nsz Git - cparser/blob - parser.c

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