs in switch statements. */
5498                         declaration_statement_t const *const decl = &stmt->declaration;
5499                         entity_t                const *      ent  = decl->declarations_begin;
5500                         entity_t                const *const last = decl->declarations_end;
5501                         if (ent != NULL) {
5502                                 for (;; ent = ent->base.next) {
5503                                         if (ent->kind                 == ENTITY_VARIABLE &&
5504                                                         ent->variable.initializer != NULL) {
5505                                                 goto warn_unreachable;
5506                                         }
5507                                         if (ent == last)
5508                                                 return;
5509                                 }
5510                         }
5511                 }
5512
5513                 default:
5514 warn_unreachable:
5515                         if (!stmt->base.reachable)
5516                                 warningf(&stmt->base.source_position, "statement is unreachable");
5517                         return;
5518         }
5519 }
5520
5521 static void parse_external_declaration(void)
5522 {
5523         /* function-definitions and declarations both start with declaration
5524          * specifiers */
5525         add_anchor_token(';');
5526         declaration_specifiers_t specifiers;
5527         parse_declaration_specifiers(&specifiers);
5528         rem_anchor_token(';');
5529
5530         /* must be a declaration */
5531         if (token.type == ';') {
5532                 parse_anonymous_declaration_rest(&specifiers);
5533                 return;
5534         }
5535
5536         add_anchor_token(',');
5537         add_anchor_token('=');
5538         add_anchor_token(';');
5539         add_anchor_token('{');
5540
5541         /* declarator is common to both function-definitions and declarations */
5542         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5543
5544         rem_anchor_token('{');
5545         rem_anchor_token(';');
5546         rem_anchor_token('=');
5547         rem_anchor_token(',');
5548
5549         /* must be a declaration */
5550         switch (token.type) {
5551                 case ',':
5552                 case ';':
5553                 case '=':
5554                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5555                                         DECL_FLAGS_NONE);
5556                         return;
5557         }
5558
5559         /* must be a function definition */
5560         parse_kr_declaration_list(ndeclaration);
5561
5562         if (token.type != '{') {
5563                 parse_error_expected("while parsing function definition", '{', NULL);
5564                 eat_until_matching_token(';');
5565                 return;
5566         }
5567
5568         assert(is_declaration(ndeclaration));
5569         type_t *const orig_type = ndeclaration->declaration.type;
5570         type_t *      type      = skip_typeref(orig_type);
5571
5572         if (!is_type_function(type)) {
5573                 if (is_type_valid(type)) {
5574                         errorf(HERE, "declarator '%#T' has a body but is not a function type",
5575                                type, ndeclaration->base.symbol);
5576                 }
5577                 eat_block();
5578                 return;
5579         } else if (is_typeref(orig_type)) {
5580                 /* §6.9.1:2 */
5581                 errorf(&ndeclaration->base.source_position,
5582                                 "type of function definition '%#T' is a typedef",
5583                                 orig_type, ndeclaration->base.symbol);
5584         }
5585
5586         if (warning.aggregate_return &&
5587             is_type_compound(skip_typeref(type->function.return_type))) {
5588                 warningf(&ndeclaration->base.source_position, "function '%Y' returns an aggregate",
5589                          ndeclaration->base.symbol);
5590         }
5591         if (warning.traditional && !type->function.unspecified_parameters) {
5592                 warningf(&ndeclaration->base.source_position, "traditional C rejects ISO C style function definition of function '%Y'",
5593                         ndeclaration->base.symbol);
5594         }
5595         if (warning.old_style_definition && type->function.unspecified_parameters) {
5596                 warningf(&ndeclaration->base.source_position, "old-style function definition '%Y'",
5597                         ndeclaration->base.symbol);
5598         }
5599
5600         /* §6.7.5.3:14 a function definition with () means no
5601          * parameters (and not unspecified parameters) */
5602         if (type->function.unspecified_parameters &&
5603                         type->function.parameters == NULL) {
5604                 type_t *copy                          = duplicate_type(type);
5605                 copy->function.unspecified_parameters = false;
5606                 type                                  = identify_new_type(copy);
5607
5608                 ndeclaration->declaration.type = type;
5609         }
5610
5611         entity_t *const entity = record_entity(ndeclaration, true);
5612         assert(entity->kind == ENTITY_FUNCTION);
5613         assert(ndeclaration->kind == ENTITY_FUNCTION);
5614
5615         function_t *const function = &entity->function;
5616         if (ndeclaration != entity) {
5617                 function->parameters = ndeclaration->function.parameters;
5618         }
5619         assert(is_declaration(entity));
5620         type = skip_typeref(entity->declaration.type);
5621
5622         /* push function parameters and switch scope */
5623         size_t const  top       = environment_top();
5624         scope_t      *old_scope = scope_push(&function->parameters);
5625
5626         entity_t *parameter = function->parameters.entities;
5627         for (; parameter != NULL; parameter = parameter->base.next) {
5628                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5629                         parameter->base.parent_scope = current_scope;
5630                 }
5631                 assert(parameter->base.parent_scope == NULL
5632                                 || parameter->base.parent_scope == current_scope);
5633                 parameter->base.parent_scope = current_scope;
5634                 if (parameter->base.symbol == NULL) {
5635                         errorf(&parameter->base.source_position, "parameter name omitted");
5636                         continue;
5637                 }
5638                 environment_push(parameter);
5639         }
5640
5641         if (function->statement != NULL) {
5642                 parser_error_multiple_definition(entity, HERE);
5643                 eat_block();
5644         } else {
5645                 /* parse function body */
5646                 int         label_stack_top      = label_top();
5647                 function_t *old_current_function = current_function;
5648                 entity_t   *old_current_entity   = current_entity;
5649                 current_function                 = function;
5650                 current_entity                   = entity;
5651                 current_parent                   = NULL;
5652
5653                 goto_first   = NULL;
5654                 goto_anchor  = &goto_first;
5655                 label_first  = NULL;
5656                 label_anchor = &label_first;
5657
5658                 statement_t *const body = parse_compound_statement(false);
5659                 function->statement = body;
5660                 first_err = true;
5661                 check_labels();
5662                 check_declarations();
5663                 if (warning.return_type      ||
5664                     warning.unreachable_code ||
5665                     (warning.missing_noreturn
5666                      && !(function->base.modifiers & DM_NORETURN))) {
5667                         noreturn_candidate = true;
5668                         check_reachable(body);
5669                         if (warning.unreachable_code)
5670                                 walk_statements(body, check_unreachable, NULL);
5671                         if (warning.missing_noreturn &&
5672                             noreturn_candidate       &&
5673                             !(function->base.modifiers & DM_NORETURN)) {
5674                                 warningf(&body->base.source_position,
5675                                          "function '%#T' is candidate for attribute 'noreturn'",
5676                                          type, entity->base.symbol);
5677                         }
5678                 }
5679
5680                 assert(current_parent   == NULL);
5681                 assert(current_function == function);
5682                 assert(current_entity   == entity);
5683                 current_entity   = old_current_entity;
5684                 current_function = old_current_function;
5685                 label_pop_to(label_stack_top);
5686         }
5687
5688         assert(current_scope == &function->parameters);
5689         scope_pop(old_scope);
5690         environment_pop_to(top);
5691 }
5692
5693 static type_t *make_bitfield_type(type_t *base_type, expression_t *size,
5694                                   source_position_t *source_position,
5695                                   const symbol_t *symbol)
5696 {
5697         type_t *type = allocate_type_zero(TYPE_BITFIELD);
5698
5699         type->bitfield.base_type       = base_type;
5700         type->bitfield.size_expression = size;
5701
5702         il_size_t bit_size;
5703         type_t *skipped_type = skip_typeref(base_type);
5704         if (!is_type_integer(skipped_type)) {
5705                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5706                        base_type);
5707                 bit_size = 0;
5708         } else {
5709                 bit_size = get_type_size(base_type) * 8;
5710         }
5711
5712         if (is_constant_expression(size) == EXPR_CLASS_CONSTANT) {
5713                 long v = fold_constant_to_int(size);
5714                 const symbol_t *user_symbol = symbol == NULL ? sym_anonymous : symbol;
5715
5716                 if (v < 0) {
5717                         errorf(source_position, "negative width in bit-field '%Y'",
5718                                user_symbol);
5719                 } else if (v == 0 && symbol != NULL) {
5720                         errorf(source_position, "zero width for bit-field '%Y'",
5721                                user_symbol);
5722                 } else if (bit_size > 0 && (il_size_t)v > bit_size) {
5723                         errorf(source_position, "width of '%Y' exceeds its type",
5724                                user_symbol);
5725                 } else {
5726                         type->bitfield.bit_size = v;
5727                 }
5728         }
5729
5730         return type;
5731 }
5732
5733 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5734 {
5735         entity_t *iter = compound->members.entities;
5736         for (; iter != NULL; iter = iter->base.next) {
5737                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5738                         continue;
5739
5740                 if (iter->base.symbol == symbol) {
5741                         return iter;
5742                 } else if (iter->base.symbol == NULL) {
5743                         /* search in anonymous structs and unions */
5744                         type_t *type = skip_typeref(iter->declaration.type);
5745                         if (is_type_compound(type)) {
5746                                 if (find_compound_entry(type->compound.compound, symbol)
5747                                                 != NULL)
5748                                         return iter;
5749                         }
5750                         continue;
5751                 }
5752         }
5753
5754         return NULL;
5755 }
5756
5757 static void check_deprecated(const source_position_t *source_position,
5758                              const entity_t *entity)
5759 {
5760         if (!warning.deprecated_declarations)
5761                 return;
5762         if (!is_declaration(entity))
5763                 return;
5764         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5765                 return;
5766
5767         char const *const prefix = get_entity_kind_name(entity->kind);
5768         const char *deprecated_string
5769                         = get_deprecated_string(entity->declaration.attributes);
5770         if (deprecated_string != NULL) {
5771                 warningf(source_position, "%s '%Y' is deprecated (declared %P): \"%s\"",
5772                                  prefix, entity->base.symbol, &entity->base.source_position,
5773                                  deprecated_string);
5774         } else {
5775                 warningf(source_position, "%s '%Y' is deprecated (declared %P)", prefix,
5776                                  entity->base.symbol, &entity->base.source_position);
5777         }
5778 }
5779
5780
5781 static expression_t *create_select(const source_position_t *pos,
5782                                    expression_t *addr,
5783                                    type_qualifiers_t qualifiers,
5784                                                                    entity_t *entry)
5785 {
5786         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5787
5788         check_deprecated(pos, entry);
5789
5790         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5791         select->select.compound       = addr;
5792         select->select.compound_entry = entry;
5793
5794         type_t *entry_type = entry->declaration.type;
5795         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5796
5797         /* we always do the auto-type conversions; the & and sizeof parser contains
5798          * code to revert this! */
5799         select->base.type = automatic_type_conversion(res_type);
5800         if (res_type->kind == TYPE_BITFIELD) {
5801                 select->base.type = res_type->bitfield.base_type;
5802         }
5803
5804         return select;
5805 }
5806
5807 /**
5808  * Find entry with symbol in compound. Search anonymous structs and unions and
5809  * creates implicit select expressions for them.
5810  * Returns the adress for the innermost compound.
5811  */
5812 static expression_t *find_create_select(const source_position_t *pos,
5813                                         expression_t *addr,
5814                                         type_qualifiers_t qualifiers,
5815                                         compound_t *compound, symbol_t *symbol)
5816 {
5817         entity_t *iter = compound->members.entities;
5818         for (; iter != NULL; iter = iter->base.next) {
5819                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5820                         continue;
5821
5822                 symbol_t *iter_symbol = iter->base.symbol;
5823                 if (iter_symbol == NULL) {
5824                         type_t *type = iter->declaration.type;
5825                         if (type->kind != TYPE_COMPOUND_STRUCT
5826                                         && type->kind != TYPE_COMPOUND_UNION)
5827                                 continue;
5828
5829                         compound_t *sub_compound = type->compound.compound;
5830
5831                         if (find_compound_entry(sub_compound, symbol) == NULL)
5832                                 continue;
5833
5834                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5835                         sub_addr->base.source_position = *pos;
5836                         sub_addr->select.implicit      = true;
5837                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5838                                                   symbol);
5839                 }
5840
5841                 if (iter_symbol == symbol) {
5842                         return create_select(pos, addr, qualifiers, iter);
5843                 }
5844         }
5845
5846         return NULL;
5847 }
5848
5849 static void parse_compound_declarators(compound_t *compound,
5850                 const declaration_specifiers_t *specifiers)
5851 {
5852         do {
5853                 entity_t *entity;
5854
5855                 if (token.type == ':') {
5856                         source_position_t source_position = *HERE;
5857                         next_token();
5858
5859                         type_t *base_type = specifiers->type;
5860                         expression_t *size = parse_constant_expression();
5861
5862                         type_t *type = make_bitfield_type(base_type, size,
5863                                         &source_position, NULL);
5864
5865                         attribute_t  *attributes = parse_attributes(NULL);
5866                         attribute_t **anchor     = &attributes;
5867                         while (*anchor != NULL)
5868                                 anchor = &(*anchor)->next;
5869                         *anchor = specifiers->attributes;
5870
5871                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER);
5872                         entity->base.namespc                       = NAMESPACE_NORMAL;
5873                         entity->base.source_position               = source_position;
5874                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5875                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5876                         entity->declaration.type                   = type;
5877                         entity->declaration.attributes             = attributes;
5878
5879                         if (attributes != NULL) {
5880                                 handle_entity_attributes(attributes, entity);
5881                         }
5882                         append_entity(&compound->members, entity);
5883                 } else {
5884                         entity = parse_declarator(specifiers,
5885                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5886                         if (entity->kind == ENTITY_TYPEDEF) {
5887                                 errorf(&entity->base.source_position,
5888                                                 "typedef not allowed as compound member");
5889                         } else {
5890                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5891
5892                                 /* make sure we don't define a symbol multiple times */
5893                                 symbol_t *symbol = entity->base.symbol;
5894                                 if (symbol != NULL) {
5895                                         entity_t *prev = find_compound_entry(compound, symbol);
5896                                         if (prev != NULL) {
5897                                                 errorf(&entity->base.source_position,
5898                                                                 "multiple declarations of symbol '%Y' (declared %P)",
5899                                                                 symbol, &prev->base.source_position);
5900                                         }
5901                                 }
5902
5903                                 if (token.type == ':') {
5904                                         source_position_t source_position = *HERE;
5905                                         next_token();
5906                                         expression_t *size = parse_constant_expression();
5907
5908                                         type_t *type          = entity->declaration.type;
5909                                         type_t *bitfield_type = make_bitfield_type(type, size,
5910                                                         &source_position, entity->base.symbol);
5911
5912                                         attribute_t *attributes = parse_attributes(NULL);
5913                                         entity->declaration.type = bitfield_type;
5914                                         handle_entity_attributes(attributes, entity);
5915                                 } else {
5916                                         type_t *orig_type = entity->declaration.type;
5917                                         type_t *type      = skip_typeref(orig_type);
5918                                         if (is_type_function(type)) {
5919                                                 errorf(&entity->base.source_position,
5920                                                        "compound member '%Y' must not have function type '%T'",
5921                                                                 entity->base.symbol, orig_type);
5922                                         } else if (is_type_incomplete(type)) {
5923                                                 /* §6.7.2.1:16 flexible array member */
5924                                                 if (!is_type_array(type)       ||
5925                                                                 token.type          != ';' ||
5926                                                                 look_ahead(1)->type != '}') {
5927                                                         errorf(&entity->base.source_position,
5928                                                                "compound member '%Y' has incomplete type '%T'",
5929                                                                         entity->base.symbol, orig_type);
5930                                                 }
5931                                         }
5932                                 }
5933
5934                                 append_entity(&compound->members, entity);
5935                         }
5936                 }
5937         } while (next_if(','));
5938         expect(';', end_error);
5939
5940 end_error:
5941         anonymous_entity = NULL;
5942 }
5943
5944 static void parse_compound_type_entries(compound_t *compound)
5945 {
5946         eat('{');
5947         add_anchor_token('}');
5948
5949         while (token.type != '}') {
5950                 if (token.type == T_EOF) {
5951                         errorf(HERE, "EOF while parsing struct");
5952                         break;
5953                 }
5954                 declaration_specifiers_t specifiers;
5955                 parse_declaration_specifiers(&specifiers);
5956                 parse_compound_declarators(compound, &specifiers);
5957         }
5958         rem_anchor_token('}');
5959         next_token();
5960
5961         /* §6.7.2.1:7 */
5962         compound->complete = true;
5963 }
5964
5965 static type_t *parse_typename(void)
5966 {
5967         declaration_specifiers_t specifiers;
5968         parse_declaration_specifiers(&specifiers);
5969         if (specifiers.storage_class != STORAGE_CLASS_NONE
5970                         || specifiers.thread_local) {
5971                 /* TODO: improve error message, user does probably not know what a
5972                  * storage class is...
5973                  */
5974                 errorf(HERE, "typename must not have a storage class");
5975         }
5976
5977         type_t *result = parse_abstract_declarator(specifiers.type);
5978
5979         return result;
5980 }
5981
5982
5983
5984
5985 typedef expression_t* (*parse_expression_function)(void);
5986 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5987
5988 typedef struct expression_parser_function_t expression_parser_function_t;
5989 struct expression_parser_function_t {
5990         parse_expression_function        parser;
5991         precedence_t                     infix_precedence;
5992         parse_expression_infix_function  infix_parser;
5993 };
5994
5995 expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5996
5997 /**
5998  * Prints an error message if an expression was expected but not read
5999  */
6000 static expression_t *expected_expression_error(void)
6001 {
6002         /* skip the error message if the error token was read */
6003         if (token.type != T_ERROR) {
6004                 errorf(HERE, "expected expression, got token %K", &token);
6005         }
6006         next_token();
6007
6008         return create_invalid_expression();
6009 }
6010
6011 static type_t *get_string_type(void)
6012 {
6013         return warning.write_strings ? type_const_char_ptr : type_char_ptr;
6014 }
6015
6016 static type_t *get_wide_string_type(void)
6017 {
6018         return warning.write_strings ? type_const_wchar_t_ptr : type_wchar_t_ptr;
6019 }
6020
6021 /**
6022  * Parse a string constant.
6023  */
6024 static expression_t *parse_string_literal(void)
6025 {
6026         source_position_t begin   = token.source_position;
6027         string_t          res     = token.literal;
6028         bool              is_wide = (token.type == T_WIDE_STRING_LITERAL);
6029
6030         next_token();
6031         while (token.type == T_STRING_LITERAL
6032                         || token.type == T_WIDE_STRING_LITERAL) {
6033                 warn_string_concat(&token.source_position);
6034                 res = concat_strings(&res, &token.literal);
6035                 next_token();
6036                 is_wide |= token.type == T_WIDE_STRING_LITERAL;
6037         }
6038
6039         expression_t *literal;
6040         if (is_wide) {
6041                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
6042                 literal->base.type = get_wide_string_type();
6043         } else {
6044                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
6045                 literal->base.type = get_string_type();
6046         }
6047         literal->base.source_position = begin;
6048         literal->literal.value        = res;
6049
6050         return literal;
6051 }
6052
6053 /**
6054  * Parse a boolean constant.
6055  */
6056 static expression_t *parse_boolean_literal(bool value)
6057 {
6058         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
6059         literal->base.source_position = token.source_position;
6060         literal->base.type            = type_bool;
6061         literal->literal.value.begin  = value ? "true" : "false";
6062         literal->literal.value.size   = value ? 4 : 5;
6063
6064         next_token();
6065         return literal;
6066 }
6067
6068 static void warn_traditional_suffix(void)
6069 {
6070         if (!warning.traditional)
6071                 return;
6072         warningf(&token.source_position, "traditional C rejects the '%Y' suffix",
6073                  token.symbol);
6074 }
6075
6076 static void check_integer_suffix(void)
6077 {
6078         symbol_t *suffix = token.symbol;
6079         if (suffix == NULL)
6080                 return;
6081
6082         bool not_traditional = false;
6083         const char *c = suffix->string;
6084         if (*c == 'l' || *c == 'L') {
6085                 ++c;
6086                 if (*c == *(c-1)) {
6087                         not_traditional = true;
6088                         ++c;
6089                         if (*c == 'u' || *c == 'U') {
6090                                 ++c;
6091                         }
6092                 } else if (*c == 'u' || *c == 'U') {
6093                         not_traditional = true;
6094                         ++c;
6095                 }
6096         } else if (*c == 'u' || *c == 'U') {
6097                 not_traditional = true;
6098                 ++c;
6099                 if (*c == 'l' || *c == 'L') {
6100                         ++c;
6101                         if (*c == *(c-1)) {
6102                                 ++c;
6103                         }
6104                 }
6105         }
6106         if (*c != '\0') {
6107                 errorf(&token.source_position,
6108                        "invalid suffix '%s' on integer constant", suffix->string);
6109         } else if (not_traditional) {
6110                 warn_traditional_suffix();
6111         }
6112 }
6113
6114 static type_t *check_floatingpoint_suffix(void)
6115 {
6116         symbol_t *suffix = token.symbol;
6117         type_t   *type   = type_double;
6118         if (suffix == NULL)
6119                 return type;
6120
6121         bool not_traditional = false;
6122         const char *c = suffix->string;
6123         if (*c == 'f' || *c == 'F') {
6124                 ++c;
6125                 type = type_float;
6126         } else if (*c == 'l' || *c == 'L') {
6127                 ++c;
6128                 type = type_long_double;
6129         }
6130         if (*c != '\0') {
6131                 errorf(&token.source_position,
6132                        "invalid suffix '%s' on floatingpoint constant", suffix->string);
6133         } else if (not_traditional) {
6134                 warn_traditional_suffix();
6135         }
6136
6137         return type;
6138 }
6139
6140 /**
6141  * Parse an integer constant.
6142  */
6143 static expression_t *parse_number_literal(void)
6144 {
6145         expression_kind_t  kind;
6146         type_t            *type;
6147
6148         switch (token.type) {
6149         case T_INTEGER:
6150                 kind = EXPR_LITERAL_INTEGER;
6151                 check_integer_suffix();
6152                 type = type_int;
6153                 break;
6154         case T_INTEGER_OCTAL:
6155                 kind = EXPR_LITERAL_INTEGER_OCTAL;
6156                 check_integer_suffix();
6157                 type = type_int;
6158                 break;
6159         case T_INTEGER_HEXADECIMAL:
6160                 kind = EXPR_LITERAL_INTEGER_HEXADECIMAL;
6161                 check_integer_suffix();
6162                 type = type_int;
6163                 break;
6164         case T_FLOATINGPOINT:
6165                 kind = EXPR_LITERAL_FLOATINGPOINT;
6166                 type = check_floatingpoint_suffix();
6167                 break;
6168         case T_FLOATINGPOINT_HEXADECIMAL:
6169                 kind = EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL;
6170                 type = check_floatingpoint_suffix();
6171                 break;
6172         default:
6173                 panic("unexpected token type in parse_number_literal");
6174         }
6175
6176         expression_t *literal = allocate_expression_zero(kind);
6177         literal->base.source_position = token.source_position;
6178         literal->base.type            = type;
6179         literal->literal.value        = token.literal;
6180         literal->literal.suffix       = token.symbol;
6181         next_token();
6182
6183         /* integer type depends on the size of the number and the size
6184          * representable by the types. The backend/codegeneration has to determine
6185          * that
6186          */
6187         determine_literal_type(&literal->literal);
6188         return literal;
6189 }
6190
6191 /**
6192  * Parse a character constant.
6193  */
6194 static expression_t *parse_character_constant(void)
6195 {
6196         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
6197         literal->base.source_position = token.source_position;
6198         literal->base.type            = c_mode & _CXX ? type_char : type_int;
6199         literal->literal.value        = token.literal;
6200
6201         size_t len = literal->literal.value.size;
6202         if (len > 1) {
6203                 if (!GNU_MODE && !(c_mode & _C99)) {
6204                         errorf(HERE, "more than 1 character in character constant");
6205                 } else if (warning.multichar) {
6206                         literal->base.type = type_int;
6207                         warningf(HERE, "multi-character character constant");
6208                 }
6209         }
6210
6211         next_token();
6212         return literal;
6213 }
6214
6215 /**
6216  * Parse a wide character constant.
6217  */
6218 static expression_t *parse_wide_character_constant(void)
6219 {
6220         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
6221         literal->base.source_position = token.source_position;
6222         literal->base.type            = type_int;
6223         literal->literal.value        = token.literal;
6224
6225         size_t len = wstrlen(&literal->literal.value);
6226         if (len > 1) {
6227                 warningf(HERE, "multi-character character constant");
6228         }
6229
6230         next_token();
6231         return literal;
6232 }
6233
6234 static entity_t *create_implicit_function(symbol_t *symbol,
6235                 const source_position_t *source_position)
6236 {
6237         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
6238         ntype->function.return_type            = type_int;
6239         ntype->function.unspecified_parameters = true;
6240         ntype->function.linkage                = LINKAGE_C;
6241         type_t *type                           = identify_new_type(ntype);
6242
6243         entity_t *entity = allocate_entity_zero(ENTITY_FUNCTION);
6244         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
6245         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
6246         entity->declaration.type                   = type;
6247         entity->declaration.implicit               = true;
6248         entity->base.namespc                       = NAMESPACE_NORMAL;
6249         entity->base.symbol                        = symbol;
6250         entity->base.source_position               = *source_position;
6251
6252         if (current_scope != NULL) {
6253                 bool strict_prototypes_old = warning.strict_prototypes;
6254                 warning.strict_prototypes  = false;
6255                 record_entity(entity, false);
6256                 warning.strict_prototypes = strict_prototypes_old;
6257         }
6258
6259         return entity;
6260 }
6261
6262 /**
6263  * Performs automatic type cast as described in §6.3.2.1.
6264  *
6265  * @param orig_type  the original type
6266  */
6267 static type_t *automatic_type_conversion(type_t *orig_type)
6268 {
6269         type_t *type = skip_typeref(orig_type);
6270         if (is_type_array(type)) {
6271                 array_type_t *array_type   = &type->array;
6272                 type_t       *element_type = array_type->element_type;
6273                 unsigned      qualifiers   = array_type->base.qualifiers;
6274
6275                 return make_pointer_type(element_type, qualifiers);
6276         }
6277
6278         if (is_type_function(type)) {
6279                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
6280         }
6281
6282         return orig_type;
6283 }
6284
6285 /**
6286  * reverts the automatic casts of array to pointer types and function
6287  * to function-pointer types as defined §6.3.2.1
6288  */
6289 type_t *revert_automatic_type_conversion(const expression_t *expression)
6290 {
6291         switch (expression->kind) {
6292         case EXPR_REFERENCE: {
6293                 entity_t *entity = expression->reference.entity;
6294                 if (is_declaration(entity)) {
6295                         return entity->declaration.type;
6296                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
6297                         return entity->enum_value.enum_type;
6298                 } else {
6299                         panic("no declaration or enum in reference");
6300                 }
6301         }
6302
6303         case EXPR_SELECT: {
6304                 entity_t *entity = expression->select.compound_entry;
6305                 assert(is_declaration(entity));
6306                 type_t   *type   = entity->declaration.type;
6307                 return get_qualified_type(type,
6308                                 expression->base.type->base.qualifiers);
6309         }
6310
6311         case EXPR_UNARY_DEREFERENCE: {
6312                 const expression_t *const value = expression->unary.value;
6313                 type_t             *const type  = skip_typeref(value->base.type);
6314                 if (!is_type_pointer(type))
6315                         return type_error_type;
6316                 return type->pointer.points_to;
6317         }
6318
6319         case EXPR_ARRAY_ACCESS: {
6320                 const expression_t *array_ref = expression->array_access.array_ref;
6321                 type_t             *type_left = skip_typeref(array_ref->base.type);
6322                 if (!is_type_pointer(type_left))
6323                         return type_error_type;
6324                 return type_left->pointer.points_to;
6325         }
6326
6327         case EXPR_STRING_LITERAL: {
6328                 size_t size = expression->string_literal.value.size;
6329                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
6330         }
6331
6332         case EXPR_WIDE_STRING_LITERAL: {
6333                 size_t size = wstrlen(&expression->string_literal.value);
6334                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
6335         }
6336
6337         case EXPR_COMPOUND_LITERAL:
6338                 return expression->compound_literal.type;
6339
6340         default:
6341                 break;
6342         }
6343         return expression->base.type;
6344 }
6345
6346 /**
6347  * Find an entity matching a symbol in a scope.
6348  * Uses current scope if scope is NULL
6349  */
6350 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6351                                namespace_tag_t namespc)
6352 {
6353         if (scope == NULL) {
6354                 return get_entity(symbol, namespc);
6355         }
6356
6357         /* we should optimize here, if scope grows above a certain size we should
6358            construct a hashmap here... */
6359         entity_t *entity = scope->entities;
6360         for ( ; entity != NULL; entity = entity->base.next) {
6361                 if (entity->base.symbol == symbol && entity->base.namespc == namespc)
6362                         break;
6363         }
6364
6365         return entity;
6366 }
6367
6368 static entity_t *parse_qualified_identifier(void)
6369 {
6370         /* namespace containing the symbol */
6371         symbol_t          *symbol;
6372         source_position_t  pos;
6373         const scope_t     *lookup_scope = NULL;
6374
6375         if (next_if(T_COLONCOLON))
6376                 lookup_scope = &unit->scope;
6377
6378         entity_t *entity;
6379         while (true) {
6380                 if (token.type != T_IDENTIFIER) {
6381                         parse_error_expected("while parsing identifier", T_IDENTIFIER, NULL);
6382                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6383                 }
6384                 symbol = token.symbol;
6385                 pos    = *HERE;
6386                 next_token();
6387
6388                 /* lookup entity */
6389                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6390
6391                 if (!next_if(T_COLONCOLON))
6392                         break;
6393
6394                 switch (entity->kind) {
6395                 case ENTITY_NAMESPACE:
6396                         lookup_scope = &entity->namespacee.members;
6397                         break;
6398                 case ENTITY_STRUCT:
6399                 case ENTITY_UNION:
6400                 case ENTITY_CLASS:
6401                         lookup_scope = &entity->compound.members;
6402                         break;
6403                 default:
6404                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6405                                symbol, get_entity_kind_name(entity->kind));
6406                         goto end_error;
6407                 }
6408         }
6409
6410         if (entity == NULL) {
6411                 if (!strict_mode && token.type == '(') {
6412                         /* an implicitly declared function */
6413                         if (warning.error_implicit_function_declaration) {
6414                                 errorf(&pos, "implicit declaration of function '%Y'", symbol);
6415                         } else if (warning.implicit_function_declaration) {
6416                                 warningf(&pos, "implicit declaration of function '%Y'", symbol);
6417                         }
6418
6419                         entity = create_implicit_function(symbol, &pos);
6420                 } else {
6421                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6422                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6423                 }
6424         }
6425
6426         return entity;
6427
6428 end_error:
6429         /* skip further qualifications */
6430         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6431
6432         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6433 }
6434
6435 static expression_t *parse_reference(void)
6436 {
6437         source_position_t const pos    = token.source_position;
6438         entity_t         *const entity = parse_qualified_identifier();
6439
6440         type_t *orig_type;
6441         if (is_declaration(entity)) {
6442                 orig_type = entity->declaration.type;
6443         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6444                 orig_type = entity->enum_value.enum_type;
6445         } else {
6446                 panic("expected declaration or enum value in reference");
6447         }
6448
6449         /* we always do the auto-type conversions; the & and sizeof parser contains
6450          * code to revert this! */
6451         type_t *type = automatic_type_conversion(orig_type);
6452
6453         expression_kind_t kind = EXPR_REFERENCE;
6454         if (entity->kind == ENTITY_ENUM_VALUE)
6455                 kind = EXPR_REFERENCE_ENUM_VALUE;
6456
6457         expression_t *expression         = allocate_expression_zero(kind);
6458         expression->base.source_position = pos;
6459         expression->base.type            = type;
6460         expression->reference.entity     = entity;
6461
6462         /* this declaration is used */
6463         if (is_declaration(entity)) {
6464                 entity->declaration.used = true;
6465         }
6466
6467         if (entity->base.parent_scope != file_scope
6468                 && (current_function != NULL
6469                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6470                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6471                 if (entity->kind == ENTITY_VARIABLE) {
6472                         /* access of a variable from an outer function */
6473                         entity->variable.address_taken = true;
6474                 } else if (entity->kind == ENTITY_PARAMETER) {
6475                         entity->parameter.address_taken = true;
6476                 }
6477                 current_function->need_closure = true;
6478         }
6479
6480         check_deprecated(HERE, entity);
6481
6482         if (warning.init_self && entity == current_init_decl && !in_type_prop
6483             && entity->kind == ENTITY_VARIABLE) {
6484                 current_init_decl = NULL;
6485                 warningf(&pos, "variable '%#T' is initialized by itself",
6486                          entity->declaration.type, entity->base.symbol);
6487         }
6488
6489         return expression;
6490 }
6491
6492 static bool semantic_cast(expression_t *cast)
6493 {
6494         expression_t            *expression      = cast->unary.value;
6495         type_t                  *orig_dest_type  = cast->base.type;
6496         type_t                  *orig_type_right = expression->base.type;
6497         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6498         type_t            const *src_type        = skip_typeref(orig_type_right);
6499         source_position_t const *pos             = &cast->base.source_position;
6500
6501         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6502         if (dst_type == type_void)
6503                 return true;
6504
6505         /* only integer and pointer can be casted to pointer */
6506         if (is_type_pointer(dst_type)  &&
6507             !is_type_pointer(src_type) &&
6508             !is_type_integer(src_type) &&
6509             is_type_valid(src_type)) {
6510                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6511                 return false;
6512         }
6513
6514         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6515                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6516                 return false;
6517         }
6518
6519         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6520                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6521                 return false;
6522         }
6523
6524         if (warning.cast_qual &&
6525             is_type_pointer(src_type) &&
6526             is_type_pointer(dst_type)) {
6527                 type_t *src = skip_typeref(src_type->pointer.points_to);
6528                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6529                 unsigned missing_qualifiers =
6530                         src->base.qualifiers & ~dst->base.qualifiers;
6531                 if (missing_qualifiers != 0) {
6532                         warningf(pos,
6533                                  "cast discards qualifiers '%Q' in pointer target type of '%T'",
6534                                  missing_qualifiers, orig_type_right);
6535                 }
6536         }
6537         return true;
6538 }
6539
6540 static expression_t *parse_compound_literal(type_t *type)
6541 {
6542         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6543
6544         parse_initializer_env_t env;
6545         env.type             = type;
6546         env.entity           = NULL;
6547         env.must_be_constant = false;
6548         initializer_t *initializer = parse_initializer(&env);
6549         type = env.type;
6550
6551         expression->compound_literal.initializer = initializer;
6552         expression->compound_literal.type        = type;
6553         expression->base.type                    = automatic_type_conversion(type);
6554
6555         return expression;
6556 }
6557
6558 /**
6559  * Parse a cast expression.
6560  */
6561 static expression_t *parse_cast(void)
6562 {
6563         source_position_t source_position = token.source_position;
6564
6565         eat('(');
6566         add_anchor_token(')');
6567
6568         type_t *type = parse_typename();
6569
6570         rem_anchor_token(')');
6571         expect(')', end_error);
6572
6573         if (token.type == '{') {
6574                 return parse_compound_literal(type);
6575         }
6576
6577         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6578         cast->base.source_position = source_position;
6579
6580         expression_t *value = parse_subexpression(PREC_CAST);
6581         cast->base.type   = type;
6582         cast->unary.value = value;
6583
6584         if (! semantic_cast(cast)) {
6585                 /* TODO: record the error in the AST. else it is impossible to detect it */
6586         }
6587
6588         return cast;
6589 end_error:
6590         return create_invalid_expression();
6591 }
6592
6593 /**
6594  * Parse a statement expression.
6595  */
6596 static expression_t *parse_statement_expression(void)
6597 {
6598         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6599
6600         eat('(');
6601         add_anchor_token(')');
6602
6603         statement_t *statement          = parse_compound_statement(true);
6604         statement->compound.stmt_expr   = true;
6605         expression->statement.statement = statement;
6606
6607         /* find last statement and use its type */
6608         type_t *type = type_void;
6609         const statement_t *stmt = statement->compound.statements;
6610         if (stmt != NULL) {
6611                 while (stmt->base.next != NULL)
6612                         stmt = stmt->base.next;
6613
6614                 if (stmt->kind == STATEMENT_EXPRESSION) {
6615                         type = stmt->expression.expression->base.type;
6616                 }
6617         } else if (warning.other) {
6618                 warningf(&expression->base.source_position, "empty statement expression ({})");
6619         }
6620         expression->base.type = type;
6621
6622         rem_anchor_token(')');
6623         expect(')', end_error);
6624
6625 end_error:
6626         return expression;
6627 }
6628
6629 /**
6630  * Parse a parenthesized expression.
6631  */
6632 static expression_t *parse_parenthesized_expression(void)
6633 {
6634         token_t const* const la1 = look_ahead(1);
6635         switch (la1->type) {
6636         case '{':
6637                 /* gcc extension: a statement expression */
6638                 return parse_statement_expression();
6639
6640         case T_IDENTIFIER:
6641                 if (is_typedef_symbol(la1->symbol)) {
6642         TYPE_QUALIFIERS
6643         TYPE_SPECIFIERS
6644                         return parse_cast();
6645                 }
6646         }
6647
6648         eat('(');
6649         add_anchor_token(')');
6650         expression_t *result = parse_expression();
6651         result->base.parenthesized = true;
6652         rem_anchor_token(')');
6653         expect(')', end_error);
6654
6655 end_error:
6656         return result;
6657 }
6658
6659 static expression_t *parse_function_keyword(void)
6660 {
6661         /* TODO */
6662
6663         if (current_function == NULL) {
6664                 errorf(HERE, "'__func__' used outside of a function");
6665         }
6666
6667         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6668         expression->base.type     = type_char_ptr;
6669         expression->funcname.kind = FUNCNAME_FUNCTION;
6670
6671         next_token();
6672
6673         return expression;
6674 }
6675
6676 static expression_t *parse_pretty_function_keyword(void)
6677 {
6678         if (current_function == NULL) {
6679                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6680         }
6681
6682         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6683         expression->base.type     = type_char_ptr;
6684         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6685
6686         eat(T___PRETTY_FUNCTION__);
6687
6688         return expression;
6689 }
6690
6691 static expression_t *parse_funcsig_keyword(void)
6692 {
6693         if (current_function == NULL) {
6694                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6695         }
6696
6697         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6698         expression->base.type     = type_char_ptr;
6699         expression->funcname.kind = FUNCNAME_FUNCSIG;
6700
6701         eat(T___FUNCSIG__);
6702
6703         return expression;
6704 }
6705
6706 static expression_t *parse_funcdname_keyword(void)
6707 {
6708         if (current_function == NULL) {
6709                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6710         }
6711
6712         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6713         expression->base.type     = type_char_ptr;
6714         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6715
6716         eat(T___FUNCDNAME__);
6717
6718         return expression;
6719 }
6720
6721 static designator_t *parse_designator(void)
6722 {
6723         designator_t *result    = allocate_ast_zero(sizeof(result[0]));
6724         result->source_position = *HERE;
6725
6726         if (token.type != T_IDENTIFIER) {
6727                 parse_error_expected("while parsing member designator",
6728                                      T_IDENTIFIER, NULL);
6729                 return NULL;
6730         }
6731         result->symbol = token.symbol;
6732         next_token();
6733
6734         designator_t *last_designator = result;
6735         while (true) {
6736                 if (next_if('.')) {
6737                         if (token.type != T_IDENTIFIER) {
6738                                 parse_error_expected("while parsing member designator",
6739                                                      T_IDENTIFIER, NULL);
6740                                 return NULL;
6741                         }
6742                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6743                         designator->source_position = *HERE;
6744                         designator->symbol          = token.symbol;
6745                         next_token();
6746
6747                         last_designator->next = designator;
6748                         last_designator       = designator;
6749                         continue;
6750                 }
6751                 if (next_if('[')) {
6752                         add_anchor_token(']');
6753                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6754                         designator->source_position = *HERE;
6755                         designator->array_index     = parse_expression();
6756                         rem_anchor_token(']');
6757                         expect(']', end_error);
6758                         if (designator->array_index == NULL) {
6759                                 return NULL;
6760                         }
6761
6762                         last_designator->next = designator;
6763                         last_designator       = designator;
6764                         continue;
6765                 }
6766                 break;
6767         }
6768
6769         return result;
6770 end_error:
6771         return NULL;
6772 }
6773
6774 /**
6775  * Parse the __builtin_offsetof() expression.
6776  */
6777 static expression_t *parse_offsetof(void)
6778 {
6779         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6780         expression->base.type    = type_size_t;
6781
6782         eat(T___builtin_offsetof);
6783
6784         expect('(', end_error);
6785         add_anchor_token(',');
6786         type_t *type = parse_typename();
6787         rem_anchor_token(',');
6788         expect(',', end_error);
6789         add_anchor_token(')');
6790         designator_t *designator = parse_designator();
6791         rem_anchor_token(')');
6792         expect(')', end_error);
6793
6794         expression->offsetofe.type       = type;
6795         expression->offsetofe.designator = designator;
6796
6797         type_path_t path;
6798         memset(&path, 0, sizeof(path));
6799         path.top_type = type;
6800         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6801
6802         descend_into_subtype(&path);
6803
6804         if (!walk_designator(&path, designator, true)) {
6805                 return create_invalid_expression();
6806         }
6807
6808         DEL_ARR_F(path.path);
6809
6810         return expression;
6811 end_error:
6812         return create_invalid_expression();
6813 }
6814
6815 /**
6816  * Parses a _builtin_va_start() expression.
6817  */
6818 static expression_t *parse_va_start(void)
6819 {
6820         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6821
6822         eat(T___builtin_va_start);
6823
6824         expect('(', end_error);
6825         add_anchor_token(',');
6826         expression->va_starte.ap = parse_assignment_expression();
6827         rem_anchor_token(',');
6828         expect(',', end_error);
6829         expression_t *const expr = parse_assignment_expression();
6830         if (expr->kind == EXPR_REFERENCE) {
6831                 entity_t *const entity = expr->reference.entity;
6832                 if (!current_function->base.type->function.variadic) {
6833                         errorf(&expr->base.source_position,
6834                                         "'va_start' used in non-variadic function");
6835                 } else if (entity->base.parent_scope != &current_function->parameters ||
6836                                 entity->base.next != NULL ||
6837                                 entity->kind != ENTITY_PARAMETER) {
6838                         errorf(&expr->base.source_position,
6839                                "second argument of 'va_start' must be last parameter of the current function");
6840                 } else {
6841                         expression->va_starte.parameter = &entity->variable;
6842                 }
6843                 expect(')', end_error);
6844                 return expression;
6845         }
6846         expect(')', end_error);
6847 end_error:
6848         return create_invalid_expression();
6849 }
6850
6851 /**
6852  * Parses a __builtin_va_arg() expression.
6853  */
6854 static expression_t *parse_va_arg(void)
6855 {
6856         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6857
6858         eat(T___builtin_va_arg);
6859
6860         expect('(', end_error);
6861         call_argument_t ap;
6862         ap.expression = parse_assignment_expression();
6863         expression->va_arge.ap = ap.expression;
6864         check_call_argument(type_valist, &ap, 1);
6865
6866         expect(',', end_error);
6867         expression->base.type = parse_typename();
6868         expect(')', end_error);
6869
6870         return expression;
6871 end_error:
6872         return create_invalid_expression();
6873 }
6874
6875 /**
6876  * Parses a __builtin_va_copy() expression.
6877  */
6878 static expression_t *parse_va_copy(void)
6879 {
6880         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6881
6882         eat(T___builtin_va_copy);
6883
6884         expect('(', end_error);
6885         expression_t *dst = parse_assignment_expression();
6886         assign_error_t error = semantic_assign(type_valist, dst);
6887         report_assign_error(error, type_valist, dst, "call argument 1",
6888                             &dst->base.source_position);
6889         expression->va_copye.dst = dst;
6890
6891         expect(',', end_error);
6892
6893         call_argument_t src;
6894         src.expression = parse_assignment_expression();
6895         check_call_argument(type_valist, &src, 2);
6896         expression->va_copye.src = src.expression;
6897         expect(')', end_error);
6898
6899         return expression;
6900 end_error:
6901         return create_invalid_expression();
6902 }
6903
6904 /**
6905  * Parses a __builtin_constant_p() expression.
6906  */
6907 static expression_t *parse_builtin_constant(void)
6908 {
6909         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6910
6911         eat(T___builtin_constant_p);
6912
6913         expect('(', end_error);
6914         add_anchor_token(')');
6915         expression->builtin_constant.value = parse_assignment_expression();
6916         rem_anchor_token(')');
6917         expect(')', end_error);
6918         expression->base.type = type_int;
6919
6920         return expression;
6921 end_error:
6922         return create_invalid_expression();
6923 }
6924
6925 /**
6926  * Parses a __builtin_types_compatible_p() expression.
6927  */
6928 static expression_t *parse_builtin_types_compatible(void)
6929 {
6930         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6931
6932         eat(T___builtin_types_compatible_p);
6933
6934         expect('(', end_error);
6935         add_anchor_token(')');
6936         add_anchor_token(',');
6937         expression->builtin_types_compatible.left = parse_typename();
6938         rem_anchor_token(',');
6939         expect(',', end_error);
6940         expression->builtin_types_compatible.right = parse_typename();
6941         rem_anchor_token(')');
6942         expect(')', end_error);
6943         expression->base.type = type_int;
6944
6945         return expression;
6946 end_error:
6947         return create_invalid_expression();
6948 }
6949
6950 /**
6951  * Parses a __builtin_is_*() compare expression.
6952  */
6953 static expression_t *parse_compare_builtin(void)
6954 {
6955         expression_t *expression;
6956
6957         switch (token.type) {
6958         case T___builtin_isgreater:
6959                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6960                 break;
6961         case T___builtin_isgreaterequal:
6962                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6963                 break;
6964         case T___builtin_isless:
6965                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6966                 break;
6967         case T___builtin_islessequal:
6968                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6969                 break;
6970         case T___builtin_islessgreater:
6971                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6972                 break;
6973         case T___builtin_isunordered:
6974                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6975                 break;
6976         default:
6977                 internal_errorf(HERE, "invalid compare builtin found");
6978         }
6979         expression->base.source_position = *HERE;
6980         next_token();
6981
6982         expect('(', end_error);
6983         expression->binary.left = parse_assignment_expression();
6984         expect(',', end_error);
6985         expression->binary.right = parse_assignment_expression();
6986         expect(')', end_error);
6987
6988         type_t *const orig_type_left  = expression->binary.left->base.type;
6989         type_t *const orig_type_right = expression->binary.right->base.type;
6990
6991         type_t *const type_left  = skip_typeref(orig_type_left);
6992         type_t *const type_right = skip_typeref(orig_type_right);
6993         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6994                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6995                         type_error_incompatible("invalid operands in comparison",
6996                                 &expression->base.source_position, orig_type_left, orig_type_right);
6997                 }
6998         } else {
6999                 semantic_comparison(&expression->binary);
7000         }
7001
7002         return expression;
7003 end_error:
7004         return create_invalid_expression();
7005 }
7006
7007 /**
7008  * Parses a MS assume() expression.
7009  */
7010 static expression_t *parse_assume(void)
7011 {
7012         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
7013
7014         eat(T__assume);
7015
7016         expect('(', end_error);
7017         add_anchor_token(')');
7018         expression->unary.value = parse_assignment_expression();
7019         rem_anchor_token(')');
7020         expect(')', end_error);
7021
7022         expression->base.type = type_void;
7023         return expression;
7024 end_error:
7025         return create_invalid_expression();
7026 }
7027
7028 /**
7029  * Return the declaration for a given label symbol or create a new one.
7030  *
7031  * @param symbol  the symbol of the label
7032  */
7033 static label_t *get_label(symbol_t *symbol)
7034 {
7035         entity_t *label;
7036         assert(current_function != NULL);
7037
7038         label = get_entity(symbol, NAMESPACE_LABEL);
7039         /* if we found a local label, we already created the declaration */
7040         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
7041                 if (label->base.parent_scope != current_scope) {
7042                         assert(label->base.parent_scope->depth < current_scope->depth);
7043                         current_function->goto_to_outer = true;
7044                 }
7045                 return &label->label;
7046         }
7047
7048         label = get_entity(symbol, NAMESPACE_LABEL);
7049         /* if we found a label in the same function, then we already created the
7050          * declaration */
7051         if (label != NULL
7052                         && label->base.parent_scope == &current_function->parameters) {
7053                 return &label->label;
7054         }
7055
7056         /* otherwise we need to create a new one */
7057         label               = allocate_entity_zero(ENTITY_LABEL);
7058         label->base.namespc = NAMESPACE_LABEL;
7059         label->base.symbol  = symbol;
7060
7061         label_push(label);
7062
7063         return &label->label;
7064 }
7065
7066 /**
7067  * Parses a GNU && label address expression.
7068  */
7069 static expression_t *parse_label_address(void)
7070 {
7071         source_position_t source_position = token.source_position;
7072         eat(T_ANDAND);
7073         if (token.type != T_IDENTIFIER) {
7074                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
7075                 goto end_error;
7076         }
7077         symbol_t *symbol = token.symbol;
7078         next_token();
7079
7080         label_t *label       = get_label(symbol);
7081         label->used          = true;
7082         label->address_taken = true;
7083
7084         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
7085         expression->base.source_position = source_position;
7086
7087         /* label address is threaten as a void pointer */
7088         expression->base.type           = type_void_ptr;
7089         expression->label_address.label = label;
7090         return expression;
7091 end_error:
7092         return create_invalid_expression();
7093 }
7094
7095 /**
7096  * Parse a microsoft __noop expression.
7097  */
7098 static expression_t *parse_noop_expression(void)
7099 {
7100         /* the result is a (int)0 */
7101         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
7102         literal->base.type            = type_int;
7103         literal->base.source_position = token.source_position;
7104         literal->literal.value.begin  = "__noop";
7105         literal->literal.value.size   = 6;
7106
7107         eat(T___noop);
7108
7109         if (token.type == '(') {
7110                 /* parse arguments */
7111                 eat('(');
7112                 add_anchor_token(')');
7113                 add_anchor_token(',');
7114
7115                 if (token.type != ')') do {
7116                         (void)parse_assignment_expression();
7117                 } while (next_if(','));
7118         }
7119         rem_anchor_token(',');
7120         rem_anchor_token(')');
7121         expect(')', end_error);
7122
7123 end_error:
7124         return literal;
7125 }
7126
7127 /**
7128  * Parses a primary expression.
7129  */
7130 static expression_t *parse_primary_expression(void)
7131 {
7132         switch (token.type) {
7133         case T_false:                        return parse_boolean_literal(false);
7134         case T_true:                         return parse_boolean_literal(true);
7135         case T_INTEGER:
7136         case T_INTEGER_OCTAL:
7137         case T_INTEGER_HEXADECIMAL:
7138         case T_FLOATINGPOINT:
7139         case T_FLOATINGPOINT_HEXADECIMAL:    return parse_number_literal();
7140         case T_CHARACTER_CONSTANT:           return parse_character_constant();
7141         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
7142         case T_STRING_LITERAL:
7143         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
7144         case T___FUNCTION__:
7145         case T___func__:                     return parse_function_keyword();
7146         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
7147         case T___FUNCSIG__:                  return parse_funcsig_keyword();
7148         case T___FUNCDNAME__:                return parse_funcdname_keyword();
7149         case T___builtin_offsetof:           return parse_offsetof();
7150         case T___builtin_va_start:           return parse_va_start();
7151         case T___builtin_va_arg:             return parse_va_arg();
7152         case T___builtin_va_copy:            return parse_va_copy();
7153         case T___builtin_isgreater:
7154         case T___builtin_isgreaterequal:
7155         case T___builtin_isless:
7156         case T___builtin_islessequal:
7157         case T___builtin_islessgreater:
7158         case T___builtin_isunordered:        return parse_compare_builtin();
7159         case T___builtin_constant_p:         return parse_builtin_constant();
7160         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
7161         case T__assume:                      return parse_assume();
7162         case T_ANDAND:
7163                 if (GNU_MODE)
7164                         return parse_label_address();
7165                 break;
7166
7167         case '(':                            return parse_parenthesized_expression();
7168         case T___noop:                       return parse_noop_expression();
7169
7170         /* Gracefully handle type names while parsing expressions. */
7171         case T_COLONCOLON:
7172                 return parse_reference();
7173         case T_IDENTIFIER:
7174                 if (!is_typedef_symbol(token.symbol)) {
7175                         return parse_reference();
7176                 }
7177                 /* FALLTHROUGH */
7178         TYPENAME_START {
7179                 source_position_t  const pos  = *HERE;
7180                 type_t const      *const type = parse_typename();
7181                 errorf(&pos, "encountered type '%T' while parsing expression", type);
7182                 return create_invalid_expression();
7183         }
7184         }
7185
7186         errorf(HERE, "unexpected token %K, expected an expression", &token);
7187         eat_until_anchor();
7188         return create_invalid_expression();
7189 }
7190
7191 static expression_t *parse_array_expression(expression_t *left)
7192 {
7193         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
7194         array_access_expression_t *const arr  = &expr->array_access;
7195
7196         eat('[');
7197         add_anchor_token(']');
7198
7199         expression_t *const inside = parse_expression();
7200
7201         type_t *const orig_type_left   = left->base.type;
7202         type_t *const orig_type_inside = inside->base.type;
7203
7204         type_t *const type_left   = skip_typeref(orig_type_left);
7205         type_t *const type_inside = skip_typeref(orig_type_inside);
7206
7207         expression_t *ref;
7208         expression_t *idx;
7209         type_t       *idx_type;
7210         type_t       *res_type;
7211         if (is_type_pointer(type_left)) {
7212                 ref      = left;
7213                 idx      = inside;
7214                 idx_type = type_inside;
7215                 res_type = type_left->pointer.points_to;
7216                 goto check_idx;
7217         } else if (is_type_pointer(type_inside)) {
7218                 arr->flipped = true;
7219                 ref      = inside;
7220                 idx      = left;
7221                 idx_type = type_left;
7222                 res_type = type_inside->pointer.points_to;
7223 check_idx:
7224                 res_type = automatic_type_conversion(res_type);
7225                 if (!is_type_integer(idx_type)) {
7226                         errorf(&idx->base.source_position, "array subscript must have integer type");
7227                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR) && warning.char_subscripts) {
7228                         warningf(&idx->base.source_position, "array subscript has char type");
7229                 }
7230         } else {
7231                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
7232                         errorf(HERE,
7233                                 "array access on object with non-pointer types '%T', '%T'",
7234                                 orig_type_left, orig_type_inside);
7235                 }
7236                 res_type = type_error_type;
7237                 ref      = left;
7238                 idx      = inside;
7239         }
7240
7241         arr->array_ref = ref;
7242         arr->index     = idx;
7243         arr->base.type = res_type;
7244
7245         rem_anchor_token(']');
7246         expect(']', end_error);
7247 end_error:
7248         return expr;
7249 }
7250
7251 static expression_t *parse_typeprop(expression_kind_t const kind)
7252 {
7253         expression_t  *tp_expression = allocate_expression_zero(kind);
7254         tp_expression->base.type     = type_size_t;
7255
7256         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
7257
7258         /* we only refer to a type property, mark this case */
7259         bool old     = in_type_prop;
7260         in_type_prop = true;
7261
7262         type_t       *orig_type;
7263         expression_t *expression;
7264         if (token.type == '(' && is_declaration_specifier(look_ahead(1), true)) {
7265                 next_token();
7266                 add_anchor_token(')');
7267                 orig_type = parse_typename();
7268                 rem_anchor_token(')');
7269                 expect(')', end_error);
7270
7271                 if (token.type == '{') {
7272                         /* It was not sizeof(type) after all.  It is sizeof of an expression
7273                          * starting with a compound literal */
7274                         expression = parse_compound_literal(orig_type);
7275                         goto typeprop_expression;
7276                 }
7277         } else {
7278                 expression = parse_subexpression(PREC_UNARY);
7279
7280 typeprop_expression:
7281                 tp_expression->typeprop.tp_expression = expression;
7282
7283                 orig_type = revert_automatic_type_conversion(expression);
7284                 expression->base.type = orig_type;
7285         }
7286
7287         tp_expression->typeprop.type   = orig_type;
7288         type_t const* const type       = skip_typeref(orig_type);
7289         char   const*       wrong_type = NULL;
7290         if (is_type_incomplete(type)) {
7291                 if (!is_type_atomic(type, ATOMIC_TYPE_VOID) || !GNU_MODE)
7292                         wrong_type = "incomplete";
7293         } else if (type->kind == TYPE_FUNCTION) {
7294                 if (GNU_MODE) {
7295                         /* function types are allowed (and return 1) */
7296                         if (warning.other) {
7297                                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7298                                 warningf(&tp_expression->base.source_position,
7299                                          "%s expression with function argument returns invalid result", what);
7300                         }
7301                 } else {
7302                         wrong_type = "function";
7303                 }
7304         } else {
7305                 if (is_type_incomplete(type))
7306                         wrong_type = "incomplete";
7307         }
7308         if (type->kind == TYPE_BITFIELD)
7309                 wrong_type = "bitfield";
7310
7311         if (wrong_type != NULL) {
7312                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
7313                 errorf(&tp_expression->base.source_position,
7314                                 "operand of %s expression must not be of %s type '%T'",
7315                                 what, wrong_type, orig_type);
7316         }
7317
7318 end_error:
7319         in_type_prop = old;
7320         return tp_expression;
7321 }
7322
7323 static expression_t *parse_sizeof(void)
7324 {
7325         return parse_typeprop(EXPR_SIZEOF);
7326 }
7327
7328 static expression_t *parse_alignof(void)
7329 {
7330         return parse_typeprop(EXPR_ALIGNOF);
7331 }
7332
7333 static expression_t *parse_select_expression(expression_t *addr)
7334 {
7335         assert(token.type == '.' || token.type == T_MINUSGREATER);
7336         bool select_left_arrow = (token.type == T_MINUSGREATER);
7337         source_position_t const pos = *HERE;
7338         next_token();
7339
7340         if (token.type != T_IDENTIFIER) {
7341                 parse_error_expected("while parsing select", T_IDENTIFIER, NULL);
7342                 return create_invalid_expression();
7343         }
7344         symbol_t *symbol = token.symbol;
7345         next_token();
7346
7347         type_t *const orig_type = addr->base.type;
7348         type_t *const type      = skip_typeref(orig_type);
7349
7350         type_t *type_left;
7351         bool    saw_error = false;
7352         if (is_type_pointer(type)) {
7353                 if (!select_left_arrow) {
7354                         errorf(&pos,
7355                                "request for member '%Y' in something not a struct or union, but '%T'",
7356                                symbol, orig_type);
7357                         saw_error = true;
7358                 }
7359                 type_left = skip_typeref(type->pointer.points_to);
7360         } else {
7361                 if (select_left_arrow && is_type_valid(type)) {
7362                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
7363                         saw_error = true;
7364                 }
7365                 type_left = type;
7366         }
7367
7368         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
7369             type_left->kind != TYPE_COMPOUND_UNION) {
7370
7371                 if (is_type_valid(type_left) && !saw_error) {
7372                         errorf(&pos,
7373                                "request for member '%Y' in something not a struct or union, but '%T'",
7374                                symbol, type_left);
7375                 }
7376                 return create_invalid_expression();
7377         }
7378
7379         compound_t *compound = type_left->compound.compound;
7380         if (!compound->complete) {
7381                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
7382                        symbol, type_left);
7383                 return create_invalid_expression();
7384         }
7385
7386         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
7387         expression_t      *result     =
7388                 find_create_select(&pos, addr, qualifiers, compound, symbol);
7389
7390         if (result == NULL) {
7391                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
7392                 return create_invalid_expression();
7393         }
7394
7395         return result;
7396 }
7397
7398 static void check_call_argument(type_t          *expected_type,
7399                                 call_argument_t *argument, unsigned pos)
7400 {
7401         type_t         *expected_type_skip = skip_typeref(expected_type);
7402         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
7403         expression_t   *arg_expr           = argument->expression;
7404         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
7405
7406         /* handle transparent union gnu extension */
7407         if (is_type_union(expected_type_skip)
7408                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
7409                 compound_t *union_decl  = expected_type_skip->compound.compound;
7410                 type_t     *best_type   = NULL;
7411                 entity_t   *entry       = union_decl->members.entities;
7412                 for ( ; entry != NULL; entry = entry->base.next) {
7413                         assert(is_declaration(entry));
7414                         type_t *decl_type = entry->declaration.type;
7415                         error = semantic_assign(decl_type, arg_expr);
7416                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7417                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7418                                 continue;
7419
7420                         if (error == ASSIGN_SUCCESS) {
7421                                 best_type = decl_type;
7422                         } else if (best_type == NULL) {
7423                                 best_type = decl_type;
7424                         }
7425                 }
7426
7427                 if (best_type != NULL) {
7428                         expected_type = best_type;
7429                 }
7430         }
7431
7432         error                = semantic_assign(expected_type, arg_expr);
7433         argument->expression = create_implicit_cast(arg_expr, expected_type);
7434
7435         if (error != ASSIGN_SUCCESS) {
7436                 /* report exact scope in error messages (like "in argument 3") */
7437                 char buf[64];
7438                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7439                 report_assign_error(error, expected_type, arg_expr, buf,
7440                                     &arg_expr->base.source_position);
7441         } else if (warning.traditional || warning.conversion) {
7442                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7443                 if (!types_compatible(expected_type_skip, promoted_type) &&
7444                     !types_compatible(expected_type_skip, type_void_ptr) &&
7445                     !types_compatible(type_void_ptr,      promoted_type)) {
7446                         /* Deliberately show the skipped types in this warning */
7447                         warningf(&arg_expr->base.source_position,
7448                                 "passing call argument %u as '%T' rather than '%T' due to prototype",
7449                                 pos, expected_type_skip, promoted_type);
7450                 }
7451         }
7452 }
7453
7454 /**
7455  * Handle the semantic restrictions of builtin calls
7456  */
7457 static void handle_builtin_argument_restrictions(call_expression_t *call) {
7458         switch (call->function->reference.entity->function.btk) {
7459                 case bk_gnu_builtin_return_address:
7460                 case bk_gnu_builtin_frame_address: {
7461                         /* argument must be constant */
7462                         call_argument_t *argument = call->arguments;
7463
7464                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7465                                 errorf(&call->base.source_position,
7466                                        "argument of '%Y' must be a constant expression",
7467                                        call->function->reference.entity->base.symbol);
7468                         }
7469                         break;
7470                 }
7471                 case bk_gnu_builtin_object_size:
7472                         if (call->arguments == NULL)
7473                                 break;
7474
7475                         call_argument_t *arg = call->arguments->next;
7476                         if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7477                                 errorf(&call->base.source_position,
7478                                            "second argument of '%Y' must be a constant expression",
7479                                            call->function->reference.entity->base.symbol);
7480                         }
7481                         break;
7482                 case bk_gnu_builtin_prefetch:
7483                         /* second and third argument must be constant if existent */
7484                         if (call->arguments == NULL)
7485                                 break;
7486                         call_argument_t *rw = call->arguments->next;
7487                         call_argument_t *locality = NULL;
7488
7489                         if (rw != NULL) {
7490                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7491                                         errorf(&call->base.source_position,
7492                                                "second argument of '%Y' must be a constant expression",
7493                                                call->function->reference.entity->base.symbol);
7494                                 }
7495                                 locality = rw->next;
7496                         }
7497                         if (locality != NULL) {
7498                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7499                                         errorf(&call->base.source_position,
7500                                                "third argument of '%Y' must be a constant expression",
7501                                                call->function->reference.entity->base.symbol);
7502                                 }
7503                                 locality = rw->next;
7504                         }
7505                         break;
7506                 default:
7507                         break;
7508         }
7509 }
7510
7511 /**
7512  * Parse a call expression, ie. expression '( ... )'.
7513  *
7514  * @param expression  the function address
7515  */
7516 static expression_t *parse_call_expression(expression_t *expression)
7517 {
7518         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7519         call_expression_t *call   = &result->call;
7520         call->function            = expression;
7521
7522         type_t *const orig_type = expression->base.type;
7523         type_t *const type      = skip_typeref(orig_type);
7524
7525         function_type_t *function_type = NULL;
7526         if (is_type_pointer(type)) {
7527                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7528
7529                 if (is_type_function(to_type)) {
7530                         function_type   = &to_type->function;
7531                         call->base.type = function_type->return_type;
7532                 }
7533         }
7534
7535         if (function_type == NULL && is_type_valid(type)) {
7536                 errorf(HERE,
7537                        "called object '%E' (type '%T') is not a pointer to a function",
7538                        expression, orig_type);
7539         }
7540
7541         /* parse arguments */
7542         eat('(');
7543         add_anchor_token(')');
7544         add_anchor_token(',');
7545
7546         if (token.type != ')') {
7547                 call_argument_t **anchor = &call->arguments;
7548                 do {
7549                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7550                         argument->expression = parse_assignment_expression();
7551
7552                         *anchor = argument;
7553                         anchor  = &argument->next;
7554                 } while (next_if(','));
7555         }
7556         rem_anchor_token(',');
7557         rem_anchor_token(')');
7558         expect(')', end_error);
7559
7560         if (function_type == NULL)
7561                 return result;
7562
7563         /* check type and count of call arguments */
7564         function_parameter_t *parameter = function_type->parameters;
7565         call_argument_t      *argument  = call->arguments;
7566         if (!function_type->unspecified_parameters) {
7567                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7568                                 parameter = parameter->next, argument = argument->next) {
7569                         check_call_argument(parameter->type, argument, ++pos);
7570                 }
7571
7572                 if (parameter != NULL) {
7573                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7574                 } else if (argument != NULL && !function_type->variadic) {
7575                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7576                 }
7577         }
7578
7579         /* do default promotion for other arguments */
7580         for (; argument != NULL; argument = argument->next) {
7581                 type_t *type = argument->expression->base.type;
7582                 if (!is_type_object(skip_typeref(type))) {
7583                         errorf(&argument->expression->base.source_position,
7584                                "call argument '%E' must not be void", argument->expression);
7585                 }
7586
7587                 type = get_default_promoted_type(type);
7588
7589                 argument->expression
7590                         = create_implicit_cast(argument->expression, type);
7591         }
7592
7593         check_format(call);
7594
7595         if (warning.aggregate_return &&
7596             is_type_compound(skip_typeref(function_type->return_type))) {
7597                 warningf(&expression->base.source_position,
7598                          "function call has aggregate value");
7599         }
7600
7601         if (expression->kind == EXPR_REFERENCE) {
7602                 reference_expression_t *reference = &expression->reference;
7603                 if (reference->entity->kind == ENTITY_FUNCTION &&
7604                     reference->entity->function.btk != bk_none)
7605                         handle_builtin_argument_restrictions(call);
7606         }
7607
7608 end_error:
7609         return result;
7610 }
7611
7612 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7613
7614 static bool same_compound_type(const type_t *type1, const type_t *type2)
7615 {
7616         return
7617                 is_type_compound(type1) &&
7618                 type1->kind == type2->kind &&
7619                 type1->compound.compound == type2->compound.compound;
7620 }
7621
7622 static expression_t const *get_reference_address(expression_t const *expr)
7623 {
7624         bool regular_take_address = true;
7625         for (;;) {
7626                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7627                         expr = expr->unary.value;
7628                 } else {
7629                         regular_take_address = false;
7630                 }
7631
7632                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7633                         break;
7634
7635                 expr = expr->unary.value;
7636         }
7637
7638         if (expr->kind != EXPR_REFERENCE)
7639                 return NULL;
7640
7641         /* special case for functions which are automatically converted to a
7642          * pointer to function without an extra TAKE_ADDRESS operation */
7643         if (!regular_take_address &&
7644                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7645                 return NULL;
7646         }
7647
7648         return expr;
7649 }
7650
7651 static void warn_reference_address_as_bool(expression_t const* expr)
7652 {
7653         if (!warning.address)
7654                 return;
7655
7656         expr = get_reference_address(expr);
7657         if (expr != NULL) {
7658                 warningf(&expr->base.source_position,
7659                          "the address of '%Y' will always evaluate as 'true'",
7660                          expr->reference.entity->base.symbol);
7661         }
7662 }
7663
7664 static void warn_assignment_in_condition(const expression_t *const expr)
7665 {
7666         if (!warning.parentheses)
7667                 return;
7668         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7669                 return;
7670         if (expr->base.parenthesized)
7671                 return;
7672         warningf(&expr->base.source_position,
7673                         "suggest parentheses around assignment used as truth value");
7674 }
7675
7676 static void semantic_condition(expression_t const *const expr,
7677                                char const *const context)
7678 {
7679         type_t *const type = skip_typeref(expr->base.type);
7680         if (is_type_scalar(type)) {
7681                 warn_reference_address_as_bool(expr);
7682                 warn_assignment_in_condition(expr);
7683         } else if (is_type_valid(type)) {
7684                 errorf(&expr->base.source_position,
7685                                 "%s must have scalar type", context);
7686         }
7687 }
7688
7689 /**
7690  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7691  *
7692  * @param expression  the conditional expression
7693  */
7694 static expression_t *parse_conditional_expression(expression_t *expression)
7695 {
7696         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7697
7698         conditional_expression_t *conditional = &result->conditional;
7699         conditional->condition                = expression;
7700
7701         eat('?');
7702         add_anchor_token(':');
7703
7704         /* §6.5.15:2  The first operand shall have scalar type. */
7705         semantic_condition(expression, "condition of conditional operator");
7706
7707         expression_t *true_expression = expression;
7708         bool          gnu_cond = false;
7709         if (GNU_MODE && token.type == ':') {
7710                 gnu_cond = true;
7711         } else {
7712                 true_expression = parse_expression();
7713         }
7714         rem_anchor_token(':');
7715         expect(':', end_error);
7716 end_error:;
7717         expression_t *false_expression =
7718                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7719
7720         type_t *const orig_true_type  = true_expression->base.type;
7721         type_t *const orig_false_type = false_expression->base.type;
7722         type_t *const true_type       = skip_typeref(orig_true_type);
7723         type_t *const false_type      = skip_typeref(orig_false_type);
7724
7725         /* 6.5.15.3 */
7726         type_t *result_type;
7727         if (is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7728                         is_type_atomic(false_type, ATOMIC_TYPE_VOID)) {
7729                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7730                 if (true_expression->kind == EXPR_UNARY_THROW) {
7731                         result_type = false_type;
7732                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7733                         result_type = true_type;
7734                 } else {
7735                         if (warning.other && (
7736                                                 !is_type_atomic(true_type,  ATOMIC_TYPE_VOID) ||
7737                                                 !is_type_atomic(false_type, ATOMIC_TYPE_VOID)
7738                                         )) {
7739                                 warningf(&conditional->base.source_position,
7740                                                 "ISO C forbids conditional expression with only one void side");
7741                         }
7742                         result_type = type_void;
7743                 }
7744         } else if (is_type_arithmetic(true_type)
7745                    && is_type_arithmetic(false_type)) {
7746                 result_type = semantic_arithmetic(true_type, false_type);
7747         } else if (same_compound_type(true_type, false_type)) {
7748                 /* just take 1 of the 2 types */
7749                 result_type = true_type;
7750         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7751                 type_t *pointer_type;
7752                 type_t *other_type;
7753                 expression_t *other_expression;
7754                 if (is_type_pointer(true_type) &&
7755                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7756                         pointer_type     = true_type;
7757                         other_type       = false_type;
7758                         other_expression = false_expression;
7759                 } else {
7760                         pointer_type     = false_type;
7761                         other_type       = true_type;
7762                         other_expression = true_expression;
7763                 }
7764
7765                 if (is_null_pointer_constant(other_expression)) {
7766                         result_type = pointer_type;
7767                 } else if (is_type_pointer(other_type)) {
7768                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7769                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7770
7771                         type_t *to;
7772                         if (is_type_atomic(to1, ATOMIC_TYPE_VOID) ||
7773                             is_type_atomic(to2, ATOMIC_TYPE_VOID)) {
7774                                 to = type_void;
7775                         } else if (types_compatible(get_unqualified_type(to1),
7776                                                     get_unqualified_type(to2))) {
7777                                 to = to1;
7778                         } else {
7779                                 if (warning.other) {
7780                                         warningf(&conditional->base.source_position,
7781                                                         "pointer types '%T' and '%T' in conditional expression are incompatible",
7782                                                         true_type, false_type);
7783                                 }
7784                                 to = type_void;
7785                         }
7786
7787                         type_t *const type =
7788                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7789                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7790                 } else if (is_type_integer(other_type)) {
7791                         if (warning.other) {
7792                                 warningf(&conditional->base.source_position,
7793                                                 "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7794                         }
7795                         result_type = pointer_type;
7796                 } else {
7797                         if (is_type_valid(other_type)) {
7798                                 type_error_incompatible("while parsing conditional",
7799                                                 &expression->base.source_position, true_type, false_type);
7800                         }
7801                         result_type = type_error_type;
7802                 }
7803         } else {
7804                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7805                         type_error_incompatible("while parsing conditional",
7806                                                 &conditional->base.source_position, true_type,
7807                                                 false_type);
7808                 }
7809                 result_type = type_error_type;
7810         }
7811
7812         conditional->true_expression
7813                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7814         conditional->false_expression
7815                 = create_implicit_cast(false_expression, result_type);
7816         conditional->base.type = result_type;
7817         return result;
7818 }
7819
7820 /**
7821  * Parse an extension expression.
7822  */
7823 static expression_t *parse_extension(void)
7824 {
7825         eat(T___extension__);
7826
7827         bool old_gcc_extension   = in_gcc_extension;
7828         in_gcc_extension         = true;
7829         expression_t *expression = parse_subexpression(PREC_UNARY);
7830         in_gcc_extension         = old_gcc_extension;
7831         return expression;
7832 }
7833
7834 /**
7835  * Parse a __builtin_classify_type() expression.
7836  */
7837 static expression_t *parse_builtin_classify_type(void)
7838 {
7839         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7840         result->base.type    = type_int;
7841
7842         eat(T___builtin_classify_type);
7843
7844         expect('(', end_error);
7845         add_anchor_token(')');
7846         expression_t *expression = parse_expression();
7847         rem_anchor_token(')');
7848         expect(')', end_error);
7849         result->classify_type.type_expression = expression;
7850
7851         return result;
7852 end_error:
7853         return create_invalid_expression();
7854 }
7855
7856 /**
7857  * Parse a delete expression
7858  * ISO/IEC 14882:1998(E) §5.3.5
7859  */
7860 static expression_t *parse_delete(void)
7861 {
7862         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7863         result->base.type          = type_void;
7864
7865         eat(T_delete);
7866
7867         if (next_if('[')) {
7868                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7869                 expect(']', end_error);
7870 end_error:;
7871         }
7872
7873         expression_t *const value = parse_subexpression(PREC_CAST);
7874         result->unary.value = value;
7875
7876         type_t *const type = skip_typeref(value->base.type);
7877         if (!is_type_pointer(type)) {
7878                 if (is_type_valid(type)) {
7879                         errorf(&value->base.source_position,
7880                                         "operand of delete must have pointer type");
7881                 }
7882         } else if (warning.other &&
7883                         is_type_atomic(skip_typeref(type->pointer.points_to), ATOMIC_TYPE_VOID)) {
7884                 warningf(&value->base.source_position,
7885                                 "deleting 'void*' is undefined");
7886         }
7887
7888         return result;
7889 }
7890
7891 /**
7892  * Parse a throw expression
7893  * ISO/IEC 14882:1998(E) §15:1
7894  */
7895 static expression_t *parse_throw(void)
7896 {
7897         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7898         result->base.type          = type_void;
7899
7900         eat(T_throw);
7901
7902         expression_t *value = NULL;
7903         switch (token.type) {
7904                 EXPRESSION_START {
7905                         value = parse_assignment_expression();
7906                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7907                         type_t *const orig_type = value->base.type;
7908                         type_t *const type      = skip_typeref(orig_type);
7909                         if (is_type_incomplete(type)) {
7910                                 errorf(&value->base.source_position,
7911                                                 "cannot throw object of incomplete type '%T'", orig_type);
7912                         } else if (is_type_pointer(type)) {
7913                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7914                                 if (is_type_incomplete(points_to) &&
7915                                                 !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7916                                         errorf(&value->base.source_position,
7917                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7918                                 }
7919                         }
7920                 }
7921
7922                 default:
7923                         break;
7924         }
7925         result->unary.value = value;
7926
7927         return result;
7928 }
7929
7930 static bool check_pointer_arithmetic(const source_position_t *source_position,
7931                                      type_t *pointer_type,
7932                                      type_t *orig_pointer_type)
7933 {
7934         type_t *points_to = pointer_type->pointer.points_to;
7935         points_to = skip_typeref(points_to);
7936
7937         if (is_type_incomplete(points_to)) {
7938                 if (!GNU_MODE || !is_type_atomic(points_to, ATOMIC_TYPE_VOID)) {
7939                         errorf(source_position,
7940                                "arithmetic with pointer to incomplete type '%T' not allowed",
7941                                orig_pointer_type);
7942                         return false;
7943                 } else if (warning.pointer_arith) {
7944                         warningf(source_position,
7945                                  "pointer of type '%T' used in arithmetic",
7946                                  orig_pointer_type);
7947                 }
7948         } else if (is_type_function(points_to)) {
7949                 if (!GNU_MODE) {
7950                         errorf(source_position,
7951                                "arithmetic with pointer to function type '%T' not allowed",
7952                                orig_pointer_type);
7953                         return false;
7954                 } else if (warning.pointer_arith) {
7955                         warningf(source_position,
7956                                  "pointer to a function '%T' used in arithmetic",
7957                                  orig_pointer_type);
7958                 }
7959         }
7960         return true;
7961 }
7962
7963 static bool is_lvalue(const expression_t *expression)
7964 {
7965         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7966         switch (expression->kind) {
7967         case EXPR_ARRAY_ACCESS:
7968         case EXPR_COMPOUND_LITERAL:
7969         case EXPR_REFERENCE:
7970         case EXPR_SELECT:
7971         case EXPR_UNARY_DEREFERENCE:
7972                 return true;
7973
7974         default: {
7975                 type_t *type = skip_typeref(expression->base.type);
7976                 return
7977                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7978                         is_type_reference(type) ||
7979                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7980                          * error before, which maybe prevented properly recognizing it as
7981                          * lvalue. */
7982                         !is_type_valid(type);
7983         }
7984         }
7985 }
7986
7987 static void semantic_incdec(unary_expression_t *expression)
7988 {
7989         type_t *const orig_type = expression->value->base.type;
7990         type_t *const type      = skip_typeref(orig_type);
7991         if (is_type_pointer(type)) {
7992                 if (!check_pointer_arithmetic(&expression->base.source_position,
7993                                               type, orig_type)) {
7994                         return;
7995                 }
7996         } else if (!is_type_real(type) && is_type_valid(type)) {
7997                 /* TODO: improve error message */
7998                 errorf(&expression->base.source_position,
7999                        "operation needs an arithmetic or pointer type");
8000                 return;
8001         }
8002         if (!is_lvalue(expression->value)) {
8003                 /* TODO: improve error message */
8004                 errorf(&expression->base.source_position, "lvalue required as operand");
8005         }
8006         expression->base.type = orig_type;
8007 }
8008
8009 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
8010 {
8011         type_t *const orig_type = expression->value->base.type;
8012         type_t *const type      = skip_typeref(orig_type);
8013         if (!is_type_arithmetic(type)) {
8014                 if (is_type_valid(type)) {
8015                         /* TODO: improve error message */
8016                         errorf(&expression->base.source_position,
8017                                 "operation needs an arithmetic type");
8018                 }
8019                 return;
8020         }
8021
8022         expression->base.type = orig_type;
8023 }
8024
8025 static void semantic_unexpr_plus(unary_expression_t *expression)
8026 {
8027         semantic_unexpr_arithmetic(expression);
8028         if (warning.traditional)
8029                 warningf(&expression->base.source_position,
8030                         "traditional C rejects the unary plus operator");
8031 }
8032
8033 static void semantic_not(unary_expression_t *expression)
8034 {
8035         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
8036         semantic_condition(expression->value, "operand of !");
8037         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8038 }
8039
8040 static void semantic_unexpr_integer(unary_expression_t *expression)
8041 {
8042         type_t *const orig_type = expression->value->base.type;
8043         type_t *const type      = skip_typeref(orig_type);
8044         if (!is_type_integer(type)) {
8045                 if (is_type_valid(type)) {
8046                         errorf(&expression->base.source_position,
8047                                "operand of ~ must be of integer type");
8048                 }
8049                 return;
8050         }
8051
8052         expression->base.type = orig_type;
8053 }
8054
8055 static void semantic_dereference(unary_expression_t *expression)
8056 {
8057         type_t *const orig_type = expression->value->base.type;
8058         type_t *const type      = skip_typeref(orig_type);
8059         if (!is_type_pointer(type)) {
8060                 if (is_type_valid(type)) {
8061                         errorf(&expression->base.source_position,
8062                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
8063                 }
8064                 return;
8065         }
8066
8067         type_t *result_type   = type->pointer.points_to;
8068         result_type           = automatic_type_conversion(result_type);
8069         expression->base.type = result_type;
8070 }
8071
8072 /**
8073  * Record that an address is taken (expression represents an lvalue).
8074  *
8075  * @param expression       the expression
8076  * @param may_be_register  if true, the expression might be an register
8077  */
8078 static void set_address_taken(expression_t *expression, bool may_be_register)
8079 {
8080         if (expression->kind != EXPR_REFERENCE)
8081                 return;
8082
8083         entity_t *const entity = expression->reference.entity;
8084
8085         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
8086                 return;
8087
8088         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
8089                         && !may_be_register) {
8090                 errorf(&expression->base.source_position,
8091                        "address of register %s '%Y' requested",
8092                        get_entity_kind_name(entity->kind), entity->base.symbol);
8093         }
8094
8095         if (entity->kind == ENTITY_VARIABLE) {
8096                 entity->variable.address_taken = true;
8097         } else {
8098                 assert(entity->kind == ENTITY_PARAMETER);
8099                 entity->parameter.address_taken = true;
8100         }
8101 }
8102
8103 /**
8104  * Check the semantic of the address taken expression.
8105  */
8106 static void semantic_take_addr(unary_expression_t *expression)
8107 {
8108         expression_t *value = expression->value;
8109         value->base.type    = revert_automatic_type_conversion(value);
8110
8111         type_t *orig_type = value->base.type;
8112         type_t *type      = skip_typeref(orig_type);
8113         if (!is_type_valid(type))
8114                 return;
8115
8116         /* §6.5.3.2 */
8117         if (!is_lvalue(value)) {
8118                 errorf(&expression->base.source_position, "'&' requires an lvalue");
8119         }
8120         if (type->kind == TYPE_BITFIELD) {
8121                 errorf(&expression->base.source_position,
8122                        "'&' not allowed on object with bitfield type '%T'",
8123                        type);
8124         }
8125
8126         set_address_taken(value, false);
8127
8128         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
8129 }
8130
8131 #define CREATE_UNARY_EXPRESSION_PARSER(token_type, unexpression_type, sfunc) \
8132 static expression_t *parse_##unexpression_type(void)                         \
8133 {                                                                            \
8134         expression_t *unary_expression                                           \
8135                 = allocate_expression_zero(unexpression_type);                       \
8136         eat(token_type);                                                         \
8137         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
8138                                                                                  \
8139         sfunc(&unary_expression->unary);                                         \
8140                                                                                  \
8141         return unary_expression;                                                 \
8142 }
8143
8144 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
8145                                semantic_unexpr_arithmetic)
8146 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
8147                                semantic_unexpr_plus)
8148 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
8149                                semantic_not)
8150 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
8151                                semantic_dereference)
8152 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
8153                                semantic_take_addr)
8154 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
8155                                semantic_unexpr_integer)
8156 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
8157                                semantic_incdec)
8158 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
8159                                semantic_incdec)
8160
8161 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_type, unexpression_type, \
8162                                                sfunc)                         \
8163 static expression_t *parse_##unexpression_type(expression_t *left)            \
8164 {                                                                             \
8165         expression_t *unary_expression                                            \
8166                 = allocate_expression_zero(unexpression_type);                        \
8167         eat(token_type);                                                          \
8168         unary_expression->unary.value = left;                                     \
8169                                                                                   \
8170         sfunc(&unary_expression->unary);                                          \
8171                                                                               \
8172         return unary_expression;                                                  \
8173 }
8174
8175 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
8176                                        EXPR_UNARY_POSTFIX_INCREMENT,
8177                                        semantic_incdec)
8178 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
8179                                        EXPR_UNARY_POSTFIX_DECREMENT,
8180                                        semantic_incdec)
8181
8182 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
8183 {
8184         /* TODO: handle complex + imaginary types */
8185
8186         type_left  = get_unqualified_type(type_left);
8187         type_right = get_unqualified_type(type_right);
8188
8189         /* §6.3.1.8 Usual arithmetic conversions */
8190         if (type_left == type_long_double || type_right == type_long_double) {
8191                 return type_long_double;
8192         } else if (type_left == type_double || type_right == type_double) {
8193                 return type_double;
8194         } else if (type_left == type_float || type_right == type_float) {
8195                 return type_float;
8196         }
8197
8198         type_left  = promote_integer(type_left);
8199         type_right = promote_integer(type_right);
8200
8201         if (type_left == type_right)
8202                 return type_left;
8203
8204         bool const signed_left  = is_type_signed(type_left);
8205         bool const signed_right = is_type_signed(type_right);
8206         int const  rank_left    = get_rank(type_left);
8207         int const  rank_right   = get_rank(type_right);
8208
8209         if (signed_left == signed_right)
8210                 return rank_left >= rank_right ? type_left : type_right;
8211
8212         int     s_rank;
8213         int     u_rank;
8214         type_t *s_type;
8215         type_t *u_type;
8216         if (signed_left) {
8217                 s_rank = rank_left;
8218                 s_type = type_left;
8219                 u_rank = rank_right;
8220                 u_type = type_right;
8221         } else {
8222                 s_rank = rank_right;
8223                 s_type = type_right;
8224                 u_rank = rank_left;
8225                 u_type = type_left;
8226         }
8227
8228         if (u_rank >= s_rank)
8229                 return u_type;
8230
8231         /* casting rank to atomic_type_kind is a bit hacky, but makes things
8232          * easier here... */
8233         if (get_atomic_type_size((atomic_type_kind_t) s_rank)
8234                         > get_atomic_type_size((atomic_type_kind_t) u_rank))
8235                 return s_type;
8236
8237         switch (s_rank) {
8238                 case ATOMIC_TYPE_INT:      return type_unsigned_int;
8239                 case ATOMIC_TYPE_LONG:     return type_unsigned_long;
8240                 case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
8241
8242                 default: panic("invalid atomic type");
8243         }
8244 }
8245
8246 /**
8247  * Check the semantic restrictions for a binary expression.
8248  */
8249 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
8250 {
8251         expression_t *const left            = expression->left;
8252         expression_t *const right           = expression->right;
8253         type_t       *const orig_type_left  = left->base.type;
8254         type_t       *const orig_type_right = right->base.type;
8255         type_t       *const type_left       = skip_typeref(orig_type_left);
8256         type_t       *const type_right      = skip_typeref(orig_type_right);
8257
8258         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8259                 /* TODO: improve error message */
8260                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8261                         errorf(&expression->base.source_position,
8262                                "operation needs arithmetic types");
8263                 }
8264                 return;
8265         }
8266
8267         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8268         expression->left      = create_implicit_cast(left, arithmetic_type);
8269         expression->right     = create_implicit_cast(right, arithmetic_type);
8270         expression->base.type = arithmetic_type;
8271 }
8272
8273 static void semantic_binexpr_integer(binary_expression_t *const expression)
8274 {
8275         expression_t *const left            = expression->left;
8276         expression_t *const right           = expression->right;
8277         type_t       *const orig_type_left  = left->base.type;
8278         type_t       *const orig_type_right = right->base.type;
8279         type_t       *const type_left       = skip_typeref(orig_type_left);
8280         type_t       *const type_right      = skip_typeref(orig_type_right);
8281
8282         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8283                 /* TODO: improve error message */
8284                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8285                         errorf(&expression->base.source_position,
8286                                "operation needs integer types");
8287                 }
8288                 return;
8289         }
8290
8291         type_t *const result_type = semantic_arithmetic(type_left, type_right);
8292         expression->left      = create_implicit_cast(left, result_type);
8293         expression->right     = create_implicit_cast(right, result_type);
8294         expression->base.type = result_type;
8295 }
8296
8297 static void warn_div_by_zero(binary_expression_t const *const expression)
8298 {
8299         if (!warning.div_by_zero ||
8300             !is_type_integer(expression->base.type))
8301                 return;
8302
8303         expression_t const *const right = expression->right;
8304         /* The type of the right operand can be different for /= */
8305         if (is_type_integer(right->base.type)                    &&
8306             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
8307             !fold_constant_to_bool(right)) {
8308                 warningf(&expression->base.source_position, "division by zero");
8309         }
8310 }
8311
8312 /**
8313  * Check the semantic restrictions for a div/mod expression.
8314  */
8315 static void semantic_divmod_arithmetic(binary_expression_t *expression)
8316 {
8317         semantic_binexpr_arithmetic(expression);
8318         warn_div_by_zero(expression);
8319 }
8320
8321 static void warn_addsub_in_shift(const expression_t *const expr)
8322 {
8323         if (expr->base.parenthesized)
8324                 return;
8325
8326         char op;
8327         switch (expr->kind) {
8328                 case EXPR_BINARY_ADD: op = '+'; break;
8329                 case EXPR_BINARY_SUB: op = '-'; break;
8330                 default:              return;
8331         }
8332
8333         warningf(&expr->base.source_position,
8334                         "suggest parentheses around '%c' inside shift", op);
8335 }
8336
8337 static bool semantic_shift(binary_expression_t *expression)
8338 {
8339         expression_t *const left            = expression->left;
8340         expression_t *const right           = expression->right;
8341         type_t       *const orig_type_left  = left->base.type;
8342         type_t       *const orig_type_right = right->base.type;
8343         type_t       *      type_left       = skip_typeref(orig_type_left);
8344         type_t       *      type_right      = skip_typeref(orig_type_right);
8345
8346         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8347                 /* TODO: improve error message */
8348                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8349                         errorf(&expression->base.source_position,
8350                                "operands of shift operation must have integer types");
8351                 }
8352                 return false;
8353         }
8354
8355         type_left = promote_integer(type_left);
8356
8357         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
8358                 long count = fold_constant_to_int(right);
8359                 if (count < 0) {
8360                         warningf(&right->base.source_position,
8361                                         "shift count must be non-negative");
8362                 } else if ((unsigned long)count >=
8363                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
8364                         warningf(&right->base.source_position,
8365                                         "shift count must be less than type width");
8366                 }
8367         }
8368
8369         type_right        = promote_integer(type_right);
8370         expression->right = create_implicit_cast(right, type_right);
8371
8372         return true;
8373 }
8374
8375 static void semantic_shift_op(binary_expression_t *expression)
8376 {
8377         expression_t *const left  = expression->left;
8378         expression_t *const right = expression->right;
8379
8380         if (!semantic_shift(expression))
8381                 return;
8382
8383         if (warning.parentheses) {
8384                 warn_addsub_in_shift(left);
8385                 warn_addsub_in_shift(right);
8386         }
8387
8388         type_t *const orig_type_left = left->base.type;
8389         type_t *      type_left      = skip_typeref(orig_type_left);
8390
8391         type_left             = promote_integer(type_left);
8392         expression->left      = create_implicit_cast(left, type_left);
8393         expression->base.type = type_left;
8394 }
8395
8396 static void semantic_add(binary_expression_t *expression)
8397 {
8398         expression_t *const left            = expression->left;
8399         expression_t *const right           = expression->right;
8400         type_t       *const orig_type_left  = left->base.type;
8401         type_t       *const orig_type_right = right->base.type;
8402         type_t       *const type_left       = skip_typeref(orig_type_left);
8403         type_t       *const type_right      = skip_typeref(orig_type_right);
8404
8405         /* §6.5.6 */
8406         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8407                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8408                 expression->left  = create_implicit_cast(left, arithmetic_type);
8409                 expression->right = create_implicit_cast(right, arithmetic_type);
8410                 expression->base.type = arithmetic_type;
8411         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8412                 check_pointer_arithmetic(&expression->base.source_position,
8413                                          type_left, orig_type_left);
8414                 expression->base.type = type_left;
8415         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
8416                 check_pointer_arithmetic(&expression->base.source_position,
8417                                          type_right, orig_type_right);
8418                 expression->base.type = type_right;
8419         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8420                 errorf(&expression->base.source_position,
8421                        "invalid operands to binary + ('%T', '%T')",
8422                        orig_type_left, orig_type_right);
8423         }
8424 }
8425
8426 static void semantic_sub(binary_expression_t *expression)
8427 {
8428         expression_t            *const left            = expression->left;
8429         expression_t            *const right           = expression->right;
8430         type_t                  *const orig_type_left  = left->base.type;
8431         type_t                  *const orig_type_right = right->base.type;
8432         type_t                  *const type_left       = skip_typeref(orig_type_left);
8433         type_t                  *const type_right      = skip_typeref(orig_type_right);
8434         source_position_t const *const pos             = &expression->base.source_position;
8435
8436         /* §5.6.5 */
8437         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8438                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8439                 expression->left        = create_implicit_cast(left, arithmetic_type);
8440                 expression->right       = create_implicit_cast(right, arithmetic_type);
8441                 expression->base.type =  arithmetic_type;
8442         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8443                 check_pointer_arithmetic(&expression->base.source_position,
8444                                          type_left, orig_type_left);
8445                 expression->base.type = type_left;
8446         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8447                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8448                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8449                 if (!types_compatible(unqual_left, unqual_right)) {
8450                         errorf(pos,
8451                                "subtracting pointers to incompatible types '%T' and '%T'",
8452                                orig_type_left, orig_type_right);
8453                 } else if (!is_type_object(unqual_left)) {
8454                         if (!is_type_atomic(unqual_left, ATOMIC_TYPE_VOID)) {
8455                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8456                                        orig_type_left);
8457                         } else if (warning.other) {
8458                                 warningf(pos, "subtracting pointers to void");
8459                         }
8460                 }
8461                 expression->base.type = type_ptrdiff_t;
8462         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8463                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8464                        orig_type_left, orig_type_right);
8465         }
8466 }
8467
8468 static void warn_string_literal_address(expression_t const* expr)
8469 {
8470         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8471                 expr = expr->unary.value;
8472                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8473                         return;
8474                 expr = expr->unary.value;
8475         }
8476
8477         if (expr->kind == EXPR_STRING_LITERAL
8478                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8479                 warningf(&expr->base.source_position,
8480                         "comparison with string literal results in unspecified behaviour");
8481         }
8482 }
8483
8484 static void warn_comparison_in_comparison(const expression_t *const expr)
8485 {
8486         if (expr->base.parenthesized)
8487                 return;
8488         switch (expr->base.kind) {
8489                 case EXPR_BINARY_LESS:
8490                 case EXPR_BINARY_GREATER:
8491                 case EXPR_BINARY_LESSEQUAL:
8492                 case EXPR_BINARY_GREATEREQUAL:
8493                 case EXPR_BINARY_NOTEQUAL:
8494                 case EXPR_BINARY_EQUAL:
8495                         warningf(&expr->base.source_position,
8496                                         "comparisons like 'x <= y < z' do not have their mathematical meaning");
8497                         break;
8498                 default:
8499                         break;
8500         }
8501 }
8502
8503 static bool maybe_negative(expression_t const *const expr)
8504 {
8505         switch (is_constant_expression(expr)) {
8506                 case EXPR_CLASS_ERROR:    return false;
8507                 case EXPR_CLASS_CONSTANT: return fold_constant_to_int(expr) < 0;
8508                 default:                  return true;
8509         }
8510 }
8511
8512 /**
8513  * Check the semantics of comparison expressions.
8514  *
8515  * @param expression   The expression to check.
8516  */
8517 static void semantic_comparison(binary_expression_t *expression)
8518 {
8519         expression_t *left  = expression->left;
8520         expression_t *right = expression->right;
8521
8522         if (warning.address) {
8523                 warn_string_literal_address(left);
8524                 warn_string_literal_address(right);
8525
8526                 expression_t const* const func_left = get_reference_address(left);
8527                 if (func_left != NULL && is_null_pointer_constant(right)) {
8528                         warningf(&expression->base.source_position,
8529                                  "the address of '%Y' will never be NULL",
8530                                  func_left->reference.entity->base.symbol);
8531                 }
8532
8533                 expression_t const* const func_right = get_reference_address(right);
8534                 if (func_right != NULL && is_null_pointer_constant(right)) {
8535                         warningf(&expression->base.source_position,
8536                                  "the address of '%Y' will never be NULL",
8537                                  func_right->reference.entity->base.symbol);
8538                 }
8539         }
8540
8541         if (warning.parentheses) {
8542                 warn_comparison_in_comparison(left);
8543                 warn_comparison_in_comparison(right);
8544         }
8545
8546         type_t *orig_type_left  = left->base.type;
8547         type_t *orig_type_right = right->base.type;
8548         type_t *type_left       = skip_typeref(orig_type_left);
8549         type_t *type_right      = skip_typeref(orig_type_right);
8550
8551         /* TODO non-arithmetic types */
8552         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8553                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8554
8555                 /* test for signed vs unsigned compares */
8556                 if (warning.sign_compare && is_type_integer(arithmetic_type)) {
8557                         bool const signed_left  = is_type_signed(type_left);
8558                         bool const signed_right = is_type_signed(type_right);
8559                         if (signed_left != signed_right) {
8560                                 /* FIXME long long needs better const folding magic */
8561                                 /* TODO check whether constant value can be represented by other type */
8562                                 if ((signed_left  && maybe_negative(left)) ||
8563                                                 (signed_right && maybe_negative(right))) {
8564                                         warningf(&expression->base.source_position,
8565                                                         "comparison between signed and unsigned");
8566                                 }
8567                         }
8568                 }
8569
8570                 expression->left        = create_implicit_cast(left, arithmetic_type);
8571                 expression->right       = create_implicit_cast(right, arithmetic_type);
8572                 expression->base.type   = arithmetic_type;
8573                 if (warning.float_equal &&
8574                     (expression->base.kind == EXPR_BINARY_EQUAL ||
8575                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8576                     is_type_float(arithmetic_type)) {
8577                         warningf(&expression->base.source_position,
8578                                  "comparing floating point with == or != is unsafe");
8579                 }
8580         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8581                 /* TODO check compatibility */
8582         } else if (is_type_pointer(type_left)) {
8583                 expression->right = create_implicit_cast(right, type_left);
8584         } else if (is_type_pointer(type_right)) {
8585                 expression->left = create_implicit_cast(left, type_right);
8586         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8587                 type_error_incompatible("invalid operands in comparison",
8588                                         &expression->base.source_position,
8589                                         type_left, type_right);
8590         }
8591         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8592 }
8593
8594 /**
8595  * Checks if a compound type has constant fields.
8596  */
8597 static bool has_const_fields(const compound_type_t *type)
8598 {
8599         compound_t *compound = type->compound;
8600         entity_t   *entry    = compound->members.entities;
8601
8602         for (; entry != NULL; entry = entry->base.next) {
8603                 if (!is_declaration(entry))
8604                         continue;
8605
8606                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8607                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8608                         return true;
8609         }
8610
8611         return false;
8612 }
8613
8614 static bool is_valid_assignment_lhs(expression_t const* const left)
8615 {
8616         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8617         type_t *const type_left      = skip_typeref(orig_type_left);
8618
8619         if (!is_lvalue(left)) {
8620                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8621                        left);
8622                 return false;
8623         }
8624
8625         if (left->kind == EXPR_REFERENCE
8626                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8627                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8628                 return false;
8629         }
8630
8631         if (is_type_array(type_left)) {
8632                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8633                 return false;
8634         }
8635         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8636                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8637                        orig_type_left);
8638                 return false;
8639         }
8640         if (is_type_incomplete(type_left)) {
8641                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8642                        left, orig_type_left);
8643                 return false;
8644         }
8645         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8646                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8647                        left, orig_type_left);
8648                 return false;
8649         }
8650
8651         return true;
8652 }
8653
8654 static void semantic_arithmetic_assign(binary_expression_t *expression)
8655 {
8656         expression_t *left            = expression->left;
8657         expression_t *right           = expression->right;
8658         type_t       *orig_type_left  = left->base.type;
8659         type_t       *orig_type_right = right->base.type;
8660
8661         if (!is_valid_assignment_lhs(left))
8662                 return;
8663
8664         type_t *type_left  = skip_typeref(orig_type_left);
8665         type_t *type_right = skip_typeref(orig_type_right);
8666
8667         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8668                 /* TODO: improve error message */
8669                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8670                         errorf(&expression->base.source_position,
8671                                "operation needs arithmetic types");
8672                 }
8673                 return;
8674         }
8675
8676         /* combined instructions are tricky. We can't create an implicit cast on
8677          * the left side, because we need the uncasted form for the store.
8678          * The ast2firm pass has to know that left_type must be right_type
8679          * for the arithmetic operation and create a cast by itself */
8680         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8681         expression->right       = create_implicit_cast(right, arithmetic_type);
8682         expression->base.type   = type_left;
8683 }
8684
8685 static void semantic_divmod_assign(binary_expression_t *expression)
8686 {
8687         semantic_arithmetic_assign(expression);
8688         warn_div_by_zero(expression);
8689 }
8690
8691 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8692 {
8693         expression_t *const left            = expression->left;
8694         expression_t *const right           = expression->right;
8695         type_t       *const orig_type_left  = left->base.type;
8696         type_t       *const orig_type_right = right->base.type;
8697         type_t       *const type_left       = skip_typeref(orig_type_left);
8698         type_t       *const type_right      = skip_typeref(orig_type_right);
8699
8700         if (!is_valid_assignment_lhs(left))
8701                 return;
8702
8703         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8704                 /* combined instructions are tricky. We can't create an implicit cast on
8705                  * the left side, because we need the uncasted form for the store.
8706                  * The ast2firm pass has to know that left_type must be right_type
8707                  * for the arithmetic operation and create a cast by itself */
8708                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8709                 expression->right     = create_implicit_cast(right, arithmetic_type);
8710                 expression->base.type = type_left;
8711         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8712                 check_pointer_arithmetic(&expression->base.source_position,
8713                                          type_left, orig_type_left);
8714                 expression->base.type = type_left;
8715         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8716                 errorf(&expression->base.source_position,
8717                        "incompatible types '%T' and '%T' in assignment",
8718                        orig_type_left, orig_type_right);
8719         }
8720 }
8721
8722 static void semantic_integer_assign(binary_expression_t *expression)
8723 {
8724         expression_t *left            = expression->left;
8725         expression_t *right           = expression->right;
8726         type_t       *orig_type_left  = left->base.type;
8727         type_t       *orig_type_right = right->base.type;
8728
8729         if (!is_valid_assignment_lhs(left))
8730                 return;
8731
8732         type_t *type_left  = skip_typeref(orig_type_left);
8733         type_t *type_right = skip_typeref(orig_type_right);
8734
8735         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8736                 /* TODO: improve error message */
8737                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8738                         errorf(&expression->base.source_position,
8739                                "operation needs integer types");
8740                 }
8741                 return;
8742         }
8743
8744         /* combined instructions are tricky. We can't create an implicit cast on
8745          * the left side, because we need the uncasted form for the store.
8746          * The ast2firm pass has to know that left_type must be right_type
8747          * for the arithmetic operation and create a cast by itself */
8748         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8749         expression->right       = create_implicit_cast(right, arithmetic_type);
8750         expression->base.type   = type_left;
8751 }
8752
8753 static void semantic_shift_assign(binary_expression_t *expression)
8754 {
8755         expression_t *left           = expression->left;
8756
8757         if (!is_valid_assignment_lhs(left))
8758                 return;
8759
8760         if (!semantic_shift(expression))
8761                 return;
8762
8763         expression->base.type = skip_typeref(left->base.type);
8764 }
8765
8766 static void warn_logical_and_within_or(const expression_t *const expr)
8767 {
8768         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8769                 return;
8770         if (expr->base.parenthesized)
8771                 return;
8772         warningf(&expr->base.source_position,
8773                         "suggest parentheses around && within ||");
8774 }
8775
8776 /**
8777  * Check the semantic restrictions of a logical expression.
8778  */
8779 static void semantic_logical_op(binary_expression_t *expression)
8780 {
8781         /* §6.5.13:2  Each of the operands shall have scalar type.
8782          * §6.5.14:2  Each of the operands shall have scalar type. */
8783         semantic_condition(expression->left,   "left operand of logical operator");
8784         semantic_condition(expression->right, "right operand of logical operator");
8785         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR &&
8786                         warning.parentheses) {
8787                 warn_logical_and_within_or(expression->left);
8788                 warn_logical_and_within_or(expression->right);
8789         }
8790         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8791 }
8792
8793 /**
8794  * Check the semantic restrictions of a binary assign expression.
8795  */
8796 static void semantic_binexpr_assign(binary_expression_t *expression)
8797 {
8798         expression_t *left           = expression->left;
8799         type_t       *orig_type_left = left->base.type;
8800
8801         if (!is_valid_assignment_lhs(left))
8802                 return;
8803
8804         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8805         report_assign_error(error, orig_type_left, expression->right,
8806                         "assignment", &left->base.source_position);
8807         expression->right = create_implicit_cast(expression->right, orig_type_left);
8808         expression->base.type = orig_type_left;
8809 }
8810
8811 /**
8812  * Determine if the outermost operation (or parts thereof) of the given
8813  * expression has no effect in order to generate a warning about this fact.
8814  * Therefore in some cases this only examines some of the operands of the
8815  * expression (see comments in the function and examples below).
8816  * Examples:
8817  *   f() + 23;    // warning, because + has no effect
8818  *   x || f();    // no warning, because x controls execution of f()
8819  *   x ? y : f(); // warning, because y has no effect
8820  *   (void)x;     // no warning to be able to suppress the warning
8821  * This function can NOT be used for an "expression has definitely no effect"-
8822  * analysis. */
8823 static bool expression_has_effect(const expression_t *const expr)
8824 {
8825         switch (expr->kind) {
8826                 case EXPR_UNKNOWN:                    break;
8827                 case EXPR_INVALID:                    return true; /* do NOT warn */
8828                 case EXPR_REFERENCE:                  return false;
8829                 case EXPR_REFERENCE_ENUM_VALUE:       return false;
8830                 case EXPR_LABEL_ADDRESS:              return false;
8831
8832                 /* suppress the warning for microsoft __noop operations */
8833                 case EXPR_LITERAL_MS_NOOP:            return true;
8834                 case EXPR_LITERAL_BOOLEAN:
8835                 case EXPR_LITERAL_CHARACTER:
8836                 case EXPR_LITERAL_WIDE_CHARACTER:
8837                 case EXPR_LITERAL_INTEGER:
8838                 case EXPR_LITERAL_INTEGER_OCTAL:
8839                 case EXPR_LITERAL_INTEGER_HEXADECIMAL:
8840                 case EXPR_LITERAL_FLOATINGPOINT:
8841                 case EXPR_LITERAL_FLOATINGPOINT_HEXADECIMAL: return false;
8842                 case EXPR_STRING_LITERAL:             return false;
8843                 case EXPR_WIDE_STRING_LITERAL:        return false;
8844
8845                 case EXPR_CALL: {
8846                         const call_expression_t *const call = &expr->call;
8847                         if (call->function->kind != EXPR_REFERENCE)
8848                                 return true;
8849
8850                         switch (call->function->reference.entity->function.btk) {
8851                                 /* FIXME: which builtins have no effect? */
8852                                 default:                      return true;
8853                         }
8854                 }
8855
8856                 /* Generate the warning if either the left or right hand side of a
8857                  * conditional expression has no effect */
8858                 case EXPR_CONDITIONAL: {
8859                         conditional_expression_t const *const cond = &expr->conditional;
8860                         expression_t             const *const t    = cond->true_expression;
8861                         return
8862                                 (t == NULL || expression_has_effect(t)) &&
8863                                 expression_has_effect(cond->false_expression);
8864                 }
8865
8866                 case EXPR_SELECT:                     return false;
8867                 case EXPR_ARRAY_ACCESS:               return false;
8868                 case EXPR_SIZEOF:                     return false;
8869                 case EXPR_CLASSIFY_TYPE:              return false;
8870                 case EXPR_ALIGNOF:                    return false;
8871
8872                 case EXPR_FUNCNAME:                   return false;
8873                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8874                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8875                 case EXPR_OFFSETOF:                   return false;
8876                 case EXPR_VA_START:                   return true;
8877                 case EXPR_VA_ARG:                     return true;
8878                 case EXPR_VA_COPY:                    return true;
8879                 case EXPR_STATEMENT:                  return true; // TODO
8880                 case EXPR_COMPOUND_LITERAL:           return false;
8881
8882                 case EXPR_UNARY_NEGATE:               return false;
8883                 case EXPR_UNARY_PLUS:                 return false;
8884                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8885                 case EXPR_UNARY_NOT:                  return false;
8886                 case EXPR_UNARY_DEREFERENCE:          return false;
8887                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8888                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8889                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8890                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8891                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8892
8893                 /* Treat void casts as if they have an effect in order to being able to
8894                  * suppress the warning */
8895                 case EXPR_UNARY_CAST: {
8896                         type_t *const type = skip_typeref(expr->base.type);
8897                         return is_type_atomic(type, ATOMIC_TYPE_VOID);
8898                 }
8899
8900                 case EXPR_UNARY_CAST_IMPLICIT:        return true;
8901                 case EXPR_UNARY_ASSUME:               return true;
8902                 case EXPR_UNARY_DELETE:               return true;
8903                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8904                 case EXPR_UNARY_THROW:                return true;
8905
8906                 case EXPR_BINARY_ADD:                 return false;
8907                 case EXPR_BINARY_SUB:                 return false;
8908                 case EXPR_BINARY_MUL:                 return false;
8909                 case EXPR_BINARY_DIV:                 return false;
8910                 case EXPR_BINARY_MOD:                 return false;
8911                 case EXPR_BINARY_EQUAL:               return false;
8912                 case EXPR_BINARY_NOTEQUAL:            return false;
8913                 case EXPR_BINARY_LESS:                return false;
8914                 case EXPR_BINARY_LESSEQUAL:           return false;
8915                 case EXPR_BINARY_GREATER:             return false;
8916                 case EXPR_BINARY_GREATEREQUAL:        return false;
8917                 case EXPR_BINARY_BITWISE_AND:         return false;
8918                 case EXPR_BINARY_BITWISE_OR:          return false;
8919                 case EXPR_BINARY_BITWISE_XOR:         return false;
8920                 case EXPR_BINARY_SHIFTLEFT:           return false;
8921                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8922                 case EXPR_BINARY_ASSIGN:              return true;
8923                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8924                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8925                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8926                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8927                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8928                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8929                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8930                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8931                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8932                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8933
8934                 /* Only examine the right hand side of && and ||, because the left hand
8935                  * side already has the effect of controlling the execution of the right
8936                  * hand side */
8937                 case EXPR_BINARY_LOGICAL_AND:
8938                 case EXPR_BINARY_LOGICAL_OR:
8939                 /* Only examine the right hand side of a comma expression, because the left
8940                  * hand side has a separate warning */
8941                 case EXPR_BINARY_COMMA:
8942                         return expression_has_effect(expr->binary.right);
8943
8944                 case EXPR_BINARY_ISGREATER:           return false;
8945                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8946                 case EXPR_BINARY_ISLESS:              return false;
8947                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8948                 case EXPR_BINARY_ISLESSGREATER:       return false;
8949                 case EXPR_BINARY_ISUNORDERED:         return false;
8950         }
8951
8952         internal_errorf(HERE, "unexpected expression");
8953 }
8954
8955 static void semantic_comma(binary_expression_t *expression)
8956 {
8957         if (warning.unused_value) {
8958                 const expression_t *const left = expression->left;
8959                 if (!expression_has_effect(left)) {
8960                         warningf(&left->base.source_position,
8961                                  "left-hand operand of comma expression has no effect");
8962                 }
8963         }
8964         expression->base.type = expression->right->base.type;
8965 }
8966
8967 /**
8968  * @param prec_r precedence of the right operand
8969  */
8970 #define CREATE_BINEXPR_PARSER(token_type, binexpression_type, prec_r, sfunc) \
8971 static expression_t *parse_##binexpression_type(expression_t *left)          \
8972 {                                                                            \
8973         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8974         binexpr->binary.left  = left;                                            \
8975         eat(token_type);                                                         \
8976                                                                              \
8977         expression_t *right = parse_subexpression(prec_r);                       \
8978                                                                              \
8979         binexpr->binary.right = right;                                           \
8980         sfunc(&binexpr->binary);                                                 \
8981                                                                              \
8982         return binexpr;                                                          \
8983 }
8984
8985 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8986 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8987 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8988 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8989 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8990 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8991 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8992 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8993 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8994 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8995 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8996 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8997 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8998 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8999 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
9000 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
9001 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
9002 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
9003 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
9004 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9005 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
9006 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
9007 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9008 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
9009 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
9010 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
9011 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9012 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
9013 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
9014 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
9015
9016
9017 static expression_t *parse_subexpression(precedence_t precedence)
9018 {
9019         if (token.type < 0) {
9020                 return expected_expression_error();
9021         }
9022
9023         expression_parser_function_t *parser
9024                 = &expression_parsers[token.type];
9025         source_position_t             source_position = token.source_position;
9026         expression_t                 *left;
9027
9028         if (parser->parser != NULL) {
9029                 left = parser->parser();
9030         } else {
9031                 left = parse_primary_expression();
9032         }
9033         assert(left != NULL);
9034         left->base.source_position = source_position;
9035
9036         while (true) {
9037                 if (token.type < 0) {
9038                         return expected_expression_error();
9039                 }
9040
9041                 parser = &expression_parsers[token.type];
9042                 if (parser->infix_parser == NULL)
9043                         break;
9044                 if (parser->infix_precedence < precedence)
9045                         break;
9046
9047                 left = parser->infix_parser(left);
9048
9049                 assert(left != NULL);
9050                 assert(left->kind != EXPR_UNKNOWN);
9051                 left->base.source_position = source_position;
9052         }
9053
9054         return left;
9055 }
9056
9057 /**
9058  * Parse an expression.
9059  */
9060 static expression_t *parse_expression(void)
9061 {
9062         return parse_subexpression(PREC_EXPRESSION);
9063 }
9064
9065 /**
9066  * Register a parser for a prefix-like operator.
9067  *
9068  * @param parser      the parser function
9069  * @param token_type  the token type of the prefix token
9070  */
9071 static void register_expression_parser(parse_expression_function parser,
9072                                        int token_type)
9073 {
9074         expression_parser_function_t *entry = &expression_parsers[token_type];
9075
9076         if (entry->parser != NULL) {
9077                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9078                 panic("trying to register multiple expression parsers for a token");
9079         }
9080         entry->parser = parser;
9081 }
9082
9083 /**
9084  * Register a parser for an infix operator with given precedence.
9085  *
9086  * @param parser      the parser function
9087  * @param token_type  the token type of the infix operator
9088  * @param precedence  the precedence of the operator
9089  */
9090 static void register_infix_parser(parse_expression_infix_function parser,
9091                                   int token_type, precedence_t precedence)
9092 {
9093         expression_parser_function_t *entry = &expression_parsers[token_type];
9094
9095         if (entry->infix_parser != NULL) {
9096                 diagnosticf("for token '%k'\n", (token_type_t)token_type);
9097                 panic("trying to register multiple infix expression parsers for a "
9098                       "token");
9099         }
9100         entry->infix_parser     = parser;
9101         entry->infix_precedence = precedence;
9102 }
9103
9104 /**
9105  * Initialize the expression parsers.
9106  */
9107 static void init_expression_parsers(void)
9108 {
9109         memset(&expression_parsers, 0, sizeof(expression_parsers));
9110
9111         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
9112         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
9113         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
9114         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
9115         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
9116         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
9117         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
9118         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
9119         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
9120         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
9121         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
9122         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
9123         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
9124         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
9125         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
9126         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
9127         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
9128         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
9129         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
9130         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
9131         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
9132         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
9133         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
9134         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
9135         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
9136         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
9137         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
9138         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
9139         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
9140         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
9141         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
9142         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
9143         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
9144         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
9145         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
9146         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
9147         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
9148
9149         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
9150         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
9151         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
9152         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
9153         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
9154         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
9155         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
9156         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
9157         register_expression_parser(parse_sizeof,                      T_sizeof);
9158         register_expression_parser(parse_alignof,                     T___alignof__);
9159         register_expression_parser(parse_extension,                   T___extension__);
9160         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
9161         register_expression_parser(parse_delete,                      T_delete);
9162         register_expression_parser(parse_throw,                       T_throw);
9163 }
9164
9165 /**
9166  * Parse a asm statement arguments specification.
9167  */
9168 static asm_argument_t *parse_asm_arguments(bool is_out)
9169 {
9170         asm_argument_t  *result = NULL;
9171         asm_argument_t **anchor = &result;
9172
9173         while (token.type == T_STRING_LITERAL || token.type == '[') {
9174                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
9175                 memset(argument, 0, sizeof(argument[0]));
9176
9177                 if (next_if('[')) {
9178                         if (token.type != T_IDENTIFIER) {
9179                                 parse_error_expected("while parsing asm argument",
9180                                                      T_IDENTIFIER, NULL);
9181                                 return NULL;
9182                         }
9183                         argument->symbol = token.symbol;
9184
9185                         expect(']', end_error);
9186                 }
9187
9188                 argument->constraints = parse_string_literals();
9189                 expect('(', end_error);
9190                 add_anchor_token(')');
9191                 expression_t *expression = parse_expression();
9192                 rem_anchor_token(')');
9193                 if (is_out) {
9194                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
9195                          * change size or type representation (e.g. int -> long is ok, but
9196                          * int -> float is not) */
9197                         if (expression->kind == EXPR_UNARY_CAST) {
9198                                 type_t      *const type = expression->base.type;
9199                                 type_kind_t  const kind = type->kind;
9200                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
9201                                         unsigned flags;
9202                                         unsigned size;
9203                                         if (kind == TYPE_ATOMIC) {
9204                                                 atomic_type_kind_t const akind = type->atomic.akind;
9205                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9206                                                 size  = get_atomic_type_size(akind);
9207                                         } else {
9208                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9209                                                 size  = get_atomic_type_size(get_intptr_kind());
9210                                         }
9211
9212                                         do {
9213                                                 expression_t *const value      = expression->unary.value;
9214                                                 type_t       *const value_type = value->base.type;
9215                                                 type_kind_t   const value_kind = value_type->kind;
9216
9217                                                 unsigned value_flags;
9218                                                 unsigned value_size;
9219                                                 if (value_kind == TYPE_ATOMIC) {
9220                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
9221                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
9222                                                         value_size  = get_atomic_type_size(value_akind);
9223                                                 } else if (value_kind == TYPE_POINTER) {
9224                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
9225                                                         value_size  = get_atomic_type_size(get_intptr_kind());
9226                                                 } else {
9227                                                         break;
9228                                                 }
9229
9230                                                 if (value_flags != flags || value_size != size)
9231                                                         break;
9232
9233                                                 expression = value;
9234                                         } while (expression->kind == EXPR_UNARY_CAST);
9235                                 }
9236                         }
9237
9238                         if (!is_lvalue(expression)) {
9239                                 errorf(&expression->base.source_position,
9240                                        "asm output argument is not an lvalue");
9241                         }
9242
9243                         if (argument->constraints.begin[0] == '=')
9244                                 determine_lhs_ent(expression, NULL);
9245                         else
9246                                 mark_vars_read(expression, NULL);
9247                 } else {
9248                         mark_vars_read(expression, NULL);
9249                 }
9250                 argument->expression = expression;
9251                 expect(')', end_error);
9252
9253                 set_address_taken(expression, true);
9254
9255                 *anchor = argument;
9256                 anchor  = &argument->next;
9257
9258                 if (!next_if(','))
9259                         break;
9260         }
9261
9262         return result;
9263 end_error:
9264         return NULL;
9265 }
9266
9267 /**
9268  * Parse a asm statement clobber specification.
9269  */
9270 static asm_clobber_t *parse_asm_clobbers(void)
9271 {
9272         asm_clobber_t *result  = NULL;
9273         asm_clobber_t **anchor = &result;
9274
9275         while (token.type == T_STRING_LITERAL) {
9276                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
9277                 clobber->clobber       = parse_string_literals();
9278
9279                 *anchor = clobber;
9280                 anchor  = &clobber->next;
9281
9282                 if (!next_if(','))
9283                         break;
9284         }
9285
9286         return result;
9287 }
9288
9289 /**
9290  * Parse an asm statement.
9291  */
9292 static statement_t *parse_asm_statement(void)
9293 {
9294         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
9295         asm_statement_t *asm_statement = &statement->asms;
9296
9297         eat(T_asm);
9298
9299         if (next_if(T_volatile))
9300                 asm_statement->is_volatile = true;
9301
9302         expect('(', end_error);
9303         add_anchor_token(')');
9304         if (token.type != T_STRING_LITERAL) {
9305                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
9306                 goto end_of_asm;
9307         }
9308         asm_statement->asm_text = parse_string_literals();
9309
9310         add_anchor_token(':');
9311         if (!next_if(':')) {
9312                 rem_anchor_token(':');
9313                 goto end_of_asm;
9314         }
9315
9316         asm_statement->outputs = parse_asm_arguments(true);
9317         if (!next_if(':')) {
9318                 rem_anchor_token(':');
9319                 goto end_of_asm;
9320         }
9321
9322         asm_statement->inputs = parse_asm_arguments(false);
9323         if (!next_if(':')) {
9324                 rem_anchor_token(':');
9325                 goto end_of_asm;
9326         }
9327         rem_anchor_token(':');
9328
9329         asm_statement->clobbers = parse_asm_clobbers();
9330
9331 end_of_asm:
9332         rem_anchor_token(')');
9333         expect(')', end_error);
9334         expect(';', end_error);
9335
9336         if (asm_statement->outputs == NULL) {
9337                 /* GCC: An 'asm' instruction without any output operands will be treated
9338                  * identically to a volatile 'asm' instruction. */
9339                 asm_statement->is_volatile = true;
9340         }
9341
9342         return statement;
9343 end_error:
9344         return create_invalid_statement();
9345 }
9346
9347 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
9348 {
9349         statement_t *inner_stmt;
9350         switch (token.type) {
9351                 case '}':
9352                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
9353                         inner_stmt = create_invalid_statement();
9354                         break;
9355
9356                 case ';':
9357                         if (label->kind == STATEMENT_LABEL) {
9358                                 /* Eat an empty statement here, to avoid the warning about an empty
9359                                  * statement after a label.  label:; is commonly used to have a label
9360                                  * before a closing brace. */
9361                                 inner_stmt = create_empty_statement();
9362                                 next_token();
9363                                 break;
9364                         }
9365                         /* FALLTHROUGH */
9366
9367                 default:
9368                         inner_stmt = parse_statement();
9369                         /* ISO/IEC 14882:1998(E) §6:1/§6.7  Declarations are statements */
9370                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9371                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
9372                         }
9373                         break;
9374         }
9375         return inner_stmt;
9376 }
9377
9378 /**
9379  * Parse a case statement.
9380  */
9381 static statement_t *parse_case_statement(void)
9382 {
9383         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9384         source_position_t *const pos       = &statement->base.source_position;
9385
9386         eat(T_case);
9387
9388         expression_t *const expression   = parse_expression();
9389         statement->case_label.expression = expression;
9390         expression_classification_t const expr_class = is_constant_expression(expression);
9391         if (expr_class != EXPR_CLASS_CONSTANT) {
9392                 if (expr_class != EXPR_CLASS_ERROR) {
9393                         errorf(pos, "case label does not reduce to an integer constant");
9394                 }
9395                 statement->case_label.is_bad = true;
9396         } else {
9397                 long const val = fold_constant_to_int(expression);
9398                 statement->case_label.first_case = val;
9399                 statement->case_label.last_case  = val;
9400         }
9401
9402         if (GNU_MODE) {
9403                 if (next_if(T_DOTDOTDOT)) {
9404                         expression_t *const end_range   = parse_expression();
9405                         statement->case_label.end_range = end_range;
9406                         expression_classification_t const end_class = is_constant_expression(end_range);
9407                         if (end_class != EXPR_CLASS_CONSTANT) {
9408                                 if (end_class != EXPR_CLASS_ERROR) {
9409                                         errorf(pos, "case range does not reduce to an integer constant");
9410                                 }
9411                                 statement->case_label.is_bad = true;
9412                         } else {
9413                                 long const val = fold_constant_to_int(end_range);
9414                                 statement->case_label.last_case = val;
9415
9416                                 if (warning.other && val < statement->case_label.first_case) {
9417                                         statement->case_label.is_empty_range = true;
9418                                         warningf(pos, "empty range specified");
9419                                 }
9420                         }
9421                 }
9422         }
9423
9424         PUSH_PARENT(statement);
9425
9426         expect(':', end_error);
9427 end_error:
9428
9429         if (current_switch != NULL) {
9430                 if (! statement->case_label.is_bad) {
9431                         /* Check for duplicate case values */
9432                         case_label_statement_t *c = &statement->case_label;
9433                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
9434                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
9435                                         continue;
9436
9437                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
9438                                         continue;
9439
9440                                 errorf(pos, "duplicate case value (previously used %P)",
9441                                        &l->base.source_position);
9442                                 break;
9443                         }
9444                 }
9445                 /* link all cases into the switch statement */
9446                 if (current_switch->last_case == NULL) {
9447                         current_switch->first_case      = &statement->case_label;
9448                 } else {
9449                         current_switch->last_case->next = &statement->case_label;
9450                 }
9451                 current_switch->last_case = &statement->case_label;
9452         } else {
9453                 errorf(pos, "case label not within a switch statement");
9454         }
9455
9456         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
9457
9458         POP_PARENT;
9459         return statement;
9460 }
9461
9462 /**
9463  * Parse a default statement.
9464  */
9465 static statement_t *parse_default_statement(void)
9466 {
9467         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9468
9469         eat(T_default);
9470
9471         PUSH_PARENT(statement);
9472
9473         expect(':', end_error);
9474 end_error:
9475
9476         if (current_switch != NULL) {
9477                 const case_label_statement_t *def_label = current_switch->default_label;
9478                 if (def_label != NULL) {
9479                         errorf(HERE, "multiple default labels in one switch (previous declared %P)",
9480                                &def_label->base.source_position);
9481                 } else {
9482                         current_switch->default_label = &statement->case_label;
9483
9484                         /* link all cases into the switch statement */
9485                         if (current_switch->last_case == NULL) {
9486                                 current_switch->first_case      = &statement->case_label;
9487                         } else {
9488                                 current_switch->last_case->next = &statement->case_label;
9489                         }
9490                         current_switch->last_case = &statement->case_label;
9491                 }
9492         } else {
9493                 errorf(&statement->base.source_position,
9494                         "'default' label not within a switch statement");
9495         }
9496
9497         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9498
9499         POP_PARENT;
9500         return statement;
9501 }
9502
9503 /**
9504  * Parse a label statement.
9505  */
9506 static statement_t *parse_label_statement(void)
9507 {
9508         assert(token.type == T_IDENTIFIER);
9509         symbol_t *symbol = token.symbol;
9510         label_t  *label  = get_label(symbol);
9511
9512         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9513         statement->label.label       = label;
9514
9515         next_token();
9516
9517         PUSH_PARENT(statement);
9518
9519         /* if statement is already set then the label is defined twice,
9520          * otherwise it was just mentioned in a goto/local label declaration so far
9521          */
9522         if (label->statement != NULL) {
9523                 errorf(HERE, "duplicate label '%Y' (declared %P)",
9524                        symbol, &label->base.source_position);
9525         } else {
9526                 label->base.source_position = token.source_position;
9527                 label->statement            = statement;
9528         }
9529
9530         eat(':');
9531
9532         statement->label.statement = parse_label_inner_statement(statement, "label");
9533
9534         /* remember the labels in a list for later checking */
9535         *label_anchor = &statement->label;
9536         label_anchor  = &statement->label.next;
9537
9538         POP_PARENT;
9539         return statement;
9540 }
9541
9542 /**
9543  * Parse an if statement.
9544  */
9545 static statement_t *parse_if(void)
9546 {
9547         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9548
9549         eat(T_if);
9550
9551         PUSH_PARENT(statement);
9552
9553         add_anchor_token('{');
9554
9555         expect('(', end_error);
9556         add_anchor_token(')');
9557         expression_t *const expr = parse_expression();
9558         statement->ifs.condition = expr;
9559         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9560          *             scalar type. */
9561         semantic_condition(expr, "condition of 'if'-statment");
9562         mark_vars_read(expr, NULL);
9563         rem_anchor_token(')');
9564         expect(')', end_error);
9565
9566 end_error:
9567         rem_anchor_token('{');
9568
9569         add_anchor_token(T_else);
9570         statement_t *const true_stmt = parse_statement();
9571         statement->ifs.true_statement = true_stmt;
9572         rem_anchor_token(T_else);
9573
9574         if (next_if(T_else)) {
9575                 statement->ifs.false_statement = parse_statement();
9576         } else if (warning.parentheses &&
9577                         true_stmt->kind == STATEMENT_IF &&
9578                         true_stmt->ifs.false_statement != NULL) {
9579                 warningf(&true_stmt->base.source_position,
9580                                 "suggest explicit braces to avoid ambiguous 'else'");
9581         }
9582
9583         POP_PARENT;
9584         return statement;
9585 }
9586
9587 /**
9588  * Check that all enums are handled in a switch.
9589  *
9590  * @param statement  the switch statement to check
9591  */
9592 static void check_enum_cases(const switch_statement_t *statement)
9593 {
9594         const type_t *type = skip_typeref(statement->expression->base.type);
9595         if (! is_type_enum(type))
9596                 return;
9597         const enum_type_t *enumt = &type->enumt;
9598
9599         /* if we have a default, no warnings */
9600         if (statement->default_label != NULL)
9601                 return;
9602
9603         /* FIXME: calculation of value should be done while parsing */
9604         /* TODO: quadratic algorithm here. Change to an n log n one */
9605         long            last_value = -1;
9606         const entity_t *entry      = enumt->enume->base.next;
9607         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9608              entry = entry->base.next) {
9609                 const expression_t *expression = entry->enum_value.value;
9610                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9611                 bool                found      = false;
9612                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9613                         if (l->expression == NULL)
9614                                 continue;
9615                         if (l->first_case <= value && value <= l->last_case) {
9616                                 found = true;
9617                                 break;
9618                         }
9619                 }
9620                 if (! found) {
9621                         warningf(&statement->base.source_position,
9622                                  "enumeration value '%Y' not handled in switch",
9623                                  entry->base.symbol);
9624                 }
9625                 last_value = value;
9626         }
9627 }
9628
9629 /**
9630  * Parse a switch statement.
9631  */
9632 static statement_t *parse_switch(void)
9633 {
9634         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9635
9636         eat(T_switch);
9637
9638         PUSH_PARENT(statement);
9639
9640         expect('(', end_error);
9641         add_anchor_token(')');
9642         expression_t *const expr = parse_expression();
9643         mark_vars_read(expr, NULL);
9644         type_t       *      type = skip_typeref(expr->base.type);
9645         if (is_type_integer(type)) {
9646                 type = promote_integer(type);
9647                 if (warning.traditional) {
9648                         if (get_rank(type) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9649                                 warningf(&expr->base.source_position,
9650                                         "'%T' switch expression not converted to '%T' in ISO C",
9651                                         type, type_int);
9652                         }
9653                 }
9654         } else if (is_type_valid(type)) {
9655                 errorf(&expr->base.source_position,
9656                        "switch quantity is not an integer, but '%T'", type);
9657                 type = type_error_type;
9658         }
9659         statement->switchs.expression = create_implicit_cast(expr, type);
9660         expect(')', end_error);
9661         rem_anchor_token(')');
9662
9663         switch_statement_t *rem = current_switch;
9664         current_switch          = &statement->switchs;
9665         statement->switchs.body = parse_statement();
9666         current_switch          = rem;
9667
9668         if (warning.switch_default &&
9669             statement->switchs.default_label == NULL) {
9670                 warningf(&statement->base.source_position, "switch has no default case");
9671         }
9672         if (warning.switch_enum)
9673                 check_enum_cases(&statement->switchs);
9674
9675         POP_PARENT;
9676         return statement;
9677 end_error:
9678         POP_PARENT;
9679         return create_invalid_statement();
9680 }
9681
9682 static statement_t *parse_loop_body(statement_t *const loop)
9683 {
9684         statement_t *const rem = current_loop;
9685         current_loop = loop;
9686
9687         statement_t *const body = parse_statement();
9688
9689         current_loop = rem;
9690         return body;
9691 }
9692
9693 /**
9694  * Parse a while statement.
9695  */
9696 static statement_t *parse_while(void)
9697 {
9698         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9699
9700         eat(T_while);
9701
9702         PUSH_PARENT(statement);
9703
9704         expect('(', end_error);
9705         add_anchor_token(')');
9706         expression_t *const cond = parse_expression();
9707         statement->whiles.condition = cond;
9708         /* §6.8.5:2    The controlling expression of an iteration statement shall
9709          *             have scalar type. */
9710         semantic_condition(cond, "condition of 'while'-statement");
9711         mark_vars_read(cond, NULL);
9712         rem_anchor_token(')');
9713         expect(')', end_error);
9714
9715         statement->whiles.body = parse_loop_body(statement);
9716
9717         POP_PARENT;
9718         return statement;
9719 end_error:
9720         POP_PARENT;
9721         return create_invalid_statement();
9722 }
9723
9724 /**
9725  * Parse a do statement.
9726  */
9727 static statement_t *parse_do(void)
9728 {
9729         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9730
9731         eat(T_do);
9732
9733         PUSH_PARENT(statement);
9734
9735         add_anchor_token(T_while);
9736         statement->do_while.body = parse_loop_body(statement);
9737         rem_anchor_token(T_while);
9738
9739         expect(T_while, end_error);
9740         expect('(', end_error);
9741         add_anchor_token(')');
9742         expression_t *const cond = parse_expression();
9743         statement->do_while.condition = cond;
9744         /* §6.8.5:2    The controlling expression of an iteration statement shall
9745          *             have scalar type. */
9746         semantic_condition(cond, "condition of 'do-while'-statement");
9747         mark_vars_read(cond, NULL);
9748         rem_anchor_token(')');
9749         expect(')', end_error);
9750         expect(';', end_error);
9751
9752         POP_PARENT;
9753         return statement;
9754 end_error:
9755         POP_PARENT;
9756         return create_invalid_statement();
9757 }
9758
9759 /**
9760  * Parse a for statement.
9761  */
9762 static statement_t *parse_for(void)
9763 {
9764         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9765
9766         eat(T_for);
9767
9768         expect('(', end_error1);
9769         add_anchor_token(')');
9770
9771         PUSH_PARENT(statement);
9772
9773         size_t const  top       = environment_top();
9774         scope_t      *old_scope = scope_push(&statement->fors.scope);
9775
9776         bool old_gcc_extension = in_gcc_extension;
9777         while (next_if(T___extension__)) {
9778                 in_gcc_extension = true;
9779         }
9780
9781         if (next_if(';')) {
9782         } else if (is_declaration_specifier(&token, false)) {
9783                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9784         } else {
9785                 add_anchor_token(';');
9786                 expression_t *const init = parse_expression();
9787                 statement->fors.initialisation = init;
9788                 mark_vars_read(init, ENT_ANY);
9789                 if (warning.unused_value && !expression_has_effect(init)) {
9790                         warningf(&init->base.source_position,
9791                                         "initialisation of 'for'-statement has no effect");
9792                 }
9793                 rem_anchor_token(';');
9794                 expect(';', end_error2);
9795         }
9796         in_gcc_extension = old_gcc_extension;
9797
9798         if (token.type != ';') {
9799                 add_anchor_token(';');
9800                 expression_t *const cond = parse_expression();
9801                 statement->fors.condition = cond;
9802                 /* §6.8.5:2    The controlling expression of an iteration statement
9803                  *             shall have scalar type. */
9804                 semantic_condition(cond, "condition of 'for'-statement");
9805                 mark_vars_read(cond, NULL);
9806                 rem_anchor_token(';');
9807         }
9808         expect(';', end_error2);
9809         if (token.type != ')') {
9810                 expression_t *const step = parse_expression();
9811                 statement->fors.step = step;
9812                 mark_vars_read(step, ENT_ANY);
9813                 if (warning.unused_value && !expression_has_effect(step)) {
9814                         warningf(&step->base.source_position,
9815                                  "step of 'for'-statement has no effect");
9816                 }
9817         }
9818         expect(')', end_error2);
9819         rem_anchor_token(')');
9820         statement->fors.body = parse_loop_body(statement);
9821
9822         assert(current_scope == &statement->fors.scope);
9823         scope_pop(old_scope);
9824         environment_pop_to(top);
9825
9826         POP_PARENT;
9827         return statement;
9828
9829 end_error2:
9830         POP_PARENT;
9831         rem_anchor_token(')');
9832         assert(current_scope == &statement->fors.scope);
9833         scope_pop(old_scope);
9834         environment_pop_to(top);
9835         /* fallthrough */
9836
9837 end_error1:
9838         return create_invalid_statement();
9839 }
9840
9841 /**
9842  * Parse a goto statement.
9843  */
9844 static statement_t *parse_goto(void)
9845 {
9846         statement_t *statement = allocate_statement_zero(STATEMENT_GOTO);
9847         eat(T_goto);
9848
9849         if (GNU_MODE && next_if('*')) {
9850                 expression_t *expression = parse_expression();
9851                 mark_vars_read(expression, NULL);
9852
9853                 /* Argh: although documentation says the expression must be of type void*,
9854                  * gcc accepts anything that can be casted into void* without error */
9855                 type_t *type = expression->base.type;
9856
9857                 if (type != type_error_type) {
9858                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9859                                 errorf(&expression->base.source_position,
9860                                         "cannot convert to a pointer type");
9861                         } else if (warning.other && type != type_void_ptr) {
9862                                 warningf(&expression->base.source_position,
9863                                         "type of computed goto expression should be 'void*' not '%T'", type);
9864                         }
9865                         expression = create_implicit_cast(expression, type_void_ptr);
9866                 }
9867
9868                 statement->gotos.expression = expression;
9869         } else if (token.type == T_IDENTIFIER) {
9870                 symbol_t *symbol = token.symbol;
9871                 next_token();
9872                 statement->gotos.label = get_label(symbol);
9873         } else {
9874                 if (GNU_MODE)
9875                         parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9876                 else
9877                         parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9878                 eat_until_anchor();
9879                 return create_invalid_statement();
9880         }
9881
9882         /* remember the goto's in a list for later checking */
9883         *goto_anchor = &statement->gotos;
9884         goto_anchor  = &statement->gotos.next;
9885
9886         expect(';', end_error);
9887
9888 end_error:
9889         return statement;
9890 }
9891
9892 /**
9893  * Parse a continue statement.
9894  */
9895 static statement_t *parse_continue(void)
9896 {
9897         if (current_loop == NULL) {
9898                 errorf(HERE, "continue statement not within loop");
9899         }
9900
9901         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9902
9903         eat(T_continue);
9904         expect(';', end_error);
9905
9906 end_error:
9907         return statement;
9908 }
9909
9910 /**
9911  * Parse a break statement.
9912  */
9913 static statement_t *parse_break(void)
9914 {
9915         if (current_switch == NULL && current_loop == NULL) {
9916                 errorf(HERE, "break statement not within loop or switch");
9917         }
9918
9919         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9920
9921         eat(T_break);
9922         expect(';', end_error);
9923
9924 end_error:
9925         return statement;
9926 }
9927
9928 /**
9929  * Parse a __leave statement.
9930  */
9931 static statement_t *parse_leave_statement(void)
9932 {
9933         if (current_try == NULL) {
9934                 errorf(HERE, "__leave statement not within __try");
9935         }
9936
9937         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9938
9939         eat(T___leave);
9940         expect(';', end_error);
9941
9942 end_error:
9943         return statement;
9944 }
9945
9946 /**
9947  * Check if a given entity represents a local variable.
9948  */
9949 static bool is_local_variable(const entity_t *entity)
9950 {
9951         if (entity->kind != ENTITY_VARIABLE)
9952                 return false;
9953
9954         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9955         case STORAGE_CLASS_AUTO:
9956         case STORAGE_CLASS_REGISTER: {
9957                 const type_t *type = skip_typeref(entity->declaration.type);
9958                 if (is_type_function(type)) {
9959                         return false;
9960                 } else {
9961                         return true;
9962                 }
9963         }
9964         default:
9965                 return false;
9966         }
9967 }
9968
9969 /**
9970  * Check if a given expression represents a local variable.
9971  */
9972 static bool expression_is_local_variable(const expression_t *expression)
9973 {
9974         if (expression->base.kind != EXPR_REFERENCE) {
9975                 return false;
9976         }
9977         const entity_t *entity = expression->reference.entity;
9978         return is_local_variable(entity);
9979 }
9980
9981 /**
9982  * Check if a given expression represents a local variable and
9983  * return its declaration then, else return NULL.
9984  */
9985 entity_t *expression_is_variable(const expression_t *expression)
9986 {
9987         if (expression->base.kind != EXPR_REFERENCE) {
9988                 return NULL;
9989         }
9990         entity_t *entity = expression->reference.entity;
9991         if (entity->kind != ENTITY_VARIABLE)
9992                 return NULL;
9993
9994         return entity;
9995 }
9996
9997 /**
9998  * Parse a return statement.
9999  */
10000 static statement_t *parse_return(void)
10001 {
10002         eat(T_return);
10003
10004         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
10005
10006         expression_t *return_value = NULL;
10007         if (token.type != ';') {
10008                 return_value = parse_expression();
10009                 mark_vars_read(return_value, NULL);
10010         }
10011
10012         const type_t *const func_type = skip_typeref(current_function->base.type);
10013         assert(is_type_function(func_type));
10014         type_t *const return_type = skip_typeref(func_type->function.return_type);
10015
10016         source_position_t const *const pos = &statement->base.source_position;
10017         if (return_value != NULL) {
10018                 type_t *return_value_type = skip_typeref(return_value->base.type);
10019
10020                 if (is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10021                         if (is_type_atomic(return_value_type, ATOMIC_TYPE_VOID)) {
10022                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
10023                                 /* Only warn in C mode, because GCC does the same */
10024                                 if (c_mode & _CXX || strict_mode) {
10025                                         errorf(pos,
10026                                                         "'return' with a value, in function returning 'void'");
10027                                 } else if (warning.other) {
10028                                         warningf(pos,
10029                                                         "'return' with a value, in function returning 'void'");
10030                                 }
10031                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10032                                 /* Only warn in C mode, because GCC does the same */
10033                                 if (strict_mode) {
10034                                         errorf(pos,
10035                                                         "'return' with expression in function returning 'void'");
10036                                 } else if (warning.other) {
10037                                         warningf(pos,
10038                                                         "'return' with expression in function returning 'void'");
10039                                 }
10040                         }
10041                 } else {
10042                         assign_error_t error = semantic_assign(return_type, return_value);
10043                         report_assign_error(error, return_type, return_value, "'return'",
10044                                             pos);
10045                 }
10046                 return_value = create_implicit_cast(return_value, return_type);
10047                 /* check for returning address of a local var */
10048                 if (warning.other && return_value != NULL
10049                     && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
10050                         const expression_t *expression = return_value->unary.value;
10051                         if (expression_is_local_variable(expression)) {
10052                                 warningf(pos, "function returns address of local variable");
10053                         }
10054                 }
10055         } else if (warning.other && !is_type_atomic(return_type, ATOMIC_TYPE_VOID)) {
10056                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
10057                 if (c_mode & _CXX || strict_mode) {
10058                         errorf(pos,
10059                                "'return' without value, in function returning non-void");
10060                 } else {
10061                         warningf(pos,
10062                                  "'return' without value, in function returning non-void");
10063                 }
10064         }
10065         statement->returns.value = return_value;
10066
10067         expect(';', end_error);
10068
10069 end_error:
10070         return statement;
10071 }
10072
10073 /**
10074  * Parse a declaration statement.
10075  */
10076 static statement_t *parse_declaration_statement(void)
10077 {
10078         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10079
10080         entity_t *before = current_scope->last_entity;
10081         if (GNU_MODE) {
10082                 parse_external_declaration();
10083         } else {
10084                 parse_declaration(record_entity, DECL_FLAGS_NONE);
10085         }
10086
10087         declaration_statement_t *const decl  = &statement->declaration;
10088         entity_t                *const begin =
10089                 before != NULL ? before->base.next : current_scope->entities;
10090         decl->declarations_begin = begin;
10091         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
10092
10093         return statement;
10094 }
10095
10096 /**
10097  * Parse an expression statement, ie. expr ';'.
10098  */
10099 static statement_t *parse_expression_statement(void)
10100 {
10101         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10102
10103         expression_t *const expr         = parse_expression();
10104         statement->expression.expression = expr;
10105         mark_vars_read(expr, ENT_ANY);
10106
10107         expect(';', end_error);
10108
10109 end_error:
10110         return statement;
10111 }
10112
10113 /**
10114  * Parse a microsoft __try { } __finally { } or
10115  * __try{ } __except() { }
10116  */
10117 static statement_t *parse_ms_try_statment(void)
10118 {
10119         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
10120         eat(T___try);
10121
10122         PUSH_PARENT(statement);
10123
10124         ms_try_statement_t *rem = current_try;
10125         current_try = &statement->ms_try;
10126         statement->ms_try.try_statement = parse_compound_statement(false);
10127         current_try = rem;
10128
10129         POP_PARENT;
10130
10131         if (next_if(T___except)) {
10132                 expect('(', end_error);
10133                 add_anchor_token(')');
10134                 expression_t *const expr = parse_expression();
10135                 mark_vars_read(expr, NULL);
10136                 type_t       *      type = skip_typeref(expr->base.type);
10137                 if (is_type_integer(type)) {
10138                         type = promote_integer(type);
10139                 } else if (is_type_valid(type)) {
10140                         errorf(&expr->base.source_position,
10141                                "__expect expression is not an integer, but '%T'", type);
10142                         type = type_error_type;
10143                 }
10144                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
10145                 rem_anchor_token(')');
10146                 expect(')', end_error);
10147                 statement->ms_try.final_statement = parse_compound_statement(false);
10148         } else if (next_if(T__finally)) {
10149                 statement->ms_try.final_statement = parse_compound_statement(false);
10150         } else {
10151                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
10152                 return create_invalid_statement();
10153         }
10154         return statement;
10155 end_error:
10156         return create_invalid_statement();
10157 }
10158
10159 static statement_t *parse_empty_statement(void)
10160 {
10161         if (warning.empty_statement) {
10162                 warningf(HERE, "statement is empty");
10163         }
10164         statement_t *const statement = create_empty_statement();
10165         eat(';');
10166         return statement;
10167 }
10168
10169 static statement_t *parse_local_label_declaration(void)
10170 {
10171         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
10172
10173         eat(T___label__);
10174
10175         entity_t *begin   = NULL;
10176         entity_t *end     = NULL;
10177         entity_t **anchor = &begin;
10178         do {
10179                 if (token.type != T_IDENTIFIER) {
10180                         parse_error_expected("while parsing local label declaration",
10181                                 T_IDENTIFIER, NULL);
10182                         goto end_error;
10183                 }
10184                 symbol_t *symbol = token.symbol;
10185                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
10186                 if (entity != NULL && entity->base.parent_scope == current_scope) {
10187                         errorf(HERE, "multiple definitions of '__label__ %Y' (previous definition %P)",
10188                                symbol, &entity->base.source_position);
10189                 } else {
10190                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL);
10191
10192                         entity->base.parent_scope    = current_scope;
10193                         entity->base.namespc         = NAMESPACE_LABEL;
10194                         entity->base.source_position = token.source_position;
10195                         entity->base.symbol          = symbol;
10196
10197                         *anchor = entity;
10198                         anchor  = &entity->base.next;
10199                         end     = entity;
10200
10201                         environment_push(entity);
10202                 }
10203                 next_token();
10204         } while (next_if(','));
10205         expect(';', end_error);
10206 end_error:
10207         statement->declaration.declarations_begin = begin;
10208         statement->declaration.declarations_end   = end;
10209         return statement;
10210 }
10211
10212 static void parse_namespace_definition(void)
10213 {
10214         eat(T_namespace);
10215
10216         entity_t *entity = NULL;
10217         symbol_t *symbol = NULL;
10218
10219         if (token.type == T_IDENTIFIER) {
10220                 symbol = token.symbol;
10221                 next_token();
10222
10223                 entity = get_entity(symbol, NAMESPACE_NORMAL);
10224                 if (entity != NULL
10225                                 && entity->kind != ENTITY_NAMESPACE
10226                                 && entity->base.parent_scope == current_scope) {
10227                         if (is_entity_valid(entity)) {
10228                                 error_redefined_as_different_kind(&token.source_position,
10229                                                 entity, ENTITY_NAMESPACE);
10230                         }
10231                         entity = NULL;
10232                 }
10233         }
10234
10235         if (entity == NULL) {
10236                 entity                       = allocate_entity_zero(ENTITY_NAMESPACE);
10237                 entity->base.symbol          = symbol;
10238                 entity->base.source_position = token.source_position;
10239                 entity->base.namespc         = NAMESPACE_NORMAL;
10240                 entity->base.parent_scope    = current_scope;
10241         }
10242
10243         if (token.type == '=') {
10244                 /* TODO: parse namespace alias */
10245                 panic("namespace alias definition not supported yet");
10246         }
10247
10248         environment_push(entity);
10249         append_entity(current_scope, entity);
10250
10251         size_t const  top       = environment_top();
10252         scope_t      *old_scope = scope_push(&entity->namespacee.members);
10253
10254         entity_t     *old_current_entity = current_entity;
10255         current_entity = entity;
10256
10257         expect('{', end_error);
10258         parse_externals();
10259         expect('}', end_error);
10260
10261 end_error:
10262         assert(current_scope == &entity->namespacee.members);
10263         assert(current_entity == entity);
10264         current_entity = old_current_entity;
10265         scope_pop(old_scope);
10266         environment_pop_to(top);
10267 }
10268
10269 /**
10270  * Parse a statement.
10271  * There's also parse_statement() which additionally checks for
10272  * "statement has no effect" warnings
10273  */
10274 static statement_t *intern_parse_statement(void)
10275 {
10276         statement_t *statement = NULL;
10277
10278         /* declaration or statement */
10279         add_anchor_token(';');
10280         switch (token.type) {
10281         case T_IDENTIFIER: {
10282                 token_type_t la1_type = (token_type_t)look_ahead(1)->type;
10283                 if (la1_type == ':') {
10284                         statement = parse_label_statement();
10285                 } else if (is_typedef_symbol(token.symbol)) {
10286                         statement = parse_declaration_statement();
10287                 } else {
10288                         /* it's an identifier, the grammar says this must be an
10289                          * expression statement. However it is common that users mistype
10290                          * declaration types, so we guess a bit here to improve robustness
10291                          * for incorrect programs */
10292                         switch (la1_type) {
10293                         case '&':
10294                         case '*':
10295                                 if (get_entity(token.symbol, NAMESPACE_NORMAL) != NULL) {
10296                         default:
10297                                         statement = parse_expression_statement();
10298                                 } else {
10299                         DECLARATION_START
10300                         case T_IDENTIFIER:
10301                                         statement = parse_declaration_statement();
10302                                 }
10303                                 break;
10304                         }
10305                 }
10306                 break;
10307         }
10308
10309         case T___extension__:
10310                 /* This can be a prefix to a declaration or an expression statement.
10311                  * We simply eat it now and parse the rest with tail recursion. */
10312                 while (next_if(T___extension__)) {}
10313                 bool old_gcc_extension = in_gcc_extension;
10314                 in_gcc_extension       = true;
10315                 statement = intern_parse_statement();
10316                 in_gcc_extension = old_gcc_extension;
10317                 break;
10318
10319         DECLARATION_START
10320                 statement = parse_declaration_statement();
10321                 break;
10322
10323         case T___label__:
10324                 statement = parse_local_label_declaration();
10325                 break;
10326
10327         case ';':         statement = parse_empty_statement();         break;
10328         case '{':         statement = parse_compound_statement(false); break;
10329         case T___leave:   statement = parse_leave_statement();         break;
10330         case T___try:     statement = parse_ms_try_statment();         break;
10331         case T_asm:       statement = parse_asm_statement();           break;
10332         case T_break:     statement = parse_break();                   break;
10333         case T_case:      statement = parse_case_statement();          break;
10334         case T_continue:  statement = parse_continue();                break;
10335         case T_default:   statement = parse_default_statement();       break;
10336         case T_do:        statement = parse_do();                      break;
10337         case T_for:       statement = parse_for();                     break;
10338         case T_goto:      statement = parse_goto();                    break;
10339         case T_if:        statement = parse_if();                      break;
10340         case T_return:    statement = parse_return();                  break;
10341         case T_switch:    statement = parse_switch();                  break;
10342         case T_while:     statement = parse_while();                   break;
10343
10344         EXPRESSION_START
10345                 statement = parse_expression_statement();
10346                 break;
10347
10348         default:
10349                 errorf(HERE, "unexpected token %K while parsing statement", &token);
10350                 statement = create_invalid_statement();
10351                 if (!at_anchor())
10352                         next_token();
10353                 break;
10354         }
10355         rem_anchor_token(';');
10356
10357         assert(statement != NULL
10358                         && statement->base.source_position.input_name != NULL);
10359
10360         return statement;
10361 }
10362
10363 /**
10364  * parse a statement and emits "statement has no effect" warning if needed
10365  * (This is really a wrapper around intern_parse_statement with check for 1
10366  *  single warning. It is needed, because for statement expressions we have
10367  *  to avoid the warning on the last statement)
10368  */
10369 static statement_t *parse_statement(void)
10370 {
10371         statement_t *statement = intern_parse_statement();
10372
10373         if (statement->kind == STATEMENT_EXPRESSION && warning.unused_value) {
10374                 expression_t *expression = statement->expression.expression;
10375                 if (!expression_has_effect(expression)) {
10376                         warningf(&expression->base.source_position,
10377                                         "statement has no effect");
10378                 }
10379         }
10380
10381         return statement;
10382 }
10383
10384 /**
10385  * Parse a compound statement.
10386  */
10387 static statement_t *parse_compound_statement(bool inside_expression_statement)
10388 {
10389         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
10390
10391         PUSH_PARENT(statement);
10392
10393         eat('{');
10394         add_anchor_token('}');
10395         /* tokens, which can start a statement */
10396         /* TODO MS, __builtin_FOO */
10397         add_anchor_token('!');
10398         add_anchor_token('&');
10399         add_anchor_token('(');
10400         add_anchor_token('*');
10401         add_anchor_token('+');
10402         add_anchor_token('-');
10403         add_anchor_token('{');
10404         add_anchor_token('~');
10405         add_anchor_token(T_CHARACTER_CONSTANT);
10406         add_anchor_token(T_COLONCOLON);
10407         add_anchor_token(T_FLOATINGPOINT);
10408         add_anchor_token(T_IDENTIFIER);
10409         add_anchor_token(T_INTEGER);
10410         add_anchor_token(T_MINUSMINUS);
10411         add_anchor_token(T_PLUSPLUS);
10412         add_anchor_token(T_STRING_LITERAL);
10413         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10414         add_anchor_token(T_WIDE_STRING_LITERAL);
10415         add_anchor_token(T__Bool);
10416         add_anchor_token(T__Complex);
10417         add_anchor_token(T__Imaginary);
10418         add_anchor_token(T___FUNCTION__);
10419         add_anchor_token(T___PRETTY_FUNCTION__);
10420         add_anchor_token(T___alignof__);
10421         add_anchor_token(T___attribute__);
10422         add_anchor_token(T___builtin_va_start);
10423         add_anchor_token(T___extension__);
10424         add_anchor_token(T___func__);
10425         add_anchor_token(T___imag__);
10426         add_anchor_token(T___label__);
10427         add_anchor_token(T___real__);
10428         add_anchor_token(T___thread);
10429         add_anchor_token(T_asm);
10430         add_anchor_token(T_auto);
10431         add_anchor_token(T_bool);
10432         add_anchor_token(T_break);
10433         add_anchor_token(T_case);
10434         add_anchor_token(T_char);
10435         add_anchor_token(T_class);
10436         add_anchor_token(T_const);
10437         add_anchor_token(T_const_cast);
10438         add_anchor_token(T_continue);
10439         add_anchor_token(T_default);
10440         add_anchor_token(T_delete);
10441         add_anchor_token(T_double);
10442         add_anchor_token(T_do);
10443         add_anchor_token(T_dynamic_cast);
10444         add_anchor_token(T_enum);
10445         add_anchor_token(T_extern);
10446         add_anchor_token(T_false);
10447         add_anchor_token(T_float);
10448         add_anchor_token(T_for);
10449         add_anchor_token(T_goto);
10450         add_anchor_token(T_if);
10451         add_anchor_token(T_inline);
10452         add_anchor_token(T_int);
10453         add_anchor_token(T_long);
10454         add_anchor_token(T_new);
10455         add_anchor_token(T_operator);
10456         add_anchor_token(T_register);
10457         add_anchor_token(T_reinterpret_cast);
10458         add_anchor_token(T_restrict);
10459         add_anchor_token(T_return);
10460         add_anchor_token(T_short);
10461         add_anchor_token(T_signed);
10462         add_anchor_token(T_sizeof);
10463         add_anchor_token(T_static);
10464         add_anchor_token(T_static_cast);
10465         add_anchor_token(T_struct);
10466         add_anchor_token(T_switch);
10467         add_anchor_token(T_template);
10468         add_anchor_token(T_this);
10469         add_anchor_token(T_throw);
10470         add_anchor_token(T_true);
10471         add_anchor_token(T_try);
10472         add_anchor_token(T_typedef);
10473         add_anchor_token(T_typeid);
10474         add_anchor_token(T_typename);
10475         add_anchor_token(T_typeof);
10476         add_anchor_token(T_union);
10477         add_anchor_token(T_unsigned);
10478         add_anchor_token(T_using);
10479         add_anchor_token(T_void);
10480         add_anchor_token(T_volatile);
10481         add_anchor_token(T_wchar_t);
10482         add_anchor_token(T_while);
10483
10484         size_t const  top       = environment_top();
10485         scope_t      *old_scope = scope_push(&statement->compound.scope);
10486
10487         statement_t **anchor            = &statement->compound.statements;
10488         bool          only_decls_so_far = true;
10489         while (token.type != '}') {
10490                 if (token.type == T_EOF) {
10491                         errorf(&statement->base.source_position,
10492                                "EOF while parsing compound statement");
10493                         break;
10494                 }
10495                 statement_t *sub_statement = intern_parse_statement();
10496                 if (is_invalid_statement(sub_statement)) {
10497                         /* an error occurred. if we are at an anchor, return */
10498                         if (at_anchor())
10499                                 goto end_error;
10500                         continue;
10501                 }
10502
10503                 if (warning.declaration_after_statement) {
10504                         if (sub_statement->kind != STATEMENT_DECLARATION) {
10505                                 only_decls_so_far = false;
10506                         } else if (!only_decls_so_far) {
10507                                 warningf(&sub_statement->base.source_position,
10508                                          "ISO C90 forbids mixed declarations and code");
10509                         }
10510                 }
10511
10512                 *anchor = sub_statement;
10513
10514                 while (sub_statement->base.next != NULL)
10515                         sub_statement = sub_statement->base.next;
10516
10517                 anchor = &sub_statement->base.next;
10518         }
10519         next_token();
10520
10521         /* look over all statements again to produce no effect warnings */
10522         if (warning.unused_value) {
10523                 statement_t *sub_statement = statement->compound.statements;
10524                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
10525                         if (sub_statement->kind != STATEMENT_EXPRESSION)
10526                                 continue;
10527                         /* don't emit a warning for the last expression in an expression
10528                          * statement as it has always an effect */
10529                         if (inside_expression_statement && sub_statement->base.next == NULL)
10530                                 continue;
10531
10532                         expression_t *expression = sub_statement->expression.expression;
10533                         if (!expression_has_effect(expression)) {
10534                                 warningf(&expression->base.source_position,
10535                                          "statement has no effect");
10536                         }
10537                 }
10538         }
10539
10540 end_error:
10541         rem_anchor_token(T_while);
10542         rem_anchor_token(T_wchar_t);
10543         rem_anchor_token(T_volatile);
10544         rem_anchor_token(T_void);
10545         rem_anchor_token(T_using);
10546         rem_anchor_token(T_unsigned);
10547         rem_anchor_token(T_union);
10548         rem_anchor_token(T_typeof);
10549         rem_anchor_token(T_typename);
10550         rem_anchor_token(T_typeid);
10551         rem_anchor_token(T_typedef);
10552         rem_anchor_token(T_try);
10553         rem_anchor_token(T_true);
10554         rem_anchor_token(T_throw);
10555         rem_anchor_token(T_this);
10556         rem_anchor_token(T_template);
10557         rem_anchor_token(T_switch);
10558         rem_anchor_token(T_struct);
10559         rem_anchor_token(T_static_cast);
10560         rem_anchor_token(T_static);
10561         rem_anchor_token(T_sizeof);
10562         rem_anchor_token(T_signed);
10563         rem_anchor_token(T_short);
10564         rem_anchor_token(T_return);
10565         rem_anchor_token(T_restrict);
10566         rem_anchor_token(T_reinterpret_cast);
10567         rem_anchor_token(T_register);
10568         rem_anchor_token(T_operator);
10569         rem_anchor_token(T_new);
10570         rem_anchor_token(T_long);
10571         rem_anchor_token(T_int);
10572         rem_anchor_token(T_inline);
10573         rem_anchor_token(T_if);
10574         rem_anchor_token(T_goto);
10575         rem_anchor_token(T_for);
10576         rem_anchor_token(T_float);
10577         rem_anchor_token(T_false);
10578         rem_anchor_token(T_extern);
10579         rem_anchor_token(T_enum);
10580         rem_anchor_token(T_dynamic_cast);
10581         rem_anchor_token(T_do);
10582         rem_anchor_token(T_double);
10583         rem_anchor_token(T_delete);
10584         rem_anchor_token(T_default);
10585         rem_anchor_token(T_continue);
10586         rem_anchor_token(T_const_cast);
10587         rem_anchor_token(T_const);
10588         rem_anchor_token(T_class);
10589         rem_anchor_token(T_char);
10590         rem_anchor_token(T_case);
10591         rem_anchor_token(T_break);
10592         rem_anchor_token(T_bool);
10593         rem_anchor_token(T_auto);
10594         rem_anchor_token(T_asm);
10595         rem_anchor_token(T___thread);
10596         rem_anchor_token(T___real__);
10597         rem_anchor_token(T___label__);
10598         rem_anchor_token(T___imag__);
10599         rem_anchor_token(T___func__);
10600         rem_anchor_token(T___extension__);
10601         rem_anchor_token(T___builtin_va_start);
10602         rem_anchor_token(T___attribute__);
10603         rem_anchor_token(T___alignof__);
10604         rem_anchor_token(T___PRETTY_FUNCTION__);
10605         rem_anchor_token(T___FUNCTION__);
10606         rem_anchor_token(T__Imaginary);
10607         rem_anchor_token(T__Complex);
10608         rem_anchor_token(T__Bool);
10609         rem_anchor_token(T_WIDE_STRING_LITERAL);
10610         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10611         rem_anchor_token(T_STRING_LITERAL);
10612         rem_anchor_token(T_PLUSPLUS);
10613         rem_anchor_token(T_MINUSMINUS);
10614         rem_anchor_token(T_INTEGER);
10615         rem_anchor_token(T_IDENTIFIER);
10616         rem_anchor_token(T_FLOATINGPOINT);
10617         rem_anchor_token(T_COLONCOLON);
10618         rem_anchor_token(T_CHARACTER_CONSTANT);
10619         rem_anchor_token('~');
10620         rem_anchor_token('{');
10621         rem_anchor_token('-');
10622         rem_anchor_token('+');
10623         rem_anchor_token('*');
10624         rem_anchor_token('(');
10625         rem_anchor_token('&');
10626         rem_anchor_token('!');
10627         rem_anchor_token('}');
10628         assert(current_scope == &statement->compound.scope);
10629         scope_pop(old_scope);
10630         environment_pop_to(top);
10631
10632         POP_PARENT;
10633         return statement;
10634 }
10635
10636 /**
10637  * Check for unused global static functions and variables
10638  */
10639 static void check_unused_globals(void)
10640 {
10641         if (!warning.unused_function && !warning.unused_variable)
10642                 return;
10643
10644         for (const entity_t *entity = file_scope->entities; entity != NULL;
10645              entity = entity->base.next) {
10646                 if (!is_declaration(entity))
10647                         continue;
10648
10649                 const declaration_t *declaration = &entity->declaration;
10650                 if (declaration->used                  ||
10651                     declaration->modifiers & DM_UNUSED ||
10652                     declaration->modifiers & DM_USED   ||
10653                     declaration->storage_class != STORAGE_CLASS_STATIC)
10654                         continue;
10655
10656                 type_t *const type = declaration->type;
10657                 const char *s;
10658                 if (entity->kind == ENTITY_FUNCTION) {
10659                         /* inhibit warning for static inline functions */
10660                         if (entity->function.is_inline)
10661                                 continue;
10662
10663                         s = entity->function.statement != NULL ? "defined" : "declared";
10664                 } else {
10665                         s = "defined";
10666                 }
10667
10668                 warningf(&declaration->base.source_position, "'%#T' %s but not used",
10669                         type, declaration->base.symbol, s);
10670         }
10671 }
10672
10673 static void parse_global_asm(void)
10674 {
10675         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10676
10677         eat(T_asm);
10678         expect('(', end_error);
10679
10680         statement->asms.asm_text = parse_string_literals();
10681         statement->base.next     = unit->global_asm;
10682         unit->global_asm         = statement;
10683
10684         expect(')', end_error);
10685         expect(';', end_error);
10686
10687 end_error:;
10688 }
10689
10690 static void parse_linkage_specification(void)
10691 {
10692         eat(T_extern);
10693
10694         const char *linkage = parse_string_literals().begin;
10695
10696         linkage_kind_t old_linkage = current_linkage;
10697         linkage_kind_t new_linkage;
10698         if (strcmp(linkage, "C") == 0) {
10699                 new_linkage = LINKAGE_C;
10700         } else if (strcmp(linkage, "C++") == 0) {
10701                 new_linkage = LINKAGE_CXX;
10702         } else {
10703                 errorf(HERE, "linkage string \"%s\" not recognized", linkage);
10704                 new_linkage = LINKAGE_INVALID;
10705         }
10706         current_linkage = new_linkage;
10707
10708         if (next_if('{')) {
10709                 parse_externals();
10710                 expect('}', end_error);
10711         } else {
10712                 parse_external();
10713         }
10714
10715 end_error:
10716         assert(current_linkage == new_linkage);
10717         current_linkage = old_linkage;
10718 }
10719
10720 static void parse_external(void)
10721 {
10722         switch (token.type) {
10723                 DECLARATION_START_NO_EXTERN
10724                 case T_IDENTIFIER:
10725                 case T___extension__:
10726                 /* tokens below are for implicit int */
10727                 case '&': /* & x; -> int& x; (and error later, because C++ has no
10728                              implicit int) */
10729                 case '*': /* * x; -> int* x; */
10730                 case '(': /* (x); -> int (x); */
10731                         parse_external_declaration();
10732                         return;
10733
10734                 case T_extern:
10735                         if (look_ahead(1)->type == T_STRING_LITERAL) {
10736                                 parse_linkage_specification();
10737                         } else {
10738                                 parse_external_declaration();
10739                         }
10740                         return;
10741
10742                 case T_asm:
10743                         parse_global_asm();
10744                         return;
10745
10746                 case T_namespace:
10747                         parse_namespace_definition();
10748                         return;
10749
10750                 case ';':
10751                         if (!strict_mode) {
10752                                 if (warning.other)
10753                                         warningf(HERE, "stray ';' outside of function");
10754                                 next_token();
10755                                 return;
10756                         }
10757                         /* FALLTHROUGH */
10758
10759                 default:
10760                         errorf(HERE, "stray %K outside of function", &token);
10761                         if (token.type == '(' || token.type == '{' || token.type == '[')
10762                                 eat_until_matching_token(token.type);
10763                         next_token();
10764                         return;
10765         }
10766 }
10767
10768 static void parse_externals(void)
10769 {
10770         add_anchor_token('}');
10771         add_anchor_token(T_EOF);
10772
10773 #ifndef NDEBUG
10774         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10775         unsigned char token_anchor_copy[T_LAST_TOKEN];
10776         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10777 #endif
10778
10779         while (token.type != T_EOF && token.type != '}') {
10780 #ifndef NDEBUG
10781                 bool anchor_leak = false;
10782                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10783                         unsigned char count = token_anchor_set[i] - token_anchor_copy[i];
10784                         if (count != 0) {
10785                                 /* the anchor set and its copy differs */
10786                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10787                                 anchor_leak = true;
10788                         }
10789                 }
10790                 if (in_gcc_extension) {
10791                         /* an gcc extension scope was not closed */
10792                         internal_errorf(HERE, "Leaked __extension__");
10793                         anchor_leak = true;
10794                 }
10795
10796                 if (anchor_leak)
10797                         abort();
10798 #endif
10799
10800                 parse_external();
10801         }
10802
10803         rem_anchor_token(T_EOF);
10804         rem_anchor_token('}');
10805 }
10806
10807 /**
10808  * Parse a translation unit.
10809  */
10810 static void parse_translation_unit(void)
10811 {
10812         add_anchor_token(T_EOF);
10813
10814         while (true) {
10815                 parse_externals();
10816
10817                 if (token.type == T_EOF)
10818                         break;
10819
10820                 errorf(HERE, "stray %K outside of function", &token);
10821                 if (token.type == '(' || token.type == '{' || token.type == '[')
10822                         eat_until_matching_token(token.type);
10823                 next_token();
10824         }
10825 }
10826
10827 void set_default_visibility(elf_visibility_tag_t visibility)
10828 {
10829         default_visibility = visibility;
10830 }
10831
10832 /**
10833  * Parse the input.
10834  *
10835  * @return  the translation unit or NULL if errors occurred.
10836  */
10837 void start_parsing(void)
10838 {
10839         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10840         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10841         diagnostic_count  = 0;
10842         error_count       = 0;
10843         warning_count     = 0;
10844
10845         print_to_file(stderr);
10846
10847         assert(unit == NULL);
10848         unit = allocate_ast_zero(sizeof(unit[0]));
10849
10850         assert(file_scope == NULL);
10851         file_scope = &unit->scope;
10852
10853         assert(current_scope == NULL);
10854         scope_push(&unit->scope);
10855
10856         create_gnu_builtins();
10857         if (c_mode & _MS)
10858                 create_microsoft_intrinsics();
10859 }
10860
10861 translation_unit_t *finish_parsing(void)
10862 {
10863         assert(current_scope == &unit->scope);
10864         scope_pop(NULL);
10865
10866         assert(file_scope == &unit->scope);
10867         check_unused_globals();
10868         file_scope = NULL;
10869
10870         DEL_ARR_F(environment_stack);
10871         DEL_ARR_F(label_stack);
10872
10873         translation_unit_t *result = unit;
10874         unit = NULL;
10875         return result;
10876 }
10877
10878 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10879  * are given length one. */
10880 static void complete_incomplete_arrays(void)
10881 {
10882         size_t n = ARR_LEN(incomplete_arrays);
10883         for (size_t i = 0; i != n; ++i) {
10884                 declaration_t *const decl      = incomplete_arrays[i];
10885                 type_t        *const orig_type = decl->type;
10886                 type_t        *const type      = skip_typeref(orig_type);
10887
10888                 if (!is_type_incomplete(type))
10889                         continue;
10890
10891                 if (warning.other) {
10892                         warningf(&decl->base.source_position,
10893                                         "array '%#T' assumed to have one element",
10894                                         orig_type, decl->base.symbol);
10895                 }
10896
10897                 type_t *const new_type = duplicate_type(type);
10898                 new_type->array.size_constant     = true;
10899                 new_type->array.has_implicit_size = true;
10900                 new_type->array.size              = 1;
10901
10902                 type_t *const result = identify_new_type(new_type);
10903
10904                 decl->type = result;
10905         }
10906 }
10907
10908 void prepare_main_collect2(entity_t *entity)
10909 {
10910         // create call to __main
10911         symbol_t *symbol         = symbol_table_insert("__main");
10912         entity_t *subsubmain_ent
10913                 = create_implicit_function(symbol, &builtin_source_position);
10914
10915         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10916         type_t       *ftype       = subsubmain_ent->declaration.type;
10917         ref->base.source_position = builtin_source_position;
10918         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10919         ref->reference.entity     = subsubmain_ent;
10920
10921         expression_t *call = allocate_expression_zero(EXPR_CALL);
10922         call->base.source_position = builtin_source_position;
10923         call->base.type            = type_void;
10924         call->call.function        = ref;
10925
10926         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10927         expr_statement->base.source_position  = builtin_source_position;
10928         expr_statement->expression.expression = call;
10929
10930         statement_t *statement = entity->function.statement;
10931         assert(statement->kind == STATEMENT_COMPOUND);
10932         compound_statement_t *compounds = &statement->compound;
10933
10934         expr_statement->base.next = compounds->statements;
10935         compounds->statements     = expr_statement;
10936 }
10937
10938 void parse(void)
10939 {
10940         lookahead_bufpos = 0;
10941         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10942                 next_token();
10943         }
10944         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10945         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10946         parse_translation_unit();
10947         complete_incomplete_arrays();
10948         DEL_ARR_F(incomplete_arrays);
10949         incomplete_arrays = NULL;
10950 }
10951
10952 /**
10953  * Initialize the parser.
10954  */
10955 void init_parser(void)
10956 {
10957         sym_anonymous = symbol_table_insert("<anonymous>");
10958
10959         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10960
10961         init_expression_parsers();
10962         obstack_init(&temp_obst);
10963 }
10964
10965 /**
10966  * Terminate the parser.
10967  */
10968 void exit_parser(void)
10969 {
10970         obstack_free(&temp_obst, NULL);
10971 }