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 = token.base.source_position;
 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 = token.base.source_position;
 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(&token.base.source_position);
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 = token.base.source_position;
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 = token.base.source_position;
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 = token.base.source_position;
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 = token.base.source_position;
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 = token.base.source_position;
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   = token.base.source_position;
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(&token.base.source_position);
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(&token.base.source_position,
5779                        "invalid suffix '%S' on integer constant", suffix);
5780         } else if (not_traditional) {
5781                 warn_traditional_suffix();
5782         }
5783 }
5784
5785 static type_t *check_floatingpoint_suffix(void)
5786 {
5787         const string_t *suffix = &token.number.suffix;
5788         type_t         *type   = type_double;
5789         if (suffix->size == 0)
5790                 return type;
5791
5792         bool not_traditional = false;
5793         const char *c = suffix->begin;
5794         if (*c == 'f' || *c == 'F') {
5795                 ++c;
5796                 type = type_float;
5797         } else if (*c == 'l' || *c == 'L') {
5798                 ++c;
5799                 type = type_long_double;
5800         }
5801         if (*c != '\0') {
5802                 errorf(&token.base.source_position,
5803                        "invalid suffix '%S' on floatingpoint constant", suffix);
5804         } else if (not_traditional) {
5805                 warn_traditional_suffix();
5806         }
5807
5808         return type;
5809 }
5810
5811 /**
5812  * Parse an integer constant.
5813  */
5814 static expression_t *parse_number_literal(void)
5815 {
5816         expression_kind_t  kind;
5817         type_t            *type;
5818
5819         switch (token.kind) {
5820         case T_INTEGER:
5821                 kind = EXPR_LITERAL_INTEGER;
5822                 check_integer_suffix();
5823                 type = type_int;
5824                 break;
5825
5826         case T_FLOATINGPOINT:
5827                 kind = EXPR_LITERAL_FLOATINGPOINT;
5828                 type = check_floatingpoint_suffix();
5829                 break;
5830
5831         default:
5832                 panic("unexpected token type in parse_number_literal");
5833         }
5834
5835         expression_t *literal = allocate_expression_zero(kind);
5836         literal->base.type      = type;
5837         literal->literal.value  = token.number.number;
5838         literal->literal.suffix = token.number.suffix;
5839         next_token();
5840
5841         /* integer type depends on the size of the number and the size
5842          * representable by the types. The backend/codegeneration has to determine
5843          * that
5844          */
5845         determine_literal_type(&literal->literal);
5846         return literal;
5847 }
5848
5849 /**
5850  * Parse a character constant.
5851  */
5852 static expression_t *parse_character_constant(void)
5853 {
5854         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5855         literal->base.type     = c_mode & _CXX ? type_char : type_int;
5856         literal->literal.value = token.string.string;
5857
5858         size_t len = literal->literal.value.size;
5859         if (len > 1) {
5860                 if (!GNU_MODE && !(c_mode & _C99)) {
5861                         errorf(HERE, "more than 1 character in character constant");
5862                 } else {
5863                         literal->base.type = type_int;
5864                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5865                 }
5866         }
5867
5868         next_token();
5869         return literal;
5870 }
5871
5872 /**
5873  * Parse a wide character constant.
5874  */
5875 static expression_t *parse_wide_character_constant(void)
5876 {
5877         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_WIDE_CHARACTER);
5878         literal->base.type     = type_int;
5879         literal->literal.value = token.string.string;
5880
5881         size_t len = wstrlen(&literal->literal.value);
5882         if (len > 1) {
5883                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5884         }
5885
5886         next_token();
5887         return literal;
5888 }
5889
5890 static entity_t *create_implicit_function(symbol_t *symbol, source_position_t const *const pos)
5891 {
5892         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5893         ntype->function.return_type            = type_int;
5894         ntype->function.unspecified_parameters = true;
5895         ntype->function.linkage                = LINKAGE_C;
5896         type_t *type                           = identify_new_type(ntype);
5897
5898         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5899         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5900         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5901         entity->declaration.type                   = type;
5902         entity->declaration.implicit               = true;
5903
5904         if (current_scope != NULL)
5905                 record_entity(entity, false);
5906
5907         return entity;
5908 }
5909
5910 /**
5911  * Performs automatic type cast as described in §6.3.2.1.
5912  *
5913  * @param orig_type  the original type
5914  */
5915 static type_t *automatic_type_conversion(type_t *orig_type)
5916 {
5917         type_t *type = skip_typeref(orig_type);
5918         if (is_type_array(type)) {
5919                 array_type_t *array_type   = &type->array;
5920                 type_t       *element_type = array_type->element_type;
5921                 unsigned      qualifiers   = array_type->base.qualifiers;
5922
5923                 return make_pointer_type(element_type, qualifiers);
5924         }
5925
5926         if (is_type_function(type)) {
5927                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5928         }
5929
5930         return orig_type;
5931 }
5932
5933 /**
5934  * reverts the automatic casts of array to pointer types and function
5935  * to function-pointer types as defined §6.3.2.1
5936  */
5937 type_t *revert_automatic_type_conversion(const expression_t *expression)
5938 {
5939         switch (expression->kind) {
5940         case EXPR_REFERENCE: {
5941                 entity_t *entity = expression->reference.entity;
5942                 if (is_declaration(entity)) {
5943                         return entity->declaration.type;
5944                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5945                         return entity->enum_value.enum_type;
5946                 } else {
5947                         panic("no declaration or enum in reference");
5948                 }
5949         }
5950
5951         case EXPR_SELECT: {
5952                 entity_t *entity = expression->select.compound_entry;
5953                 assert(is_declaration(entity));
5954                 type_t   *type   = entity->declaration.type;
5955                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5956         }
5957
5958         case EXPR_UNARY_DEREFERENCE: {
5959                 const expression_t *const value = expression->unary.value;
5960                 type_t             *const type  = skip_typeref(value->base.type);
5961                 if (!is_type_pointer(type))
5962                         return type_error_type;
5963                 return type->pointer.points_to;
5964         }
5965
5966         case EXPR_ARRAY_ACCESS: {
5967                 const expression_t *array_ref = expression->array_access.array_ref;
5968                 type_t             *type_left = skip_typeref(array_ref->base.type);
5969                 if (!is_type_pointer(type_left))
5970                         return type_error_type;
5971                 return type_left->pointer.points_to;
5972         }
5973
5974         case EXPR_STRING_LITERAL: {
5975                 size_t size = expression->string_literal.value.size;
5976                 return make_array_type(type_char, size, TYPE_QUALIFIER_NONE);
5977         }
5978
5979         case EXPR_WIDE_STRING_LITERAL: {
5980                 size_t size = wstrlen(&expression->string_literal.value);
5981                 return make_array_type(type_wchar_t, size, TYPE_QUALIFIER_NONE);
5982         }
5983
5984         case EXPR_COMPOUND_LITERAL:
5985                 return expression->compound_literal.type;
5986
5987         default:
5988                 break;
5989         }
5990         return expression->base.type;
5991 }
5992
5993 /**
5994  * Find an entity matching a symbol in a scope.
5995  * Uses current scope if scope is NULL
5996  */
5997 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
5998                                namespace_tag_t namespc)
5999 {
6000         if (scope == NULL) {
6001                 return get_entity(symbol, namespc);
6002         }
6003
6004         /* we should optimize here, if scope grows above a certain size we should
6005            construct a hashmap here... */
6006         entity_t *entity = scope->entities;
6007         for ( ; entity != NULL; entity = entity->base.next) {
6008                 if (entity->base.symbol == symbol
6009                     && (namespace_tag_t)entity->base.namespc == namespc)
6010                         break;
6011         }
6012
6013         return entity;
6014 }
6015
6016 static entity_t *parse_qualified_identifier(void)
6017 {
6018         /* namespace containing the symbol */
6019         symbol_t          *symbol;
6020         source_position_t  pos;
6021         const scope_t     *lookup_scope = NULL;
6022
6023         if (next_if(T_COLONCOLON))
6024                 lookup_scope = &unit->scope;
6025
6026         entity_t *entity;
6027         while (true) {
6028                 symbol = expect_identifier("while parsing identifier", &pos);
6029                 if (!symbol)
6030                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6031
6032                 /* lookup entity */
6033                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6034
6035                 if (!next_if(T_COLONCOLON))
6036                         break;
6037
6038                 switch (entity->kind) {
6039                 case ENTITY_NAMESPACE:
6040                         lookup_scope = &entity->namespacee.members;
6041                         break;
6042                 case ENTITY_STRUCT:
6043                 case ENTITY_UNION:
6044                 case ENTITY_CLASS:
6045                         lookup_scope = &entity->compound.members;
6046                         break;
6047                 default:
6048                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6049                                symbol, get_entity_kind_name(entity->kind));
6050
6051                         /* skip further qualifications */
6052                         while (next_if(T_IDENTIFIER) && next_if(T_COLONCOLON)) {}
6053
6054                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6055                 }
6056         }
6057
6058         if (entity == NULL) {
6059                 if (!strict_mode && token.kind == '(') {
6060                         /* an implicitly declared function */
6061                         entity = create_implicit_function(symbol, &pos);
6062                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6063                 } else {
6064                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6065                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6066                 }
6067         }
6068
6069         return entity;
6070 }
6071
6072 static expression_t *parse_reference(void)
6073 {
6074         source_position_t const pos    = token.base.source_position;
6075         entity_t         *const entity = parse_qualified_identifier();
6076
6077         type_t *orig_type;
6078         if (is_declaration(entity)) {
6079                 orig_type = entity->declaration.type;
6080         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6081                 orig_type = entity->enum_value.enum_type;
6082         } else {
6083                 panic("expected declaration or enum value in reference");
6084         }
6085
6086         /* we always do the auto-type conversions; the & and sizeof parser contains
6087          * code to revert this! */
6088         type_t *type = automatic_type_conversion(orig_type);
6089
6090         expression_kind_t kind = EXPR_REFERENCE;
6091         if (entity->kind == ENTITY_ENUM_VALUE)
6092                 kind = EXPR_ENUM_CONSTANT;
6093
6094         expression_t *expression         = allocate_expression_zero(kind);
6095         expression->base.source_position = pos;
6096         expression->base.type            = type;
6097         expression->reference.entity     = entity;
6098
6099         /* this declaration is used */
6100         if (is_declaration(entity)) {
6101                 entity->declaration.used = true;
6102         }
6103
6104         if (entity->base.parent_scope != file_scope
6105                 && (current_function != NULL
6106                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6107                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6108                 /* access of a variable from an outer function */
6109                 entity->variable.address_taken = true;
6110                 current_function->need_closure = true;
6111         }
6112
6113         check_deprecated(&pos, entity);
6114
6115         return expression;
6116 }
6117
6118 static bool semantic_cast(expression_t *cast)
6119 {
6120         expression_t            *expression      = cast->unary.value;
6121         type_t                  *orig_dest_type  = cast->base.type;
6122         type_t                  *orig_type_right = expression->base.type;
6123         type_t            const *dst_type        = skip_typeref(orig_dest_type);
6124         type_t            const *src_type        = skip_typeref(orig_type_right);
6125         source_position_t const *pos             = &cast->base.source_position;
6126
6127         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6128         if (is_type_void(dst_type))
6129                 return true;
6130
6131         /* only integer and pointer can be casted to pointer */
6132         if (is_type_pointer(dst_type)  &&
6133             !is_type_pointer(src_type) &&
6134             !is_type_integer(src_type) &&
6135             is_type_valid(src_type)) {
6136                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6137                 return false;
6138         }
6139
6140         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6141                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6142                 return false;
6143         }
6144
6145         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6146                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6147                 return false;
6148         }
6149
6150         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6151                 type_t *src = skip_typeref(src_type->pointer.points_to);
6152                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6153                 unsigned missing_qualifiers =
6154                         src->base.qualifiers & ~dst->base.qualifiers;
6155                 if (missing_qualifiers != 0) {
6156                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6157                 }
6158         }
6159         return true;
6160 }
6161
6162 static expression_t *parse_compound_literal(source_position_t const *const pos, type_t *type)
6163 {
6164         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6165         expression->base.source_position = *pos;
6166
6167         parse_initializer_env_t env;
6168         env.type             = type;
6169         env.entity           = NULL;
6170         env.must_be_constant = false;
6171         initializer_t *initializer = parse_initializer(&env);
6172         type = env.type;
6173
6174         expression->compound_literal.initializer = initializer;
6175         expression->compound_literal.type        = type;
6176         expression->base.type                    = automatic_type_conversion(type);
6177
6178         return expression;
6179 }
6180
6181 /**
6182  * Parse a cast expression.
6183  */
6184 static expression_t *parse_cast(void)
6185 {
6186         source_position_t const pos = *HERE;
6187
6188         eat('(');
6189         add_anchor_token(')');
6190
6191         type_t *type = parse_typename();
6192
6193         rem_anchor_token(')');
6194         expect(')');
6195
6196         if (token.kind == '{') {
6197                 return parse_compound_literal(&pos, type);
6198         }
6199
6200         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6201         cast->base.source_position = pos;
6202
6203         expression_t *value = parse_subexpression(PREC_CAST);
6204         cast->base.type   = type;
6205         cast->unary.value = value;
6206
6207         if (! semantic_cast(cast)) {
6208                 /* TODO: record the error in the AST. else it is impossible to detect it */
6209         }
6210
6211         return cast;
6212 }
6213
6214 /**
6215  * Parse a statement expression.
6216  */
6217 static expression_t *parse_statement_expression(void)
6218 {
6219         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6220
6221         eat('(');
6222         add_anchor_token(')');
6223
6224         statement_t *statement          = parse_compound_statement(true);
6225         statement->compound.stmt_expr   = true;
6226         expression->statement.statement = statement;
6227
6228         /* find last statement and use its type */
6229         type_t *type = type_void;
6230         const statement_t *stmt = statement->compound.statements;
6231         if (stmt != NULL) {
6232                 while (stmt->base.next != NULL)
6233                         stmt = stmt->base.next;
6234
6235                 if (stmt->kind == STATEMENT_EXPRESSION) {
6236                         type = stmt->expression.expression->base.type;
6237                 }
6238         } else {
6239                 source_position_t const *const pos = &expression->base.source_position;
6240                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6241         }
6242         expression->base.type = type;
6243
6244         rem_anchor_token(')');
6245         expect(')');
6246         return expression;
6247 }
6248
6249 /**
6250  * Parse a parenthesized expression.
6251  */
6252 static expression_t *parse_parenthesized_expression(void)
6253 {
6254         token_t const* const la1 = look_ahead(1);
6255         switch (la1->kind) {
6256         case '{':
6257                 /* gcc extension: a statement expression */
6258                 return parse_statement_expression();
6259
6260         case T_IDENTIFIER:
6261                 if (is_typedef_symbol(la1->base.symbol)) {
6262         DECLARATION_START
6263                         return parse_cast();
6264                 }
6265         }
6266
6267         eat('(');
6268         add_anchor_token(')');
6269         expression_t *result = parse_expression();
6270         result->base.parenthesized = true;
6271         rem_anchor_token(')');
6272         expect(')');
6273
6274         return result;
6275 }
6276
6277 static expression_t *parse_function_keyword(void)
6278 {
6279         /* TODO */
6280
6281         if (current_function == NULL) {
6282                 errorf(HERE, "'__func__' used outside of a function");
6283         }
6284
6285         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6286         expression->base.type     = type_char_ptr;
6287         expression->funcname.kind = FUNCNAME_FUNCTION;
6288
6289         next_token();
6290
6291         return expression;
6292 }
6293
6294 static expression_t *parse_pretty_function_keyword(void)
6295 {
6296         if (current_function == NULL) {
6297                 errorf(HERE, "'__PRETTY_FUNCTION__' used outside of a function");
6298         }
6299
6300         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6301         expression->base.type     = type_char_ptr;
6302         expression->funcname.kind = FUNCNAME_PRETTY_FUNCTION;
6303
6304         eat(T___PRETTY_FUNCTION__);
6305
6306         return expression;
6307 }
6308
6309 static expression_t *parse_funcsig_keyword(void)
6310 {
6311         if (current_function == NULL) {
6312                 errorf(HERE, "'__FUNCSIG__' used outside of a function");
6313         }
6314
6315         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6316         expression->base.type     = type_char_ptr;
6317         expression->funcname.kind = FUNCNAME_FUNCSIG;
6318
6319         eat(T___FUNCSIG__);
6320
6321         return expression;
6322 }
6323
6324 static expression_t *parse_funcdname_keyword(void)
6325 {
6326         if (current_function == NULL) {
6327                 errorf(HERE, "'__FUNCDNAME__' used outside of a function");
6328         }
6329
6330         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6331         expression->base.type     = type_char_ptr;
6332         expression->funcname.kind = FUNCNAME_FUNCDNAME;
6333
6334         eat(T___FUNCDNAME__);
6335
6336         return expression;
6337 }
6338
6339 static designator_t *parse_designator(void)
6340 {
6341         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6342         result->symbol = expect_identifier("while parsing member designator", &result->source_position);
6343         if (!result->symbol)
6344                 return NULL;
6345
6346         designator_t *last_designator = result;
6347         while (true) {
6348                 if (next_if('.')) {
6349                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6350                         designator->symbol = expect_identifier("while parsing member designator", &designator->source_position);
6351                         if (!designator->symbol)
6352                                 return NULL;
6353
6354                         last_designator->next = designator;
6355                         last_designator       = designator;
6356                         continue;
6357                 }
6358                 if (next_if('[')) {
6359                         add_anchor_token(']');
6360                         designator_t *designator    = allocate_ast_zero(sizeof(result[0]));
6361                         designator->source_position = *HERE;
6362                         designator->array_index     = parse_expression();
6363                         rem_anchor_token(']');
6364                         expect(']');
6365                         if (designator->array_index == NULL) {
6366                                 return NULL;
6367                         }
6368
6369                         last_designator->next = designator;
6370                         last_designator       = designator;
6371                         continue;
6372                 }
6373                 break;
6374         }
6375
6376         return result;
6377 }
6378
6379 /**
6380  * Parse the __builtin_offsetof() expression.
6381  */
6382 static expression_t *parse_offsetof(void)
6383 {
6384         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6385         expression->base.type    = type_size_t;
6386
6387         eat(T___builtin_offsetof);
6388
6389         expect('(');
6390         add_anchor_token(')');
6391         add_anchor_token(',');
6392         type_t *type = parse_typename();
6393         rem_anchor_token(',');
6394         expect(',');
6395         designator_t *designator = parse_designator();
6396         rem_anchor_token(')');
6397         expect(')');
6398
6399         expression->offsetofe.type       = type;
6400         expression->offsetofe.designator = designator;
6401
6402         type_path_t path;
6403         memset(&path, 0, sizeof(path));
6404         path.top_type = type;
6405         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6406
6407         descend_into_subtype(&path);
6408
6409         if (!walk_designator(&path, designator, true)) {
6410                 return create_error_expression();
6411         }
6412
6413         DEL_ARR_F(path.path);
6414
6415         return expression;
6416 }
6417
6418 /**
6419  * Parses a _builtin_va_start() expression.
6420  */
6421 static expression_t *parse_va_start(void)
6422 {
6423         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6424
6425         eat(T___builtin_va_start);
6426
6427         expect('(');
6428         add_anchor_token(')');
6429         add_anchor_token(',');
6430         expression->va_starte.ap = parse_assignment_expression();
6431         rem_anchor_token(',');
6432         expect(',');
6433         expression_t *const param = parse_assignment_expression();
6434         expression->va_starte.parameter = param;
6435         rem_anchor_token(')');
6436         expect(')');
6437
6438         if (!current_function) {
6439                 errorf(&expression->base.source_position, "'va_start' used outside of function");
6440         } else if (!current_function->base.type->function.variadic) {
6441                 errorf(&expression->base.source_position, "'va_start' used in non-variadic function");
6442         } else if (param->kind == EXPR_REFERENCE) {
6443                 entity_t *const entity = param->reference.entity;
6444                 if (entity->base.parent_scope != &current_function->parameters ||
6445                                 entity->base.next != NULL ||
6446                                 entity->kind != ENTITY_PARAMETER) {
6447                         errorf(&param->base.source_position,
6448                                "second argument of 'va_start' must be last parameter of the current function");
6449                 }
6450         } else {
6451                 expression = create_error_expression();
6452         }
6453
6454         return expression;
6455 }
6456
6457 /**
6458  * Parses a __builtin_va_arg() expression.
6459  */
6460 static expression_t *parse_va_arg(void)
6461 {
6462         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6463
6464         eat(T___builtin_va_arg);
6465
6466         expect('(');
6467         add_anchor_token(')');
6468         add_anchor_token(',');
6469         call_argument_t ap;
6470         ap.expression = parse_assignment_expression();
6471         expression->va_arge.ap = ap.expression;
6472         check_call_argument(type_valist, &ap, 1);
6473
6474         rem_anchor_token(',');
6475         expect(',');
6476         expression->base.type = parse_typename();
6477         rem_anchor_token(')');
6478         expect(')');
6479
6480         return expression;
6481 }
6482
6483 /**
6484  * Parses a __builtin_va_copy() expression.
6485  */
6486 static expression_t *parse_va_copy(void)
6487 {
6488         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6489
6490         eat(T___builtin_va_copy);
6491
6492         expect('(');
6493         add_anchor_token(')');
6494         add_anchor_token(',');
6495         expression_t *dst = parse_assignment_expression();
6496         assign_error_t error = semantic_assign(type_valist, dst);
6497         report_assign_error(error, type_valist, dst, "call argument 1",
6498                             &dst->base.source_position);
6499         expression->va_copye.dst = dst;
6500
6501         rem_anchor_token(',');
6502         expect(',');
6503
6504         call_argument_t src;
6505         src.expression = parse_assignment_expression();
6506         check_call_argument(type_valist, &src, 2);
6507         expression->va_copye.src = src.expression;
6508         rem_anchor_token(')');
6509         expect(')');
6510
6511         return expression;
6512 }
6513
6514 /**
6515  * Parses a __builtin_constant_p() expression.
6516  */
6517 static expression_t *parse_builtin_constant(void)
6518 {
6519         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6520
6521         eat(T___builtin_constant_p);
6522
6523         expect('(');
6524         add_anchor_token(')');
6525         expression->builtin_constant.value = parse_assignment_expression();
6526         rem_anchor_token(')');
6527         expect(')');
6528         expression->base.type = type_int;
6529
6530         return expression;
6531 }
6532
6533 /**
6534  * Parses a __builtin_types_compatible_p() expression.
6535  */
6536 static expression_t *parse_builtin_types_compatible(void)
6537 {
6538         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6539
6540         eat(T___builtin_types_compatible_p);
6541
6542         expect('(');
6543         add_anchor_token(')');
6544         add_anchor_token(',');
6545         expression->builtin_types_compatible.left = parse_typename();
6546         rem_anchor_token(',');
6547         expect(',');
6548         expression->builtin_types_compatible.right = parse_typename();
6549         rem_anchor_token(')');
6550         expect(')');
6551         expression->base.type = type_int;
6552
6553         return expression;
6554 }
6555
6556 /**
6557  * Parses a __builtin_is_*() compare expression.
6558  */
6559 static expression_t *parse_compare_builtin(void)
6560 {
6561         expression_t *expression;
6562
6563         switch (token.kind) {
6564         case T___builtin_isgreater:
6565                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATER);
6566                 break;
6567         case T___builtin_isgreaterequal:
6568                 expression = allocate_expression_zero(EXPR_BINARY_ISGREATEREQUAL);
6569                 break;
6570         case T___builtin_isless:
6571                 expression = allocate_expression_zero(EXPR_BINARY_ISLESS);
6572                 break;
6573         case T___builtin_islessequal:
6574                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSEQUAL);
6575                 break;
6576         case T___builtin_islessgreater:
6577                 expression = allocate_expression_zero(EXPR_BINARY_ISLESSGREATER);
6578                 break;
6579         case T___builtin_isunordered:
6580                 expression = allocate_expression_zero(EXPR_BINARY_ISUNORDERED);
6581                 break;
6582         default:
6583                 internal_errorf(HERE, "invalid compare builtin found");
6584         }
6585         expression->base.source_position = *HERE;
6586         next_token();
6587
6588         expect('(');
6589         add_anchor_token(')');
6590         add_anchor_token(',');
6591         expression->binary.left = parse_assignment_expression();
6592         rem_anchor_token(',');
6593         expect(',');
6594         expression->binary.right = parse_assignment_expression();
6595         rem_anchor_token(')');
6596         expect(')');
6597
6598         type_t *const orig_type_left  = expression->binary.left->base.type;
6599         type_t *const orig_type_right = expression->binary.right->base.type;
6600
6601         type_t *const type_left  = skip_typeref(orig_type_left);
6602         type_t *const type_right = skip_typeref(orig_type_right);
6603         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6604                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6605                         type_error_incompatible("invalid operands in comparison",
6606                                 &expression->base.source_position, orig_type_left, orig_type_right);
6607                 }
6608         } else {
6609                 semantic_comparison(&expression->binary);
6610         }
6611
6612         return expression;
6613 }
6614
6615 /**
6616  * Parses a MS assume() expression.
6617  */
6618 static expression_t *parse_assume(void)
6619 {
6620         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6621
6622         eat(T__assume);
6623
6624         expect('(');
6625         add_anchor_token(')');
6626         expression->unary.value = parse_assignment_expression();
6627         rem_anchor_token(')');
6628         expect(')');
6629
6630         expression->base.type = type_void;
6631         return expression;
6632 }
6633
6634 /**
6635  * Return the label for the current symbol or create a new one.
6636  */
6637 static label_t *get_label(void)
6638 {
6639         assert(token.kind == T_IDENTIFIER);
6640         assert(current_function != NULL);
6641
6642         entity_t *label = get_entity(token.base.symbol, NAMESPACE_LABEL);
6643         /* If we find a local label, we already created the declaration. */
6644         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6645                 if (label->base.parent_scope != current_scope) {
6646                         assert(label->base.parent_scope->depth < current_scope->depth);
6647                         current_function->goto_to_outer = true;
6648                 }
6649         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6650                 /* There is no matching label in the same function, so create a new one. */
6651                 source_position_t const nowhere = { NULL, 0, 0, false };
6652                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, token.base.symbol, &nowhere);
6653                 label_push(label);
6654         }
6655
6656         eat(T_IDENTIFIER);
6657         return &label->label;
6658 }
6659
6660 /**
6661  * Parses a GNU && label address expression.
6662  */
6663 static expression_t *parse_label_address(void)
6664 {
6665         source_position_t source_position = token.base.source_position;
6666         eat(T_ANDAND);
6667         if (token.kind != T_IDENTIFIER) {
6668                 parse_error_expected("while parsing label address", T_IDENTIFIER, NULL);
6669                 return create_error_expression();
6670         }
6671
6672         label_t *const label = get_label();
6673         label->used          = true;
6674         label->address_taken = true;
6675
6676         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6677         expression->base.source_position = source_position;
6678
6679         /* label address is treated as a void pointer */
6680         expression->base.type           = type_void_ptr;
6681         expression->label_address.label = label;
6682         return expression;
6683 }
6684
6685 /**
6686  * Parse a microsoft __noop expression.
6687  */
6688 static expression_t *parse_noop_expression(void)
6689 {
6690         /* the result is a (int)0 */
6691         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6692         literal->base.type           = type_int;
6693         literal->literal.value.begin = "__noop";
6694         literal->literal.value.size  = 6;
6695
6696         eat(T___noop);
6697
6698         if (token.kind == '(') {
6699                 /* parse arguments */
6700                 eat('(');
6701                 add_anchor_token(')');
6702                 add_anchor_token(',');
6703
6704                 if (token.kind != ')') do {
6705                         (void)parse_assignment_expression();
6706                 } while (next_if(','));
6707
6708                 rem_anchor_token(',');
6709                 rem_anchor_token(')');
6710         }
6711         expect(')');
6712
6713         return literal;
6714 }
6715
6716 /**
6717  * Parses a primary expression.
6718  */
6719 static expression_t *parse_primary_expression(void)
6720 {
6721         switch (token.kind) {
6722         case T_false:                        return parse_boolean_literal(false);
6723         case T_true:                         return parse_boolean_literal(true);
6724         case T_INTEGER:
6725         case T_FLOATINGPOINT:                return parse_number_literal();
6726         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6727         case T_WIDE_CHARACTER_CONSTANT:      return parse_wide_character_constant();
6728         case T_STRING_LITERAL:
6729         case T_WIDE_STRING_LITERAL:          return parse_string_literal();
6730         case T___FUNCTION__:
6731         case T___func__:                     return parse_function_keyword();
6732         case T___PRETTY_FUNCTION__:          return parse_pretty_function_keyword();
6733         case T___FUNCSIG__:                  return parse_funcsig_keyword();
6734         case T___FUNCDNAME__:                return parse_funcdname_keyword();
6735         case T___builtin_offsetof:           return parse_offsetof();
6736         case T___builtin_va_start:           return parse_va_start();
6737         case T___builtin_va_arg:             return parse_va_arg();
6738         case T___builtin_va_copy:            return parse_va_copy();
6739         case T___builtin_isgreater:
6740         case T___builtin_isgreaterequal:
6741         case T___builtin_isless:
6742         case T___builtin_islessequal:
6743         case T___builtin_islessgreater:
6744         case T___builtin_isunordered:        return parse_compare_builtin();
6745         case T___builtin_constant_p:         return parse_builtin_constant();
6746         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6747         case T__assume:                      return parse_assume();
6748         case T_ANDAND:
6749                 if (GNU_MODE)
6750                         return parse_label_address();
6751                 break;
6752
6753         case '(':                            return parse_parenthesized_expression();
6754         case T___noop:                       return parse_noop_expression();
6755
6756         /* Gracefully handle type names while parsing expressions. */
6757         case T_COLONCOLON:
6758                 return parse_reference();
6759         case T_IDENTIFIER:
6760                 if (!is_typedef_symbol(token.base.symbol)) {
6761                         return parse_reference();
6762                 }
6763                 /* FALLTHROUGH */
6764         DECLARATION_START {
6765                 source_position_t const  pos = *HERE;
6766                 declaration_specifiers_t specifiers;
6767                 parse_declaration_specifiers(&specifiers);
6768                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6769                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6770                 return create_error_expression();
6771         }
6772         }
6773
6774         errorf(HERE, "unexpected token %K, expected an expression", &token);
6775         eat_until_anchor();
6776         return create_error_expression();
6777 }
6778
6779 static expression_t *parse_array_expression(expression_t *left)
6780 {
6781         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6782         array_access_expression_t *const arr  = &expr->array_access;
6783
6784         eat('[');
6785         add_anchor_token(']');
6786
6787         expression_t *const inside = parse_expression();
6788
6789         type_t *const orig_type_left   = left->base.type;
6790         type_t *const orig_type_inside = inside->base.type;
6791
6792         type_t *const type_left   = skip_typeref(orig_type_left);
6793         type_t *const type_inside = skip_typeref(orig_type_inside);
6794
6795         expression_t *ref;
6796         expression_t *idx;
6797         type_t       *idx_type;
6798         type_t       *res_type;
6799         if (is_type_pointer(type_left)) {
6800                 ref      = left;
6801                 idx      = inside;
6802                 idx_type = type_inside;
6803                 res_type = type_left->pointer.points_to;
6804                 goto check_idx;
6805         } else if (is_type_pointer(type_inside)) {
6806                 arr->flipped = true;
6807                 ref      = inside;
6808                 idx      = left;
6809                 idx_type = type_left;
6810                 res_type = type_inside->pointer.points_to;
6811 check_idx:
6812                 res_type = automatic_type_conversion(res_type);
6813                 if (!is_type_integer(idx_type)) {
6814                         errorf(&idx->base.source_position, "array subscript must have integer type");
6815                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6816                         source_position_t const *const pos = &idx->base.source_position;
6817                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6818                 }
6819         } else {
6820                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6821                         errorf(&expr->base.source_position, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6822                 }
6823                 res_type = type_error_type;
6824                 ref      = left;
6825                 idx      = inside;
6826         }
6827
6828         arr->array_ref = ref;
6829         arr->index     = idx;
6830         arr->base.type = res_type;
6831
6832         rem_anchor_token(']');
6833         expect(']');
6834         return expr;
6835 }
6836
6837 static bool is_bitfield(const expression_t *expression)
6838 {
6839         return expression->kind == EXPR_SELECT
6840                 && expression->select.compound_entry->compound_member.bitfield;
6841 }
6842
6843 static expression_t *parse_typeprop(expression_kind_t const kind)
6844 {
6845         expression_t  *tp_expression = allocate_expression_zero(kind);
6846         tp_expression->base.type     = type_size_t;
6847
6848         eat(kind == EXPR_SIZEOF ? T_sizeof : T___alignof__);
6849
6850         type_t       *orig_type;
6851         expression_t *expression;
6852         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6853                 source_position_t const pos = *HERE;
6854                 next_token();
6855                 add_anchor_token(')');
6856                 orig_type = parse_typename();
6857                 rem_anchor_token(')');
6858                 expect(')');
6859
6860                 if (token.kind == '{') {
6861                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6862                          * starting with a compound literal */
6863                         expression = parse_compound_literal(&pos, orig_type);
6864                         goto typeprop_expression;
6865                 }
6866         } else {
6867                 expression = parse_subexpression(PREC_UNARY);
6868
6869 typeprop_expression:
6870                 if (is_bitfield(expression)) {
6871                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6872                         errorf(&tp_expression->base.source_position,
6873                                    "operand of %s expression must not be a bitfield", what);
6874                 }
6875
6876                 tp_expression->typeprop.tp_expression = expression;
6877
6878                 orig_type = revert_automatic_type_conversion(expression);
6879                 expression->base.type = orig_type;
6880         }
6881
6882         tp_expression->typeprop.type   = orig_type;
6883         type_t const* const type       = skip_typeref(orig_type);
6884         char   const*       wrong_type = NULL;
6885         if (is_type_incomplete(type)) {
6886                 if (!is_type_void(type) || !GNU_MODE)
6887                         wrong_type = "incomplete";
6888         } else if (type->kind == TYPE_FUNCTION) {
6889                 if (GNU_MODE) {
6890                         /* function types are allowed (and return 1) */
6891                         source_position_t const *const pos  = &tp_expression->base.source_position;
6892                         char              const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6893                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6894                 } else {
6895                         wrong_type = "function";
6896                 }
6897         }
6898
6899         if (wrong_type != NULL) {
6900                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6901                 errorf(&tp_expression->base.source_position,
6902                                 "operand of %s expression must not be of %s type '%T'",
6903                                 what, wrong_type, orig_type);
6904         }
6905
6906         return tp_expression;
6907 }
6908
6909 static expression_t *parse_sizeof(void)
6910 {
6911         return parse_typeprop(EXPR_SIZEOF);
6912 }
6913
6914 static expression_t *parse_alignof(void)
6915 {
6916         return parse_typeprop(EXPR_ALIGNOF);
6917 }
6918
6919 static expression_t *parse_select_expression(expression_t *addr)
6920 {
6921         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6922         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6923         source_position_t const pos = *HERE;
6924         next_token();
6925
6926         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6927         if (!symbol)
6928                 return create_error_expression();
6929
6930         type_t *const orig_type = addr->base.type;
6931         type_t *const type      = skip_typeref(orig_type);
6932
6933         type_t *type_left;
6934         bool    saw_error = false;
6935         if (is_type_pointer(type)) {
6936                 if (!select_left_arrow) {
6937                         errorf(&pos,
6938                                "request for member '%Y' in something not a struct or union, but '%T'",
6939                                symbol, orig_type);
6940                         saw_error = true;
6941                 }
6942                 type_left = skip_typeref(type->pointer.points_to);
6943         } else {
6944                 if (select_left_arrow && is_type_valid(type)) {
6945                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6946                         saw_error = true;
6947                 }
6948                 type_left = type;
6949         }
6950
6951         if (type_left->kind != TYPE_COMPOUND_STRUCT &&
6952             type_left->kind != TYPE_COMPOUND_UNION) {
6953
6954                 if (is_type_valid(type_left) && !saw_error) {
6955                         errorf(&pos,
6956                                "request for member '%Y' in something not a struct or union, but '%T'",
6957                                symbol, type_left);
6958                 }
6959                 return create_error_expression();
6960         }
6961
6962         compound_t *compound = type_left->compound.compound;
6963         if (!compound->complete) {
6964                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6965                        symbol, type_left);
6966                 return create_error_expression();
6967         }
6968
6969         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6970         expression_t      *result     =
6971                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6972
6973         if (result == NULL) {
6974                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6975                 return create_error_expression();
6976         }
6977
6978         return result;
6979 }
6980
6981 static void check_call_argument(type_t          *expected_type,
6982                                 call_argument_t *argument, unsigned pos)
6983 {
6984         type_t         *expected_type_skip = skip_typeref(expected_type);
6985         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6986         expression_t   *arg_expr           = argument->expression;
6987         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6988
6989         /* handle transparent union gnu extension */
6990         if (is_type_union(expected_type_skip)
6991                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6992                 compound_t *union_decl  = expected_type_skip->compound.compound;
6993                 type_t     *best_type   = NULL;
6994                 entity_t   *entry       = union_decl->members.entities;
6995                 for ( ; entry != NULL; entry = entry->base.next) {
6996                         assert(is_declaration(entry));
6997                         type_t *decl_type = entry->declaration.type;
6998                         error = semantic_assign(decl_type, arg_expr);
6999                         if (error == ASSIGN_ERROR_INCOMPATIBLE
7000                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
7001                                 continue;
7002
7003                         if (error == ASSIGN_SUCCESS) {
7004                                 best_type = decl_type;
7005                         } else if (best_type == NULL) {
7006                                 best_type = decl_type;
7007                         }
7008                 }
7009
7010                 if (best_type != NULL) {
7011                         expected_type = best_type;
7012                 }
7013         }
7014
7015         error                = semantic_assign(expected_type, arg_expr);
7016         argument->expression = create_implicit_cast(arg_expr, expected_type);
7017
7018         if (error != ASSIGN_SUCCESS) {
7019                 /* report exact scope in error messages (like "in argument 3") */
7020                 char buf[64];
7021                 snprintf(buf, sizeof(buf), "call argument %u", pos);
7022                 report_assign_error(error, expected_type, arg_expr, buf,
7023                                     &arg_expr->base.source_position);
7024         } else {
7025                 type_t *const promoted_type = get_default_promoted_type(arg_type);
7026                 if (!types_compatible(expected_type_skip, promoted_type) &&
7027                     !types_compatible(expected_type_skip, type_void_ptr) &&
7028                     !types_compatible(type_void_ptr,      promoted_type)) {
7029                         /* Deliberately show the skipped types in this warning */
7030                         source_position_t const *const apos = &arg_expr->base.source_position;
7031                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7032                 }
7033         }
7034 }
7035
7036 /**
7037  * Handle the semantic restrictions of builtin calls
7038  */
7039 static void handle_builtin_argument_restrictions(call_expression_t *call)
7040 {
7041         entity_t *entity = call->function->reference.entity;
7042         switch (entity->function.btk) {
7043         case BUILTIN_FIRM:
7044                 switch (entity->function.b.firm_builtin_kind) {
7045                 case ir_bk_return_address:
7046                 case ir_bk_frame_address: {
7047                         /* argument must be constant */
7048                         call_argument_t *argument = call->arguments;
7049
7050                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7051                                 errorf(&call->base.source_position,
7052                                            "argument of '%Y' must be a constant expression",
7053                                            call->function->reference.entity->base.symbol);
7054                         }
7055                         break;
7056                 }
7057                 case ir_bk_prefetch:
7058                         /* second and third argument must be constant if existent */
7059                         if (call->arguments == NULL)
7060                                 break;
7061                         call_argument_t *rw = call->arguments->next;
7062                         call_argument_t *locality = NULL;
7063
7064                         if (rw != NULL) {
7065                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7066                                         errorf(&call->base.source_position,
7067                                                    "second argument of '%Y' must be a constant expression",
7068                                                    call->function->reference.entity->base.symbol);
7069                                 }
7070                                 locality = rw->next;
7071                         }
7072                         if (locality != NULL) {
7073                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7074                                         errorf(&call->base.source_position,
7075                                                    "third argument of '%Y' must be a constant expression",
7076                                                    call->function->reference.entity->base.symbol);
7077                                 }
7078                                 locality = rw->next;
7079                         }
7080                         break;
7081                 default:
7082                         break;
7083                 }
7084
7085         case BUILTIN_OBJECT_SIZE:
7086                 if (call->arguments == NULL)
7087                         break;
7088
7089                 call_argument_t *arg = call->arguments->next;
7090                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7091                         errorf(&call->base.source_position,
7092                                    "second argument of '%Y' must be a constant expression",
7093                                    call->function->reference.entity->base.symbol);
7094                 }
7095                 break;
7096         default:
7097                 break;
7098         }
7099 }
7100
7101 /**
7102  * Parse a call expression, ie. expression '( ... )'.
7103  *
7104  * @param expression  the function address
7105  */
7106 static expression_t *parse_call_expression(expression_t *expression)
7107 {
7108         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7109         call_expression_t *call   = &result->call;
7110         call->function            = expression;
7111
7112         type_t *const orig_type = expression->base.type;
7113         type_t *const type      = skip_typeref(orig_type);
7114
7115         function_type_t *function_type = NULL;
7116         if (is_type_pointer(type)) {
7117                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7118
7119                 if (is_type_function(to_type)) {
7120                         function_type   = &to_type->function;
7121                         call->base.type = function_type->return_type;
7122                 }
7123         }
7124
7125         if (function_type == NULL && is_type_valid(type)) {
7126                 errorf(HERE,
7127                        "called object '%E' (type '%T') is not a pointer to a function",
7128                        expression, orig_type);
7129         }
7130
7131         /* parse arguments */
7132         eat('(');
7133         add_anchor_token(')');
7134         add_anchor_token(',');
7135
7136         if (token.kind != ')') {
7137                 call_argument_t **anchor = &call->arguments;
7138                 do {
7139                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7140                         argument->expression = parse_assignment_expression();
7141
7142                         *anchor = argument;
7143                         anchor  = &argument->next;
7144                 } while (next_if(','));
7145         }
7146         rem_anchor_token(',');
7147         rem_anchor_token(')');
7148         expect(')');
7149
7150         if (function_type == NULL)
7151                 return result;
7152
7153         /* check type and count of call arguments */
7154         function_parameter_t *parameter = function_type->parameters;
7155         call_argument_t      *argument  = call->arguments;
7156         if (!function_type->unspecified_parameters) {
7157                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7158                                 parameter = parameter->next, argument = argument->next) {
7159                         check_call_argument(parameter->type, argument, ++pos);
7160                 }
7161
7162                 if (parameter != NULL) {
7163                         errorf(&expression->base.source_position, "too few arguments to function '%E'", expression);
7164                 } else if (argument != NULL && !function_type->variadic) {
7165                         errorf(&argument->expression->base.source_position, "too many arguments to function '%E'", expression);
7166                 }
7167         }
7168
7169         /* do default promotion for other arguments */
7170         for (; argument != NULL; argument = argument->next) {
7171                 type_t *argument_type = argument->expression->base.type;
7172                 if (!is_type_object(skip_typeref(argument_type))) {
7173                         errorf(&argument->expression->base.source_position,
7174                                "call argument '%E' must not be void", argument->expression);
7175                 }
7176
7177                 argument_type = get_default_promoted_type(argument_type);
7178
7179                 argument->expression
7180                         = create_implicit_cast(argument->expression, argument_type);
7181         }
7182
7183         check_format(call);
7184
7185         if (is_type_compound(skip_typeref(function_type->return_type))) {
7186                 source_position_t const *const pos = &expression->base.source_position;
7187                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7188         }
7189
7190         if (expression->kind == EXPR_REFERENCE) {
7191                 reference_expression_t *reference = &expression->reference;
7192                 if (reference->entity->kind == ENTITY_FUNCTION &&
7193                     reference->entity->function.btk != BUILTIN_NONE)
7194                         handle_builtin_argument_restrictions(call);
7195         }
7196
7197         return result;
7198 }
7199
7200 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7201
7202 static bool same_compound_type(const type_t *type1, const type_t *type2)
7203 {
7204         return
7205                 is_type_compound(type1) &&
7206                 type1->kind == type2->kind &&
7207                 type1->compound.compound == type2->compound.compound;
7208 }
7209
7210 static expression_t const *get_reference_address(expression_t const *expr)
7211 {
7212         bool regular_take_address = true;
7213         for (;;) {
7214                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7215                         expr = expr->unary.value;
7216                 } else {
7217                         regular_take_address = false;
7218                 }
7219
7220                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7221                         break;
7222
7223                 expr = expr->unary.value;
7224         }
7225
7226         if (expr->kind != EXPR_REFERENCE)
7227                 return NULL;
7228
7229         /* special case for functions which are automatically converted to a
7230          * pointer to function without an extra TAKE_ADDRESS operation */
7231         if (!regular_take_address &&
7232                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7233                 return NULL;
7234         }
7235
7236         return expr;
7237 }
7238
7239 static void warn_reference_address_as_bool(expression_t const* expr)
7240 {
7241         expr = get_reference_address(expr);
7242         if (expr != NULL) {
7243                 source_position_t const *const pos = &expr->base.source_position;
7244                 entity_t          const *const ent = expr->reference.entity;
7245                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7246         }
7247 }
7248
7249 static void warn_assignment_in_condition(const expression_t *const expr)
7250 {
7251         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7252                 return;
7253         if (expr->base.parenthesized)
7254                 return;
7255         source_position_t const *const pos = &expr->base.source_position;
7256         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7257 }
7258
7259 static void semantic_condition(expression_t const *const expr,
7260                                char const *const context)
7261 {
7262         type_t *const type = skip_typeref(expr->base.type);
7263         if (is_type_scalar(type)) {
7264                 warn_reference_address_as_bool(expr);
7265                 warn_assignment_in_condition(expr);
7266         } else if (is_type_valid(type)) {
7267                 errorf(&expr->base.source_position,
7268                                 "%s must have scalar type", context);
7269         }
7270 }
7271
7272 /**
7273  * Parse a conditional expression, ie. 'expression ? ... : ...'.
7274  *
7275  * @param expression  the conditional expression
7276  */
7277 static expression_t *parse_conditional_expression(expression_t *expression)
7278 {
7279         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7280
7281         conditional_expression_t *conditional = &result->conditional;
7282         conditional->condition                = expression;
7283
7284         eat('?');
7285         add_anchor_token(':');
7286
7287         /* §6.5.15:2  The first operand shall have scalar type. */
7288         semantic_condition(expression, "condition of conditional operator");
7289
7290         expression_t *true_expression = expression;
7291         bool          gnu_cond = false;
7292         if (GNU_MODE && token.kind == ':') {
7293                 gnu_cond = true;
7294         } else {
7295                 true_expression = parse_expression();
7296         }
7297         rem_anchor_token(':');
7298         expect(':');
7299         expression_t *false_expression =
7300                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7301
7302         type_t *const orig_true_type  = true_expression->base.type;
7303         type_t *const orig_false_type = false_expression->base.type;
7304         type_t *const true_type       = skip_typeref(orig_true_type);
7305         type_t *const false_type      = skip_typeref(orig_false_type);
7306
7307         /* 6.5.15.3 */
7308         source_position_t const *const pos = &conditional->base.source_position;
7309         type_t                        *result_type;
7310         if (is_type_void(true_type) || is_type_void(false_type)) {
7311                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7312                 if (true_expression->kind == EXPR_UNARY_THROW) {
7313                         result_type = false_type;
7314                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7315                         result_type = true_type;
7316                 } else {
7317                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7318                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7319                         }
7320                         result_type = type_void;
7321                 }
7322         } else if (is_type_arithmetic(true_type)
7323                    && is_type_arithmetic(false_type)) {
7324                 result_type = semantic_arithmetic(true_type, false_type);
7325         } else if (same_compound_type(true_type, false_type)) {
7326                 /* just take 1 of the 2 types */
7327                 result_type = true_type;
7328         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7329                 type_t *pointer_type;
7330                 type_t *other_type;
7331                 expression_t *other_expression;
7332                 if (is_type_pointer(true_type) &&
7333                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7334                         pointer_type     = true_type;
7335                         other_type       = false_type;
7336                         other_expression = false_expression;
7337                 } else {
7338                         pointer_type     = false_type;
7339                         other_type       = true_type;
7340                         other_expression = true_expression;
7341                 }
7342
7343                 if (is_null_pointer_constant(other_expression)) {
7344                         result_type = pointer_type;
7345                 } else if (is_type_pointer(other_type)) {
7346                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7347                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7348
7349                         type_t *to;
7350                         if (is_type_void(to1) || is_type_void(to2)) {
7351                                 to = type_void;
7352                         } else if (types_compatible(get_unqualified_type(to1),
7353                                                     get_unqualified_type(to2))) {
7354                                 to = to1;
7355                         } else {
7356                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7357                                 to = type_void;
7358                         }
7359
7360                         type_t *const type =
7361                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7362                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7363                 } else if (is_type_integer(other_type)) {
7364                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7365                         result_type = pointer_type;
7366                 } else {
7367                         goto types_incompatible;
7368                 }
7369         } else {
7370 types_incompatible:
7371                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7372                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7373                 }
7374                 result_type = type_error_type;
7375         }
7376
7377         conditional->true_expression
7378                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7379         conditional->false_expression
7380                 = create_implicit_cast(false_expression, result_type);
7381         conditional->base.type = result_type;
7382         return result;
7383 }
7384
7385 /**
7386  * Parse an extension expression.
7387  */
7388 static expression_t *parse_extension(void)
7389 {
7390         PUSH_EXTENSION();
7391         expression_t *expression = parse_subexpression(PREC_UNARY);
7392         POP_EXTENSION();
7393         return expression;
7394 }
7395
7396 /**
7397  * Parse a __builtin_classify_type() expression.
7398  */
7399 static expression_t *parse_builtin_classify_type(void)
7400 {
7401         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7402         result->base.type    = type_int;
7403
7404         eat(T___builtin_classify_type);
7405
7406         expect('(');
7407         add_anchor_token(')');
7408         expression_t *expression = parse_expression();
7409         rem_anchor_token(')');
7410         expect(')');
7411         result->classify_type.type_expression = expression;
7412
7413         return result;
7414 }
7415
7416 /**
7417  * Parse a delete expression
7418  * ISO/IEC 14882:1998(E) §5.3.5
7419  */
7420 static expression_t *parse_delete(void)
7421 {
7422         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7423         result->base.type          = type_void;
7424
7425         eat(T_delete);
7426
7427         if (next_if('[')) {
7428                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7429                 expect(']');
7430         }
7431
7432         expression_t *const value = parse_subexpression(PREC_CAST);
7433         result->unary.value = value;
7434
7435         type_t *const type = skip_typeref(value->base.type);
7436         if (!is_type_pointer(type)) {
7437                 if (is_type_valid(type)) {
7438                         errorf(&value->base.source_position,
7439                                         "operand of delete must have pointer type");
7440                 }
7441         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7442                 source_position_t const *const pos = &value->base.source_position;
7443                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7444         }
7445
7446         return result;
7447 }
7448
7449 /**
7450  * Parse a throw expression
7451  * ISO/IEC 14882:1998(E) §15:1
7452  */
7453 static expression_t *parse_throw(void)
7454 {
7455         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7456         result->base.type          = type_void;
7457
7458         eat(T_throw);
7459
7460         expression_t *value = NULL;
7461         switch (token.kind) {
7462                 EXPRESSION_START {
7463                         value = parse_assignment_expression();
7464                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7465                         type_t *const orig_type = value->base.type;
7466                         type_t *const type      = skip_typeref(orig_type);
7467                         if (is_type_incomplete(type)) {
7468                                 errorf(&value->base.source_position,
7469                                                 "cannot throw object of incomplete type '%T'", orig_type);
7470                         } else if (is_type_pointer(type)) {
7471                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7472                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7473                                         errorf(&value->base.source_position,
7474                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7475                                 }
7476                         }
7477                 }
7478
7479                 default:
7480                         break;
7481         }
7482         result->unary.value = value;
7483
7484         return result;
7485 }
7486
7487 static bool check_pointer_arithmetic(const source_position_t *source_position,
7488                                      type_t *pointer_type,
7489                                      type_t *orig_pointer_type)
7490 {
7491         type_t *points_to = pointer_type->pointer.points_to;
7492         points_to = skip_typeref(points_to);
7493
7494         if (is_type_incomplete(points_to)) {
7495                 if (!GNU_MODE || !is_type_void(points_to)) {
7496                         errorf(source_position,
7497                                "arithmetic with pointer to incomplete type '%T' not allowed",
7498                                orig_pointer_type);
7499                         return false;
7500                 } else {
7501                         warningf(WARN_POINTER_ARITH, source_position, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7502                 }
7503         } else if (is_type_function(points_to)) {
7504                 if (!GNU_MODE) {
7505                         errorf(source_position,
7506                                "arithmetic with pointer to function type '%T' not allowed",
7507                                orig_pointer_type);
7508                         return false;
7509                 } else {
7510                         warningf(WARN_POINTER_ARITH, source_position, "pointer to a function '%T' used in arithmetic", orig_pointer_type);
7511                 }
7512         }
7513         return true;
7514 }
7515
7516 static bool is_lvalue(const expression_t *expression)
7517 {
7518         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7519         switch (expression->kind) {
7520         case EXPR_ARRAY_ACCESS:
7521         case EXPR_COMPOUND_LITERAL:
7522         case EXPR_REFERENCE:
7523         case EXPR_SELECT:
7524         case EXPR_UNARY_DEREFERENCE:
7525                 return true;
7526
7527         default: {
7528                 type_t *type = skip_typeref(expression->base.type);
7529                 return
7530                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7531                         is_type_reference(type) ||
7532                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7533                          * error before, which maybe prevented properly recognizing it as
7534                          * lvalue. */
7535                         !is_type_valid(type);
7536         }
7537         }
7538 }
7539
7540 static void semantic_incdec(unary_expression_t *expression)
7541 {
7542         type_t *const orig_type = expression->value->base.type;
7543         type_t *const type      = skip_typeref(orig_type);
7544         if (is_type_pointer(type)) {
7545                 if (!check_pointer_arithmetic(&expression->base.source_position,
7546                                               type, orig_type)) {
7547                         return;
7548                 }
7549         } else if (!is_type_real(type) && is_type_valid(type)) {
7550                 /* TODO: improve error message */
7551                 errorf(&expression->base.source_position,
7552                        "operation needs an arithmetic or pointer type");
7553                 return;
7554         }
7555         if (!is_lvalue(expression->value)) {
7556                 /* TODO: improve error message */
7557                 errorf(&expression->base.source_position, "lvalue required as operand");
7558         }
7559         expression->base.type = orig_type;
7560 }
7561
7562 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7563 {
7564         type_t *const res_type = promote_integer(type);
7565         expr->base.type = res_type;
7566         expr->value     = create_implicit_cast(expr->value, res_type);
7567 }
7568
7569 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7570 {
7571         type_t *const orig_type = expression->value->base.type;
7572         type_t *const type      = skip_typeref(orig_type);
7573         if (!is_type_arithmetic(type)) {
7574                 if (is_type_valid(type)) {
7575                         /* TODO: improve error message */
7576                         errorf(&expression->base.source_position,
7577                                 "operation needs an arithmetic type");
7578                 }
7579                 return;
7580         } else if (is_type_integer(type)) {
7581                 promote_unary_int_expr(expression, type);
7582         } else {
7583                 expression->base.type = orig_type;
7584         }
7585 }
7586
7587 static void semantic_unexpr_plus(unary_expression_t *expression)
7588 {
7589         semantic_unexpr_arithmetic(expression);
7590         source_position_t const *const pos = &expression->base.source_position;
7591         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7592 }
7593
7594 static void semantic_not(unary_expression_t *expression)
7595 {
7596         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7597         semantic_condition(expression->value, "operand of !");
7598         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7599 }
7600
7601 static void semantic_unexpr_integer(unary_expression_t *expression)
7602 {
7603         type_t *const orig_type = expression->value->base.type;
7604         type_t *const type      = skip_typeref(orig_type);
7605         if (!is_type_integer(type)) {
7606                 if (is_type_valid(type)) {
7607                         errorf(&expression->base.source_position,
7608                                "operand of ~ must be of integer type");
7609                 }
7610                 return;
7611         }
7612
7613         promote_unary_int_expr(expression, type);
7614 }
7615
7616 static void semantic_dereference(unary_expression_t *expression)
7617 {
7618         type_t *const orig_type = expression->value->base.type;
7619         type_t *const type      = skip_typeref(orig_type);
7620         if (!is_type_pointer(type)) {
7621                 if (is_type_valid(type)) {
7622                         errorf(&expression->base.source_position,
7623                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7624                 }
7625                 return;
7626         }
7627
7628         type_t *result_type   = type->pointer.points_to;
7629         result_type           = automatic_type_conversion(result_type);
7630         expression->base.type = result_type;
7631 }
7632
7633 /**
7634  * Record that an address is taken (expression represents an lvalue).
7635  *
7636  * @param expression       the expression
7637  * @param may_be_register  if true, the expression might be an register
7638  */
7639 static void set_address_taken(expression_t *expression, bool may_be_register)
7640 {
7641         if (expression->kind != EXPR_REFERENCE)
7642                 return;
7643
7644         entity_t *const entity = expression->reference.entity;
7645
7646         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7647                 return;
7648
7649         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7650                         && !may_be_register) {
7651                 source_position_t const *const pos = &expression->base.source_position;
7652                 errorf(pos, "address of register '%N' requested", entity);
7653         }
7654
7655         entity->variable.address_taken = true;
7656 }
7657
7658 /**
7659  * Check the semantic of the address taken expression.
7660  */
7661 static void semantic_take_addr(unary_expression_t *expression)
7662 {
7663         expression_t *value = expression->value;
7664         value->base.type    = revert_automatic_type_conversion(value);
7665
7666         type_t *orig_type = value->base.type;
7667         type_t *type      = skip_typeref(orig_type);
7668         if (!is_type_valid(type))
7669                 return;
7670
7671         /* §6.5.3.2 */
7672         if (!is_lvalue(value)) {
7673                 errorf(&expression->base.source_position, "'&' requires an lvalue");
7674         }
7675         if (is_bitfield(value)) {
7676                 errorf(&expression->base.source_position,
7677                        "'&' not allowed on bitfield");
7678         }
7679
7680         set_address_taken(value, false);
7681
7682         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7683 }
7684
7685 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7686 static expression_t *parse_##unexpression_type(void)                         \
7687 {                                                                            \
7688         expression_t *unary_expression                                           \
7689                 = allocate_expression_zero(unexpression_type);                       \
7690         eat(token_kind);                                                         \
7691         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7692                                                                                  \
7693         sfunc(&unary_expression->unary);                                         \
7694                                                                                  \
7695         return unary_expression;                                                 \
7696 }
7697
7698 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7699                                semantic_unexpr_arithmetic)
7700 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7701                                semantic_unexpr_plus)
7702 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7703                                semantic_not)
7704 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7705                                semantic_dereference)
7706 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7707                                semantic_take_addr)
7708 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7709                                semantic_unexpr_integer)
7710 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7711                                semantic_incdec)
7712 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7713                                semantic_incdec)
7714
7715 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7716                                                sfunc)                         \
7717 static expression_t *parse_##unexpression_type(expression_t *left)            \
7718 {                                                                             \
7719         expression_t *unary_expression                                            \
7720                 = allocate_expression_zero(unexpression_type);                        \
7721         eat(token_kind);                                                          \
7722         unary_expression->unary.value = left;                                     \
7723                                                                                   \
7724         sfunc(&unary_expression->unary);                                          \
7725                                                                               \
7726         return unary_expression;                                                  \
7727 }
7728
7729 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7730                                        EXPR_UNARY_POSTFIX_INCREMENT,
7731                                        semantic_incdec)
7732 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7733                                        EXPR_UNARY_POSTFIX_DECREMENT,
7734                                        semantic_incdec)
7735
7736 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7737 {
7738         /* TODO: handle complex + imaginary types */
7739
7740         type_left  = get_unqualified_type(type_left);
7741         type_right = get_unqualified_type(type_right);
7742
7743         /* §6.3.1.8 Usual arithmetic conversions */
7744         if (type_left == type_long_double || type_right == type_long_double) {
7745                 return type_long_double;
7746         } else if (type_left == type_double || type_right == type_double) {
7747                 return type_double;
7748         } else if (type_left == type_float || type_right == type_float) {
7749                 return type_float;
7750         }
7751
7752         type_left  = promote_integer(type_left);
7753         type_right = promote_integer(type_right);
7754
7755         if (type_left == type_right)
7756                 return type_left;
7757
7758         bool     const signed_left  = is_type_signed(type_left);
7759         bool     const signed_right = is_type_signed(type_right);
7760         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7761         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7762
7763         if (signed_left == signed_right)
7764                 return rank_left >= rank_right ? type_left : type_right;
7765
7766         unsigned           s_rank;
7767         unsigned           u_rank;
7768         atomic_type_kind_t s_akind;
7769         atomic_type_kind_t u_akind;
7770         type_t *s_type;
7771         type_t *u_type;
7772         if (signed_left) {
7773                 s_type = type_left;
7774                 u_type = type_right;
7775         } else {
7776                 s_type = type_right;
7777                 u_type = type_left;
7778         }
7779         s_akind = get_akind(s_type);
7780         u_akind = get_akind(u_type);
7781         s_rank  = get_akind_rank(s_akind);
7782         u_rank  = get_akind_rank(u_akind);
7783
7784         if (u_rank >= s_rank)
7785                 return u_type;
7786
7787         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7788                 return s_type;
7789
7790         switch (s_akind) {
7791         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7792         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7793         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7794
7795         default: panic("invalid atomic type");
7796         }
7797 }
7798
7799 /**
7800  * Check the semantic restrictions for a binary expression.
7801  */
7802 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7803 {
7804         expression_t *const left            = expression->left;
7805         expression_t *const right           = expression->right;
7806         type_t       *const orig_type_left  = left->base.type;
7807         type_t       *const orig_type_right = right->base.type;
7808         type_t       *const type_left       = skip_typeref(orig_type_left);
7809         type_t       *const type_right      = skip_typeref(orig_type_right);
7810
7811         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7812                 /* TODO: improve error message */
7813                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7814                         errorf(&expression->base.source_position,
7815                                "operation needs arithmetic types");
7816                 }
7817                 return;
7818         }
7819
7820         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7821         expression->left      = create_implicit_cast(left, arithmetic_type);
7822         expression->right     = create_implicit_cast(right, arithmetic_type);
7823         expression->base.type = arithmetic_type;
7824 }
7825
7826 static void semantic_binexpr_integer(binary_expression_t *const expression)
7827 {
7828         expression_t *const left            = expression->left;
7829         expression_t *const right           = expression->right;
7830         type_t       *const orig_type_left  = left->base.type;
7831         type_t       *const orig_type_right = right->base.type;
7832         type_t       *const type_left       = skip_typeref(orig_type_left);
7833         type_t       *const type_right      = skip_typeref(orig_type_right);
7834
7835         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7836                 /* TODO: improve error message */
7837                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7838                         errorf(&expression->base.source_position,
7839                                "operation needs integer types");
7840                 }
7841                 return;
7842         }
7843
7844         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7845         expression->left      = create_implicit_cast(left, result_type);
7846         expression->right     = create_implicit_cast(right, result_type);
7847         expression->base.type = result_type;
7848 }
7849
7850 static void warn_div_by_zero(binary_expression_t const *const expression)
7851 {
7852         if (!is_type_integer(expression->base.type))
7853                 return;
7854
7855         expression_t const *const right = expression->right;
7856         /* The type of the right operand can be different for /= */
7857         if (is_type_integer(right->base.type)                    &&
7858             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7859             !fold_constant_to_bool(right)) {
7860                 source_position_t const *const pos = &expression->base.source_position;
7861                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7862         }
7863 }
7864
7865 /**
7866  * Check the semantic restrictions for a div/mod expression.
7867  */
7868 static void semantic_divmod_arithmetic(binary_expression_t *expression)
7869 {
7870         semantic_binexpr_arithmetic(expression);
7871         warn_div_by_zero(expression);
7872 }
7873
7874 static void warn_addsub_in_shift(const expression_t *const expr)
7875 {
7876         if (expr->base.parenthesized)
7877                 return;
7878
7879         char op;
7880         switch (expr->kind) {
7881                 case EXPR_BINARY_ADD: op = '+'; break;
7882                 case EXPR_BINARY_SUB: op = '-'; break;
7883                 default:              return;
7884         }
7885
7886         source_position_t const *const pos = &expr->base.source_position;
7887         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7888 }
7889
7890 static bool semantic_shift(binary_expression_t *expression)
7891 {
7892         expression_t *const left            = expression->left;
7893         expression_t *const right           = expression->right;
7894         type_t       *const orig_type_left  = left->base.type;
7895         type_t       *const orig_type_right = right->base.type;
7896         type_t       *      type_left       = skip_typeref(orig_type_left);
7897         type_t       *      type_right      = skip_typeref(orig_type_right);
7898
7899         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7900                 /* TODO: improve error message */
7901                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7902                         errorf(&expression->base.source_position,
7903                                "operands of shift operation must have integer types");
7904                 }
7905                 return false;
7906         }
7907
7908         type_left = promote_integer(type_left);
7909
7910         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7911                 source_position_t const *const pos   = &right->base.source_position;
7912                 long                     const count = fold_constant_to_int(right);
7913                 if (count < 0) {
7914                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7915                 } else if ((unsigned long)count >=
7916                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7917                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7918                 }
7919         }
7920
7921         type_right        = promote_integer(type_right);
7922         expression->right = create_implicit_cast(right, type_right);
7923
7924         return true;
7925 }
7926
7927 static void semantic_shift_op(binary_expression_t *expression)
7928 {
7929         expression_t *const left  = expression->left;
7930         expression_t *const right = expression->right;
7931
7932         if (!semantic_shift(expression))
7933                 return;
7934
7935         warn_addsub_in_shift(left);
7936         warn_addsub_in_shift(right);
7937
7938         type_t *const orig_type_left = left->base.type;
7939         type_t *      type_left      = skip_typeref(orig_type_left);
7940
7941         type_left             = promote_integer(type_left);
7942         expression->left      = create_implicit_cast(left, type_left);
7943         expression->base.type = type_left;
7944 }
7945
7946 static void semantic_add(binary_expression_t *expression)
7947 {
7948         expression_t *const left            = expression->left;
7949         expression_t *const right           = expression->right;
7950         type_t       *const orig_type_left  = left->base.type;
7951         type_t       *const orig_type_right = right->base.type;
7952         type_t       *const type_left       = skip_typeref(orig_type_left);
7953         type_t       *const type_right      = skip_typeref(orig_type_right);
7954
7955         /* §6.5.6 */
7956         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7957                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7958                 expression->left  = create_implicit_cast(left, arithmetic_type);
7959                 expression->right = create_implicit_cast(right, arithmetic_type);
7960                 expression->base.type = arithmetic_type;
7961         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7962                 check_pointer_arithmetic(&expression->base.source_position,
7963                                          type_left, orig_type_left);
7964                 expression->base.type = type_left;
7965         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7966                 check_pointer_arithmetic(&expression->base.source_position,
7967                                          type_right, orig_type_right);
7968                 expression->base.type = type_right;
7969         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7970                 errorf(&expression->base.source_position,
7971                        "invalid operands to binary + ('%T', '%T')",
7972                        orig_type_left, orig_type_right);
7973         }
7974 }
7975
7976 static void semantic_sub(binary_expression_t *expression)
7977 {
7978         expression_t            *const left            = expression->left;
7979         expression_t            *const right           = expression->right;
7980         type_t                  *const orig_type_left  = left->base.type;
7981         type_t                  *const orig_type_right = right->base.type;
7982         type_t                  *const type_left       = skip_typeref(orig_type_left);
7983         type_t                  *const type_right      = skip_typeref(orig_type_right);
7984         source_position_t const *const pos             = &expression->base.source_position;
7985
7986         /* §5.6.5 */
7987         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7988                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7989                 expression->left        = create_implicit_cast(left, arithmetic_type);
7990                 expression->right       = create_implicit_cast(right, arithmetic_type);
7991                 expression->base.type =  arithmetic_type;
7992         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7993                 check_pointer_arithmetic(&expression->base.source_position,
7994                                          type_left, orig_type_left);
7995                 expression->base.type = type_left;
7996         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7997                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7998                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7999                 if (!types_compatible(unqual_left, unqual_right)) {
8000                         errorf(pos,
8001                                "subtracting pointers to incompatible types '%T' and '%T'",
8002                                orig_type_left, orig_type_right);
8003                 } else if (!is_type_object(unqual_left)) {
8004                         if (!is_type_void(unqual_left)) {
8005                                 errorf(pos, "subtracting pointers to non-object types '%T'",
8006                                        orig_type_left);
8007                         } else {
8008                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
8009                         }
8010                 }
8011                 expression->base.type = type_ptrdiff_t;
8012         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8013                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
8014                        orig_type_left, orig_type_right);
8015         }
8016 }
8017
8018 static void warn_string_literal_address(expression_t const* expr)
8019 {
8020         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
8021                 expr = expr->unary.value;
8022                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
8023                         return;
8024                 expr = expr->unary.value;
8025         }
8026
8027         if (expr->kind == EXPR_STRING_LITERAL
8028                         || expr->kind == EXPR_WIDE_STRING_LITERAL) {
8029                 source_position_t const *const pos = &expr->base.source_position;
8030                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8031         }
8032 }
8033
8034 static bool maybe_negative(expression_t const *const expr)
8035 {
8036         switch (is_constant_expression(expr)) {
8037                 case EXPR_CLASS_ERROR:    return false;
8038                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8039                 default:                  return true;
8040         }
8041 }
8042
8043 static void warn_comparison(source_position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8044 {
8045         warn_string_literal_address(expr);
8046
8047         expression_t const* const ref = get_reference_address(expr);
8048         if (ref != NULL && is_null_pointer_constant(other)) {
8049                 entity_t const *const ent = ref->reference.entity;
8050                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8051         }
8052
8053         if (!expr->base.parenthesized) {
8054                 switch (expr->base.kind) {
8055                         case EXPR_BINARY_LESS:
8056                         case EXPR_BINARY_GREATER:
8057                         case EXPR_BINARY_LESSEQUAL:
8058                         case EXPR_BINARY_GREATEREQUAL:
8059                         case EXPR_BINARY_NOTEQUAL:
8060                         case EXPR_BINARY_EQUAL:
8061                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8062                                 break;
8063                         default:
8064                                 break;
8065                 }
8066         }
8067 }
8068
8069 /**
8070  * Check the semantics of comparison expressions.
8071  *
8072  * @param expression   The expression to check.
8073  */
8074 static void semantic_comparison(binary_expression_t *expression)
8075 {
8076         source_position_t const *const pos   = &expression->base.source_position;
8077         expression_t            *const left  = expression->left;
8078         expression_t            *const right = expression->right;
8079
8080         warn_comparison(pos, left, right);
8081         warn_comparison(pos, right, left);
8082
8083         type_t *orig_type_left  = left->base.type;
8084         type_t *orig_type_right = right->base.type;
8085         type_t *type_left       = skip_typeref(orig_type_left);
8086         type_t *type_right      = skip_typeref(orig_type_right);
8087
8088         /* TODO non-arithmetic types */
8089         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8090                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8091
8092                 /* test for signed vs unsigned compares */
8093                 if (is_type_integer(arithmetic_type)) {
8094                         bool const signed_left  = is_type_signed(type_left);
8095                         bool const signed_right = is_type_signed(type_right);
8096                         if (signed_left != signed_right) {
8097                                 /* FIXME long long needs better const folding magic */
8098                                 /* TODO check whether constant value can be represented by other type */
8099                                 if ((signed_left  && maybe_negative(left)) ||
8100                                                 (signed_right && maybe_negative(right))) {
8101                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8102                                 }
8103                         }
8104                 }
8105
8106                 expression->left        = create_implicit_cast(left, arithmetic_type);
8107                 expression->right       = create_implicit_cast(right, arithmetic_type);
8108                 expression->base.type   = arithmetic_type;
8109                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8110                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8111                     is_type_float(arithmetic_type)) {
8112                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8113                 }
8114         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8115                 /* TODO check compatibility */
8116         } else if (is_type_pointer(type_left)) {
8117                 expression->right = create_implicit_cast(right, type_left);
8118         } else if (is_type_pointer(type_right)) {
8119                 expression->left = create_implicit_cast(left, type_right);
8120         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8121                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8122         }
8123         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8124 }
8125
8126 /**
8127  * Checks if a compound type has constant fields.
8128  */
8129 static bool has_const_fields(const compound_type_t *type)
8130 {
8131         compound_t *compound = type->compound;
8132         entity_t   *entry    = compound->members.entities;
8133
8134         for (; entry != NULL; entry = entry->base.next) {
8135                 if (!is_declaration(entry))
8136                         continue;
8137
8138                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8139                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8140                         return true;
8141         }
8142
8143         return false;
8144 }
8145
8146 static bool is_valid_assignment_lhs(expression_t const* const left)
8147 {
8148         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8149         type_t *const type_left      = skip_typeref(orig_type_left);
8150
8151         if (!is_lvalue(left)) {
8152                 errorf(&left->base.source_position, "left hand side '%E' of assignment is not an lvalue",
8153                        left);
8154                 return false;
8155         }
8156
8157         if (left->kind == EXPR_REFERENCE
8158                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8159                 errorf(&left->base.source_position, "cannot assign to function '%E'", left);
8160                 return false;
8161         }
8162
8163         if (is_type_array(type_left)) {
8164                 errorf(&left->base.source_position, "cannot assign to array '%E'", left);
8165                 return false;
8166         }
8167         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8168                 errorf(&left->base.source_position, "assignment to read-only location '%E' (type '%T')", left,
8169                        orig_type_left);
8170                 return false;
8171         }
8172         if (is_type_incomplete(type_left)) {
8173                 errorf(&left->base.source_position, "left-hand side '%E' of assignment has incomplete type '%T'",
8174                        left, orig_type_left);
8175                 return false;
8176         }
8177         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8178                 errorf(&left->base.source_position, "cannot assign to '%E' because compound type '%T' has read-only fields",
8179                        left, orig_type_left);
8180                 return false;
8181         }
8182
8183         return true;
8184 }
8185
8186 static void semantic_arithmetic_assign(binary_expression_t *expression)
8187 {
8188         expression_t *left            = expression->left;
8189         expression_t *right           = expression->right;
8190         type_t       *orig_type_left  = left->base.type;
8191         type_t       *orig_type_right = right->base.type;
8192
8193         if (!is_valid_assignment_lhs(left))
8194                 return;
8195
8196         type_t *type_left  = skip_typeref(orig_type_left);
8197         type_t *type_right = skip_typeref(orig_type_right);
8198
8199         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8200                 /* TODO: improve error message */
8201                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8202                         errorf(&expression->base.source_position,
8203                                "operation needs arithmetic types");
8204                 }
8205                 return;
8206         }
8207
8208         /* combined instructions are tricky. We can't create an implicit cast on
8209          * the left side, because we need the uncasted form for the store.
8210          * The ast2firm pass has to know that left_type must be right_type
8211          * for the arithmetic operation and create a cast by itself */
8212         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8213         expression->right       = create_implicit_cast(right, arithmetic_type);
8214         expression->base.type   = type_left;
8215 }
8216
8217 static void semantic_divmod_assign(binary_expression_t *expression)
8218 {
8219         semantic_arithmetic_assign(expression);
8220         warn_div_by_zero(expression);
8221 }
8222
8223 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8224 {
8225         expression_t *const left            = expression->left;
8226         expression_t *const right           = expression->right;
8227         type_t       *const orig_type_left  = left->base.type;
8228         type_t       *const orig_type_right = right->base.type;
8229         type_t       *const type_left       = skip_typeref(orig_type_left);
8230         type_t       *const type_right      = skip_typeref(orig_type_right);
8231
8232         if (!is_valid_assignment_lhs(left))
8233                 return;
8234
8235         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8236                 /* combined instructions are tricky. We can't create an implicit cast on
8237                  * the left side, because we need the uncasted form for the store.
8238                  * The ast2firm pass has to know that left_type must be right_type
8239                  * for the arithmetic operation and create a cast by itself */
8240                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8241                 expression->right     = create_implicit_cast(right, arithmetic_type);
8242                 expression->base.type = type_left;
8243         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8244                 check_pointer_arithmetic(&expression->base.source_position,
8245                                          type_left, orig_type_left);
8246                 expression->base.type = type_left;
8247         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8248                 errorf(&expression->base.source_position,
8249                        "incompatible types '%T' and '%T' in assignment",
8250                        orig_type_left, orig_type_right);
8251         }
8252 }
8253
8254 static void semantic_integer_assign(binary_expression_t *expression)
8255 {
8256         expression_t *left            = expression->left;
8257         expression_t *right           = expression->right;
8258         type_t       *orig_type_left  = left->base.type;
8259         type_t       *orig_type_right = right->base.type;
8260
8261         if (!is_valid_assignment_lhs(left))
8262                 return;
8263
8264         type_t *type_left  = skip_typeref(orig_type_left);
8265         type_t *type_right = skip_typeref(orig_type_right);
8266
8267         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8268                 /* TODO: improve error message */
8269                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8270                         errorf(&expression->base.source_position,
8271                                "operation needs integer types");
8272                 }
8273                 return;
8274         }
8275
8276         /* combined instructions are tricky. We can't create an implicit cast on
8277          * the left side, because we need the uncasted form for the store.
8278          * The ast2firm pass has to know that left_type must be right_type
8279          * for the arithmetic operation and create a cast by itself */
8280         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8281         expression->right       = create_implicit_cast(right, arithmetic_type);
8282         expression->base.type   = type_left;
8283 }
8284
8285 static void semantic_shift_assign(binary_expression_t *expression)
8286 {
8287         expression_t *left           = expression->left;
8288
8289         if (!is_valid_assignment_lhs(left))
8290                 return;
8291
8292         if (!semantic_shift(expression))
8293                 return;
8294
8295         expression->base.type = skip_typeref(left->base.type);
8296 }
8297
8298 static void warn_logical_and_within_or(const expression_t *const expr)
8299 {
8300         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8301                 return;
8302         if (expr->base.parenthesized)
8303                 return;
8304         source_position_t const *const pos = &expr->base.source_position;
8305         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8306 }
8307
8308 /**
8309  * Check the semantic restrictions of a logical expression.
8310  */
8311 static void semantic_logical_op(binary_expression_t *expression)
8312 {
8313         /* §6.5.13:2  Each of the operands shall have scalar type.
8314          * §6.5.14:2  Each of the operands shall have scalar type. */
8315         semantic_condition(expression->left,   "left operand of logical operator");
8316         semantic_condition(expression->right, "right operand of logical operator");
8317         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8318                 warn_logical_and_within_or(expression->left);
8319                 warn_logical_and_within_or(expression->right);
8320         }
8321         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8322 }
8323
8324 /**
8325  * Check the semantic restrictions of a binary assign expression.
8326  */
8327 static void semantic_binexpr_assign(binary_expression_t *expression)
8328 {
8329         expression_t *left           = expression->left;
8330         type_t       *orig_type_left = left->base.type;
8331
8332         if (!is_valid_assignment_lhs(left))
8333                 return;
8334
8335         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8336         report_assign_error(error, orig_type_left, expression->right,
8337                         "assignment", &left->base.source_position);
8338         expression->right = create_implicit_cast(expression->right, orig_type_left);
8339         expression->base.type = orig_type_left;
8340 }
8341
8342 /**
8343  * Determine if the outermost operation (or parts thereof) of the given
8344  * expression has no effect in order to generate a warning about this fact.
8345  * Therefore in some cases this only examines some of the operands of the
8346  * expression (see comments in the function and examples below).
8347  * Examples:
8348  *   f() + 23;    // warning, because + has no effect
8349  *   x || f();    // no warning, because x controls execution of f()
8350  *   x ? y : f(); // warning, because y has no effect
8351  *   (void)x;     // no warning to be able to suppress the warning
8352  * This function can NOT be used for an "expression has definitely no effect"-
8353  * analysis. */
8354 static bool expression_has_effect(const expression_t *const expr)
8355 {
8356         switch (expr->kind) {
8357                 case EXPR_ERROR:                      return true; /* do NOT warn */
8358                 case EXPR_REFERENCE:                  return false;
8359                 case EXPR_ENUM_CONSTANT:              return false;
8360                 case EXPR_LABEL_ADDRESS:              return false;
8361
8362                 /* suppress the warning for microsoft __noop operations */
8363                 case EXPR_LITERAL_MS_NOOP:            return true;
8364                 case EXPR_LITERAL_BOOLEAN:
8365                 case EXPR_LITERAL_CHARACTER:
8366                 case EXPR_LITERAL_WIDE_CHARACTER:
8367                 case EXPR_LITERAL_INTEGER:
8368                 case EXPR_LITERAL_FLOATINGPOINT:
8369                 case EXPR_STRING_LITERAL:             return false;
8370                 case EXPR_WIDE_STRING_LITERAL:        return false;
8371
8372                 case EXPR_CALL: {
8373                         const call_expression_t *const call = &expr->call;
8374                         if (call->function->kind != EXPR_REFERENCE)
8375                                 return true;
8376
8377                         switch (call->function->reference.entity->function.btk) {
8378                                 /* FIXME: which builtins have no effect? */
8379                                 default:                      return true;
8380                         }
8381                 }
8382
8383                 /* Generate the warning if either the left or right hand side of a
8384                  * conditional expression has no effect */
8385                 case EXPR_CONDITIONAL: {
8386                         conditional_expression_t const *const cond = &expr->conditional;
8387                         expression_t             const *const t    = cond->true_expression;
8388                         return
8389                                 (t == NULL || expression_has_effect(t)) &&
8390                                 expression_has_effect(cond->false_expression);
8391                 }
8392
8393                 case EXPR_SELECT:                     return false;
8394                 case EXPR_ARRAY_ACCESS:               return false;
8395                 case EXPR_SIZEOF:                     return false;
8396                 case EXPR_CLASSIFY_TYPE:              return false;
8397                 case EXPR_ALIGNOF:                    return false;
8398
8399                 case EXPR_FUNCNAME:                   return false;
8400                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8401                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8402                 case EXPR_OFFSETOF:                   return false;
8403                 case EXPR_VA_START:                   return true;
8404                 case EXPR_VA_ARG:                     return true;
8405                 case EXPR_VA_COPY:                    return true;
8406                 case EXPR_STATEMENT:                  return true; // TODO
8407                 case EXPR_COMPOUND_LITERAL:           return false;
8408
8409                 case EXPR_UNARY_NEGATE:               return false;
8410                 case EXPR_UNARY_PLUS:                 return false;
8411                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8412                 case EXPR_UNARY_NOT:                  return false;
8413                 case EXPR_UNARY_DEREFERENCE:          return false;
8414                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8415                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8416                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8417                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8418                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8419
8420                 /* Treat void casts as if they have an effect in order to being able to
8421                  * suppress the warning */
8422                 case EXPR_UNARY_CAST: {
8423                         type_t *const type = skip_typeref(expr->base.type);
8424                         return is_type_void(type);
8425                 }
8426
8427                 case EXPR_UNARY_ASSUME:               return true;
8428                 case EXPR_UNARY_DELETE:               return true;
8429                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8430                 case EXPR_UNARY_THROW:                return true;
8431
8432                 case EXPR_BINARY_ADD:                 return false;
8433                 case EXPR_BINARY_SUB:                 return false;
8434                 case EXPR_BINARY_MUL:                 return false;
8435                 case EXPR_BINARY_DIV:                 return false;
8436                 case EXPR_BINARY_MOD:                 return false;
8437                 case EXPR_BINARY_EQUAL:               return false;
8438                 case EXPR_BINARY_NOTEQUAL:            return false;
8439                 case EXPR_BINARY_LESS:                return false;
8440                 case EXPR_BINARY_LESSEQUAL:           return false;
8441                 case EXPR_BINARY_GREATER:             return false;
8442                 case EXPR_BINARY_GREATEREQUAL:        return false;
8443                 case EXPR_BINARY_BITWISE_AND:         return false;
8444                 case EXPR_BINARY_BITWISE_OR:          return false;
8445                 case EXPR_BINARY_BITWISE_XOR:         return false;
8446                 case EXPR_BINARY_SHIFTLEFT:           return false;
8447                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8448                 case EXPR_BINARY_ASSIGN:              return true;
8449                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8450                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8451                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8452                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8453                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8454                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8455                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8456                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8457                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8458                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8459
8460                 /* Only examine the right hand side of && and ||, because the left hand
8461                  * side already has the effect of controlling the execution of the right
8462                  * hand side */
8463                 case EXPR_BINARY_LOGICAL_AND:
8464                 case EXPR_BINARY_LOGICAL_OR:
8465                 /* Only examine the right hand side of a comma expression, because the left
8466                  * hand side has a separate warning */
8467                 case EXPR_BINARY_COMMA:
8468                         return expression_has_effect(expr->binary.right);
8469
8470                 case EXPR_BINARY_ISGREATER:           return false;
8471                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8472                 case EXPR_BINARY_ISLESS:              return false;
8473                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8474                 case EXPR_BINARY_ISLESSGREATER:       return false;
8475                 case EXPR_BINARY_ISUNORDERED:         return false;
8476         }
8477
8478         internal_errorf(HERE, "unexpected expression");
8479 }
8480
8481 static void semantic_comma(binary_expression_t *expression)
8482 {
8483         const expression_t *const left = expression->left;
8484         if (!expression_has_effect(left)) {
8485                 source_position_t const *const pos = &left->base.source_position;
8486                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8487         }
8488         expression->base.type = expression->right->base.type;
8489 }
8490
8491 /**
8492  * @param prec_r precedence of the right operand
8493  */
8494 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8495 static expression_t *parse_##binexpression_type(expression_t *left)          \
8496 {                                                                            \
8497         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8498         binexpr->binary.left  = left;                                            \
8499         eat(token_kind);                                                         \
8500                                                                              \
8501         expression_t *right = parse_subexpression(prec_r);                       \
8502                                                                              \
8503         binexpr->binary.right = right;                                           \
8504         sfunc(&binexpr->binary);                                                 \
8505                                                                              \
8506         return binexpr;                                                          \
8507 }
8508
8509 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8510 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_divmod_arithmetic)
8511 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_divmod_arithmetic)
8512 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8513 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8514 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8515 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8516 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8517 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8518 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8519 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8520 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8521 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8522 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8523 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8524 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8525 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8526 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8527 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8528 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8529 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8530 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8531 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8532 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8533 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8534 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8535 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8536 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8537 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8538 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8539
8540
8541 static expression_t *parse_subexpression(precedence_t precedence)
8542 {
8543         expression_parser_function_t *parser
8544                 = &expression_parsers[token.kind];
8545         expression_t                 *left;
8546
8547         if (parser->parser != NULL) {
8548                 left = parser->parser();
8549         } else {
8550                 left = parse_primary_expression();
8551         }
8552         assert(left != NULL);
8553
8554         while (true) {
8555                 parser = &expression_parsers[token.kind];
8556                 if (parser->infix_parser == NULL)
8557                         break;
8558                 if (parser->infix_precedence < precedence)
8559                         break;
8560
8561                 left = parser->infix_parser(left);
8562
8563                 assert(left != NULL);
8564         }
8565
8566         return left;
8567 }
8568
8569 /**
8570  * Parse an expression.
8571  */
8572 static expression_t *parse_expression(void)
8573 {
8574         return parse_subexpression(PREC_EXPRESSION);
8575 }
8576
8577 /**
8578  * Register a parser for a prefix-like operator.
8579  *
8580  * @param parser      the parser function
8581  * @param token_kind  the token type of the prefix token
8582  */
8583 static void register_expression_parser(parse_expression_function parser,
8584                                        int token_kind)
8585 {
8586         expression_parser_function_t *entry = &expression_parsers[token_kind];
8587
8588         if (entry->parser != NULL) {
8589                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8590                 panic("trying to register multiple expression parsers for a token");
8591         }
8592         entry->parser = parser;
8593 }
8594
8595 /**
8596  * Register a parser for an infix operator with given precedence.
8597  *
8598  * @param parser      the parser function
8599  * @param token_kind  the token type of the infix operator
8600  * @param precedence  the precedence of the operator
8601  */
8602 static void register_infix_parser(parse_expression_infix_function parser,
8603                                   int token_kind, precedence_t precedence)
8604 {
8605         expression_parser_function_t *entry = &expression_parsers[token_kind];
8606
8607         if (entry->infix_parser != NULL) {
8608                 diagnosticf("for token '%k'\n", (token_kind_t)token_kind);
8609                 panic("trying to register multiple infix expression parsers for a "
8610                       "token");
8611         }
8612         entry->infix_parser     = parser;
8613         entry->infix_precedence = precedence;
8614 }
8615
8616 /**
8617  * Initialize the expression parsers.
8618  */
8619 static void init_expression_parsers(void)
8620 {
8621         memset(&expression_parsers, 0, sizeof(expression_parsers));
8622
8623         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8624         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8625         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8626         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8627         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8628         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8629         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8630         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8631         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8632         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8633         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8634         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8635         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8636         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8637         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8638         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8639         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8640         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8641         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8642         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8643         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8644         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8645         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8646         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8647         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8648         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8649         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8650         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8651         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8652         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8653         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8654         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8655         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8656         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8657         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8658         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8659         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8660
8661         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8662         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8663         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8664         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8665         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8666         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8667         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8668         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8669         register_expression_parser(parse_sizeof,                      T_sizeof);
8670         register_expression_parser(parse_alignof,                     T___alignof__);
8671         register_expression_parser(parse_extension,                   T___extension__);
8672         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8673         register_expression_parser(parse_delete,                      T_delete);
8674         register_expression_parser(parse_throw,                       T_throw);
8675 }
8676
8677 /**
8678  * Parse a asm statement arguments specification.
8679  */
8680 static asm_argument_t *parse_asm_arguments(bool is_out)
8681 {
8682         asm_argument_t  *result = NULL;
8683         asm_argument_t **anchor = &result;
8684
8685         while (token.kind == T_STRING_LITERAL || token.kind == '[') {
8686                 asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8687
8688                 if (next_if('[')) {
8689                         add_anchor_token(']');
8690                         argument->symbol = expect_identifier("while parsing asm argument", NULL);
8691                         rem_anchor_token(']');
8692                         expect(']');
8693                         if (!argument->symbol)
8694                                 return NULL;
8695                 }
8696
8697                 argument->constraints = parse_string_literals();
8698                 expect('(');
8699                 add_anchor_token(')');
8700                 expression_t *expression = parse_expression();
8701                 rem_anchor_token(')');
8702                 if (is_out) {
8703                         /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8704                          * change size or type representation (e.g. int -> long is ok, but
8705                          * int -> float is not) */
8706                         if (expression->kind == EXPR_UNARY_CAST) {
8707                                 type_t      *const type = expression->base.type;
8708                                 type_kind_t  const kind = type->kind;
8709                                 if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8710                                         unsigned flags;
8711                                         unsigned size;
8712                                         if (kind == TYPE_ATOMIC) {
8713                                                 atomic_type_kind_t const akind = type->atomic.akind;
8714                                                 flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8715                                                 size  = get_atomic_type_size(akind);
8716                                         } else {
8717                                                 flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8718                                                 size  = get_type_size(type_void_ptr);
8719                                         }
8720
8721                                         do {
8722                                                 expression_t *const value      = expression->unary.value;
8723                                                 type_t       *const value_type = value->base.type;
8724                                                 type_kind_t   const value_kind = value_type->kind;
8725
8726                                                 unsigned value_flags;
8727                                                 unsigned value_size;
8728                                                 if (value_kind == TYPE_ATOMIC) {
8729                                                         atomic_type_kind_t const value_akind = value_type->atomic.akind;
8730                                                         value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8731                                                         value_size  = get_atomic_type_size(value_akind);
8732                                                 } else if (value_kind == TYPE_POINTER) {
8733                                                         value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8734                                                         value_size  = get_type_size(type_void_ptr);
8735                                                 } else {
8736                                                         break;
8737                                                 }
8738
8739                                                 if (value_flags != flags || value_size != size)
8740                                                         break;
8741
8742                                                 expression = value;
8743                                         } while (expression->kind == EXPR_UNARY_CAST);
8744                                 }
8745                         }
8746
8747                         if (!is_lvalue(expression)) {
8748                                 errorf(&expression->base.source_position,
8749                                        "asm output argument is not an lvalue");
8750                         }
8751
8752                         if (argument->constraints.begin[0] == '=')
8753                                 determine_lhs_ent(expression, NULL);
8754                         else
8755                                 mark_vars_read(expression, NULL);
8756                 } else {
8757                         mark_vars_read(expression, NULL);
8758                 }
8759                 argument->expression = expression;
8760                 expect(')');
8761
8762                 set_address_taken(expression, true);
8763
8764                 *anchor = argument;
8765                 anchor  = &argument->next;
8766
8767                 if (!next_if(','))
8768                         break;
8769         }
8770
8771         return result;
8772 }
8773
8774 /**
8775  * Parse a asm statement clobber specification.
8776  */
8777 static asm_clobber_t *parse_asm_clobbers(void)
8778 {
8779         asm_clobber_t *result  = NULL;
8780         asm_clobber_t **anchor = &result;
8781
8782         while (token.kind == T_STRING_LITERAL) {
8783                 asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8784                 clobber->clobber       = parse_string_literals();
8785
8786                 *anchor = clobber;
8787                 anchor  = &clobber->next;
8788
8789                 if (!next_if(','))
8790                         break;
8791         }
8792
8793         return result;
8794 }
8795
8796 /**
8797  * Parse an asm statement.
8798  */
8799 static statement_t *parse_asm_statement(void)
8800 {
8801         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8802         asm_statement_t *asm_statement = &statement->asms;
8803
8804         eat(T_asm);
8805
8806         if (next_if(T_volatile))
8807                 asm_statement->is_volatile = true;
8808
8809         expect('(');
8810         add_anchor_token(')');
8811         if (token.kind != T_STRING_LITERAL) {
8812                 parse_error_expected("after asm(", T_STRING_LITERAL, NULL);
8813                 goto end_of_asm;
8814         }
8815         asm_statement->asm_text = parse_string_literals();
8816
8817         add_anchor_token(':');
8818         if (!next_if(':')) {
8819                 rem_anchor_token(':');
8820                 goto end_of_asm;
8821         }
8822
8823         asm_statement->outputs = parse_asm_arguments(true);
8824         if (!next_if(':')) {
8825                 rem_anchor_token(':');
8826                 goto end_of_asm;
8827         }
8828
8829         asm_statement->inputs = parse_asm_arguments(false);
8830         if (!next_if(':')) {
8831                 rem_anchor_token(':');
8832                 goto end_of_asm;
8833         }
8834         rem_anchor_token(':');
8835
8836         asm_statement->clobbers = parse_asm_clobbers();
8837
8838 end_of_asm:
8839         rem_anchor_token(')');
8840         expect(')');
8841         expect(';');
8842
8843         if (asm_statement->outputs == NULL) {
8844                 /* GCC: An 'asm' instruction without any output operands will be treated
8845                  * identically to a volatile 'asm' instruction. */
8846                 asm_statement->is_volatile = true;
8847         }
8848
8849         return statement;
8850 }
8851
8852 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8853 {
8854         statement_t *inner_stmt;
8855         switch (token.kind) {
8856                 case '}':
8857                         errorf(&label->base.source_position, "%s at end of compound statement", label_kind);
8858                         inner_stmt = create_error_statement();
8859                         break;
8860
8861                 case ';':
8862                         if (label->kind == STATEMENT_LABEL) {
8863                                 /* Eat an empty statement here, to avoid the warning about an empty
8864                                  * statement after a label.  label:; is commonly used to have a label
8865                                  * before a closing brace. */
8866                                 inner_stmt = create_empty_statement();
8867                                 next_token();
8868                                 break;
8869                         }
8870                         /* FALLTHROUGH */
8871
8872                 default:
8873                         inner_stmt = parse_statement();
8874                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8875                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8876                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8877                                 errorf(&inner_stmt->base.source_position, "declaration after %s", label_kind);
8878                         }
8879                         break;
8880         }
8881         return inner_stmt;
8882 }
8883
8884 /**
8885  * Parse a case statement.
8886  */
8887 static statement_t *parse_case_statement(void)
8888 {
8889         statement_t       *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8890         source_position_t *const pos       = &statement->base.source_position;
8891
8892         eat(T_case);
8893         add_anchor_token(':');
8894
8895         expression_t *expression = parse_expression();
8896         type_t *expression_type = expression->base.type;
8897         type_t *skipped         = skip_typeref(expression_type);
8898         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8899                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8900                        expression, expression_type);
8901         }
8902
8903         type_t *type = expression_type;
8904         if (current_switch != NULL) {
8905                 type_t *switch_type = current_switch->expression->base.type;
8906                 if (is_type_valid(switch_type)) {
8907                         expression = create_implicit_cast(expression, switch_type);
8908                 }
8909         }
8910
8911         statement->case_label.expression = expression;
8912         expression_classification_t const expr_class = is_constant_expression(expression);
8913         if (expr_class != EXPR_CLASS_CONSTANT) {
8914                 if (expr_class != EXPR_CLASS_ERROR) {
8915                         errorf(pos, "case label does not reduce to an integer constant");
8916                 }
8917                 statement->case_label.is_bad = true;
8918         } else {
8919                 long const val = fold_constant_to_int(expression);
8920                 statement->case_label.first_case = val;
8921                 statement->case_label.last_case  = val;
8922         }
8923
8924         if (GNU_MODE) {
8925                 if (next_if(T_DOTDOTDOT)) {
8926                         expression_t *end_range = parse_expression();
8927                         expression_type = expression->base.type;
8928                         skipped         = skip_typeref(expression_type);
8929                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8930                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8931                                            expression, expression_type);
8932                         }
8933
8934                         end_range = create_implicit_cast(end_range, type);
8935                         statement->case_label.end_range = end_range;
8936                         expression_classification_t const end_class = is_constant_expression(end_range);
8937                         if (end_class != EXPR_CLASS_CONSTANT) {
8938                                 if (end_class != EXPR_CLASS_ERROR) {
8939                                         errorf(pos, "case range does not reduce to an integer constant");
8940                                 }
8941                                 statement->case_label.is_bad = true;
8942                         } else {
8943                                 long const val = fold_constant_to_int(end_range);
8944                                 statement->case_label.last_case = val;
8945
8946                                 if (val < statement->case_label.first_case) {
8947                                         statement->case_label.is_empty_range = true;
8948                                         warningf(WARN_OTHER, pos, "empty range specified");
8949                                 }
8950                         }
8951                 }
8952         }
8953
8954         PUSH_PARENT(statement);
8955
8956         rem_anchor_token(':');
8957         expect(':');
8958
8959         if (current_switch != NULL) {
8960                 if (! statement->case_label.is_bad) {
8961                         /* Check for duplicate case values */
8962                         case_label_statement_t *c = &statement->case_label;
8963                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8964                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8965                                         continue;
8966
8967                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8968                                         continue;
8969
8970                                 errorf(pos, "duplicate case value (previously used %P)",
8971                                        &l->base.source_position);
8972                                 break;
8973                         }
8974                 }
8975                 /* link all cases into the switch statement */
8976                 if (current_switch->last_case == NULL) {
8977                         current_switch->first_case      = &statement->case_label;
8978                 } else {
8979                         current_switch->last_case->next = &statement->case_label;
8980                 }
8981                 current_switch->last_case = &statement->case_label;
8982         } else {
8983                 errorf(pos, "case label not within a switch statement");
8984         }
8985
8986         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8987
8988         POP_PARENT();
8989         return statement;
8990 }
8991
8992 /**
8993  * Parse a default statement.
8994  */
8995 static statement_t *parse_default_statement(void)
8996 {
8997         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8998
8999         eat(T_default);
9000
9001         PUSH_PARENT(statement);
9002
9003         expect(':');
9004
9005         if (current_switch != NULL) {
9006                 const case_label_statement_t *def_label = current_switch->default_label;
9007                 if (def_label != NULL) {
9008                         errorf(&statement->base.source_position, "multiple default labels in one switch (previous declared %P)", &def_label->base.source_position);
9009                 } else {
9010                         current_switch->default_label = &statement->case_label;
9011
9012                         /* link all cases into the switch statement */
9013                         if (current_switch->last_case == NULL) {
9014                                 current_switch->first_case      = &statement->case_label;
9015                         } else {
9016                                 current_switch->last_case->next = &statement->case_label;
9017                         }
9018                         current_switch->last_case = &statement->case_label;
9019                 }
9020         } else {
9021                 errorf(&statement->base.source_position,
9022                         "'default' label not within a switch statement");
9023         }
9024
9025         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
9026
9027         POP_PARENT();
9028         return statement;
9029 }
9030
9031 /**
9032  * Parse a label statement.
9033  */
9034 static statement_t *parse_label_statement(void)
9035 {
9036         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9037         label_t     *const label     = get_label();
9038         statement->label.label = label;
9039
9040         PUSH_PARENT(statement);
9041
9042         /* if statement is already set then the label is defined twice,
9043          * otherwise it was just mentioned in a goto/local label declaration so far
9044          */
9045         source_position_t const* const pos = &statement->base.source_position;
9046         if (label->statement != NULL) {
9047                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.source_position);
9048         } else {
9049                 label->base.source_position = *pos;
9050                 label->statement            = statement;
9051         }
9052
9053         eat(':');
9054
9055         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9056                 parse_attributes(NULL); // TODO process attributes
9057         }
9058
9059         statement->label.statement = parse_label_inner_statement(statement, "label");
9060
9061         /* remember the labels in a list for later checking */
9062         *label_anchor = &statement->label;
9063         label_anchor  = &statement->label.next;
9064
9065         POP_PARENT();
9066         return statement;
9067 }
9068
9069 static statement_t *parse_inner_statement(void)
9070 {
9071         statement_t *const stmt = parse_statement();
9072         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9073         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9074         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9075                 errorf(&stmt->base.source_position, "declaration as inner statement, use {}");
9076         }
9077         return stmt;
9078 }
9079
9080 /**
9081  * Parse an expression in parentheses and mark its variables as read.
9082  */
9083 static expression_t *parse_condition(void)
9084 {
9085         expect('(');
9086         add_anchor_token(')');
9087         expression_t *const expr = parse_expression();
9088         mark_vars_read(expr, NULL);
9089         rem_anchor_token(')');
9090         expect(')');
9091         return expr;
9092 }
9093
9094 /**
9095  * Parse an if statement.
9096  */
9097 static statement_t *parse_if(void)
9098 {
9099         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9100
9101         eat(T_if);
9102
9103         PUSH_PARENT(statement);
9104         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9105
9106         add_anchor_token(T_else);
9107
9108         expression_t *const expr = parse_condition();
9109         statement->ifs.condition = expr;
9110         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9111          *             scalar type. */
9112         semantic_condition(expr, "condition of 'if'-statment");
9113
9114         statement_t *const true_stmt = parse_inner_statement();
9115         statement->ifs.true_statement = true_stmt;
9116         rem_anchor_token(T_else);
9117
9118         if (true_stmt->kind == STATEMENT_EMPTY) {
9119                 warningf(WARN_EMPTY_BODY, HERE,
9120                         "suggest braces around empty body in an ‘if’ statement");
9121         }
9122
9123         if (next_if(T_else)) {
9124                 statement->ifs.false_statement = parse_inner_statement();
9125
9126                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9127                         warningf(WARN_EMPTY_BODY, HERE,
9128                                         "suggest braces around empty body in an ‘if’ statement");
9129                 }
9130         } else if (true_stmt->kind == STATEMENT_IF &&
9131                         true_stmt->ifs.false_statement != NULL) {
9132                 source_position_t const *const pos = &true_stmt->base.source_position;
9133                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9134         }
9135
9136         POP_SCOPE();
9137         POP_PARENT();
9138         return statement;
9139 }
9140
9141 /**
9142  * Check that all enums are handled in a switch.
9143  *
9144  * @param statement  the switch statement to check
9145  */
9146 static void check_enum_cases(const switch_statement_t *statement)
9147 {
9148         if (!is_warn_on(WARN_SWITCH_ENUM))
9149                 return;
9150         const type_t *type = skip_typeref(statement->expression->base.type);
9151         if (! is_type_enum(type))
9152                 return;
9153         const enum_type_t *enumt = &type->enumt;
9154
9155         /* if we have a default, no warnings */
9156         if (statement->default_label != NULL)
9157                 return;
9158
9159         /* FIXME: calculation of value should be done while parsing */
9160         /* TODO: quadratic algorithm here. Change to an n log n one */
9161         long            last_value = -1;
9162         const entity_t *entry      = enumt->enume->base.next;
9163         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9164              entry = entry->base.next) {
9165                 const expression_t *expression = entry->enum_value.value;
9166                 long                value      = expression != NULL ? fold_constant_to_int(expression) : last_value + 1;
9167                 bool                found      = false;
9168                 for (const case_label_statement_t *l = statement->first_case; l != NULL; l = l->next) {
9169                         if (l->expression == NULL)
9170                                 continue;
9171                         if (l->first_case <= value && value <= l->last_case) {
9172                                 found = true;
9173                                 break;
9174                         }
9175                 }
9176                 if (!found) {
9177                         source_position_t const *const pos = &statement->base.source_position;
9178                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9179                 }
9180                 last_value = value;
9181         }
9182 }
9183
9184 /**
9185  * Parse a switch statement.
9186  */
9187 static statement_t *parse_switch(void)
9188 {
9189         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9190
9191         eat(T_switch);
9192
9193         PUSH_PARENT(statement);
9194         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9195
9196         expression_t *const expr = parse_condition();
9197         type_t       *      type = skip_typeref(expr->base.type);
9198         if (is_type_integer(type)) {
9199                 type = promote_integer(type);
9200                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9201                         warningf(WARN_TRADITIONAL, &expr->base.source_position, "'%T' switch expression not converted to '%T' in ISO C", type, type_int);
9202                 }
9203         } else if (is_type_valid(type)) {
9204                 errorf(&expr->base.source_position,
9205                        "switch quantity is not an integer, but '%T'", type);
9206                 type = type_error_type;
9207         }
9208         statement->switchs.expression = create_implicit_cast(expr, type);
9209
9210         switch_statement_t *rem = current_switch;
9211         current_switch          = &statement->switchs;
9212         statement->switchs.body = parse_inner_statement();
9213         current_switch          = rem;
9214
9215         if (statement->switchs.default_label == NULL) {
9216                 warningf(WARN_SWITCH_DEFAULT, &statement->base.source_position, "switch has no default case");
9217         }
9218         check_enum_cases(&statement->switchs);
9219
9220         POP_SCOPE();
9221         POP_PARENT();
9222         return statement;
9223 }
9224
9225 static statement_t *parse_loop_body(statement_t *const loop)
9226 {
9227         statement_t *const rem = current_loop;
9228         current_loop = loop;
9229
9230         statement_t *const body = parse_inner_statement();
9231
9232         current_loop = rem;
9233         return body;
9234 }
9235
9236 /**
9237  * Parse a while statement.
9238  */
9239 static statement_t *parse_while(void)
9240 {
9241         statement_t *statement = allocate_statement_zero(STATEMENT_WHILE);
9242
9243         eat(T_while);
9244
9245         PUSH_PARENT(statement);
9246         PUSH_SCOPE_STATEMENT(&statement->whiles.scope);
9247
9248         expression_t *const cond = parse_condition();
9249         statement->whiles.condition = cond;
9250         /* §6.8.5:2    The controlling expression of an iteration statement shall
9251          *             have scalar type. */
9252         semantic_condition(cond, "condition of 'while'-statement");
9253
9254         statement->whiles.body = parse_loop_body(statement);
9255
9256         POP_SCOPE();
9257         POP_PARENT();
9258         return statement;
9259 }
9260
9261 /**
9262  * Parse a do statement.
9263  */
9264 static statement_t *parse_do(void)
9265 {
9266         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9267
9268         eat(T_do);
9269
9270         PUSH_PARENT(statement);
9271         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9272
9273         add_anchor_token(T_while);
9274         statement->do_while.body = parse_loop_body(statement);
9275         rem_anchor_token(T_while);
9276
9277         expect(T_while);
9278         expression_t *const cond = parse_condition();
9279         statement->do_while.condition = cond;
9280         /* §6.8.5:2    The controlling expression of an iteration statement shall
9281          *             have scalar type. */
9282         semantic_condition(cond, "condition of 'do-while'-statement");
9283         expect(';');
9284
9285         POP_SCOPE();
9286         POP_PARENT();
9287         return statement;
9288 }
9289
9290 /**
9291  * Parse a for statement.
9292  */
9293 static statement_t *parse_for(void)
9294 {
9295         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9296
9297         eat(T_for);
9298
9299         PUSH_PARENT(statement);
9300         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9301
9302         expect('(');
9303         add_anchor_token(')');
9304
9305         PUSH_EXTENSION();
9306
9307         if (next_if(';')) {
9308         } else if (is_declaration_specifier(&token)) {
9309                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9310         } else {
9311                 add_anchor_token(';');
9312                 expression_t *const init = parse_expression();
9313                 statement->fors.initialisation = init;
9314                 mark_vars_read(init, ENT_ANY);
9315                 if (!expression_has_effect(init)) {
9316                         warningf(WARN_UNUSED_VALUE, &init->base.source_position, "initialisation of 'for'-statement has no effect");
9317                 }
9318                 rem_anchor_token(';');
9319                 expect(';');
9320         }
9321
9322         POP_EXTENSION();
9323
9324         if (token.kind != ';') {
9325                 add_anchor_token(';');
9326                 expression_t *const cond = parse_expression();
9327                 statement->fors.condition = cond;
9328                 /* §6.8.5:2    The controlling expression of an iteration statement
9329                  *             shall have scalar type. */
9330                 semantic_condition(cond, "condition of 'for'-statement");
9331                 mark_vars_read(cond, NULL);
9332                 rem_anchor_token(';');
9333         }
9334         expect(';');
9335         if (token.kind != ')') {
9336                 expression_t *const step = parse_expression();
9337                 statement->fors.step = step;
9338                 mark_vars_read(step, ENT_ANY);
9339                 if (!expression_has_effect(step)) {
9340                         warningf(WARN_UNUSED_VALUE, &step->base.source_position, "step of 'for'-statement has no effect");
9341                 }
9342         }
9343         rem_anchor_token(')');
9344         expect(')');
9345         statement->fors.body = parse_loop_body(statement);
9346
9347         POP_SCOPE();
9348         POP_PARENT();
9349         return statement;
9350 }
9351
9352 /**
9353  * Parse a goto statement.
9354  */
9355 static statement_t *parse_goto(void)
9356 {
9357         statement_t *statement;
9358         if (GNU_MODE && look_ahead(1)->kind == '*') {
9359                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9360                 eat(T_goto);
9361                 eat('*');
9362
9363                 expression_t *expression = parse_expression();
9364                 mark_vars_read(expression, NULL);
9365
9366                 /* Argh: although documentation says the expression must be of type void*,
9367                  * gcc accepts anything that can be casted into void* without error */
9368                 type_t *type = expression->base.type;
9369
9370                 if (type != type_error_type) {
9371                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9372                                 errorf(&expression->base.source_position,
9373                                         "cannot convert to a pointer type");
9374                         } else if (type != type_void_ptr) {
9375                                 warningf(WARN_OTHER, &expression->base.source_position, "type of computed goto expression should be 'void*' not '%T'", type);
9376                         }
9377                         expression = create_implicit_cast(expression, type_void_ptr);
9378                 }
9379
9380                 statement->computed_goto.expression = expression;
9381         } else {
9382                 statement = allocate_statement_zero(STATEMENT_GOTO);
9383                 eat(T_goto);
9384                 if (token.kind == T_IDENTIFIER) {
9385                         label_t *const label = get_label();
9386                         label->used            = true;
9387                         statement->gotos.label = label;
9388
9389                         /* remember the goto's in a list for later checking */
9390                         *goto_anchor = &statement->gotos;
9391                         goto_anchor  = &statement->gotos.next;
9392                 } else {
9393                         if (GNU_MODE)
9394                                 parse_error_expected("while parsing goto", T_IDENTIFIER, '*', NULL);
9395                         else
9396                                 parse_error_expected("while parsing goto", T_IDENTIFIER, NULL);
9397                         eat_until_anchor();
9398                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_source_position)->label;
9399                 }
9400         }
9401
9402         expect(';');
9403         return statement;
9404 }
9405
9406 /**
9407  * Parse a continue statement.
9408  */
9409 static statement_t *parse_continue(void)
9410 {
9411         if (current_loop == NULL) {
9412                 errorf(HERE, "continue statement not within loop");
9413         }
9414
9415         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9416
9417         eat(T_continue);
9418         expect(';');
9419         return statement;
9420 }
9421
9422 /**
9423  * Parse a break statement.
9424  */
9425 static statement_t *parse_break(void)
9426 {
9427         if (current_switch == NULL && current_loop == NULL) {
9428                 errorf(HERE, "break statement not within loop or switch");
9429         }
9430
9431         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9432
9433         eat(T_break);
9434         expect(';');
9435         return statement;
9436 }
9437
9438 /**
9439  * Parse a __leave statement.
9440  */
9441 static statement_t *parse_leave_statement(void)
9442 {
9443         if (current_try == NULL) {
9444                 errorf(HERE, "__leave statement not within __try");
9445         }
9446
9447         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9448
9449         eat(T___leave);
9450         expect(';');
9451         return statement;
9452 }
9453
9454 /**
9455  * Check if a given entity represents a local variable.
9456  */
9457 static bool is_local_variable(const entity_t *entity)
9458 {
9459         if (entity->kind != ENTITY_VARIABLE)
9460                 return false;
9461
9462         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9463         case STORAGE_CLASS_AUTO:
9464         case STORAGE_CLASS_REGISTER: {
9465                 const type_t *type = skip_typeref(entity->declaration.type);
9466                 if (is_type_function(type)) {
9467                         return false;
9468                 } else {
9469                         return true;
9470                 }
9471         }
9472         default:
9473                 return false;
9474         }
9475 }
9476
9477 /**
9478  * Check if a given expression represents a local variable.
9479  */
9480 static bool expression_is_local_variable(const expression_t *expression)
9481 {
9482         if (expression->base.kind != EXPR_REFERENCE) {
9483                 return false;
9484         }
9485         const entity_t *entity = expression->reference.entity;
9486         return is_local_variable(entity);
9487 }
9488
9489 /**
9490  * Check if a given expression represents a local variable and
9491  * return its declaration then, else return NULL.
9492  */
9493 entity_t *expression_is_variable(const expression_t *expression)
9494 {
9495         if (expression->base.kind != EXPR_REFERENCE) {
9496                 return NULL;
9497         }
9498         entity_t *entity = expression->reference.entity;
9499         if (entity->kind != ENTITY_VARIABLE)
9500                 return NULL;
9501
9502         return entity;
9503 }
9504
9505 static void err_or_warn(source_position_t const *const pos, char const *const msg)
9506 {
9507         if (c_mode & _CXX || strict_mode) {
9508                 errorf(pos, msg);
9509         } else {
9510                 warningf(WARN_OTHER, pos, msg);
9511         }
9512 }
9513
9514 /**
9515  * Parse a return statement.
9516  */
9517 static statement_t *parse_return(void)
9518 {
9519         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9520         eat(T_return);
9521
9522         expression_t *return_value = NULL;
9523         if (token.kind != ';') {
9524                 return_value = parse_expression();
9525                 mark_vars_read(return_value, NULL);
9526         }
9527
9528         const type_t *const func_type = skip_typeref(current_function->base.type);
9529         assert(is_type_function(func_type));
9530         type_t *const return_type = skip_typeref(func_type->function.return_type);
9531
9532         source_position_t const *const pos = &statement->base.source_position;
9533         if (return_value != NULL) {
9534                 type_t *return_value_type = skip_typeref(return_value->base.type);
9535
9536                 if (is_type_void(return_type)) {
9537                         if (!is_type_void(return_value_type)) {
9538                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9539                                 /* Only warn in C mode, because GCC does the same */
9540                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9541                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9542                                 /* Only warn in C mode, because GCC does the same */
9543                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9544                         }
9545                 } else {
9546                         assign_error_t error = semantic_assign(return_type, return_value);
9547                         report_assign_error(error, return_type, return_value, "'return'",
9548                                             pos);
9549                 }
9550                 return_value = create_implicit_cast(return_value, return_type);
9551                 /* check for returning address of a local var */
9552                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9553                         const expression_t *expression = return_value->unary.value;
9554                         if (expression_is_local_variable(expression)) {
9555                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9556                         }
9557                 }
9558         } else if (!is_type_void(return_type)) {
9559                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9560                 err_or_warn(pos, "'return' without value, in function returning non-void");
9561         }
9562         statement->returns.value = return_value;
9563
9564         expect(';');
9565         return statement;
9566 }
9567
9568 /**
9569  * Parse a declaration statement.
9570  */
9571 static statement_t *parse_declaration_statement(void)
9572 {
9573         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9574
9575         entity_t *before = current_scope->last_entity;
9576         if (GNU_MODE) {
9577                 parse_external_declaration();
9578         } else {
9579                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9580         }
9581
9582         declaration_statement_t *const decl  = &statement->declaration;
9583         entity_t                *const begin =
9584                 before != NULL ? before->base.next : current_scope->entities;
9585         decl->declarations_begin = begin;
9586         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9587
9588         return statement;
9589 }
9590
9591 /**
9592  * Parse an expression statement, ie. expr ';'.
9593  */
9594 static statement_t *parse_expression_statement(void)
9595 {
9596         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9597
9598         expression_t *const expr         = parse_expression();
9599         statement->expression.expression = expr;
9600         mark_vars_read(expr, ENT_ANY);
9601
9602         expect(';');
9603         return statement;
9604 }
9605
9606 /**
9607  * Parse a microsoft __try { } __finally { } or
9608  * __try{ } __except() { }
9609  */
9610 static statement_t *parse_ms_try_statment(void)
9611 {
9612         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9613         eat(T___try);
9614
9615         PUSH_PARENT(statement);
9616
9617         ms_try_statement_t *rem = current_try;
9618         current_try = &statement->ms_try;
9619         statement->ms_try.try_statement = parse_compound_statement(false);
9620         current_try = rem;
9621
9622         POP_PARENT();
9623
9624         if (next_if(T___except)) {
9625                 expression_t *const expr = parse_condition();
9626                 type_t       *      type = skip_typeref(expr->base.type);
9627                 if (is_type_integer(type)) {
9628                         type = promote_integer(type);
9629                 } else if (is_type_valid(type)) {
9630                         errorf(&expr->base.source_position,
9631                                "__expect expression is not an integer, but '%T'", type);
9632                         type = type_error_type;
9633                 }
9634                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9635         } else if (!next_if(T__finally)) {
9636                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9637         }
9638         statement->ms_try.final_statement = parse_compound_statement(false);
9639         return statement;
9640 }
9641
9642 static statement_t *parse_empty_statement(void)
9643 {
9644         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9645         statement_t *const statement = create_empty_statement();
9646         eat(';');
9647         return statement;
9648 }
9649
9650 static statement_t *parse_local_label_declaration(void)
9651 {
9652         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9653
9654         eat(T___label__);
9655
9656         entity_t *begin   = NULL;
9657         entity_t *end     = NULL;
9658         entity_t **anchor = &begin;
9659         do {
9660                 source_position_t pos;
9661                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9662                 if (!symbol)
9663                         goto end_error;
9664
9665                 entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9666                 if (entity != NULL && entity->base.parent_scope == current_scope) {
9667                         source_position_t const *const ppos = &entity->base.source_position;
9668                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9669                 } else {
9670                         entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9671                         entity->base.parent_scope = current_scope;
9672
9673                         *anchor = entity;
9674                         anchor  = &entity->base.next;
9675                         end     = entity;
9676
9677                         environment_push(entity);
9678                 }
9679         } while (next_if(','));
9680         expect(';');
9681 end_error:
9682         statement->declaration.declarations_begin = begin;
9683         statement->declaration.declarations_end   = end;
9684         return statement;
9685 }
9686
9687 static void parse_namespace_definition(void)
9688 {
9689         eat(T_namespace);
9690
9691         entity_t *entity = NULL;
9692         symbol_t *symbol = NULL;
9693
9694         if (token.kind == T_IDENTIFIER) {
9695                 symbol = token.base.symbol;
9696                 next_token();
9697
9698                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9699                 if (entity != NULL
9700                                 && entity->kind != ENTITY_NAMESPACE
9701                                 && entity->base.parent_scope == current_scope) {
9702                         if (is_entity_valid(entity)) {
9703                                 error_redefined_as_different_kind(&token.base.source_position,
9704                                                 entity, ENTITY_NAMESPACE);
9705                         }
9706                         entity = NULL;
9707                 }
9708         }
9709
9710         if (entity == NULL) {
9711                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9712                 entity->base.parent_scope = current_scope;
9713         }
9714
9715         if (token.kind == '=') {
9716                 /* TODO: parse namespace alias */
9717                 panic("namespace alias definition not supported yet");
9718         }
9719
9720         environment_push(entity);
9721         append_entity(current_scope, entity);
9722
9723         PUSH_SCOPE(&entity->namespacee.members);
9724         PUSH_CURRENT_ENTITY(entity);
9725
9726         add_anchor_token('}');
9727         expect('{');
9728         parse_externals();
9729         rem_anchor_token('}');
9730         expect('}');
9731
9732         POP_CURRENT_ENTITY();
9733         POP_SCOPE();
9734 }
9735
9736 /**
9737  * Parse a statement.
9738  * There's also parse_statement() which additionally checks for
9739  * "statement has no effect" warnings
9740  */
9741 static statement_t *intern_parse_statement(void)
9742 {
9743         /* declaration or statement */
9744         statement_t *statement;
9745         switch (token.kind) {
9746         case T_IDENTIFIER: {
9747                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9748                 if (la1_type == ':') {
9749                         statement = parse_label_statement();
9750                 } else if (is_typedef_symbol(token.base.symbol)) {
9751                         statement = parse_declaration_statement();
9752                 } else {
9753                         /* it's an identifier, the grammar says this must be an
9754                          * expression statement. However it is common that users mistype
9755                          * declaration types, so we guess a bit here to improve robustness
9756                          * for incorrect programs */
9757                         switch (la1_type) {
9758                         case '&':
9759                         case '*':
9760                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9761                         default:
9762                                         statement = parse_expression_statement();
9763                                 } else {
9764                         DECLARATION_START
9765                         case T_IDENTIFIER:
9766                                         statement = parse_declaration_statement();
9767                                 }
9768                                 break;
9769                         }
9770                 }
9771                 break;
9772         }
9773
9774         case T___extension__: {
9775                 /* This can be a prefix to a declaration or an expression statement.
9776                  * We simply eat it now and parse the rest with tail recursion. */
9777                 PUSH_EXTENSION();
9778                 statement = intern_parse_statement();
9779                 POP_EXTENSION();
9780                 break;
9781         }
9782
9783         DECLARATION_START
9784                 statement = parse_declaration_statement();
9785                 break;
9786
9787         case T___label__:
9788                 statement = parse_local_label_declaration();
9789                 break;
9790
9791         case ';':         statement = parse_empty_statement();         break;
9792         case '{':         statement = parse_compound_statement(false); break;
9793         case T___leave:   statement = parse_leave_statement();         break;
9794         case T___try:     statement = parse_ms_try_statment();         break;
9795         case T_asm:       statement = parse_asm_statement();           break;
9796         case T_break:     statement = parse_break();                   break;
9797         case T_case:      statement = parse_case_statement();          break;
9798         case T_continue:  statement = parse_continue();                break;
9799         case T_default:   statement = parse_default_statement();       break;
9800         case T_do:        statement = parse_do();                      break;
9801         case T_for:       statement = parse_for();                     break;
9802         case T_goto:      statement = parse_goto();                    break;
9803         case T_if:        statement = parse_if();                      break;
9804         case T_return:    statement = parse_return();                  break;
9805         case T_switch:    statement = parse_switch();                  break;
9806         case T_while:     statement = parse_while();                   break;
9807
9808         EXPRESSION_START
9809                 statement = parse_expression_statement();
9810                 break;
9811
9812         default:
9813                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9814                 statement = create_error_statement();
9815                 eat_until_anchor();
9816                 break;
9817         }
9818
9819         return statement;
9820 }
9821
9822 /**
9823  * parse a statement and emits "statement has no effect" warning if needed
9824  * (This is really a wrapper around intern_parse_statement with check for 1
9825  *  single warning. It is needed, because for statement expressions we have
9826  *  to avoid the warning on the last statement)
9827  */
9828 static statement_t *parse_statement(void)
9829 {
9830         statement_t *statement = intern_parse_statement();
9831
9832         if (statement->kind == STATEMENT_EXPRESSION) {
9833                 expression_t *expression = statement->expression.expression;
9834                 if (!expression_has_effect(expression)) {
9835                         warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9836                 }
9837         }
9838
9839         return statement;
9840 }
9841
9842 /**
9843  * Parse a compound statement.
9844  */
9845 static statement_t *parse_compound_statement(bool inside_expression_statement)
9846 {
9847         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9848
9849         PUSH_PARENT(statement);
9850         PUSH_SCOPE(&statement->compound.scope);
9851
9852         eat('{');
9853         add_anchor_token('}');
9854         /* tokens, which can start a statement */
9855         /* TODO MS, __builtin_FOO */
9856         add_anchor_token('!');
9857         add_anchor_token('&');
9858         add_anchor_token('(');
9859         add_anchor_token('*');
9860         add_anchor_token('+');
9861         add_anchor_token('-');
9862         add_anchor_token(';');
9863         add_anchor_token('{');
9864         add_anchor_token('~');
9865         add_anchor_token(T_CHARACTER_CONSTANT);
9866         add_anchor_token(T_COLONCOLON);
9867         add_anchor_token(T_FLOATINGPOINT);
9868         add_anchor_token(T_IDENTIFIER);
9869         add_anchor_token(T_INTEGER);
9870         add_anchor_token(T_MINUSMINUS);
9871         add_anchor_token(T_PLUSPLUS);
9872         add_anchor_token(T_STRING_LITERAL);
9873         add_anchor_token(T_WIDE_CHARACTER_CONSTANT);
9874         add_anchor_token(T_WIDE_STRING_LITERAL);
9875         add_anchor_token(T__Bool);
9876         add_anchor_token(T__Complex);
9877         add_anchor_token(T__Imaginary);
9878         add_anchor_token(T___FUNCTION__);
9879         add_anchor_token(T___PRETTY_FUNCTION__);
9880         add_anchor_token(T___alignof__);
9881         add_anchor_token(T___attribute__);
9882         add_anchor_token(T___builtin_va_start);
9883         add_anchor_token(T___extension__);
9884         add_anchor_token(T___func__);
9885         add_anchor_token(T___imag__);
9886         add_anchor_token(T___label__);
9887         add_anchor_token(T___real__);
9888         add_anchor_token(T___thread);
9889         add_anchor_token(T_asm);
9890         add_anchor_token(T_auto);
9891         add_anchor_token(T_bool);
9892         add_anchor_token(T_break);
9893         add_anchor_token(T_case);
9894         add_anchor_token(T_char);
9895         add_anchor_token(T_class);
9896         add_anchor_token(T_const);
9897         add_anchor_token(T_const_cast);
9898         add_anchor_token(T_continue);
9899         add_anchor_token(T_default);
9900         add_anchor_token(T_delete);
9901         add_anchor_token(T_double);
9902         add_anchor_token(T_do);
9903         add_anchor_token(T_dynamic_cast);
9904         add_anchor_token(T_enum);
9905         add_anchor_token(T_extern);
9906         add_anchor_token(T_false);
9907         add_anchor_token(T_float);
9908         add_anchor_token(T_for);
9909         add_anchor_token(T_goto);
9910         add_anchor_token(T_if);
9911         add_anchor_token(T_inline);
9912         add_anchor_token(T_int);
9913         add_anchor_token(T_long);
9914         add_anchor_token(T_new);
9915         add_anchor_token(T_operator);
9916         add_anchor_token(T_register);
9917         add_anchor_token(T_reinterpret_cast);
9918         add_anchor_token(T_restrict);
9919         add_anchor_token(T_return);
9920         add_anchor_token(T_short);
9921         add_anchor_token(T_signed);
9922         add_anchor_token(T_sizeof);
9923         add_anchor_token(T_static);
9924         add_anchor_token(T_static_cast);
9925         add_anchor_token(T_struct);
9926         add_anchor_token(T_switch);
9927         add_anchor_token(T_template);
9928         add_anchor_token(T_this);
9929         add_anchor_token(T_throw);
9930         add_anchor_token(T_true);
9931         add_anchor_token(T_try);
9932         add_anchor_token(T_typedef);
9933         add_anchor_token(T_typeid);
9934         add_anchor_token(T_typename);
9935         add_anchor_token(T_typeof);
9936         add_anchor_token(T_union);
9937         add_anchor_token(T_unsigned);
9938         add_anchor_token(T_using);
9939         add_anchor_token(T_void);
9940         add_anchor_token(T_volatile);
9941         add_anchor_token(T_wchar_t);
9942         add_anchor_token(T_while);
9943
9944         statement_t **anchor            = &statement->compound.statements;
9945         bool          only_decls_so_far = true;
9946         while (token.kind != '}' && token.kind != T_EOF) {
9947                 statement_t *sub_statement = intern_parse_statement();
9948                 if (sub_statement->kind == STATEMENT_ERROR) {
9949                         break;
9950                 }
9951
9952                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9953                         only_decls_so_far = false;
9954                 } else if (!only_decls_so_far) {
9955                         source_position_t const *const pos = &sub_statement->base.source_position;
9956                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9957                 }
9958
9959                 *anchor = sub_statement;
9960                 anchor  = &sub_statement->base.next;
9961         }
9962         expect('}');
9963
9964         /* look over all statements again to produce no effect warnings */
9965         if (is_warn_on(WARN_UNUSED_VALUE)) {
9966                 statement_t *sub_statement = statement->compound.statements;
9967                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9968                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9969                                 continue;
9970                         /* don't emit a warning for the last expression in an expression
9971                          * statement as it has always an effect */
9972                         if (inside_expression_statement && sub_statement->base.next == NULL)
9973                                 continue;
9974
9975                         expression_t *expression = sub_statement->expression.expression;
9976                         if (!expression_has_effect(expression)) {
9977                                 warningf(WARN_UNUSED_VALUE, &expression->base.source_position, "statement has no effect");
9978                         }
9979                 }
9980         }
9981
9982         rem_anchor_token(T_while);
9983         rem_anchor_token(T_wchar_t);
9984         rem_anchor_token(T_volatile);
9985         rem_anchor_token(T_void);
9986         rem_anchor_token(T_using);
9987         rem_anchor_token(T_unsigned);
9988         rem_anchor_token(T_union);
9989         rem_anchor_token(T_typeof);
9990         rem_anchor_token(T_typename);
9991         rem_anchor_token(T_typeid);
9992         rem_anchor_token(T_typedef);
9993         rem_anchor_token(T_try);
9994         rem_anchor_token(T_true);
9995         rem_anchor_token(T_throw);
9996         rem_anchor_token(T_this);
9997         rem_anchor_token(T_template);
9998         rem_anchor_token(T_switch);
9999         rem_anchor_token(T_struct);
10000         rem_anchor_token(T_static_cast);
10001         rem_anchor_token(T_static);
10002         rem_anchor_token(T_sizeof);
10003         rem_anchor_token(T_signed);
10004         rem_anchor_token(T_short);
10005         rem_anchor_token(T_return);
10006         rem_anchor_token(T_restrict);
10007         rem_anchor_token(T_reinterpret_cast);
10008         rem_anchor_token(T_register);
10009         rem_anchor_token(T_operator);
10010         rem_anchor_token(T_new);
10011         rem_anchor_token(T_long);
10012         rem_anchor_token(T_int);
10013         rem_anchor_token(T_inline);
10014         rem_anchor_token(T_if);
10015         rem_anchor_token(T_goto);
10016         rem_anchor_token(T_for);
10017         rem_anchor_token(T_float);
10018         rem_anchor_token(T_false);
10019         rem_anchor_token(T_extern);
10020         rem_anchor_token(T_enum);
10021         rem_anchor_token(T_dynamic_cast);
10022         rem_anchor_token(T_do);
10023         rem_anchor_token(T_double);
10024         rem_anchor_token(T_delete);
10025         rem_anchor_token(T_default);
10026         rem_anchor_token(T_continue);
10027         rem_anchor_token(T_const_cast);
10028         rem_anchor_token(T_const);
10029         rem_anchor_token(T_class);
10030         rem_anchor_token(T_char);
10031         rem_anchor_token(T_case);
10032         rem_anchor_token(T_break);
10033         rem_anchor_token(T_bool);
10034         rem_anchor_token(T_auto);
10035         rem_anchor_token(T_asm);
10036         rem_anchor_token(T___thread);
10037         rem_anchor_token(T___real__);
10038         rem_anchor_token(T___label__);
10039         rem_anchor_token(T___imag__);
10040         rem_anchor_token(T___func__);
10041         rem_anchor_token(T___extension__);
10042         rem_anchor_token(T___builtin_va_start);
10043         rem_anchor_token(T___attribute__);
10044         rem_anchor_token(T___alignof__);
10045         rem_anchor_token(T___PRETTY_FUNCTION__);
10046         rem_anchor_token(T___FUNCTION__);
10047         rem_anchor_token(T__Imaginary);
10048         rem_anchor_token(T__Complex);
10049         rem_anchor_token(T__Bool);
10050         rem_anchor_token(T_WIDE_STRING_LITERAL);
10051         rem_anchor_token(T_WIDE_CHARACTER_CONSTANT);
10052         rem_anchor_token(T_STRING_LITERAL);
10053         rem_anchor_token(T_PLUSPLUS);
10054         rem_anchor_token(T_MINUSMINUS);
10055         rem_anchor_token(T_INTEGER);
10056         rem_anchor_token(T_IDENTIFIER);
10057         rem_anchor_token(T_FLOATINGPOINT);
10058         rem_anchor_token(T_COLONCOLON);
10059         rem_anchor_token(T_CHARACTER_CONSTANT);
10060         rem_anchor_token('~');
10061         rem_anchor_token('{');
10062         rem_anchor_token(';');
10063         rem_anchor_token('-');
10064         rem_anchor_token('+');
10065         rem_anchor_token('*');
10066         rem_anchor_token('(');
10067         rem_anchor_token('&');
10068         rem_anchor_token('!');
10069         rem_anchor_token('}');
10070
10071         POP_SCOPE();
10072         POP_PARENT();
10073         return statement;
10074 }
10075
10076 /**
10077  * Check for unused global static functions and variables
10078  */
10079 static void check_unused_globals(void)
10080 {
10081         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10082                 return;
10083
10084         for (const entity_t *entity = file_scope->entities; entity != NULL;
10085              entity = entity->base.next) {
10086                 if (!is_declaration(entity))
10087                         continue;
10088
10089                 const declaration_t *declaration = &entity->declaration;
10090                 if (declaration->used                  ||
10091                     declaration->modifiers & DM_UNUSED ||
10092                     declaration->modifiers & DM_USED   ||
10093                     declaration->storage_class != STORAGE_CLASS_STATIC)
10094                         continue;
10095
10096                 warning_t   why;
10097                 char const *s;
10098                 if (entity->kind == ENTITY_FUNCTION) {
10099                         /* inhibit warning for static inline functions */
10100                         if (entity->function.is_inline)
10101                                 continue;
10102
10103                         why = WARN_UNUSED_FUNCTION;
10104                         s   = entity->function.statement != NULL ? "defined" : "declared";
10105                 } else {
10106                         why = WARN_UNUSED_VARIABLE;
10107                         s   = "defined";
10108                 }
10109
10110                 warningf(why, &declaration->base.source_position, "'%#N' %s but not used", entity, s);
10111         }
10112 }
10113
10114 static void parse_global_asm(void)
10115 {
10116         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10117
10118         eat(T_asm);
10119         add_anchor_token(';');
10120         add_anchor_token(')');
10121         add_anchor_token(T_STRING_LITERAL);
10122         expect('(');
10123
10124         rem_anchor_token(T_STRING_LITERAL);
10125         statement->asms.asm_text = parse_string_literals();
10126         statement->base.next     = unit->global_asm;
10127         unit->global_asm         = statement;
10128
10129         rem_anchor_token(')');
10130         expect(')');
10131         rem_anchor_token(';');
10132         expect(';');
10133 }
10134
10135 static void parse_linkage_specification(void)
10136 {
10137         eat(T_extern);
10138
10139         source_position_t const pos     = *HERE;
10140         char const       *const linkage = parse_string_literals().begin;
10141
10142         linkage_kind_t old_linkage = current_linkage;
10143         linkage_kind_t new_linkage;
10144         if (streq(linkage, "C")) {
10145                 new_linkage = LINKAGE_C;
10146         } else if (streq(linkage, "C++")) {
10147                 new_linkage = LINKAGE_CXX;
10148         } else {
10149                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10150                 new_linkage = LINKAGE_C;
10151         }
10152         current_linkage = new_linkage;
10153
10154         if (next_if('{')) {
10155                 parse_externals();
10156                 expect('}');
10157         } else {
10158                 parse_external();
10159         }
10160
10161         assert(current_linkage == new_linkage);
10162         current_linkage = old_linkage;
10163 }
10164
10165 static void parse_external(void)
10166 {
10167         switch (token.kind) {
10168                 case T_extern:
10169                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10170                                 parse_linkage_specification();
10171                         } else {
10172                 DECLARATION_START_NO_EXTERN
10173                 case T_IDENTIFIER:
10174                 case T___extension__:
10175                 /* tokens below are for implicit int */
10176                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10177                               implicit int) */
10178                 case '*':  /* * x; -> int* x; */
10179                 case '(':  /* (x); -> int (x); */
10180                                 PUSH_EXTENSION();
10181                                 parse_external_declaration();
10182                                 POP_EXTENSION();
10183                         }
10184                         return;
10185
10186                 case T_asm:
10187                         parse_global_asm();
10188                         return;
10189
10190                 case T_namespace:
10191                         parse_namespace_definition();
10192                         return;
10193
10194                 case ';':
10195                         if (!strict_mode) {
10196                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10197                                 next_token();
10198                                 return;
10199                         }
10200                         /* FALLTHROUGH */
10201
10202                 default:
10203                         errorf(HERE, "stray %K outside of function", &token);
10204                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10205                                 eat_until_matching_token(token.kind);
10206                         next_token();
10207                         return;
10208         }
10209 }
10210
10211 static void parse_externals(void)
10212 {
10213         add_anchor_token('}');
10214         add_anchor_token(T_EOF);
10215
10216 #ifndef NDEBUG
10217         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10218         unsigned short token_anchor_copy[T_LAST_TOKEN];
10219         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10220 #endif
10221
10222         while (token.kind != T_EOF && token.kind != '}') {
10223 #ifndef NDEBUG
10224                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10225                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10226                         if (count != 0) {
10227                                 /* the anchor set and its copy differs */
10228                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10229                         }
10230                 }
10231                 if (in_gcc_extension) {
10232                         /* an gcc extension scope was not closed */
10233                         internal_errorf(HERE, "Leaked __extension__");
10234                 }
10235 #endif
10236
10237                 parse_external();
10238         }
10239
10240         rem_anchor_token(T_EOF);
10241         rem_anchor_token('}');
10242 }
10243
10244 /**
10245  * Parse a translation unit.
10246  */
10247 static void parse_translation_unit(void)
10248 {
10249         add_anchor_token(T_EOF);
10250
10251         while (true) {
10252                 parse_externals();
10253
10254                 if (token.kind == T_EOF)
10255                         break;
10256
10257                 errorf(HERE, "stray %K outside of function", &token);
10258                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10259                         eat_until_matching_token(token.kind);
10260                 next_token();
10261         }
10262 }
10263
10264 void set_default_visibility(elf_visibility_tag_t visibility)
10265 {
10266         default_visibility = visibility;
10267 }
10268
10269 /**
10270  * Parse the input.
10271  *
10272  * @return  the translation unit or NULL if errors occurred.
10273  */
10274 void start_parsing(void)
10275 {
10276         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10277         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10278         diagnostic_count  = 0;
10279         error_count       = 0;
10280         warning_count     = 0;
10281
10282         print_to_file(stderr);
10283
10284         assert(unit == NULL);
10285         unit = allocate_ast_zero(sizeof(unit[0]));
10286
10287         assert(file_scope == NULL);
10288         file_scope = &unit->scope;
10289
10290         assert(current_scope == NULL);
10291         scope_push(&unit->scope);
10292
10293         create_gnu_builtins();
10294         if (c_mode & _MS)
10295                 create_microsoft_intrinsics();
10296 }
10297
10298 translation_unit_t *finish_parsing(void)
10299 {
10300         assert(current_scope == &unit->scope);
10301         scope_pop(NULL);
10302
10303         assert(file_scope == &unit->scope);
10304         check_unused_globals();
10305         file_scope = NULL;
10306
10307         DEL_ARR_F(environment_stack);
10308         DEL_ARR_F(label_stack);
10309
10310         translation_unit_t *result = unit;
10311         unit = NULL;
10312         return result;
10313 }
10314
10315 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10316  * are given length one. */
10317 static void complete_incomplete_arrays(void)
10318 {
10319         size_t n = ARR_LEN(incomplete_arrays);
10320         for (size_t i = 0; i != n; ++i) {
10321                 declaration_t *const decl = incomplete_arrays[i];
10322                 type_t        *const type = skip_typeref(decl->type);
10323
10324                 if (!is_type_incomplete(type))
10325                         continue;
10326
10327                 source_position_t const *const pos = &decl->base.source_position;
10328                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10329
10330                 type_t *const new_type = duplicate_type(type);
10331                 new_type->array.size_constant     = true;
10332                 new_type->array.has_implicit_size = true;
10333                 new_type->array.size              = 1;
10334
10335                 type_t *const result = identify_new_type(new_type);
10336
10337                 decl->type = result;
10338         }
10339 }
10340
10341 static void prepare_main_collect2(entity_t *const entity)
10342 {
10343         PUSH_SCOPE(&entity->function.statement->compound.scope);
10344
10345         // create call to __main
10346         symbol_t *symbol         = symbol_table_insert("__main");
10347         entity_t *subsubmain_ent
10348                 = create_implicit_function(symbol, &builtin_source_position);
10349
10350         expression_t *ref         = allocate_expression_zero(EXPR_REFERENCE);
10351         type_t       *ftype       = subsubmain_ent->declaration.type;
10352         ref->base.source_position = builtin_source_position;
10353         ref->base.type            = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10354         ref->reference.entity     = subsubmain_ent;
10355
10356         expression_t *call = allocate_expression_zero(EXPR_CALL);
10357         call->base.source_position = builtin_source_position;
10358         call->base.type            = type_void;
10359         call->call.function        = ref;
10360
10361         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10362         expr_statement->base.source_position  = builtin_source_position;
10363         expr_statement->expression.expression = call;
10364
10365         statement_t *statement = entity->function.statement;
10366         assert(statement->kind == STATEMENT_COMPOUND);
10367         compound_statement_t *compounds = &statement->compound;
10368
10369         expr_statement->base.next = compounds->statements;
10370         compounds->statements     = expr_statement;
10371
10372         POP_SCOPE();
10373 }
10374
10375 void parse(void)
10376 {
10377         lookahead_bufpos = 0;
10378         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10379                 next_token();
10380         }
10381         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10382         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10383         parse_translation_unit();
10384         complete_incomplete_arrays();
10385         DEL_ARR_F(incomplete_arrays);
10386         incomplete_arrays = NULL;
10387 }
10388
10389 /**
10390  * Initialize the parser.
10391  */
10392 void init_parser(void)
10393 {
10394         sym_anonymous = symbol_table_insert("<anonymous>");
10395
10396         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10397
10398         init_expression_parsers();
10399         obstack_init(&temp_obst);
10400 }
10401
10402 /**
10403  * Terminate the parser.
10404  */
10405 void exit_parser(void)
10406 {
10407         obstack_free(&temp_obst, NULL);
10408 }