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 "adt/strutil.h"
  27 #include "parser.h"
  28 #include "diagnostic.h"
  29 #include "format_check.h"
  30 #include "lexer.h"
  31 #include "symbol_t.h"
  32 #include "token_t.h"
  33 #include "types.h"
  34 #include "type_t.h"
  35 #include "type_hash.h"
  36 #include "ast_t.h"
  37 #include "entity_t.h"
  38 #include "attribute_t.h"
  39 #include "lang_features.h"
  40 #include "walk.h"
  41 #include "warning.h"
  42 #include "printer.h"
  43 #include "adt/bitfiddle.h"
  44 #include "adt/error.h"
  45 #include "adt/array.h"
  46
  47 //#define PRINT_TOKENS
  48 #define MAX_LOOKAHEAD 1
  49
  50 typedef struct {
  51         entity_t           *old_entity;
  52         symbol_t           *symbol;
  53         entity_namespace_t  namespc;
  54 } stack_entry_t;
  55
  56 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  57 struct declaration_specifiers_t {
  58         source_position_t  source_position;
  59         storage_class_t    storage_class;
  60         unsigned char      alignment;         /**< Alignment, 0 if not set. */
  61         bool               is_inline    : 1;
  62         bool               thread_local : 1;  /**< GCC __thread */
  63         attribute_t       *attributes;        /**< list of attributes */
  64         type_t            *type;
  65 };
  66
  67 /**
  68  * An environment for parsing initializers (and compound literals).
  69  */
  70 typedef struct parse_initializer_env_t {
  71         type_t     *type;   /**< the type of the initializer. In case of an
  72                                  array type with unspecified size this gets
  73                                  adjusted to the actual size. */
  74         entity_t   *entity; /**< the variable that is initialized if any */
  75         bool        must_be_constant;
  76 } parse_initializer_env_t;
  77
  78 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  79
  80 /** The current token. */
  81 static token_t              token;
  82 /** The lookahead ring-buffer. */
  83 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  84 /** Position of the next token in the lookahead buffer. */
  85 static size_t               lookahead_bufpos;
  86 static stack_entry_t       *environment_stack = NULL;
  87 static stack_entry_t       *label_stack       = NULL;
  88 static scope_t             *file_scope        = NULL;
  89 static scope_t             *current_scope     = NULL;
  90 /** Point to the current function declaration if inside a function. */
  91 static function_t          *current_function  = NULL;
  92 static entity_t            *current_entity    = 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;
  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 an __extension__ context. */
 105 static bool                 in_gcc_extension  = false;
 106 static struct obstack       temp_obst;
 107 static entity_t            *anonymous_entity;
 108 static declaration_t      **incomplete_arrays;
 109 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 110
 111
 112 #define PUSH_CURRENT_ENTITY(entity) \
 113         entity_t *const new_current_entity = (entity); \
 114         entity_t *const old_current_entity = current_entity; \
 115         ((void)(current_entity = new_current_entity))
 116 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 117
 118 #define PUSH_PARENT(stmt) \
 119         statement_t *const new_parent = (stmt); \
 120         statement_t *const old_parent = current_parent; \
 121         ((void)(current_parent = new_parent))
 122 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 123
 124 #define PUSH_SCOPE(scope) \
 125         size_t   const top       = environment_top(); \
 126         scope_t *const new_scope = (scope); \
 127         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 128 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 129 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 130
 131 #define PUSH_EXTENSION() \
 132         (void)0; \
 133         bool const old_gcc_extension = in_gcc_extension; \
 134         while (next_if(T___extension__)) { \
 135                 in_gcc_extension = true; \
 136         } \
 137         do {} while (0)
 138 #define POP_EXTENSION() \
 139         ((void)(in_gcc_extension = old_gcc_extension))
 140
 141 /** special symbol used for anonymous entities. */
 142 static symbol_t *sym_anonymous = NULL;
 143
 144 /** The token anchor set */
 145 static unsigned short token_anchor_set[T_LAST_TOKEN];
 146
 147 /** The current source position. */
 148 #define HERE (&token.base.source_position)
 149
 150 /** true if we are in GCC mode. */
 151 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 152
 153 static statement_t *parse_compound_statement(bool inside_expression_statement);
 154 static statement_t *parse_statement(void);
 155
 156 static expression_t *parse_subexpression(precedence_t);
 157 static expression_t *parse_expression(void);
 158 static type_t       *parse_typename(void);
 159 static void          parse_externals(void);
 160 static void          parse_external(void);
 161
 162 static void parse_compound_type_entries(compound_t *compound_declaration);
 163
 164 static void check_call_argument(type_t          *expected_type,
 165                                                                 call_argument_t *argument, unsigned pos);
 166
 167 typedef enum declarator_flags_t {
 168         DECL_FLAGS_NONE             = 0,
 169         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 170         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 171         DECL_IS_PARAMETER           = 1U << 2
 172 } declarator_flags_t;
 173
 174 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 175                                   declarator_flags_t flags);
 176
 177 static void semantic_comparison(binary_expression_t *expression);
 178
 179 #define STORAGE_CLASSES       \
 180         STORAGE_CLASSES_NO_EXTERN \
 181         case T_extern:
 182
 183 #define STORAGE_CLASSES_NO_EXTERN \
 184         case T_typedef:         \
 185         case T_static:          \
 186         case T_auto:            \
 187         case T_register:        \
 188         case T___thread:
 189
 190 #define TYPE_QUALIFIERS     \
 191         case T_const:           \
 192         case T_restrict:        \
 193         case T_volatile:        \
 194         case T_inline:          \
 195         case T__forceinline:    \
 196         case T___attribute__:
 197
 198 #define COMPLEX_SPECIFIERS  \
 199         case T__Complex:
 200 #define IMAGINARY_SPECIFIERS \
 201         case T__Imaginary:
 202
 203 #define TYPE_SPECIFIERS       \
 204         case T__Bool:             \
 205         case T___builtin_va_list: \
 206         case T___typeof__:        \
 207         case T__declspec:         \
 208         case T_bool:              \
 209         case T_char:              \
 210         case T_double:            \
 211         case T_enum:              \
 212         case T_float:             \
 213         case T_int:               \
 214         case T_long:              \
 215         case T_short:             \
 216         case T_signed:            \
 217         case T_struct:            \
 218         case T_union:             \
 219         case T_unsigned:          \
 220         case T_void:              \
 221         case T_wchar_t:           \
 222         case T__int8:             \
 223         case T__int16:            \
 224         case T__int32:            \
 225         case T__int64:            \
 226         case T__int128:           \
 227         COMPLEX_SPECIFIERS        \
 228         IMAGINARY_SPECIFIERS
 229
 230 #define DECLARATION_START   \
 231         STORAGE_CLASSES         \
 232         TYPE_QUALIFIERS         \
 233         TYPE_SPECIFIERS
 234
 235 #define DECLARATION_START_NO_EXTERN \
 236         STORAGE_CLASSES_NO_EXTERN       \
 237         TYPE_QUALIFIERS                 \
 238         TYPE_SPECIFIERS
 239
 240 #define EXPRESSION_START              \
 241         case '!':                         \
 242         case '&':                         \
 243         case '(':                         \
 244         case '*':                         \
 245         case '+':                         \
 246         case '-':                         \
 247         case '~':                         \
 248         case T_ANDAND:                    \
 249         case T_CHARACTER_CONSTANT:        \
 250         case T_FLOATINGPOINT:             \
 251         case T_INTEGER:                   \
 252         case T_MINUSMINUS:                \
 253         case T_PLUSPLUS:                  \
 254         case T_STRING_LITERAL:            \
 255         case T_WIDE_CHARACTER_CONSTANT:   \
 256         case T_WIDE_STRING_LITERAL:       \
 257         case T___FUNCDNAME__:             \
 258         case T___FUNCSIG__:               \
 259         case T___FUNCTION__:              \
 260         case T___PRETTY_FUNCTION__:       \
 261         case T___alignof__:               \
 262         case T___builtin_classify_type:   \
 263         case T___builtin_constant_p:      \
 264         case T___builtin_isgreater:       \
 265         case T___builtin_isgreaterequal:  \
 266         case T___builtin_isless:          \
 267         case T___builtin_islessequal:     \
 268         case T___builtin_islessgreater:   \
 269         case T___builtin_isunordered:     \
 270         case T___builtin_offsetof:        \
 271         case T___builtin_va_arg:          \
 272         case T___builtin_va_copy:         \
 273         case T___builtin_va_start:        \
 274         case T___func__:                  \
 275         case T___noop:                    \
 276         case T__assume:                   \
 277         case T_delete:                    \
 278         case T_false:                     \
 279         case T_sizeof:                    \
 280         case T_throw:                     \
 281         case T_true:
 282
 283 /**
 284  * Returns the size of a statement node.
 285  *
 286  * @param kind  the statement kind
 287  */
 288 static size_t get_statement_struct_size(statement_kind_t kind)
 289 {
 290         static const size_t sizes[] = {
 291                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 292                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 293                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 294                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 295                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 296                 [STATEMENT_IF]            = sizeof(if_statement_t),
 297                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 298                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 299                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 300                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 301                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 302                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 303                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 304                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 305                 [STATEMENT_WHILE]         = sizeof(while_statement_t),
 306                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 307                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 308                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 309                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 310                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 311         };
 312         assert((size_t)kind < lengthof(sizes));
 313         assert(sizes[kind] != 0);
 314         return sizes[kind];
 315 }
 316
 317 /**
 318  * Returns the size of an expression node.
 319  *
 320  * @param kind  the expression kind
 321  */
 322 static size_t get_expression_struct_size(expression_kind_t kind)
 323 {
 324         static const size_t sizes[] = {
 325                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 326                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 327                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 328                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 329                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 330                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 331                 [EXPR_LITERAL_CHARACTER]          = sizeof(literal_expression_t),
 332                 [EXPR_LITERAL_WIDE_CHARACTER]     = sizeof(literal_expression_t),
 333                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 334                 [EXPR_WIDE_STRING_LITERAL]        = sizeof(string_literal_expression_t),
 335                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 336                 [EXPR_CALL]                       = sizeof(call_expression_t),
 337                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 338                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 339                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 340                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 341                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 342                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 343                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 344                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 345                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 346                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 347                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 348                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 349                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 350                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 351                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 352                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 353                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 354         };
 355         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 356                 return sizes[EXPR_UNARY_FIRST];
 357         }
 358         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 359                 return sizes[EXPR_BINARY_FIRST];
 360         }
 361         assert((size_t)kind < lengthof(sizes));
 362         assert(sizes[kind] != 0);
 363         return sizes[kind];
 364 }
 365
 366 /**
 367  * Allocate a statement node of given kind and initialize all
 368  * fields with zero. Sets its source position to the position
 369  * of the current token.
 370  */
 371 static statement_t *allocate_statement_zero(statement_kind_t kind)
 372 {
 373         size_t       size = get_statement_struct_size(kind);
 374         statement_t *res  = allocate_ast_zero(size);
 375
 376         res->base.kind            = kind;
 377         res->base.parent          = current_parent;
 378         res->base.source_position = *HERE;
 379         return res;
 380 }
 381
 382 /**
 383  * Allocate an expression node of given kind and initialize all
 384  * fields with zero.
 385  *
 386  * @param kind  the kind of the expression to allocate
 387  */
 388 static expression_t *allocate_expression_zero(expression_kind_t kind)
 389 {
 390         size_t        size = get_expression_struct_size(kind);
 391         expression_t *res  = allocate_ast_zero(size);
 392
 393         res->base.kind            = kind;
 394         res->base.type            = type_error_type;
 395         res->base.source_position = *HERE;
 396         return res;
 397 }
 398
 399 /**
 400  * Creates a new invalid expression at the source position
 401  * of the current token.
 402  */
 403 static expression_t *create_error_expression(void)
 404 {
 405         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 406         expression->base.type = type_error_type;
 407         return expression;
 408 }
 409
 410 /**
 411  * Creates a new invalid statement.
 412  */
 413 static statement_t *create_error_statement(void)
 414 {
 415         return allocate_statement_zero(STATEMENT_ERROR);
 416 }
 417
 418 /**
 419  * Allocate a new empty statement.
 420  */
 421 static statement_t *create_empty_statement(void)
 422 {
 423         return allocate_statement_zero(STATEMENT_EMPTY);
 424 }
 425
 426 /**
 427  * Returns the size of an initializer node.
 428  *
 429  * @param kind  the initializer kind
 430  */
 431 static size_t get_initializer_size(initializer_kind_t kind)
 432 {
 433         static const size_t sizes[] = {
 434                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 435                 [INITIALIZER_STRING]      = sizeof(initializer_string_t),
 436                 [INITIALIZER_WIDE_STRING] = sizeof(initializer_wide_string_t),
 437                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 438                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 439         };
 440         assert((size_t)kind < lengthof(sizes));
 441         assert(sizes[kind] != 0);
 442         return sizes[kind];
 443 }
 444
 445 /**
 446  * Allocate an initializer node of given kind and initialize all
 447  * fields with zero.
 448  */
 449 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 450 {
 451         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 452         result->kind          = kind;
 453
 454         return result;
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the environment stack.
 459  */
 460 static size_t environment_top(void)
 461 {
 462         return ARR_LEN(environment_stack);
 463 }
 464
 465 /**
 466  * Returns the index of the top element of the global label stack.
 467  */
 468 static size_t label_top(void)
 469 {
 470         return ARR_LEN(label_stack);
 471 }
 472
 473 /**
 474  * Return the next token.
 475  */
 476 static inline void next_token(void)
 477 {
 478         token                              = lookahead_buffer[lookahead_bufpos];
 479         lookahead_buffer[lookahead_bufpos] = lexer_token;
 480         lexer_next_token();
 481
 482         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 483
 484 #ifdef PRINT_TOKENS
 485         print_token(stderr, &token);
 486         fprintf(stderr, "\n");
 487 #endif
 488 }
 489
 490 static inline bool next_if(token_kind_t const type)
 491 {
 492         if (token.kind == type) {
 493                 next_token();
 494                 return true;
 495         } else {
 496                 return false;
 497         }
 498 }
 499
 500 /**
 501  * Return the next token with a given lookahead.
 502  */
 503 static inline const token_t *look_ahead(size_t num)
 504 {
 505         assert(0 < num && num <= MAX_LOOKAHEAD);
 506         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 507         return &lookahead_buffer[pos];
 508 }
 509
 510 /**
 511  * Adds a token type to the token type anchor set (a multi-set).
 512  */
 513 static void add_anchor_token(token_kind_t const token_kind)
 514 {
 515         assert(token_kind < T_LAST_TOKEN);
 516         ++token_anchor_set[token_kind];
 517 }
 518
 519 /**
 520  * Remove a token type from the token type anchor set (a multi-set).
 521  */
 522 static void rem_anchor_token(token_kind_t const token_kind)
 523 {
 524         assert(token_kind < T_LAST_TOKEN);
 525         assert(token_anchor_set[token_kind] != 0);
 526         --token_anchor_set[token_kind];
 527 }
 528
 529 /**
 530  * Eat tokens until a matching token type is found.
 531  */
 532 static void eat_until_matching_token(token_kind_t const type)
 533 {
 534         token_kind_t end_token;
 535         switch (type) {
 536                 case '(': end_token = ')';  break;
 537                 case '{': end_token = '}';  break;
 538                 case '[': end_token = ']';  break;
 539                 default:  end_token = type; break;
 540         }
 541
 542         unsigned parenthesis_count = 0;
 543         unsigned brace_count       = 0;
 544         unsigned bracket_count     = 0;
 545         while (token.kind        != end_token ||
 546                parenthesis_count != 0         ||
 547                brace_count       != 0         ||
 548                bracket_count     != 0) {
 549                 switch (token.kind) {
 550                 case T_EOF: return;
 551                 case '(': ++parenthesis_count; break;
 552                 case '{': ++brace_count;       break;
 553                 case '[': ++bracket_count;     break;
 554
 555                 case ')':
 556                         if (parenthesis_count > 0)
 557                                 --parenthesis_count;
 558                         goto check_stop;
 559
 560                 case '}':
 561                         if (brace_count > 0)
 562                                 --brace_count;
 563                         goto check_stop;
 564
 565                 case ']':
 566                         if (bracket_count > 0)
 567                                 --bracket_count;
 568 check_stop:
 569                         if (token.kind        == end_token &&
 570                             parenthesis_count == 0         &&
 571                             brace_count       == 0         &&
 572                             bracket_count     == 0)
 573                                 return;
 574                         break;
 575
 576                 default:
 577                         break;
 578                 }
 579                 next_token();
 580         }
 581 }
 582
 583 /**
 584  * Eat input tokens until an anchor is found.
 585  */
 586 static void eat_until_anchor(void)
 587 {
 588         while (token_anchor_set[token.kind] == 0) {
 589                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 590                         eat_until_matching_token(token.kind);
 591                 next_token();
 592         }
 593 }
 594
 595 /**
 596  * Eat a whole block from input tokens.
 597  */
 598 static void eat_block(void)
 599 {
 600         eat_until_matching_token('{');
 601         next_if('}');
 602 }
 603
 604 #define eat(token_kind) (assert(token.kind == (token_kind)), next_token())
 605
 606 /**
 607  * Report a parse error because an expected token was not found.
 608  */
 609 static
 610 #if defined __GNUC__ && __GNUC__ >= 4
 611 __attribute__((sentinel))
 612 #endif
 613 void parse_error_expected(const char *message, ...)
 614 {
 615         if (message != NULL) {
 616                 errorf(HERE, "%s", message);
 617         }
 618         va_list ap;
 619         va_start(ap, message);
 620         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 621         va_end(ap);
 622 }
 623
 624 /**
 625  * Report an incompatible type.
 626  */
 627 static void type_error_incompatible(const char *msg,
 628                 const source_position_t *source_position, type_t *type1, type_t *type2)
 629 {
 630         errorf(source_position, "%s, incompatible types: '%T' - '%T'",
 631                msg, type1, type2);
 632 }
 633
 634 /**
 635  * Expect the current token is the expected token.
 636  * If not, generate an error and skip until the next anchor.
 637  */
 638 static void expect(token_kind_t const expected)
 639 {
 640         if (UNLIKELY(token.kind != expected)) {
 641                 parse_error_expected(NULL, expected, NULL);
 642                 add_anchor_token(expected);
 643                 eat_until_anchor();
 644                 rem_anchor_token(expected);
 645                 if (token.kind != expected)
 646                         return;
 647         }
 648         eat(expected);
 649 }
 650
 651 static symbol_t *expect_identifier(char const *const context, source_position_t *const pos)
 652 {
 653         if (token.kind != T_IDENTIFIER) {
 654                 parse_error_expected(context, T_IDENTIFIER, NULL);
 655                 add_anchor_token(T_IDENTIFIER);
 656                 eat_until_anchor();
 657                 rem_anchor_token(T_IDENTIFIER);
 658                 if (token.kind != T_IDENTIFIER)
 659                         return NULL;
 660         }
 661         symbol_t *const sym = token.base.symbol;
 662         if (pos)
 663                 *pos = *HERE;
 664         eat(T_IDENTIFIER);
 665         return sym;
 666 }
 667
 668 /**
 669  * Push a given scope on the scope stack and make it the
 670  * current scope
 671  */
 672 static scope_t *scope_push(scope_t *new_scope)
 673 {
 674         if (current_scope != NULL) {
 675                 new_scope->depth = current_scope->depth + 1;
 676         }
 677
 678         scope_t *old_scope = current_scope;
 679         current_scope      = new_scope;
 680         return old_scope;
 681 }
 682
 683 /**
 684  * Pop the current scope from the scope stack.
 685  */
 686 static void scope_pop(scope_t *old_scope)
 687 {
 688         current_scope = old_scope;
 689 }
 690
 691 /**
 692  * Search an entity by its symbol in a given namespace.
 693  */
 694 static entity_t *get_entity(const symbol_t *const symbol,
 695                             namespace_tag_t namespc)
 696 {
 697         entity_t *entity = symbol->entity;
 698         for (; entity != NULL; entity = entity->base.symbol_next) {
 699                 if ((namespace_tag_t)entity->base.namespc == namespc)
 700                         return entity;
 701         }
 702
 703         return NULL;
 704 }
 705
 706 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 707  * possible. */
 708 static entity_t *get_tag(symbol_t const *const symbol,
 709                          entity_kind_tag_t const kind)
 710 {
 711         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 712         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 713                 errorf(HERE,
 714                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 715                                 symbol, &entity->base.source_position);
 716                 entity = NULL;
 717         }
 718         return entity;
 719 }
 720
 721 /**
 722  * pushs an entity on the environment stack and links the corresponding symbol
 723  * it.
 724  */
 725 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 726 {
 727         symbol_t           *symbol  = entity->base.symbol;
 728         entity_namespace_t  namespc = entity->base.namespc;
 729         assert(namespc != 0);
 730
 731         /* replace/add entity into entity list of the symbol */
 732         entity_t **anchor;
 733         entity_t  *iter;
 734         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 735                 iter = *anchor;
 736                 if (iter == NULL)
 737                         break;
 738
 739                 /* replace an entry? */
 740                 if (iter->base.namespc == namespc) {
 741                         entity->base.symbol_next = iter->base.symbol_next;
 742                         break;
 743                 }
 744         }
 745         *anchor = entity;
 746
 747         /* remember old declaration */
 748         stack_entry_t entry;
 749         entry.symbol     = symbol;
 750         entry.old_entity = iter;
 751         entry.namespc    = namespc;
 752         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 753 }
 754
 755 /**
 756  * Push an entity on the environment stack.
 757  */
 758 static void environment_push(entity_t *entity)
 759 {
 760         assert(entity->base.source_position.input_name != NULL);
 761         assert(entity->base.parent_scope != NULL);
 762         stack_push(&environment_stack, entity);
 763 }
 764
 765 /**
 766  * Push a declaration on the global label stack.
 767  *
 768  * @param declaration  the declaration
 769  */
 770 static void label_push(entity_t *label)
 771 {
 772         /* we abuse the parameters scope as parent for the labels */
 773         label->base.parent_scope = &current_function->parameters;
 774         stack_push(&label_stack, label);
 775 }
 776
 777 /**
 778  * pops symbols from the environment stack until @p new_top is the top element
 779  */
 780 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 781 {
 782         stack_entry_t *stack = *stack_ptr;
 783         size_t         top   = ARR_LEN(stack);
 784         size_t         i;
 785
 786         assert(new_top <= top);
 787         if (new_top == top)
 788                 return;
 789
 790         for (i = top; i > new_top; --i) {
 791                 stack_entry_t *entry = &stack[i - 1];
 792
 793                 entity_t           *old_entity = entry->old_entity;
 794                 symbol_t           *symbol     = entry->symbol;
 795                 entity_namespace_t  namespc    = entry->namespc;
 796
 797                 /* replace with old_entity/remove */
 798                 entity_t **anchor;
 799                 entity_t  *iter;
 800                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 801                         iter = *anchor;
 802                         assert(iter != NULL);
 803                         /* replace an entry? */
 804                         if (iter->base.namespc == namespc)
 805                                 break;
 806                 }
 807
 808                 /* restore definition from outer scopes (if there was one) */
 809                 if (old_entity != NULL) {
 810                         old_entity->base.symbol_next = iter->base.symbol_next;
 811                         *anchor                      = old_entity;
 812                 } else {
 813                         /* remove entry from list */
 814                         *anchor = iter->base.symbol_next;
 815                 }
 816         }
 817
 818         ARR_SHRINKLEN(*stack_ptr, new_top);
 819 }
 820
 821 /**
 822  * Pop all entries from the environment stack until the new_top
 823  * is reached.
 824  *
 825  * @param new_top  the new stack top
 826  */
 827 static void environment_pop_to(size_t new_top)
 828 {
 829         stack_pop_to(&environment_stack, new_top);
 830 }
 831
 832 /**
 833  * Pop all entries from the global label stack until the new_top
 834  * is reached.
 835  *
 836  * @param new_top  the new stack top
 837  */
 838 static void label_pop_to(size_t new_top)
 839 {
 840         stack_pop_to(&label_stack, new_top);
 841 }
 842
 843 static atomic_type_kind_t get_akind(const type_t *type)
 844 {
 845         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 846                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 847         return type->atomic.akind;
 848 }
 849
 850 /**
 851  * §6.3.1.1:2  Do integer promotion for a given type.
 852  *
 853  * @param type  the type to promote
 854  * @return the promoted type
 855  */
 856 static type_t *promote_integer(type_t *type)
 857 {
 858         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 859                 type = type_int;
 860
 861         return type;
 862 }
 863
 864 /**
 865  * Check if a given expression represents a null pointer constant.
 866  *
 867  * @param expression  the expression to check
 868  */
 869 static bool is_null_pointer_constant(const expression_t *expression)
 870 {
 871         /* skip void* cast */
 872         if (expression->kind == EXPR_UNARY_CAST) {
 873                 type_t *const type = skip_typeref(expression->base.type);
 874                 if (types_compatible(type, type_void_ptr))
 875                         expression = expression->unary.value;
 876         }
 877
 878         type_t *const type = skip_typeref(expression->base.type);
 879         if (!is_type_integer(type))
 880                 return false;
 881         switch (is_constant_expression(expression)) {
 882                 case EXPR_CLASS_ERROR:    return true;
 883                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 884                 default:                  return false;
 885         }
 886 }
 887
 888 /**
 889  * Create an implicit cast expression.
 890  *
 891  * @param expression  the expression to cast
 892  * @param dest_type   the destination type
 893  */
 894 static expression_t *create_implicit_cast(expression_t *expression,
 895                                           type_t *dest_type)
 896 {
 897         type_t *const source_type = expression->base.type;
 898
 899         if (source_type == dest_type)
 900                 return expression;
 901
 902         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 903         cast->unary.value   = expression;
 904         cast->base.type     = dest_type;
 905         cast->base.implicit = true;
 906
 907         return cast;
 908 }
 909
 910 typedef enum assign_error_t {
 911         ASSIGN_SUCCESS,
 912         ASSIGN_ERROR_INCOMPATIBLE,
 913         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 914         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 915         ASSIGN_WARNING_POINTER_FROM_INT,
 916         ASSIGN_WARNING_INT_FROM_POINTER
 917 } assign_error_t;
 918
 919 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)
 920 {
 921         type_t *const orig_type_right = right->base.type;
 922         type_t *const type_left       = skip_typeref(orig_type_left);
 923         type_t *const type_right      = skip_typeref(orig_type_right);
 924
 925         switch (error) {
 926         case ASSIGN_SUCCESS:
 927                 return;
 928         case ASSIGN_ERROR_INCOMPATIBLE:
 929                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 930                 return;
 931
 932         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 933                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 934                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 935
 936                 /* the left type has all qualifiers from the right type */
 937                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 938                 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);
 939                 return;
 940         }
 941
 942         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 943                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 944                 return;
 945
 946         case ASSIGN_WARNING_POINTER_FROM_INT:
 947                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 948                 return;
 949
 950         case ASSIGN_WARNING_INT_FROM_POINTER:
 951                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 952                 return;
 953
 954         default:
 955                 panic("invalid error value");
 956         }
 957 }
 958
 959 /** Implements the rules from §6.5.16.1 */
 960 static assign_error_t semantic_assign(type_t *orig_type_left,
 961                                       const expression_t *const right)
 962 {
 963         type_t *const orig_type_right = right->base.type;
 964         type_t *const type_left       = skip_typeref(orig_type_left);
 965         type_t *const type_right      = skip_typeref(orig_type_right);
 966
 967         if (is_type_pointer(type_left)) {
 968                 if (is_null_pointer_constant(right)) {
 969                         return ASSIGN_SUCCESS;
 970                 } else if (is_type_pointer(type_right)) {
 971                         type_t *points_to_left
 972                                 = skip_typeref(type_left->pointer.points_to);
 973                         type_t *points_to_right
 974                                 = skip_typeref(type_right->pointer.points_to);
 975                         assign_error_t res = ASSIGN_SUCCESS;
 976
 977                         /* the left type has all qualifiers from the right type */
 978                         unsigned missing_qualifiers
 979                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 980                         if (missing_qualifiers != 0) {
 981                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 982                         }
 983
 984                         points_to_left  = get_unqualified_type(points_to_left);
 985                         points_to_right = get_unqualified_type(points_to_right);
 986
 987                         if (is_type_void(points_to_left))
 988                                 return res;
 989
 990                         if (is_type_void(points_to_right)) {
 991                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 992                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 993                         }
 994
 995                         if (!types_compatible(points_to_left, points_to_right)) {
 996                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
 997                         }
 998
 999                         return res;
1000                 } else if (is_type_integer(type_right)) {
1001                         return ASSIGN_WARNING_POINTER_FROM_INT;
1002                 }
1003         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1004                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1005                                 && is_type_pointer(type_right))) {
1006                 return ASSIGN_SUCCESS;
1007         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1008                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1009                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1010                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1011                         return ASSIGN_SUCCESS;
1012                 }
1013         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1014                 return ASSIGN_WARNING_INT_FROM_POINTER;
1015         }
1016
1017         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1018                 return ASSIGN_SUCCESS;
1019
1020         return ASSIGN_ERROR_INCOMPATIBLE;
1021 }
1022
1023 static expression_t *parse_constant_expression(void)
1024 {
1025         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1026
1027         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1028                 errorf(&result->base.source_position,
1029                        "expression '%E' is not constant", result);
1030         }
1031
1032         return result;
1033 }
1034
1035 static expression_t *parse_assignment_expression(void)
1036 {
1037         return parse_subexpression(PREC_ASSIGNMENT);
1038 }
1039
1040 static void warn_string_concat(const source_position_t *pos)
1041 {
1042         warningf(WARN_TRADITIONAL, pos, "traditional C rejects string constant concatenation");
1043 }
1044
1045 static string_t parse_string_literals(void)
1046 {
1047         assert(token.kind == T_STRING_LITERAL);
1048         string_t result = token.string.string;
1049
1050         next_token();
1051
1052         while (token.kind == T_STRING_LITERAL) {
1053                 warn_string_concat(HERE);
1054                 result = concat_strings(&result, &token.string.string);
1055                 next_token();
1056         }
1057
1058         return result;
1059 }
1060
1061 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1062 {
1063         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1064         attribute->kind            = kind;
1065         attribute->source_position = *HERE;
1066         return attribute;
1067 }
1068
1069 /**
1070  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1071  *
1072  *  attribute:
1073  *    __attribute__ ( ( attribute-list ) )
1074  *
1075  *  attribute-list:
1076  *    attrib
1077  *    attribute_list , attrib
1078  *
1079  *  attrib:
1080  *    empty
1081  *    any-word
1082  *    any-word ( identifier )
1083  *    any-word ( identifier , nonempty-expr-list )
1084  *    any-word ( expr-list )
1085  *
1086  *  where the "identifier" must not be declared as a type, and
1087  *  "any-word" may be any identifier (including one declared as a
1088  *  type), a reserved word storage class specifier, type specifier or
1089  *  type qualifier.  ??? This still leaves out most reserved keywords
1090  *  (following the old parser), shouldn't we include them, and why not
1091  *  allow identifiers declared as types to start the arguments?
1092  *
1093  *  Matze: this all looks confusing and little systematic, so we're even less
1094  *  strict and parse any list of things which are identifiers or
1095  *  (assignment-)expressions.
1096  */
1097 static attribute_argument_t *parse_attribute_arguments(void)
1098 {
1099         attribute_argument_t  *first  = NULL;
1100         attribute_argument_t **anchor = &first;
1101         if (token.kind != ')') do {
1102                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1103
1104                 /* is it an identifier */
1105                 if (token.kind == T_IDENTIFIER
1106                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1107                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1108                         argument->v.symbol = token.base.symbol;
1109                         next_token();
1110                 } else {
1111                         /* must be an expression */
1112                         expression_t *expression = parse_assignment_expression();
1113
1114                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1115                         argument->v.expression = expression;
1116                 }
1117
1118                 /* append argument */
1119                 *anchor = argument;
1120                 anchor  = &argument->next;
1121         } while (next_if(','));
1122         expect(')');
1123         return first;
1124 }
1125
1126 static attribute_t *parse_attribute_asm(void)
1127 {
1128         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1129         eat(T_asm);
1130         expect('(');
1131         attribute->a.arguments = parse_attribute_arguments();
1132         return attribute;
1133 }
1134
1135 static attribute_t *parse_attribute_gnu_single(void)
1136 {
1137         /* parse "any-word" */
1138         symbol_t *const symbol = token.base.symbol;
1139         if (symbol == NULL) {
1140                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1141                 return NULL;
1142         }
1143
1144         attribute_kind_t  kind;
1145         char const *const name = symbol->string;
1146         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1147                 if (kind > ATTRIBUTE_GNU_LAST) {
1148                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1149                         /* TODO: we should still save the attribute in the list... */
1150                         kind = ATTRIBUTE_UNKNOWN;
1151                         break;
1152                 }
1153
1154                 const char *attribute_name = get_attribute_name(kind);
1155                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1156                         break;
1157         }
1158
1159         attribute_t *attribute = allocate_attribute_zero(kind);
1160         next_token();
1161
1162         /* parse arguments */
1163         if (next_if('('))
1164                 attribute->a.arguments = parse_attribute_arguments();
1165
1166         return attribute;
1167 }
1168
1169 static attribute_t *parse_attribute_gnu(void)
1170 {
1171         attribute_t  *first  = NULL;
1172         attribute_t **anchor = &first;
1173
1174         eat(T___attribute__);
1175         expect('(');
1176         expect('(');
1177
1178         add_anchor_token(')');
1179         add_anchor_token(',');
1180         if (token.kind != ')') do {
1181                 attribute_t *attribute = parse_attribute_gnu_single();
1182                 if (attribute) {
1183                         *anchor = attribute;
1184                         anchor  = &attribute->next;
1185                 }
1186         } while (next_if(','));
1187         rem_anchor_token(',');
1188         rem_anchor_token(')');
1189
1190         expect(')');
1191         expect(')');
1192         return first;
1193 }
1194
1195 /** Parse attributes. */
1196 static attribute_t *parse_attributes(attribute_t *first)
1197 {
1198         attribute_t **anchor = &first;
1199         for (;;) {
1200                 while (*anchor != NULL)
1201                         anchor = &(*anchor)->next;
1202
1203                 attribute_t *attribute;
1204                 switch (token.kind) {
1205                 case T___attribute__:
1206                         attribute = parse_attribute_gnu();
1207                         if (attribute == NULL)
1208                                 continue;
1209                         break;
1210
1211                 case T_asm:
1212                         attribute = parse_attribute_asm();
1213                         break;
1214
1215                 case T_cdecl:
1216                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1217                         eat(T_cdecl);
1218                         break;
1219
1220                 case T__fastcall:
1221                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1222                         eat(T__fastcall);
1223                         break;
1224
1225                 case T__forceinline:
1226                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1227                         eat(T__forceinline);
1228                         break;
1229
1230                 case T__stdcall:
1231                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1232                         eat(T__stdcall);
1233                         break;
1234
1235                 case T___thiscall:
1236                         /* TODO record modifier */
1237                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1238                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1239                         eat(T___thiscall);
1240                         break;
1241
1242                 default:
1243                         return first;
1244                 }
1245
1246                 *anchor = attribute;
1247                 anchor  = &attribute->next;
1248         }
1249 }
1250
1251 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1252
1253 static entity_t *determine_lhs_ent(expression_t *const expr,
1254                                    entity_t *lhs_ent)
1255 {
1256         switch (expr->kind) {
1257                 case EXPR_REFERENCE: {
1258                         entity_t *const entity = expr->reference.entity;
1259                         /* we should only find variables as lvalues... */
1260                         if (entity->base.kind != ENTITY_VARIABLE
1261                                         && entity->base.kind != ENTITY_PARAMETER)
1262                                 return NULL;
1263
1264                         return entity;
1265                 }
1266
1267                 case EXPR_ARRAY_ACCESS: {
1268                         expression_t *const ref = expr->array_access.array_ref;
1269                         entity_t     *      ent = NULL;
1270                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1271                                 ent     = determine_lhs_ent(ref, lhs_ent);
1272                                 lhs_ent = ent;
1273                         } else {
1274                                 mark_vars_read(ref, lhs_ent);
1275                         }
1276                         mark_vars_read(expr->array_access.index, lhs_ent);
1277                         return ent;
1278                 }
1279
1280                 case EXPR_SELECT: {
1281                         mark_vars_read(expr->select.compound, lhs_ent);
1282                         if (is_type_compound(skip_typeref(expr->base.type)))
1283                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1284                         return NULL;
1285                 }
1286
1287                 case EXPR_UNARY_DEREFERENCE: {
1288                         expression_t *const val = expr->unary.value;
1289                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1290                                 /* *&x is a NOP */
1291                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1292                         } else {
1293                                 mark_vars_read(val, NULL);
1294                                 return NULL;
1295                         }
1296                 }
1297
1298                 default:
1299                         mark_vars_read(expr, NULL);
1300                         return NULL;
1301         }
1302 }
1303
1304 #define ENT_ANY ((entity_t*)-1)
1305
1306 /**
1307  * Mark declarations, which are read.  This is used to detect variables, which
1308  * are never read.
1309  * Example:
1310  * x = x + 1;
1311  *   x is not marked as "read", because it is only read to calculate its own new
1312  *   value.
1313  *
1314  * x += y; y += x;
1315  *   x and y are not detected as "not read", because multiple variables are
1316  *   involved.
1317  */
1318 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1319 {
1320         switch (expr->kind) {
1321                 case EXPR_REFERENCE: {
1322                         entity_t *const entity = expr->reference.entity;
1323                         if (entity->kind != ENTITY_VARIABLE
1324                                         && entity->kind != ENTITY_PARAMETER)
1325                                 return;
1326
1327                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1328                                 entity->variable.read = true;
1329                         }
1330                         return;
1331                 }
1332
1333                 case EXPR_CALL:
1334                         // TODO respect pure/const
1335                         mark_vars_read(expr->call.function, NULL);
1336                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1337                                 mark_vars_read(arg->expression, NULL);
1338                         }
1339                         return;
1340
1341                 case EXPR_CONDITIONAL:
1342                         // TODO lhs_decl should depend on whether true/false have an effect
1343                         mark_vars_read(expr->conditional.condition, NULL);
1344                         if (expr->conditional.true_expression != NULL)
1345                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1346                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1347                         return;
1348
1349                 case EXPR_SELECT:
1350                         if (lhs_ent == ENT_ANY
1351                                         && !is_type_compound(skip_typeref(expr->base.type)))
1352                                 lhs_ent = NULL;
1353                         mark_vars_read(expr->select.compound, lhs_ent);
1354                         return;
1355
1356                 case EXPR_ARRAY_ACCESS: {
1357                         mark_vars_read(expr->array_access.index, lhs_ent);
1358                         expression_t *const ref = expr->array_access.array_ref;
1359                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1360                                 if (lhs_ent == ENT_ANY)
1361                                         lhs_ent = NULL;
1362                         }
1363                         mark_vars_read(ref, lhs_ent);
1364                         return;
1365                 }
1366
1367                 case EXPR_VA_ARG:
1368                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1369                         return;
1370
1371                 case EXPR_VA_COPY:
1372                         mark_vars_read(expr->va_copye.src, lhs_ent);
1373                         return;
1374
1375                 case EXPR_UNARY_CAST:
1376                         /* Special case: Use void cast to mark a variable as "read" */
1377                         if (is_type_void(skip_typeref(expr->base.type)))
1378                                 lhs_ent = NULL;
1379                         goto unary;
1380
1381
1382                 case EXPR_UNARY_THROW:
1383                         if (expr->unary.value == NULL)
1384                                 return;
1385                         /* FALLTHROUGH */
1386                 case EXPR_UNARY_DEREFERENCE:
1387                 case EXPR_UNARY_DELETE:
1388                 case EXPR_UNARY_DELETE_ARRAY:
1389                         if (lhs_ent == ENT_ANY)
1390                                 lhs_ent = NULL;
1391                         goto unary;
1392
1393                 case EXPR_UNARY_NEGATE:
1394                 case EXPR_UNARY_PLUS:
1395                 case EXPR_UNARY_BITWISE_NEGATE:
1396                 case EXPR_UNARY_NOT:
1397                 case EXPR_UNARY_TAKE_ADDRESS:
1398                 case EXPR_UNARY_POSTFIX_INCREMENT:
1399                 case EXPR_UNARY_POSTFIX_DECREMENT:
1400                 case EXPR_UNARY_PREFIX_INCREMENT:
1401                 case EXPR_UNARY_PREFIX_DECREMENT:
1402                 case EXPR_UNARY_ASSUME:
1403 unary:
1404                         mark_vars_read(expr->unary.value, lhs_ent);
1405                         return;
1406
1407                 case EXPR_BINARY_ADD:
1408                 case EXPR_BINARY_SUB:
1409                 case EXPR_BINARY_MUL:
1410                 case EXPR_BINARY_DIV:
1411                 case EXPR_BINARY_MOD:
1412                 case EXPR_BINARY_EQUAL:
1413                 case EXPR_BINARY_NOTEQUAL:
1414                 case EXPR_BINARY_LESS:
1415                 case EXPR_BINARY_LESSEQUAL:
1416                 case EXPR_BINARY_GREATER:
1417                 case EXPR_BINARY_GREATEREQUAL:
1418                 case EXPR_BINARY_BITWISE_AND:
1419                 case EXPR_BINARY_BITWISE_OR:
1420                 case EXPR_BINARY_BITWISE_XOR:
1421                 case EXPR_BINARY_LOGICAL_AND:
1422                 case EXPR_BINARY_LOGICAL_OR:
1423                 case EXPR_BINARY_SHIFTLEFT:
1424                 case EXPR_BINARY_SHIFTRIGHT:
1425                 case EXPR_BINARY_COMMA:
1426                 case EXPR_BINARY_ISGREATER:
1427                 case EXPR_BINARY_ISGREATEREQUAL:
1428                 case EXPR_BINARY_ISLESS:
1429                 case EXPR_BINARY_ISLESSEQUAL:
1430                 case EXPR_BINARY_ISLESSGREATER:
1431                 case EXPR_BINARY_ISUNORDERED:
1432                         mark_vars_read(expr->binary.left,  lhs_ent);
1433                         mark_vars_read(expr->binary.right, lhs_ent);
1434                         return;
1435
1436                 case EXPR_BINARY_ASSIGN:
1437                 case EXPR_BINARY_MUL_ASSIGN:
1438                 case EXPR_BINARY_DIV_ASSIGN:
1439                 case EXPR_BINARY_MOD_ASSIGN:
1440                 case EXPR_BINARY_ADD_ASSIGN:
1441                 case EXPR_BINARY_SUB_ASSIGN:
1442                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1443                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1444                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1445                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1446                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1447                         if (lhs_ent == ENT_ANY)
1448                                 lhs_ent = NULL;
1449                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1450                         mark_vars_read(expr->binary.right, lhs_ent);
1451                         return;
1452                 }
1453
1454                 case EXPR_VA_START:
1455                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1456                         return;
1457
1458                 case EXPR_LITERAL_CASES:
1459                 case EXPR_ERROR:
1460                 case EXPR_STRING_LITERAL:
1461                 case EXPR_WIDE_STRING_LITERAL:
1462                 case EXPR_COMPOUND_LITERAL: // TODO init?
1463                 case EXPR_SIZEOF:
1464                 case EXPR_CLASSIFY_TYPE:
1465                 case EXPR_ALIGNOF:
1466                 case EXPR_FUNCNAME:
1467                 case EXPR_BUILTIN_CONSTANT_P:
1468                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1469                 case EXPR_OFFSETOF:
1470                 case EXPR_STATEMENT: // TODO
1471                 case EXPR_LABEL_ADDRESS:
1472                 case EXPR_ENUM_CONSTANT:
1473                         return;
1474         }
1475
1476         panic("unhandled expression");
1477 }
1478
1479 static designator_t *parse_designation(void)
1480 {
1481         designator_t  *result = NULL;
1482         designator_t **anchor = &result;
1483
1484         for (;;) {
1485                 designator_t *designator;
1486                 switch (token.kind) {
1487                 case '[':
1488                         designator = allocate_ast_zero(sizeof(designator[0]));
1489                         designator->source_position = *HERE;
1490                         next_token();
1491                         add_anchor_token(']');
1492                         designator->array_index = parse_constant_expression();
1493                         rem_anchor_token(']');
1494                         expect(']');
1495                         break;
1496                 case '.':
1497                         designator = allocate_ast_zero(sizeof(designator[0]));
1498                         designator->source_position = *HERE;
1499                         next_token();
1500                         designator->symbol = expect_identifier("while parsing designator", NULL);
1501                         if (!designator->symbol)
1502                                 return NULL;
1503                         break;
1504                 default:
1505                         expect('=');
1506                         return result;
1507                 }
1508
1509                 assert(designator != NULL);
1510                 *anchor = designator;
1511                 anchor  = &designator->next;
1512         }
1513 }
1514
1515 static initializer_t *initializer_from_string(array_type_t *const type,
1516                                               const string_t *const string)
1517 {
1518         /* TODO: check len vs. size of array type */
1519         (void) type;
1520
1521         initializer_t *initializer = allocate_initializer_zero(INITIALIZER_STRING);
1522         initializer->string.string = *string;
1523
1524         return initializer;
1525 }
1526
1527 static initializer_t *initializer_from_wide_string(array_type_t *const type,
1528                                                    const string_t *const string)
1529 {
1530         /* TODO: check len vs. size of array type */
1531         (void) type;
1532
1533         initializer_t *const initializer =
1534                 allocate_initializer_zero(INITIALIZER_WIDE_STRING);
1535         initializer->wide_string.string = *string;
1536
1537         return initializer;
1538 }
1539
1540 /**
1541  * Build an initializer from a given expression.
1542  */
1543 static initializer_t *initializer_from_expression(type_t *orig_type,
1544                                                   expression_t *expression)
1545 {
1546         /* TODO check that expression is a constant expression */
1547
1548         /* §6.7.8.14/15 char array may be initialized by string literals */
1549         type_t *type           = skip_typeref(orig_type);
1550         type_t *expr_type_orig = expression->base.type;
1551         type_t *expr_type      = skip_typeref(expr_type_orig);
1552
1553         if (is_type_array(type) && expr_type->kind == TYPE_POINTER) {
1554                 array_type_t *const array_type   = &type->array;
1555                 type_t       *const element_type = skip_typeref(array_type->element_type);
1556
1557                 if (element_type->kind == TYPE_ATOMIC) {
1558                         atomic_type_kind_t akind = element_type->atomic.akind;
1559                         switch (expression->kind) {
1560                         case EXPR_STRING_LITERAL:
1561                                 if (akind == ATOMIC_TYPE_CHAR
1562                                                 || akind == ATOMIC_TYPE_SCHAR
1563                                                 || akind == ATOMIC_TYPE_UCHAR) {
1564                                         return initializer_from_string(array_type,
1565                                                         &expression->string_literal.value);
1566                                 }
1567                                 break;
1568
1569                         case EXPR_WIDE_STRING_LITERAL: {
1570                                 type_t *bare_wchar_type = skip_typeref(type_wchar_t);
1571                                 if (get_unqualified_type(element_type) == bare_wchar_type) {
1572                                         return initializer_from_wide_string(array_type,
1573                                                         &expression->string_literal.value);
1574                                 }
1575                                 break;
1576                         }
1577
1578                         default:
1579                                 break;
1580                         }
1581                 }
1582         }
1583
1584         assign_error_t error = semantic_assign(type, expression);
1585         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1586                 return NULL;
1587         report_assign_error(error, type, expression, "initializer",
1588                             &expression->base.source_position);
1589
1590         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1591         result->value.value = create_implicit_cast(expression, type);
1592
1593         return result;
1594 }
1595
1596 /**
1597  * Parses an scalar initializer.
1598  *
1599  * §6.7.8.11; eat {} without warning
1600  */
1601 static initializer_t *parse_scalar_initializer(type_t *type,
1602                                                bool must_be_constant)
1603 {
1604         /* there might be extra {} hierarchies */
1605         int braces = 0;
1606         if (token.kind == '{') {
1607                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1608                 do {
1609                         eat('{');
1610                         ++braces;
1611                 } while (token.kind == '{');
1612         }
1613
1614         expression_t *expression = parse_assignment_expression();
1615         mark_vars_read(expression, NULL);
1616         if (must_be_constant && !is_linker_constant(expression)) {
1617                 errorf(&expression->base.source_position,
1618                        "initialisation expression '%E' is not constant",
1619                        expression);
1620         }
1621
1622         initializer_t *initializer = initializer_from_expression(type, expression);
1623
1624         if (initializer == NULL) {
1625                 errorf(&expression->base.source_position,
1626                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1627                        expression, expression->base.type, type);
1628                 /* TODO */
1629                 return NULL;
1630         }
1631
1632         bool additional_warning_displayed = false;
1633         while (braces > 0) {
1634                 next_if(',');
1635                 if (token.kind != '}') {
1636                         if (!additional_warning_displayed) {
1637                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1638                                 additional_warning_displayed = true;
1639                         }
1640                 }
1641                 eat_block();
1642                 braces--;
1643         }
1644
1645         return initializer;
1646 }
1647
1648 /**
1649  * An entry in the type path.
1650  */
1651 typedef struct type_path_entry_t type_path_entry_t;
1652 struct type_path_entry_t {
1653         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1654         union {
1655                 size_t         index;          /**< For array types: the current index. */
1656                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1657         } v;
1658 };
1659
1660 /**
1661  * A type path expression a position inside compound or array types.
1662  */
1663 typedef struct type_path_t type_path_t;
1664 struct type_path_t {
1665         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1666         type_t            *top_type;     /**< type of the element the path points */
1667         size_t             max_index;    /**< largest index in outermost array */
1668 };
1669
1670 /**
1671  * Prints a type path for debugging.
1672  */
1673 static __attribute__((unused)) void debug_print_type_path(
1674                 const type_path_t *path)
1675 {
1676         size_t len = ARR_LEN(path->path);
1677
1678         for (size_t i = 0; i < len; ++i) {
1679                 const type_path_entry_t *entry = & path->path[i];
1680
1681                 type_t *type = skip_typeref(entry->type);
1682                 if (is_type_compound(type)) {
1683                         /* in gcc mode structs can have no members */
1684                         if (entry->v.compound_entry == NULL) {
1685                                 assert(i == len-1);
1686                                 continue;
1687                         }
1688                         fprintf(stderr, ".%s",
1689                                 entry->v.compound_entry->base.symbol->string);
1690                 } else if (is_type_array(type)) {
1691                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1692                 } else {
1693                         fprintf(stderr, "-INVALID-");
1694                 }
1695         }
1696         if (path->top_type != NULL) {
1697                 fprintf(stderr, "  (");
1698                 print_type(path->top_type);
1699                 fprintf(stderr, ")");
1700         }
1701 }
1702
1703 /**
1704  * Return the top type path entry, ie. in a path
1705  * (type).a.b returns the b.
1706  */
1707 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1708 {
1709         size_t len = ARR_LEN(path->path);
1710         assert(len > 0);
1711         return &path->path[len-1];
1712 }
1713
1714 /**
1715  * Enlarge the type path by an (empty) element.
1716  */
1717 static type_path_entry_t *append_to_type_path(type_path_t *path)
1718 {
1719         size_t len = ARR_LEN(path->path);
1720         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1721
1722         type_path_entry_t *result = & path->path[len];
1723         memset(result, 0, sizeof(result[0]));
1724         return result;
1725 }
1726
1727 /**
1728  * Descending into a sub-type. Enter the scope of the current top_type.
1729  */
1730 static void descend_into_subtype(type_path_t *path)
1731 {
1732         type_t *orig_top_type = path->top_type;
1733         type_t *top_type      = skip_typeref(orig_top_type);
1734
1735         type_path_entry_t *top = append_to_type_path(path);
1736         top->type              = top_type;
1737
1738         if (is_type_compound(top_type)) {
1739                 compound_t *const compound = top_type->compound.compound;
1740                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1741
1742                 if (entry != NULL) {
1743                         top->v.compound_entry = &entry->declaration;
1744                         path->top_type = entry->declaration.type;
1745                 } else {
1746                         path->top_type = NULL;
1747                 }
1748         } else if (is_type_array(top_type)) {
1749                 top->v.index   = 0;
1750                 path->top_type = top_type->array.element_type;
1751         } else {
1752                 assert(!is_type_valid(top_type));
1753         }
1754 }
1755
1756 /**
1757  * Pop an entry from the given type path, ie. returning from
1758  * (type).a.b to (type).a
1759  */
1760 static void ascend_from_subtype(type_path_t *path)
1761 {
1762         type_path_entry_t *top = get_type_path_top(path);
1763
1764         path->top_type = top->type;
1765
1766         size_t len = ARR_LEN(path->path);
1767         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1768 }
1769
1770 /**
1771  * Pop entries from the given type path until the given
1772  * path level is reached.
1773  */
1774 static void ascend_to(type_path_t *path, size_t top_path_level)
1775 {
1776         size_t len = ARR_LEN(path->path);
1777
1778         while (len > top_path_level) {
1779                 ascend_from_subtype(path);
1780                 len = ARR_LEN(path->path);
1781         }
1782 }
1783
1784 static bool walk_designator(type_path_t *path, const designator_t *designator,
1785                             bool used_in_offsetof)
1786 {
1787         for (; designator != NULL; designator = designator->next) {
1788                 type_path_entry_t *top       = get_type_path_top(path);
1789                 type_t            *orig_type = top->type;
1790
1791                 type_t *type = skip_typeref(orig_type);
1792
1793                 if (designator->symbol != NULL) {
1794                         symbol_t *symbol = designator->symbol;
1795                         if (!is_type_compound(type)) {
1796                                 if (is_type_valid(type)) {
1797                                         errorf(&designator->source_position,
1798                                                "'.%Y' designator used for non-compound type '%T'",
1799                                                symbol, orig_type);
1800                                 }
1801
1802                                 top->type             = type_error_type;
1803                                 top->v.compound_entry = NULL;
1804                                 orig_type             = type_error_type;
1805                         } else {
1806                                 compound_t *compound = type->compound.compound;
1807                                 entity_t   *iter     = compound->members.entities;
1808                                 for (; iter != NULL; iter = iter->base.next) {
1809                                         if (iter->base.symbol == symbol) {
1810                                                 break;
1811                                         }
1812                                 }
1813                                 if (iter == NULL) {
1814                                         errorf(&designator->source_position,
1815                                                "'%T' has no member named '%Y'", orig_type, symbol);
1816                                         return false;
1817                                 }
1818                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1819                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1820                                         errorf(&designator->source_position,
1821                                                    "offsetof designator '%Y' must not specify bitfield",
1822                                                    symbol);
1823                                         return false;
1824                                 }
1825
1826                                 top->type             = orig_type;
1827                                 top->v.compound_entry = &iter->declaration;
1828                                 orig_type             = iter->declaration.type;
1829                         }
1830                 } else {
1831                         expression_t *array_index = designator->array_index;
1832                         assert(designator->array_index != NULL);
1833
1834                         if (!is_type_array(type)) {
1835                                 if (is_type_valid(type)) {
1836                                         errorf(&designator->source_position,
1837                                                "[%E] designator used for non-array type '%T'",
1838                                                array_index, orig_type);
1839                                 }
1840                                 return false;
1841                         }
1842
1843                         long index = fold_constant_to_int(array_index);
1844                         if (!used_in_offsetof) {
1845                                 if (index < 0) {
1846                                         errorf(&designator->source_position,
1847                                                "array index [%E] must be positive", array_index);
1848                                 } else if (type->array.size_constant) {
1849                                         long array_size = type->array.size;
1850                                         if (index >= array_size) {
1851                                                 errorf(&designator->source_position,
1852                                                        "designator [%E] (%d) exceeds array size %d",
1853                                                        array_index, index, array_size);
1854                                         }
1855                                 }
1856                         }
1857
1858                         top->type    = orig_type;
1859                         top->v.index = (size_t) index;
1860                         orig_type    = type->array.element_type;
1861                 }
1862                 path->top_type = orig_type;
1863
1864                 if (designator->next != NULL) {
1865                         descend_into_subtype(path);
1866                 }
1867         }
1868         return true;
1869 }
1870
1871 static void advance_current_object(type_path_t *path, size_t top_path_level)
1872 {
1873         type_path_entry_t *top = get_type_path_top(path);
1874
1875         type_t *type = skip_typeref(top->type);
1876         if (is_type_union(type)) {
1877                 /* in unions only the first element is initialized */
1878                 top->v.compound_entry = NULL;
1879         } else if (is_type_struct(type)) {
1880                 declaration_t *entry = top->v.compound_entry;
1881
1882                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1883                 if (next_entity != NULL) {
1884                         assert(is_declaration(next_entity));
1885                         entry = &next_entity->declaration;
1886                 } else {
1887                         entry = NULL;
1888                 }
1889
1890                 top->v.compound_entry = entry;
1891                 if (entry != NULL) {
1892                         path->top_type = entry->type;
1893                         return;
1894                 }
1895         } else if (is_type_array(type)) {
1896                 assert(is_type_array(type));
1897
1898                 top->v.index++;
1899
1900                 if (!type->array.size_constant || top->v.index < type->array.size) {
1901                         return;
1902                 }
1903         } else {
1904                 assert(!is_type_valid(type));
1905                 return;
1906         }
1907
1908         /* we're past the last member of the current sub-aggregate, try if we
1909          * can ascend in the type hierarchy and continue with another subobject */
1910         size_t len = ARR_LEN(path->path);
1911
1912         if (len > top_path_level) {
1913                 ascend_from_subtype(path);
1914                 advance_current_object(path, top_path_level);
1915         } else {
1916                 path->top_type = NULL;
1917         }
1918 }
1919
1920 /**
1921  * skip any {...} blocks until a closing bracket is reached.
1922  */
1923 static void skip_initializers(void)
1924 {
1925         next_if('{');
1926
1927         while (token.kind != '}') {
1928                 if (token.kind == T_EOF)
1929                         return;
1930                 if (token.kind == '{') {
1931                         eat_block();
1932                         continue;
1933                 }
1934                 next_token();
1935         }
1936 }
1937
1938 static initializer_t *create_empty_initializer(void)
1939 {
1940         static initializer_t empty_initializer
1941                 = { .list = { { INITIALIZER_LIST }, 0 } };
1942         return &empty_initializer;
1943 }
1944
1945 /**
1946  * Parse a part of an initialiser for a struct or union,
1947  */
1948 static initializer_t *parse_sub_initializer(type_path_t *path,
1949                 type_t *outer_type, size_t top_path_level,
1950                 parse_initializer_env_t *env)
1951 {
1952         if (token.kind == '}') {
1953                 /* empty initializer */
1954                 return create_empty_initializer();
1955         }
1956
1957         type_t *orig_type = path->top_type;
1958         type_t *type      = NULL;
1959
1960         if (orig_type == NULL) {
1961                 /* We are initializing an empty compound. */
1962         } else {
1963                 type = skip_typeref(orig_type);
1964         }
1965
1966         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1967
1968         while (true) {
1969                 designator_t *designator = NULL;
1970                 if (token.kind == '.' || token.kind == '[') {
1971                         designator = parse_designation();
1972                         goto finish_designator;
1973                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1974                         /* GNU-style designator ("identifier: value") */
1975                         designator = allocate_ast_zero(sizeof(designator[0]));
1976                         designator->source_position = *HERE;
1977                         designator->symbol          = token.base.symbol;
1978                         eat(T_IDENTIFIER);
1979                         eat(':');
1980
1981 finish_designator:
1982                         /* reset path to toplevel, evaluate designator from there */
1983                         ascend_to(path, top_path_level);
1984                         if (!walk_designator(path, designator, false)) {
1985                                 /* can't continue after designation error */
1986                                 goto end_error;
1987                         }
1988
1989                         initializer_t *designator_initializer
1990                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
1991                         designator_initializer->designator.designator = designator;
1992                         ARR_APP1(initializer_t*, initializers, designator_initializer);
1993
1994                         orig_type = path->top_type;
1995                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
1996                 }
1997
1998                 initializer_t *sub;
1999
2000                 if (token.kind == '{') {
2001                         if (type != NULL && is_type_scalar(type)) {
2002                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2003                         } else {
2004                                 if (type == NULL) {
2005                                         if (env->entity != NULL) {
2006                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2007                                         } else {
2008                                                 errorf(HERE, "extra brace group at end of initializer");
2009                                         }
2010                                         eat('{');
2011                                 } else {
2012                                         eat('{');
2013                                         descend_into_subtype(path);
2014                                 }
2015
2016                                 add_anchor_token('}');
2017                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2018                                                             env);
2019                                 rem_anchor_token('}');
2020
2021                                 expect('}');
2022
2023                                 if (!type)
2024                                         goto error_parse_next;
2025
2026                                 ascend_from_subtype(path);
2027                         }
2028                 } else {
2029                         /* must be an expression */
2030                         expression_t *expression = parse_assignment_expression();
2031                         mark_vars_read(expression, NULL);
2032
2033                         if (env->must_be_constant && !is_linker_constant(expression)) {
2034                                 errorf(&expression->base.source_position,
2035                                        "Initialisation expression '%E' is not constant",
2036                                        expression);
2037                         }
2038
2039                         if (type == NULL) {
2040                                 /* we are already outside, ... */
2041                                 if (outer_type == NULL)
2042                                         goto error_parse_next;
2043                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2044                                 if (is_type_compound(outer_type_skip) &&
2045                                                 !outer_type_skip->compound.compound->complete) {
2046                                         goto error_parse_next;
2047                                 }
2048
2049                                 source_position_t const* const pos = &expression->base.source_position;
2050                                 if (env->entity != NULL) {
2051                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2052                                 } else {
2053                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2054                                 }
2055                                 goto error_parse_next;
2056                         }
2057
2058                         /* handle { "string" } special case */
2059                         if ((expression->kind == EXPR_STRING_LITERAL
2060                                         || expression->kind == EXPR_WIDE_STRING_LITERAL)
2061                                         && outer_type != NULL) {
2062                                 sub = initializer_from_expression(outer_type, expression);
2063                                 if (sub != NULL) {
2064                                         next_if(',');
2065                                         if (token.kind != '}') {
2066                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", orig_type);
2067                                         }
2068                                         /* TODO: eat , ... */
2069                                         return sub;
2070                                 }
2071                         }
2072
2073                         /* descend into subtypes until expression matches type */
2074                         while (true) {
2075                                 orig_type = path->top_type;
2076                                 type      = skip_typeref(orig_type);
2077
2078                                 sub = initializer_from_expression(orig_type, expression);
2079                                 if (sub != NULL) {
2080                                         break;
2081                                 }
2082                                 if (!is_type_valid(type)) {
2083                                         goto end_error;
2084                                 }
2085                                 if (is_type_scalar(type)) {
2086                                         errorf(&expression->base.source_position,
2087                                                         "expression '%E' doesn't match expected type '%T'",
2088                                                         expression, orig_type);
2089                                         goto end_error;
2090                                 }
2091
2092                                 descend_into_subtype(path);
2093                         }
2094                 }
2095
2096                 /* update largest index of top array */
2097                 const type_path_entry_t *first      = &path->path[0];
2098                 type_t                  *first_type = first->type;
2099                 first_type                          = skip_typeref(first_type);
2100                 if (is_type_array(first_type)) {
2101                         size_t index = first->v.index;
2102                         if (index > path->max_index)
2103                                 path->max_index = index;
2104                 }
2105
2106                 /* append to initializers list */
2107                 ARR_APP1(initializer_t*, initializers, sub);
2108
2109 error_parse_next:
2110                 if (token.kind == '}') {
2111                         break;
2112                 }
2113                 add_anchor_token('}');
2114                 expect(',');
2115                 rem_anchor_token('}');
2116                 if (token.kind == '}') {
2117                         break;
2118                 }
2119
2120                 if (type != NULL) {
2121                         /* advance to the next declaration if we are not at the end */
2122                         advance_current_object(path, top_path_level);
2123                         orig_type = path->top_type;
2124                         if (orig_type != NULL)
2125                                 type = skip_typeref(orig_type);
2126                         else
2127                                 type = NULL;
2128                 }
2129         }
2130
2131         size_t len  = ARR_LEN(initializers);
2132         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2133         initializer_t *result = allocate_ast_zero(size);
2134         result->kind          = INITIALIZER_LIST;
2135         result->list.len      = len;
2136         memcpy(&result->list.initializers, initializers,
2137                len * sizeof(initializers[0]));
2138
2139         DEL_ARR_F(initializers);
2140         ascend_to(path, top_path_level+1);
2141
2142         return result;
2143
2144 end_error:
2145         skip_initializers();
2146         DEL_ARR_F(initializers);
2147         ascend_to(path, top_path_level+1);
2148         return NULL;
2149 }
2150
2151 static expression_t *make_size_literal(size_t value)
2152 {
2153         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2154         literal->base.type    = type_size_t;
2155
2156         char buf[128];
2157         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2158         literal->literal.value = make_string(buf);
2159
2160         return literal;
2161 }
2162
2163 /**
2164  * Parses an initializer. Parsers either a compound literal
2165  * (env->declaration == NULL) or an initializer of a declaration.
2166  */
2167 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2168 {
2169         type_t        *type      = skip_typeref(env->type);
2170         size_t         max_index = 0;
2171         initializer_t *result;
2172
2173         if (is_type_scalar(type)) {
2174                 result = parse_scalar_initializer(type, env->must_be_constant);
2175         } else if (token.kind == '{') {
2176                 eat('{');
2177
2178                 type_path_t path;
2179                 memset(&path, 0, sizeof(path));
2180                 path.top_type = env->type;
2181                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2182
2183                 descend_into_subtype(&path);
2184
2185                 add_anchor_token('}');
2186                 result = parse_sub_initializer(&path, env->type, 1, env);
2187                 rem_anchor_token('}');
2188
2189                 max_index = path.max_index;
2190                 DEL_ARR_F(path.path);
2191
2192                 expect('}');
2193         } else {
2194                 /* parse_scalar_initializer() also works in this case: we simply
2195                  * have an expression without {} around it */
2196                 result = parse_scalar_initializer(type, env->must_be_constant);
2197         }
2198
2199         /* §6.7.8:22 array initializers for arrays with unknown size determine
2200          * the array type size */
2201         if (is_type_array(type) && type->array.size_expression == NULL
2202                         && result != NULL) {
2203                 size_t size;
2204                 switch (result->kind) {
2205                 case INITIALIZER_LIST:
2206                         assert(max_index != 0xdeadbeaf);
2207                         size = max_index + 1;
2208                         break;
2209
2210                 case INITIALIZER_STRING:
2211                         size = result->string.string.size;
2212                         break;
2213
2214                 case INITIALIZER_WIDE_STRING:
2215                         size = result->wide_string.string.size;
2216                         break;
2217
2218                 case INITIALIZER_DESIGNATOR:
2219                 case INITIALIZER_VALUE:
2220                         /* can happen for parse errors */
2221                         size = 0;
2222                         break;
2223
2224                 default:
2225                         internal_errorf(HERE, "invalid initializer type");
2226                 }
2227
2228                 type_t *new_type = duplicate_type(type);
2229
2230                 new_type->array.size_expression   = make_size_literal(size);
2231                 new_type->array.size_constant     = true;
2232                 new_type->array.has_implicit_size = true;
2233                 new_type->array.size              = size;
2234                 env->type = new_type;
2235         }
2236
2237         return result;
2238 }
2239
2240 static void append_entity(scope_t *scope, entity_t *entity)
2241 {
2242         if (scope->last_entity != NULL) {
2243                 scope->last_entity->base.next = entity;
2244         } else {
2245                 scope->entities = entity;
2246         }
2247         entity->base.parent_entity = current_entity;
2248         scope->last_entity         = entity;
2249 }
2250
2251
2252 static compound_t *parse_compound_type_specifier(bool is_struct)
2253 {
2254         source_position_t const pos = *HERE;
2255         eat(is_struct ? T_struct : T_union);
2256
2257         symbol_t    *symbol     = NULL;
2258         entity_t    *entity     = NULL;
2259         attribute_t *attributes = NULL;
2260
2261         if (token.kind == T___attribute__) {
2262                 attributes = parse_attributes(NULL);
2263         }
2264
2265         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2266         if (token.kind == T_IDENTIFIER) {
2267                 /* the compound has a name, check if we have seen it already */
2268                 symbol = token.base.symbol;
2269                 entity = get_tag(symbol, kind);
2270                 next_token();
2271
2272                 if (entity != NULL) {
2273                         if (entity->base.parent_scope != current_scope &&
2274                             (token.kind == '{' || token.kind == ';')) {
2275                                 /* we're in an inner scope and have a definition. Shadow
2276                                  * existing definition in outer scope */
2277                                 entity = NULL;
2278                         } else if (entity->compound.complete && token.kind == '{') {
2279                                 source_position_t const *const ppos = &entity->base.source_position;
2280                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2281                                 /* clear members in the hope to avoid further errors */
2282                                 entity->compound.members.entities = NULL;
2283                         }
2284                 }
2285         } else if (token.kind != '{') {
2286                 char const *const msg =
2287                         is_struct ? "while parsing struct type specifier" :
2288                                     "while parsing union type specifier";
2289                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2290
2291                 return NULL;
2292         }
2293
2294         if (entity == NULL) {
2295                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2296                 entity->compound.alignment = 1;
2297                 entity->base.parent_scope  = current_scope;
2298                 if (symbol != NULL) {
2299                         environment_push(entity);
2300                 }
2301                 append_entity(current_scope, entity);
2302         }
2303
2304         if (token.kind == '{') {
2305                 parse_compound_type_entries(&entity->compound);
2306
2307                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2308                 if (symbol == NULL) {
2309                         assert(anonymous_entity == NULL);
2310                         anonymous_entity = entity;
2311                 }
2312         }
2313
2314         if (attributes != NULL) {
2315                 handle_entity_attributes(attributes, entity);
2316         }
2317
2318         return &entity->compound;
2319 }
2320
2321 static void parse_enum_entries(type_t *const enum_type)
2322 {
2323         eat('{');
2324
2325         if (token.kind == '}') {
2326                 errorf(HERE, "empty enum not allowed");
2327                 next_token();
2328                 return;
2329         }
2330
2331         add_anchor_token('}');
2332         add_anchor_token(',');
2333         do {
2334                 add_anchor_token('=');
2335                 source_position_t pos;
2336                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2337                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2338                 entity->enum_value.enum_type = enum_type;
2339                 rem_anchor_token('=');
2340
2341                 if (next_if('=')) {
2342                         expression_t *value = parse_constant_expression();
2343
2344                         value = create_implicit_cast(value, enum_type);
2345                         entity->enum_value.value = value;
2346
2347                         /* TODO semantic */
2348                 }
2349
2350                 record_entity(entity, false);
2351         } while (next_if(',') && token.kind != '}');
2352         rem_anchor_token(',');
2353         rem_anchor_token('}');
2354
2355         expect('}');
2356 }
2357
2358 static type_t *parse_enum_specifier(void)
2359 {
2360         source_position_t const pos = *HERE;
2361         entity_t               *entity;
2362         symbol_t               *symbol;
2363
2364         eat(T_enum);
2365         switch (token.kind) {
2366                 case T_IDENTIFIER:
2367                         symbol = token.base.symbol;
2368                         entity = get_tag(symbol, ENTITY_ENUM);
2369                         next_token();
2370
2371                         if (entity != NULL) {
2372                                 if (entity->base.parent_scope != current_scope &&
2373                                                 (token.kind == '{' || token.kind == ';')) {
2374                                         /* we're in an inner scope and have a definition. Shadow
2375                                          * existing definition in outer scope */
2376                                         entity = NULL;
2377                                 } else if (entity->enume.complete && token.kind == '{') {
2378                                         source_position_t const *const ppos = &entity->base.source_position;
2379                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2380                                 }
2381                         }
2382                         break;
2383
2384                 case '{':
2385                         entity = NULL;
2386                         symbol = NULL;
2387                         break;
2388
2389                 default:
2390                         parse_error_expected("while parsing enum type specifier",
2391                                         T_IDENTIFIER, '{', NULL);
2392                         return NULL;
2393         }
2394
2395         if (entity == NULL) {
2396                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2397                 entity->base.parent_scope = current_scope;
2398         }
2399
2400         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2401         type->enumt.enume      = &entity->enume;
2402         type->enumt.base.akind = ATOMIC_TYPE_INT;
2403
2404         if (token.kind == '{') {
2405                 if (symbol != NULL) {
2406                         environment_push(entity);
2407                 }
2408                 append_entity(current_scope, entity);
2409                 entity->enume.complete = true;
2410
2411                 parse_enum_entries(type);
2412                 parse_attributes(NULL);
2413
2414                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2415                 if (symbol == NULL) {
2416                         assert(anonymous_entity == NULL);
2417                         anonymous_entity = entity;
2418                 }
2419         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2420                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2421         }
2422
2423         return type;
2424 }
2425
2426 /**
2427  * if a symbol is a typedef to another type, return true
2428  */
2429 static bool is_typedef_symbol(symbol_t *symbol)
2430 {
2431         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2432         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2433 }
2434
2435 static type_t *parse_typeof(void)
2436 {
2437         eat(T___typeof__);
2438
2439         type_t *type;
2440
2441         expect('(');
2442         add_anchor_token(')');
2443
2444         expression_t *expression  = NULL;
2445
2446         switch (token.kind) {
2447         case T_IDENTIFIER:
2448                 if (is_typedef_symbol(token.base.symbol)) {
2449         DECLARATION_START
2450                         type = parse_typename();
2451                 } else {
2452         default:
2453                         expression = parse_expression();
2454                         type       = revert_automatic_type_conversion(expression);
2455                 }
2456                 break;
2457         }
2458
2459         rem_anchor_token(')');
2460         expect(')');
2461
2462         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2463         typeof_type->typeoft.expression  = expression;
2464         typeof_type->typeoft.typeof_type = type;
2465
2466         return typeof_type;
2467 }
2468
2469 typedef enum specifiers_t {
2470         SPECIFIER_SIGNED    = 1 << 0,
2471         SPECIFIER_UNSIGNED  = 1 << 1,
2472         SPECIFIER_LONG      = 1 << 2,
2473         SPECIFIER_INT       = 1 << 3,
2474         SPECIFIER_DOUBLE    = 1 << 4,
2475         SPECIFIER_CHAR      = 1 << 5,
2476         SPECIFIER_WCHAR_T   = 1 << 6,
2477         SPECIFIER_SHORT     = 1 << 7,
2478         SPECIFIER_LONG_LONG = 1 << 8,
2479         SPECIFIER_FLOAT     = 1 << 9,
2480         SPECIFIER_BOOL      = 1 << 10,
2481         SPECIFIER_VOID      = 1 << 11,
2482         SPECIFIER_INT8      = 1 << 12,
2483         SPECIFIER_INT16     = 1 << 13,
2484         SPECIFIER_INT32     = 1 << 14,
2485         SPECIFIER_INT64     = 1 << 15,
2486         SPECIFIER_INT128    = 1 << 16,
2487         SPECIFIER_COMPLEX   = 1 << 17,
2488         SPECIFIER_IMAGINARY = 1 << 18,
2489 } specifiers_t;
2490
2491 static type_t *get_typedef_type(symbol_t *symbol)
2492 {
2493         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2494         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2495                 return NULL;
2496
2497         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2498         type->typedeft.typedefe = &entity->typedefe;
2499
2500         return type;
2501 }
2502
2503 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2504 {
2505         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2506
2507         expect('(');
2508
2509         add_anchor_token(')');
2510         add_anchor_token(',');
2511         do {
2512                 add_anchor_token('=');
2513                 source_position_t pos;
2514                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2515                 rem_anchor_token('=');
2516
2517                 symbol_t **prop = NULL;
2518                 if (prop_sym) {
2519                         if (streq(prop_sym->string, "put")) {
2520                                 prop = &property->put_symbol;
2521                         } else if (streq(prop_sym->string, "get")) {
2522                                 prop = &property->get_symbol;
2523                         } else {
2524                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2525                         }
2526                 }
2527
2528                 add_anchor_token(T_IDENTIFIER);
2529                 expect('=');
2530                 rem_anchor_token(T_IDENTIFIER);
2531
2532                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2533                 if (prop != NULL)
2534                         *prop = sym ? sym : sym_anonymous;
2535         } while (next_if(','));
2536         rem_anchor_token(',');
2537         rem_anchor_token(')');
2538
2539         attribute->a.property = property;
2540
2541         expect(')');
2542         return attribute;
2543 }
2544
2545 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2546 {
2547         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2548         if (next_if(T_restrict)) {
2549                 kind = ATTRIBUTE_MS_RESTRICT;
2550         } else if (token.kind == T_IDENTIFIER) {
2551                 char const *const name = token.base.symbol->string;
2552                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2553                      ++k) {
2554                         const char *attribute_name = get_attribute_name(k);
2555                         if (attribute_name != NULL && streq(attribute_name, name)) {
2556                                 kind = k;
2557                                 break;
2558                         }
2559                 }
2560
2561                 if (kind == ATTRIBUTE_UNKNOWN) {
2562                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2563                 }
2564         } else {
2565                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2566                 return NULL;
2567         }
2568
2569         attribute_t *attribute = allocate_attribute_zero(kind);
2570         eat(T_IDENTIFIER);
2571
2572         if (kind == ATTRIBUTE_MS_PROPERTY) {
2573                 return parse_attribute_ms_property(attribute);
2574         }
2575
2576         /* parse arguments */
2577         if (next_if('('))
2578                 attribute->a.arguments = parse_attribute_arguments();
2579
2580         return attribute;
2581 }
2582
2583 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2584 {
2585         eat(T__declspec);
2586
2587         expect('(');
2588         if (token.kind != ')') {
2589                 add_anchor_token(')');
2590
2591                 attribute_t **anchor = &first;
2592                 do {
2593                         while (*anchor != NULL)
2594                                 anchor = &(*anchor)->next;
2595
2596                         attribute_t *attribute
2597                                 = parse_microsoft_extended_decl_modifier_single();
2598                         if (attribute == NULL)
2599                                 break;
2600
2601                         *anchor = attribute;
2602                         anchor  = &attribute->next;
2603                 } while (next_if(','));
2604
2605                 rem_anchor_token(')');
2606         }
2607         expect(')');
2608         return first;
2609 }
2610
2611 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2612 {
2613         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2614         if (is_declaration(entity)) {
2615                 entity->declaration.type     = type_error_type;
2616                 entity->declaration.implicit = true;
2617         } else if (kind == ENTITY_TYPEDEF) {
2618                 entity->typedefe.type    = type_error_type;
2619                 entity->typedefe.builtin = true;
2620         }
2621         if (kind != ENTITY_COMPOUND_MEMBER)
2622                 record_entity(entity, false);
2623         return entity;
2624 }
2625
2626 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2627 {
2628         type_t            *type            = NULL;
2629         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2630         unsigned           type_specifiers = 0;
2631         bool               newtype         = false;
2632         bool               saw_error       = false;
2633
2634         memset(specifiers, 0, sizeof(*specifiers));
2635         specifiers->source_position = *HERE;
2636
2637         while (true) {
2638                 specifiers->attributes = parse_attributes(specifiers->attributes);
2639
2640                 switch (token.kind) {
2641                 /* storage class */
2642 #define MATCH_STORAGE_CLASS(token, class)                                  \
2643                 case token:                                                        \
2644                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2645                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2646                         }                                                              \
2647                         specifiers->storage_class = class;                             \
2648                         if (specifiers->thread_local)                                  \
2649                                 goto check_thread_storage_class;                           \
2650                         next_token();                                                  \
2651                         break;
2652
2653                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2654                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2655                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2656                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2657                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2658
2659                 case T__declspec:
2660                         specifiers->attributes
2661                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2662                         break;
2663
2664                 case T___thread:
2665                         if (specifiers->thread_local) {
2666                                 errorf(HERE, "duplicate '__thread'");
2667                         } else {
2668                                 specifiers->thread_local = true;
2669 check_thread_storage_class:
2670                                 switch (specifiers->storage_class) {
2671                                         case STORAGE_CLASS_EXTERN:
2672                                         case STORAGE_CLASS_NONE:
2673                                         case STORAGE_CLASS_STATIC:
2674                                                 break;
2675
2676                                                 char const* wrong;
2677                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2678                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2679                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2680 wrong_thread_storage_class:
2681                                                 errorf(HERE, "'__thread' used with '%s'", wrong);
2682                                                 break;
2683                                 }
2684                         }
2685                         next_token();
2686                         break;
2687
2688                 /* type qualifiers */
2689 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2690                 case token:                                                     \
2691                         qualifiers |= qualifier;                                    \
2692                         next_token();                                               \
2693                         break
2694
2695                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2696                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2697                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2698                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2699                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2700                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2701                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2702                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2703
2704                 /* type specifiers */
2705 #define MATCH_SPECIFIER(token, specifier, name)                         \
2706                 case token:                                                     \
2707                         if (type_specifiers & specifier) {                           \
2708                                 errorf(HERE, "multiple " name " type specifiers given"); \
2709                         } else {                                                    \
2710                                 type_specifiers |= specifier;                           \
2711                         }                                                           \
2712                         next_token();                                               \
2713                         break
2714
2715                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2716                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2717                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2718                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2719                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2720                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2721                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2722                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2723                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2724                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2725                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2726                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2727                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2728                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2729                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2730                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2731                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2732                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2733
2734                 case T_inline:
2735                         next_token();
2736                         specifiers->is_inline = true;
2737                         break;
2738
2739 #if 0
2740                 case T__forceinline:
2741                         next_token();
2742                         specifiers->modifiers |= DM_FORCEINLINE;
2743                         break;
2744 #endif
2745
2746                 case T_long:
2747                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2748                                 errorf(HERE, "too many long type specifiers given");
2749                         } else if (type_specifiers & SPECIFIER_LONG) {
2750                                 type_specifiers |= SPECIFIER_LONG_LONG;
2751                         } else {
2752                                 type_specifiers |= SPECIFIER_LONG;
2753                         }
2754                         next_token();
2755                         break;
2756
2757 #define CHECK_DOUBLE_TYPE() \
2758         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2759
2760                 case T_struct:
2761                         CHECK_DOUBLE_TYPE();
2762                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2763
2764                         type->compound.compound = parse_compound_type_specifier(true);
2765                         break;
2766                 case T_union:
2767                         CHECK_DOUBLE_TYPE();
2768                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2769                         type->compound.compound = parse_compound_type_specifier(false);
2770                         break;
2771                 case T_enum:
2772                         CHECK_DOUBLE_TYPE();
2773                         type = parse_enum_specifier();
2774                         break;
2775                 case T___typeof__:
2776                         CHECK_DOUBLE_TYPE();
2777                         type = parse_typeof();
2778                         break;
2779                 case T___builtin_va_list:
2780                         CHECK_DOUBLE_TYPE();
2781                         type = duplicate_type(type_valist);
2782                         next_token();
2783                         break;
2784
2785                 case T_IDENTIFIER: {
2786                         /* only parse identifier if we haven't found a type yet */
2787                         if (type != NULL || type_specifiers != 0) {
2788                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2789                                  * declaration, so it doesn't generate errors about expecting '(' or
2790                                  * '{' later on. */
2791                                 switch (look_ahead(1)->kind) {
2792                                         STORAGE_CLASSES
2793                                         TYPE_SPECIFIERS
2794                                         case T_const:
2795                                         case T_restrict:
2796                                         case T_volatile:
2797                                         case T_inline:
2798                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2799                                         case T_IDENTIFIER:
2800                                         case '&':
2801                                         case '*':
2802                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2803                                                 next_token();
2804                                                 continue;
2805
2806                                         default:
2807                                                 goto finish_specifiers;
2808                                 }
2809                         }
2810
2811                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2812                         if (typedef_type == NULL) {
2813                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2814                                  * declaration, so it doesn't generate 'implicit int' followed by more
2815                                  * errors later on. */
2816                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2817                                 switch (la1_type) {
2818                                         DECLARATION_START
2819                                         case T_IDENTIFIER:
2820                                         case '&':
2821                                         case '*': {
2822                                                 errorf(HERE, "%K does not name a type", &token);
2823
2824                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2825
2826                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2827                                                 type->typedeft.typedefe = &entity->typedefe;
2828
2829                                                 next_token();
2830                                                 saw_error = true;
2831                                                 continue;
2832                                         }
2833
2834                                         default:
2835                                                 goto finish_specifiers;
2836                                 }
2837                         }
2838
2839                         next_token();
2840                         type = typedef_type;
2841                         break;
2842                 }
2843
2844                 /* function specifier */
2845                 default:
2846                         goto finish_specifiers;
2847                 }
2848         }
2849
2850 finish_specifiers:
2851         specifiers->attributes = parse_attributes(specifiers->attributes);
2852
2853         if (type == NULL || (saw_error && type_specifiers != 0)) {
2854                 atomic_type_kind_t atomic_type;
2855
2856                 /* match valid basic types */
2857                 switch (type_specifiers) {
2858                 case SPECIFIER_VOID:
2859                         atomic_type = ATOMIC_TYPE_VOID;
2860                         break;
2861                 case SPECIFIER_WCHAR_T:
2862                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2863                         break;
2864                 case SPECIFIER_CHAR:
2865                         atomic_type = ATOMIC_TYPE_CHAR;
2866                         break;
2867                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2868                         atomic_type = ATOMIC_TYPE_SCHAR;
2869                         break;
2870                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2871                         atomic_type = ATOMIC_TYPE_UCHAR;
2872                         break;
2873                 case SPECIFIER_SHORT:
2874                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2875                 case SPECIFIER_SHORT | SPECIFIER_INT:
2876                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2877                         atomic_type = ATOMIC_TYPE_SHORT;
2878                         break;
2879                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2880                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2881                         atomic_type = ATOMIC_TYPE_USHORT;
2882                         break;
2883                 case SPECIFIER_INT:
2884                 case SPECIFIER_SIGNED:
2885                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2886                         atomic_type = ATOMIC_TYPE_INT;
2887                         break;
2888                 case SPECIFIER_UNSIGNED:
2889                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2890                         atomic_type = ATOMIC_TYPE_UINT;
2891                         break;
2892                 case SPECIFIER_LONG:
2893                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2894                 case SPECIFIER_LONG | SPECIFIER_INT:
2895                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2896                         atomic_type = ATOMIC_TYPE_LONG;
2897                         break;
2898                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2899                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2900                         atomic_type = ATOMIC_TYPE_ULONG;
2901                         break;
2902
2903                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2904                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2905                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2906                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2907                         | SPECIFIER_INT:
2908                         atomic_type = ATOMIC_TYPE_LONGLONG;
2909                         goto warn_about_long_long;
2910
2911                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2912                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2913                         | SPECIFIER_INT:
2914                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2915 warn_about_long_long:
2916                         warningf(WARN_LONG_LONG, &specifiers->source_position, "ISO C90 does not support 'long long'");
2917                         break;
2918
2919                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2920                         atomic_type = unsigned_int8_type_kind;
2921                         break;
2922
2923                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2924                         atomic_type = unsigned_int16_type_kind;
2925                         break;
2926
2927                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2928                         atomic_type = unsigned_int32_type_kind;
2929                         break;
2930
2931                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2932                         atomic_type = unsigned_int64_type_kind;
2933                         break;
2934
2935                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2936                         atomic_type = unsigned_int128_type_kind;
2937                         break;
2938
2939                 case SPECIFIER_INT8:
2940                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2941                         atomic_type = int8_type_kind;
2942                         break;
2943
2944                 case SPECIFIER_INT16:
2945                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2946                         atomic_type = int16_type_kind;
2947                         break;
2948
2949                 case SPECIFIER_INT32:
2950                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2951                         atomic_type = int32_type_kind;
2952                         break;
2953
2954                 case SPECIFIER_INT64:
2955                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2956                         atomic_type = int64_type_kind;
2957                         break;
2958
2959                 case SPECIFIER_INT128:
2960                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2961                         atomic_type = int128_type_kind;
2962                         break;
2963
2964                 case SPECIFIER_FLOAT:
2965                         atomic_type = ATOMIC_TYPE_FLOAT;
2966                         break;
2967                 case SPECIFIER_DOUBLE:
2968                         atomic_type = ATOMIC_TYPE_DOUBLE;
2969                         break;
2970                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2971                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2972                         break;
2973                 case SPECIFIER_BOOL:
2974                         atomic_type = ATOMIC_TYPE_BOOL;
2975                         break;
2976                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2977                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2978                         atomic_type = ATOMIC_TYPE_FLOAT;
2979                         break;
2980                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2981                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2982                         atomic_type = ATOMIC_TYPE_DOUBLE;
2983                         break;
2984                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2985                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2986                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2987                         break;
2988                 default: {
2989                         /* invalid specifier combination, give an error message */
2990                         source_position_t const* const pos = &specifiers->source_position;
2991                         if (type_specifiers == 0) {
2992                                 if (!saw_error) {
2993                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
2994                                         if (!(c_mode & _CXX) && !strict_mode) {
2995                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
2996                                                 atomic_type = ATOMIC_TYPE_INT;
2997                                                 break;
2998                                         } else {
2999                                                 errorf(pos, "no type specifiers given in declaration");
3000                                         }
3001                                 }
3002                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3003                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3004                                 errorf(pos, "signed and unsigned specifiers given");
3005                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3006                                 errorf(pos, "only integer types can be signed or unsigned");
3007                         } else {
3008                                 errorf(pos, "multiple datatypes in declaration");
3009                         }
3010                         goto end_error;
3011                 }
3012                 }
3013
3014                 if (type_specifiers & SPECIFIER_COMPLEX) {
3015                         type = allocate_type_zero(TYPE_COMPLEX);
3016                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3017                         type = allocate_type_zero(TYPE_IMAGINARY);
3018                 } else {
3019                         type = allocate_type_zero(TYPE_ATOMIC);
3020                 }
3021                 type->atomic.akind = atomic_type;
3022                 newtype = true;
3023         } else if (type_specifiers != 0) {
3024                 errorf(&specifiers->source_position, "multiple datatypes in declaration");
3025         }
3026
3027         /* FIXME: check type qualifiers here */
3028         type->base.qualifiers = qualifiers;
3029
3030         if (newtype) {
3031                 type = identify_new_type(type);
3032         } else {
3033                 type = typehash_insert(type);
3034         }
3035
3036         if (specifiers->attributes != NULL)
3037                 type = handle_type_attributes(specifiers->attributes, type);
3038         specifiers->type = type;
3039         return;
3040
3041 end_error:
3042         specifiers->type = type_error_type;
3043 }
3044
3045 static type_qualifiers_t parse_type_qualifiers(void)
3046 {
3047         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3048
3049         while (true) {
3050                 switch (token.kind) {
3051                 /* type qualifiers */
3052                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3053                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3054                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3055                 /* microsoft extended type modifiers */
3056                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3057                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3058                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3059                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3060                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3061
3062                 default:
3063                         return qualifiers;
3064                 }
3065         }
3066 }
3067
3068 /**
3069  * Parses an K&R identifier list
3070  */
3071 static void parse_identifier_list(scope_t *scope)
3072 {
3073         assert(token.kind == T_IDENTIFIER);
3074         do {
3075                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3076                 /* a K&R parameter has no type, yet */
3077                 next_token();
3078
3079                 if (scope != NULL)
3080                         append_entity(scope, entity);
3081         } while (next_if(',') && token.kind == T_IDENTIFIER);
3082 }
3083
3084 static entity_t *parse_parameter(void)
3085 {
3086         declaration_specifiers_t specifiers;
3087         parse_declaration_specifiers(&specifiers);
3088
3089         entity_t *entity = parse_declarator(&specifiers,
3090                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3091         anonymous_entity = NULL;
3092         return entity;
3093 }
3094
3095 static void semantic_parameter_incomplete(const entity_t *entity)
3096 {
3097         assert(entity->kind == ENTITY_PARAMETER);
3098
3099         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3100          *             list in a function declarator that is part of a
3101          *             definition of that function shall not have
3102          *             incomplete type. */
3103         type_t *type = skip_typeref(entity->declaration.type);
3104         if (is_type_incomplete(type)) {
3105                 errorf(&entity->base.source_position, "'%N' has incomplete type", entity);
3106         }
3107 }
3108
3109 static bool has_parameters(void)
3110 {
3111         /* func(void) is not a parameter */
3112         if (look_ahead(1)->kind != ')')
3113                 return true;
3114         if (token.kind == T_IDENTIFIER) {
3115                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3116                 if (entity == NULL)
3117                         return true;
3118                 if (entity->kind != ENTITY_TYPEDEF)
3119                         return true;
3120                 type_t const *const type = skip_typeref(entity->typedefe.type);
3121                 if (!is_type_void(type))
3122                         return true;
3123                 if (c_mode & _CXX) {
3124                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3125                          * is not allowed. */
3126                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3127                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3128                         /* §6.7.5.3:10  Qualification is not allowed here. */
3129                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3130                 }
3131         } else if (token.kind != T_void) {
3132                 return true;
3133         }
3134         next_token();
3135         return false;
3136 }
3137
3138 /**
3139  * Parses function type parameters (and optionally creates variable_t entities
3140  * for them in a scope)
3141  */
3142 static void parse_parameters(function_type_t *type, scope_t *scope)
3143 {
3144         eat('(');
3145         add_anchor_token(')');
3146
3147         if (token.kind == T_IDENTIFIER            &&
3148             !is_typedef_symbol(token.base.symbol) &&
3149             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3150                 type->kr_style_parameters = true;
3151                 parse_identifier_list(scope);
3152         } else if (token.kind == ')') {
3153                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3154                 if (!(c_mode & _CXX))
3155                         type->unspecified_parameters = true;
3156         } else if (has_parameters()) {
3157                 function_parameter_t **anchor = &type->parameters;
3158                 add_anchor_token(',');
3159                 do {
3160                         switch (token.kind) {
3161                         case T_DOTDOTDOT:
3162                                 next_token();
3163                                 type->variadic = true;
3164                                 goto parameters_finished;
3165
3166                         case T_IDENTIFIER:
3167                         DECLARATION_START
3168                         {
3169                                 entity_t *entity = parse_parameter();
3170                                 if (entity->kind == ENTITY_TYPEDEF) {
3171                                         errorf(&entity->base.source_position,
3172                                                         "typedef not allowed as function parameter");
3173                                         break;
3174                                 }
3175                                 assert(is_declaration(entity));
3176
3177                                 semantic_parameter_incomplete(entity);
3178
3179                                 function_parameter_t *const parameter =
3180                                         allocate_parameter(entity->declaration.type);
3181
3182                                 if (scope != NULL) {
3183                                         append_entity(scope, entity);
3184                                 }
3185
3186                                 *anchor = parameter;
3187                                 anchor  = &parameter->next;
3188                                 break;
3189                         }
3190
3191                         default:
3192                                 goto parameters_finished;
3193                         }
3194                 } while (next_if(','));
3195 parameters_finished:
3196                 rem_anchor_token(',');
3197         }
3198
3199         rem_anchor_token(')');
3200         expect(')');
3201 }
3202
3203 typedef enum construct_type_kind_t {
3204         CONSTRUCT_POINTER = 1,
3205         CONSTRUCT_REFERENCE,
3206         CONSTRUCT_FUNCTION,
3207         CONSTRUCT_ARRAY
3208 } construct_type_kind_t;
3209
3210 typedef union construct_type_t construct_type_t;
3211
3212 typedef struct construct_type_base_t {
3213         construct_type_kind_t  kind;
3214         source_position_t      pos;
3215         construct_type_t      *next;
3216 } construct_type_base_t;
3217
3218 typedef struct parsed_pointer_t {
3219         construct_type_base_t  base;
3220         type_qualifiers_t      type_qualifiers;
3221         variable_t            *base_variable;  /**< MS __based extension. */
3222 } parsed_pointer_t;
3223
3224 typedef struct parsed_reference_t {
3225         construct_type_base_t base;
3226 } parsed_reference_t;
3227
3228 typedef struct construct_function_type_t {
3229         construct_type_base_t  base;
3230         type_t                *function_type;
3231 } construct_function_type_t;
3232
3233 typedef struct parsed_array_t {
3234         construct_type_base_t  base;
3235         type_qualifiers_t      type_qualifiers;
3236         bool                   is_static;
3237         bool                   is_variable;
3238         expression_t          *size;
3239 } parsed_array_t;
3240
3241 union construct_type_t {
3242         construct_type_kind_t     kind;
3243         construct_type_base_t     base;
3244         parsed_pointer_t          pointer;
3245         parsed_reference_t        reference;
3246         construct_function_type_t function;
3247         parsed_array_t            array;
3248 };
3249
3250 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3251 {
3252         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3253         memset(cons, 0, size);
3254         cons->kind     = kind;
3255         cons->base.pos = *HERE;
3256         return cons;
3257 }
3258
3259 /* §6.7.5.1 */
3260 static construct_type_t *parse_pointer_declarator(void)
3261 {
3262         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3263         eat('*');
3264         cons->pointer.type_qualifiers = parse_type_qualifiers();
3265         //cons->pointer.base_variable   = base_variable;
3266
3267         return cons;
3268 }
3269
3270 /* ISO/IEC 14882:1998(E) §8.3.2 */
3271 static construct_type_t *parse_reference_declarator(void)
3272 {
3273         if (!(c_mode & _CXX))
3274                 errorf(HERE, "references are only available for C++");
3275
3276         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3277         eat('&');
3278
3279         return cons;
3280 }
3281
3282 /* §6.7.5.2 */
3283 static construct_type_t *parse_array_declarator(void)
3284 {
3285         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3286         parsed_array_t   *const array = &cons->array;
3287
3288         eat('[');
3289         add_anchor_token(']');
3290
3291         bool is_static = next_if(T_static);
3292
3293         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3294
3295         if (!is_static)
3296                 is_static = next_if(T_static);
3297
3298         array->type_qualifiers = type_qualifiers;
3299         array->is_static       = is_static;
3300
3301         expression_t *size = NULL;
3302         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3303                 array->is_variable = true;
3304                 next_token();
3305         } else if (token.kind != ']') {
3306                 size = parse_assignment_expression();
3307
3308                 /* §6.7.5.2:1  Array size must have integer type */
3309                 type_t *const orig_type = size->base.type;
3310                 type_t *const type      = skip_typeref(orig_type);
3311                 if (!is_type_integer(type) && is_type_valid(type)) {
3312                         errorf(&size->base.source_position,
3313                                "array size '%E' must have integer type but has type '%T'",
3314                                size, orig_type);
3315                 }
3316
3317                 array->size = size;
3318                 mark_vars_read(size, NULL);
3319         }
3320
3321         if (is_static && size == NULL)
3322                 errorf(&array->base.pos, "static array parameters require a size");
3323
3324         rem_anchor_token(']');
3325         expect(']');
3326         return cons;
3327 }
3328
3329 /* §6.7.5.3 */
3330 static construct_type_t *parse_function_declarator(scope_t *scope)
3331 {
3332         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3333
3334         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3335         function_type_t *ftype = &type->function;
3336
3337         ftype->linkage            = current_linkage;
3338         ftype->calling_convention = CC_DEFAULT;
3339
3340         parse_parameters(ftype, scope);
3341
3342         cons->function.function_type = type;
3343
3344         return cons;
3345 }
3346
3347 typedef struct parse_declarator_env_t {
3348         bool               may_be_abstract : 1;
3349         bool               must_be_abstract : 1;
3350         decl_modifiers_t   modifiers;
3351         symbol_t          *symbol;
3352         source_position_t  source_position;
3353         scope_t            parameters;
3354         attribute_t       *attributes;
3355 } parse_declarator_env_t;
3356
3357 /* §6.7.5 */
3358 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3359 {
3360         /* construct a single linked list of construct_type_t's which describe
3361          * how to construct the final declarator type */
3362         construct_type_t  *first      = NULL;
3363         construct_type_t **anchor     = &first;
3364
3365         env->attributes = parse_attributes(env->attributes);
3366
3367         for (;;) {
3368                 construct_type_t *type;
3369                 //variable_t       *based = NULL; /* MS __based extension */
3370                 switch (token.kind) {
3371                         case '&':
3372                                 type = parse_reference_declarator();
3373                                 break;
3374
3375                         case T__based: {
3376                                 panic("based not supported anymore");
3377                                 /* FALLTHROUGH */
3378                         }
3379
3380                         case '*':
3381                                 type = parse_pointer_declarator();
3382                                 break;
3383
3384                         default:
3385                                 goto ptr_operator_end;
3386                 }
3387
3388                 *anchor = type;
3389                 anchor  = &type->base.next;
3390
3391                 /* TODO: find out if this is correct */
3392                 env->attributes = parse_attributes(env->attributes);
3393         }
3394
3395 ptr_operator_end: ;
3396         construct_type_t *inner_types = NULL;
3397
3398         switch (token.kind) {
3399         case T_IDENTIFIER:
3400                 if (env->must_be_abstract) {
3401                         errorf(HERE, "no identifier expected in typename");
3402                 } else {
3403                         env->symbol          = token.base.symbol;
3404                         env->source_position = *HERE;
3405                 }
3406                 next_token();
3407                 break;
3408
3409         case '(': {
3410                 /* Parenthesized declarator or function declarator? */
3411                 token_t const *const la1 = look_ahead(1);
3412                 switch (la1->kind) {
3413                         case T_IDENTIFIER:
3414                                 if (is_typedef_symbol(la1->base.symbol)) {
3415                         case ')':
3416                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3417                                          * interpreted as ``function with no parameter specification'', rather
3418                                          * than redundant parentheses around the omitted identifier. */
3419                         default:
3420                                         /* Function declarator. */
3421                                         if (!env->may_be_abstract) {
3422                                                 errorf(HERE, "function declarator must have a name");
3423                                         }
3424                                 } else {
3425                         case '&':
3426                         case '(':
3427                         case '*':
3428                         case '[':
3429                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3430                                         /* Paranthesized declarator. */
3431                                         next_token();
3432                                         add_anchor_token(')');
3433                                         inner_types = parse_inner_declarator(env);
3434                                         if (inner_types != NULL) {
3435                                                 /* All later declarators only modify the return type */
3436                                                 env->must_be_abstract = true;
3437                                         }
3438                                         rem_anchor_token(')');
3439                                         expect(')');
3440                                 }
3441                                 break;
3442                 }
3443                 break;
3444         }
3445
3446         default:
3447                 if (env->may_be_abstract)
3448                         break;
3449                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3450                 eat_until_anchor();
3451                 return NULL;
3452         }
3453
3454         construct_type_t **const p = anchor;
3455
3456         for (;;) {
3457                 construct_type_t *type;
3458                 switch (token.kind) {
3459                 case '(': {
3460                         scope_t *scope = NULL;
3461                         if (!env->must_be_abstract) {
3462                                 scope = &env->parameters;
3463                         }
3464
3465                         type = parse_function_declarator(scope);
3466                         break;
3467                 }
3468                 case '[':
3469                         type = parse_array_declarator();
3470                         break;
3471                 default:
3472                         goto declarator_finished;
3473                 }
3474
3475                 /* insert in the middle of the list (at p) */
3476                 type->base.next = *p;
3477                 *p              = type;
3478                 if (anchor == p)
3479                         anchor = &type->base.next;
3480         }
3481
3482 declarator_finished:
3483         /* append inner_types at the end of the list, we don't to set anchor anymore
3484          * as it's not needed anymore */
3485         *anchor = inner_types;
3486
3487         return first;
3488 }
3489
3490 static type_t *construct_declarator_type(construct_type_t *construct_list,
3491                                          type_t *type)
3492 {
3493         construct_type_t *iter = construct_list;
3494         for (; iter != NULL; iter = iter->base.next) {
3495                 source_position_t const* const pos = &iter->base.pos;
3496                 switch (iter->kind) {
3497                 case CONSTRUCT_FUNCTION: {
3498                         construct_function_type_t *function      = &iter->function;
3499                         type_t                    *function_type = function->function_type;
3500
3501                         function_type->function.return_type = type;
3502
3503                         type_t *skipped_return_type = skip_typeref(type);
3504                         /* §6.7.5.3:1 */
3505                         if (is_type_function(skipped_return_type)) {
3506                                 errorf(pos, "function returning function is not allowed");
3507                         } else if (is_type_array(skipped_return_type)) {
3508                                 errorf(pos, "function returning array is not allowed");
3509                         } else {
3510                                 if (skipped_return_type->base.qualifiers != 0) {
3511                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3512                                 }
3513                         }
3514
3515                         /* The function type was constructed earlier.  Freeing it here will
3516                          * destroy other types. */
3517                         type = typehash_insert(function_type);
3518                         continue;
3519                 }
3520
3521                 case CONSTRUCT_POINTER: {
3522                         if (is_type_reference(skip_typeref(type)))
3523                                 errorf(pos, "cannot declare a pointer to reference");
3524
3525                         parsed_pointer_t *pointer = &iter->pointer;
3526                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3527                         continue;
3528                 }
3529
3530                 case CONSTRUCT_REFERENCE:
3531                         if (is_type_reference(skip_typeref(type)))
3532                                 errorf(pos, "cannot declare a reference to reference");
3533
3534                         type = make_reference_type(type);
3535                         continue;
3536
3537                 case CONSTRUCT_ARRAY: {
3538                         if (is_type_reference(skip_typeref(type)))
3539                                 errorf(pos, "cannot declare an array of references");
3540
3541                         parsed_array_t *array      = &iter->array;
3542                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3543
3544                         expression_t *size_expression = array->size;
3545                         if (size_expression != NULL) {
3546                                 size_expression
3547                                         = create_implicit_cast(size_expression, type_size_t);
3548                         }
3549
3550                         array_type->base.qualifiers       = array->type_qualifiers;
3551                         array_type->array.element_type    = type;
3552                         array_type->array.is_static       = array->is_static;
3553                         array_type->array.is_variable     = array->is_variable;
3554                         array_type->array.size_expression = size_expression;
3555
3556                         if (size_expression != NULL) {
3557                                 switch (is_constant_expression(size_expression)) {
3558                                 case EXPR_CLASS_CONSTANT: {
3559                                         long const size = fold_constant_to_int(size_expression);
3560                                         array_type->array.size          = size;
3561                                         array_type->array.size_constant = true;
3562                                         /* §6.7.5.2:1  If the expression is a constant expression,
3563                                          * it shall have a value greater than zero. */
3564                                         if (size < 0) {
3565                                                 errorf(&size_expression->base.source_position,
3566                                                            "size of array must be greater than zero");
3567                                         } else if (size == 0 && !GNU_MODE) {
3568                                                 errorf(&size_expression->base.source_position,
3569                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3570                                         }
3571                                         break;
3572                                 }
3573
3574                                 case EXPR_CLASS_VARIABLE:
3575                                         array_type->array.is_vla = true;
3576                                         break;
3577
3578                                 case EXPR_CLASS_ERROR:
3579                                         break;
3580                                 }
3581                         }
3582
3583                         type_t *skipped_type = skip_typeref(type);
3584                         /* §6.7.5.2:1 */
3585                         if (is_type_incomplete(skipped_type)) {
3586                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3587                         } else if (is_type_function(skipped_type)) {
3588                                 errorf(pos, "array of functions is not allowed");
3589                         }
3590                         type = identify_new_type(array_type);
3591                         continue;
3592                 }
3593                 }
3594                 internal_errorf(pos, "invalid type construction found");
3595         }
3596
3597         return type;
3598 }
3599
3600 static type_t *automatic_type_conversion(type_t *orig_type);
3601
3602 static type_t *semantic_parameter(const source_position_t *pos,
3603                                   type_t *type,
3604                                   const declaration_specifiers_t *specifiers,
3605                                   entity_t const *const param)
3606 {
3607         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3608          *             shall be adjusted to ``qualified pointer to type'',
3609          *             [...]
3610          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3611          *             type'' shall be adjusted to ``pointer to function
3612          *             returning type'', as in 6.3.2.1. */
3613         type = automatic_type_conversion(type);
3614
3615         if (specifiers->is_inline && is_type_valid(type)) {
3616                 errorf(pos, "'%N' declared 'inline'", param);
3617         }
3618
3619         /* §6.9.1:6  The declarations in the declaration list shall contain
3620          *           no storage-class specifier other than register and no
3621          *           initializations. */
3622         if (specifiers->thread_local || (
3623                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3624                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3625            ) {
3626                 errorf(pos, "invalid storage class for '%N'", param);
3627         }
3628
3629         /* delay test for incomplete type, because we might have (void)
3630          * which is legal but incomplete... */
3631
3632         return type;
3633 }
3634
3635 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3636                                   declarator_flags_t flags)
3637 {
3638         parse_declarator_env_t env;
3639         memset(&env, 0, sizeof(env));
3640         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3641
3642         construct_type_t *construct_type = parse_inner_declarator(&env);
3643         type_t           *orig_type      =
3644                 construct_declarator_type(construct_type, specifiers->type);
3645         type_t           *type           = skip_typeref(orig_type);
3646
3647         if (construct_type != NULL) {
3648                 obstack_free(&temp_obst, construct_type);
3649         }
3650
3651         attribute_t *attributes = parse_attributes(env.attributes);
3652         /* append (shared) specifier attribute behind attributes of this
3653          * declarator */
3654         attribute_t **anchor = &attributes;
3655         while (*anchor != NULL)
3656                 anchor = &(*anchor)->next;
3657         *anchor = specifiers->attributes;
3658
3659         entity_t *entity;
3660         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3661                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.source_position);
3662                 entity->typedefe.type = orig_type;
3663
3664                 if (anonymous_entity != NULL) {
3665                         if (is_type_compound(type)) {
3666                                 assert(anonymous_entity->compound.alias == NULL);
3667                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3668                                        anonymous_entity->kind == ENTITY_UNION);
3669                                 anonymous_entity->compound.alias = entity;
3670                                 anonymous_entity = NULL;
3671                         } else if (is_type_enum(type)) {
3672                                 assert(anonymous_entity->enume.alias == NULL);
3673                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3674                                 anonymous_entity->enume.alias = entity;
3675                                 anonymous_entity = NULL;
3676                         }
3677                 }
3678         } else {
3679                 /* create a declaration type entity */
3680                 source_position_t const *const pos = env.symbol ? &env.source_position : &specifiers->source_position;
3681                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3682                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3683
3684                         if (env.symbol != NULL) {
3685                                 if (specifiers->is_inline && is_type_valid(type)) {
3686                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3687                                 }
3688
3689                                 if (specifiers->thread_local ||
3690                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3691                                         errorf(&env.source_position, "'%N' must have no storage class", entity);
3692                                 }
3693                         }
3694                 } else if (flags & DECL_IS_PARAMETER) {
3695                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3696                         orig_type = semantic_parameter(&env.source_position, orig_type, specifiers, entity);
3697                 } else if (is_type_function(type)) {
3698                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3699                         entity->function.is_inline      = specifiers->is_inline;
3700                         entity->function.elf_visibility = default_visibility;
3701                         entity->function.parameters     = env.parameters;
3702
3703                         if (env.symbol != NULL) {
3704                                 /* this needs fixes for C++ */
3705                                 bool in_function_scope = current_function != NULL;
3706
3707                                 if (specifiers->thread_local || (
3708                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3709                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3710                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3711                                                 )) {
3712                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3713                                 }
3714                         }
3715                 } else {
3716                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3717                         entity->variable.elf_visibility = default_visibility;
3718                         entity->variable.thread_local   = specifiers->thread_local;
3719
3720                         if (env.symbol != NULL) {
3721                                 if (specifiers->is_inline && is_type_valid(type)) {
3722                                         errorf(&env.source_position, "'%N' declared 'inline'", entity);
3723                                 }
3724
3725                                 bool invalid_storage_class = false;
3726                                 if (current_scope == file_scope) {
3727                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3728                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3729                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3730                                                 invalid_storage_class = true;
3731                                         }
3732                                 } else {
3733                                         if (specifiers->thread_local &&
3734                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3735                                                 invalid_storage_class = true;
3736                                         }
3737                                 }
3738                                 if (invalid_storage_class) {
3739                                         errorf(&env.source_position, "invalid storage class for '%N'", entity);
3740                                 }
3741                         }
3742                 }
3743
3744                 entity->declaration.type       = orig_type;
3745                 entity->declaration.alignment  = get_type_alignment(orig_type);
3746                 entity->declaration.modifiers  = env.modifiers;
3747                 entity->declaration.attributes = attributes;
3748
3749                 storage_class_t storage_class = specifiers->storage_class;
3750                 entity->declaration.declared_storage_class = storage_class;
3751
3752                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3753                         storage_class = STORAGE_CLASS_AUTO;
3754                 entity->declaration.storage_class = storage_class;
3755         }
3756
3757         if (attributes != NULL) {
3758                 handle_entity_attributes(attributes, entity);
3759         }
3760
3761         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3762                 adapt_special_functions(&entity->function);
3763         }
3764
3765         return entity;
3766 }
3767
3768 static type_t *parse_abstract_declarator(type_t *base_type)
3769 {
3770         parse_declarator_env_t env;
3771         memset(&env, 0, sizeof(env));
3772         env.may_be_abstract = true;
3773         env.must_be_abstract = true;
3774
3775         construct_type_t *construct_type = parse_inner_declarator(&env);
3776
3777         type_t *result = construct_declarator_type(construct_type, base_type);
3778         if (construct_type != NULL) {
3779                 obstack_free(&temp_obst, construct_type);
3780         }
3781         result = handle_type_attributes(env.attributes, result);
3782
3783         return result;
3784 }
3785
3786 /**
3787  * Check if the declaration of main is suspicious.  main should be a
3788  * function with external linkage, returning int, taking either zero
3789  * arguments, two, or three arguments of appropriate types, ie.
3790  *
3791  * int main([ int argc, char **argv [, char **env ] ]).
3792  *
3793  * @param decl    the declaration to check
3794  * @param type    the function type of the declaration
3795  */
3796 static void check_main(const entity_t *entity)
3797 {
3798         const source_position_t *pos = &entity->base.source_position;
3799         if (entity->kind != ENTITY_FUNCTION) {
3800                 warningf(WARN_MAIN, pos, "'main' is not a function");
3801                 return;
3802         }
3803
3804         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3805                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3806         }
3807
3808         type_t *type = skip_typeref(entity->declaration.type);
3809         assert(is_type_function(type));
3810
3811         function_type_t const *const func_type = &type->function;
3812         type_t                *const ret_type  = func_type->return_type;
3813         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3814                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3815         }
3816         const function_parameter_t *parm = func_type->parameters;
3817         if (parm != NULL) {
3818                 type_t *const first_type        = skip_typeref(parm->type);
3819                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3820                 if (!types_compatible(first_type_unqual, type_int)) {
3821                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3822                 }
3823                 parm = parm->next;
3824                 if (parm != NULL) {
3825                         type_t *const second_type = skip_typeref(parm->type);
3826                         type_t *const second_type_unqual
3827                                 = get_unqualified_type(second_type);
3828                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3829                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3830                         }
3831                         parm = parm->next;
3832                         if (parm != NULL) {
3833                                 type_t *const third_type = skip_typeref(parm->type);
3834                                 type_t *const third_type_unqual
3835                                         = get_unqualified_type(third_type);
3836                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3837                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3838                                 }
3839                                 parm = parm->next;
3840                                 if (parm != NULL)
3841                                         goto warn_arg_count;
3842                         }
3843                 } else {
3844 warn_arg_count:
3845                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3846                 }
3847         }
3848 }
3849
3850 static void error_redefined_as_different_kind(const source_position_t *pos,
3851                 const entity_t *old, entity_kind_t new_kind)
3852 {
3853         char              const *const what = get_entity_kind_name(new_kind);
3854         source_position_t const *const ppos = &old->base.source_position;
3855         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3856 }
3857
3858 static bool is_entity_valid(entity_t *const ent)
3859 {
3860         if (is_declaration(ent)) {
3861                 return is_type_valid(skip_typeref(ent->declaration.type));
3862         } else if (ent->kind == ENTITY_TYPEDEF) {
3863                 return is_type_valid(skip_typeref(ent->typedefe.type));
3864         }
3865         return true;
3866 }
3867
3868 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3869 {
3870         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3871                 if (attributes_equal(tattr, attr))
3872                         return true;
3873         }
3874         return false;
3875 }
3876
3877 /**
3878  * test wether new_list contains any attributes not included in old_list
3879  */
3880 static bool has_new_attributes(const attribute_t *old_list,
3881                                const attribute_t *new_list)
3882 {
3883         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3884                 if (!contains_attribute(old_list, attr))
3885                         return true;
3886         }
3887         return false;
3888 }
3889
3890 /**
3891  * Merge in attributes from an attribute list (probably from a previous
3892  * declaration with the same name). Warning: destroys the old structure
3893  * of the attribute list - don't reuse attributes after this call.
3894  */
3895 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3896 {
3897         attribute_t *next;
3898         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3899                 next = attr->next;
3900                 if (contains_attribute(decl->attributes, attr))
3901                         continue;
3902
3903                 /* move attribute to new declarations attributes list */
3904                 attr->next       = decl->attributes;
3905                 decl->attributes = attr;
3906         }
3907 }
3908
3909 static bool is_main(entity_t*);
3910
3911 /**
3912  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3913  * for various problems that occur for multiple definitions
3914  */
3915 entity_t *record_entity(entity_t *entity, const bool is_definition)
3916 {
3917         const symbol_t *const    symbol  = entity->base.symbol;
3918         const namespace_tag_t    namespc = (namespace_tag_t)entity->base.namespc;
3919         const source_position_t *pos     = &entity->base.source_position;
3920
3921         /* can happen in error cases */
3922         if (symbol == NULL)
3923                 return entity;
3924
3925         assert(!entity->base.parent_scope);
3926         assert(current_scope);
3927         entity->base.parent_scope = current_scope;
3928
3929         entity_t *const previous_entity = get_entity(symbol, namespc);
3930         /* pushing the same entity twice will break the stack structure */
3931         assert(previous_entity != entity);
3932
3933         if (entity->kind == ENTITY_FUNCTION) {
3934                 type_t *const orig_type = entity->declaration.type;
3935                 type_t *const type      = skip_typeref(orig_type);
3936
3937                 assert(is_type_function(type));
3938                 if (type->function.unspecified_parameters &&
3939                     previous_entity == NULL               &&
3940                     !entity->declaration.implicit) {
3941                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3942                 }
3943
3944                 if (is_main(entity)) {
3945                         check_main(entity);
3946                 }
3947         }
3948
3949         if (is_declaration(entity)                                    &&
3950             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3951             current_scope != file_scope                               &&
3952             !entity->declaration.implicit) {
3953                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3954         }
3955
3956         if (previous_entity != NULL) {
3957                 source_position_t const *const ppos = &previous_entity->base.source_position;
3958
3959                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3960                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3961                         assert(previous_entity->kind == ENTITY_PARAMETER);
3962                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3963                         goto finish;
3964                 }
3965
3966                 if (previous_entity->base.parent_scope == current_scope) {
3967                         if (previous_entity->kind != entity->kind) {
3968                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3969                                         error_redefined_as_different_kind(pos, previous_entity,
3970                                                         entity->kind);
3971                                 }
3972                                 goto finish;
3973                         }
3974                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3975                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3976                                 goto finish;
3977                         }
3978                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3979                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3980                                 type_t *const prev_type
3981                                         = skip_typeref(previous_entity->typedefe.type);
3982                                 if (c_mode & _CXX) {
3983                                         /* C++ allows double typedef if they are identical
3984                                          * (after skipping typedefs) */
3985                                         if (type == prev_type)
3986                                                 goto finish;
3987                                 } else {
3988                                         /* GCC extension: redef in system headers is allowed */
3989                                         if ((pos->is_system_header || ppos->is_system_header) &&
3990                                             types_compatible(type, prev_type))
3991                                                 goto finish;
3992                                 }
3993                                 errorf(pos, "redefinition of '%N' (declared %P)",
3994                                        entity, ppos);
3995                                 goto finish;
3996                         }
3997
3998                         /* at this point we should have only VARIABLES or FUNCTIONS */
3999                         assert(is_declaration(previous_entity) && is_declaration(entity));
4000
4001                         declaration_t *const prev_decl = &previous_entity->declaration;
4002                         declaration_t *const decl      = &entity->declaration;
4003
4004                         /* can happen for K&R style declarations */
4005                         if (prev_decl->type       == NULL             &&
4006                                         previous_entity->kind == ENTITY_PARAMETER &&
4007                                         entity->kind          == ENTITY_PARAMETER) {
4008                                 prev_decl->type                   = decl->type;
4009                                 prev_decl->storage_class          = decl->storage_class;
4010                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4011                                 prev_decl->modifiers              = decl->modifiers;
4012                                 return previous_entity;
4013                         }
4014
4015                         type_t *const type      = skip_typeref(decl->type);
4016                         type_t *const prev_type = skip_typeref(prev_decl->type);
4017
4018                         if (!types_compatible(type, prev_type)) {
4019                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4020                         } else {
4021                                 unsigned old_storage_class = prev_decl->storage_class;
4022
4023                                 if (is_definition                     &&
4024                                                 !prev_decl->used                  &&
4025                                                 !(prev_decl->modifiers & DM_USED) &&
4026                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4027                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4028                                 }
4029
4030                                 storage_class_t new_storage_class = decl->storage_class;
4031
4032                                 /* pretend no storage class means extern for function
4033                                  * declarations (except if the previous declaration is neither
4034                                  * none nor extern) */
4035                                 if (entity->kind == ENTITY_FUNCTION) {
4036                                         /* the previous declaration could have unspecified parameters or
4037                                          * be a typedef, so use the new type */
4038                                         if (prev_type->function.unspecified_parameters || is_definition)
4039                                                 prev_decl->type = type;
4040
4041                                         switch (old_storage_class) {
4042                                                 case STORAGE_CLASS_NONE:
4043                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4044                                                         /* FALLTHROUGH */
4045
4046                                                 case STORAGE_CLASS_EXTERN:
4047                                                         if (is_definition) {
4048                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4049                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4050                                                                 }
4051                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4052                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4053                                                         }
4054                                                         break;
4055
4056                                                 default:
4057                                                         break;
4058                                         }
4059                                 } else if (is_type_incomplete(prev_type)) {
4060                                         prev_decl->type = type;
4061                                 }
4062
4063                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4064                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4065
4066 warn_redundant_declaration: ;
4067                                         bool has_new_attrs
4068                                                 = has_new_attributes(prev_decl->attributes,
4069                                                                      decl->attributes);
4070                                         if (has_new_attrs) {
4071                                                 merge_in_attributes(decl, prev_decl->attributes);
4072                                         } else if (!is_definition        &&
4073                                                         is_type_valid(prev_type) &&
4074                                                         !pos->is_system_header) {
4075                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4076                                         }
4077                                 } else if (current_function == NULL) {
4078                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4079                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4080                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4081                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4082                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4083                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4084                                         } else {
4085                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4086                                                 if (c_mode & _CXX)
4087                                                         goto error_redeclaration;
4088                                                 goto warn_redundant_declaration;
4089                                         }
4090                                 } else if (is_type_valid(prev_type)) {
4091                                         if (old_storage_class == new_storage_class) {
4092 error_redeclaration:
4093                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4094                                         } else {
4095                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4096                                         }
4097                                 }
4098                         }
4099
4100                         prev_decl->modifiers |= decl->modifiers;
4101                         if (entity->kind == ENTITY_FUNCTION) {
4102                                 previous_entity->function.is_inline |= entity->function.is_inline;
4103                         }
4104                         return previous_entity;
4105                 }
4106
4107                 warning_t why;
4108                 if (is_warn_on(why = WARN_SHADOW) ||
4109                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4110                         char const *const what = get_entity_kind_name(previous_entity->kind);
4111                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4112                 }
4113         }
4114
4115         if (entity->kind == ENTITY_FUNCTION) {
4116                 if (is_definition &&
4117                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4118                                 !is_main(entity)) {
4119                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4120                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4121                         } else {
4122                                 goto warn_missing_declaration;
4123                         }
4124                 }
4125         } else if (entity->kind == ENTITY_VARIABLE) {
4126                 if (current_scope                     == file_scope &&
4127                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4128                                 !entity->declaration.implicit) {
4129 warn_missing_declaration:
4130                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4131                 }
4132         }
4133
4134 finish:
4135         environment_push(entity);
4136         append_entity(current_scope, entity);
4137
4138         return entity;
4139 }
4140
4141 static void parser_error_multiple_definition(entity_t *entity,
4142                 const source_position_t *source_position)
4143 {
4144         errorf(source_position, "redefinition of '%N' (declared %P)", entity, &entity->base.source_position);
4145 }
4146
4147 static bool is_declaration_specifier(const token_t *token)
4148 {
4149         switch (token->kind) {
4150                 DECLARATION_START
4151                         return true;
4152                 case T_IDENTIFIER:
4153                         return is_typedef_symbol(token->base.symbol);
4154
4155                 default:
4156                         return false;
4157         }
4158 }
4159
4160 static void parse_init_declarator_rest(entity_t *entity)
4161 {
4162         type_t *orig_type = type_error_type;
4163
4164         if (entity->base.kind == ENTITY_TYPEDEF) {
4165                 source_position_t const *const pos = &entity->base.source_position;
4166                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4167         } else {
4168                 assert(is_declaration(entity));
4169                 orig_type = entity->declaration.type;
4170         }
4171
4172         type_t *type = skip_typeref(orig_type);
4173
4174         if (entity->kind == ENTITY_VARIABLE
4175                         && entity->variable.initializer != NULL) {
4176                 parser_error_multiple_definition(entity, HERE);
4177         }
4178         eat('=');
4179
4180         declaration_t *const declaration = &entity->declaration;
4181         bool must_be_constant = false;
4182         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4183             entity->base.parent_scope  == file_scope) {
4184                 must_be_constant = true;
4185         }
4186
4187         if (is_type_function(type)) {
4188                 source_position_t const *const pos = &entity->base.source_position;
4189                 errorf(pos, "'%N' is initialized like a variable", entity);
4190                 orig_type = type_error_type;
4191         }
4192
4193         parse_initializer_env_t env;
4194         env.type             = orig_type;
4195         env.must_be_constant = must_be_constant;
4196         env.entity           = entity;
4197
4198         initializer_t *initializer = parse_initializer(&env);
4199
4200         if (entity->kind == ENTITY_VARIABLE) {
4201                 /* §6.7.5:22  array initializers for arrays with unknown size
4202                  * determine the array type size */
4203                 declaration->type            = env.type;
4204                 entity->variable.initializer = initializer;
4205         }
4206 }
4207
4208 /* parse rest of a declaration without any declarator */
4209 static void parse_anonymous_declaration_rest(
4210                 const declaration_specifiers_t *specifiers)
4211 {
4212         eat(';');
4213         anonymous_entity = NULL;
4214
4215         source_position_t const *const pos = &specifiers->source_position;
4216         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4217                         specifiers->thread_local) {
4218                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4219         }
4220
4221         type_t *type = specifiers->type;
4222         switch (type->kind) {
4223                 case TYPE_COMPOUND_STRUCT:
4224                 case TYPE_COMPOUND_UNION: {
4225                         if (type->compound.compound->base.symbol == NULL) {
4226                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4227                         }
4228                         break;
4229                 }
4230
4231                 case TYPE_ENUM:
4232                         break;
4233
4234                 default:
4235                         warningf(WARN_OTHER, pos, "empty declaration");
4236                         break;
4237         }
4238 }
4239
4240 static void check_variable_type_complete(entity_t *ent)
4241 {
4242         if (ent->kind != ENTITY_VARIABLE)
4243                 return;
4244
4245         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4246          *         type for the object shall be complete [...] */
4247         declaration_t *decl = &ent->declaration;
4248         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4249                         decl->storage_class == STORAGE_CLASS_STATIC)
4250                 return;
4251
4252         type_t *const type = skip_typeref(decl->type);
4253         if (!is_type_incomplete(type))
4254                 return;
4255
4256         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4257          * are given length one. */
4258         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4259                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4260                 return;
4261         }
4262
4263         errorf(&ent->base.source_position, "variable '%#N' has incomplete type", ent);
4264 }
4265
4266
4267 static void parse_declaration_rest(entity_t *ndeclaration,
4268                 const declaration_specifiers_t *specifiers,
4269                 parsed_declaration_func         finished_declaration,
4270                 declarator_flags_t              flags)
4271 {
4272         add_anchor_token(';');
4273         add_anchor_token(',');
4274         while (true) {
4275                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4276
4277                 if (token.kind == '=') {
4278                         parse_init_declarator_rest(entity);
4279                 } else if (entity->kind == ENTITY_VARIABLE) {
4280                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4281                          * [...] where the extern specifier is explicitly used. */
4282                         declaration_t *decl = &entity->declaration;
4283                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4284                             is_type_reference(skip_typeref(decl->type))) {
4285                                 source_position_t const *const pos = &entity->base.source_position;
4286                                 errorf(pos, "reference '%#N' must be initialized", entity);
4287                         }
4288                 }
4289
4290                 check_variable_type_complete(entity);
4291
4292                 if (!next_if(','))
4293                         break;
4294
4295                 add_anchor_token('=');
4296                 ndeclaration = parse_declarator(specifiers, flags);
4297                 rem_anchor_token('=');
4298         }
4299         rem_anchor_token(',');
4300         rem_anchor_token(';');
4301         expect(';');
4302
4303         anonymous_entity = NULL;
4304 }
4305
4306 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4307 {
4308         symbol_t *symbol = entity->base.symbol;
4309         if (symbol == NULL)
4310                 return entity;
4311
4312         assert(entity->base.namespc == NAMESPACE_NORMAL);
4313         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4314         if (previous_entity == NULL
4315                         || previous_entity->base.parent_scope != current_scope) {
4316                 errorf(&entity->base.source_position, "expected declaration of a function parameter, found '%Y'",
4317                        symbol);
4318                 return entity;
4319         }
4320
4321         if (is_definition) {
4322                 errorf(HERE, "'%N' is initialised", entity);
4323         }
4324
4325         return record_entity(entity, false);
4326 }
4327
4328 static void parse_declaration(parsed_declaration_func finished_declaration,
4329                               declarator_flags_t      flags)
4330 {
4331         add_anchor_token(';');
4332         declaration_specifiers_t specifiers;
4333         parse_declaration_specifiers(&specifiers);
4334         rem_anchor_token(';');
4335
4336         if (token.kind == ';') {
4337                 parse_anonymous_declaration_rest(&specifiers);
4338         } else {
4339                 entity_t *entity = parse_declarator(&specifiers, flags);
4340                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4341         }
4342 }
4343
4344 /* §6.5.2.2:6 */
4345 static type_t *get_default_promoted_type(type_t *orig_type)
4346 {
4347         type_t *result = orig_type;
4348
4349         type_t *type = skip_typeref(orig_type);
4350         if (is_type_integer(type)) {
4351                 result = promote_integer(type);
4352         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4353                 result = type_double;
4354         }
4355
4356         return result;
4357 }
4358
4359 static void parse_kr_declaration_list(entity_t *entity)
4360 {
4361         if (entity->kind != ENTITY_FUNCTION)
4362                 return;
4363
4364         type_t *type = skip_typeref(entity->declaration.type);
4365         assert(is_type_function(type));
4366         if (!type->function.kr_style_parameters)
4367                 return;
4368
4369         add_anchor_token('{');
4370
4371         PUSH_SCOPE(&entity->function.parameters);
4372
4373         entity_t *parameter = entity->function.parameters.entities;
4374         for ( ; parameter != NULL; parameter = parameter->base.next) {
4375                 assert(parameter->base.parent_scope == NULL);
4376                 parameter->base.parent_scope = current_scope;
4377                 environment_push(parameter);
4378         }
4379
4380         /* parse declaration list */
4381         for (;;) {
4382                 switch (token.kind) {
4383                         DECLARATION_START
4384                         /* This covers symbols, which are no type, too, and results in
4385                          * better error messages.  The typical cases are misspelled type
4386                          * names and missing includes. */
4387                         case T_IDENTIFIER:
4388                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4389                                 break;
4390                         default:
4391                                 goto decl_list_end;
4392                 }
4393         }
4394 decl_list_end:
4395
4396         POP_SCOPE();
4397
4398         /* update function type */
4399         type_t *new_type = duplicate_type(type);
4400
4401         function_parameter_t  *parameters = NULL;
4402         function_parameter_t **anchor     = &parameters;
4403
4404         /* did we have an earlier prototype? */
4405         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4406         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4407                 proto_type = NULL;
4408
4409         function_parameter_t *proto_parameter = NULL;
4410         if (proto_type != NULL) {
4411                 type_t *proto_type_type = proto_type->declaration.type;
4412                 proto_parameter         = proto_type_type->function.parameters;
4413                 /* If a K&R function definition has a variadic prototype earlier, then
4414                  * make the function definition variadic, too. This should conform to
4415                  * §6.7.5.3:15 and §6.9.1:8. */
4416                 new_type->function.variadic = proto_type_type->function.variadic;
4417         } else {
4418                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4419                  * prototype */
4420                 new_type->function.unspecified_parameters = true;
4421         }
4422
4423         bool need_incompatible_warning = false;
4424         parameter = entity->function.parameters.entities;
4425         for (; parameter != NULL; parameter = parameter->base.next,
4426                         proto_parameter =
4427                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4428                 if (parameter->kind != ENTITY_PARAMETER)
4429                         continue;
4430
4431                 type_t *parameter_type = parameter->declaration.type;
4432                 if (parameter_type == NULL) {
4433                         source_position_t const* const pos = &parameter->base.source_position;
4434                         if (strict_mode) {
4435                                 errorf(pos, "no type specified for function '%N'", parameter);
4436                                 parameter_type = type_error_type;
4437                         } else {
4438                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4439                                 parameter_type = type_int;
4440                         }
4441                         parameter->declaration.type = parameter_type;
4442                 }
4443
4444                 semantic_parameter_incomplete(parameter);
4445
4446                 /* we need the default promoted types for the function type */
4447                 type_t *not_promoted = parameter_type;
4448                 parameter_type       = get_default_promoted_type(parameter_type);
4449
4450                 /* gcc special: if the type of the prototype matches the unpromoted
4451                  * type don't promote */
4452                 if (!strict_mode && proto_parameter != NULL) {
4453                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4454                         type_t *promo_skip   = skip_typeref(parameter_type);
4455                         type_t *param_skip   = skip_typeref(not_promoted);
4456                         if (!types_compatible(proto_p_type, promo_skip)
4457                                 && types_compatible(proto_p_type, param_skip)) {
4458                                 /* don't promote */
4459                                 need_incompatible_warning = true;
4460                                 parameter_type = not_promoted;
4461                         }
4462                 }
4463                 function_parameter_t *const function_parameter
4464                         = allocate_parameter(parameter_type);
4465
4466                 *anchor = function_parameter;
4467                 anchor  = &function_parameter->next;
4468         }
4469
4470         new_type->function.parameters = parameters;
4471         new_type = identify_new_type(new_type);
4472
4473         if (need_incompatible_warning) {
4474                 symbol_t          const *const sym  = entity->base.symbol;
4475                 source_position_t const *const pos  = &entity->base.source_position;
4476                 source_position_t const *const ppos = &proto_type->base.source_position;
4477                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4478         }
4479         entity->declaration.type = new_type;
4480
4481         rem_anchor_token('{');
4482 }
4483
4484 static bool first_err = true;
4485
4486 /**
4487  * When called with first_err set, prints the name of the current function,
4488  * else does noting.
4489  */
4490 static void print_in_function(void)
4491 {
4492         if (first_err) {
4493                 first_err = false;
4494                 char const *const file = current_function->base.base.source_position.input_name;
4495                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4496         }
4497 }
4498
4499 /**
4500  * Check if all labels are defined in the current function.
4501  * Check if all labels are used in the current function.
4502  */
4503 static void check_labels(void)
4504 {
4505         for (const goto_statement_t *goto_statement = goto_first;
4506             goto_statement != NULL;
4507             goto_statement = goto_statement->next) {
4508                 label_t *label = goto_statement->label;
4509                 if (label->base.source_position.input_name == NULL) {
4510                         print_in_function();
4511                         source_position_t const *const pos = &goto_statement->base.source_position;
4512                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4513                  }
4514         }
4515
4516         if (is_warn_on(WARN_UNUSED_LABEL)) {
4517                 for (const label_statement_t *label_statement = label_first;
4518                          label_statement != NULL;
4519                          label_statement = label_statement->next) {
4520                         label_t *label = label_statement->label;
4521
4522                         if (! label->used) {
4523                                 print_in_function();
4524                                 source_position_t const *const pos = &label_statement->base.source_position;
4525                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4526                         }
4527                 }
4528         }
4529 }
4530
4531 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4532 {
4533         entity_t const *const end = last != NULL ? last->base.next : NULL;
4534         for (; entity != end; entity = entity->base.next) {
4535                 if (!is_declaration(entity))
4536                         continue;
4537
4538                 declaration_t *declaration = &entity->declaration;
4539                 if (declaration->implicit)
4540                         continue;
4541
4542                 if (!declaration->used) {
4543                         print_in_function();
4544                         warningf(why, &entity->base.source_position, "'%N' is unused", entity);
4545                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4546                         print_in_function();
4547                         warningf(why, &entity->base.source_position, "'%N' is never read", entity);
4548                 }
4549         }
4550 }
4551
4552 static void check_unused_variables(statement_t *const stmt, void *const env)
4553 {
4554         (void)env;
4555
4556         switch (stmt->kind) {
4557                 case STATEMENT_DECLARATION: {
4558                         declaration_statement_t const *const decls = &stmt->declaration;
4559                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4560                         return;
4561                 }
4562
4563                 case STATEMENT_FOR:
4564                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4565                         return;
4566
4567                 default:
4568                         return;
4569         }
4570 }
4571
4572 /**
4573  * Check declarations of current_function for unused entities.
4574  */
4575 static void check_declarations(void)
4576 {
4577         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4578                 const scope_t *scope = &current_function->parameters;
4579                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4580         }
4581         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4582                 walk_statements(current_function->statement, check_unused_variables,
4583                                 NULL);
4584         }
4585 }
4586
4587 static int determine_truth(expression_t const* const cond)
4588 {
4589         return
4590                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4591                 fold_constant_to_bool(cond)                         ? 1 :
4592                 -1;
4593 }
4594
4595 static void check_reachable(statement_t *);
4596 static bool reaches_end;
4597
4598 static bool expression_returns(expression_t const *const expr)
4599 {
4600         switch (expr->kind) {
4601                 case EXPR_CALL: {
4602                         expression_t const *const func = expr->call.function;
4603                         type_t       const *const type = skip_typeref(func->base.type);
4604                         if (type->kind == TYPE_POINTER) {
4605                                 type_t const *const points_to
4606                                         = skip_typeref(type->pointer.points_to);
4607                                 if (points_to->kind == TYPE_FUNCTION
4608                                     && points_to->function.modifiers & DM_NORETURN)
4609                                         return false;
4610                         }
4611
4612                         if (!expression_returns(func))
4613                                 return false;
4614
4615                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4616                                 if (!expression_returns(arg->expression))
4617                                         return false;
4618                         }
4619
4620                         return true;
4621                 }
4622
4623                 case EXPR_REFERENCE:
4624                 case EXPR_ENUM_CONSTANT:
4625                 case EXPR_LITERAL_CASES:
4626                 case EXPR_STRING_LITERAL:
4627                 case EXPR_WIDE_STRING_LITERAL:
4628                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4629                 case EXPR_LABEL_ADDRESS:
4630                 case EXPR_CLASSIFY_TYPE:
4631                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4632                 case EXPR_ALIGNOF:
4633                 case EXPR_FUNCNAME:
4634                 case EXPR_BUILTIN_CONSTANT_P:
4635                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4636                 case EXPR_OFFSETOF:
4637                 case EXPR_ERROR:
4638                         return true;
4639
4640                 case EXPR_STATEMENT: {
4641                         bool old_reaches_end = reaches_end;
4642                         reaches_end = false;
4643                         check_reachable(expr->statement.statement);
4644                         bool returns = reaches_end;
4645                         reaches_end = old_reaches_end;
4646                         return returns;
4647                 }
4648
4649                 case EXPR_CONDITIONAL:
4650                         // TODO handle constant expression
4651
4652                         if (!expression_returns(expr->conditional.condition))
4653                                 return false;
4654
4655                         if (expr->conditional.true_expression != NULL
4656                                         && expression_returns(expr->conditional.true_expression))
4657                                 return true;
4658
4659                         return expression_returns(expr->conditional.false_expression);
4660
4661                 case EXPR_SELECT:
4662                         return expression_returns(expr->select.compound);
4663
4664                 case EXPR_ARRAY_ACCESS:
4665                         return
4666                                 expression_returns(expr->array_access.array_ref) &&
4667                                 expression_returns(expr->array_access.index);
4668
4669                 case EXPR_VA_START:
4670                         return expression_returns(expr->va_starte.ap);
4671
4672                 case EXPR_VA_ARG:
4673                         return expression_returns(expr->va_arge.ap);
4674
4675                 case EXPR_VA_COPY:
4676                         return expression_returns(expr->va_copye.src);
4677
4678                 case EXPR_UNARY_CASES_MANDATORY:
4679                         return expression_returns(expr->unary.value);
4680
4681                 case EXPR_UNARY_THROW:
4682                         return false;
4683
4684                 case EXPR_BINARY_CASES:
4685                         // TODO handle constant lhs of && and ||
4686                         return
4687                                 expression_returns(expr->binary.left) &&
4688                                 expression_returns(expr->binary.right);
4689         }
4690
4691         panic("unhandled expression");
4692 }
4693
4694 static bool initializer_returns(initializer_t const *const init)
4695 {
4696         switch (init->kind) {
4697                 case INITIALIZER_VALUE:
4698                         return expression_returns(init->value.value);
4699
4700                 case INITIALIZER_LIST: {
4701                         initializer_t * const*       i       = init->list.initializers;
4702                         initializer_t * const* const end     = i + init->list.len;
4703                         bool                         returns = true;
4704                         for (; i != end; ++i) {
4705                                 if (!initializer_returns(*i))
4706                                         returns = false;
4707                         }
4708                         return returns;
4709                 }
4710
4711                 case INITIALIZER_STRING:
4712                 case INITIALIZER_WIDE_STRING:
4713                 case INITIALIZER_DESIGNATOR: // designators have no payload
4714                         return true;
4715         }
4716         panic("unhandled initializer");
4717 }
4718
4719 static bool noreturn_candidate;
4720
4721 static void check_reachable(statement_t *const stmt)
4722 {
4723         if (stmt->base.reachable)
4724                 return;
4725         if (stmt->kind != STATEMENT_DO_WHILE)
4726                 stmt->base.reachable = true;
4727
4728         statement_t *last = stmt;
4729         statement_t *next;
4730         switch (stmt->kind) {
4731                 case STATEMENT_ERROR:
4732                 case STATEMENT_EMPTY:
4733                 case STATEMENT_ASM:
4734                         next = stmt->base.next;
4735                         break;
4736
4737                 case STATEMENT_DECLARATION: {
4738                         declaration_statement_t const *const decl = &stmt->declaration;
4739                         entity_t                const *      ent  = decl->declarations_begin;
4740                         entity_t                const *const last_decl = decl->declarations_end;
4741                         if (ent != NULL) {
4742                                 for (;; ent = ent->base.next) {
4743                                         if (ent->kind                 == ENTITY_VARIABLE &&
4744                                             ent->variable.initializer != NULL            &&
4745                                             !initializer_returns(ent->variable.initializer)) {
4746                                                 return;
4747                                         }
4748                                         if (ent == last_decl)
4749                                                 break;
4750                                 }
4751                         }
4752                         next = stmt->base.next;
4753                         break;
4754                 }
4755
4756                 case STATEMENT_COMPOUND:
4757                         next = stmt->compound.statements;
4758                         if (next == NULL)
4759                                 next = stmt->base.next;
4760                         break;
4761
4762                 case STATEMENT_RETURN: {
4763                         expression_t const *const val = stmt->returns.value;
4764                         if (val == NULL || expression_returns(val))
4765                                 noreturn_candidate = false;
4766                         return;
4767                 }
4768
4769                 case STATEMENT_IF: {
4770                         if_statement_t const *const ifs  = &stmt->ifs;
4771                         expression_t   const *const cond = ifs->condition;
4772
4773                         if (!expression_returns(cond))
4774                                 return;
4775
4776                         int const val = determine_truth(cond);
4777
4778                         if (val >= 0)
4779                                 check_reachable(ifs->true_statement);
4780
4781                         if (val > 0)
4782                                 return;
4783
4784                         if (ifs->false_statement != NULL) {
4785                                 check_reachable(ifs->false_statement);
4786                                 return;
4787                         }
4788
4789                         next = stmt->base.next;
4790                         break;
4791                 }
4792
4793                 case STATEMENT_SWITCH: {
4794                         switch_statement_t const *const switchs = &stmt->switchs;
4795                         expression_t       const *const expr    = switchs->expression;
4796
4797                         if (!expression_returns(expr))
4798                                 return;
4799
4800                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4801                                 long                    const val      = fold_constant_to_int(expr);
4802                                 case_label_statement_t *      defaults = NULL;
4803                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4804                                         if (i->expression == NULL) {
4805                                                 defaults = i;
4806                                                 continue;
4807                                         }
4808
4809                                         if (i->first_case <= val && val <= i->last_case) {
4810                                                 check_reachable((statement_t*)i);
4811                                                 return;
4812                                         }
4813                                 }
4814
4815                                 if (defaults != NULL) {
4816                                         check_reachable((statement_t*)defaults);
4817                                         return;
4818                                 }
4819                         } else {
4820                                 bool has_default = false;
4821                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4822                                         if (i->expression == NULL)
4823                                                 has_default = true;
4824
4825                                         check_reachable((statement_t*)i);
4826                                 }
4827
4828                                 if (has_default)
4829                                         return;
4830                         }
4831
4832                         next = stmt->base.next;
4833                         break;
4834                 }
4835
4836                 case STATEMENT_EXPRESSION: {
4837                         /* Check for noreturn function call */
4838                         expression_t const *const expr = stmt->expression.expression;
4839                         if (!expression_returns(expr))
4840                                 return;
4841
4842                         next = stmt->base.next;
4843                         break;
4844                 }
4845
4846                 case STATEMENT_CONTINUE:
4847                         for (statement_t *parent = stmt;;) {
4848                                 parent = parent->base.parent;
4849                                 if (parent == NULL) /* continue not within loop */
4850                                         return;
4851
4852                                 next = parent;
4853                                 switch (parent->kind) {
4854                                         case STATEMENT_WHILE:    goto continue_while;
4855                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4856                                         case STATEMENT_FOR:      goto continue_for;
4857
4858                                         default: break;
4859                                 }
4860                         }
4861
4862                 case STATEMENT_BREAK:
4863                         for (statement_t *parent = stmt;;) {
4864                                 parent = parent->base.parent;
4865                                 if (parent == NULL) /* break not within loop/switch */
4866                                         return;
4867
4868                                 switch (parent->kind) {
4869                                         case STATEMENT_SWITCH:
4870                                         case STATEMENT_WHILE:
4871                                         case STATEMENT_DO_WHILE:
4872                                         case STATEMENT_FOR:
4873                                                 last = parent;
4874                                                 next = parent->base.next;
4875                                                 goto found_break_parent;
4876
4877                                         default: break;
4878                                 }
4879                         }
4880 found_break_parent:
4881                         break;
4882
4883                 case STATEMENT_COMPUTED_GOTO: {
4884                         if (!expression_returns(stmt->computed_goto.expression))
4885                                 return;
4886
4887                         statement_t *parent = stmt->base.parent;
4888                         if (parent == NULL) /* top level goto */
4889                                 return;
4890                         next = parent;
4891                         break;
4892                 }
4893
4894                 case STATEMENT_GOTO:
4895                         next = stmt->gotos.label->statement;
4896                         if (next == NULL) /* missing label */
4897                                 return;
4898                         break;
4899
4900                 case STATEMENT_LABEL:
4901                         next = stmt->label.statement;
4902                         break;
4903
4904                 case STATEMENT_CASE_LABEL:
4905                         next = stmt->case_label.statement;
4906                         break;
4907
4908                 case STATEMENT_WHILE: {
4909                         while_statement_t const *const whiles = &stmt->whiles;
4910                         expression_t      const *const cond   = whiles->condition;
4911
4912                         if (!expression_returns(cond))
4913                                 return;
4914
4915                         int const val = determine_truth(cond);
4916
4917                         if (val >= 0)
4918                                 check_reachable(whiles->body);
4919
4920                         if (val > 0)
4921                                 return;
4922
4923                         next = stmt->base.next;
4924                         break;
4925                 }
4926
4927                 case STATEMENT_DO_WHILE:
4928                         next = stmt->do_while.body;
4929                         break;
4930
4931                 case STATEMENT_FOR: {
4932                         for_statement_t *const fors = &stmt->fors;
4933
4934                         if (fors->condition_reachable)
4935                                 return;
4936                         fors->condition_reachable = true;
4937
4938                         expression_t const *const cond = fors->condition;
4939
4940                         int val;
4941                         if (cond == NULL) {
4942                                 val = 1;
4943                         } else if (expression_returns(cond)) {
4944                                 val = determine_truth(cond);
4945                         } else {
4946                                 return;
4947                         }
4948
4949                         if (val >= 0)
4950                                 check_reachable(fors->body);
4951
4952                         if (val > 0)
4953                                 return;
4954
4955                         next = stmt->base.next;
4956                         break;
4957                 }
4958
4959                 case STATEMENT_MS_TRY: {
4960                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4961                         check_reachable(ms_try->try_statement);
4962                         next = ms_try->final_statement;
4963                         break;
4964                 }
4965
4966                 case STATEMENT_LEAVE: {
4967                         statement_t *parent = stmt;
4968                         for (;;) {
4969                                 parent = parent->base.parent;
4970                                 if (parent == NULL) /* __leave not within __try */
4971                                         return;
4972
4973                                 if (parent->kind == STATEMENT_MS_TRY) {
4974                                         last = parent;
4975                                         next = parent->ms_try.final_statement;
4976                                         break;
4977                                 }
4978                         }
4979                         break;
4980                 }
4981
4982                 default:
4983                         panic("invalid statement kind");
4984         }
4985
4986         while (next == NULL) {
4987                 next = last->base.parent;
4988                 if (next == NULL) {
4989                         noreturn_candidate = false;
4990
4991                         type_t *const type = skip_typeref(current_function->base.type);
4992                         assert(is_type_function(type));
4993                         type_t *const ret  = skip_typeref(type->function.return_type);
4994                         if (!is_type_void(ret) &&
4995                             is_type_valid(ret) &&
4996                             !is_main(current_entity)) {
4997                                 source_position_t const *const pos = &stmt->base.source_position;
4998                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4999                         }
5000                         return;
5001                 }
5002
5003                 switch (next->kind) {
5004                         case STATEMENT_ERROR:
5005                         case STATEMENT_EMPTY:
5006                         case STATEMENT_DECLARATION:
5007                         case STATEMENT_EXPRESSION:
5008                         case STATEMENT_ASM:
5009                         case STATEMENT_RETURN:
5010                         case STATEMENT_CONTINUE:
5011                         case STATEMENT_BREAK:
5012                         case STATEMENT_COMPUTED_GOTO:
5013                         case STATEMENT_GOTO:
5014                         case STATEMENT_LEAVE:
5015                                 panic("invalid control flow in function");
5016
5017                         case STATEMENT_COMPOUND:
5018                                 if (next->compound.stmt_expr) {
5019                                         reaches_end = true;
5020                                         return;
5021                                 }
5022                                 /* FALLTHROUGH */
5023                         case STATEMENT_IF:
5024                         case STATEMENT_SWITCH:
5025                         case STATEMENT_LABEL:
5026                         case STATEMENT_CASE_LABEL:
5027                                 last = next;
5028                                 next = next->base.next;
5029                                 break;
5030
5031                         case STATEMENT_WHILE: {
5032 continue_while:
5033                                 if (next->base.reachable)
5034                                         return;
5035                                 next->base.reachable = true;
5036
5037                                 while_statement_t const *const whiles = &next->whiles;
5038                                 expression_t      const *const cond   = whiles->condition;
5039
5040                                 if (!expression_returns(cond))
5041                                         return;
5042
5043                                 int const val = determine_truth(cond);
5044
5045                                 if (val >= 0)
5046                                         check_reachable(whiles->body);
5047
5048                                 if (val > 0)
5049                                         return;
5050
5051                                 last = next;
5052                                 next = next->base.next;
5053                                 break;
5054                         }
5055
5056                         case STATEMENT_DO_WHILE: {
5057 continue_do_while:
5058                                 if (next->base.reachable)
5059                                         return;
5060                                 next->base.reachable = true;
5061
5062                                 do_while_statement_t const *const dw   = &next->do_while;
5063                                 expression_t         const *const cond = dw->condition;
5064
5065                                 if (!expression_returns(cond))
5066                                         return;
5067
5068                                 int const val = determine_truth(cond);
5069
5070                                 if (val >= 0)
5071                                         check_reachable(dw->body);
5072
5073                                 if (val > 0)
5074                                         return;
5075
5076                                 last = next;
5077                                 next = next->base.next;
5078                                 break;
5079                         }
5080
5081                         case STATEMENT_FOR: {
5082 continue_for:;
5083                                 for_statement_t *const fors = &next->fors;
5084
5085                                 fors->step_reachable = true;
5086
5087                                 if (fors->condition_reachable)
5088                                         return;
5089                                 fors->condition_reachable = true;
5090
5091                                 expression_t const *const cond = fors->condition;
5092
5093                                 int val;
5094                                 if (cond == NULL) {
5095                                         val = 1;
5096                                 } else if (expression_returns(cond)) {
5097                                         val = determine_truth(cond);
5098                                 } else {
5099                                         return;
5100                                 }
5101
5102                                 if (val >= 0)
5103                                         check_reachable(fors->body);
5104
5105                                 if (val > 0)
5106                                         return;
5107
5108                                 last = next;
5109                                 next = next->base.next;
5110                                 break;
5111                         }
5112
5113                         case STATEMENT_MS_TRY:
5114                                 last = next;
5115                                 next = next->ms_try.final_statement;
5116                                 break;
5117                 }
5118         }
5119
5120         check_reachable(next);
5121 }
5122
5123 static void check_unreachable(statement_t* const stmt, void *const env)
5124 {
5125         (void)env;
5126
5127         switch (stmt->kind) {
5128                 case STATEMENT_DO_WHILE:
5129                         if (!stmt->base.reachable) {
5130                                 expression_t const *const cond = stmt->do_while.condition;
5131                                 if (determine_truth(cond) >= 0) {
5132                                         source_position_t const *const pos = &cond->base.source_position;
5133                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5134                                 }
5135                         }
5136                         return;
5137
5138                 case STATEMENT_FOR: {
5139                         for_statement_t const* const fors = &stmt->fors;
5140
5141                         // if init and step are unreachable, cond is unreachable, too
5142                         if (!stmt->base.reachable && !fors->step_reachable) {
5143                                 goto warn_unreachable;
5144                         } else {
5145                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5146                                         source_position_t const *const pos = &fors->initialisation->base.source_position;
5147                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5148                                 }
5149
5150                                 if (!fors->condition_reachable && fors->condition != NULL) {
5151                                         source_position_t const *const pos = &fors->condition->base.source_position;
5152                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5153                                 }
5154
5155                                 if (!fors->step_reachable && fors->step != NULL) {
5156                                         source_position_t const *const pos = &fors->step->base.source_position;
5157                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5158                                 }
5159                         }
5160                         return;
5161                 }
5162
5163                 case STATEMENT_COMPOUND:
5164                         if (stmt->compound.statements != NULL)
5165                                 return;
5166                         goto warn_unreachable;
5167
5168                 case STATEMENT_DECLARATION: {
5169                         /* Only warn if there is at least one declarator with an initializer.
5170                          * This typically occurs in switch statements. */
5171                         declaration_statement_t const *const decl = &stmt->declaration;
5172                         entity_t                const *      ent  = decl->declarations_begin;
5173                         entity_t                const *const last = decl->declarations_end;
5174                         if (ent != NULL) {
5175                                 for (;; ent = ent->base.next) {
5176                                         if (ent->kind                 == ENTITY_VARIABLE &&
5177                                                         ent->variable.initializer != NULL) {
5178                                                 goto warn_unreachable;
5179                                         }
5180                                         if (ent == last)
5181                                                 return;
5182                                 }
5183                         }
5184                 }
5185
5186                 default:
5187 warn_unreachable:
5188                         if (!stmt->base.reachable) {
5189                                 source_position_t const *const pos = &stmt->base.source_position;
5190                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5191                         }
5192                         return;
5193         }
5194 }
5195
5196 static bool is_main(entity_t *entity)
5197 {
5198         static symbol_t *sym_main = NULL;
5199         if (sym_main == NULL) {
5200                 sym_main = symbol_table_insert("main");
5201         }
5202
5203         if (entity->base.symbol != sym_main)
5204                 return false;
5205         /* must be in outermost scope */
5206         if (entity->base.parent_scope != file_scope)
5207                 return false;
5208
5209         return true;
5210 }
5211
5212 static void prepare_main_collect2(entity_t*);
5213
5214 static void parse_external_declaration(void)
5215 {
5216         /* function-definitions and declarations both start with declaration
5217          * specifiers */
5218         add_anchor_token(';');
5219         declaration_specifiers_t specifiers;
5220         parse_declaration_specifiers(&specifiers);
5221         rem_anchor_token(';');
5222
5223         /* must be a declaration */
5224         if (token.kind == ';') {
5225                 parse_anonymous_declaration_rest(&specifiers);
5226                 return;
5227         }
5228
5229         add_anchor_token(',');
5230         add_anchor_token('=');
5231         add_anchor_token(';');
5232         add_anchor_token('{');
5233
5234         /* declarator is common to both function-definitions and declarations */
5235         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5236
5237         rem_anchor_token('{');
5238         rem_anchor_token(';');
5239         rem_anchor_token('=');
5240         rem_anchor_token(',');
5241
5242         /* must be a declaration */
5243         switch (token.kind) {
5244                 case ',':
5245                 case ';':
5246                 case '=':
5247                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5248                                         DECL_FLAGS_NONE);
5249                         return;
5250         }
5251
5252         /* must be a function definition */
5253         parse_kr_declaration_list(ndeclaration);
5254
5255         if (token.kind != '{') {
5256                 parse_error_expected("while parsing function definition", '{', NULL);
5257                 eat_until_matching_token(';');
5258                 return;
5259         }
5260
5261         assert(is_declaration(ndeclaration));
5262         type_t *const orig_type = ndeclaration->declaration.type;
5263         type_t *      type      = skip_typeref(orig_type);
5264
5265         if (!is_type_function(type)) {
5266                 if (is_type_valid(type)) {
5267                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5268                 }
5269                 eat_block();
5270                 return;
5271         }
5272
5273         source_position_t const *const pos = &ndeclaration->base.source_position;
5274         if (is_typeref(orig_type)) {
5275                 /* §6.9.1:2 */
5276                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5277         }
5278
5279         if (is_type_compound(skip_typeref(type->function.return_type))) {
5280                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5281         }
5282         if (type->function.unspecified_parameters) {
5283                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5284         } else {
5285                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5286         }
5287
5288         /* §6.7.5.3:14 a function definition with () means no
5289          * parameters (and not unspecified parameters) */
5290         if (type->function.unspecified_parameters &&
5291                         type->function.parameters == NULL) {
5292                 type_t *copy                          = duplicate_type(type);
5293                 copy->function.unspecified_parameters = false;
5294                 type                                  = identify_new_type(copy);
5295
5296                 ndeclaration->declaration.type = type;
5297         }
5298
5299         entity_t *const entity = record_entity(ndeclaration, true);
5300         assert(entity->kind == ENTITY_FUNCTION);
5301         assert(ndeclaration->kind == ENTITY_FUNCTION);
5302
5303         function_t *const function = &entity->function;
5304         if (ndeclaration != entity) {
5305                 function->parameters = ndeclaration->function.parameters;
5306         }
5307
5308         PUSH_SCOPE(&function->parameters);
5309
5310         entity_t *parameter = function->parameters.entities;
5311         for (; parameter != NULL; parameter = parameter->base.next) {
5312                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5313                         parameter->base.parent_scope = current_scope;
5314                 }
5315                 assert(parameter->base.parent_scope == NULL
5316                                 || parameter->base.parent_scope == current_scope);
5317                 parameter->base.parent_scope = current_scope;
5318                 if (parameter->base.symbol == NULL) {
5319                         errorf(&parameter->base.source_position, "parameter name omitted");
5320                         continue;
5321                 }
5322                 environment_push(parameter);
5323         }
5324
5325         if (function->statement != NULL) {
5326                 parser_error_multiple_definition(entity, HERE);
5327                 eat_block();
5328         } else {
5329                 /* parse function body */
5330                 int         label_stack_top      = label_top();
5331                 function_t *old_current_function = current_function;
5332                 current_function                 = function;
5333                 PUSH_CURRENT_ENTITY(entity);
5334                 PUSH_PARENT(NULL);
5335
5336                 goto_first   = NULL;
5337                 goto_anchor  = &goto_first;
5338                 label_first  = NULL;
5339                 label_anchor = &label_first;
5340
5341                 statement_t *const body = parse_compound_statement(false);
5342                 function->statement = body;
5343                 first_err = true;
5344                 check_labels();
5345                 check_declarations();
5346                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5347                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5348                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5349                         noreturn_candidate = true;
5350                         check_reachable(body);
5351                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5352                                 walk_statements(body, check_unreachable, NULL);
5353                         if (noreturn_candidate &&
5354                             !(function->base.modifiers & DM_NORETURN)) {
5355                                 source_position_t const *const pos = &body->base.source_position;
5356                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5357                         }
5358                 }
5359
5360                 if (is_main(entity)) {
5361                         /* Force main to C linkage. */
5362                         type_t *const type = entity->declaration.type;
5363                         assert(is_type_function(type));
5364                         if (type->function.linkage != LINKAGE_C) {
5365                                 type_t *new_type           = duplicate_type(type);
5366                                 new_type->function.linkage = LINKAGE_C;
5367                                 entity->declaration.type   = identify_new_type(new_type);
5368                         }
5369
5370                         if (enable_main_collect2_hack)
5371                                 prepare_main_collect2(entity);
5372                 }
5373
5374                 POP_CURRENT_ENTITY();
5375                 POP_PARENT();
5376                 assert(current_function == function);
5377                 current_function = old_current_function;
5378                 label_pop_to(label_stack_top);
5379         }
5380
5381         POP_SCOPE();
5382 }
5383
5384 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5385 {
5386         entity_t *iter = compound->members.entities;
5387         for (; iter != NULL; iter = iter->base.next) {
5388                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5389                         continue;
5390
5391                 if (iter->base.symbol == symbol) {
5392                         return iter;
5393                 } else if (iter->base.symbol == NULL) {
5394                         /* search in anonymous structs and unions */
5395                         type_t *type = skip_typeref(iter->declaration.type);
5396                         if (is_type_compound(type)) {
5397                                 if (find_compound_entry(type->compound.compound, symbol)
5398                                                 != NULL)
5399                                         return iter;
5400                         }
5401                         continue;
5402                 }
5403         }
5404
5405         return NULL;
5406 }
5407
5408 static void check_deprecated(const source_position_t *source_position,
5409                              const entity_t *entity)
5410 {
5411         if (!is_declaration(entity))
5412                 return;
5413         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5414                 return;
5415
5416         source_position_t const *const epos = &entity->base.source_position;
5417         char              const *const msg  = get_deprecated_string(entity->declaration.attributes);
5418         if (msg != NULL) {
5419                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5420         } else {
5421                 warningf(WARN_DEPRECATED_DECLARATIONS, source_position, "'%N' is deprecated (declared %P)", entity, epos);
5422         }
5423 }
5424
5425
5426 static expression_t *create_select(const source_position_t *pos,
5427                                    expression_t *addr,
5428                                    type_qualifiers_t qualifiers,
5429                                                                    entity_t *entry)
5430 {
5431         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5432
5433         check_deprecated(pos, entry);
5434
5435         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5436         select->select.compound       = addr;
5437         select->select.compound_entry = entry;
5438
5439         type_t *entry_type = entry->declaration.type;
5440         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5441
5442         /* bitfields need special treatment */
5443         if (entry->compound_member.bitfield) {
5444                 unsigned bit_size = entry->compound_member.bit_size;
5445                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5446                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5447                         res_type = type_int;
5448                 }
5449         }
5450
5451         /* we always do the auto-type conversions; the & and sizeof parser contains
5452          * code to revert this! */
5453         select->base.type = automatic_type_conversion(res_type);
5454
5455
5456         return select;
5457 }
5458
5459 /**
5460  * Find entry with symbol in compound. Search anonymous structs and unions and
5461  * creates implicit select expressions for them.
5462  * Returns the adress for the innermost compound.
5463  */
5464 static expression_t *find_create_select(const source_position_t *pos,
5465                                         expression_t *addr,
5466                                         type_qualifiers_t qualifiers,
5467                                         compound_t *compound, symbol_t *symbol)
5468 {
5469         entity_t *iter = compound->members.entities;
5470         for (; iter != NULL; iter = iter->base.next) {
5471                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5472                         continue;
5473
5474                 symbol_t *iter_symbol = iter->base.symbol;
5475                 if (iter_symbol == NULL) {
5476                         type_t *type = iter->declaration.type;
5477                         if (type->kind != TYPE_COMPOUND_STRUCT
5478                                         && type->kind != TYPE_COMPOUND_UNION)
5479                                 continue;
5480
5481                         compound_t *sub_compound = type->compound.compound;
5482
5483                         if (find_compound_entry(sub_compound, symbol) == NULL)
5484                                 continue;
5485
5486                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5487                         sub_addr->base.source_position = *pos;
5488                         sub_addr->base.implicit        = true;
5489                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5490                                                   symbol);
5491                 }
5492
5493                 if (iter_symbol == symbol) {
5494                         return create_select(pos, addr, qualifiers, iter);
5495                 }
5496         }
5497
5498         return NULL;
5499 }
5500
5501 static void parse_bitfield_member(entity_t *entity)
5502 {
5503         eat(':');
5504
5505         expression_t *size = parse_constant_expression();
5506         long          size_long;
5507
5508         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5509         type_t *type = entity->declaration.type;
5510         if (!is_type_integer(skip_typeref(type))) {
5511                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5512                            type);
5513         }
5514
5515         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5516                 /* error already reported by parse_constant_expression */
5517                 size_long = get_type_size(type) * 8;
5518         } else {
5519                 size_long = fold_constant_to_int(size);
5520
5521                 const symbol_t *symbol = entity->base.symbol;
5522                 const symbol_t *user_symbol
5523                         = symbol == NULL ? sym_anonymous : symbol;
5524                 unsigned bit_size = get_type_size(type) * 8;
5525                 if (size_long < 0) {
5526                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5527                 } else if (size_long == 0 && symbol != NULL) {
5528                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5529                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5530                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5531                                    user_symbol);
5532                 } else {
5533                         /* hope that people don't invent crazy types with more bits
5534                          * than our struct can hold */
5535                         assert(size_long <
5536                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5537                 }
5538         }
5539
5540         entity->compound_member.bitfield = true;
5541         entity->compound_member.bit_size = (unsigned char)size_long;
5542 }
5543
5544 static void parse_compound_declarators(compound_t *compound,
5545                 const declaration_specifiers_t *specifiers)
5546 {
5547         add_anchor_token(';');
5548         add_anchor_token(',');
5549         do {
5550                 entity_t *entity;
5551
5552                 if (token.kind == ':') {
5553                         /* anonymous bitfield */
5554                         type_t *type = specifiers->type;
5555                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5556                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5557                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5558                         entity->declaration.type                   = type;
5559
5560                         parse_bitfield_member(entity);
5561
5562                         attribute_t  *attributes = parse_attributes(NULL);
5563                         attribute_t **anchor     = &attributes;
5564                         while (*anchor != NULL)
5565                                 anchor = &(*anchor)->next;
5566                         *anchor = specifiers->attributes;
5567                         if (attributes != NULL) {
5568                                 handle_entity_attributes(attributes, entity);
5569                         }
5570                         entity->declaration.attributes = attributes;
5571
5572                         append_entity(&compound->members, entity);
5573                 } else {
5574                         entity = parse_declarator(specifiers,
5575                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5576                         source_position_t const *const pos = &entity->base.source_position;
5577                         if (entity->kind == ENTITY_TYPEDEF) {
5578                                 errorf(pos, "typedef not allowed as compound member");
5579                         } else {
5580                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5581
5582                                 /* make sure we don't define a symbol multiple times */
5583                                 symbol_t *symbol = entity->base.symbol;
5584                                 if (symbol != NULL) {
5585                                         entity_t *prev = find_compound_entry(compound, symbol);
5586                                         if (prev != NULL) {
5587                                                 source_position_t const *const ppos = &prev->base.source_position;
5588                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5589                                         }
5590                                 }
5591
5592                                 if (token.kind == ':') {
5593                                         parse_bitfield_member(entity);
5594
5595                                         attribute_t *attributes = parse_attributes(NULL);
5596                                         handle_entity_attributes(attributes, entity);
5597                                 } else {
5598                                         type_t *orig_type = entity->declaration.type;
5599                                         type_t *type      = skip_typeref(orig_type);
5600                                         if (is_type_function(type)) {
5601                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5602                                         } else if (is_type_incomplete(type)) {
5603                                                 /* §6.7.2.1:16 flexible array member */
5604                                                 if (!is_type_array(type)       ||
5605                                                                 token.kind          != ';' ||
5606                                                                 look_ahead(1)->kind != '}') {
5607                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5608                                                 } else if (compound->members.entities == NULL) {
5609                                                         errorf(pos, "flexible array member in otherwise empty struct");
5610                                                 }
5611                                         }
5612                                 }
5613
5614                                 append_entity(&compound->members, entity);
5615                         }
5616                 }
5617         } while (next_if(','));
5618         rem_anchor_token(',');
5619         rem_anchor_token(';');
5620         expect(';');
5621
5622         anonymous_entity = NULL;
5623 }
5624
5625 static void parse_compound_type_entries(compound_t *compound)
5626 {
5627         eat('{');
5628         add_anchor_token('}');
5629
5630         for (;;) {
5631                 switch (token.kind) {
5632                         DECLARATION_START
5633                         case T___extension__:
5634                         case T_IDENTIFIER: {
5635                                 PUSH_EXTENSION();
5636                                 declaration_specifiers_t specifiers;
5637                                 parse_declaration_specifiers(&specifiers);
5638                                 parse_compound_declarators(compound, &specifiers);
5639                                 POP_EXTENSION();
5640                                 break;
5641                         }
5642
5643                         default:
5644                                 rem_anchor_token('}');
5645                                 expect('}');
5646                                 /* §6.7.2.1:7 */
5647                                 compound->complete = true;
5648                                 return;
5649                 }
5650         }
5651 }
5652
5653 static type_t *parse_typename(void)
5654 {
5655         declaration_specifiers_t specifiers;
5656         parse_declaration_specifiers(&specifiers);
5657         if (specifiers.storage_class != STORAGE_CLASS_NONE
5658                         || specifiers.thread_local) {
5659                 /* TODO: improve error message, user does probably not know what a
5660                  * storage class is...
5661                  */
5662                 errorf(&specifiers.source_position, "typename must not have a storage class");
5663         }
5664
5665         type_t *result = parse_abstract_declarator(specifiers.type);
5666
5667         return result;
5668 }
5669
5670
5671
5672
5673 typedef expression_t* (*parse_expression_function)(void);
5674 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5675
5676 typedef struct expression_parser_function_t expression_parser_function_t;
5677 struct expression_parser_function_t {
5678         parse_expression_function        parser;
5679         precedence_t                     infix_precedence;
5680         parse_expression_infix_function  infix_parser;
5681 };
5682
5683 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5684
5685 static type_t *get_string_type(void)
5686 {
5687         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_char_ptr : type_char_ptr;
5688 }
5689
5690 static type_t *get_wide_string_type(void)
5691 {
5692         return is_warn_on(WARN_WRITE_STRINGS) ? type_const_wchar_t_ptr : type_wchar_t_ptr;
5693 }
5694
5695 /**
5696  * Parse a string constant.
5697  */
5698 static expression_t *parse_string_literal(void)
5699 {
5700         source_position_t begin   = *HERE;
5701         string_t          res     = token.string.string;
5702         bool              is_wide = (token.kind == T_WIDE_STRING_LITERAL);
5703
5704         next_token();
5705         while (token.kind == T_STRING_LITERAL
5706                         || token.kind == T_WIDE_STRING_LITERAL) {
5707                 warn_string_concat(HERE);
5708                 res = concat_strings(&res, &token.string.string);
5709                 next_token();
5710                 is_wide |= token.kind == T_WIDE_STRING_LITERAL;
5711         }
5712
5713         expression_t *literal;
5714         if (is_wide) {
5715                 literal = allocate_expression_zero(EXPR_WIDE_STRING_LITERAL);
5716                 literal->base.type = get_wide_string_type();
5717         } else {
5718                 literal = allocate_expression_zero(EXPR_STRING_LITERAL);
5719                 literal->base.type = get_string_type();
5720         }
5721         literal->base.source_position = begin;
5722         literal->literal.value        = res;
5723
5724         return literal;
5725 }
5726
5727 /**
5728  * Parse a boolean constant.
5729  */
5730 static expression_t *parse_boolean_literal(bool value)
5731 {
5732         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5733         literal->base.type           = type_bool;
5734         literal->literal.value.begin = value ? "true" : "false";
5735         literal->literal.value.size  = value ? 4 : 5;
5736
5737         next_token();
5738         return literal;
5739 }
5740
5741 static void warn_traditional_suffix(void)
5742 {
5743         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%S' suffix",
5744                  &token.number.suffix);
5745 }
5746
5747 static void check_integer_suffix(void)
5748 {
5749         const string_t *suffix = &token.number.suffix;
5750         if (suffix->size == 0)
5751                 return;
5752
5753         bool not_traditional = false;
5754         const char *c = suffix->begin;
5755         if (*c == 'l' || *c == 'L') {
5756                 ++c;
5757                 if (*c == *(c-1)) {
5758                         not_traditional = true;
5759                         ++c;
5760                         if (*c == 'u' || *c == 'U') {
5761                                 ++c;
5762                         }
5763                 } else if (*c == 'u' || *c == 'U') {
5764                         not_traditional = true;
5765                         ++c;
5766                 }
5767         } else if (*c == 'u' || *c == 'U') {
5768                 not_traditional = true;
5769                 ++c;
5770                 if (*c == 'l' || *c == 'L') {
5771                         ++c;
5772                         if (*c == *(c-1)) {
5773                                 ++c;
5774                         }
5775                 }
5776         }
5777         if (*c != '\0') {
5778                 errorf(HERE, "invalid suffix '%S' on integer constant", suffix);
5779         } else if (not_traditional) {
5780                 warn_traditional_suffix();
5781         }
5782 }
5783
5784 static type_t *check_floatingpoint_suffix(void)
5785 {
5786         const string_t *suffix = &token.number.suffix;
5787         type_t         *type   = type_double;
5788         if (suffix->size == 0)
5789                 return type;
5790
5791         bool not_traditional = false;
5792         const char *c = suffix->begin;
5793         if (*c == 'f' || *c == 'F') {
5794                 ++c;
5795                 type = type_float;
5796         } else if (*c == 'l' || *c == 'L') {
5797                 ++c;
5798                 type = type_long_double;
5799         }
5800         if (*c != '\0') {
5801                 errorf(HERE, "invalid suffix '%S' on floatingpoint constant", suffix);
5802         } else if (not_traditional) {
5803                 warn_traditional_suffix();
5804         }
5805
5806         return type;
5807 }
5808
5809 /**
5810  * Parse an integer constant.
5811  */
5812 static expression_t *parse_number_literal(void)
5813 {
5814         expression_kind_t  kind;
5815         type_t            *type;
5816
5817         switch (token.kind) {
5818         case T_INTEGER:
5819                 kind = EXPR_LITERAL_INTEGER;
5820                 check_integer_suffix();
5821                 type = type_int;
5822                 break;
5823
5824         case T_FLOATINGPOINT:
5825                 kind = EXPR_LITERAL_FLOATINGPOINT;
5826                 type = check_floatingpoint_suffix();
5827                 break;
5828
5829         default:
5830                 panic("unexpected token type in parse_number_literal");
5831         }
5832
5833         expression_t *literal = allocate_expression_zero(kind);
5834         literal->base.type      = type;
5835         literal->literal.value  = token.number.number;
5836         literal->literal.suffix = token.number.suffix;
5837         next_token();
5838
5839         /* integer type depends on the size of the number and the size
5840          * representable by the types. The backend/codegeneration has to determine
5841          * that
5842          */
5843         determine_literal_type(&literal->literal);
5844         return literal;
5845 }
5846
5847 /**
5848  * Parse a character constant.
5849  */
5850 static expression_t *parse_character_constant(void)
5851 {
5852         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5853         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5854         literal->literal.value = token.string.string;
5855
5856         size_t len = literal->literal.value.size;
5857         if (len > 1) {
5858                 if (!GNU_MODE && !(c_mode & _C99)) {
5859                         errorf(HERE, "more than 1 character in character constant");
5860                 } else {
5861                         literal->base.type = type_int;
5862                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5863                 }
5864         }
5865
5866         next_token();
5867         return literal;
5868 }
5869
5870 /**
5871  * Parse a wide character constant.
5872  */
5873 static expression_t *parse_wide_character_constant(void)
5874 {
5875         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5876         literal->base.type     = type_int;
5877         literal->literal.value = token.string.string;
5878
5879         size_t len = wstrlen(&literal->literal.value);
5880         if (len > 1) {
5881                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5882         }
5883
5884         next_token();
5885         return literal;
5886 }
5887
5888 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5889 {
5890         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5891         ntype->function.return_type            = type_int;
5892         ntype->function.unspecified_parameters = true;
5893         ntype->function.linkage                = LINKAGE_C;
5894         type_t *type                           = identify_new_type(ntype);
5895
5896         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5897         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5898         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5899         entity->declaration.type                   = type;
5900         entity->declaration.implicit               = true;
5901
5902         if (current_scope != NULL)
5903                 record_entity(entity, false);
5904
5905         return entity;
5906 }
5907
5908 /**
5909  * Performs automatic type cast as described in §6.3.2.1.
5910  *
5911  * @param orig_type  the original type
5912  */
5913 static type_t *automatic_type_conversion(type_t *orig_type)
5914 {
5915         type_t *type = skip_typeref(orig_type);
5916         if (is_type_array(type)) {
5917                 array_type_t *array_type   = &type->array;
5918                 type_t       *element_type = array_type->element_type;
5919                 unsigned      qualifiers   = array_type->base.qualifiers;
5920
5921                 return make_pointer_type(element_type, qualifiers);
5922         }
5923
5924         if (is_type_function(type)) {
5925                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5926         }
5927
5928         return orig_type;
5929 }
5930
5931 /**
5932  * reverts the automatic casts of array to pointer types and function
5933  * to function-pointer types as defined §6.3.2.1
5934  */
5935 type_t *revert_automatic_type_conversion(const expression_t *expression)
5936 {
5937         switch (expression->kind) {
5938         case EXPR_REFERENCE: {
5939                 entity_t *entity = expression->reference.entity;
5940                 if (is_declaration(entity)) {
5941                         return entity->declaration.type;
5942                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5943                         return entity->enum_value.enum_type;
5944                 } else {
5945                         panic("no declaration or enum in reference");
5946                 }
5947         }
5948
5949         case EXPR_SELECT: {
5950                 entity_t *entity = expression->select.compound_entry;
5951                 assert(is_declaration(entity));
5952                 type_t   *type   = entity->declaration.type;
5953                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5954         }
5955
5956         case EXPR_UNARY_DEREFERENCE: {
5957                 const expression_t *const value = expression->unary.value;
5958                 type_t             *const type  = skip_typeref(value->base.type);
5959                 if (!is_type_pointer(type))
5960                         return type_error_type;
5961                 return type->pointer.points_to;
5962         }
5963
5964         case EXPR_ARRAY_ACCESS: {
5965                 const expression_t *array_ref = expression->array_access.array_ref;
5966                 type_t             *type_left = skip_typeref(array_ref->base.type);
5967                 if (!is_type_pointer(type_left))
5968                         return type_error_type;
5969                 return type_left->pointer.points_to;
5970         }
5971
5972         case EXPR_STRING_LITERAL: {
5973                 size_t size = expression->string_literal.value.size;
5974                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
5975         }
5976
5977         case EXPR_WIDE_STRING_LITERAL: {
5978                 size_t size = wstrlen(&expression->string_literal.value);
5979                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
5980         }
5981
5982         case EXPR_COMPOUND_LITERAL:
5983                 return expression->compound_literal.type;
5984
5985         default:
5986                 break;
5987         }
5988         return expression->base.type;
5989 }
5990
5991 /**
5992  * Find an entity matching a symbol in a scope.
5993  * Uses current scope if scope is NULL
5994  */
5995 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5996                                namespace_tag_t namespc)
5997 {
5998         if (scope == NULL) {
5999                 return get_entity(symbol, namespc);
6000         }
6001
6002         /* we should optimize here, if scope grows above a certain size we should
6003            construct a hashmap here... */
6004         entity_t *entity = scope->entities;
6005         for ( ; entity != NULL; entity = entity->base.next) {
6006                 if (entity->base.symbol == symbol
6007                     && (namespace_tag_t)entity->base.namespc == namespc)
6008                         break;
6009         }
6010
6011         return entity;
6012 }
6013
6014 static entity_t *parse_qualified_identifier(void)
6015 {
6016         /* namespace containing the symbol */
6017         symbol_t          *symbol;
6018         source_position_t  pos;
6019         const scope_t     *lookup_scope = NULL;
6020
6021         if (next_if(T_COLONCOLON))
6022                 lookup_scope = &unit->scope;
6023
6024         entity_t *entity;
6025         while (true) {
6026                 symbol = expect_identifier("while parsing identifier", &pos);
6027                 if (!symbol)
6028                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6029
6030                 /* lookup entity */
6031                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6032
6033                 if (!next_if(T_COLONCOLON))
6034                         break;
6035
6036                 switch (entity->kind) {
6037                 case ENTITY_NAMESPACE:
6038                         lookup_scope = &entity->namespacee.members;
6039                         break;
6040                 case ENTITY_STRUCT:
6041                 case ENTITY_UNION:
6042                 case ENTITY_CLASS:
6043                         lookup_scope = &entity->compound.members;
6044                         break;
6045                 default:
6046                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6047                                symbol, get_entity_kind_name(entity->kind));
6048
6049                         /* skip further qualifications */
6050                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6051
6052                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6053                 }
6054         }
6055
6056         if (entity == NULL) {
6057                 if (!strict_mode && token.kind == '(') {
6058                         /* an implicitly declared function */
6059                         entity = create_implicit_function(symbol, &pos);
6060                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6061                 } else {
6062                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6063                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6064                 }
6065         }
6066
6067         return entity;
6068 }
6069
6070 static expression_t *parse_reference(void)
6071 {
6072         source_position_t const pos    = *HERE;
6073         entity_t         *const entity = parse_qualified_identifier();
6074
6075         type_t *orig_type;
6076         if (is_declaration(entity)) {
6077                 orig_type = entity->declaration.type;
6078         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6079                 orig_type = entity->enum_value.enum_type;
6080         } else {
6081                 panic("expected declaration or enum value in reference");
6082         }
6083
6084         /* we always do the auto-type conversions; the & and sizeof parser contains
6085          * code to revert this! */
6086         type_t *type = automatic_type_conversion(orig_type);
6087
6088         expression_kind_t kind = EXPR_REFERENCE;
6089         if (entity->kind == ENTITY_ENUM_VALUE)
6090                 kind = EXPR_ENUM_CONSTANT;
6091
6092         expression_t *expression         = allocate_expression_zero(kind);
6093         expression->base.source_position = pos;
6094         expression->base.type            = type;
6095         expression->reference.entity     = entity;
6096
6097         /* this declaration is used */
6098         if (is_declaration(entity)) {
6099                 entity->declaration.used = true;
6100         }
6101
6102         if (entity->base.parent_scope != file_scope
6103                 && (current_function != NULL
6104                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6105                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6106                 /* access of a variable from an outer function */
6107                 entity->variable.address_taken = true;
6108                 current_function->need_closure = true;
6109         }
6110
6111         check_deprecated(&pos, entity);
6112
6113         return expression;
6114 }
6115
6116 static bool semantic_cast(expression_t *cast)
6117 {
6118         expression_t            *expression      = cast->unary.value;
6119         type_t                  *orig_dest_type  = cast->base.type;
6120         type_t                  *orig_type_right = expression->base.type;
6121         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6122         type_t            const *src_type        = skip_typeref(orig_type_right);
6123         source_position_t const *pos             = &cast->base.source_position;
6124
6125         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6126         if (is_type_void(dst_type))
6127                 return true;
6128
6129         /* only integer and pointer can be casted to pointer */
6130         if (is_type_pointer(dst_type)  &&
6131             !is_type_pointer(src_type) &&
6132             !is_type_integer(src_type) &&
6133             is_type_valid(src_type)) {
6134                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6135                 return false;
6136         }
6137
6138         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6139                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6140                 return false;
6141         }
6142
6143         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6144                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6145                 return false;
6146         }
6147
6148         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6149                 type_t *src = skip_typeref(src_type->pointer.points_to);
6150                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6151                 unsigned missing_qualifiers =
6152                         src->base.qualifiers & ~dst->base.qualifiers;
6153                 if (missing_qualifiers != 0) {
6154                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6155                 }
6156         }
6157         return true;
6158 }
6159
6160 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6161 {
6162         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6163         expression->base.source_position = *pos;
6164
6165         parse_initializer_env_t env;
6166         env.type             = type;
6167         env.entity           = NULL;
6168         env.must_be_constant = false;
6169         initializer_t *initializer = parse_initializer(&env);
6170         type = env.type;
6171
6172         expression->compound_literal.initializer = initializer;
6173         expression->compound_literal.type        = type;
6174         expression->base.type                    = automatic_type_conversion(type);
6175
6176         return expression;
6177 }
6178
6179 /**
6180  * Parse a cast expression.
6181  */
6182 static expression_t *parse_cast(void)
6183 {
6184         source_position_t const pos = *HERE;
6185
6186         eat('(');
6187         add_anchor_token(')');
6188
6189         type_t *type = parse_typename();
6190
6191         rem_anchor_token(')');
6192         expect(')');
6193
6194         if (token.kind == '{') {
6195                 return parse_compound_literal(&pos, type);
6196         }
6197
6198         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6199         cast->base.source_position = pos;
6200
6201         expression_t *value = parse_subexpression(PREC_CAST);
6202         cast->base.type   = type;
6203         cast->unary.value = value;
6204
6205         if (! semantic_cast(cast)) {
6206                 /* TODO: record the error in the AST. else it is impossible to detect it */
6207         }
6208
6209         return cast;
6210 }
6211
6212 /**
6213  * Parse a statement expression.
6214  */
6215 static expression_t *parse_statement_expression(void)
6216 {
6217         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6218
6219         eat('(');
6220         add_anchor_token(')');
6221
6222         statement_t *statement          = parse_compound_statement(true);
6223         statement->compound.stmt_expr   = true;
6224         expression->statement.statement = statement;
6225
6226         /* find last statement and use its type */
6227         type_t *type = type_void;
6228         const statement_t *stmt = statement->compound.statements;
6229         if (stmt != NULL) {
6230                 while (stmt->base.next != NULL)
6231                         stmt = stmt->base.next;
6232
6233                 if (stmt->kind == STATEMENT_EXPRESSION) {
6234                         type = stmt->expression.expression->base.type;
6235                 }
6236         } else {
6237                 source_position_t const *const pos = &expression->base.source_position;
6238                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6239         }
6240         expression->base.type = type;
6241
6242         rem_anchor_token(')');
6243         expect(')');
6244         return expression;
6245 }
6246
6247 /**
6248  * Parse a parenthesized expression.
6249  */
6250 static expression_t *parse_parenthesized_expression(void)
6251 {
6252         token_t const* const la1 = look_ahead(1);
6253         switch (la1->kind) {
6254         case '{':
6255                 /* gcc extension: a statement expression */
6256                 return parse_statement_expression();
6257
6258         case T_IDENTIFIER:
6259                 if (is_typedef_symbol(la1->base.symbol)) {
6260         DECLARATION_START
6261                         return parse_cast();
6262                 }
6263         }
6264
6265         eat('(');
6266         add_anchor_token(')');
6267         expression_t *result = parse_expression();
6268         result->base.parenthesized = true;
6269         rem_anchor_token(')');
6270         expect(')');
6271
6272         return result;
6273 }
6274
6275 static expression_t *parse_function_keyword(void)
6276 {
6277         /* TODO */
6278
6279         if (current_function == NULL) {
6280                 errorf(HERE, "'__func__' used outside of a function");
6281         }
6282
6283         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6284         expression->base.type     = type_char_ptr;
6285         expression->funcname.kind = FUNCNAME_FUNCTION;
6286
6287         next_token();
6288
6289         return expression;
6290 }
6291
6292 static expression_t *parse_pretty_function_keyword(void)
6293 {
6294         if (current_function == NULL) {
6295                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6296         }
6297
6298         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6299         expression->base.type     = type_char_ptr;
6300         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6301
6302         eat(T___PRETTY_FUNCTION__);
6303
6304         return expression;
6305 }
6306
6307 static expression_t *parse_funcsig_keyword(void)
6308 {
6309         if (current_function == NULL) {
6310                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6311         }
6312
6313         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6314         expression->base.type     = type_char_ptr;
6315         expression->funcname.kind = FUNCNAME_FUNCSIG;
6316
6317         eat(T___FUNCSIG__);
6318
6319         return expression;
6320 }
6321
6322 static expression_t *parse_funcdname_keyword(void)
6323 {
6324         if (current_function == NULL) {
6325                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6326         }
6327
6328         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6329         expression->base.type     = type_char_ptr;
6330         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6331
6332         eat(T___FUNCDNAME__);
6333
6334         return expression;
6335 }
6336
6337 static designator_t *parse_designator(void)
6338 {
6339         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6340         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6341         if (!result->symbol)
6342                 return NULL;
6343
6344         designator_t *last_designator = result;
6345         while (true) {
6346                 if (next_if('.')) {
6347                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6348                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6349                         if (!designator->symbol)
6350                                 return NULL;
6351
6352                         last_designator->next = designator;
6353                         last_designator       = designator;
6354                         continue;
6355                 }
6356                 if (next_if('[')) {
6357                         add_anchor_token(']');
6358                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6359                         designator->source_position = *HERE;
6360                         designator->array_index     = parse_expression();
6361                         rem_anchor_token(']');
6362                         expect(']');
6363                         if (designator->array_index == NULL) {
6364                                 return NULL;
6365                         }
6366
6367                         last_designator->next = designator;
6368                         last_designator       = designator;
6369                         continue;
6370                 }
6371                 break;
6372         }
6373
6374         return result;
6375 }
6376
6377 /**
6378  * Parse the __builtin_offsetof() expression.
6379  */
6380 static expression_t *parse_offsetof(void)
6381 {
6382         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6383         expression->base.type    = type_size_t;
6384
6385         eat(T___builtin_offsetof);
6386
6387         expect('(');
6388         add_anchor_token(')');
6389         add_anchor_token(',');
6390         type_t *type = parse_typename();
6391         rem_anchor_token(',');
6392         expect(',');
6393         designator_t *designator = parse_designator();
6394         rem_anchor_token(')');
6395         expect(')');
6396
6397         expression->offsetofe.type       = type;
6398         expression->offsetofe.designator = designator;
6399
6400         type_path_t path;
6401         memset(&path, 0, sizeof(path));
6402         path.top_type = type;
6403         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6404
6405         descend_into_subtype(&path);
6406
6407         if (!walk_designator(&path, designator, true)) {
6408                 return create_error_expression();
6409         }
6410
6411         DEL_ARR_F(path.path);
6412
6413         return expression;
6414 }
6415
6416 static bool is_last_parameter(expression_t *const param)
6417 {
6418         if (param->kind == EXPR_REFERENCE) {
6419                 entity_t *const entity = param->reference.entity;
6420                 if (entity->kind == ENTITY_PARAMETER &&
6421                     !entity->base.next               &&
6422                     entity->base.parent_scope == &current_function->parameters) {
6423                         return true;
6424                 }
6425         }
6426
6427         if (!is_type_valid(skip_typeref(param->base.type)))
6428                 return true;
6429
6430         return false;
6431 }
6432
6433 /**
6434  * Parses a __builtin_va_start() expression.
6435  */
6436 static expression_t *parse_va_start(void)
6437 {
6438         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6439
6440         eat(T___builtin_va_start);
6441
6442         expect('(');
6443         add_anchor_token(')');
6444         add_anchor_token(',');
6445         expression->va_starte.ap = parse_assignment_expression();
6446         rem_anchor_token(',');
6447         expect(',');
6448         expression_t *const param = parse_assignment_expression();
6449         expression->va_starte.parameter = param;
6450         rem_anchor_token(')');
6451         expect(')');
6452
6453         if (!current_function) {
6454                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6455         } else if (!current_function->base.type->function.variadic) {
6456                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6457         } else if (!is_last_parameter(param)) {
6458                 errorf(&param->base.source_position, "second argument of 'va_start' must be last parameter of the current function");
6459         }
6460
6461         return expression;
6462 }
6463
6464 /**
6465  * Parses a __builtin_va_arg() expression.
6466  */
6467 static expression_t *parse_va_arg(void)
6468 {
6469         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6470
6471         eat(T___builtin_va_arg);
6472
6473         expect('(');
6474         add_anchor_token(')');
6475         add_anchor_token(',');
6476         call_argument_t ap;
6477         ap.expression = parse_assignment_expression();
6478         expression->va_arge.ap = ap.expression;
6479         check_call_argument(type_valist, &ap, 1);
6480
6481         rem_anchor_token(',');
6482         expect(',');
6483         expression->base.type = parse_typename();
6484         rem_anchor_token(')');
6485         expect(')');
6486
6487         return expression;
6488 }
6489
6490 /**
6491  * Parses a __builtin_va_copy() expression.
6492  */
6493 static expression_t *parse_va_copy(void)
6494 {
6495         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6496
6497         eat(T___builtin_va_copy);
6498
6499         expect('(');
6500         add_anchor_token(')');
6501         add_anchor_token(',');
6502         expression_t *dst = parse_assignment_expression();
6503         assign_error_t error = semantic_assign(type_valist, dst);
6504         report_assign_error(error, type_valist, dst, "call argument 1",
6505                             &dst->base.source_position);
6506         expression->va_copye.dst = dst;
6507
6508         rem_anchor_token(',');
6509         expect(',');
6510
6511         call_argument_t src;
6512         src.expression = parse_assignment_expression();
6513         check_call_argument(type_valist, &src, 2);
6514         expression->va_copye.src = src.expression;
6515         rem_anchor_token(')');
6516         expect(')');
6517
6518         return expression;
6519 }
6520
6521 /**
6522  * Parses a __builtin_constant_p() expression.
6523  */
6524 static expression_t *parse_builtin_constant(void)
6525 {
6526         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6527
6528         eat(T___builtin_constant_p);
6529
6530         expect('(');
6531         add_anchor_token(')');
6532         expression->builtin_constant.value = parse_assignment_expression();
6533         rem_anchor_token(')');
6534         expect(')');
6535         expression->base.type = type_int;
6536
6537         return expression;
6538 }
6539
6540 /**
6541  * Parses a __builtin_types_compatible_p() expression.
6542  */
6543 static expression_t *parse_builtin_types_compatible(void)
6544 {
6545         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6546
6547         eat(T___builtin_types_compatible_p);
6548
6549         expect('(');
6550         add_anchor_token(')');
6551         add_anchor_token(',');
6552         expression->builtin_types_compatible.left = parse_typename();
6553         rem_anchor_token(',');
6554         expect(',');
6555         expression->builtin_types_compatible.right = parse_typename();
6556         rem_anchor_token(')');
6557         expect(')');
6558         expression->base.type = type_int;
6559
6560         return expression;
6561 }
6562
6563 /**
6564  * Parses a __builtin_is_*() compare expression.
6565  */
6566 static expression_t *parse_compare_builtin(void)
6567 {
6568         expression_t *expression;
6569
6570         switch (token.kind) {
6571         case T___builtin_isgreater:
6572                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6573                 break;
6574         case T___builtin_isgreaterequal:
6575                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6576                 break;
6577         case T___builtin_isless:
6578                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6579                 break;
6580         case T___builtin_islessequal:
6581                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6582                 break;
6583         case T___builtin_islessgreater:
6584                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6585                 break;
6586         case T___builtin_isunordered:
6587                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6588                 break;
6589         default:
6590                 internal_errorf(HERE, "invalid compare builtin found");
6591         }
6592         expression->base.source_position = *HERE;
6593         next_token();
6594
6595         expect('(');
6596         add_anchor_token(')');
6597         add_anchor_token(',');
6598         expression->binary.left = parse_assignment_expression();
6599         rem_anchor_token(',');
6600         expect(',');
6601         expression->binary.right = parse_assignment_expression();
6602         rem_anchor_token(')');
6603         expect(')');
6604
6605         type_t *const orig_type_left  = expression->binary.left->base.type;
6606         type_t *const orig_type_right = expression->binary.right->base.type;
6607
6608         type_t *const type_left  = skip_typeref(orig_type_left);
6609         type_t *const type_right = skip_typeref(orig_type_right);
6610         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6611                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6612                         type_error_incompatible("invalid operands in comparison",
6613                                 &expression->base.source_position, orig_type_left, orig_type_right);
6614                 }
6615         } else {
6616                 semantic_comparison(&expression->binary);
6617         }
6618
6619         return expression;
6620 }
6621
6622 /**
6623  * Parses a MS assume() expression.
6624  */
6625 static expression_t *parse_assume(void)
6626 {
6627         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6628
6629         eat(T__assume);
6630
6631         expect('(');
6632         add_anchor_token(')');
6633         expression->unary.value = parse_assignment_expression();
6634         rem_anchor_token(')');
6635         expect(')');
6636
6637         expression->base.type = type_void;
6638         return expression;
6639 }
6640
6641 /**
6642  * Return the label for the current symbol or create a new one.
6643  */
6644 static label_t *get_label(void)
6645 {
6646         assert(token.kind == T_IDENTIFIER);
6647         assert(current_function != NULL);
6648
6649         entity_t *label = get_entity(token.base.symbol, NAMESPACE_LABEL);
6650         /* If we find a local label, we already created the declaration. */
6651         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6652                 if (label->base.parent_scope != current_scope) {
6653                         assert(label->base.parent_scope->depth < current_scope->depth);
6654                         current_function->goto_to_outer = true;
6655                 }
6656         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6657                 /* There is no matching label in the same function, so create a new one. */
6658                 source_position_t const nowhere = { NULL, 0, 0, false };
6659                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.base.symbol, &nowhere);
6660                 label_push(label);
6661         }
6662
6663         eat(T_IDENTIFIER);
6664         return &label->label;
6665 }
6666
6667 /**
6668  * Parses a GNU && label address expression.
6669  */
6670 static expression_t *parse_label_address(void)
6671 {
6672         source_position_t const source_position = *HERE;
6673         eat(T_ANDAND);
6674         if (token.kind != T_IDENTIFIER) {
6675                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6676                 return create_error_expression();
6677         }
6678
6679         label_t *const label = get_label();
6680         label->used          = true;
6681         label->address_taken = true;
6682
6683         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6684         expression->base.source_position = source_position;
6685
6686         /* label address is treated as a void pointer */
6687         expression->base.type           = type_void_ptr;
6688         expression->label_address.label = label;
6689         return expression;
6690 }
6691
6692 /**
6693  * Parse a microsoft __noop expression.
6694  */
6695 static expression_t *parse_noop_expression(void)
6696 {
6697         /* the result is a (int)0 */
6698         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6699         literal->base.type           = type_int;
6700         literal->literal.value.begin = "__noop";
6701         literal->literal.value.size  = 6;
6702
6703         eat(T___noop);
6704
6705         if (token.kind == '(') {
6706                 /* parse arguments */
6707                 eat('(');
6708                 add_anchor_token(')');
6709                 add_anchor_token(',');
6710
6711                 if (token.kind != ')') do {
6712                         (void)parse_assignment_expression();
6713                 } while (next_if(','));
6714
6715                 rem_anchor_token(',');
6716                 rem_anchor_token(')');
6717         }
6718         expect(')');
6719
6720         return literal;
6721 }
6722
6723 /**
6724  * Parses a primary expression.
6725  */
6726 static expression_t *parse_primary_expression(void)
6727 {
6728         switch (token.kind) {
6729         case T_false:                        return parse_boolean_literal(false);
6730         case T_true:                         return parse_boolean_literal(true);
6731         case T_INTEGER:
6732         case T_FLOATINGPOINT:                return parse_number_literal();
6733         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6734         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6735         case T_STRING_LITERAL:
6736         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6737         case T___FUNCTION__:
6738         case T___func__:                     return parse_function_keyword();
6739         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6740         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6741         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6742         case T___builtin_offsetof:           return parse_offsetof();
6743         case T___builtin_va_start:           return parse_va_start();
6744         case T___builtin_va_arg:             return parse_va_arg();
6745         case T___builtin_va_copy:            return parse_va_copy();
6746         case T___builtin_isgreater:
6747         case T___builtin_isgreaterequal:
6748         case T___builtin_isless:
6749         case T___builtin_islessequal:
6750         case T___builtin_islessgreater:
6751         case T___builtin_isunordered:        return parse_compare_builtin();
6752         case T___builtin_constant_p:         return parse_builtin_constant();
6753         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6754         case T__assume:                      return parse_assume();
6755         case T_ANDAND:
6756                 if (GNU_MODE)
6757                         return parse_label_address();
6758                 break;
6759
6760         case '(':                            return parse_parenthesized_expression();
6761         case T___noop:                       return parse_noop_expression();
6762
6763         /* Gracefully handle type names while parsing expressions. */
6764         case T_COLONCOLON:
6765                 return parse_reference();
6766         case T_IDENTIFIER:
6767                 if (!is_typedef_symbol(token.base.symbol)) {
6768                         return parse_reference();
6769                 }
6770                 /* FALLTHROUGH */
6771         DECLARATION_START {
6772                 source_position_t const  pos = *HERE;
6773                 declaration_specifiers_t specifiers;
6774                 parse_declaration_specifiers(&specifiers);
6775                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6776                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6777                 return create_error_expression();
6778         }
6779         }
6780
6781         errorf(HERE, "unexpected token %K, expected an expression", &token);
6782         eat_until_anchor();
6783         return create_error_expression();
6784 }
6785
6786 static expression_t *parse_array_expression(expression_t *left)
6787 {
6788         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6789         array_access_expression_t *const arr  = &expr->array_access;
6790
6791         eat('[');
6792         add_anchor_token(']');
6793
6794         expression_t *const inside = parse_expression();
6795
6796         type_t *const orig_type_left   = left->base.type;
6797         type_t *const orig_type_inside = inside->base.type;
6798
6799         type_t *const type_left   = skip_typeref(orig_type_left);
6800         type_t *const type_inside = skip_typeref(orig_type_inside);
6801
6802         expression_t *ref;
6803         expression_t *idx;
6804         type_t       *idx_type;
6805         type_t       *res_type;
6806         if (is_type_pointer(type_left)) {
6807                 ref      = left;
6808                 idx      = inside;
6809                 idx_type = type_inside;
6810                 res_type = type_left->pointer.points_to;
6811                 goto check_idx;
6812         } else if (is_type_pointer(type_inside)) {
6813                 arr->flipped = true;
6814                 ref      = inside;
6815                 idx      = left;
6816                 idx_type = type_left;
6817                 res_type = type_inside->pointer.points_to;
6818 check_idx:
6819                 res_type = automatic_type_conversion(res_type);
6820                 if (!is_type_integer(idx_type)) {
6821                         errorf(&idx->base.source_position, "array subscript must have integer type");
6822                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6823                         source_position_t const *const pos = &idx->base.source_position;
6824                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6825                 }
6826         } else {
6827                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6828                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6829                 }
6830                 res_type = type_error_type;
6831                 ref      = left;
6832                 idx      = inside;
6833         }
6834
6835         arr->array_ref = ref;
6836         arr->index     = idx;
6837         arr->base.type = res_type;
6838
6839         rem_anchor_token(']');
6840         expect(']');
6841         return expr;
6842 }
6843
6844 static bool is_bitfield(const expression_t *expression)
6845 {
6846         return expression->kind == EXPR_SELECT
6847                 && expression->select.compound_entry->compound_member.bitfield;
6848 }
6849
6850 static expression_t *parse_typeprop(expression_kind_t const kind)
6851 {
6852         expression_t  *tp_expression = allocate_expression_zero(kind);
6853         tp_expression->base.type     = type_size_t;
6854
6855         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6856
6857         type_t       *orig_type;
6858         expression_t *expression;
6859         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6860                 source_position_t const pos = *HERE;
6861                 next_token();
6862                 add_anchor_token(')');
6863                 orig_type = parse_typename();
6864                 rem_anchor_token(')');
6865                 expect(')');
6866
6867                 if (token.kind == '{') {
6868                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6869                          * starting with a compound literal */
6870                         expression = parse_compound_literal(&pos, orig_type);
6871                         goto typeprop_expression;
6872                 }
6873         } else {
6874                 expression = parse_subexpression(PREC_UNARY);
6875
6876 typeprop_expression:
6877                 if (is_bitfield(expression)) {
6878                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6879                         errorf(&tp_expression->base.source_position,
6880                                    "operand of %s expression must not be a bitfield", what);
6881                 }
6882
6883                 tp_expression->typeprop.tp_expression = expression;
6884
6885                 orig_type = revert_automatic_type_conversion(expression);
6886                 expression->base.type = orig_type;
6887         }
6888
6889         tp_expression->typeprop.type   = orig_type;
6890         type_t const* const type       = skip_typeref(orig_type);
6891         char   const*       wrong_type = NULL;
6892         if (is_type_incomplete(type)) {
6893                 if (!is_type_void(type) || !GNU_MODE)
6894                         wrong_type = "incomplete";
6895         } else if (type->kind == TYPE_FUNCTION) {
6896                 if (GNU_MODE) {
6897                         /* function types are allowed (and return 1) */
6898                         source_position_t const *const pos  = &tp_expression->base.source_position;
6899                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6900                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6901                 } else {
6902                         wrong_type = "function";
6903                 }
6904         }
6905
6906         if (wrong_type != NULL) {
6907                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6908                 errorf(&tp_expression->base.source_position,
6909                                 "operand of %s expression must not be of %s type '%T'",
6910                                 what, wrong_type, orig_type);
6911         }
6912
6913         return tp_expression;
6914 }
6915
6916 static expression_t *parse_sizeof(void)
6917 {
6918         return parse_typeprop(EXPR_SIZEOF);
6919 }
6920
6921 static expression_t *parse_alignof(void)
6922 {
6923         return parse_typeprop(EXPR_ALIGNOF);
6924 }
6925
6926 static expression_t *parse_select_expression(expression_t *addr)
6927 {
6928         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6929         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6930         source_position_t const pos = *HERE;
6931         next_token();
6932
6933         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6934         if (!symbol)
6935                 return create_error_expression();
6936
6937         type_t *const orig_type = addr->base.type;
6938         type_t *const type      = skip_typeref(orig_type);
6939
6940         type_t *type_left;
6941         bool    saw_error = false;
6942         if (is_type_pointer(type)) {
6943                 if (!select_left_arrow) {
6944                         errorf(&pos,
6945                                "request for member '%Y' in something not a struct or union, but '%T'",
6946                                symbol, orig_type);
6947                         saw_error = true;
6948                 }
6949                 type_left = skip_typeref(type->pointer.points_to);
6950         } else {
6951                 if (select_left_arrow && is_type_valid(type)) {
6952                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6953                         saw_error = true;
6954                 }
6955                 type_left = type;
6956         }
6957
6958         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6959             type_left->kind != TYPE_COMPOUND_UNION) {
6960
6961                 if (is_type_valid(type_left) && !saw_error) {
6962                         errorf(&pos,
6963                                "request for member '%Y' in something not a struct or union, but '%T'",
6964                                symbol, type_left);
6965                 }
6966                 return create_error_expression();
6967         }
6968
6969         compound_t *compound = type_left->compound.compound;
6970         if (!compound->complete) {
6971                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6972                        symbol, type_left);
6973                 return create_error_expression();
6974         }
6975
6976         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6977         expression_t      *result     =
6978                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6979
6980         if (result == NULL) {
6981                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6982                 return create_error_expression();
6983         }
6984
6985         return result;
6986 }
6987
6988 static void check_call_argument(type_t          *expected_type,
6989                                 call_argument_t *argument, unsigned pos)
6990 {
6991         type_t         *expected_type_skip = skip_typeref(expected_type);
6992         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6993         expression_t   *arg_expr           = argument->expression;
6994         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6995
6996         /* handle transparent union gnu extension */
6997         if (is_type_union(expected_type_skip)
6998                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6999                 compound_t *union_decl  = expected_type_skip->compound.compound;
7000                 type_t     *best_type   = NULL;
7001                 entity_t   *entry       = union_decl->members.entities;
7002                 for ( ; entry != NULL; entry = entry->base.next) {
7003                         assert(is_declaration(entry));
7004                         type_t *decl_type = entry->declaration.type;
7005                         error = semantic_assign(decl_type, arg_expr);
7006                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7007                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7008                                 continue;
7009
7010                         if (error == ASSIGN_SUCCESS) {
7011                                 best_type = decl_type;
7012                         } else if (best_type == NULL) {
7013                                 best_type = decl_type;
7014                         }
7015                 }
7016
7017                 if (best_type != NULL) {
7018                         expected_type = best_type;
7019                 }
7020         }
7021
7022         error                = semantic_assign(expected_type, arg_expr);
7023         argument->expression = create_implicit_cast(arg_expr, expected_type);
7024
7025         if (error != ASSIGN_SUCCESS) {
7026                 /* report exact scope in error messages (like "in argument 3") */
7027                 char buf[64];
7028                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7029                 report_assign_error(error, expected_type, arg_expr, buf,
7030                                     &arg_expr->base.source_position);
7031         } else {
7032                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7033                 if (!types_compatible(expected_type_skip, promoted_type) &&
7034                     !types_compatible(expected_type_skip, type_void_ptr) &&
7035                     !types_compatible(type_void_ptr,      promoted_type)) {
7036                         /* Deliberately show the skipped types in this warning */
7037                         source_position_t const *const apos = &arg_expr->base.source_position;
7038                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7039                 }
7040         }
7041 }
7042
7043 /**
7044  * Handle the semantic restrictions of builtin calls
7045  */
7046 static void handle_builtin_argument_restrictions(call_expression_t *call)
7047 {
7048         entity_t *entity = call->function->reference.entity;
7049         switch (entity->function.btk) {
7050         case BUILTIN_FIRM:
7051                 switch (entity->function.b.firm_builtin_kind) {
7052                 case ir_bk_return_address:
7053                 case ir_bk_frame_address: {
7054                         /* argument must be constant */
7055                         call_argument_t *argument = call->arguments;
7056
7057                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7058                                 errorf(&call->base.source_position,
7059                                            "argument of '%Y' must be a constant expression",
7060                                            call->function->reference.entity->base.symbol);
7061                         }
7062                         break;
7063                 }
7064                 case ir_bk_prefetch:
7065                         /* second and third argument must be constant if existent */
7066                         if (call->arguments == NULL)
7067                                 break;
7068                         call_argument_t *rw = call->arguments->next;
7069                         call_argument_t *locality = NULL;
7070
7071                         if (rw != NULL) {
7072                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7073                                         errorf(&call->base.source_position,
7074                                                    "second argument of '%Y' must be a constant expression",
7075                                                    call->function->reference.entity->base.symbol);
7076                                 }
7077                                 locality = rw->next;
7078                         }
7079                         if (locality != NULL) {
7080                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7081                                         errorf(&call->base.source_position,
7082                                                    "third argument of '%Y' must be a constant expression",
7083                                                    call->function->reference.entity->base.symbol);
7084                                 }
7085                                 locality = rw->next;
7086                         }
7087                         break;
7088                 default:
7089                         break;
7090                 }
7091
7092         case BUILTIN_OBJECT_SIZE:
7093                 if (call->arguments == NULL)
7094                         break;
7095
7096                 call_argument_t *arg = call->arguments->next;
7097                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7098                         errorf(&call->base.source_position,
7099                                    "second argument of '%Y' must be a constant expression",
7100                                    call->function->reference.entity->base.symbol);
7101                 }
7102                 break;
7103         default:
7104                 break;
7105         }
7106 }
7107
7108 /**
7109  * Parse a call expression, ie. expression '( ... )'.
7110  *
7111  * @param expression  the function address
7112  */
7113 static expression_t *parse_call_expression(expression_t *expression)
7114 {
7115         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7116         call_expression_t *call   = &result->call;
7117         call->function            = expression;
7118
7119         type_t *const orig_type = expression->base.type;
7120         type_t *const type      = skip_typeref(orig_type);
7121
7122         function_type_t *function_type = NULL;
7123         if (is_type_pointer(type)) {
7124                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7125
7126                 if (is_type_function(to_type)) {
7127                         function_type   = &to_type->function;
7128                         call->base.type = function_type->return_type;
7129                 }
7130         }
7131
7132         if (function_type == NULL && is_type_valid(type)) {
7133                 errorf(HERE,
7134                        "called object '%E' (type '%T') is not a pointer to a function",
7135                        expression, orig_type);
7136         }
7137
7138         /* parse arguments */
7139         eat('(');
7140         add_anchor_token(')');
7141         add_anchor_token(',');
7142
7143         if (token.kind != ')') {
7144                 call_argument_t **anchor = &call->arguments;
7145                 do {
7146                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7147                         argument->expression = parse_assignment_expression();
7148
7149                         *anchor = argument;
7150                         anchor  = &argument->next;
7151                 } while (next_if(','));
7152         }
7153         rem_anchor_token(',');
7154         rem_anchor_token(')');
7155         expect(')');
7156
7157         if (function_type == NULL)
7158                 return result;
7159
7160         /* check type and count of call arguments */
7161         function_parameter_t *parameter = function_type->parameters;
7162         call_argument_t      *argument  = call->arguments;
7163         if (!function_type->unspecified_parameters) {
7164                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7165                                 parameter = parameter->next, argument = argument->next) {
7166                         check_call_argument(parameter->type, argument, ++pos);
7167                 }
7168
7169                 if (parameter != NULL) {
7170                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7171                 } else if (argument != NULL && !function_type->variadic) {
7172                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7173                 }
7174         }
7175
7176         /* do default promotion for other arguments */
7177         for (; argument != NULL; argument = argument->next) {
7178                 type_t *argument_type = argument->expression->base.type;
7179                 if (!is_type_object(skip_typeref(argument_type))) {
7180                         errorf(&argument->expression->base.source_position,
7181                                "call argument '%E' must not be void", argument->expression);
7182                 }
7183
7184                 argument_type = get_default_promoted_type(argument_type);
7185
7186                 argument->expression
7187                         = create_implicit_cast(argument->expression, argument_type);
7188         }
7189
7190         check_format(call);
7191
7192         if (is_type_compound(skip_typeref(function_type->return_type))) {
7193                 source_position_t const *const pos = &expression->base.source_position;
7194                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7195         }
7196
7197         if (expression->kind == EXPR_REFERENCE) {
7198                 reference_expression_t *reference = &expression->reference;
7199                 if (reference->entity->kind == ENTITY_FUNCTION &&
7200                     reference->entity->function.btk != BUILTIN_NONE)
7201                         handle_builtin_argument_restrictions(call);
7202         }
7203
7204         return result;
7205 }
7206
7207 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7208
7209 static bool same_compound_type(const type_t *type1, const type_t *type2)
7210 {
7211         return
7212                 is_type_compound(type1) &&
7213                 type1->kind == type2->kind &&
7214                 type1->compound.compound == type2->compound.compound;
7215 }
7216
7217 static expression_t const *get_reference_address(expression_t const *expr)
7218 {
7219         bool regular_take_address = true;
7220         for (;;) {
7221                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7222                         expr = expr->unary.value;
7223                 } else {
7224                         regular_take_address = false;
7225                 }
7226
7227                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7228                         break;
7229
7230                 expr = expr->unary.value;
7231         }
7232
7233         if (expr->kind != EXPR_REFERENCE)
7234                 return NULL;
7235
7236         /* special case for functions which are automatically converted to a
7237          * pointer to function without an extra TAKE_ADDRESS operation */
7238         if (!regular_take_address &&
7239                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7240                 return NULL;
7241         }
7242
7243         return expr;
7244 }
7245
7246 static void warn_reference_address_as_bool(expression_t const* expr)
7247 {
7248         expr = get_reference_address(expr);
7249         if (expr != NULL) {
7250                 source_position_t const *const pos = &expr->base.source_position;
7251                 entity_t          const *const ent = expr->reference.entity;
7252                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7253         }
7254 }
7255
7256 static void warn_assignment_in_condition(const expression_t *const expr)
7257 {
7258         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7259                 return;
7260         if (expr->base.parenthesized)
7261                 return;
7262         source_position_t const *const pos = &expr->base.source_position;
7263         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7264 }
7265
7266 static void semantic_condition(expression_t const *const expr,
7267                                char const *const context)
7268 {
7269         type_t *const type = skip_typeref(expr->base.type);
7270         if (is_type_scalar(type)) {
7271                 warn_reference_address_as_bool(expr);
7272                 warn_assignment_in_condition(expr);
7273         } else if (is_type_valid(type)) {
7274                 errorf(&expr->base.source_position,
7275                                 "%s must have scalar type", context);
7276         }
7277 }
7278
7279 /**
7280  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7281  *
7282  * @param expression  the conditional expression
7283  */
7284 static expression_t *parse_conditional_expression(expression_t *expression)
7285 {
7286         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7287
7288         conditional_expression_t *conditional = &result->conditional;
7289         conditional->condition                = expression;
7290
7291         eat('?');
7292         add_anchor_token(':');
7293
7294         /* §6.5.15:2  The first operand shall have scalar type. */
7295         semantic_condition(expression, "condition of conditional operator");
7296
7297         expression_t *true_expression = expression;
7298         bool          gnu_cond = false;
7299         if (GNU_MODE && token.kind == ':') {
7300                 gnu_cond = true;
7301         } else {
7302                 true_expression = parse_expression();
7303         }
7304         rem_anchor_token(':');
7305         expect(':');
7306         expression_t *false_expression =
7307                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7308
7309         type_t *const orig_true_type  = true_expression->base.type;
7310         type_t *const orig_false_type = false_expression->base.type;
7311         type_t *const true_type       = skip_typeref(orig_true_type);
7312         type_t *const false_type      = skip_typeref(orig_false_type);
7313
7314         /* 6.5.15.3 */
7315         source_position_t const *const pos = &conditional->base.source_position;
7316         type_t                        *result_type;
7317         if (is_type_void(true_type) || is_type_void(false_type)) {
7318                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7319                 if (true_expression->kind == EXPR_UNARY_THROW) {
7320                         result_type = false_type;
7321                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7322                         result_type = true_type;
7323                 } else {
7324                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7325                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7326                         }
7327                         result_type = type_void;
7328                 }
7329         } else if (is_type_arithmetic(true_type)
7330                    && is_type_arithmetic(false_type)) {
7331                 result_type = semantic_arithmetic(true_type, false_type);
7332         } else if (same_compound_type(true_type, false_type)) {
7333                 /* just take 1 of the 2 types */
7334                 result_type = true_type;
7335         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7336                 type_t *pointer_type;
7337                 type_t *other_type;
7338                 expression_t *other_expression;
7339                 if (is_type_pointer(true_type) &&
7340                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7341                         pointer_type     = true_type;
7342                         other_type       = false_type;
7343                         other_expression = false_expression;
7344                 } else {
7345                         pointer_type     = false_type;
7346                         other_type       = true_type;
7347                         other_expression = true_expression;
7348                 }
7349
7350                 if (is_null_pointer_constant(other_expression)) {
7351                         result_type = pointer_type;
7352                 } else if (is_type_pointer(other_type)) {
7353                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7354                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7355
7356                         type_t *to;
7357                         if (is_type_void(to1) || is_type_void(to2)) {
7358                                 to = type_void;
7359                         } else if (types_compatible(get_unqualified_type(to1),
7360                                                     get_unqualified_type(to2))) {
7361                                 to = to1;
7362                         } else {
7363                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7364                                 to = type_void;
7365                         }
7366
7367                         type_t *const type =
7368                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7369                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7370                 } else if (is_type_integer(other_type)) {
7371                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7372                         result_type = pointer_type;
7373                 } else {
7374                         goto types_incompatible;
7375                 }
7376         } else {
7377 types_incompatible:
7378                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7379                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7380                 }
7381                 result_type = type_error_type;
7382         }
7383
7384         conditional->true_expression
7385                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7386         conditional->false_expression
7387                 = create_implicit_cast(false_expression, result_type);
7388         conditional->base.type = result_type;
7389         return result;
7390 }
7391
7392 /**
7393  * Parse an extension expression.
7394  */
7395 static expression_t *parse_extension(void)
7396 {
7397         PUSH_EXTENSION();
7398         expression_t *expression = parse_subexpression(PREC_UNARY);
7399         POP_EXTENSION();
7400         return expression;
7401 }
7402
7403 /**
7404  * Parse a __builtin_classify_type() expression.
7405  */
7406 static expression_t *parse_builtin_classify_type(void)
7407 {
7408         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7409         result->base.type    = type_int;
7410
7411         eat(T___builtin_classify_type);
7412
7413         expect('(');
7414         add_anchor_token(')');
7415         expression_t *expression = parse_expression();
7416         rem_anchor_token(')');
7417         expect(')');
7418         result->classify_type.type_expression = expression;
7419
7420         return result;
7421 }
7422
7423 /**
7424  * Parse a delete expression
7425  * ISO/IEC 14882:1998(E) §5.3.5
7426  */
7427 static expression_t *parse_delete(void)
7428 {
7429         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7430         result->base.type          = type_void;
7431
7432         eat(T_delete);
7433
7434         if (next_if('[')) {
7435                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7436                 expect(']');
7437         }
7438
7439         expression_t *const value = parse_subexpression(PREC_CAST);
7440         result->unary.value = value;
7441
7442         type_t *const type = skip_typeref(value->base.type);
7443         if (!is_type_pointer(type)) {
7444                 if (is_type_valid(type)) {
7445                         errorf(&value->base.source_position,
7446                                         "operand of delete must have pointer type");
7447                 }
7448         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7449                 source_position_t const *const pos = &value->base.source_position;
7450                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7451         }
7452
7453         return result;
7454 }
7455
7456 /**
7457  * Parse a throw expression
7458  * ISO/IEC 14882:1998(E) §15:1
7459  */
7460 static expression_t *parse_throw(void)
7461 {
7462         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7463         result->base.type          = type_void;
7464
7465         eat(T_throw);
7466
7467         expression_t *value = NULL;
7468         switch (token.kind) {
7469                 EXPRESSION_START {
7470                         value = parse_assignment_expression();
7471                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7472                         type_t *const orig_type = value->base.type;
7473                         type_t *const type      = skip_typeref(orig_type);
7474                         if (is_type_incomplete(type)) {
7475                                 errorf(&value->base.source_position,
7476                                                 "cannot throw object of incomplete type '%T'", orig_type);
7477                         } else if (is_type_pointer(type)) {
7478                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7479                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7480                                         errorf(&value->base.source_position,
7481                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7482                                 }
7483                         }
7484                 }
7485
7486                 default:
7487                         break;
7488         }
7489         result->unary.value = value;
7490
7491         return result;
7492 }
7493
7494 static bool check_pointer_arithmetic(const source_position_t *source_position,
7495                                      type_t *pointer_type,
7496                                      type_t *orig_pointer_type)
7497 {
7498         type_t *points_to = pointer_type->pointer.points_to;
7499         points_to = skip_typeref(points_to);
7500
7501         if (is_type_incomplete(points_to)) {
7502                 if (!GNU_MODE || !is_type_void(points_to)) {
7503                         errorf(source_position,
7504                                "arithmetic with pointer to incomplete type '%T' not allowed",
7505                                orig_pointer_type);
7506                         return false;
7507                 } else {
7508                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7509                 }
7510         } else if (is_type_function(points_to)) {
7511                 if (!GNU_MODE) {
7512                         errorf(source_position,
7513                                "arithmetic with pointer to function type '%T' not allowed",
7514                                orig_pointer_type);
7515                         return false;
7516                 } else {
7517                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7518                 }
7519         }
7520         return true;
7521 }
7522
7523 static bool is_lvalue(const expression_t *expression)
7524 {
7525         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7526         switch (expression->kind) {
7527         case EXPR_ARRAY_ACCESS:
7528         case EXPR_COMPOUND_LITERAL:
7529         case EXPR_REFERENCE:
7530         case EXPR_SELECT:
7531         case EXPR_UNARY_DEREFERENCE:
7532                 return true;
7533
7534         default: {
7535                 type_t *type = skip_typeref(expression->base.type);
7536                 return
7537                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7538                         is_type_reference(type) ||
7539                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7540                          * error before, which maybe prevented properly recognizing it as
7541                          * lvalue. */
7542                         !is_type_valid(type);
7543         }
7544         }
7545 }
7546
7547 static void semantic_incdec(unary_expression_t *expression)
7548 {
7549         type_t *const orig_type = expression->value->base.type;
7550         type_t *const type      = skip_typeref(orig_type);
7551         if (is_type_pointer(type)) {
7552                 if (!check_pointer_arithmetic(&expression->base.source_position,
7553                                               type, orig_type)) {
7554                         return;
7555                 }
7556         } else if (!is_type_real(type) && is_type_valid(type)) {
7557                 /* TODO: improve error message */
7558                 errorf(&expression->base.source_position,
7559                        "operation needs an arithmetic or pointer type");
7560                 return;
7561         }
7562         if (!is_lvalue(expression->value)) {
7563                 /* TODO: improve error message */
7564                 errorf(&expression->base.source_position, "lvalue required as operand");
7565         }
7566         expression->base.type = orig_type;
7567 }
7568
7569 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7570 {
7571         type_t *const res_type = promote_integer(type);
7572         expr->base.type = res_type;
7573         expr->value     = create_implicit_cast(expr->value, res_type);
7574 }
7575
7576 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7577 {
7578         type_t *const orig_type = expression->value->base.type;
7579         type_t *const type      = skip_typeref(orig_type);
7580         if (!is_type_arithmetic(type)) {
7581                 if (is_type_valid(type)) {
7582                         /* TODO: improve error message */
7583                         errorf(&expression->base.source_position,
7584                                 "operation needs an arithmetic type");
7585                 }
7586                 return;
7587         } else if (is_type_integer(type)) {
7588                 promote_unary_int_expr(expression, type);
7589         } else {
7590                 expression->base.type = orig_type;
7591         }
7592 }
7593
7594 static void semantic_unexpr_plus(unary_expression_t *expression)
7595 {
7596         semantic_unexpr_arithmetic(expression);
7597         source_position_t const *const pos = &expression->base.source_position;
7598         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7599 }
7600
7601 static void semantic_not(unary_expression_t *expression)
7602 {
7603         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7604         semantic_condition(expression->value, "operand of !");
7605         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7606 }
7607
7608 static void semantic_unexpr_integer(unary_expression_t *expression)
7609 {
7610         type_t *const orig_type = expression->value->base.type;
7611         type_t *const type      = skip_typeref(orig_type);
7612         if (!is_type_integer(type)) {
7613                 if (is_type_valid(type)) {
7614                         errorf(&expression->base.source_position,
7615                                "operand of ~ must be of integer type");
7616                 }
7617                 return;
7618         }
7619
7620         promote_unary_int_expr(expression, type);
7621 }
7622
7623 static void semantic_dereference(unary_expression_t *expression)
7624 {
7625         type_t *const orig_type = expression->value->base.type;
7626         type_t *const type      = skip_typeref(orig_type);
7627         if (!is_type_pointer(type)) {
7628                 if (is_type_valid(type)) {
7629                         errorf(&expression->base.source_position,
7630                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7631                 }
7632                 return;
7633         }
7634
7635         type_t *result_type   = type->pointer.points_to;
7636         result_type           = automatic_type_conversion(result_type);
7637         expression->base.type = result_type;
7638 }
7639
7640 /**
7641  * Record that an address is taken (expression represents an lvalue).
7642  *
7643  * @param expression       the expression
7644  * @param may_be_register  if true, the expression might be an register
7645  */
7646 static void set_address_taken(expression_t *expression, bool may_be_register)
7647 {
7648         if (expression->kind != EXPR_REFERENCE)
7649                 return;
7650
7651         entity_t *const entity = expression->reference.entity;
7652
7653         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7654                 return;
7655
7656         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7657                         && !may_be_register) {
7658                 source_position_t const *const pos = &expression->base.source_position;
7659                 errorf(pos, "address of register '%N' requested", entity);
7660         }
7661
7662         entity->variable.address_taken = true;
7663 }
7664
7665 /**
7666  * Check the semantic of the address taken expression.
7667  */
7668 static void semantic_take_addr(unary_expression_t *expression)
7669 {
7670         expression_t *value = expression->value;
7671         value->base.type    = revert_automatic_type_conversion(value);
7672
7673         type_t *orig_type = value->base.type;
7674         type_t *type      = skip_typeref(orig_type);
7675         if (!is_type_valid(type))
7676                 return;
7677
7678         /* §6.5.3.2 */
7679         if (!is_lvalue(value)) {
7680                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7681         }
7682         if (is_bitfield(value)) {
7683                 errorf(&expression->base.source_position,
7684                        "'&' not allowed on bitfield");
7685         }
7686
7687         set_address_taken(value, false);
7688
7689         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7690 }
7691
7692 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7693 static expression_t *parse_##unexpression_type(void)                         \
7694 {                                                                            \
7695         expression_t *unary_expression                                           \
7696                 = allocate_expression_zero(unexpression_type);                       \
7697         eat(token_kind);                                                         \
7698         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7699                                                                                  \
7700         sfunc(&unary_expression->unary);                                         \
7701                                                                                  \
7702         return unary_expression;                                                 \
7703 }
7704
7705 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7706                                semantic_unexpr_arithmetic)
7707 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7708                                semantic_unexpr_plus)
7709 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7710                                semantic_not)
7711 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7712                                semantic_dereference)
7713 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7714                                semantic_take_addr)
7715 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7716                                semantic_unexpr_integer)
7717 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7718                                semantic_incdec)
7719 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7720                                semantic_incdec)
7721
7722 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7723                                                sfunc)                         \
7724 static expression_t *parse_##unexpression_type(expression_t *left)            \
7725 {                                                                             \
7726         expression_t *unary_expression                                            \
7727                 = allocate_expression_zero(unexpression_type);                        \
7728         eat(token_kind);                                                          \
7729         unary_expression->unary.value = left;                                     \
7730                                                                                   \
7731         sfunc(&unary_expression->unary);                                          \
7732                                                                               \
7733         return unary_expression;                                                  \
7734 }
7735
7736 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7737                                        EXPR_UNARY_POSTFIX_INCREMENT,
7738                                        semantic_incdec)
7739 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7740                                        EXPR_UNARY_POSTFIX_DECREMENT,
7741                                        semantic_incdec)
7742
7743 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7744 {
7745         /* TODO: handle complex + imaginary types */
7746
7747         type_left  = get_unqualified_type(type_left);
7748         type_right = get_unqualified_type(type_right);
7749
7750         /* §6.3.1.8 Usual arithmetic conversions */
7751         if (type_left == type_long_double || type_right == type_long_double) {
7752                 return type_long_double;
7753         } else if (type_left == type_double || type_right == type_double) {
7754                 return type_double;
7755         } else if (type_left == type_float || type_right == type_float) {
7756                 return type_float;
7757         }
7758
7759         type_left  = promote_integer(type_left);
7760         type_right = promote_integer(type_right);
7761
7762         if (type_left == type_right)
7763                 return type_left;
7764
7765         bool     const signed_left  = is_type_signed(type_left);
7766         bool     const signed_right = is_type_signed(type_right);
7767         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7768         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7769
7770         if (signed_left == signed_right)
7771                 return rank_left >= rank_right ? type_left : type_right;
7772
7773         unsigned           s_rank;
7774         unsigned           u_rank;
7775         atomic_type_kind_t s_akind;
7776         atomic_type_kind_t u_akind;
7777         type_t *s_type;
7778         type_t *u_type;
7779         if (signed_left) {
7780                 s_type = type_left;
7781                 u_type = type_right;
7782         } else {
7783                 s_type = type_right;
7784                 u_type = type_left;
7785         }
7786         s_akind = get_akind(s_type);
7787         u_akind = get_akind(u_type);
7788         s_rank  = get_akind_rank(s_akind);
7789         u_rank  = get_akind_rank(u_akind);
7790
7791         if (u_rank >= s_rank)
7792                 return u_type;
7793
7794         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7795                 return s_type;
7796
7797         switch (s_akind) {
7798         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7799         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7800         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7801
7802         default: panic("invalid atomic type");
7803         }
7804 }
7805
7806 /**
7807  * Check the semantic restrictions for a binary expression.
7808  */
7809 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7810 {
7811         expression_t *const left            = expression->left;
7812         expression_t *const right           = expression->right;
7813         type_t       *const orig_type_left  = left->base.type;
7814         type_t       *const orig_type_right = right->base.type;
7815         type_t       *const type_left       = skip_typeref(orig_type_left);
7816         type_t       *const type_right      = skip_typeref(orig_type_right);
7817
7818         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7819                 /* TODO: improve error message */
7820                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7821                         errorf(&expression->base.source_position,
7822                                "operation needs arithmetic types");
7823                 }
7824                 return;
7825         }
7826
7827         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7828         expression->left      = create_implicit_cast(left, arithmetic_type);
7829         expression->right     = create_implicit_cast(right, arithmetic_type);
7830         expression->base.type = arithmetic_type;
7831 }
7832
7833 static void semantic_binexpr_integer(binary_expression_t *const expression)
7834 {
7835         expression_t *const left            = expression->left;
7836         expression_t *const right           = expression->right;
7837         type_t       *const orig_type_left  = left->base.type;
7838         type_t       *const orig_type_right = right->base.type;
7839         type_t       *const type_left       = skip_typeref(orig_type_left);
7840         type_t       *const type_right      = skip_typeref(orig_type_right);
7841
7842         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7843                 /* TODO: improve error message */
7844                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7845                         errorf(&expression->base.source_position,
7846                                "operation needs integer types");
7847                 }
7848                 return;
7849         }
7850
7851         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7852         expression->left      = create_implicit_cast(left, result_type);
7853         expression->right     = create_implicit_cast(right, result_type);
7854         expression->base.type = result_type;
7855 }
7856
7857 static void warn_div_by_zero(binary_expression_t const *const expression)
7858 {
7859         if (!is_type_integer(expression->base.type))
7860                 return;
7861
7862         expression_t const *const right = expression->right;
7863         /* The type of the right operand can be different for /= */
7864         if (is_type_integer(right->base.type)                    &&
7865             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7866             !fold_constant_to_bool(right)) {
7867                 source_position_t const *const pos = &expression->base.source_position;
7868                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7869         }
7870 }
7871
7872 /**
7873  * Check the semantic restrictions for a div/mod expression.
7874  */
7875 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7876 {
7877         semantic_binexpr_arithmetic(expression);
7878         warn_div_by_zero(expression);
7879 }
7880
7881 static void warn_addsub_in_shift(const expression_t *const expr)
7882 {
7883         if (expr->base.parenthesized)
7884                 return;
7885
7886         char op;
7887         switch (expr->kind) {
7888                 case EXPR_BINARY_ADD: op = '+'; break;
7889                 case EXPR_BINARY_SUB: op = '-'; break;
7890                 default:              return;
7891         }
7892
7893         source_position_t const *const pos = &expr->base.source_position;
7894         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7895 }
7896
7897 static bool semantic_shift(binary_expression_t *expression)
7898 {
7899         expression_t *const left            = expression->left;
7900         expression_t *const right           = expression->right;
7901         type_t       *const orig_type_left  = left->base.type;
7902         type_t       *const orig_type_right = right->base.type;
7903         type_t       *      type_left       = skip_typeref(orig_type_left);
7904         type_t       *      type_right      = skip_typeref(orig_type_right);
7905
7906         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7907                 /* TODO: improve error message */
7908                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7909                         errorf(&expression->base.source_position,
7910                                "operands of shift operation must have integer types");
7911                 }
7912                 return false;
7913         }
7914
7915         type_left = promote_integer(type_left);
7916
7917         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7918                 source_position_t const *const pos   = &right->base.source_position;
7919                 long                     const count = fold_constant_to_int(right);
7920                 if (count < 0) {
7921                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7922                 } else if ((unsigned long)count >=
7923                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7924                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7925                 }
7926         }
7927
7928         type_right        = promote_integer(type_right);
7929         expression->right = create_implicit_cast(right, type_right);
7930
7931         return true;
7932 }
7933
7934 static void semantic_shift_op(binary_expression_t *expression)
7935 {
7936         expression_t *const left  = expression->left;
7937         expression_t *const right = expression->right;
7938
7939         if (!semantic_shift(expression))
7940                 return;
7941
7942         warn_addsub_in_shift(left);
7943         warn_addsub_in_shift(right);
7944
7945         type_t *const orig_type_left = left->base.type;
7946         type_t *      type_left      = skip_typeref(orig_type_left);
7947
7948         type_left             = promote_integer(type_left);
7949         expression->left      = create_implicit_cast(left, type_left);
7950         expression->base.type = type_left;
7951 }
7952
7953 static void semantic_add(binary_expression_t *expression)
7954 {
7955         expression_t *const left            = expression->left;
7956         expression_t *const right           = expression->right;
7957         type_t       *const orig_type_left  = left->base.type;
7958         type_t       *const orig_type_right = right->base.type;
7959         type_t       *const type_left       = skip_typeref(orig_type_left);
7960         type_t       *const type_right      = skip_typeref(orig_type_right);
7961
7962         /* §6.5.6 */
7963         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7964                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7965                 expression->left  = create_implicit_cast(left, arithmetic_type);
7966                 expression->right = create_implicit_cast(right, arithmetic_type);
7967                 expression->base.type = arithmetic_type;
7968         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7969                 check_pointer_arithmetic(&expression->base.source_position,
7970                                          type_left, orig_type_left);
7971                 expression->base.type = type_left;
7972         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7973                 check_pointer_arithmetic(&expression->base.source_position,
7974                                          type_right, orig_type_right);
7975                 expression->base.type = type_right;
7976         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7977                 errorf(&expression->base.source_position,
7978                        "invalid operands to binary + ('%T', '%T')",
7979                        orig_type_left, orig_type_right);
7980         }
7981 }
7982
7983 static void semantic_sub(binary_expression_t *expression)
7984 {
7985         expression_t            *const left            = expression->left;
7986         expression_t            *const right           = expression->right;
7987         type_t                  *const orig_type_left  = left->base.type;
7988         type_t                  *const orig_type_right = right->base.type;
7989         type_t                  *const type_left       = skip_typeref(orig_type_left);
7990         type_t                  *const type_right      = skip_typeref(orig_type_right);
7991         source_position_t const *const pos             = &expression->base.source_position;
7992
7993         /* §5.6.5 */
7994         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7995                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7996                 expression->left        = create_implicit_cast(left, arithmetic_type);
7997                 expression->right       = create_implicit_cast(right, arithmetic_type);
7998                 expression->base.type =  arithmetic_type;
7999         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8000                 check_pointer_arithmetic(&expression->base.source_position,
8001                                          type_left, orig_type_left);
8002                 expression->base.type = type_left;
8003         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8004                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
8005                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
8006                 if (!types_compatible(unqual_left, unqual_right)) {
8007                         errorf(pos,
8008                                "subtracting pointers to incompatible types '%T' and '%T'",
8009                                orig_type_left, orig_type_right);
8010                 } else if (!is_type_object(unqual_left)) {
8011                         if (!is_type_void(unqual_left)) {
8012                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8013                                        orig_type_left);
8014                         } else {
8015                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8016                         }
8017                 }
8018                 expression->base.type = type_ptrdiff_t;
8019         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8020                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8021                        orig_type_left, orig_type_right);
8022         }
8023 }
8024
8025 static void warn_string_literal_address(expression_t const* expr)
8026 {
8027         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8028                 expr = expr->unary.value;
8029                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8030                         return;
8031                 expr = expr->unary.value;
8032         }
8033
8034         if (expr->kind == EXPR_STRING_LITERAL
8035                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8036                 source_position_t const *const pos = &expr->base.source_position;
8037                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8038         }
8039 }
8040
8041 static bool maybe_negative(expression_t const *const expr)
8042 {
8043         switch (is_constant_expression(expr)) {
8044                 case EXPR_CLASS_ERROR:    return false;
8045                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8046                 default:                  return true;
8047         }
8048 }
8049
8050 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8051 {
8052         warn_string_literal_address(expr);
8053
8054         expression_t const* const ref = get_reference_address(expr);
8055         if (ref != NULL && is_null_pointer_constant(other)) {
8056                 entity_t const *const ent = ref->reference.entity;
8057                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8058         }
8059
8060         if (!expr->base.parenthesized) {
8061                 switch (expr->base.kind) {
8062                         case EXPR_BINARY_LESS:
8063                         case EXPR_BINARY_GREATER:
8064                         case EXPR_BINARY_LESSEQUAL:
8065                         case EXPR_BINARY_GREATEREQUAL:
8066                         case EXPR_BINARY_NOTEQUAL:
8067                         case EXPR_BINARY_EQUAL:
8068                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8069                                 break;
8070                         default:
8071                                 break;
8072                 }
8073         }
8074 }
8075
8076 /**
8077  * Check the semantics of comparison expressions.
8078  *
8079  * @param expression   The expression to check.
8080  */
8081 static void semantic_comparison(binary_expression_t *expression)
8082 {
8083         source_position_t const *const pos   = &expression->base.source_position;
8084         expression_t            *const left  = expression->left;
8085         expression_t            *const right = expression->right;
8086
8087         warn_comparison(pos, left, right);
8088         warn_comparison(pos, right, left);
8089
8090         type_t *orig_type_left  = left->base.type;
8091         type_t *orig_type_right = right->base.type;
8092         type_t *type_left       = skip_typeref(orig_type_left);
8093         type_t *type_right      = skip_typeref(orig_type_right);
8094
8095         /* TODO non-arithmetic types */
8096         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8097                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8098
8099                 /* test for signed vs unsigned compares */
8100                 if (is_type_integer(arithmetic_type)) {
8101                         bool const signed_left  = is_type_signed(type_left);
8102                         bool const signed_right = is_type_signed(type_right);
8103                         if (signed_left != signed_right) {
8104                                 /* FIXME long long needs better const folding magic */
8105                                 /* TODO check whether constant value can be represented by other type */
8106                                 if ((signed_left  && maybe_negative(left)) ||
8107                                                 (signed_right && maybe_negative(right))) {
8108                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8109                                 }
8110                         }
8111                 }
8112
8113                 expression->left        = create_implicit_cast(left, arithmetic_type);
8114                 expression->right       = create_implicit_cast(right, arithmetic_type);
8115                 expression->base.type   = arithmetic_type;
8116                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8117                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8118                     is_type_float(arithmetic_type)) {
8119                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8120                 }
8121         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8122                 /* TODO check compatibility */
8123         } else if (is_type_pointer(type_left)) {
8124                 expression->right = create_implicit_cast(right, type_left);
8125         } else if (is_type_pointer(type_right)) {
8126                 expression->left = create_implicit_cast(left, type_right);
8127         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8128                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8129         }
8130         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8131 }
8132
8133 /**
8134  * Checks if a compound type has constant fields.
8135  */
8136 static bool has_const_fields(const compound_type_t *type)
8137 {
8138         compound_t *compound = type->compound;
8139         entity_t   *entry    = compound->members.entities;
8140
8141         for (; entry != NULL; entry = entry->base.next) {
8142                 if (!is_declaration(entry))
8143                         continue;
8144
8145                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8146                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8147                         return true;
8148         }
8149
8150         return false;
8151 }
8152
8153 static bool is_valid_assignment_lhs(expression_t const* const left)
8154 {
8155         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8156         type_t *const type_left      = skip_typeref(orig_type_left);
8157
8158         if (!is_lvalue(left)) {
8159                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8160                        left);
8161                 return false;
8162         }
8163
8164         if (left->kind == EXPR_REFERENCE
8165                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8166                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8167                 return false;
8168         }
8169
8170         if (is_type_array(type_left)) {
8171                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8172                 return false;
8173         }
8174         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8175                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8176                        orig_type_left);
8177                 return false;
8178         }
8179         if (is_type_incomplete(type_left)) {
8180                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8181                        left, orig_type_left);
8182                 return false;
8183         }
8184         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8185                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8186                        left, orig_type_left);
8187                 return false;
8188         }
8189
8190         return true;
8191 }
8192
8193 static void semantic_arithmetic_assign(binary_expression_t *expression)
8194 {
8195         expression_t *left            = expression->left;
8196         expression_t *right           = expression->right;
8197         type_t       *orig_type_left  = left->base.type;
8198         type_t       *orig_type_right = right->base.type;
8199
8200         if (!is_valid_assignment_lhs(left))
8201                 return;
8202
8203         type_t *type_left  = skip_typeref(orig_type_left);
8204         type_t *type_right = skip_typeref(orig_type_right);
8205
8206         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8207                 /* TODO: improve error message */
8208                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8209                         errorf(&expression->base.source_position,
8210                                "operation needs arithmetic types");
8211                 }
8212                 return;
8213         }
8214
8215         /* combined instructions are tricky. We can't create an implicit cast on
8216          * the left side, because we need the uncasted form for the store.
8217          * The ast2firm pass has to know that left_type must be right_type
8218          * for the arithmetic operation and create a cast by itself */
8219         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8220         expression->right       = create_implicit_cast(right, arithmetic_type);
8221         expression->base.type   = type_left;
8222 }
8223
8224 static void semantic_divmod_assign(binary_expression_t *expression)
8225 {
8226         semantic_arithmetic_assign(expression);
8227         warn_div_by_zero(expression);
8228 }
8229
8230 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8231 {
8232         expression_t *const left            = expression->left;
8233         expression_t *const right           = expression->right;
8234         type_t       *const orig_type_left  = left->base.type;
8235         type_t       *const orig_type_right = right->base.type;
8236         type_t       *const type_left       = skip_typeref(orig_type_left);
8237         type_t       *const type_right      = skip_typeref(orig_type_right);
8238
8239         if (!is_valid_assignment_lhs(left))
8240                 return;
8241
8242         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8243                 /* combined instructions are tricky. We can't create an implicit cast on
8244                  * the left side, because we need the uncasted form for the store.
8245                  * The ast2firm pass has to know that left_type must be right_type
8246                  * for the arithmetic operation and create a cast by itself */
8247                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8248                 expression->right     = create_implicit_cast(right, arithmetic_type);
8249                 expression->base.type = type_left;
8250         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8251                 check_pointer_arithmetic(&expression->base.source_position,
8252                                          type_left, orig_type_left);
8253                 expression->base.type = type_left;
8254         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8255                 errorf(&expression->base.source_position,
8256                        "incompatible types '%T' and '%T' in assignment",
8257                        orig_type_left, orig_type_right);
8258         }
8259 }
8260
8261 static void semantic_integer_assign(binary_expression_t *expression)
8262 {
8263         expression_t *left            = expression->left;
8264         expression_t *right           = expression->right;
8265         type_t       *orig_type_left  = left->base.type;
8266         type_t       *orig_type_right = right->base.type;
8267
8268         if (!is_valid_assignment_lhs(left))
8269                 return;
8270
8271         type_t *type_left  = skip_typeref(orig_type_left);
8272         type_t *type_right = skip_typeref(orig_type_right);
8273
8274         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8275                 /* TODO: improve error message */
8276                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8277                         errorf(&expression->base.source_position,
8278                                "operation needs integer types");
8279                 }
8280                 return;
8281         }
8282
8283         /* combined instructions are tricky. We can't create an implicit cast on
8284          * the left side, because we need the uncasted form for the store.
8285          * The ast2firm pass has to know that left_type must be right_type
8286          * for the arithmetic operation and create a cast by itself */
8287         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8288         expression->right       = create_implicit_cast(right, arithmetic_type);
8289         expression->base.type   = type_left;
8290 }
8291
8292 static void semantic_shift_assign(binary_expression_t *expression)
8293 {
8294         expression_t *left           = expression->left;
8295
8296         if (!is_valid_assignment_lhs(left))
8297                 return;
8298
8299         if (!semantic_shift(expression))
8300                 return;
8301
8302         expression->base.type = skip_typeref(left->base.type);
8303 }
8304
8305 static void warn_logical_and_within_or(const expression_t *const expr)
8306 {
8307         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8308                 return;
8309         if (expr->base.parenthesized)
8310                 return;
8311         source_position_t const *const pos = &expr->base.source_position;
8312         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8313 }
8314
8315 /**
8316  * Check the semantic restrictions of a logical expression.
8317  */
8318 static void semantic_logical_op(binary_expression_t *expression)
8319 {
8320         /* §6.5.13:2  Each of the operands shall have scalar type.
8321          * §6.5.14:2  Each of the operands shall have scalar type. */
8322         semantic_condition(expression->left,   "left operand of logical operator");
8323         semantic_condition(expression->right, "right operand of logical operator");
8324         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8325                 warn_logical_and_within_or(expression->left);
8326                 warn_logical_and_within_or(expression->right);
8327         }
8328         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8329 }
8330
8331 /**
8332  * Check the semantic restrictions of a binary assign expression.
8333  */
8334 static void semantic_binexpr_assign(binary_expression_t *expression)
8335 {
8336         expression_t *left           = expression->left;
8337         type_t       *orig_type_left = left->base.type;
8338
8339         if (!is_valid_assignment_lhs(left))
8340                 return;
8341
8342         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8343         report_assign_error(error, orig_type_left, expression->right,
8344                         "assignment", &left->base.source_position);
8345         expression->right = create_implicit_cast(expression->right, orig_type_left);
8346         expression->base.type = orig_type_left;
8347 }
8348
8349 /**
8350  * Determine if the outermost operation (or parts thereof) of the given
8351  * expression has no effect in order to generate a warning about this fact.
8352  * Therefore in some cases this only examines some of the operands of the
8353  * expression (see comments in the function and examples below).
8354  * Examples:
8355  *   f() + 23;    // warning, because + has no effect
8356  *   x || f();    // no warning, because x controls execution of f()
8357  *   x ? y : f(); // warning, because y has no effect
8358  *   (void)x;     // no warning to be able to suppress the warning
8359  * This function can NOT be used for an "expression has definitely no effect"-
8360  * analysis. */
8361 static bool expression_has_effect(const expression_t *const expr)
8362 {
8363         switch (expr->kind) {
8364                 case EXPR_ERROR:                      return true; /* do NOT warn */
8365                 case EXPR_REFERENCE:                  return false;
8366                 case EXPR_ENUM_CONSTANT:              return false;
8367                 case EXPR_LABEL_ADDRESS:              return false;
8368
8369                 /* suppress the warning for microsoft __noop operations */
8370                 case EXPR_LITERAL_MS_NOOP:            return true;
8371                 case EXPR_LITERAL_BOOLEAN:
8372                 case EXPR_LITERAL_CHARACTER:
8373                 case EXPR_LITERAL_WIDE_CHARACTER:
8374                 case EXPR_LITERAL_INTEGER:
8375                 case EXPR_LITERAL_FLOATINGPOINT:
8376                 case EXPR_STRING_LITERAL:             return false;
8377                 case EXPR_WIDE_STRING_LITERAL:        return false;
8378
8379                 case EXPR_CALL: {
8380                         const call_expression_t *const call = &expr->call;
8381                         if (call->function->kind != EXPR_REFERENCE)
8382                                 return true;
8383
8384                         switch (call->function->reference.entity->function.btk) {
8385                                 /* FIXME: which builtins have no effect? */
8386                                 default:                      return true;
8387                         }
8388                 }
8389
8390                 /* Generate the warning if either the left or right hand side of a
8391                  * conditional expression has no effect */
8392                 case EXPR_CONDITIONAL: {
8393                         conditional_expression_t const *const cond = &expr->conditional;
8394                         expression_t             const *const t    = cond->true_expression;
8395                         return
8396                                 (t == NULL || expression_has_effect(t)) &&
8397                                 expression_has_effect(cond->false_expression);
8398                 }
8399
8400                 case EXPR_SELECT:                     return false;
8401                 case EXPR_ARRAY_ACCESS:               return false;
8402                 case EXPR_SIZEOF:                     return false;
8403                 case EXPR_CLASSIFY_TYPE:              return false;
8404                 case EXPR_ALIGNOF:                    return false;
8405
8406                 case EXPR_FUNCNAME:                   return false;
8407                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8408                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8409                 case EXPR_OFFSETOF:                   return false;
8410                 case EXPR_VA_START:                   return true;
8411                 case EXPR_VA_ARG:                     return true;
8412                 case EXPR_VA_COPY:                    return true;
8413                 case EXPR_STATEMENT:                  return true; // TODO
8414                 case EXPR_COMPOUND_LITERAL:           return false;
8415
8416                 case EXPR_UNARY_NEGATE:               return false;
8417                 case EXPR_UNARY_PLUS:                 return false;
8418                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8419                 case EXPR_UNARY_NOT:                  return false;
8420                 case EXPR_UNARY_DEREFERENCE:          return false;
8421                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8422                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8423                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8424                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8425                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8426
8427                 /* Treat void casts as if they have an effect in order to being able to
8428                  * suppress the warning */
8429                 case EXPR_UNARY_CAST: {
8430                         type_t *const type = skip_typeref(expr->base.type);
8431                         return is_type_void(type);
8432                 }
8433
8434                 case EXPR_UNARY_ASSUME:               return true;
8435                 case EXPR_UNARY_DELETE:               return true;
8436                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8437                 case EXPR_UNARY_THROW:                return true;
8438
8439                 case EXPR_BINARY_ADD:                 return false;
8440                 case EXPR_BINARY_SUB:                 return false;
8441                 case EXPR_BINARY_MUL:                 return false;
8442                 case EXPR_BINARY_DIV:                 return false;
8443                 case EXPR_BINARY_MOD:                 return false;
8444                 case EXPR_BINARY_EQUAL:               return false;
8445                 case EXPR_BINARY_NOTEQUAL:            return false;
8446                 case EXPR_BINARY_LESS:                return false;
8447                 case EXPR_BINARY_LESSEQUAL:           return false;
8448                 case EXPR_BINARY_GREATER:             return false;
8449                 case EXPR_BINARY_GREATEREQUAL:        return false;
8450                 case EXPR_BINARY_BITWISE_AND:         return false;
8451                 case EXPR_BINARY_BITWISE_OR:          return false;
8452                 case EXPR_BINARY_BITWISE_XOR:         return false;
8453                 case EXPR_BINARY_SHIFTLEFT:           return false;
8454                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8455                 case EXPR_BINARY_ASSIGN:              return true;
8456                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8457                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8458                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8459                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8460                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8461                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8462                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8463                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8464                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8465                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8466
8467                 /* Only examine the right hand side of && and ||, because the left hand
8468                  * side already has the effect of controlling the execution of the right
8469                  * hand side */
8470                 case EXPR_BINARY_LOGICAL_AND:
8471                 case EXPR_BINARY_LOGICAL_OR:
8472                 /* Only examine the right hand side of a comma expression, because the left
8473                  * hand side has a separate warning */
8474                 case EXPR_BINARY_COMMA:
8475                         return expression_has_effect(expr->binary.right);
8476
8477                 case EXPR_BINARY_ISGREATER:           return false;
8478                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8479                 case EXPR_BINARY_ISLESS:              return false;
8480                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8481                 case EXPR_BINARY_ISLESSGREATER:       return false;
8482                 case EXPR_BINARY_ISUNORDERED:         return false;
8483         }
8484
8485         internal_errorf(HERE, "unexpected expression");
8486 }
8487
8488 static void semantic_comma(binary_expression_t *expression)
8489 {
8490         const expression_t *const left = expression->left;
8491         if (!expression_has_effect(left)) {
8492                 source_position_t const *const pos = &left->base.source_position;
8493                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8494         }
8495         expression->base.type = expression->right->base.type;
8496 }
8497
8498 /**
8499  * @param prec_r precedence of the right operand
8500  */
8501 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8502 static expression_t *parse_##binexpression_type(expression_t *left)          \
8503 {                                                                            \
8504         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8505         binexpr->binary.left  = left;                                            \
8506         eat(token_kind);                                                         \
8507                                                                              \
8508         expression_t *right = parse_subexpression(prec_r);                       \
8509                                                                              \
8510         binexpr->binary.right = right;                                           \
8511         sfunc(&binexpr->binary);                                                 \
8512                                                                              \
8513         return binexpr;                                                          \
8514 }
8515
8516 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8517 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8518 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8519 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8520 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8521 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8522 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8523 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8524 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8525 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8526 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8527 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8528 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8529 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8530 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8531 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8532 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8533 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8534 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8535 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8536 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8537 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8538 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8539 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8540 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8541 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8542 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8543 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8544 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8545 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8546
8547
8548 static expression_t *parse_subexpression(precedence_t precedence)
8549 {
8550         expression_parser_function_t *parser
8551                 = &expression_parsers[token.kind];
8552         expression_t                 *left;
8553
8554         if (parser->parser != NULL) {
8555                 left = parser->parser();
8556         } else {
8557                 left = parse_primary_expression();
8558         }
8559         assert(left != NULL);
8560
8561         while (true) {
8562                 parser = &expression_parsers[token.kind];
8563                 if (parser->infix_parser == NULL)
8564                         break;
8565                 if (parser->infix_precedence < precedence)
8566                         break;
8567
8568                 left = parser->infix_parser(left);
8569
8570                 assert(left != NULL);
8571         }
8572
8573         return left;
8574 }
8575
8576 /**
8577  * Parse an expression.
8578  */
8579 static expression_t *parse_expression(void)
8580 {
8581         return parse_subexpression(PREC_EXPRESSION);
8582 }
8583
8584 /**
8585  * Register a parser for a prefix-like operator.
8586  *
8587  * @param parser      the parser function
8588  * @param token_kind  the token type of the prefix token
8589  */
8590 static void register_expression_parser(parse_expression_function parser,
8591                                        int token_kind)
8592 {
8593         expression_parser_function_t *entry = &expression_parsers[token_kind];
8594
8595         if (entry->parser != NULL) {
8596                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8597                 panic("trying to register multiple expression parsers for a token");
8598         }
8599         entry->parser = parser;
8600 }
8601
8602 /**
8603  * Register a parser for an infix operator with given precedence.
8604  *
8605  * @param parser      the parser function
8606  * @param token_kind  the token type of the infix operator
8607  * @param precedence  the precedence of the operator
8608  */
8609 static void register_infix_parser(parse_expression_infix_function parser,
8610                                   int token_kind, precedence_t precedence)
8611 {
8612         expression_parser_function_t *entry = &expression_parsers[token_kind];
8613
8614         if (entry->infix_parser != NULL) {
8615                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8616                 panic("trying to register multiple infix expression parsers for a "
8617                       "token");
8618         }
8619         entry->infix_parser     = parser;
8620         entry->infix_precedence = precedence;
8621 }
8622
8623 /**
8624  * Initialize the expression parsers.
8625  */
8626 static void init_expression_parsers(void)
8627 {
8628         memset(&expression_parsers, 0, sizeof(expression_parsers));
8629
8630         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8631         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8632         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8633         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8634         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8635         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8636         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8637         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8638         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8639         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8640         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8641         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8642         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8643         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8644         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8645         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8646         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8647         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8648         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8649         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8650         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8651         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8652         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8653         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8654         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8655         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8656         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8657         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8658         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8659         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8660         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8661         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8662         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8663         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8664         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8665         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8666         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8667
8668         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8669         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8670         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8671         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8672         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8673         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8674         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8675         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8676         register_expression_parser(parse_sizeof,                      T_sizeof);
8677         register_expression_parser(parse_alignof,                     T___alignof__);
8678         register_expression_parser(parse_extension,                   T___extension__);
8679         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8680         register_expression_parser(parse_delete,                      T_delete);
8681         register_expression_parser(parse_throw,                       T_throw);
8682 }
8683
8684 /**
8685  * Parse a asm statement arguments specification.
8686  */
8687 static asm_argument_t *parse_asm_arguments(bool is_out)
8688 {
8689         asm_argument_t  *result = NULL;
8690         asm_argument_t **anchor = &result;
8691
8692         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8693                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8694
8695                 if (next_if('[')) {
8696                         add_anchor_token(']');
8697                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8698                         rem_anchor_token(']');
8699                         expect(']');
8700                         if (!argument->symbol)
8701                                 return NULL;
8702                 }
8703
8704                 argument->constraints = parse_string_literals();
8705                 expect('(');
8706                 add_anchor_token(')');
8707                 expression_t *expression = parse_expression();
8708                 rem_anchor_token(')');
8709                 if (is_out) {
8710                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8711                          * change size or type representation (e.g. int -> long is ok, but
8712                          * int -> float is not) */
8713                         if (expression->kind == EXPR_UNARY_CAST) {
8714                                 type_t      *const type = expression->base.type;
8715                                 type_kind_t  const kind = type->kind;
8716                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8717                                         unsigned flags;
8718                                         unsigned size;
8719                                         if (kind == TYPE_ATOMIC) {
8720                                                 atomic_type_kind_t const akind = type->atomic.akind;
8721                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8722                                                 size  = get_atomic_type_size(akind);
8723                                         } else {
8724                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8725                                                 size  = get_type_size(type_void_ptr);
8726                                         }
8727
8728                                         do {
8729                                                 expression_t *const value      = expression->unary.value;
8730                                                 type_t       *const value_type = value->base.type;
8731                                                 type_kind_t   const value_kind = value_type->kind;
8732
8733                                                 unsigned value_flags;
8734                                                 unsigned value_size;
8735                                                 if (value_kind == TYPE_ATOMIC) {
8736                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8737                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8738                                                         value_size  = get_atomic_type_size(value_akind);
8739                                                 } else if (value_kind == TYPE_POINTER) {
8740                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8741                                                         value_size  = get_type_size(type_void_ptr);
8742                                                 } else {
8743                                                         break;
8744                                                 }
8745
8746                                                 if (value_flags != flags || value_size != size)
8747                                                         break;
8748
8749                                                 expression = value;
8750                                         } while (expression->kind == EXPR_UNARY_CAST);
8751                                 }
8752                         }
8753
8754                         if (!is_lvalue(expression)) {
8755                                 errorf(&expression->base.source_position,
8756                                        "asm output argument is not an lvalue");
8757                         }
8758
8759                         if (argument->constraints.begin[0] == '=')
8760                                 determine_lhs_ent(expression, NULL);
8761                         else
8762                                 mark_vars_read(expression, NULL);
8763                 } else {
8764                         mark_vars_read(expression, NULL);
8765                 }
8766                 argument->expression = expression;
8767                 expect(')');
8768
8769                 set_address_taken(expression, true);
8770
8771                 *anchor = argument;
8772                 anchor  = &argument->next;
8773
8774                 if (!next_if(','))
8775                         break;
8776         }
8777
8778         return result;
8779 }
8780
8781 /**
8782  * Parse a asm statement clobber specification.
8783  */
8784 static asm_clobber_t *parse_asm_clobbers(void)
8785 {
8786         asm_clobber_t *result  = NULL;
8787         asm_clobber_t **anchor = &result;
8788
8789         while (token.kind == T_STRING_LITERAL) {
8790                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8791                 clobber->clobber       = parse_string_literals();
8792
8793                 *anchor = clobber;
8794                 anchor  = &clobber->next;
8795
8796                 if (!next_if(','))
8797                         break;
8798         }
8799
8800         return result;
8801 }
8802
8803 /**
8804  * Parse an asm statement.
8805  */
8806 static statement_t *parse_asm_statement(void)
8807 {
8808         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8809         asm_statement_t *asm_statement = &statement->asms;
8810
8811         eat(T_asm);
8812
8813         if (next_if(T_volatile))
8814                 asm_statement->is_volatile = true;
8815
8816         expect('(');
8817         add_anchor_token(')');
8818         if (token.kind != T_STRING_LITERAL) {
8819                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8820                 goto end_of_asm;
8821         }
8822         asm_statement->asm_text = parse_string_literals();
8823
8824         add_anchor_token(':');
8825         if (!next_if(':')) {
8826                 rem_anchor_token(':');
8827                 goto end_of_asm;
8828         }
8829
8830         asm_statement->outputs = parse_asm_arguments(true);
8831         if (!next_if(':')) {
8832                 rem_anchor_token(':');
8833                 goto end_of_asm;
8834         }
8835
8836         asm_statement->inputs = parse_asm_arguments(false);
8837         if (!next_if(':')) {
8838                 rem_anchor_token(':');
8839                 goto end_of_asm;
8840         }
8841         rem_anchor_token(':');
8842
8843         asm_statement->clobbers = parse_asm_clobbers();
8844
8845 end_of_asm:
8846         rem_anchor_token(')');
8847         expect(')');
8848         expect(';');
8849
8850         if (asm_statement->outputs == NULL) {
8851                 /* GCC: An 'asm' instruction without any output operands will be treated
8852                  * identically to a volatile 'asm' instruction. */
8853                 asm_statement->is_volatile = true;
8854         }
8855
8856         return statement;
8857 }
8858
8859 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8860 {
8861         statement_t *inner_stmt;
8862         switch (token.kind) {
8863                 case '}':
8864                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8865                         inner_stmt = create_error_statement();
8866                         break;
8867
8868                 case ';':
8869                         if (label->kind == STATEMENT_LABEL) {
8870                                 /* Eat an empty statement here, to avoid the warning about an empty
8871                                  * statement after a label.  label:; is commonly used to have a label
8872                                  * before a closing brace. */
8873                                 inner_stmt = create_empty_statement();
8874                                 next_token();
8875                                 break;
8876                         }
8877                         /* FALLTHROUGH */
8878
8879                 default:
8880                         inner_stmt = parse_statement();
8881                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8882                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8883                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8884                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8885                         }
8886                         break;
8887         }
8888         return inner_stmt;
8889 }
8890
8891 /**
8892  * Parse a case statement.
8893  */
8894 static statement_t *parse_case_statement(void)
8895 {
8896         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8897         source_position_t *const pos       = &statement->base.source_position;
8898
8899         eat(T_case);
8900         add_anchor_token(':');
8901
8902         expression_t *expression = parse_expression();
8903         type_t *expression_type = expression->base.type;
8904         type_t *skipped         = skip_typeref(expression_type);
8905         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8906                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8907                        expression, expression_type);
8908         }
8909
8910         type_t *type = expression_type;
8911         if (current_switch != NULL) {
8912                 type_t *switch_type = current_switch->expression->base.type;
8913                 if (is_type_valid(switch_type)) {
8914                         expression = create_implicit_cast(expression, switch_type);
8915                 }
8916         }
8917
8918         statement->case_label.expression = expression;
8919         expression_classification_t const expr_class = is_constant_expression(expression);
8920         if (expr_class != EXPR_CLASS_CONSTANT) {
8921                 if (expr_class != EXPR_CLASS_ERROR) {
8922                         errorf(pos, "case label does not reduce to an integer constant");
8923                 }
8924                 statement->case_label.is_bad = true;
8925         } else {
8926                 long const val = fold_constant_to_int(expression);
8927                 statement->case_label.first_case = val;
8928                 statement->case_label.last_case  = val;
8929         }
8930
8931         if (GNU_MODE) {
8932                 if (next_if(T_DOTDOTDOT)) {
8933                         expression_t *end_range = parse_expression();
8934                         expression_type = expression->base.type;
8935                         skipped         = skip_typeref(expression_type);
8936                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8937                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8938                                            expression, expression_type);
8939                         }
8940
8941                         end_range = create_implicit_cast(end_range, type);
8942                         statement->case_label.end_range = end_range;
8943                         expression_classification_t const end_class = is_constant_expression(end_range);
8944                         if (end_class != EXPR_CLASS_CONSTANT) {
8945                                 if (end_class != EXPR_CLASS_ERROR) {
8946                                         errorf(pos, "case range does not reduce to an integer constant");
8947                                 }
8948                                 statement->case_label.is_bad = true;
8949                         } else {
8950                                 long const val = fold_constant_to_int(end_range);
8951                                 statement->case_label.last_case = val;
8952
8953                                 if (val < statement->case_label.first_case) {
8954                                         statement->case_label.is_empty_range = true;
8955                                         warningf(WARN_OTHER, pos, "empty range specified");
8956                                 }
8957                         }
8958                 }
8959         }
8960
8961         PUSH_PARENT(statement);
8962
8963         rem_anchor_token(':');
8964         expect(':');
8965
8966         if (current_switch != NULL) {
8967                 if (! statement->case_label.is_bad) {
8968                         /* Check for duplicate case values */
8969                         case_label_statement_t *c = &statement->case_label;
8970                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8971                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8972                                         continue;
8973
8974                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8975                                         continue;
8976
8977                                 errorf(pos, "duplicate case value (previously used %P)",
8978                                        &l->base.source_position);
8979                                 break;
8980                         }
8981                 }
8982                 /* link all cases into the switch statement */
8983                 if (current_switch->last_case == NULL) {
8984                         current_switch->first_case      = &statement->case_label;
8985                 } else {
8986                         current_switch->last_case->next = &statement->case_label;
8987                 }
8988                 current_switch->last_case = &statement->case_label;
8989         } else {
8990                 errorf(pos, "case label not within a switch statement");
8991         }
8992
8993         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8994
8995         POP_PARENT();
8996         return statement;
8997 }
8998
8999 /**
9000  * Parse a default statement.
9001  */
9002 static statement_t *parse_default_statement(void)
9003 {
9004         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
9005
9006         eat(T_default);
9007
9008         PUSH_PARENT(statement);
9009
9010         expect(':');
9011
9012         if (current_switch != NULL) {
9013                 const case_label_statement_t *def_label = current_switch->default_label;
9014                 if (def_label != NULL) {
9015                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9016                 } else {
9017                         current_switch->default_label = &statement->case_label;
9018
9019                         /* link all cases into the switch statement */
9020                         if (current_switch->last_case == NULL) {
9021                                 current_switch->first_case      = &statement->case_label;
9022                         } else {
9023                                 current_switch->last_case->next = &statement->case_label;
9024                         }
9025                         current_switch->last_case = &statement->case_label;
9026                 }
9027         } else {
9028                 errorf(&statement->base.source_position,
9029                         "'default' label not within a switch statement");
9030         }
9031
9032         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9033
9034         POP_PARENT();
9035         return statement;
9036 }
9037
9038 /**
9039  * Parse a label statement.
9040  */
9041 static statement_t *parse_label_statement(void)
9042 {
9043         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9044         label_t     *const label     = get_label();
9045         statement->label.label = label;
9046
9047         PUSH_PARENT(statement);
9048
9049         /* if statement is already set then the label is defined twice,
9050          * otherwise it was just mentioned in a goto/local label declaration so far
9051          */
9052         source_position_t const* const pos = &statement->base.source_position;
9053         if (label->statement != NULL) {
9054                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9055         } else {
9056                 label->base.source_position = *pos;
9057                 label->statement            = statement;
9058         }
9059
9060         eat(':');
9061
9062         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9063                 parse_attributes(NULL); // TODO process attributes
9064         }
9065
9066         statement->label.statement = parse_label_inner_statement(statement, "label");
9067
9068         /* remember the labels in a list for later checking */
9069         *label_anchor = &statement->label;
9070         label_anchor  = &statement->label.next;
9071
9072         POP_PARENT();
9073         return statement;
9074 }
9075
9076 static statement_t *parse_inner_statement(void)
9077 {
9078         statement_t *const stmt = parse_statement();
9079         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9080         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9081         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9082                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9083         }
9084         return stmt;
9085 }
9086
9087 /**
9088  * Parse an expression in parentheses and mark its variables as read.
9089  */
9090 static expression_t *parse_condition(void)
9091 {
9092         expect('(');
9093         add_anchor_token(')');
9094         expression_t *const expr = parse_expression();
9095         mark_vars_read(expr, NULL);
9096         rem_anchor_token(')');
9097         expect(')');
9098         return expr;
9099 }
9100
9101 /**
9102  * Parse an if statement.
9103  */
9104 static statement_t *parse_if(void)
9105 {
9106         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9107
9108         eat(T_if);
9109
9110         PUSH_PARENT(statement);
9111         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9112
9113         add_anchor_token(T_else);
9114
9115         expression_t *const expr = parse_condition();
9116         statement->ifs.condition = expr;
9117         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9118          *             scalar type. */
9119         semantic_condition(expr, "condition of 'if'-statment");
9120
9121         statement_t *const true_stmt = parse_inner_statement();
9122         statement->ifs.true_statement = true_stmt;
9123         rem_anchor_token(T_else);
9124
9125         if (true_stmt->kind == STATEMENT_EMPTY) {
9126                 warningf(WARN_EMPTY_BODY, HERE,
9127                         "suggest braces around empty body in an ‘if’ statement");
9128         }
9129
9130         if (next_if(T_else)) {
9131                 statement->ifs.false_statement = parse_inner_statement();
9132
9133                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9134                         warningf(WARN_EMPTY_BODY, HERE,
9135                                         "suggest braces around empty body in an ‘if’ statement");
9136                 }
9137         } else if (true_stmt->kind == STATEMENT_IF &&
9138                         true_stmt->ifs.false_statement != NULL) {
9139                 source_position_t const *const pos = &true_stmt->base.source_position;
9140                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9141         }
9142
9143         POP_SCOPE();
9144         POP_PARENT();
9145         return statement;
9146 }
9147
9148 /**
9149  * Check that all enums are handled in a switch.
9150  *
9151  * @param statement  the switch statement to check
9152  */
9153 static void check_enum_cases(const switch_statement_t *statement)
9154 {
9155         if (!is_warn_on(WARN_SWITCH_ENUM))
9156                 return;
9157         const type_t *type = skip_typeref(statement->expression->base.type);
9158         if (! is_type_enum(type))
9159                 return;
9160         const enum_type_t *enumt = &type->enumt;
9161
9162         /* if we have a default, no warnings */
9163         if (statement->default_label != NULL)
9164                 return;
9165
9166         /* FIXME: calculation of value should be done while parsing */
9167         /* TODO: quadratic algorithm here. Change to an n log n one */
9168         long            last_value = -1;
9169         const entity_t *entry      = enumt->enume->base.next;
9170         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9171              entry = entry->base.next) {
9172                 const expression_t *expression = entry->enum_value.value;
9173                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9174                 bool                found      = false;
9175                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9176                         if (l->expression == NULL)
9177                                 continue;
9178                         if (l->first_case <= value && value <= l->last_case) {
9179                                 found = true;
9180                                 break;
9181                         }
9182                 }
9183                 if (!found) {
9184                         source_position_t const *const pos = &statement->base.source_position;
9185                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9186                 }
9187                 last_value = value;
9188         }
9189 }
9190
9191 /**
9192  * Parse a switch statement.
9193  */
9194 static statement_t *parse_switch(void)
9195 {
9196         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9197
9198         eat(T_switch);
9199
9200         PUSH_PARENT(statement);
9201         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9202
9203         expression_t *const expr = parse_condition();
9204         type_t       *      type = skip_typeref(expr->base.type);
9205         if (is_type_integer(type)) {
9206                 type = promote_integer(type);
9207                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9208                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9209                 }
9210         } else if (is_type_valid(type)) {
9211                 errorf(&expr->base.source_position,
9212                        "switch quantity is not an integer, but '%T'", type);
9213                 type = type_error_type;
9214         }
9215         statement->switchs.expression = create_implicit_cast(expr, type);
9216
9217         switch_statement_t *rem = current_switch;
9218         current_switch          = &statement->switchs;
9219         statement->switchs.body = parse_inner_statement();
9220         current_switch          = rem;
9221
9222         if (statement->switchs.default_label == NULL) {
9223                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9224         }
9225         check_enum_cases(&statement->switchs);
9226
9227         POP_SCOPE();
9228         POP_PARENT();
9229         return statement;
9230 }
9231
9232 static statement_t *parse_loop_body(statement_t *const loop)
9233 {
9234         statement_t *const rem = current_loop;
9235         current_loop = loop;
9236
9237         statement_t *const body = parse_inner_statement();
9238
9239         current_loop = rem;
9240         return body;
9241 }
9242
9243 /**
9244  * Parse a while statement.
9245  */
9246 static statement_t *parse_while(void)
9247 {
9248         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9249
9250         eat(T_while);
9251
9252         PUSH_PARENT(statement);
9253         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9254
9255         expression_t *const cond = parse_condition();
9256         statement->whiles.condition = cond;
9257         /* §6.8.5:2    The controlling expression of an iteration statement shall
9258          *             have scalar type. */
9259         semantic_condition(cond, "condition of 'while'-statement");
9260
9261         statement->whiles.body = parse_loop_body(statement);
9262
9263         POP_SCOPE();
9264         POP_PARENT();
9265         return statement;
9266 }
9267
9268 /**
9269  * Parse a do statement.
9270  */
9271 static statement_t *parse_do(void)
9272 {
9273         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9274
9275         eat(T_do);
9276
9277         PUSH_PARENT(statement);
9278         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9279
9280         add_anchor_token(T_while);
9281         statement->do_while.body = parse_loop_body(statement);
9282         rem_anchor_token(T_while);
9283
9284         expect(T_while);
9285         expression_t *const cond = parse_condition();
9286         statement->do_while.condition = cond;
9287         /* §6.8.5:2    The controlling expression of an iteration statement shall
9288          *             have scalar type. */
9289         semantic_condition(cond, "condition of 'do-while'-statement");
9290         expect(';');
9291
9292         POP_SCOPE();
9293         POP_PARENT();
9294         return statement;
9295 }
9296
9297 /**
9298  * Parse a for statement.
9299  */
9300 static statement_t *parse_for(void)
9301 {
9302         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9303
9304         eat(T_for);
9305
9306         PUSH_PARENT(statement);
9307         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9308
9309         expect('(');
9310         add_anchor_token(')');
9311
9312         PUSH_EXTENSION();
9313
9314         if (next_if(';')) {
9315         } else if (is_declaration_specifier(&token)) {
9316                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9317         } else {
9318                 add_anchor_token(';');
9319                 expression_t *const init = parse_expression();
9320                 statement->fors.initialisation = init;
9321                 mark_vars_read(init, ENT_ANY);
9322                 if (!expression_has_effect(init)) {
9323                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9324                 }
9325                 rem_anchor_token(';');
9326                 expect(';');
9327         }
9328
9329         POP_EXTENSION();
9330
9331         if (token.kind != ';') {
9332                 add_anchor_token(';');
9333                 expression_t *const cond = parse_expression();
9334                 statement->fors.condition = cond;
9335                 /* §6.8.5:2    The controlling expression of an iteration statement
9336                  *             shall have scalar type. */
9337                 semantic_condition(cond, "condition of 'for'-statement");
9338                 mark_vars_read(cond, NULL);
9339                 rem_anchor_token(';');
9340         }
9341         expect(';');
9342         if (token.kind != ')') {
9343                 expression_t *const step = parse_expression();
9344                 statement->fors.step = step;
9345                 mark_vars_read(step, ENT_ANY);
9346                 if (!expression_has_effect(step)) {
9347                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9348                 }
9349         }
9350         rem_anchor_token(')');
9351         expect(')');
9352         statement->fors.body = parse_loop_body(statement);
9353
9354         POP_SCOPE();
9355         POP_PARENT();
9356         return statement;
9357 }
9358
9359 /**
9360  * Parse a goto statement.
9361  */
9362 static statement_t *parse_goto(void)
9363 {
9364         statement_t *statement;
9365         if (GNU_MODE && look_ahead(1)->kind == '*') {
9366                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9367                 eat(T_goto);
9368                 eat('*');
9369
9370                 expression_t *expression = parse_expression();
9371                 mark_vars_read(expression, NULL);
9372
9373                 /* Argh: although documentation says the expression must be of type void*,
9374                  * gcc accepts anything that can be casted into void* without error */
9375                 type_t *type = expression->base.type;
9376
9377                 if (type != type_error_type) {
9378                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9379                                 errorf(&expression->base.source_position,
9380                                         "cannot convert to a pointer type");
9381                         } else if (type != type_void_ptr) {
9382                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9383                         }
9384                         expression = create_implicit_cast(expression, type_void_ptr);
9385                 }
9386
9387                 statement->computed_goto.expression = expression;
9388         } else {
9389                 statement = allocate_statement_zero(STATEMENT_GOTO);
9390                 eat(T_goto);
9391                 if (token.kind == T_IDENTIFIER) {
9392                         label_t *const label = get_label();
9393                         label->used            = true;
9394                         statement->gotos.label = label;
9395
9396                         /* remember the goto's in a list for later checking */
9397                         *goto_anchor = &statement->gotos;
9398                         goto_anchor  = &statement->gotos.next;
9399                 } else {
9400                         if (GNU_MODE)
9401                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9402                         else
9403                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9404                         eat_until_anchor();
9405                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9406                 }
9407         }
9408
9409         expect(';');
9410         return statement;
9411 }
9412
9413 /**
9414  * Parse a continue statement.
9415  */
9416 static statement_t *parse_continue(void)
9417 {
9418         if (current_loop == NULL) {
9419                 errorf(HERE, "continue statement not within loop");
9420         }
9421
9422         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9423
9424         eat(T_continue);
9425         expect(';');
9426         return statement;
9427 }
9428
9429 /**
9430  * Parse a break statement.
9431  */
9432 static statement_t *parse_break(void)
9433 {
9434         if (current_switch == NULL && current_loop == NULL) {
9435                 errorf(HERE, "break statement not within loop or switch");
9436         }
9437
9438         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9439
9440         eat(T_break);
9441         expect(';');
9442         return statement;
9443 }
9444
9445 /**
9446  * Parse a __leave statement.
9447  */
9448 static statement_t *parse_leave_statement(void)
9449 {
9450         if (current_try == NULL) {
9451                 errorf(HERE, "__leave statement not within __try");
9452         }
9453
9454         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9455
9456         eat(T___leave);
9457         expect(';');
9458         return statement;
9459 }
9460
9461 /**
9462  * Check if a given entity represents a local variable.
9463  */
9464 static bool is_local_variable(const entity_t *entity)
9465 {
9466         if (entity->kind != ENTITY_VARIABLE)
9467                 return false;
9468
9469         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9470         case STORAGE_CLASS_AUTO:
9471         case STORAGE_CLASS_REGISTER: {
9472                 const type_t *type = skip_typeref(entity->declaration.type);
9473                 if (is_type_function(type)) {
9474                         return false;
9475                 } else {
9476                         return true;
9477                 }
9478         }
9479         default:
9480                 return false;
9481         }
9482 }
9483
9484 /**
9485  * Check if a given expression represents a local variable.
9486  */
9487 static bool expression_is_local_variable(const expression_t *expression)
9488 {
9489         if (expression->base.kind != EXPR_REFERENCE) {
9490                 return false;
9491         }
9492         const entity_t *entity = expression->reference.entity;
9493         return is_local_variable(entity);
9494 }
9495
9496 /**
9497  * Check if a given expression represents a local variable and
9498  * return its declaration then, else return NULL.
9499  */
9500 entity_t *expression_is_variable(const expression_t *expression)
9501 {
9502         if (expression->base.kind != EXPR_REFERENCE) {
9503                 return NULL;
9504         }
9505         entity_t *entity = expression->reference.entity;
9506         if (entity->kind != ENTITY_VARIABLE)
9507                 return NULL;
9508
9509         return entity;
9510 }
9511
9512 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9513 {
9514         if (c_mode & _CXX || strict_mode) {
9515                 errorf(pos, msg);
9516         } else {
9517                 warningf(WARN_OTHER, pos, msg);
9518         }
9519 }
9520
9521 /**
9522  * Parse a return statement.
9523  */
9524 static statement_t *parse_return(void)
9525 {
9526         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9527         eat(T_return);
9528
9529         expression_t *return_value = NULL;
9530         if (token.kind != ';') {
9531                 return_value = parse_expression();
9532                 mark_vars_read(return_value, NULL);
9533         }
9534
9535         const type_t *const func_type = skip_typeref(current_function->base.type);
9536         assert(is_type_function(func_type));
9537         type_t *const return_type = skip_typeref(func_type->function.return_type);
9538
9539         source_position_t const *const pos = &statement->base.source_position;
9540         if (return_value != NULL) {
9541                 type_t *return_value_type = skip_typeref(return_value->base.type);
9542
9543                 if (is_type_void(return_type)) {
9544                         if (!is_type_void(return_value_type)) {
9545                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9546                                 /* Only warn in C mode, because GCC does the same */
9547                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9548                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9549                                 /* Only warn in C mode, because GCC does the same */
9550                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9551                         }
9552                 } else {
9553                         assign_error_t error = semantic_assign(return_type, return_value);
9554                         report_assign_error(error, return_type, return_value, "'return'",
9555                                             pos);
9556                 }
9557                 return_value = create_implicit_cast(return_value, return_type);
9558                 /* check for returning address of a local var */
9559                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9560                         const expression_t *expression = return_value->unary.value;
9561                         if (expression_is_local_variable(expression)) {
9562                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9563                         }
9564                 }
9565         } else if (!is_type_void(return_type)) {
9566                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9567                 err_or_warn(pos, "'return' without value, in function returning non-void");
9568         }
9569         statement->returns.value = return_value;
9570
9571         expect(';');
9572         return statement;
9573 }
9574
9575 /**
9576  * Parse a declaration statement.
9577  */
9578 static statement_t *parse_declaration_statement(void)
9579 {
9580         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9581
9582         entity_t *before = current_scope->last_entity;
9583         if (GNU_MODE) {
9584                 parse_external_declaration();
9585         } else {
9586                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9587         }
9588
9589         declaration_statement_t *const decl  = &statement->declaration;
9590         entity_t                *const begin =
9591                 before != NULL ? before->base.next : current_scope->entities;
9592         decl->declarations_begin = begin;
9593         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9594
9595         return statement;
9596 }
9597
9598 /**
9599  * Parse an expression statement, ie. expr ';'.
9600  */
9601 static statement_t *parse_expression_statement(void)
9602 {
9603         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9604
9605         expression_t *const expr         = parse_expression();
9606         statement->expression.expression = expr;
9607         mark_vars_read(expr, ENT_ANY);
9608
9609         expect(';');
9610         return statement;
9611 }
9612
9613 /**
9614  * Parse a microsoft __try { } __finally { } or
9615  * __try{ } __except() { }
9616  */
9617 static statement_t *parse_ms_try_statment(void)
9618 {
9619         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9620         eat(T___try);
9621
9622         PUSH_PARENT(statement);
9623
9624         ms_try_statement_t *rem = current_try;
9625         current_try = &statement->ms_try;
9626         statement->ms_try.try_statement = parse_compound_statement(false);
9627         current_try = rem;
9628
9629         POP_PARENT();
9630
9631         if (next_if(T___except)) {
9632                 expression_t *const expr = parse_condition();
9633                 type_t       *      type = skip_typeref(expr->base.type);
9634                 if (is_type_integer(type)) {
9635                         type = promote_integer(type);
9636                 } else if (is_type_valid(type)) {
9637                         errorf(&expr->base.source_position,
9638                                "__expect expression is not an integer, but '%T'", type);
9639                         type = type_error_type;
9640                 }
9641                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9642         } else if (!next_if(T__finally)) {
9643                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9644         }
9645         statement->ms_try.final_statement = parse_compound_statement(false);
9646         return statement;
9647 }
9648
9649 static statement_t *parse_empty_statement(void)
9650 {
9651         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9652         statement_t *const statement = create_empty_statement();
9653         eat(';');
9654         return statement;
9655 }
9656
9657 static statement_t *parse_local_label_declaration(void)
9658 {
9659         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9660
9661         eat(T___label__);
9662
9663         entity_t *begin   = NULL;
9664         entity_t *end     = NULL;
9665         entity_t **anchor = &begin;
9666         do {
9667                 source_position_t pos;
9668                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9669                 if (!symbol)
9670                         goto end_error;
9671
9672                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9673                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9674                         source_position_t const *const ppos = &entity->base.source_position;
9675                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9676                 } else {
9677                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9678                         entity->base.parent_scope = current_scope;
9679
9680                         *anchor = entity;
9681                         anchor  = &entity->base.next;
9682                         end     = entity;
9683
9684                         environment_push(entity);
9685                 }
9686         } while (next_if(','));
9687         expect(';');
9688 end_error:
9689         statement->declaration.declarations_begin = begin;
9690         statement->declaration.declarations_end   = end;
9691         return statement;
9692 }
9693
9694 static void parse_namespace_definition(void)
9695 {
9696         eat(T_namespace);
9697
9698         entity_t *entity = NULL;
9699         symbol_t *symbol = NULL;
9700
9701         if (token.kind == T_IDENTIFIER) {
9702                 symbol = token.base.symbol;
9703                 next_token();
9704
9705                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9706                 if (entity != NULL
9707                                 && entity->kind != ENTITY_NAMESPACE
9708                                 && entity->base.parent_scope == current_scope) {
9709                         if (is_entity_valid(entity)) {
9710                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9711                         }
9712                         entity = NULL;
9713                 }
9714         }
9715
9716         if (entity == NULL) {
9717                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9718                 entity->base.parent_scope = current_scope;
9719         }
9720
9721         if (token.kind == '=') {
9722                 /* TODO: parse namespace alias */
9723                 panic("namespace alias definition not supported yet");
9724         }
9725
9726         environment_push(entity);
9727         append_entity(current_scope, entity);
9728
9729         PUSH_SCOPE(&entity->namespacee.members);
9730         PUSH_CURRENT_ENTITY(entity);
9731
9732         add_anchor_token('}');
9733         expect('{');
9734         parse_externals();
9735         rem_anchor_token('}');
9736         expect('}');
9737
9738         POP_CURRENT_ENTITY();
9739         POP_SCOPE();
9740 }
9741
9742 /**
9743  * Parse a statement.
9744  * There's also parse_statement() which additionally checks for
9745  * "statement has no effect" warnings
9746  */
9747 static statement_t *intern_parse_statement(void)
9748 {
9749         /* declaration or statement */
9750         statement_t *statement;
9751         switch (token.kind) {
9752         case T_IDENTIFIER: {
9753                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9754                 if (la1_type == ':') {
9755                         statement = parse_label_statement();
9756                 } else if (is_typedef_symbol(token.base.symbol)) {
9757                         statement = parse_declaration_statement();
9758                 } else {
9759                         /* it's an identifier, the grammar says this must be an
9760                          * expression statement. However it is common that users mistype
9761                          * declaration types, so we guess a bit here to improve robustness
9762                          * for incorrect programs */
9763                         switch (la1_type) {
9764                         case '&':
9765                         case '*':
9766                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9767                         default:
9768                                         statement = parse_expression_statement();
9769                                 } else {
9770                         DECLARATION_START
9771                         case T_IDENTIFIER:
9772                                         statement = parse_declaration_statement();
9773                                 }
9774                                 break;
9775                         }
9776                 }
9777                 break;
9778         }
9779
9780         case T___extension__: {
9781                 /* This can be a prefix to a declaration or an expression statement.
9782                  * We simply eat it now and parse the rest with tail recursion. */
9783                 PUSH_EXTENSION();
9784                 statement = intern_parse_statement();
9785                 POP_EXTENSION();
9786                 break;
9787         }
9788
9789         DECLARATION_START
9790                 statement = parse_declaration_statement();
9791                 break;
9792
9793         case T___label__:
9794                 statement = parse_local_label_declaration();
9795                 break;
9796
9797         case ';':         statement = parse_empty_statement();         break;
9798         case '{':         statement = parse_compound_statement(false); break;
9799         case T___leave:   statement = parse_leave_statement();         break;
9800         case T___try:     statement = parse_ms_try_statment();         break;
9801         case T_asm:       statement = parse_asm_statement();           break;
9802         case T_break:     statement = parse_break();                   break;
9803         case T_case:      statement = parse_case_statement();          break;
9804         case T_continue:  statement = parse_continue();                break;
9805         case T_default:   statement = parse_default_statement();       break;
9806         case T_do:        statement = parse_do();                      break;
9807         case T_for:       statement = parse_for();                     break;
9808         case T_goto:      statement = parse_goto();                    break;
9809         case T_if:        statement = parse_if();                      break;
9810         case T_return:    statement = parse_return();                  break;
9811         case T_switch:    statement = parse_switch();                  break;
9812         case T_while:     statement = parse_while();                   break;
9813
9814         EXPRESSION_START
9815                 statement = parse_expression_statement();
9816                 break;
9817
9818         default:
9819                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9820                 statement = create_error_statement();
9821                 eat_until_anchor();
9822                 break;
9823         }
9824
9825         return statement;
9826 }
9827
9828 /**
9829  * parse a statement and emits "statement has no effect" warning if needed
9830  * (This is really a wrapper around intern_parse_statement with check for 1
9831  *  single warning. It is needed, because for statement expressions we have
9832  *  to avoid the warning on the last statement)
9833  */
9834 static statement_t *parse_statement(void)
9835 {
9836         statement_t *statement = intern_parse_statement();
9837
9838         if (statement->kind == STATEMENT_EXPRESSION) {
9839                 expression_t *expression = statement->expression.expression;
9840                 if (!expression_has_effect(expression)) {
9841                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9842                 }
9843         }
9844
9845         return statement;
9846 }
9847
9848 /**
9849  * Parse a compound statement.
9850  */
9851 static statement_t *parse_compound_statement(bool inside_expression_statement)
9852 {
9853         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9854
9855         PUSH_PARENT(statement);
9856         PUSH_SCOPE(&statement->compound.scope);
9857
9858         eat('{');
9859         add_anchor_token('}');
9860         /* tokens, which can start a statement */
9861         /* TODO MS, __builtin_FOO */
9862         add_anchor_token('!');
9863         add_anchor_token('&');
9864         add_anchor_token('(');
9865         add_anchor_token('*');
9866         add_anchor_token('+');
9867         add_anchor_token('-');
9868         add_anchor_token(';');
9869         add_anchor_token('{');
9870         add_anchor_token('~');
9871         add_anchor_token(T_CHARACTER_CONSTANT);
9872         add_anchor_token(T_COLONCOLON);
9873         add_anchor_token(T_FLOATINGPOINT);
9874         add_anchor_token(T_IDENTIFIER);
9875         add_anchor_token(T_INTEGER);
9876         add_anchor_token(T_MINUSMINUS);
9877         add_anchor_token(T_PLUSPLUS);
9878         add_anchor_token(T_STRING_LITERAL);
9879         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9880         add_anchor_token(T_WIDE_STRING_LITERAL);
9881         add_anchor_token(T__Bool);
9882         add_anchor_token(T__Complex);
9883         add_anchor_token(T__Imaginary);
9884         add_anchor_token(T___FUNCTION__);
9885         add_anchor_token(T___PRETTY_FUNCTION__);
9886         add_anchor_token(T___alignof__);
9887         add_anchor_token(T___attribute__);
9888         add_anchor_token(T___builtin_va_start);
9889         add_anchor_token(T___extension__);
9890         add_anchor_token(T___func__);
9891         add_anchor_token(T___imag__);
9892         add_anchor_token(T___label__);
9893         add_anchor_token(T___real__);
9894         add_anchor_token(T___thread);
9895         add_anchor_token(T_asm);
9896         add_anchor_token(T_auto);
9897         add_anchor_token(T_bool);
9898         add_anchor_token(T_break);
9899         add_anchor_token(T_case);
9900         add_anchor_token(T_char);
9901         add_anchor_token(T_class);
9902         add_anchor_token(T_const);
9903         add_anchor_token(T_const_cast);
9904         add_anchor_token(T_continue);
9905         add_anchor_token(T_default);
9906         add_anchor_token(T_delete);
9907         add_anchor_token(T_double);
9908         add_anchor_token(T_do);
9909         add_anchor_token(T_dynamic_cast);
9910         add_anchor_token(T_enum);
9911         add_anchor_token(T_extern);
9912         add_anchor_token(T_false);
9913         add_anchor_token(T_float);
9914         add_anchor_token(T_for);
9915         add_anchor_token(T_goto);
9916         add_anchor_token(T_if);
9917         add_anchor_token(T_inline);
9918         add_anchor_token(T_int);
9919         add_anchor_token(T_long);
9920         add_anchor_token(T_new);
9921         add_anchor_token(T_operator);
9922         add_anchor_token(T_register);
9923         add_anchor_token(T_reinterpret_cast);
9924         add_anchor_token(T_restrict);
9925         add_anchor_token(T_return);
9926         add_anchor_token(T_short);
9927         add_anchor_token(T_signed);
9928         add_anchor_token(T_sizeof);
9929         add_anchor_token(T_static);
9930         add_anchor_token(T_static_cast);
9931         add_anchor_token(T_struct);
9932         add_anchor_token(T_switch);
9933         add_anchor_token(T_template);
9934         add_anchor_token(T_this);
9935         add_anchor_token(T_throw);
9936         add_anchor_token(T_true);
9937         add_anchor_token(T_try);
9938         add_anchor_token(T_typedef);
9939         add_anchor_token(T_typeid);
9940         add_anchor_token(T_typename);
9941         add_anchor_token(T_typeof);
9942         add_anchor_token(T_union);
9943         add_anchor_token(T_unsigned);
9944         add_anchor_token(T_using);
9945         add_anchor_token(T_void);
9946         add_anchor_token(T_volatile);
9947         add_anchor_token(T_wchar_t);
9948         add_anchor_token(T_while);
9949
9950         statement_t **anchor            = &statement->compound.statements;
9951         bool          only_decls_so_far = true;
9952         while (token.kind != '}' && token.kind != T_EOF) {
9953                 statement_t *sub_statement = intern_parse_statement();
9954                 if (sub_statement->kind == STATEMENT_ERROR) {
9955                         break;
9956                 }
9957
9958                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9959                         only_decls_so_far = false;
9960                 } else if (!only_decls_so_far) {
9961                         source_position_t const *const pos = &sub_statement->base.source_position;
9962                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9963                 }
9964
9965                 *anchor = sub_statement;
9966                 anchor  = &sub_statement->base.next;
9967         }
9968         expect('}');
9969
9970         /* look over all statements again to produce no effect warnings */
9971         if (is_warn_on(WARN_UNUSED_VALUE)) {
9972                 statement_t *sub_statement = statement->compound.statements;
9973                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9974                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9975                                 continue;
9976                         /* don't emit a warning for the last expression in an expression
9977                          * statement as it has always an effect */
9978                         if (inside_expression_statement && sub_statement->base.next == NULL)
9979                                 continue;
9980
9981                         expression_t *expression = sub_statement->expression.expression;
9982                         if (!expression_has_effect(expression)) {
9983                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9984                         }
9985                 }
9986         }
9987
9988         rem_anchor_token(T_while);
9989         rem_anchor_token(T_wchar_t);
9990         rem_anchor_token(T_volatile);
9991         rem_anchor_token(T_void);
9992         rem_anchor_token(T_using);
9993         rem_anchor_token(T_unsigned);
9994         rem_anchor_token(T_union);
9995         rem_anchor_token(T_typeof);
9996         rem_anchor_token(T_typename);
9997         rem_anchor_token(T_typeid);
9998         rem_anchor_token(T_typedef);
9999         rem_anchor_token(T_try);
10000         rem_anchor_token(T_true);
10001         rem_anchor_token(T_throw);
10002         rem_anchor_token(T_this);
10003         rem_anchor_token(T_template);
10004         rem_anchor_token(T_switch);
10005         rem_anchor_token(T_struct);
10006         rem_anchor_token(T_static_cast);
10007         rem_anchor_token(T_static);
10008         rem_anchor_token(T_sizeof);
10009         rem_anchor_token(T_signed);
10010         rem_anchor_token(T_short);
10011         rem_anchor_token(T_return);
10012         rem_anchor_token(T_restrict);
10013         rem_anchor_token(T_reinterpret_cast);
10014         rem_anchor_token(T_register);
10015         rem_anchor_token(T_operator);
10016         rem_anchor_token(T_new);
10017         rem_anchor_token(T_long);
10018         rem_anchor_token(T_int);
10019         rem_anchor_token(T_inline);
10020         rem_anchor_token(T_if);
10021         rem_anchor_token(T_goto);
10022         rem_anchor_token(T_for);
10023         rem_anchor_token(T_float);
10024         rem_anchor_token(T_false);
10025         rem_anchor_token(T_extern);
10026         rem_anchor_token(T_enum);
10027         rem_anchor_token(T_dynamic_cast);
10028         rem_anchor_token(T_do);
10029         rem_anchor_token(T_double);
10030         rem_anchor_token(T_delete);
10031         rem_anchor_token(T_default);
10032         rem_anchor_token(T_continue);
10033         rem_anchor_token(T_const_cast);
10034         rem_anchor_token(T_const);
10035         rem_anchor_token(T_class);
10036         rem_anchor_token(T_char);
10037         rem_anchor_token(T_case);
10038         rem_anchor_token(T_break);
10039         rem_anchor_token(T_bool);
10040         rem_anchor_token(T_auto);
10041         rem_anchor_token(T_asm);
10042         rem_anchor_token(T___thread);
10043         rem_anchor_token(T___real__);
10044         rem_anchor_token(T___label__);
10045         rem_anchor_token(T___imag__);
10046         rem_anchor_token(T___func__);
10047         rem_anchor_token(T___extension__);
10048         rem_anchor_token(T___builtin_va_start);
10049         rem_anchor_token(T___attribute__);
10050         rem_anchor_token(T___alignof__);
10051         rem_anchor_token(T___PRETTY_FUNCTION__);
10052         rem_anchor_token(T___FUNCTION__);
10053         rem_anchor_token(T__Imaginary);
10054         rem_anchor_token(T__Complex);
10055         rem_anchor_token(T__Bool);
10056         rem_anchor_token(T_WIDE_STRING_LITERAL);
10057         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10058         rem_anchor_token(T_STRING_LITERAL);
10059         rem_anchor_token(T_PLUSPLUS);
10060         rem_anchor_token(T_MINUSMINUS);
10061         rem_anchor_token(T_INTEGER);
10062         rem_anchor_token(T_IDENTIFIER);
10063         rem_anchor_token(T_FLOATINGPOINT);
10064         rem_anchor_token(T_COLONCOLON);
10065         rem_anchor_token(T_CHARACTER_CONSTANT);
10066         rem_anchor_token('~');
10067         rem_anchor_token('{');
10068         rem_anchor_token(';');
10069         rem_anchor_token('-');
10070         rem_anchor_token('+');
10071         rem_anchor_token('*');
10072         rem_anchor_token('(');
10073         rem_anchor_token('&');
10074         rem_anchor_token('!');
10075         rem_anchor_token('}');
10076
10077         POP_SCOPE();
10078         POP_PARENT();
10079         return statement;
10080 }
10081
10082 /**
10083  * Check for unused global static functions and variables
10084  */
10085 static void check_unused_globals(void)
10086 {
10087         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10088                 return;
10089
10090         for (const entity_t *entity = file_scope->entities; entity != NULL;
10091              entity = entity->base.next) {
10092                 if (!is_declaration(entity))
10093                         continue;
10094
10095                 const declaration_t *declaration = &entity->declaration;
10096                 if (declaration->used                  ||
10097                     declaration->modifiers & DM_UNUSED ||
10098                     declaration->modifiers & DM_USED   ||
10099                     declaration->storage_class != STORAGE_CLASS_STATIC)
10100                         continue;
10101
10102                 warning_t   why;
10103                 char const *s;
10104                 if (entity->kind == ENTITY_FUNCTION) {
10105                         /* inhibit warning for static inline functions */
10106                         if (entity->function.is_inline)
10107                                 continue;
10108
10109                         why = WARN_UNUSED_FUNCTION;
10110                         s   = entity->function.statement != NULL ? "defined" : "declared";
10111                 } else {
10112                         why = WARN_UNUSED_VARIABLE;
10113                         s   = "defined";
10114                 }
10115
10116                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10117         }
10118 }
10119
10120 static void parse_global_asm(void)
10121 {
10122         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10123
10124         eat(T_asm);
10125         add_anchor_token(';');
10126         add_anchor_token(')');
10127         add_anchor_token(T_STRING_LITERAL);
10128         expect('(');
10129
10130         rem_anchor_token(T_STRING_LITERAL);
10131         statement->asms.asm_text = parse_string_literals();
10132         statement->base.next     = unit->global_asm;
10133         unit->global_asm         = statement;
10134
10135         rem_anchor_token(')');
10136         expect(')');
10137         rem_anchor_token(';');
10138         expect(';');
10139 }
10140
10141 static void parse_linkage_specification(void)
10142 {
10143         eat(T_extern);
10144
10145         source_position_t const pos     = *HERE;
10146         char const       *const linkage = parse_string_literals().begin;
10147
10148         linkage_kind_t old_linkage = current_linkage;
10149         linkage_kind_t new_linkage;
10150         if (streq(linkage, "C")) {
10151                 new_linkage = LINKAGE_C;
10152         } else if (streq(linkage, "C++")) {
10153                 new_linkage = LINKAGE_CXX;
10154         } else {
10155                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10156                 new_linkage = LINKAGE_C;
10157         }
10158         current_linkage = new_linkage;
10159
10160         if (next_if('{')) {
10161                 parse_externals();
10162                 expect('}');
10163         } else {
10164                 parse_external();
10165         }
10166
10167         assert(current_linkage == new_linkage);
10168         current_linkage = old_linkage;
10169 }
10170
10171 static void parse_external(void)
10172 {
10173         switch (token.kind) {
10174                 case T_extern:
10175                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10176                                 parse_linkage_specification();
10177                         } else {
10178                 DECLARATION_START_NO_EXTERN
10179                 case T_IDENTIFIER:
10180                 case T___extension__:
10181                 /* tokens below are for implicit int */
10182                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10183                               implicit int) */
10184                 case '*':  /* * x; -> int* x; */
10185                 case '(':  /* (x); -> int (x); */
10186                                 PUSH_EXTENSION();
10187                                 parse_external_declaration();
10188                                 POP_EXTENSION();
10189                         }
10190                         return;
10191
10192                 case T_asm:
10193                         parse_global_asm();
10194                         return;
10195
10196                 case T_namespace:
10197                         parse_namespace_definition();
10198                         return;
10199
10200                 case ';':
10201                         if (!strict_mode) {
10202                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10203                                 next_token();
10204                                 return;
10205                         }
10206                         /* FALLTHROUGH */
10207
10208                 default:
10209                         errorf(HERE, "stray %K outside of function", &token);
10210                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10211                                 eat_until_matching_token(token.kind);
10212                         next_token();
10213                         return;
10214         }
10215 }
10216
10217 static void parse_externals(void)
10218 {
10219         add_anchor_token('}');
10220         add_anchor_token(T_EOF);
10221
10222 #ifndef NDEBUG
10223         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10224         unsigned short token_anchor_copy[T_LAST_TOKEN];
10225         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10226 #endif
10227
10228         while (token.kind != T_EOF && token.kind != '}') {
10229 #ifndef NDEBUG
10230                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10231                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10232                         if (count != 0) {
10233                                 /* the anchor set and its copy differs */
10234                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10235                         }
10236                 }
10237                 if (in_gcc_extension) {
10238                         /* an gcc extension scope was not closed */
10239                         internal_errorf(HERE, "Leaked __extension__");
10240                 }
10241 #endif
10242
10243                 parse_external();
10244         }
10245
10246         rem_anchor_token(T_EOF);
10247         rem_anchor_token('}');
10248 }
10249
10250 /**
10251  * Parse a translation unit.
10252  */
10253 static void parse_translation_unit(void)
10254 {
10255         add_anchor_token(T_EOF);
10256
10257         while (true) {
10258                 parse_externals();
10259
10260                 if (token.kind == T_EOF)
10261                         break;
10262
10263                 errorf(HERE, "stray %K outside of function", &token);
10264                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10265                         eat_until_matching_token(token.kind);
10266                 next_token();
10267         }
10268 }
10269
10270 void set_default_visibility(elf_visibility_tag_t visibility)
10271 {
10272         default_visibility = visibility;
10273 }
10274
10275 /**
10276  * Parse the input.
10277  *
10278  * @return  the translation unit or NULL if errors occurred.
10279  */
10280 void start_parsing(void)
10281 {
10282         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10283         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10284         diagnostic_count  = 0;
10285         error_count       = 0;
10286         warning_count     = 0;
10287
10288         print_to_file(stderr);
10289
10290         assert(unit == NULL);
10291         unit = allocate_ast_zero(sizeof(unit[0]));
10292
10293         assert(file_scope == NULL);
10294         file_scope = &unit->scope;
10295
10296         assert(current_scope == NULL);
10297         scope_push(&unit->scope);
10298
10299         create_gnu_builtins();
10300         if (c_mode & _MS)
10301                 create_microsoft_intrinsics();
10302 }
10303
10304 translation_unit_t *finish_parsing(void)
10305 {
10306         assert(current_scope == &unit->scope);
10307         scope_pop(NULL);
10308
10309         assert(file_scope == &unit->scope);
10310         check_unused_globals();
10311         file_scope = NULL;
10312
10313         DEL_ARR_F(environment_stack);
10314         DEL_ARR_F(label_stack);
10315
10316         translation_unit_t *result = unit;
10317         unit = NULL;
10318         return result;
10319 }
10320
10321 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10322  * are given length one. */
10323 static void complete_incomplete_arrays(void)
10324 {
10325         size_t n = ARR_LEN(incomplete_arrays);
10326         for (size_t i = 0; i != n; ++i) {
10327                 declaration_t *const decl = incomplete_arrays[i];
10328                 type_t        *const type = skip_typeref(decl->type);
10329
10330                 if (!is_type_incomplete(type))
10331                         continue;
10332
10333                 source_position_t const *const pos = &decl->base.source_position;
10334                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10335
10336                 type_t *const new_type = duplicate_type(type);
10337                 new_type->array.size_constant     = true;
10338                 new_type->array.has_implicit_size = true;
10339                 new_type->array.size              = 1;
10340
10341                 type_t *const result = identify_new_type(new_type);
10342
10343                 decl->type = result;
10344         }
10345 }
10346
10347 static void prepare_main_collect2(entity_t *const entity)
10348 {
10349         PUSH_SCOPE(&entity->function.statement->compound.scope);
10350
10351         // create call to __main
10352         symbol_t *symbol         = symbol_table_insert("__main");
10353         entity_t *subsubmain_ent
10354                 = create_implicit_function(symbol, &builtin_source_position);
10355
10356         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10357         type_t       *ftype       = subsubmain_ent->declaration.type;
10358         ref->base.source_position = builtin_source_position;
10359         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10360         ref->reference.entity     = subsubmain_ent;
10361
10362         expression_t *call = allocate_expression_zero(EXPR_CALL);
10363         call->base.source_position = builtin_source_position;
10364         call->base.type            = type_void;
10365         call->call.function        = ref;
10366
10367         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10368         expr_statement->base.source_position  = builtin_source_position;
10369         expr_statement->expression.expression = call;
10370
10371         statement_t *statement = entity->function.statement;
10372         assert(statement->kind == STATEMENT_COMPOUND);
10373         compound_statement_t *compounds = &statement->compound;
10374
10375         expr_statement->base.next = compounds->statements;
10376         compounds->statements     = expr_statement;
10377
10378         POP_SCOPE();
10379 }
10380
10381 void parse(void)
10382 {
10383         lookahead_bufpos = 0;
10384         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10385                 next_token();
10386         }
10387         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10388         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10389         parse_translation_unit();
10390         complete_incomplete_arrays();
10391         DEL_ARR_F(incomplete_arrays);
10392         incomplete_arrays = NULL;
10393 }
10394
10395 /**
10396  * Initialize the parser.
10397  */
10398 void init_parser(void)
10399 {
10400         sym_anonymous = symbol_table_insert("<anonymous>");
10401
10402         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10403
10404         init_expression_parsers();
10405         obstack_init(&temp_obst);
10406 }
10407
10408 /**
10409  * Terminate the parser.
10410  */
10411 void exit_parser(void)
10412 {
10413         obstack_free(&temp_obst, NULL);
10414 }