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