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 <ctype.h>
  24 #include <stdarg.h>
  25 #include <stdbool.h>
  26
  27 #include "adt/strutil.h"
  28 #include "parser.h"
  29 #include "diagnostic.h"
  30 #include "format_check.h"
  31 #include "preprocessor.h"
  32 #include "symbol_t.h"
  33 #include "token_t.h"
  34 #include "types.h"
  35 #include "type_t.h"
  36 #include "type_hash.h"
  37 #include "ast_t.h"
  38 #include "entity_t.h"
  39 #include "attribute_t.h"
  40 #include "lang_features.h"
  41 #include "walk.h"
  42 #include "warning.h"
  43 #include "printer.h"
  44 #include "ast2firm.h"
  45 #include "adt/bitfiddle.h"
  46 #include "adt/error.h"
  47 #include "adt/array.h"
  48
  49 //#define PRINT_TOKENS
  50 #define MAX_LOOKAHEAD 1
  51
  52 typedef struct {
  53         entity_t           *old_entity;
  54         symbol_t           *symbol;
  55         entity_namespace_t  namespc;
  56 } stack_entry_t;
  57
  58 typedef struct declaration_specifiers_t  declaration_specifiers_t;
  59 struct declaration_specifiers_t {
  60         position_t      pos;
  61         storage_class_t storage_class;
  62         unsigned char   alignment;         /**< Alignment, 0 if not set. */
  63         bool            is_inline    : 1;
  64         bool            thread_local : 1;
  65         attribute_t    *attributes;        /**< list of attributes */
  66         type_t         *type;
  67 };
  68
  69 /**
  70  * An environment for parsing initializers (and compound literals).
  71  */
  72 typedef struct parse_initializer_env_t {
  73         type_t     *type;   /**< the type of the initializer. In case of an
  74                                  array type with unspecified size this gets
  75                                  adjusted to the actual size. */
  76         entity_t   *entity; /**< the variable that is initialized if any */
  77         bool        must_be_constant;
  78 } parse_initializer_env_t;
  79
  80 typedef entity_t* (*parsed_declaration_func) (entity_t *declaration, bool is_definition);
  81
  82 /** The current token. */
  83 static token_t              token;
  84 /** The lookahead ring-buffer. */
  85 static token_t              lookahead_buffer[MAX_LOOKAHEAD];
  86 /** Position of the next token in the lookahead buffer. */
  87 static size_t               lookahead_bufpos;
  88 static stack_entry_t       *environment_stack = NULL;
  89 static stack_entry_t       *label_stack       = NULL;
  90 static scope_t             *file_scope        = NULL;
  91 static scope_t             *current_scope     = NULL;
  92 /** Point to the current function declaration if inside a function. */
  93 static function_t          *current_function  = NULL;
  94 static entity_t            *current_entity    = NULL;
  95 static switch_statement_t  *current_switch    = NULL;
  96 static statement_t         *current_loop      = NULL;
  97 static statement_t         *current_parent    = NULL;
  98 static ms_try_statement_t  *current_try       = NULL;
  99 static linkage_kind_t       current_linkage;
 100 static goto_statement_t    *goto_first        = NULL;
 101 static goto_statement_t   **goto_anchor       = NULL;
 102 static label_statement_t   *label_first       = NULL;
 103 static label_statement_t  **label_anchor      = NULL;
 104 /** current translation unit. */
 105 static translation_unit_t  *unit              = NULL;
 106 /** true if we are in an __extension__ context. */
 107 static bool                 in_gcc_extension  = false;
 108 static struct obstack       temp_obst;
 109 static entity_t            *anonymous_entity;
 110 static declaration_t      **incomplete_arrays;
 111 static elf_visibility_tag_t default_visibility = ELF_VISIBILITY_DEFAULT;
 112
 113
 114 #define PUSH_CURRENT_ENTITY(entity) \
 115         entity_t *const new_current_entity = (entity); \
 116         entity_t *const old_current_entity = current_entity; \
 117         ((void)(current_entity = new_current_entity))
 118 #define POP_CURRENT_ENTITY() (assert(current_entity == new_current_entity), (void)(current_entity = old_current_entity))
 119
 120 #define PUSH_PARENT(stmt) \
 121         statement_t *const new_parent = (stmt); \
 122         statement_t *const old_parent = current_parent; \
 123         ((void)(current_parent = new_parent))
 124 #define POP_PARENT() (assert(current_parent == new_parent), (void)(current_parent = old_parent))
 125
 126 #define PUSH_SCOPE(scope) \
 127         size_t   const top       = environment_top(); \
 128         scope_t *const new_scope = (scope); \
 129         scope_t *const old_scope = (new_scope ? scope_push(new_scope) : NULL)
 130 #define PUSH_SCOPE_STATEMENT(scope) PUSH_SCOPE(c_mode & (_C99 | _CXX) ? (scope) : NULL)
 131 #define POP_SCOPE() (new_scope ? assert(current_scope == new_scope), scope_pop(old_scope), environment_pop_to(top) : (void)0)
 132
 133 #define PUSH_EXTENSION() \
 134         (void)0; \
 135         bool const old_gcc_extension = in_gcc_extension; \
 136         while (accept(T___extension__)) { \
 137                 in_gcc_extension = true; \
 138         } \
 139         do {} while (0)
 140 #define POP_EXTENSION() \
 141         ((void)(in_gcc_extension = old_gcc_extension))
 142
 143 /** The token anchor set */
 144 static unsigned short token_anchor_set[T_LAST_TOKEN];
 145
 146 /** The current source position. */
 147 #define HERE (&token.base.pos)
 148
 149 /** true if we are in GCC mode. */
 150 #define GNU_MODE ((c_mode & _GNUC) || in_gcc_extension)
 151
 152 static statement_t *parse_compound_statement(bool inside_expression_statement);
 153 static statement_t *parse_statement(void);
 154
 155 static expression_t *parse_subexpression(precedence_t);
 156 static expression_t *parse_expression(void);
 157 static type_t       *parse_typename(void);
 158 static void          parse_externals(void);
 159 static void          parse_external(void);
 160
 161 static void parse_compound_type_entries(compound_t *compound_declaration);
 162
 163 static void check_call_argument(type_t          *expected_type,
 164                                                                 call_argument_t *argument, unsigned pos);
 165
 166 typedef enum declarator_flags_t {
 167         DECL_FLAGS_NONE             = 0,
 168         DECL_MAY_BE_ABSTRACT        = 1U << 0,
 169         DECL_CREATE_COMPOUND_MEMBER = 1U << 1,
 170         DECL_IS_PARAMETER           = 1U << 2
 171 } declarator_flags_t;
 172
 173 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
 174                                   declarator_flags_t flags);
 175
 176 static void semantic_comparison(binary_expression_t *expression);
 177
 178 #define STORAGE_CLASSES       \
 179         STORAGE_CLASSES_NO_EXTERN \
 180         case T_extern:
 181
 182 #define STORAGE_CLASSES_NO_EXTERN \
 183         case T_typedef:         \
 184         case T_static:          \
 185         case T_auto:            \
 186         case T_register:        \
 187         case T__Thread_local:
 188
 189 #define TYPE_QUALIFIERS     \
 190         case T_const:           \
 191         case T_restrict:        \
 192         case T_volatile:        \
 193         case T_inline:          \
 194         case T__forceinline:    \
 195         case T___attribute__:
 196
 197 #define COMPLEX_SPECIFIERS  \
 198         case T__Complex:
 199 #define IMAGINARY_SPECIFIERS \
 200         case T__Imaginary:
 201
 202 #define TYPE_SPECIFIERS       \
 203         case T__Bool:             \
 204         case T___builtin_va_list: \
 205         case T___typeof__:        \
 206         case T__declspec:         \
 207         case T_bool:              \
 208         case T_char:              \
 209         case T_double:            \
 210         case T_enum:              \
 211         case T_float:             \
 212         case T_int:               \
 213         case T_long:              \
 214         case T_short:             \
 215         case T_signed:            \
 216         case T_struct:            \
 217         case T_union:             \
 218         case T_unsigned:          \
 219         case T_void:              \
 220         case T_wchar_t:           \
 221         case T__int8:             \
 222         case T__int16:            \
 223         case T__int32:            \
 224         case T__int64:            \
 225         case T__int128:           \
 226         COMPLEX_SPECIFIERS        \
 227         IMAGINARY_SPECIFIERS
 228
 229 #define DECLARATION_START   \
 230         STORAGE_CLASSES         \
 231         TYPE_QUALIFIERS         \
 232         TYPE_SPECIFIERS
 233
 234 #define DECLARATION_START_NO_EXTERN \
 235         STORAGE_CLASSES_NO_EXTERN       \
 236         TYPE_QUALIFIERS                 \
 237         TYPE_SPECIFIERS
 238
 239 #define EXPRESSION_START              \
 240         case '!':                         \
 241         case '&':                         \
 242         case '(':                         \
 243         case '*':                         \
 244         case '+':                         \
 245         case '-':                         \
 246         case '~':                         \
 247         case T_ANDAND:                    \
 248         case T_CHARACTER_CONSTANT:        \
 249         case T_NUMBER:                    \
 250         case T_MINUSMINUS:                \
 251         case T_PLUSPLUS:                  \
 252         case T_STRING_LITERAL:            \
 253         case T__Alignof:                  \
 254         case T___FUNCDNAME__:             \
 255         case T___FUNCSIG__:               \
 256         case T___PRETTY_FUNCTION__:       \
 257         case T___builtin_classify_type:   \
 258         case T___builtin_constant_p:      \
 259         case T___builtin_isgreater:       \
 260         case T___builtin_isgreaterequal:  \
 261         case T___builtin_isless:          \
 262         case T___builtin_islessequal:     \
 263         case T___builtin_islessgreater:   \
 264         case T___builtin_isunordered:     \
 265         case T___builtin_offsetof:        \
 266         case T___builtin_va_arg:          \
 267         case T___builtin_va_copy:         \
 268         case T___builtin_va_start:        \
 269         case T___func__:                  \
 270         case T___noop:                    \
 271         case T__assume:                   \
 272         case T_delete:                    \
 273         case T_false:                     \
 274         case T_sizeof:                    \
 275         case T_throw:                     \
 276         case T_true:
 277
 278 /**
 279  * Returns the size of a statement node.
 280  *
 281  * @param kind  the statement kind
 282  */
 283 static size_t get_statement_struct_size(statement_kind_t kind)
 284 {
 285         static const size_t sizes[] = {
 286                 [STATEMENT_ERROR]         = sizeof(statement_base_t),
 287                 [STATEMENT_EMPTY]         = sizeof(statement_base_t),
 288                 [STATEMENT_COMPOUND]      = sizeof(compound_statement_t),
 289                 [STATEMENT_RETURN]        = sizeof(return_statement_t),
 290                 [STATEMENT_DECLARATION]   = sizeof(declaration_statement_t),
 291                 [STATEMENT_IF]            = sizeof(if_statement_t),
 292                 [STATEMENT_SWITCH]        = sizeof(switch_statement_t),
 293                 [STATEMENT_EXPRESSION]    = sizeof(expression_statement_t),
 294                 [STATEMENT_CONTINUE]      = sizeof(statement_base_t),
 295                 [STATEMENT_BREAK]         = sizeof(statement_base_t),
 296                 [STATEMENT_COMPUTED_GOTO] = sizeof(computed_goto_statement_t),
 297                 [STATEMENT_GOTO]          = sizeof(goto_statement_t),
 298                 [STATEMENT_LABEL]         = sizeof(label_statement_t),
 299                 [STATEMENT_CASE_LABEL]    = sizeof(case_label_statement_t),
 300                 [STATEMENT_DO_WHILE]      = sizeof(do_while_statement_t),
 301                 [STATEMENT_FOR]           = sizeof(for_statement_t),
 302                 [STATEMENT_ASM]           = sizeof(asm_statement_t),
 303                 [STATEMENT_MS_TRY]        = sizeof(ms_try_statement_t),
 304                 [STATEMENT_LEAVE]         = sizeof(leave_statement_t)
 305         };
 306         assert((size_t)kind < lengthof(sizes));
 307         assert(sizes[kind] != 0);
 308         return sizes[kind];
 309 }
 310
 311 /**
 312  * Returns the size of an expression node.
 313  *
 314  * @param kind  the expression kind
 315  */
 316 static size_t get_expression_struct_size(expression_kind_t kind)
 317 {
 318         static const size_t sizes[] = {
 319                 [EXPR_ERROR]                      = sizeof(expression_base_t),
 320                 [EXPR_REFERENCE]                  = sizeof(reference_expression_t),
 321                 [EXPR_ENUM_CONSTANT]              = sizeof(reference_expression_t),
 322                 [EXPR_LITERAL_BOOLEAN]            = sizeof(literal_expression_t),
 323                 [EXPR_LITERAL_INTEGER]            = sizeof(literal_expression_t),
 324                 [EXPR_LITERAL_FLOATINGPOINT]      = sizeof(literal_expression_t),
 325                 [EXPR_LITERAL_CHARACTER]          = sizeof(string_literal_expression_t),
 326                 [EXPR_LITERAL_MS_NOOP]            = sizeof(literal_expression_t),
 327                 [EXPR_STRING_LITERAL]             = sizeof(string_literal_expression_t),
 328                 [EXPR_COMPOUND_LITERAL]           = sizeof(compound_literal_expression_t),
 329                 [EXPR_CALL]                       = sizeof(call_expression_t),
 330                 [EXPR_UNARY_FIRST]                = sizeof(unary_expression_t),
 331                 [EXPR_BINARY_FIRST]               = sizeof(binary_expression_t),
 332                 [EXPR_CONDITIONAL]                = sizeof(conditional_expression_t),
 333                 [EXPR_SELECT]                     = sizeof(select_expression_t),
 334                 [EXPR_ARRAY_ACCESS]               = sizeof(array_access_expression_t),
 335                 [EXPR_SIZEOF]                     = sizeof(typeprop_expression_t),
 336                 [EXPR_ALIGNOF]                    = sizeof(typeprop_expression_t),
 337                 [EXPR_CLASSIFY_TYPE]              = sizeof(classify_type_expression_t),
 338                 [EXPR_FUNCNAME]                   = sizeof(funcname_expression_t),
 339                 [EXPR_BUILTIN_CONSTANT_P]         = sizeof(builtin_constant_expression_t),
 340                 [EXPR_BUILTIN_TYPES_COMPATIBLE_P] = sizeof(builtin_types_compatible_expression_t),
 341                 [EXPR_OFFSETOF]                   = sizeof(offsetof_expression_t),
 342                 [EXPR_VA_START]                   = sizeof(va_start_expression_t),
 343                 [EXPR_VA_ARG]                     = sizeof(va_arg_expression_t),
 344                 [EXPR_VA_COPY]                    = sizeof(va_copy_expression_t),
 345                 [EXPR_STATEMENT]                  = sizeof(statement_expression_t),
 346                 [EXPR_LABEL_ADDRESS]              = sizeof(label_address_expression_t),
 347         };
 348         if (kind >= EXPR_UNARY_FIRST && kind <= EXPR_UNARY_LAST) {
 349                 return sizes[EXPR_UNARY_FIRST];
 350         }
 351         if (kind >= EXPR_BINARY_FIRST && kind <= EXPR_BINARY_LAST) {
 352                 return sizes[EXPR_BINARY_FIRST];
 353         }
 354         assert((size_t)kind < lengthof(sizes));
 355         assert(sizes[kind] != 0);
 356         return sizes[kind];
 357 }
 358
 359 /**
 360  * Allocate a statement node of given kind and initialize all
 361  * fields with zero. Sets its source position to the position
 362  * of the current token.
 363  */
 364 static statement_t *allocate_statement_zero(statement_kind_t kind)
 365 {
 366         size_t       size = get_statement_struct_size(kind);
 367         statement_t *res  = allocate_ast_zero(size);
 368
 369         res->base.kind   = kind;
 370         res->base.parent = current_parent;
 371         res->base.pos    = *HERE;
 372         return res;
 373 }
 374
 375 /**
 376  * Allocate an expression node of given kind and initialize all
 377  * fields with zero.
 378  *
 379  * @param kind  the kind of the expression to allocate
 380  */
 381 static expression_t *allocate_expression_zero(expression_kind_t kind)
 382 {
 383         size_t        size = get_expression_struct_size(kind);
 384         expression_t *res  = allocate_ast_zero(size);
 385
 386         res->base.kind = kind;
 387         res->base.type = type_error_type;
 388         res->base.pos  = *HERE;
 389         return res;
 390 }
 391
 392 /**
 393  * Creates a new invalid expression at the source position
 394  * of the current token.
 395  */
 396 static expression_t *create_error_expression(void)
 397 {
 398         expression_t *expression = allocate_expression_zero(EXPR_ERROR);
 399         expression->base.type = type_error_type;
 400         return expression;
 401 }
 402
 403 /**
 404  * Creates a new invalid statement.
 405  */
 406 static statement_t *create_error_statement(void)
 407 {
 408         return allocate_statement_zero(STATEMENT_ERROR);
 409 }
 410
 411 /**
 412  * Allocate a new empty statement.
 413  */
 414 static statement_t *create_empty_statement(void)
 415 {
 416         return allocate_statement_zero(STATEMENT_EMPTY);
 417 }
 418
 419 /**
 420  * Returns the size of an initializer node.
 421  *
 422  * @param kind  the initializer kind
 423  */
 424 static size_t get_initializer_size(initializer_kind_t kind)
 425 {
 426         static const size_t sizes[] = {
 427                 [INITIALIZER_VALUE]       = sizeof(initializer_value_t),
 428                 [INITIALIZER_STRING]      = sizeof(initializer_value_t),
 429                 [INITIALIZER_LIST]        = sizeof(initializer_list_t),
 430                 [INITIALIZER_DESIGNATOR]  = sizeof(initializer_designator_t)
 431         };
 432         assert((size_t)kind < lengthof(sizes));
 433         assert(sizes[kind] != 0);
 434         return sizes[kind];
 435 }
 436
 437 /**
 438  * Allocate an initializer node of given kind and initialize all
 439  * fields with zero.
 440  */
 441 static initializer_t *allocate_initializer_zero(initializer_kind_t kind)
 442 {
 443         initializer_t *result = allocate_ast_zero(get_initializer_size(kind));
 444         result->kind          = kind;
 445
 446         return result;
 447 }
 448
 449 /**
 450  * Returns the index of the top element of the environment stack.
 451  */
 452 static size_t environment_top(void)
 453 {
 454         return ARR_LEN(environment_stack);
 455 }
 456
 457 /**
 458  * Returns the index of the top element of the global label stack.
 459  */
 460 static size_t label_top(void)
 461 {
 462         return ARR_LEN(label_stack);
 463 }
 464
 465 /**
 466  * Return the next token.
 467  */
 468 static inline void next_token(void)
 469 {
 470         token                              = lookahead_buffer[lookahead_bufpos];
 471         lookahead_buffer[lookahead_bufpos] = pp_token;
 472         next_preprocessing_token();
 473
 474         lookahead_bufpos = (lookahead_bufpos + 1) % MAX_LOOKAHEAD;
 475
 476 #ifdef PRINT_TOKENS
 477         print_token(stderr, &token);
 478         fprintf(stderr, "\n");
 479 #endif
 480 }
 481
 482 static inline void eat(token_kind_t const kind)
 483 {
 484         assert(token.kind == kind);
 485         (void)kind;
 486         next_token();
 487 }
 488
 489 /**
 490  * Consume the current token, if it is of the expected kind.
 491  *
 492  * @param  kind  The kind of token to consume.
 493  * @return Whether the token was consumed.
 494  */
 495 static inline bool accept(token_kind_t const kind)
 496 {
 497         if (token.kind == kind) {
 498                 eat(kind);
 499                 return true;
 500         } else {
 501                 return false;
 502         }
 503 }
 504
 505 /**
 506  * Return the next token with a given lookahead.
 507  */
 508 static inline const token_t *look_ahead(size_t num)
 509 {
 510         assert(0 < num && num <= MAX_LOOKAHEAD);
 511         size_t pos = (lookahead_bufpos + num - 1) % MAX_LOOKAHEAD;
 512         return &lookahead_buffer[pos];
 513 }
 514
 515 /**
 516  * Adds a token type to the token type anchor set (a multi-set).
 517  */
 518 static void add_anchor_token(token_kind_t const token_kind)
 519 {
 520         assert(token_kind < T_LAST_TOKEN);
 521         ++token_anchor_set[token_kind];
 522 }
 523
 524 /**
 525  * Remove a token type from the token type anchor set (a multi-set).
 526  */
 527 static void rem_anchor_token(token_kind_t const token_kind)
 528 {
 529         assert(token_kind < T_LAST_TOKEN);
 530         assert(token_anchor_set[token_kind] != 0);
 531         --token_anchor_set[token_kind];
 532 }
 533
 534 /**
 535  * Eat tokens until a matching token type is found.
 536  */
 537 static void eat_until_matching_token(token_kind_t const type)
 538 {
 539         token_kind_t end_token;
 540         switch (type) {
 541                 case '(': end_token = ')';  break;
 542                 case '{': end_token = '}';  break;
 543                 case '[': end_token = ']';  break;
 544                 default:  end_token = type; break;
 545         }
 546
 547         unsigned parenthesis_count = 0;
 548         unsigned brace_count       = 0;
 549         unsigned bracket_count     = 0;
 550         while (token.kind        != end_token ||
 551                parenthesis_count != 0         ||
 552                brace_count       != 0         ||
 553                bracket_count     != 0) {
 554                 switch (token.kind) {
 555                 case T_EOF: return;
 556                 case '(': ++parenthesis_count; break;
 557                 case '{': ++brace_count;       break;
 558                 case '[': ++bracket_count;     break;
 559
 560                 case ')':
 561                         if (parenthesis_count > 0)
 562                                 --parenthesis_count;
 563                         goto check_stop;
 564
 565                 case '}':
 566                         if (brace_count > 0)
 567                                 --brace_count;
 568                         goto check_stop;
 569
 570                 case ']':
 571                         if (bracket_count > 0)
 572                                 --bracket_count;
 573 check_stop:
 574                         if (token.kind        == end_token &&
 575                             parenthesis_count == 0         &&
 576                             brace_count       == 0         &&
 577                             bracket_count     == 0)
 578                                 return;
 579                         break;
 580
 581                 default:
 582                         break;
 583                 }
 584                 next_token();
 585         }
 586 }
 587
 588 /**
 589  * Eat input tokens until an anchor is found.
 590  */
 591 static void eat_until_anchor(void)
 592 {
 593         while (token_anchor_set[token.kind] == 0) {
 594                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
 595                         eat_until_matching_token(token.kind);
 596                 next_token();
 597         }
 598 }
 599
 600 /**
 601  * Eat a whole block from input tokens.
 602  */
 603 static void eat_block(void)
 604 {
 605         eat_until_matching_token('{');
 606         accept('}');
 607 }
 608
 609 /**
 610  * Report a parse error because an expected token was not found.
 611  */
 612 static
 613 #if defined __GNUC__ && __GNUC__ >= 4
 614 __attribute__((sentinel))
 615 #endif
 616 void parse_error_expected(const char *message, ...)
 617 {
 618         if (message != NULL) {
 619                 errorf(HERE, "%s", message);
 620         }
 621         va_list ap;
 622         va_start(ap, message);
 623         errorf(HERE, "got %K, expected %#k", &token, &ap, ", ");
 624         va_end(ap);
 625 }
 626
 627 /**
 628  * Report an incompatible type.
 629  */
 630 static void type_error_incompatible(const char *msg,
 631                 const position_t *pos, type_t *type1, type_t *type2)
 632 {
 633         errorf(pos, "%s, incompatible types: '%T' - '%T'", msg, type1, type2);
 634 }
 635
 636 static bool skip_till(token_kind_t const expected, char const *const context)
 637 {
 638         if (UNLIKELY(token.kind != expected)) {
 639                 parse_error_expected(context, expected, NULL);
 640                 add_anchor_token(expected);
 641                 eat_until_anchor();
 642                 rem_anchor_token(expected);
 643                 if (token.kind != expected)
 644                         return false;
 645         }
 646         return true;
 647 }
 648
 649 /**
 650  * Expect the current token is the expected token.
 651  * If not, generate an error and skip until the next anchor.
 652  */
 653 static void expect(token_kind_t const expected)
 654 {
 655         if (skip_till(expected, NULL))
 656                 eat(expected);
 657 }
 658
 659 static symbol_t *expect_identifier(char const *const context,
 660                                    position_t *const pos)
 661 {
 662         if (!skip_till(T_IDENTIFIER, context))
 663                 return NULL;
 664         symbol_t *const sym = token.base.symbol;
 665         if (pos)
 666                 *pos = *HERE;
 667         eat(T_IDENTIFIER);
 668         return sym;
 669 }
 670
 671 /**
 672  * Push a given scope on the scope stack and make it the
 673  * current scope
 674  */
 675 static scope_t *scope_push(scope_t *new_scope)
 676 {
 677         if (current_scope != NULL) {
 678                 new_scope->depth = current_scope->depth + 1;
 679         }
 680
 681         scope_t *old_scope = current_scope;
 682         current_scope      = new_scope;
 683         return old_scope;
 684 }
 685
 686 /**
 687  * Pop the current scope from the scope stack.
 688  */
 689 static void scope_pop(scope_t *old_scope)
 690 {
 691         current_scope = old_scope;
 692 }
 693
 694 /**
 695  * Search an entity by its symbol in a given namespace.
 696  */
 697 static entity_t *get_entity(const symbol_t *const symbol,
 698                             namespace_tag_t namespc)
 699 {
 700         entity_t *entity = symbol->entity;
 701         for (; entity != NULL; entity = entity->base.symbol_next) {
 702                 if ((namespace_tag_t)entity->base.namespc == namespc)
 703                         return entity;
 704         }
 705
 706         return NULL;
 707 }
 708
 709 /* §6.2.3:1 24)  There is only one name space for tags even though three are
 710  * possible. */
 711 static entity_t *get_tag(symbol_t const *const symbol,
 712                          entity_kind_tag_t const kind)
 713 {
 714         entity_t *entity = get_entity(symbol, NAMESPACE_TAG);
 715         if (entity != NULL && (entity_kind_tag_t)entity->kind != kind) {
 716                 errorf(HERE,
 717                                 "'%Y' defined as wrong kind of tag (previous definition %P)",
 718                                 symbol, &entity->base.pos);
 719                 entity = NULL;
 720         }
 721         return entity;
 722 }
 723
 724 /**
 725  * pushs an entity on the environment stack and links the corresponding symbol
 726  * it.
 727  */
 728 static void stack_push(stack_entry_t **stack_ptr, entity_t *entity)
 729 {
 730         symbol_t           *symbol  = entity->base.symbol;
 731         entity_namespace_t  namespc = entity->base.namespc;
 732         assert(namespc != 0);
 733
 734         /* replace/add entity into entity list of the symbol */
 735         entity_t **anchor;
 736         entity_t  *iter;
 737         for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 738                 iter = *anchor;
 739                 if (iter == NULL)
 740                         break;
 741
 742                 /* replace an entry? */
 743                 if (iter->base.namespc == namespc) {
 744                         entity->base.symbol_next = iter->base.symbol_next;
 745                         break;
 746                 }
 747         }
 748         *anchor = entity;
 749
 750         /* remember old declaration */
 751         stack_entry_t entry;
 752         entry.symbol     = symbol;
 753         entry.old_entity = iter;
 754         entry.namespc    = namespc;
 755         ARR_APP1(stack_entry_t, *stack_ptr, entry);
 756 }
 757
 758 /**
 759  * Push an entity on the environment stack.
 760  */
 761 static void environment_push(entity_t *entity)
 762 {
 763         assert(entity->base.pos.input_name != NULL);
 764         assert(entity->base.parent_scope != NULL);
 765         stack_push(&environment_stack, entity);
 766 }
 767
 768 /**
 769  * Push a declaration on the global label stack.
 770  *
 771  * @param declaration  the declaration
 772  */
 773 static void label_push(entity_t *label)
 774 {
 775         /* we abuse the parameters scope as parent for the labels */
 776         label->base.parent_scope = &current_function->parameters;
 777         stack_push(&label_stack, label);
 778 }
 779
 780 /**
 781  * pops symbols from the environment stack until @p new_top is the top element
 782  */
 783 static void stack_pop_to(stack_entry_t **stack_ptr, size_t new_top)
 784 {
 785         stack_entry_t *stack = *stack_ptr;
 786         size_t         top   = ARR_LEN(stack);
 787         size_t         i;
 788
 789         assert(new_top <= top);
 790         if (new_top == top)
 791                 return;
 792
 793         for (i = top; i > new_top; --i) {
 794                 stack_entry_t *entry = &stack[i - 1];
 795
 796                 entity_t           *old_entity = entry->old_entity;
 797                 symbol_t           *symbol     = entry->symbol;
 798                 entity_namespace_t  namespc    = entry->namespc;
 799
 800                 /* replace with old_entity/remove */
 801                 entity_t **anchor;
 802                 entity_t  *iter;
 803                 for (anchor = &symbol->entity; ; anchor = &iter->base.symbol_next) {
 804                         iter = *anchor;
 805                         assert(iter != NULL);
 806                         /* replace an entry? */
 807                         if (iter->base.namespc == namespc)
 808                                 break;
 809                 }
 810
 811                 /* restore definition from outer scopes (if there was one) */
 812                 if (old_entity != NULL) {
 813                         old_entity->base.symbol_next = iter->base.symbol_next;
 814                         *anchor                      = old_entity;
 815                 } else {
 816                         /* remove entry from list */
 817                         *anchor = iter->base.symbol_next;
 818                 }
 819         }
 820
 821         ARR_SHRINKLEN(*stack_ptr, new_top);
 822 }
 823
 824 /**
 825  * Pop all entries from the environment stack until the new_top
 826  * is reached.
 827  *
 828  * @param new_top  the new stack top
 829  */
 830 static void environment_pop_to(size_t new_top)
 831 {
 832         stack_pop_to(&environment_stack, new_top);
 833 }
 834
 835 /**
 836  * Pop all entries from the global label stack until the new_top
 837  * is reached.
 838  *
 839  * @param new_top  the new stack top
 840  */
 841 static void label_pop_to(size_t new_top)
 842 {
 843         stack_pop_to(&label_stack, new_top);
 844 }
 845
 846 static atomic_type_kind_t get_akind(const type_t *type)
 847 {
 848         assert(type->kind == TYPE_ATOMIC || type->kind == TYPE_COMPLEX
 849                || type->kind == TYPE_IMAGINARY || type->kind == TYPE_ENUM);
 850         return type->atomic.akind;
 851 }
 852
 853 /**
 854  * §6.3.1.1:2  Do integer promotion for a given type.
 855  *
 856  * @param type  the type to promote
 857  * @return the promoted type
 858  */
 859 static type_t *promote_integer(type_t *type)
 860 {
 861         if (get_akind_rank(get_akind(type)) < get_akind_rank(ATOMIC_TYPE_INT))
 862                 type = type_int;
 863
 864         return type;
 865 }
 866
 867 /**
 868  * Check if a given expression represents a null pointer constant.
 869  *
 870  * @param expression  the expression to check
 871  */
 872 static bool is_null_pointer_constant(const expression_t *expression)
 873 {
 874         /* skip void* cast */
 875         if (expression->kind == EXPR_UNARY_CAST) {
 876                 type_t *const type = skip_typeref(expression->base.type);
 877                 if (types_compatible(type, type_void_ptr))
 878                         expression = expression->unary.value;
 879         }
 880
 881         type_t *const type = skip_typeref(expression->base.type);
 882         if (!is_type_integer(type))
 883                 return false;
 884         switch (is_constant_expression(expression)) {
 885                 case EXPR_CLASS_ERROR:    return true;
 886                 case EXPR_CLASS_CONSTANT: return !fold_constant_to_bool(expression);
 887                 default:                  return false;
 888         }
 889 }
 890
 891 /**
 892  * Create an implicit cast expression.
 893  *
 894  * @param expression  the expression to cast
 895  * @param dest_type   the destination type
 896  */
 897 static expression_t *create_implicit_cast(expression_t *expression,
 898                                           type_t *dest_type)
 899 {
 900         type_t *const source_type = expression->base.type;
 901
 902         if (source_type == dest_type)
 903                 return expression;
 904
 905         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
 906         cast->unary.value   = expression;
 907         cast->base.type     = dest_type;
 908         cast->base.implicit = true;
 909
 910         return cast;
 911 }
 912
 913 typedef enum assign_error_t {
 914         ASSIGN_SUCCESS,
 915         ASSIGN_ERROR_INCOMPATIBLE,
 916         ASSIGN_ERROR_POINTER_QUALIFIER_MISSING,
 917         ASSIGN_WARNING_POINTER_INCOMPATIBLE,
 918         ASSIGN_WARNING_POINTER_FROM_INT,
 919         ASSIGN_WARNING_INT_FROM_POINTER
 920 } assign_error_t;
 921
 922 static void report_assign_error(assign_error_t error, type_t *orig_type_left, expression_t const *const right, char const *const context, position_t const *const pos)
 923 {
 924         type_t *const orig_type_right = right->base.type;
 925         type_t *const type_left       = skip_typeref(orig_type_left);
 926         type_t *const type_right      = skip_typeref(orig_type_right);
 927
 928         switch (error) {
 929         case ASSIGN_SUCCESS:
 930                 return;
 931         case ASSIGN_ERROR_INCOMPATIBLE:
 932                 errorf(pos, "destination type '%T' in %s is incompatible with type '%T'", orig_type_left, context, orig_type_right);
 933                 return;
 934
 935         case ASSIGN_ERROR_POINTER_QUALIFIER_MISSING: {
 936                 type_t *points_to_left  = skip_typeref(type_left->pointer.points_to);
 937                 type_t *points_to_right = skip_typeref(type_right->pointer.points_to);
 938
 939                 /* the left type has all qualifiers from the right type */
 940                 unsigned missing_qualifiers = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 941                 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);
 942                 return;
 943         }
 944
 945         case ASSIGN_WARNING_POINTER_INCOMPATIBLE:
 946                 warningf(WARN_OTHER, pos, "destination type '%T' in %s is incompatible with '%E' of type '%T'", orig_type_left, context, right, orig_type_right);
 947                 return;
 948
 949         case ASSIGN_WARNING_POINTER_FROM_INT:
 950                 warningf(WARN_OTHER, pos, "%s makes pointer '%T' from integer '%T' without a cast", context, orig_type_left, orig_type_right);
 951                 return;
 952
 953         case ASSIGN_WARNING_INT_FROM_POINTER:
 954                 warningf(WARN_OTHER, pos, "%s makes integer '%T' from pointer '%T' without a cast", context, orig_type_left, orig_type_right);
 955                 return;
 956
 957         default:
 958                 panic("invalid error value");
 959         }
 960 }
 961
 962 /** Implements the rules from §6.5.16.1 */
 963 static assign_error_t semantic_assign(type_t *orig_type_left,
 964                                       const expression_t *const right)
 965 {
 966         type_t *const orig_type_right = right->base.type;
 967         type_t *const type_left       = skip_typeref(orig_type_left);
 968         type_t *const type_right      = skip_typeref(orig_type_right);
 969
 970         if (is_type_pointer(type_left)) {
 971                 if (is_null_pointer_constant(right)) {
 972                         return ASSIGN_SUCCESS;
 973                 } else if (is_type_pointer(type_right)) {
 974                         type_t *points_to_left
 975                                 = skip_typeref(type_left->pointer.points_to);
 976                         type_t *points_to_right
 977                                 = skip_typeref(type_right->pointer.points_to);
 978                         assign_error_t res = ASSIGN_SUCCESS;
 979
 980                         /* the left type has all qualifiers from the right type */
 981                         unsigned missing_qualifiers
 982                                 = points_to_right->base.qualifiers & ~points_to_left->base.qualifiers;
 983                         if (missing_qualifiers != 0) {
 984                                 res = ASSIGN_ERROR_POINTER_QUALIFIER_MISSING;
 985                         }
 986
 987                         points_to_left  = get_unqualified_type(points_to_left);
 988                         points_to_right = get_unqualified_type(points_to_right);
 989
 990                         if (is_type_void(points_to_left))
 991                                 return res;
 992
 993                         if (is_type_void(points_to_right)) {
 994                                 /* ISO/IEC 14882:1998(E) §C.1.2:6 */
 995                                 return c_mode & _CXX ? ASSIGN_ERROR_INCOMPATIBLE : res;
 996                         }
 997
 998                         if (!types_compatible(points_to_left, points_to_right)) {
 999                                 return ASSIGN_WARNING_POINTER_INCOMPATIBLE;
1000                         }
1001
1002                         return res;
1003                 } else if (is_type_integer(type_right)) {
1004                         return ASSIGN_WARNING_POINTER_FROM_INT;
1005                 }
1006         } else if ((is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) ||
1007                         (is_type_atomic(type_left, ATOMIC_TYPE_BOOL)
1008                                 && is_type_pointer(type_right))) {
1009                 return ASSIGN_SUCCESS;
1010         } else if (is_type_compound(type_left) && is_type_compound(type_right)) {
1011                 type_t *const unqual_type_left  = get_unqualified_type(type_left);
1012                 type_t *const unqual_type_right = get_unqualified_type(type_right);
1013                 if (types_compatible(unqual_type_left, unqual_type_right)) {
1014                         return ASSIGN_SUCCESS;
1015                 }
1016         } else if (is_type_integer(type_left) && is_type_pointer(type_right)) {
1017                 return ASSIGN_WARNING_INT_FROM_POINTER;
1018         }
1019
1020         if (!is_type_valid(type_left) || !is_type_valid(type_right))
1021                 return ASSIGN_SUCCESS;
1022
1023         return ASSIGN_ERROR_INCOMPATIBLE;
1024 }
1025
1026 static expression_t *parse_constant_expression(void)
1027 {
1028         expression_t *result = parse_subexpression(PREC_CONDITIONAL);
1029
1030         if (is_constant_expression(result) == EXPR_CLASS_VARIABLE) {
1031                 errorf(&result->base.pos, "expression '%E' is not constant", result);
1032         }
1033
1034         return result;
1035 }
1036
1037 static expression_t *parse_assignment_expression(void)
1038 {
1039         return parse_subexpression(PREC_ASSIGNMENT);
1040 }
1041
1042 static void append_string(string_t const *const s)
1043 {
1044         /* FIXME Using the ast_obstack is a hack.  Using the symbol_obstack is not
1045          * possible, because other tokens are grown there alongside. */
1046         obstack_grow(&ast_obstack, s->begin, s->size);
1047 }
1048
1049 static string_t finish_string(string_encoding_t const enc)
1050 {
1051         obstack_1grow(&ast_obstack, '\0');
1052         size_t      const size   = obstack_object_size(&ast_obstack) - 1;
1053         char const *const string = obstack_finish(&ast_obstack);
1054         return (string_t){ string, size, enc };
1055 }
1056
1057 static string_t concat_string_literals(void)
1058 {
1059         assert(token.kind == T_STRING_LITERAL);
1060
1061         string_t result;
1062         if (look_ahead(1)->kind == T_STRING_LITERAL) {
1063                 append_string(&token.literal.string);
1064                 eat(T_STRING_LITERAL);
1065                 warningf(WARN_TRADITIONAL, HERE, "traditional C rejects string constant concatenation");
1066                 string_encoding_t enc = token.literal.string.encoding;
1067                 do {
1068                         string_encoding_t const new_enc = token.literal.string.encoding;
1069                         if (new_enc != enc && new_enc != STRING_ENCODING_CHAR) {
1070                                 if (enc == STRING_ENCODING_CHAR) {
1071                                         enc = new_enc;
1072                                 } else {
1073                                         errorf(HERE, "concatenating string literals with encodings %s and %s", get_string_encoding_prefix(enc), get_string_encoding_prefix(new_enc));
1074                                 }
1075                         }
1076                         append_string(&token.literal.string);
1077                         eat(T_STRING_LITERAL);
1078                 } while (token.kind == T_STRING_LITERAL);
1079                 result = finish_string(enc);
1080         } else {
1081                 result = token.literal.string;
1082                 eat(T_STRING_LITERAL);
1083         }
1084
1085         return result;
1086 }
1087
1088 static string_t parse_string_literals(char const *const context)
1089 {
1090         if (!skip_till(T_STRING_LITERAL, context))
1091                 return (string_t){ "", 0, STRING_ENCODING_CHAR };
1092
1093         position_t const pos = *HERE;
1094         string_t   const res = concat_string_literals();
1095
1096         if (res.encoding != STRING_ENCODING_CHAR) {
1097                 errorf(&pos, "expected plain string literal, got %s string literal", get_string_encoding_prefix(res.encoding));
1098         }
1099
1100         return res;
1101 }
1102
1103 static attribute_t *allocate_attribute_zero(attribute_kind_t kind)
1104 {
1105         attribute_t *attribute = allocate_ast_zero(sizeof(*attribute));
1106         attribute->kind = kind;
1107         attribute->pos  = *HERE;
1108         return attribute;
1109 }
1110
1111 /**
1112  * Parse (gcc) attribute argument. From gcc comments in gcc source:
1113  *
1114  *  attribute:
1115  *    __attribute__ ( ( attribute-list ) )
1116  *
1117  *  attribute-list:
1118  *    attrib
1119  *    attribute_list , attrib
1120  *
1121  *  attrib:
1122  *    empty
1123  *    any-word
1124  *    any-word ( identifier )
1125  *    any-word ( identifier , nonempty-expr-list )
1126  *    any-word ( expr-list )
1127  *
1128  *  where the "identifier" must not be declared as a type, and
1129  *  "any-word" may be any identifier (including one declared as a
1130  *  type), a reserved word storage class specifier, type specifier or
1131  *  type qualifier.  ??? This still leaves out most reserved keywords
1132  *  (following the old parser), shouldn't we include them, and why not
1133  *  allow identifiers declared as types to start the arguments?
1134  *
1135  *  Matze: this all looks confusing and little systematic, so we're even less
1136  *  strict and parse any list of things which are identifiers or
1137  *  (assignment-)expressions.
1138  */
1139 static attribute_argument_t *parse_attribute_arguments(void)
1140 {
1141         attribute_argument_t  *first  = NULL;
1142         attribute_argument_t **anchor = &first;
1143         if (token.kind != ')') do {
1144                 attribute_argument_t *argument = allocate_ast_zero(sizeof(*argument));
1145
1146                 /* is it an identifier */
1147                 if (token.kind == T_IDENTIFIER
1148                                 && (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
1149                         argument->kind     = ATTRIBUTE_ARGUMENT_SYMBOL;
1150                         argument->v.symbol = token.base.symbol;
1151                         eat(T_IDENTIFIER);
1152                 } else {
1153                         /* must be an expression */
1154                         expression_t *expression = parse_assignment_expression();
1155
1156                         argument->kind         = ATTRIBUTE_ARGUMENT_EXPRESSION;
1157                         argument->v.expression = expression;
1158                 }
1159
1160                 /* append argument */
1161                 *anchor = argument;
1162                 anchor  = &argument->next;
1163         } while (accept(','));
1164         expect(')');
1165         return first;
1166 }
1167
1168 static attribute_t *parse_attribute_asm(void)
1169 {
1170         attribute_t *attribute = allocate_attribute_zero(ATTRIBUTE_GNU_ASM);
1171         eat(T_asm);
1172         expect('(');
1173         attribute->a.arguments = parse_attribute_arguments();
1174         return attribute;
1175 }
1176
1177 static attribute_t *parse_attribute_gnu_single(void)
1178 {
1179         /* parse "any-word" */
1180         symbol_t *const symbol = token.base.symbol;
1181         if (symbol == NULL) {
1182                 parse_error_expected("while parsing attribute((", T_IDENTIFIER, NULL);
1183                 return NULL;
1184         }
1185
1186         attribute_kind_t  kind;
1187         char const *const name = symbol->string;
1188         for (kind = ATTRIBUTE_GNU_FIRST;; ++kind) {
1189                 if (kind > ATTRIBUTE_GNU_LAST) {
1190                         /* special case for "__const" */
1191                         if (token.kind == T_const) {
1192                                 kind = ATTRIBUTE_GNU_CONST;
1193                                 break;
1194                         }
1195
1196                         warningf(WARN_ATTRIBUTE, HERE, "unknown attribute '%s' ignored", name);
1197                         /* TODO: we should still save the attribute in the list... */
1198                         kind = ATTRIBUTE_UNKNOWN;
1199                         break;
1200                 }
1201
1202                 const char *attribute_name = get_attribute_name(kind);
1203                 if (attribute_name != NULL && streq_underscore(attribute_name, name))
1204                         break;
1205         }
1206
1207         attribute_t *attribute = allocate_attribute_zero(kind);
1208         next_token();
1209
1210         /* parse arguments */
1211         if (accept('('))
1212                 attribute->a.arguments = parse_attribute_arguments();
1213
1214         return attribute;
1215 }
1216
1217 static attribute_t *parse_attribute_gnu(void)
1218 {
1219         attribute_t  *first  = NULL;
1220         attribute_t **anchor = &first;
1221
1222         eat(T___attribute__);
1223         add_anchor_token(')');
1224         add_anchor_token(',');
1225         expect('(');
1226         expect('(');
1227
1228         if (token.kind != ')') do {
1229                 attribute_t *attribute = parse_attribute_gnu_single();
1230                 if (attribute) {
1231                         *anchor = attribute;
1232                         anchor  = &attribute->next;
1233                 }
1234         } while (accept(','));
1235         rem_anchor_token(',');
1236         rem_anchor_token(')');
1237
1238         expect(')');
1239         expect(')');
1240         return first;
1241 }
1242
1243 /** Parse attributes. */
1244 static attribute_t *parse_attributes(attribute_t *first)
1245 {
1246         attribute_t **anchor = &first;
1247         for (;;) {
1248                 while (*anchor != NULL)
1249                         anchor = &(*anchor)->next;
1250
1251                 attribute_t *attribute;
1252                 switch (token.kind) {
1253                 case T___attribute__:
1254                         attribute = parse_attribute_gnu();
1255                         if (attribute == NULL)
1256                                 continue;
1257                         break;
1258
1259                 case T_asm:
1260                         attribute = parse_attribute_asm();
1261                         break;
1262
1263                 case T_cdecl:
1264                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_CDECL);
1265                         eat(T_cdecl);
1266                         break;
1267
1268                 case T__fastcall:
1269                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FASTCALL);
1270                         eat(T__fastcall);
1271                         break;
1272
1273                 case T__forceinline:
1274                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_FORCEINLINE);
1275                         eat(T__forceinline);
1276                         break;
1277
1278                 case T__stdcall:
1279                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_STDCALL);
1280                         eat(T__stdcall);
1281                         break;
1282
1283                 case T___thiscall:
1284                         /* TODO record modifier */
1285                         warningf(WARN_OTHER, HERE, "Ignoring declaration modifier %K", &token);
1286                         attribute = allocate_attribute_zero(ATTRIBUTE_MS_THISCALL);
1287                         eat(T___thiscall);
1288                         break;
1289
1290                 default:
1291                         return first;
1292                 }
1293
1294                 *anchor = attribute;
1295                 anchor  = &attribute->next;
1296         }
1297 }
1298
1299 static void mark_vars_read(expression_t *expr, entity_t *lhs_ent);
1300
1301 static entity_t *determine_lhs_ent(expression_t *const expr,
1302                                    entity_t *lhs_ent)
1303 {
1304         switch (expr->kind) {
1305                 case EXPR_REFERENCE: {
1306                         entity_t *const entity = expr->reference.entity;
1307                         /* we should only find variables as lvalues... */
1308                         if (entity->base.kind != ENTITY_VARIABLE
1309                                         && entity->base.kind != ENTITY_PARAMETER)
1310                                 return NULL;
1311
1312                         return entity;
1313                 }
1314
1315                 case EXPR_ARRAY_ACCESS: {
1316                         expression_t *const ref = expr->array_access.array_ref;
1317                         entity_t     *      ent = NULL;
1318                         if (is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1319                                 ent     = determine_lhs_ent(ref, lhs_ent);
1320                                 lhs_ent = ent;
1321                         } else {
1322                                 mark_vars_read(ref, lhs_ent);
1323                         }
1324                         mark_vars_read(expr->array_access.index, lhs_ent);
1325                         return ent;
1326                 }
1327
1328                 case EXPR_SELECT: {
1329                         mark_vars_read(expr->select.compound, lhs_ent);
1330                         if (is_type_compound(skip_typeref(expr->base.type)))
1331                                 return determine_lhs_ent(expr->select.compound, lhs_ent);
1332                         return NULL;
1333                 }
1334
1335                 case EXPR_UNARY_DEREFERENCE: {
1336                         expression_t *const val = expr->unary.value;
1337                         if (val->kind == EXPR_UNARY_TAKE_ADDRESS) {
1338                                 /* *&x is a NOP */
1339                                 return determine_lhs_ent(val->unary.value, lhs_ent);
1340                         } else {
1341                                 mark_vars_read(val, NULL);
1342                                 return NULL;
1343                         }
1344                 }
1345
1346                 default:
1347                         mark_vars_read(expr, NULL);
1348                         return NULL;
1349         }
1350 }
1351
1352 #define ENT_ANY ((entity_t*)-1)
1353
1354 /**
1355  * Mark declarations, which are read.  This is used to detect variables, which
1356  * are never read.
1357  * Example:
1358  * x = x + 1;
1359  *   x is not marked as "read", because it is only read to calculate its own new
1360  *   value.
1361  *
1362  * x += y; y += x;
1363  *   x and y are not detected as "not read", because multiple variables are
1364  *   involved.
1365  */
1366 static void mark_vars_read(expression_t *const expr, entity_t *lhs_ent)
1367 {
1368         switch (expr->kind) {
1369                 case EXPR_REFERENCE: {
1370                         entity_t *const entity = expr->reference.entity;
1371                         if (entity->kind != ENTITY_VARIABLE
1372                                         && entity->kind != ENTITY_PARAMETER)
1373                                 return;
1374
1375                         if (lhs_ent != entity && lhs_ent != ENT_ANY) {
1376                                 entity->variable.read = true;
1377                         }
1378                         return;
1379                 }
1380
1381                 case EXPR_CALL:
1382                         // TODO respect pure/const
1383                         mark_vars_read(expr->call.function, NULL);
1384                         for (call_argument_t *arg = expr->call.arguments; arg != NULL; arg = arg->next) {
1385                                 mark_vars_read(arg->expression, NULL);
1386                         }
1387                         return;
1388
1389                 case EXPR_CONDITIONAL:
1390                         // TODO lhs_decl should depend on whether true/false have an effect
1391                         mark_vars_read(expr->conditional.condition, NULL);
1392                         if (expr->conditional.true_expression != NULL)
1393                                 mark_vars_read(expr->conditional.true_expression, lhs_ent);
1394                         mark_vars_read(expr->conditional.false_expression, lhs_ent);
1395                         return;
1396
1397                 case EXPR_SELECT:
1398                         if (lhs_ent == ENT_ANY
1399                                         && !is_type_compound(skip_typeref(expr->base.type)))
1400                                 lhs_ent = NULL;
1401                         mark_vars_read(expr->select.compound, lhs_ent);
1402                         return;
1403
1404                 case EXPR_ARRAY_ACCESS: {
1405                         mark_vars_read(expr->array_access.index, lhs_ent);
1406                         expression_t *const ref = expr->array_access.array_ref;
1407                         if (!is_type_array(skip_typeref(revert_automatic_type_conversion(ref)))) {
1408                                 if (lhs_ent == ENT_ANY)
1409                                         lhs_ent = NULL;
1410                         }
1411                         mark_vars_read(ref, lhs_ent);
1412                         return;
1413                 }
1414
1415                 case EXPR_VA_ARG:
1416                         mark_vars_read(expr->va_arge.ap, lhs_ent);
1417                         return;
1418
1419                 case EXPR_VA_COPY:
1420                         mark_vars_read(expr->va_copye.src, lhs_ent);
1421                         return;
1422
1423                 case EXPR_UNARY_CAST:
1424                         /* Special case: Use void cast to mark a variable as "read" */
1425                         if (is_type_void(skip_typeref(expr->base.type)))
1426                                 lhs_ent = NULL;
1427                         goto unary;
1428
1429
1430                 case EXPR_UNARY_THROW:
1431                         if (expr->unary.value == NULL)
1432                                 return;
1433                         /* FALLTHROUGH */
1434                 case EXPR_UNARY_DEREFERENCE:
1435                 case EXPR_UNARY_DELETE:
1436                 case EXPR_UNARY_DELETE_ARRAY:
1437                         if (lhs_ent == ENT_ANY)
1438                                 lhs_ent = NULL;
1439                         goto unary;
1440
1441                 case EXPR_UNARY_NEGATE:
1442                 case EXPR_UNARY_PLUS:
1443                 case EXPR_UNARY_BITWISE_NEGATE:
1444                 case EXPR_UNARY_NOT:
1445                 case EXPR_UNARY_TAKE_ADDRESS:
1446                 case EXPR_UNARY_POSTFIX_INCREMENT:
1447                 case EXPR_UNARY_POSTFIX_DECREMENT:
1448                 case EXPR_UNARY_PREFIX_INCREMENT:
1449                 case EXPR_UNARY_PREFIX_DECREMENT:
1450                 case EXPR_UNARY_ASSUME:
1451 unary:
1452                         mark_vars_read(expr->unary.value, lhs_ent);
1453                         return;
1454
1455                 case EXPR_BINARY_ADD:
1456                 case EXPR_BINARY_SUB:
1457                 case EXPR_BINARY_MUL:
1458                 case EXPR_BINARY_DIV:
1459                 case EXPR_BINARY_MOD:
1460                 case EXPR_BINARY_EQUAL:
1461                 case EXPR_BINARY_NOTEQUAL:
1462                 case EXPR_BINARY_LESS:
1463                 case EXPR_BINARY_LESSEQUAL:
1464                 case EXPR_BINARY_GREATER:
1465                 case EXPR_BINARY_GREATEREQUAL:
1466                 case EXPR_BINARY_BITWISE_AND:
1467                 case EXPR_BINARY_BITWISE_OR:
1468                 case EXPR_BINARY_BITWISE_XOR:
1469                 case EXPR_BINARY_LOGICAL_AND:
1470                 case EXPR_BINARY_LOGICAL_OR:
1471                 case EXPR_BINARY_SHIFTLEFT:
1472                 case EXPR_BINARY_SHIFTRIGHT:
1473                 case EXPR_BINARY_COMMA:
1474                 case EXPR_BINARY_ISGREATER:
1475                 case EXPR_BINARY_ISGREATEREQUAL:
1476                 case EXPR_BINARY_ISLESS:
1477                 case EXPR_BINARY_ISLESSEQUAL:
1478                 case EXPR_BINARY_ISLESSGREATER:
1479                 case EXPR_BINARY_ISUNORDERED:
1480                         mark_vars_read(expr->binary.left,  lhs_ent);
1481                         mark_vars_read(expr->binary.right, lhs_ent);
1482                         return;
1483
1484                 case EXPR_BINARY_ASSIGN:
1485                 case EXPR_BINARY_MUL_ASSIGN:
1486                 case EXPR_BINARY_DIV_ASSIGN:
1487                 case EXPR_BINARY_MOD_ASSIGN:
1488                 case EXPR_BINARY_ADD_ASSIGN:
1489                 case EXPR_BINARY_SUB_ASSIGN:
1490                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:
1491                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:
1492                 case EXPR_BINARY_BITWISE_AND_ASSIGN:
1493                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:
1494                 case EXPR_BINARY_BITWISE_OR_ASSIGN: {
1495                         if (lhs_ent == ENT_ANY)
1496                                 lhs_ent = NULL;
1497                         lhs_ent = determine_lhs_ent(expr->binary.left, lhs_ent);
1498                         mark_vars_read(expr->binary.right, lhs_ent);
1499                         return;
1500                 }
1501
1502                 case EXPR_VA_START:
1503                         determine_lhs_ent(expr->va_starte.ap, lhs_ent);
1504                         return;
1505
1506                 case EXPR_LITERAL_CASES:
1507                 case EXPR_LITERAL_CHARACTER:
1508                 case EXPR_ERROR:
1509                 case EXPR_STRING_LITERAL:
1510                 case EXPR_COMPOUND_LITERAL: // TODO init?
1511                 case EXPR_SIZEOF:
1512                 case EXPR_CLASSIFY_TYPE:
1513                 case EXPR_ALIGNOF:
1514                 case EXPR_FUNCNAME:
1515                 case EXPR_BUILTIN_CONSTANT_P:
1516                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
1517                 case EXPR_OFFSETOF:
1518                 case EXPR_STATEMENT: // TODO
1519                 case EXPR_LABEL_ADDRESS:
1520                 case EXPR_ENUM_CONSTANT:
1521                         return;
1522         }
1523
1524         panic("unhandled expression");
1525 }
1526
1527 static designator_t *parse_designation(void)
1528 {
1529         designator_t  *result = NULL;
1530         designator_t **anchor = &result;
1531
1532         for (;;) {
1533                 designator_t *designator;
1534                 switch (token.kind) {
1535                 case '[':
1536                         designator      = allocate_ast_zero(sizeof(designator[0]));
1537                         designator->pos = *HERE;
1538                         eat('[');
1539                         add_anchor_token(']');
1540                         designator->array_index = parse_constant_expression();
1541                         rem_anchor_token(']');
1542                         expect(']');
1543                         break;
1544                 case '.':
1545                         designator      = allocate_ast_zero(sizeof(designator[0]));
1546                         designator->pos = *HERE;
1547                         eat('.');
1548                         designator->symbol = expect_identifier("while parsing designator", NULL);
1549                         if (!designator->symbol)
1550                                 return NULL;
1551                         break;
1552                 default:
1553                         expect('=');
1554                         return result;
1555                 }
1556
1557                 assert(designator != NULL);
1558                 *anchor = designator;
1559                 anchor  = &designator->next;
1560         }
1561 }
1562
1563 /**
1564  * Build an initializer from a given expression.
1565  */
1566 static initializer_t *initializer_from_expression(type_t *orig_type,
1567                                                   expression_t *expression)
1568 {
1569         /* TODO check that expression is a constant expression */
1570
1571         type_t *const type = skip_typeref(orig_type);
1572
1573         /* §6.7.8.14/15 char array may be initialized by string literals */
1574         if (expression->kind == EXPR_STRING_LITERAL && is_type_array(type)) {
1575                 array_type_t *const array_type   = &type->array;
1576                 type_t       *const element_type = skip_typeref(array_type->element_type);
1577                 switch (expression->string_literal.value.encoding) {
1578                 case STRING_ENCODING_CHAR:
1579                 case STRING_ENCODING_UTF8: {
1580                         if (is_type_atomic(element_type, ATOMIC_TYPE_CHAR)  ||
1581                             is_type_atomic(element_type, ATOMIC_TYPE_SCHAR) ||
1582                             is_type_atomic(element_type, ATOMIC_TYPE_UCHAR)) {
1583                                 goto make_string_init;
1584                         }
1585                         break;
1586                 }
1587
1588                 case STRING_ENCODING_CHAR16:
1589                 case STRING_ENCODING_CHAR32:
1590                 case STRING_ENCODING_WIDE: {
1591                         assert(is_type_pointer(expression->base.type));
1592                         type_t *const init_type = get_unqualified_type(expression->base.type->pointer.points_to);
1593                         if (types_compatible(get_unqualified_type(element_type), init_type)) {
1594 make_string_init:;
1595                                 initializer_t *const init = allocate_initializer_zero(INITIALIZER_STRING);
1596                                 init->value.value = expression;
1597                                 return init;
1598                         }
1599                         break;
1600                 }
1601                 }
1602         }
1603
1604         assign_error_t error = semantic_assign(type, expression);
1605         if (error == ASSIGN_ERROR_INCOMPATIBLE)
1606                 return NULL;
1607         report_assign_error(error, type, expression, "initializer",
1608                             &expression->base.pos);
1609
1610         initializer_t *const result = allocate_initializer_zero(INITIALIZER_VALUE);
1611         result->value.value = create_implicit_cast(expression, type);
1612
1613         return result;
1614 }
1615
1616 /**
1617  * Parses an scalar initializer.
1618  *
1619  * §6.7.8.11; eat {} without warning
1620  */
1621 static initializer_t *parse_scalar_initializer(type_t *type,
1622                                                bool must_be_constant)
1623 {
1624         /* there might be extra {} hierarchies */
1625         int braces = 0;
1626         if (token.kind == '{') {
1627                 warningf(WARN_OTHER, HERE, "extra curly braces around scalar initializer");
1628                 do {
1629                         eat('{');
1630                         ++braces;
1631                 } while (token.kind == '{');
1632         }
1633
1634         expression_t *expression = parse_assignment_expression();
1635         mark_vars_read(expression, NULL);
1636         if (must_be_constant && !is_linker_constant(expression)) {
1637                 errorf(&expression->base.pos,
1638                        "initialisation expression '%E' is not constant",
1639                        expression);
1640         }
1641
1642         initializer_t *initializer = initializer_from_expression(type, expression);
1643
1644         if (initializer == NULL) {
1645                 errorf(&expression->base.pos,
1646                        "expression '%E' (type '%T') doesn't match expected type '%T'",
1647                        expression, expression->base.type, type);
1648                 /* TODO */
1649                 return NULL;
1650         }
1651
1652         bool additional_warning_displayed = false;
1653         while (braces > 0) {
1654                 accept(',');
1655                 if (token.kind != '}') {
1656                         if (!additional_warning_displayed) {
1657                                 warningf(WARN_OTHER, HERE, "additional elements in scalar initializer");
1658                                 additional_warning_displayed = true;
1659                         }
1660                 }
1661                 eat_block();
1662                 braces--;
1663         }
1664
1665         return initializer;
1666 }
1667
1668 /**
1669  * An entry in the type path.
1670  */
1671 typedef struct type_path_entry_t type_path_entry_t;
1672 struct type_path_entry_t {
1673         type_t *type;       /**< the upper top type. restored to path->top_tye if this entry is popped. */
1674         union {
1675                 size_t         index;          /**< For array types: the current index. */
1676                 declaration_t *compound_entry; /**< For compound types: the current declaration. */
1677         } v;
1678 };
1679
1680 /**
1681  * A type path expression a position inside compound or array types.
1682  */
1683 typedef struct type_path_t type_path_t;
1684 struct type_path_t {
1685         type_path_entry_t *path;         /**< An flexible array containing the current path. */
1686         type_t            *top_type;     /**< type of the element the path points */
1687         size_t             max_index;    /**< largest index in outermost array */
1688 };
1689
1690 /**
1691  * Prints a type path for debugging.
1692  */
1693 static __attribute__((unused)) void debug_print_type_path(
1694                 const type_path_t *path)
1695 {
1696         size_t len = ARR_LEN(path->path);
1697
1698         for (size_t i = 0; i < len; ++i) {
1699                 const type_path_entry_t *entry = & path->path[i];
1700
1701                 type_t *type = skip_typeref(entry->type);
1702                 if (is_type_compound(type)) {
1703                         /* in gcc mode structs can have no members */
1704                         if (entry->v.compound_entry == NULL) {
1705                                 assert(i == len-1);
1706                                 continue;
1707                         }
1708                         fprintf(stderr, ".%s",
1709                                 entry->v.compound_entry->base.symbol->string);
1710                 } else if (is_type_array(type)) {
1711                         fprintf(stderr, "[%u]", (unsigned) entry->v.index);
1712                 } else {
1713                         fprintf(stderr, "-INVALID-");
1714                 }
1715         }
1716         if (path->top_type != NULL) {
1717                 fprintf(stderr, "  (");
1718                 print_type(path->top_type);
1719                 fprintf(stderr, ")");
1720         }
1721 }
1722
1723 /**
1724  * Return the top type path entry, i.e. in a path
1725  * (type).a.b returns the b.
1726  */
1727 static type_path_entry_t *get_type_path_top(const type_path_t *path)
1728 {
1729         size_t len = ARR_LEN(path->path);
1730         assert(len > 0);
1731         return &path->path[len-1];
1732 }
1733
1734 /**
1735  * Enlarge the type path by an (empty) element.
1736  */
1737 static type_path_entry_t *append_to_type_path(type_path_t *path)
1738 {
1739         size_t len = ARR_LEN(path->path);
1740         ARR_RESIZE(type_path_entry_t, path->path, len+1);
1741
1742         type_path_entry_t *result = & path->path[len];
1743         memset(result, 0, sizeof(result[0]));
1744         return result;
1745 }
1746
1747 /**
1748  * Descending into a sub-type. Enter the scope of the current top_type.
1749  */
1750 static void descend_into_subtype(type_path_t *path)
1751 {
1752         type_t *orig_top_type = path->top_type;
1753         type_t *top_type      = skip_typeref(orig_top_type);
1754
1755         type_path_entry_t *top = append_to_type_path(path);
1756         top->type              = top_type;
1757
1758         if (is_type_compound(top_type)) {
1759                 compound_t *const compound = top_type->compound.compound;
1760                 entity_t   *const entry    = skip_unnamed_bitfields(compound->members.entities);
1761
1762                 if (entry != NULL) {
1763                         top->v.compound_entry = &entry->declaration;
1764                         path->top_type = entry->declaration.type;
1765                 } else {
1766                         path->top_type = NULL;
1767                 }
1768         } else if (is_type_array(top_type)) {
1769                 top->v.index   = 0;
1770                 path->top_type = top_type->array.element_type;
1771         } else {
1772                 assert(!is_type_valid(top_type));
1773         }
1774 }
1775
1776 /**
1777  * Pop an entry from the given type path, i.e. returning from
1778  * (type).a.b to (type).a
1779  */
1780 static void ascend_from_subtype(type_path_t *path)
1781 {
1782         type_path_entry_t *top = get_type_path_top(path);
1783
1784         path->top_type = top->type;
1785
1786         size_t len = ARR_LEN(path->path);
1787         ARR_RESIZE(type_path_entry_t, path->path, len-1);
1788 }
1789
1790 /**
1791  * Pop entries from the given type path until the given
1792  * path level is reached.
1793  */
1794 static void ascend_to(type_path_t *path, size_t top_path_level)
1795 {
1796         size_t len = ARR_LEN(path->path);
1797
1798         while (len > top_path_level) {
1799                 ascend_from_subtype(path);
1800                 len = ARR_LEN(path->path);
1801         }
1802 }
1803
1804 static bool walk_designator(type_path_t *path, const designator_t *designator,
1805                             bool used_in_offsetof)
1806 {
1807         for (; designator != NULL; designator = designator->next) {
1808                 type_path_entry_t *top       = get_type_path_top(path);
1809                 type_t            *orig_type = top->type;
1810
1811                 type_t *type = skip_typeref(orig_type);
1812
1813                 if (designator->symbol != NULL) {
1814                         symbol_t *symbol = designator->symbol;
1815                         if (!is_type_compound(type)) {
1816                                 if (is_type_valid(type)) {
1817                                         errorf(&designator->pos,
1818                                                "'.%Y' designator used for non-compound type '%T'",
1819                                                symbol, orig_type);
1820                                 }
1821
1822                                 top->type             = type_error_type;
1823                                 top->v.compound_entry = NULL;
1824                                 orig_type             = type_error_type;
1825                         } else {
1826                                 compound_t *compound = type->compound.compound;
1827                                 entity_t   *iter     = compound->members.entities;
1828                                 for (; iter != NULL; iter = iter->base.next) {
1829                                         if (iter->base.symbol == symbol) {
1830                                                 break;
1831                                         }
1832                                 }
1833                                 if (iter == NULL) {
1834                                         errorf(&designator->pos,
1835                                                "'%T' has no member named '%Y'", orig_type, symbol);
1836                                         return false;
1837                                 }
1838                                 assert(iter->kind == ENTITY_COMPOUND_MEMBER);
1839                                 if (used_in_offsetof && iter->compound_member.bitfield) {
1840                                         errorf(&designator->pos,
1841                                                    "offsetof designator '%Y' must not specify bitfield",
1842                                                    symbol);
1843                                         return false;
1844                                 }
1845
1846                                 top->type             = orig_type;
1847                                 top->v.compound_entry = &iter->declaration;
1848                                 orig_type             = iter->declaration.type;
1849                         }
1850                 } else {
1851                         expression_t *array_index = designator->array_index;
1852                         if (is_constant_expression(array_index) != EXPR_CLASS_CONSTANT)
1853                                 return true;
1854
1855                         if (!is_type_array(type)) {
1856                                 if (is_type_valid(type)) {
1857                                         errorf(&designator->pos,
1858                                                "[%E] designator used for non-array type '%T'",
1859                                                array_index, orig_type);
1860                                 }
1861                                 return false;
1862                         }
1863
1864                         long index = fold_constant_to_int(array_index);
1865                         if (!used_in_offsetof) {
1866                                 if (index < 0) {
1867                                         errorf(&designator->pos,
1868                                                "array index [%E] must be positive", array_index);
1869                                 } else if (type->array.size_constant) {
1870                                         long array_size = type->array.size;
1871                                         if (index >= array_size) {
1872                                                 errorf(&designator->pos,
1873                                                        "designator [%E] (%d) exceeds array size %d",
1874                                                        array_index, index, array_size);
1875                                         }
1876                                 }
1877                         }
1878
1879                         top->type    = orig_type;
1880                         top->v.index = (size_t) index;
1881                         orig_type    = type->array.element_type;
1882                 }
1883                 path->top_type = orig_type;
1884
1885                 if (designator->next != NULL) {
1886                         descend_into_subtype(path);
1887                 }
1888         }
1889         return true;
1890 }
1891
1892 static void advance_current_object(type_path_t *path, size_t top_path_level)
1893 {
1894         type_path_entry_t *top = get_type_path_top(path);
1895
1896         type_t *type = skip_typeref(top->type);
1897         if (is_type_union(type)) {
1898                 /* in unions only the first element is initialized */
1899                 top->v.compound_entry = NULL;
1900         } else if (is_type_struct(type)) {
1901                 declaration_t *entry = top->v.compound_entry;
1902
1903                 entity_t *const next_entity = skip_unnamed_bitfields(entry->base.next);
1904                 if (next_entity != NULL) {
1905                         assert(is_declaration(next_entity));
1906                         entry = &next_entity->declaration;
1907                 } else {
1908                         entry = NULL;
1909                 }
1910
1911                 top->v.compound_entry = entry;
1912                 if (entry != NULL) {
1913                         path->top_type = entry->type;
1914                         return;
1915                 }
1916         } else if (is_type_array(type)) {
1917                 assert(is_type_array(type));
1918
1919                 top->v.index++;
1920
1921                 if (!type->array.size_constant || top->v.index < type->array.size) {
1922                         return;
1923                 }
1924         } else {
1925                 assert(!is_type_valid(type));
1926                 return;
1927         }
1928
1929         /* we're past the last member of the current sub-aggregate, try if we
1930          * can ascend in the type hierarchy and continue with another subobject */
1931         size_t len = ARR_LEN(path->path);
1932
1933         if (len > top_path_level) {
1934                 ascend_from_subtype(path);
1935                 advance_current_object(path, top_path_level);
1936         } else {
1937                 path->top_type = NULL;
1938         }
1939 }
1940
1941 /**
1942  * skip any {...} blocks until a closing bracket is reached.
1943  */
1944 static void skip_initializers(void)
1945 {
1946         accept('{');
1947
1948         while (token.kind != '}') {
1949                 if (token.kind == T_EOF)
1950                         return;
1951                 if (token.kind == '{') {
1952                         eat_block();
1953                         continue;
1954                 }
1955                 next_token();
1956         }
1957 }
1958
1959 static initializer_t *create_empty_initializer(void)
1960 {
1961         static initializer_t empty_initializer
1962                 = { .list = { { INITIALIZER_LIST }, 0 } };
1963         return &empty_initializer;
1964 }
1965
1966 /**
1967  * Parse a part of an initialiser for a struct or union,
1968  */
1969 static initializer_t *parse_sub_initializer(type_path_t *path,
1970                 type_t *outer_type, size_t top_path_level,
1971                 parse_initializer_env_t *env)
1972 {
1973         if (token.kind == '}') {
1974                 /* empty initializer */
1975                 return create_empty_initializer();
1976         }
1977
1978         initializer_t *result = NULL;
1979
1980         type_t *orig_type = path->top_type;
1981         type_t *type      = NULL;
1982
1983         if (orig_type == NULL) {
1984                 /* We are initializing an empty compound. */
1985         } else {
1986                 type = skip_typeref(orig_type);
1987         }
1988
1989         initializer_t **initializers = NEW_ARR_F(initializer_t*, 0);
1990
1991         while (true) {
1992                 designator_t *designator = NULL;
1993                 if (token.kind == '.' || token.kind == '[') {
1994                         designator = parse_designation();
1995                         goto finish_designator;
1996                 } else if (token.kind == T_IDENTIFIER && look_ahead(1)->kind == ':') {
1997                         /* GNU-style designator ("identifier: value") */
1998                         designator         = allocate_ast_zero(sizeof(designator[0]));
1999                         designator->pos    = *HERE;
2000                         designator->symbol = token.base.symbol;
2001                         eat(T_IDENTIFIER);
2002                         eat(':');
2003
2004 finish_designator:
2005                         /* reset path to toplevel, evaluate designator from there */
2006                         ascend_to(path, top_path_level);
2007                         if (!walk_designator(path, designator, false)) {
2008                                 /* can't continue after designation error */
2009                                 goto end_error;
2010                         }
2011
2012                         initializer_t *designator_initializer
2013                                 = allocate_initializer_zero(INITIALIZER_DESIGNATOR);
2014                         designator_initializer->designator.designator = designator;
2015                         ARR_APP1(initializer_t*, initializers, designator_initializer);
2016
2017                         orig_type = path->top_type;
2018                         type      = orig_type != NULL ? skip_typeref(orig_type) : NULL;
2019                 }
2020
2021                 initializer_t *sub;
2022
2023                 if (token.kind == '{') {
2024                         if (type != NULL && is_type_scalar(type)) {
2025                                 sub = parse_scalar_initializer(type, env->must_be_constant);
2026                         } else {
2027                                 if (type == NULL) {
2028                                         if (env->entity != NULL) {
2029                                                 errorf(HERE, "extra brace group at end of initializer for '%N'", env->entity);
2030                                         } else {
2031                                                 errorf(HERE, "extra brace group at end of initializer");
2032                                         }
2033                                         eat('{');
2034                                 } else {
2035                                         eat('{');
2036                                         descend_into_subtype(path);
2037                                 }
2038
2039                                 add_anchor_token('}');
2040                                 sub = parse_sub_initializer(path, orig_type, top_path_level+1,
2041                                                             env);
2042                                 rem_anchor_token('}');
2043
2044                                 expect('}');
2045
2046                                 if (!type)
2047                                         goto error_parse_next;
2048
2049                                 ascend_from_subtype(path);
2050                         }
2051                 } else {
2052                         /* must be an expression */
2053                         expression_t *expression = parse_assignment_expression();
2054                         mark_vars_read(expression, NULL);
2055
2056                         if (env->must_be_constant && !is_linker_constant(expression)) {
2057                                 errorf(&expression->base.pos,
2058                                        "Initialisation expression '%E' is not constant",
2059                                        expression);
2060                         }
2061
2062                         if (type == NULL) {
2063                                 /* we are already outside, ... */
2064                                 if (outer_type == NULL)
2065                                         goto error_parse_next;
2066                                 type_t *const outer_type_skip = skip_typeref(outer_type);
2067                                 if (is_type_compound(outer_type_skip) &&
2068                                                 !outer_type_skip->compound.compound->complete) {
2069                                         goto error_parse_next;
2070                                 }
2071
2072                                 position_t const* const pos = &expression->base.pos;
2073                                 if (env->entity != NULL) {
2074                                         warningf(WARN_OTHER, pos, "excess elements in initializer for '%N'", env->entity);
2075                                 } else {
2076                                         warningf(WARN_OTHER, pos, "excess elements in initializer");
2077                                 }
2078                                 goto error_parse_next;
2079                         }
2080
2081                         /* handle { "string" } special case */
2082                         if (expression->kind == EXPR_STRING_LITERAL && outer_type != NULL) {
2083                                 result = initializer_from_expression(outer_type, expression);
2084                                 if (result != NULL) {
2085                                         accept(',');
2086                                         if (token.kind != '}') {
2087                                                 warningf(WARN_OTHER, HERE, "excessive elements in initializer for type '%T'", outer_type);
2088                                         }
2089                                         /* TODO: eat , ... */
2090                                         goto out;
2091                                 }
2092                         }
2093
2094                         /* descend into subtypes until expression matches type */
2095                         while (true) {
2096                                 orig_type = path->top_type;
2097                                 type      = skip_typeref(orig_type);
2098
2099                                 sub = initializer_from_expression(orig_type, expression);
2100                                 if (sub != NULL) {
2101                                         break;
2102                                 }
2103                                 if (!is_type_valid(type)) {
2104                                         goto end_error;
2105                                 }
2106                                 if (is_type_scalar(type)) {
2107                                         errorf(&expression->base.pos,
2108                                                         "expression '%E' doesn't match expected type '%T'",
2109                                                         expression, orig_type);
2110                                         goto end_error;
2111                                 }
2112
2113                                 descend_into_subtype(path);
2114                         }
2115                 }
2116
2117                 /* update largest index of top array */
2118                 const type_path_entry_t *first      = &path->path[0];
2119                 type_t                  *first_type = first->type;
2120                 first_type                          = skip_typeref(first_type);
2121                 if (is_type_array(first_type)) {
2122                         size_t index = first->v.index;
2123                         if (index > path->max_index)
2124                                 path->max_index = index;
2125                 }
2126
2127                 /* append to initializers list */
2128                 ARR_APP1(initializer_t*, initializers, sub);
2129
2130 error_parse_next:
2131                 if (!accept(','))
2132                         break;
2133                 if (token.kind == '}') {
2134                         break;
2135                 }
2136
2137                 if (type != NULL) {
2138                         /* advance to the next declaration if we are not at the end */
2139                         advance_current_object(path, top_path_level);
2140                         orig_type = path->top_type;
2141                         if (orig_type != NULL)
2142                                 type = skip_typeref(orig_type);
2143                         else
2144                                 type = NULL;
2145                 }
2146         }
2147
2148         size_t len  = ARR_LEN(initializers);
2149         size_t size = sizeof(initializer_list_t) + len * sizeof(initializers[0]);
2150         result = allocate_ast_zero(size);
2151         result->kind     = INITIALIZER_LIST;
2152         result->list.len = len;
2153         memcpy(&result->list.initializers, initializers,
2154                len * sizeof(initializers[0]));
2155         goto out;
2156
2157 end_error:
2158         skip_initializers();
2159 out:
2160         DEL_ARR_F(initializers);
2161         ascend_to(path, top_path_level+1);
2162         return result;
2163 }
2164
2165 static expression_t *make_size_literal(size_t value)
2166 {
2167         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_INTEGER);
2168         literal->base.type    = type_size_t;
2169
2170         char buf[128];
2171         snprintf(buf, sizeof(buf), "%u", (unsigned) value);
2172         literal->literal.value = make_string(buf);
2173
2174         return literal;
2175 }
2176
2177 /**
2178  * Parses an initializer. Parsers either a compound literal
2179  * (env->declaration == NULL) or an initializer of a declaration.
2180  */
2181 static initializer_t *parse_initializer(parse_initializer_env_t *env)
2182 {
2183         type_t        *type      = skip_typeref(env->type);
2184         size_t         max_index = 0;
2185         initializer_t *result;
2186
2187         if (is_type_scalar(type)) {
2188                 result = parse_scalar_initializer(type, env->must_be_constant);
2189         } else if (token.kind == '{') {
2190                 eat('{');
2191
2192                 type_path_t path;
2193                 memset(&path, 0, sizeof(path));
2194                 path.top_type = env->type;
2195                 path.path     = NEW_ARR_F(type_path_entry_t, 0);
2196
2197                 descend_into_subtype(&path);
2198
2199                 add_anchor_token('}');
2200                 result = parse_sub_initializer(&path, env->type, 1, env);
2201                 rem_anchor_token('}');
2202
2203                 max_index = path.max_index;
2204                 DEL_ARR_F(path.path);
2205
2206                 expect('}');
2207         } else {
2208                 /* parse_scalar_initializer() also works in this case: we simply
2209                  * have an expression without {} around it */
2210                 result = parse_scalar_initializer(type, env->must_be_constant);
2211         }
2212
2213         /* §6.7.8:22 array initializers for arrays with unknown size determine
2214          * the array type size */
2215         if (is_type_array(type) && type->array.size_expression == NULL
2216                         && result != NULL) {
2217                 size_t size;
2218                 switch (result->kind) {
2219                 case INITIALIZER_LIST:
2220                         assert(max_index != 0xdeadbeaf);
2221                         size = max_index + 1;
2222                         break;
2223
2224                 case INITIALIZER_STRING: {
2225                         size = get_string_len(&get_init_string(result)->value) + 1;
2226                         break;
2227                 }
2228
2229                 case INITIALIZER_DESIGNATOR:
2230                 case INITIALIZER_VALUE:
2231                         /* can happen for parse errors */
2232                         size = 0;
2233                         break;
2234
2235                 default:
2236                         internal_errorf(HERE, "invalid initializer type");
2237                 }
2238
2239                 type_t *new_type = duplicate_type(type);
2240
2241                 new_type->array.size_expression   = make_size_literal(size);
2242                 new_type->array.size_constant     = true;
2243                 new_type->array.has_implicit_size = true;
2244                 new_type->array.size              = size;
2245                 env->type = new_type;
2246         }
2247
2248         return result;
2249 }
2250
2251 static void append_entity(scope_t *scope, entity_t *entity)
2252 {
2253         if (scope->last_entity != NULL) {
2254                 scope->last_entity->base.next = entity;
2255         } else {
2256                 scope->entities = entity;
2257         }
2258         entity->base.parent_entity = current_entity;
2259         scope->last_entity         = entity;
2260 }
2261
2262
2263 static compound_t *parse_compound_type_specifier(bool is_struct)
2264 {
2265         position_t const pos = *HERE;
2266         eat(is_struct ? T_struct : T_union);
2267
2268         symbol_t    *symbol     = NULL;
2269         entity_t    *entity     = NULL;
2270         attribute_t *attributes = NULL;
2271
2272         if (token.kind == T___attribute__) {
2273                 attributes = parse_attributes(NULL);
2274         }
2275
2276         entity_kind_tag_t const kind = is_struct ? ENTITY_STRUCT : ENTITY_UNION;
2277         if (token.kind == T_IDENTIFIER) {
2278                 /* the compound has a name, check if we have seen it already */
2279                 symbol = token.base.symbol;
2280                 entity = get_tag(symbol, kind);
2281                 eat(T_IDENTIFIER);
2282
2283                 if (entity != NULL) {
2284                         if (entity->base.parent_scope != current_scope &&
2285                             (token.kind == '{' || token.kind == ';')) {
2286                                 /* we're in an inner scope and have a definition. Shadow
2287                                  * existing definition in outer scope */
2288                                 entity = NULL;
2289                         } else if (entity->compound.complete && token.kind == '{') {
2290                                 position_t const *const ppos = &entity->base.pos;
2291                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2292                                 /* clear members in the hope to avoid further errors */
2293                                 entity->compound.members.entities = NULL;
2294                         }
2295                 }
2296         } else if (token.kind != '{') {
2297                 char const *const msg =
2298                         is_struct ? "while parsing struct type specifier" :
2299                                     "while parsing union type specifier";
2300                 parse_error_expected(msg, T_IDENTIFIER, '{', NULL);
2301
2302                 return NULL;
2303         }
2304
2305         if (entity == NULL) {
2306                 entity = allocate_entity_zero(kind, NAMESPACE_TAG, symbol, &pos);
2307                 entity->compound.alignment = 1;
2308                 entity->base.parent_scope  = current_scope;
2309                 if (symbol != NULL) {
2310                         environment_push(entity);
2311                 }
2312                 append_entity(current_scope, entity);
2313         }
2314
2315         if (token.kind == '{') {
2316                 parse_compound_type_entries(&entity->compound);
2317
2318                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2319                 if (symbol == NULL) {
2320                         assert(anonymous_entity == NULL);
2321                         anonymous_entity = entity;
2322                 }
2323         }
2324
2325         if (attributes != NULL) {
2326                 entity->compound.attributes = attributes;
2327                 handle_entity_attributes(attributes, entity);
2328         }
2329
2330         return &entity->compound;
2331 }
2332
2333 static void parse_enum_entries(type_t *const enum_type)
2334 {
2335         eat('{');
2336
2337         if (token.kind == '}') {
2338                 errorf(HERE, "empty enum not allowed");
2339                 eat('}');
2340                 return;
2341         }
2342
2343         add_anchor_token('}');
2344         add_anchor_token(',');
2345         do {
2346                 add_anchor_token('=');
2347                 position_t pos;
2348                 symbol_t *const symbol = expect_identifier("while parsing enum entry", &pos);
2349                 entity_t *const entity = allocate_entity_zero(ENTITY_ENUM_VALUE, NAMESPACE_NORMAL, symbol, &pos);
2350                 entity->enum_value.enum_type = enum_type;
2351                 rem_anchor_token('=');
2352
2353                 if (accept('=')) {
2354                         expression_t *value = parse_constant_expression();
2355
2356                         value = create_implicit_cast(value, enum_type);
2357                         entity->enum_value.value = value;
2358
2359                         /* TODO semantic */
2360                 }
2361
2362                 record_entity(entity, false);
2363         } while (accept(',') && token.kind != '}');
2364         rem_anchor_token(',');
2365         rem_anchor_token('}');
2366
2367         expect('}');
2368 }
2369
2370 static type_t *parse_enum_specifier(void)
2371 {
2372         position_t const pos = *HERE;
2373         entity_t        *entity;
2374         symbol_t        *symbol;
2375
2376         eat(T_enum);
2377         switch (token.kind) {
2378                 case T_IDENTIFIER:
2379                         symbol = token.base.symbol;
2380                         entity = get_tag(symbol, ENTITY_ENUM);
2381                         eat(T_IDENTIFIER);
2382
2383                         if (entity != NULL) {
2384                                 if (entity->base.parent_scope != current_scope &&
2385                                                 (token.kind == '{' || token.kind == ';')) {
2386                                         /* we're in an inner scope and have a definition. Shadow
2387                                          * existing definition in outer scope */
2388                                         entity = NULL;
2389                                 } else if (entity->enume.complete && token.kind == '{') {
2390                                         position_t const *const ppos = &entity->base.pos;
2391                                         errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
2392                                 }
2393                         }
2394                         break;
2395
2396                 case '{':
2397                         entity = NULL;
2398                         symbol = NULL;
2399                         break;
2400
2401                 default:
2402                         parse_error_expected("while parsing enum type specifier",
2403                                         T_IDENTIFIER, '{', NULL);
2404                         return NULL;
2405         }
2406
2407         if (entity == NULL) {
2408                 entity = allocate_entity_zero(ENTITY_ENUM, NAMESPACE_TAG, symbol, &pos);
2409                 entity->base.parent_scope = current_scope;
2410         }
2411
2412         type_t *const type     = allocate_type_zero(TYPE_ENUM);
2413         type->enumt.enume      = &entity->enume;
2414         type->enumt.base.akind = ATOMIC_TYPE_INT;
2415
2416         if (token.kind == '{') {
2417                 if (symbol != NULL) {
2418                         environment_push(entity);
2419                 }
2420                 append_entity(current_scope, entity);
2421                 entity->enume.complete = true;
2422
2423                 parse_enum_entries(type);
2424                 parse_attributes(NULL);
2425
2426                 /* ISO/IEC 14882:1998(E) §7.1.3:5 */
2427                 if (symbol == NULL) {
2428                         assert(anonymous_entity == NULL);
2429                         anonymous_entity = entity;
2430                 }
2431         } else if (!entity->enume.complete && !(c_mode & _GNUC)) {
2432                 errorf(HERE, "'%T' used before definition (incomplete enums are a GNU extension)", type);
2433         }
2434
2435         return type;
2436 }
2437
2438 /**
2439  * if a symbol is a typedef to another type, return true
2440  */
2441 static bool is_typedef_symbol(symbol_t *symbol)
2442 {
2443         const entity_t *const entity = get_entity(symbol, NAMESPACE_NORMAL);
2444         return entity != NULL && entity->kind == ENTITY_TYPEDEF;
2445 }
2446
2447 static type_t *parse_typeof(void)
2448 {
2449         eat(T___typeof__);
2450
2451         type_t *type;
2452
2453         add_anchor_token(')');
2454         expect('(');
2455
2456         expression_t *expression  = NULL;
2457
2458         switch (token.kind) {
2459         case T_IDENTIFIER:
2460                 if (is_typedef_symbol(token.base.symbol)) {
2461         DECLARATION_START
2462                         type = parse_typename();
2463                 } else {
2464         default:
2465                         expression = parse_expression();
2466                         type       = revert_automatic_type_conversion(expression);
2467                 }
2468                 break;
2469         }
2470
2471         rem_anchor_token(')');
2472         expect(')');
2473
2474         type_t *typeof_type              = allocate_type_zero(TYPE_TYPEOF);
2475         typeof_type->typeoft.expression  = expression;
2476         typeof_type->typeoft.typeof_type = type;
2477
2478         return typeof_type;
2479 }
2480
2481 typedef enum specifiers_t {
2482         SPECIFIER_NONE      = 0,
2483         SPECIFIER_SIGNED    = 1 << 0,
2484         SPECIFIER_UNSIGNED  = 1 << 1,
2485         SPECIFIER_LONG      = 1 << 2,
2486         SPECIFIER_INT       = 1 << 3,
2487         SPECIFIER_DOUBLE    = 1 << 4,
2488         SPECIFIER_CHAR      = 1 << 5,
2489         SPECIFIER_WCHAR_T   = 1 << 6,
2490         SPECIFIER_SHORT     = 1 << 7,
2491         SPECIFIER_LONG_LONG = 1 << 8,
2492         SPECIFIER_FLOAT     = 1 << 9,
2493         SPECIFIER_BOOL      = 1 << 10,
2494         SPECIFIER_VOID      = 1 << 11,
2495         SPECIFIER_INT8      = 1 << 12,
2496         SPECIFIER_INT16     = 1 << 13,
2497         SPECIFIER_INT32     = 1 << 14,
2498         SPECIFIER_INT64     = 1 << 15,
2499         SPECIFIER_INT128    = 1 << 16,
2500         SPECIFIER_COMPLEX   = 1 << 17,
2501         SPECIFIER_IMAGINARY = 1 << 18,
2502 } specifiers_t;
2503
2504 static type_t *get_typedef_type(symbol_t *symbol)
2505 {
2506         entity_t *entity = get_entity(symbol, NAMESPACE_NORMAL);
2507         if (entity == NULL || entity->kind != ENTITY_TYPEDEF)
2508                 return NULL;
2509
2510         type_t *type            = allocate_type_zero(TYPE_TYPEDEF);
2511         type->typedeft.typedefe = &entity->typedefe;
2512
2513         return type;
2514 }
2515
2516 static attribute_t *parse_attribute_ms_property(attribute_t *attribute)
2517 {
2518         attribute_property_argument_t *const property = allocate_ast_zero(sizeof(*property));
2519
2520         add_anchor_token(')');
2521         add_anchor_token(',');
2522         expect('(');
2523
2524         do {
2525                 add_anchor_token('=');
2526                 position_t pos;
2527                 symbol_t *const prop_sym = expect_identifier("while parsing property declspec", &pos);
2528                 rem_anchor_token('=');
2529
2530                 symbol_t **prop = NULL;
2531                 if (prop_sym) {
2532                         if (streq(prop_sym->string, "put")) {
2533                                 prop = &property->put_symbol;
2534                         } else if (streq(prop_sym->string, "get")) {
2535                                 prop = &property->get_symbol;
2536                         } else {
2537                                 errorf(&pos, "expected put or get in property declspec, but got '%Y'", prop_sym);
2538                         }
2539                 }
2540
2541                 add_anchor_token(T_IDENTIFIER);
2542                 expect('=');
2543                 rem_anchor_token(T_IDENTIFIER);
2544
2545                 symbol_t *const sym = expect_identifier("while parsing property declspec", NULL);
2546                 if (prop != NULL)
2547                         *prop = sym ? sym : sym_anonymous;
2548         } while (accept(','));
2549         rem_anchor_token(',');
2550         rem_anchor_token(')');
2551
2552         attribute->a.property = property;
2553
2554         expect(')');
2555         return attribute;
2556 }
2557
2558 static attribute_t *parse_microsoft_extended_decl_modifier_single(void)
2559 {
2560         attribute_kind_t kind = ATTRIBUTE_UNKNOWN;
2561         if (accept(T_restrict)) {
2562                 kind = ATTRIBUTE_MS_RESTRICT;
2563         } else if (token.kind == T_IDENTIFIER) {
2564                 char const *const name = token.base.symbol->string;
2565                 for (attribute_kind_t k = ATTRIBUTE_MS_FIRST; k <= ATTRIBUTE_MS_LAST;
2566                      ++k) {
2567                         const char *attribute_name = get_attribute_name(k);
2568                         if (attribute_name != NULL && streq(attribute_name, name)) {
2569                                 kind = k;
2570                                 break;
2571                         }
2572                 }
2573
2574                 if (kind == ATTRIBUTE_UNKNOWN) {
2575                         warningf(WARN_ATTRIBUTE, HERE, "unknown __declspec '%s' ignored", name);
2576                 }
2577         } else {
2578                 parse_error_expected("while parsing __declspec", T_IDENTIFIER, NULL);
2579                 return NULL;
2580         }
2581
2582         attribute_t *attribute = allocate_attribute_zero(kind);
2583         eat(T_IDENTIFIER);
2584
2585         if (kind == ATTRIBUTE_MS_PROPERTY) {
2586                 return parse_attribute_ms_property(attribute);
2587         }
2588
2589         /* parse arguments */
2590         if (accept('('))
2591                 attribute->a.arguments = parse_attribute_arguments();
2592
2593         return attribute;
2594 }
2595
2596 static attribute_t *parse_microsoft_extended_decl_modifier(attribute_t *first)
2597 {
2598         eat(T__declspec);
2599
2600         add_anchor_token(')');
2601         expect('(');
2602         if (token.kind != ')') {
2603                 attribute_t **anchor = &first;
2604                 do {
2605                         while (*anchor != NULL)
2606                                 anchor = &(*anchor)->next;
2607
2608                         attribute_t *attribute
2609                                 = parse_microsoft_extended_decl_modifier_single();
2610                         if (attribute == NULL)
2611                                 break;
2612
2613                         *anchor = attribute;
2614                         anchor  = &attribute->next;
2615                 } while (accept(','));
2616         }
2617         rem_anchor_token(')');
2618         expect(')');
2619         return first;
2620 }
2621
2622 static entity_t *create_error_entity(symbol_t *symbol, entity_kind_tag_t kind)
2623 {
2624         entity_t *const entity = allocate_entity_zero(kind, NAMESPACE_NORMAL, symbol, HERE);
2625         if (is_declaration(entity)) {
2626                 entity->declaration.type     = type_error_type;
2627                 entity->declaration.implicit = true;
2628         } else if (kind == ENTITY_TYPEDEF) {
2629                 entity->typedefe.type    = type_error_type;
2630                 entity->typedefe.builtin = true;
2631         }
2632         if (kind != ENTITY_COMPOUND_MEMBER)
2633                 record_entity(entity, false);
2634         return entity;
2635 }
2636
2637 static void parse_declaration_specifiers(declaration_specifiers_t *specifiers)
2638 {
2639         type_t            *type            = NULL;
2640         type_qualifiers_t  qualifiers      = TYPE_QUALIFIER_NONE;
2641         unsigned           type_specifiers = 0;
2642         bool               newtype         = false;
2643         bool               saw_error       = false;
2644
2645         memset(specifiers, 0, sizeof(*specifiers));
2646         specifiers->pos = *HERE;
2647
2648         while (true) {
2649                 specifiers->attributes = parse_attributes(specifiers->attributes);
2650
2651                 switch (token.kind) {
2652                 /* storage class */
2653 #define MATCH_STORAGE_CLASS(token, class)                                  \
2654                 case token:                                                        \
2655                         if (specifiers->storage_class != STORAGE_CLASS_NONE) {         \
2656                                 errorf(HERE, "multiple storage classes in declaration specifiers"); \
2657                         }                                                              \
2658                         specifiers->storage_class = class;                             \
2659                         if (specifiers->thread_local)                                  \
2660                                 goto check_thread_storage_class;                           \
2661                         eat(token); \
2662                         break;
2663
2664                 MATCH_STORAGE_CLASS(T_typedef,  STORAGE_CLASS_TYPEDEF)
2665                 MATCH_STORAGE_CLASS(T_extern,   STORAGE_CLASS_EXTERN)
2666                 MATCH_STORAGE_CLASS(T_static,   STORAGE_CLASS_STATIC)
2667                 MATCH_STORAGE_CLASS(T_auto,     STORAGE_CLASS_AUTO)
2668                 MATCH_STORAGE_CLASS(T_register, STORAGE_CLASS_REGISTER)
2669
2670                 case T__declspec:
2671                         specifiers->attributes
2672                                 = parse_microsoft_extended_decl_modifier(specifiers->attributes);
2673                         break;
2674
2675                 case T__Thread_local:
2676                         if (specifiers->thread_local) {
2677                                 errorf(HERE, "duplicate %K", &token);
2678                         } else {
2679                                 specifiers->thread_local = true;
2680 check_thread_storage_class:
2681                                 switch (specifiers->storage_class) {
2682                                         case STORAGE_CLASS_EXTERN:
2683                                         case STORAGE_CLASS_NONE:
2684                                         case STORAGE_CLASS_STATIC:
2685                                                 break;
2686
2687                                                 char const* wrong;
2688                                         case STORAGE_CLASS_AUTO:     wrong = "auto";     goto wrong_thread_storage_class;
2689                                         case STORAGE_CLASS_REGISTER: wrong = "register"; goto wrong_thread_storage_class;
2690                                         case STORAGE_CLASS_TYPEDEF:  wrong = "typedef";  goto wrong_thread_storage_class;
2691 wrong_thread_storage_class:
2692                                                 errorf(HERE, "%K used with '%s'", &token, wrong);
2693                                                 break;
2694                                 }
2695                         }
2696                         next_token();
2697                         break;
2698
2699                 /* type qualifiers */
2700 #define MATCH_TYPE_QUALIFIER(token, qualifier)                          \
2701                 case token:                                                     \
2702                         qualifiers |= qualifier;                                    \
2703                         eat(token); \
2704                         break
2705
2706                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
2707                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
2708                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
2709                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
2710                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
2711                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
2712                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
2713                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
2714
2715                 /* type specifiers */
2716 #define MATCH_SPECIFIER(token, specifier, name)                         \
2717                 case token:                                                     \
2718                         if (type_specifiers & specifier) {                           \
2719                                 errorf(HERE, "multiple " name " type specifiers given"); \
2720                         } else {                                                    \
2721                                 type_specifiers |= specifier;                           \
2722                         }                                                           \
2723                         eat(token); \
2724                         break
2725
2726                 MATCH_SPECIFIER(T__Bool,      SPECIFIER_BOOL,      "_Bool");
2727                 MATCH_SPECIFIER(T__Complex,   SPECIFIER_COMPLEX,   "_Complex");
2728                 MATCH_SPECIFIER(T__Imaginary, SPECIFIER_IMAGINARY, "_Imaginary");
2729                 MATCH_SPECIFIER(T__int128,    SPECIFIER_INT128,    "_int128");
2730                 MATCH_SPECIFIER(T__int16,     SPECIFIER_INT16,     "_int16");
2731                 MATCH_SPECIFIER(T__int32,     SPECIFIER_INT32,     "_int32");
2732                 MATCH_SPECIFIER(T__int64,     SPECIFIER_INT64,     "_int64");
2733                 MATCH_SPECIFIER(T__int8,      SPECIFIER_INT8,      "_int8");
2734                 MATCH_SPECIFIER(T_bool,       SPECIFIER_BOOL,      "bool");
2735                 MATCH_SPECIFIER(T_char,       SPECIFIER_CHAR,      "char");
2736                 MATCH_SPECIFIER(T_double,     SPECIFIER_DOUBLE,    "double");
2737                 MATCH_SPECIFIER(T_float,      SPECIFIER_FLOAT,     "float");
2738                 MATCH_SPECIFIER(T_int,        SPECIFIER_INT,       "int");
2739                 MATCH_SPECIFIER(T_short,      SPECIFIER_SHORT,     "short");
2740                 MATCH_SPECIFIER(T_signed,     SPECIFIER_SIGNED,    "signed");
2741                 MATCH_SPECIFIER(T_unsigned,   SPECIFIER_UNSIGNED,  "unsigned");
2742                 MATCH_SPECIFIER(T_void,       SPECIFIER_VOID,      "void");
2743                 MATCH_SPECIFIER(T_wchar_t,    SPECIFIER_WCHAR_T,   "wchar_t");
2744
2745                 case T_inline:
2746                         eat(T_inline);
2747                         specifiers->is_inline = true;
2748                         break;
2749
2750 #if 0
2751                 case T__forceinline:
2752                         eat(T__forceinline);
2753                         specifiers->modifiers |= DM_FORCEINLINE;
2754                         break;
2755 #endif
2756
2757                 case T_long:
2758                         if (type_specifiers & SPECIFIER_LONG_LONG) {
2759                                 errorf(HERE, "too many long type specifiers given");
2760                         } else if (type_specifiers & SPECIFIER_LONG) {
2761                                 type_specifiers |= SPECIFIER_LONG_LONG;
2762                         } else {
2763                                 type_specifiers |= SPECIFIER_LONG;
2764                         }
2765                         eat(T_long);
2766                         break;
2767
2768 #define CHECK_DOUBLE_TYPE() \
2769         (type != NULL ? errorf(HERE, "multiple types in declaration specifiers") : (void)0)
2770
2771                 case T_struct:
2772                         CHECK_DOUBLE_TYPE();
2773                         type = allocate_type_zero(TYPE_COMPOUND_STRUCT);
2774
2775                         type->compound.compound = parse_compound_type_specifier(true);
2776                         break;
2777                 case T_union:
2778                         CHECK_DOUBLE_TYPE();
2779                         type = allocate_type_zero(TYPE_COMPOUND_UNION);
2780                         type->compound.compound = parse_compound_type_specifier(false);
2781                         break;
2782                 case T_enum:
2783                         CHECK_DOUBLE_TYPE();
2784                         type = parse_enum_specifier();
2785                         break;
2786                 case T___typeof__:
2787                         CHECK_DOUBLE_TYPE();
2788                         type = parse_typeof();
2789                         break;
2790                 case T___builtin_va_list:
2791                         CHECK_DOUBLE_TYPE();
2792                         type = duplicate_type(type_valist);
2793                         eat(T___builtin_va_list);
2794                         break;
2795
2796                 case T_IDENTIFIER: {
2797                         /* only parse identifier if we haven't found a type yet */
2798                         if (type != NULL || type_specifiers != 0) {
2799                                 /* Be somewhat resilient to typos like 'unsigned lng* f()' in a
2800                                  * declaration, so it doesn't generate errors about expecting '(' or
2801                                  * '{' later on. */
2802                                 switch (look_ahead(1)->kind) {
2803                                         STORAGE_CLASSES
2804                                         TYPE_SPECIFIERS
2805                                         case T_const:
2806                                         case T_restrict:
2807                                         case T_volatile:
2808                                         case T_inline:
2809                                         case T__forceinline: /* ^ DECLARATION_START except for __attribute__ */
2810                                         case T_IDENTIFIER:
2811                                         case '&':
2812                                         case '*':
2813                                                 errorf(HERE, "discarding stray %K in declaration specifier", &token);
2814                                                 eat(T_IDENTIFIER);
2815                                                 continue;
2816
2817                                         default:
2818                                                 goto finish_specifiers;
2819                                 }
2820                         }
2821
2822                         type_t *const typedef_type = get_typedef_type(token.base.symbol);
2823                         if (typedef_type == NULL) {
2824                                 /* Be somewhat resilient to typos like 'vodi f()' at the beginning of a
2825                                  * declaration, so it doesn't generate 'implicit int' followed by more
2826                                  * errors later on. */
2827                                 token_kind_t const la1_type = (token_kind_t)look_ahead(1)->kind;
2828                                 switch (la1_type) {
2829                                         DECLARATION_START
2830                                         case T_IDENTIFIER:
2831                                         case '&':
2832                                         case '*': {
2833                                                 errorf(HERE, "%K does not name a type", &token);
2834
2835                                                 entity_t *const entity = create_error_entity(token.base.symbol, ENTITY_TYPEDEF);
2836
2837                                                 type = allocate_type_zero(TYPE_TYPEDEF);
2838                                                 type->typedeft.typedefe = &entity->typedefe;
2839
2840                                                 eat(T_IDENTIFIER);
2841                                                 saw_error = true;
2842                                                 continue;
2843                                         }
2844
2845                                         default:
2846                                                 goto finish_specifiers;
2847                                 }
2848                         }
2849
2850                         eat(T_IDENTIFIER);
2851                         type = typedef_type;
2852                         break;
2853                 }
2854
2855                 /* function specifier */
2856                 default:
2857                         goto finish_specifiers;
2858                 }
2859         }
2860
2861 finish_specifiers:
2862         specifiers->attributes = parse_attributes(specifiers->attributes);
2863
2864         if (type == NULL || (saw_error && type_specifiers != 0)) {
2865                 atomic_type_kind_t atomic_type;
2866
2867                 /* match valid basic types */
2868                 switch (type_specifiers) {
2869                 case SPECIFIER_VOID:
2870                         atomic_type = ATOMIC_TYPE_VOID;
2871                         break;
2872                 case SPECIFIER_WCHAR_T:
2873                         atomic_type = ATOMIC_TYPE_WCHAR_T;
2874                         break;
2875                 case SPECIFIER_CHAR:
2876                         atomic_type = ATOMIC_TYPE_CHAR;
2877                         break;
2878                 case SPECIFIER_SIGNED | SPECIFIER_CHAR:
2879                         atomic_type = ATOMIC_TYPE_SCHAR;
2880                         break;
2881                 case SPECIFIER_UNSIGNED | SPECIFIER_CHAR:
2882                         atomic_type = ATOMIC_TYPE_UCHAR;
2883                         break;
2884                 case SPECIFIER_SHORT:
2885                 case SPECIFIER_SIGNED | SPECIFIER_SHORT:
2886                 case SPECIFIER_SHORT | SPECIFIER_INT:
2887                 case SPECIFIER_SIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2888                         atomic_type = ATOMIC_TYPE_SHORT;
2889                         break;
2890                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT:
2891                 case SPECIFIER_UNSIGNED | SPECIFIER_SHORT | SPECIFIER_INT:
2892                         atomic_type = ATOMIC_TYPE_USHORT;
2893                         break;
2894                 case SPECIFIER_INT:
2895                 case SPECIFIER_SIGNED:
2896                 case SPECIFIER_SIGNED | SPECIFIER_INT:
2897                         atomic_type = ATOMIC_TYPE_INT;
2898                         break;
2899                 case SPECIFIER_UNSIGNED:
2900                 case SPECIFIER_UNSIGNED | SPECIFIER_INT:
2901                         atomic_type = ATOMIC_TYPE_UINT;
2902                         break;
2903                 case SPECIFIER_LONG:
2904                 case SPECIFIER_SIGNED | SPECIFIER_LONG:
2905                 case SPECIFIER_LONG | SPECIFIER_INT:
2906                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2907                         atomic_type = ATOMIC_TYPE_LONG;
2908                         break;
2909                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:
2910                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_INT:
2911                         atomic_type = ATOMIC_TYPE_ULONG;
2912                         break;
2913
2914                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2915                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2916                 case SPECIFIER_LONG | SPECIFIER_LONG_LONG | SPECIFIER_INT:
2917                 case SPECIFIER_SIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2918                         | SPECIFIER_INT:
2919                         atomic_type = ATOMIC_TYPE_LONGLONG;
2920                         goto warn_about_long_long;
2921
2922                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG:
2923                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG
2924                         | SPECIFIER_INT:
2925                         atomic_type = ATOMIC_TYPE_ULONGLONG;
2926 warn_about_long_long:
2927                         warningf(WARN_LONG_LONG, &specifiers->pos, "ISO C90 does not support 'long long'");
2928                         break;
2929
2930                 case SPECIFIER_UNSIGNED | SPECIFIER_INT8:
2931                         atomic_type = unsigned_int8_type_kind;
2932                         break;
2933
2934                 case SPECIFIER_UNSIGNED | SPECIFIER_INT16:
2935                         atomic_type = unsigned_int16_type_kind;
2936                         break;
2937
2938                 case SPECIFIER_UNSIGNED | SPECIFIER_INT32:
2939                         atomic_type = unsigned_int32_type_kind;
2940                         break;
2941
2942                 case SPECIFIER_UNSIGNED | SPECIFIER_INT64:
2943                         atomic_type = unsigned_int64_type_kind;
2944                         break;
2945
2946                 case SPECIFIER_UNSIGNED | SPECIFIER_INT128:
2947                         atomic_type = unsigned_int128_type_kind;
2948                         break;
2949
2950                 case SPECIFIER_INT8:
2951                 case SPECIFIER_SIGNED | SPECIFIER_INT8:
2952                         atomic_type = int8_type_kind;
2953                         break;
2954
2955                 case SPECIFIER_INT16:
2956                 case SPECIFIER_SIGNED | SPECIFIER_INT16:
2957                         atomic_type = int16_type_kind;
2958                         break;
2959
2960                 case SPECIFIER_INT32:
2961                 case SPECIFIER_SIGNED | SPECIFIER_INT32:
2962                         atomic_type = int32_type_kind;
2963                         break;
2964
2965                 case SPECIFIER_INT64:
2966                 case SPECIFIER_SIGNED | SPECIFIER_INT64:
2967                         atomic_type = int64_type_kind;
2968                         break;
2969
2970                 case SPECIFIER_INT128:
2971                 case SPECIFIER_SIGNED | SPECIFIER_INT128:
2972                         atomic_type = int128_type_kind;
2973                         break;
2974
2975                 case SPECIFIER_FLOAT:
2976                         atomic_type = ATOMIC_TYPE_FLOAT;
2977                         break;
2978                 case SPECIFIER_DOUBLE:
2979                         atomic_type = ATOMIC_TYPE_DOUBLE;
2980                         break;
2981                 case SPECIFIER_LONG | SPECIFIER_DOUBLE:
2982                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2983                         break;
2984                 case SPECIFIER_BOOL:
2985                         atomic_type = ATOMIC_TYPE_BOOL;
2986                         break;
2987                 case SPECIFIER_FLOAT | SPECIFIER_COMPLEX:
2988                 case SPECIFIER_FLOAT | SPECIFIER_IMAGINARY:
2989                         atomic_type = ATOMIC_TYPE_FLOAT;
2990                         break;
2991                 case SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2992                 case SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2993                         atomic_type = ATOMIC_TYPE_DOUBLE;
2994                         break;
2995                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_COMPLEX:
2996                 case SPECIFIER_LONG | SPECIFIER_DOUBLE | SPECIFIER_IMAGINARY:
2997                         atomic_type = ATOMIC_TYPE_LONG_DOUBLE;
2998                         break;
2999                 default: {
3000                         /* invalid specifier combination, give an error message */
3001                         position_t const* const pos = &specifiers->pos;
3002                         if (type_specifiers == 0) {
3003                                 if (!saw_error) {
3004                                         /* ISO/IEC 14882:1998(E) §C.1.5:4 */
3005                                         if (!(c_mode & _CXX) && !strict_mode) {
3006                                                 warningf(WARN_IMPLICIT_INT, pos, "no type specifiers in declaration, using 'int'");
3007                                                 atomic_type = ATOMIC_TYPE_INT;
3008                                                 break;
3009                                         } else {
3010                                                 errorf(pos, "no type specifiers given in declaration");
3011                                         }
3012                                 }
3013                         } else if ((type_specifiers & SPECIFIER_SIGNED) &&
3014                                   (type_specifiers & SPECIFIER_UNSIGNED)) {
3015                                 errorf(pos, "signed and unsigned specifiers given");
3016                         } else if (type_specifiers & (SPECIFIER_SIGNED | SPECIFIER_UNSIGNED)) {
3017                                 errorf(pos, "only integer types can be signed or unsigned");
3018                         } else {
3019                                 errorf(pos, "multiple datatypes in declaration");
3020                         }
3021                         specifiers->type = type_error_type;
3022                         return;
3023                 }
3024                 }
3025
3026                 if (type_specifiers & SPECIFIER_COMPLEX) {
3027                         type = allocate_type_zero(TYPE_COMPLEX);
3028                 } else if (type_specifiers & SPECIFIER_IMAGINARY) {
3029                         type = allocate_type_zero(TYPE_IMAGINARY);
3030                 } else {
3031                         type = allocate_type_zero(TYPE_ATOMIC);
3032                 }
3033                 type->atomic.akind = atomic_type;
3034                 newtype = true;
3035         } else if (type_specifiers != 0) {
3036                 errorf(&specifiers->pos, "multiple datatypes in declaration");
3037         }
3038
3039         /* FIXME: check type qualifiers here */
3040         type->base.qualifiers = qualifiers;
3041
3042         if (newtype) {
3043                 type = identify_new_type(type);
3044         } else {
3045                 type = typehash_insert(type);
3046         }
3047
3048         if (specifiers->attributes != NULL)
3049                 type = handle_type_attributes(specifiers->attributes, type);
3050         specifiers->type = type;
3051 }
3052
3053 static type_qualifiers_t parse_type_qualifiers(void)
3054 {
3055         type_qualifiers_t qualifiers = TYPE_QUALIFIER_NONE;
3056
3057         while (true) {
3058                 switch (token.kind) {
3059                 /* type qualifiers */
3060                 MATCH_TYPE_QUALIFIER(T_const,    TYPE_QUALIFIER_CONST);
3061                 MATCH_TYPE_QUALIFIER(T_restrict, TYPE_QUALIFIER_RESTRICT);
3062                 MATCH_TYPE_QUALIFIER(T_volatile, TYPE_QUALIFIER_VOLATILE);
3063                 /* microsoft extended type modifiers */
3064                 MATCH_TYPE_QUALIFIER(T__w64,     TYPE_QUALIFIER_W64);
3065                 MATCH_TYPE_QUALIFIER(T___ptr32,  TYPE_QUALIFIER_PTR32);
3066                 MATCH_TYPE_QUALIFIER(T___ptr64,  TYPE_QUALIFIER_PTR64);
3067                 MATCH_TYPE_QUALIFIER(T___uptr,   TYPE_QUALIFIER_UPTR);
3068                 MATCH_TYPE_QUALIFIER(T___sptr,   TYPE_QUALIFIER_SPTR);
3069
3070                 default:
3071                         return qualifiers;
3072                 }
3073         }
3074 }
3075
3076 /**
3077  * Parses an K&R identifier list
3078  */
3079 static void parse_identifier_list(scope_t *scope)
3080 {
3081         assert(token.kind == T_IDENTIFIER);
3082         do {
3083                 entity_t *const entity = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, token.base.symbol, HERE);
3084                 /* a K&R parameter has no type, yet */
3085                 eat(T_IDENTIFIER);
3086
3087                 if (scope != NULL)
3088                         append_entity(scope, entity);
3089         } while (accept(',') && token.kind == T_IDENTIFIER);
3090 }
3091
3092 static entity_t *parse_parameter(void)
3093 {
3094         declaration_specifiers_t specifiers;
3095         parse_declaration_specifiers(&specifiers);
3096
3097         entity_t *entity = parse_declarator(&specifiers,
3098                         DECL_MAY_BE_ABSTRACT | DECL_IS_PARAMETER);
3099         anonymous_entity = NULL;
3100         return entity;
3101 }
3102
3103 static void semantic_parameter_incomplete(const entity_t *entity)
3104 {
3105         assert(entity->kind == ENTITY_PARAMETER);
3106
3107         /* §6.7.5.3:4  After adjustment, the parameters in a parameter type
3108          *             list in a function declarator that is part of a
3109          *             definition of that function shall not have
3110          *             incomplete type. */
3111         type_t *type = skip_typeref(entity->declaration.type);
3112         if (is_type_incomplete(type)) {
3113                 errorf(&entity->base.pos, "'%N' has incomplete type", entity);
3114         }
3115 }
3116
3117 static bool has_parameters(void)
3118 {
3119         /* func(void) is not a parameter */
3120         if (look_ahead(1)->kind != ')')
3121                 return true;
3122         if (token.kind == T_IDENTIFIER) {
3123                 entity_t const *const entity = get_entity(token.base.symbol, NAMESPACE_NORMAL);
3124                 if (entity == NULL)
3125                         return true;
3126                 if (entity->kind != ENTITY_TYPEDEF)
3127                         return true;
3128                 type_t const *const type = skip_typeref(entity->typedefe.type);
3129                 if (!is_type_void(type))
3130                         return true;
3131                 if (c_mode & _CXX) {
3132                         /* ISO/IEC 14882:1998(E) §8.3.5:2  It must be literally (void).  A typedef
3133                          * is not allowed. */
3134                         errorf(HERE, "empty parameter list defined with a typedef of 'void' not allowed in C++");
3135                 } else if (type->base.qualifiers != TYPE_QUALIFIER_NONE) {
3136                         /* §6.7.5.3:10  Qualification is not allowed here. */
3137                         errorf(HERE, "'void' as parameter must not have type qualifiers");
3138                 }
3139         } else if (token.kind != T_void) {
3140                 return true;
3141         }
3142         next_token();
3143         return false;
3144 }
3145
3146 /**
3147  * Parses function type parameters (and optionally creates variable_t entities
3148  * for them in a scope)
3149  */
3150 static void parse_parameters(function_type_t *type, scope_t *scope)
3151 {
3152         add_anchor_token(')');
3153         eat('(');
3154
3155         if (token.kind == T_IDENTIFIER            &&
3156             !is_typedef_symbol(token.base.symbol) &&
3157             (look_ahead(1)->kind == ',' || look_ahead(1)->kind == ')')) {
3158                 type->kr_style_parameters = true;
3159                 parse_identifier_list(scope);
3160         } else if (token.kind == ')') {
3161                 /* ISO/IEC 14882:1998(E) §C.1.6:1 */
3162                 if (!(c_mode & _CXX))
3163                         type->unspecified_parameters = true;
3164         } else if (has_parameters()) {
3165                 function_parameter_t **anchor = &type->parameters;
3166                 add_anchor_token(',');
3167                 do {
3168                         switch (token.kind) {
3169                         case T_DOTDOTDOT:
3170                                 eat(T_DOTDOTDOT);
3171                                 type->variadic = true;
3172                                 goto parameters_finished;
3173
3174                         case T_IDENTIFIER:
3175                         DECLARATION_START
3176                         {
3177                                 entity_t *entity = parse_parameter();
3178                                 if (entity->kind == ENTITY_TYPEDEF) {
3179                                         errorf(&entity->base.pos,
3180                                                         "typedef not allowed as function parameter");
3181                                         break;
3182                                 }
3183                                 assert(is_declaration(entity));
3184
3185                                 semantic_parameter_incomplete(entity);
3186
3187                                 function_parameter_t *const parameter =
3188                                         allocate_parameter(entity->declaration.type);
3189
3190                                 if (scope != NULL) {
3191                                         append_entity(scope, entity);
3192                                 }
3193
3194                                 *anchor = parameter;
3195                                 anchor  = &parameter->next;
3196                                 break;
3197                         }
3198
3199                         default:
3200                                 goto parameters_finished;
3201                         }
3202                 } while (accept(','));
3203 parameters_finished:
3204                 rem_anchor_token(',');
3205         }
3206
3207         rem_anchor_token(')');
3208         expect(')');
3209 }
3210
3211 typedef enum construct_type_kind_t {
3212         CONSTRUCT_POINTER = 1,
3213         CONSTRUCT_REFERENCE,
3214         CONSTRUCT_FUNCTION,
3215         CONSTRUCT_ARRAY
3216 } construct_type_kind_t;
3217
3218 typedef union construct_type_t construct_type_t;
3219
3220 typedef struct construct_type_base_t {
3221         construct_type_kind_t kind;
3222         position_t            pos;
3223         construct_type_t     *next;
3224 } construct_type_base_t;
3225
3226 typedef struct parsed_pointer_t {
3227         construct_type_base_t  base;
3228         type_qualifiers_t      type_qualifiers;
3229         variable_t            *base_variable;  /**< MS __based extension. */
3230 } parsed_pointer_t;
3231
3232 typedef struct parsed_reference_t {
3233         construct_type_base_t base;
3234 } parsed_reference_t;
3235
3236 typedef struct construct_function_type_t {
3237         construct_type_base_t  base;
3238         type_t                *function_type;
3239 } construct_function_type_t;
3240
3241 typedef struct parsed_array_t {
3242         construct_type_base_t  base;
3243         type_qualifiers_t      type_qualifiers;
3244         bool                   is_static;
3245         bool                   is_variable;
3246         expression_t          *size;
3247 } parsed_array_t;
3248
3249 union construct_type_t {
3250         construct_type_kind_t     kind;
3251         construct_type_base_t     base;
3252         parsed_pointer_t          pointer;
3253         parsed_reference_t        reference;
3254         construct_function_type_t function;
3255         parsed_array_t            array;
3256 };
3257
3258 static construct_type_t *allocate_declarator_zero(construct_type_kind_t const kind, size_t const size)
3259 {
3260         construct_type_t *const cons = obstack_alloc(&temp_obst, size);
3261         memset(cons, 0, size);
3262         cons->kind     = kind;
3263         cons->base.pos = *HERE;
3264         return cons;
3265 }
3266
3267 /* §6.7.5.1 */
3268 static construct_type_t *parse_pointer_declarator(void)
3269 {
3270         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_POINTER, sizeof(parsed_pointer_t));
3271         eat('*');
3272         cons->pointer.type_qualifiers = parse_type_qualifiers();
3273         //cons->pointer.base_variable   = base_variable;
3274
3275         return cons;
3276 }
3277
3278 /* ISO/IEC 14882:1998(E) §8.3.2 */
3279 static construct_type_t *parse_reference_declarator(void)
3280 {
3281         if (!(c_mode & _CXX))
3282                 errorf(HERE, "references are only available for C++");
3283
3284         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_REFERENCE, sizeof(parsed_reference_t));
3285         eat('&');
3286
3287         return cons;
3288 }
3289
3290 /* §6.7.5.2 */
3291 static construct_type_t *parse_array_declarator(void)
3292 {
3293         construct_type_t *const cons  = allocate_declarator_zero(CONSTRUCT_ARRAY, sizeof(parsed_array_t));
3294         parsed_array_t   *const array = &cons->array;
3295
3296         eat('[');
3297         add_anchor_token(']');
3298
3299         bool is_static = accept(T_static);
3300
3301         type_qualifiers_t type_qualifiers = parse_type_qualifiers();
3302
3303         if (!is_static)
3304                 is_static = accept(T_static);
3305
3306         array->type_qualifiers = type_qualifiers;
3307         array->is_static       = is_static;
3308
3309         expression_t *size = NULL;
3310         if (token.kind == '*' && look_ahead(1)->kind == ']') {
3311                 array->is_variable = true;
3312                 eat('*');
3313         } else if (token.kind != ']') {
3314                 size = parse_assignment_expression();
3315
3316                 /* §6.7.5.2:1  Array size must have integer type */
3317                 type_t *const orig_type = size->base.type;
3318                 type_t *const type      = skip_typeref(orig_type);
3319                 if (!is_type_integer(type) && is_type_valid(type)) {
3320                         errorf(&size->base.pos,
3321                                "array size '%E' must have integer type but has type '%T'",
3322                                size, orig_type);
3323                 }
3324
3325                 array->size = size;
3326                 mark_vars_read(size, NULL);
3327         }
3328
3329         if (is_static && size == NULL)
3330                 errorf(&array->base.pos, "static array parameters require a size");
3331
3332         rem_anchor_token(']');
3333         expect(']');
3334         return cons;
3335 }
3336
3337 /* §6.7.5.3 */
3338 static construct_type_t *parse_function_declarator(scope_t *scope)
3339 {
3340         construct_type_t *const cons = allocate_declarator_zero(CONSTRUCT_FUNCTION, sizeof(construct_function_type_t));
3341
3342         type_t          *type  = allocate_type_zero(TYPE_FUNCTION);
3343         function_type_t *ftype = &type->function;
3344
3345         ftype->linkage            = current_linkage;
3346         ftype->calling_convention = CC_DEFAULT;
3347
3348         parse_parameters(ftype, scope);
3349
3350         cons->function.function_type = type;
3351
3352         return cons;
3353 }
3354
3355 typedef struct parse_declarator_env_t {
3356         bool              may_be_abstract : 1;
3357         bool              must_be_abstract : 1;
3358         decl_modifiers_t  modifiers;
3359         symbol_t         *symbol;
3360         position_t        pos;
3361         scope_t           parameters;
3362         attribute_t      *attributes;
3363 } parse_declarator_env_t;
3364
3365 /* §6.7.5 */
3366 static construct_type_t *parse_inner_declarator(parse_declarator_env_t *env)
3367 {
3368         /* construct a single linked list of construct_type_t's which describe
3369          * how to construct the final declarator type */
3370         construct_type_t  *first      = NULL;
3371         construct_type_t **anchor     = &first;
3372
3373         env->attributes = parse_attributes(env->attributes);
3374
3375         for (;;) {
3376                 construct_type_t *type;
3377                 //variable_t       *based = NULL; /* MS __based extension */
3378                 switch (token.kind) {
3379                         case '&':
3380                                 type = parse_reference_declarator();
3381                                 break;
3382
3383                         case T__based: {
3384                                 panic("based not supported anymore");
3385                                 /* FALLTHROUGH */
3386                         }
3387
3388                         case '*':
3389                                 type = parse_pointer_declarator();
3390                                 break;
3391
3392                         default:
3393                                 goto ptr_operator_end;
3394                 }
3395
3396                 *anchor = type;
3397                 anchor  = &type->base.next;
3398
3399                 /* TODO: find out if this is correct */
3400                 env->attributes = parse_attributes(env->attributes);
3401         }
3402
3403 ptr_operator_end: ;
3404         construct_type_t *inner_types = NULL;
3405
3406         switch (token.kind) {
3407         case T_IDENTIFIER:
3408                 if (env->must_be_abstract) {
3409                         errorf(HERE, "no identifier expected in typename");
3410                 } else {
3411                         env->symbol = token.base.symbol;
3412                         env->pos    = *HERE;
3413                 }
3414                 eat(T_IDENTIFIER);
3415                 break;
3416
3417         case '(': {
3418                 /* Parenthesized declarator or function declarator? */
3419                 token_t const *const la1 = look_ahead(1);
3420                 switch (la1->kind) {
3421                         case T_IDENTIFIER:
3422                                 if (is_typedef_symbol(la1->base.symbol)) {
3423                         case ')':
3424                                         /* §6.7.6:2 footnote 126:  Empty parentheses in a type name are
3425                                          * interpreted as ``function with no parameter specification'', rather
3426                                          * than redundant parentheses around the omitted identifier. */
3427                         default:
3428                                         /* Function declarator. */
3429                                         if (!env->may_be_abstract) {
3430                                                 errorf(HERE, "function declarator must have a name");
3431                                         }
3432                                 } else {
3433                         case '&':
3434                         case '(':
3435                         case '*':
3436                         case '[':
3437                         case T___attribute__: /* FIXME __attribute__ might also introduce a parameter of a function declarator. */
3438                                         /* Paranthesized declarator. */
3439                                         eat('(');
3440                                         add_anchor_token(')');
3441                                         inner_types = parse_inner_declarator(env);
3442                                         if (inner_types != NULL) {
3443                                                 /* All later declarators only modify the return type */
3444                                                 env->must_be_abstract = true;
3445                                         }
3446                                         rem_anchor_token(')');
3447                                         expect(')');
3448                                 }
3449                                 break;
3450                 }
3451                 break;
3452         }
3453
3454         default:
3455                 if (env->may_be_abstract)
3456                         break;
3457                 parse_error_expected("while parsing declarator", T_IDENTIFIER, '(', NULL);
3458                 eat_until_anchor();
3459                 return NULL;
3460         }
3461
3462         construct_type_t **const p = anchor;
3463
3464         for (;;) {
3465                 construct_type_t *type;
3466                 switch (token.kind) {
3467                 case '(': {
3468                         scope_t *scope = NULL;
3469                         if (!env->must_be_abstract) {
3470                                 scope = &env->parameters;
3471                         }
3472
3473                         type = parse_function_declarator(scope);
3474                         break;
3475                 }
3476                 case '[':
3477                         type = parse_array_declarator();
3478                         break;
3479                 default:
3480                         goto declarator_finished;
3481                 }
3482
3483                 /* insert in the middle of the list (at p) */
3484                 type->base.next = *p;
3485                 *p              = type;
3486                 if (anchor == p)
3487                         anchor = &type->base.next;
3488         }
3489
3490 declarator_finished:
3491         /* append inner_types at the end of the list, we don't to set anchor anymore
3492          * as it's not needed anymore */
3493         *anchor = inner_types;
3494
3495         return first;
3496 }
3497
3498 static type_t *construct_declarator_type(construct_type_t *construct_list,
3499                                          type_t *type)
3500 {
3501         construct_type_t *iter = construct_list;
3502         for (; iter != NULL; iter = iter->base.next) {
3503                 position_t const* const pos = &iter->base.pos;
3504                 switch (iter->kind) {
3505                 case CONSTRUCT_FUNCTION: {
3506                         construct_function_type_t *function      = &iter->function;
3507                         type_t                    *function_type = function->function_type;
3508
3509                         function_type->function.return_type = type;
3510
3511                         type_t *skipped_return_type = skip_typeref(type);
3512                         /* §6.7.5.3:1 */
3513                         if (is_type_function(skipped_return_type)) {
3514                                 errorf(pos, "function returning function is not allowed");
3515                         } else if (is_type_array(skipped_return_type)) {
3516                                 errorf(pos, "function returning array is not allowed");
3517                         } else {
3518                                 if (skipped_return_type->base.qualifiers != 0) {
3519                                         warningf(WARN_IGNORED_QUALIFIERS, pos, "type qualifiers in return type of function type are meaningless");
3520                                 }
3521                         }
3522
3523                         /* The function type was constructed earlier.  Freeing it here will
3524                          * destroy other types. */
3525                         type = typehash_insert(function_type);
3526                         continue;
3527                 }
3528
3529                 case CONSTRUCT_POINTER: {
3530                         if (is_type_reference(skip_typeref(type)))
3531                                 errorf(pos, "cannot declare a pointer to reference");
3532
3533                         parsed_pointer_t *pointer = &iter->pointer;
3534                         type = make_based_pointer_type(type, pointer->type_qualifiers, pointer->base_variable);
3535                         continue;
3536                 }
3537
3538                 case CONSTRUCT_REFERENCE:
3539                         if (is_type_reference(skip_typeref(type)))
3540                                 errorf(pos, "cannot declare a reference to reference");
3541
3542                         type = make_reference_type(type);
3543                         continue;
3544
3545                 case CONSTRUCT_ARRAY: {
3546                         if (is_type_reference(skip_typeref(type)))
3547                                 errorf(pos, "cannot declare an array of references");
3548
3549                         parsed_array_t *array      = &iter->array;
3550                         type_t         *array_type = allocate_type_zero(TYPE_ARRAY);
3551
3552                         expression_t *size_expression = array->size;
3553                         if (size_expression != NULL) {
3554                                 size_expression
3555                                         = create_implicit_cast(size_expression, type_size_t);
3556                         }
3557
3558                         array_type->base.qualifiers       = array->type_qualifiers;
3559                         array_type->array.element_type    = type;
3560                         array_type->array.is_static       = array->is_static;
3561                         array_type->array.is_variable     = array->is_variable;
3562                         array_type->array.size_expression = size_expression;
3563
3564                         if (size_expression != NULL) {
3565                                 switch (is_constant_expression(size_expression)) {
3566                                 case EXPR_CLASS_CONSTANT: {
3567                                         long const size = fold_constant_to_int(size_expression);
3568                                         array_type->array.size          = size;
3569                                         array_type->array.size_constant = true;
3570                                         /* §6.7.5.2:1  If the expression is a constant expression,
3571                                          * it shall have a value greater than zero. */
3572                                         if (size < 0) {
3573                                                 errorf(&size_expression->base.pos,
3574                                                            "size of array must be greater than zero");
3575                                         } else if (size == 0 && !GNU_MODE) {
3576                                                 errorf(&size_expression->base.pos,
3577                                                            "size of array must be greater than zero (zero length arrays are a GCC extension)");
3578                                         }
3579                                         break;
3580                                 }
3581
3582                                 case EXPR_CLASS_VARIABLE:
3583                                         array_type->array.is_vla = true;
3584                                         break;
3585
3586                                 case EXPR_CLASS_ERROR:
3587                                         break;
3588                                 }
3589                         }
3590
3591                         type_t *skipped_type = skip_typeref(type);
3592                         /* §6.7.5.2:1 */
3593                         if (is_type_incomplete(skipped_type)) {
3594                                 errorf(pos, "array of incomplete type '%T' is not allowed", type);
3595                         } else if (is_type_function(skipped_type)) {
3596                                 errorf(pos, "array of functions is not allowed");
3597                         }
3598                         type = identify_new_type(array_type);
3599                         continue;
3600                 }
3601                 }
3602                 internal_errorf(pos, "invalid type construction found");
3603         }
3604
3605         return type;
3606 }
3607
3608 static type_t *automatic_type_conversion(type_t *orig_type);
3609
3610 static type_t *semantic_parameter(const position_t *pos, type_t *type,
3611                                   const declaration_specifiers_t *specifiers,
3612                                   entity_t const *const param)
3613 {
3614         /* §6.7.5.3:7  A declaration of a parameter as ``array of type''
3615          *             shall be adjusted to ``qualified pointer to type'',
3616          *             [...]
3617          * §6.7.5.3:8  A declaration of a parameter as ``function returning
3618          *             type'' shall be adjusted to ``pointer to function
3619          *             returning type'', as in 6.3.2.1. */
3620         type = automatic_type_conversion(type);
3621
3622         if (specifiers->is_inline && is_type_valid(type)) {
3623                 errorf(pos, "'%N' declared 'inline'", param);
3624         }
3625
3626         /* §6.9.1:6  The declarations in the declaration list shall contain
3627          *           no storage-class specifier other than register and no
3628          *           initializations. */
3629         if (specifiers->thread_local || (
3630                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3631                         specifiers->storage_class != STORAGE_CLASS_REGISTER)
3632            ) {
3633                 errorf(pos, "invalid storage class for '%N'", param);
3634         }
3635
3636         /* delay test for incomplete type, because we might have (void)
3637          * which is legal but incomplete... */
3638
3639         return type;
3640 }
3641
3642 static entity_t *parse_declarator(const declaration_specifiers_t *specifiers,
3643                                   declarator_flags_t flags)
3644 {
3645         parse_declarator_env_t env;
3646         memset(&env, 0, sizeof(env));
3647         env.may_be_abstract = (flags & DECL_MAY_BE_ABSTRACT) != 0;
3648
3649         construct_type_t *construct_type = parse_inner_declarator(&env);
3650         type_t           *orig_type      =
3651                 construct_declarator_type(construct_type, specifiers->type);
3652         type_t           *type           = skip_typeref(orig_type);
3653
3654         if (construct_type != NULL) {
3655                 obstack_free(&temp_obst, construct_type);
3656         }
3657
3658         attribute_t *attributes = parse_attributes(env.attributes);
3659         /* append (shared) specifier attribute behind attributes of this
3660          * declarator */
3661         attribute_t **anchor = &attributes;
3662         while (*anchor != NULL)
3663                 anchor = &(*anchor)->next;
3664         *anchor = specifiers->attributes;
3665
3666         entity_t *entity;
3667         if (specifiers->storage_class == STORAGE_CLASS_TYPEDEF) {
3668                 entity = allocate_entity_zero(ENTITY_TYPEDEF, NAMESPACE_NORMAL, env.symbol, &env.pos);
3669                 entity->typedefe.type = orig_type;
3670
3671                 if (anonymous_entity != NULL) {
3672                         if (is_type_compound(type)) {
3673                                 assert(anonymous_entity->compound.alias == NULL);
3674                                 assert(anonymous_entity->kind == ENTITY_STRUCT ||
3675                                        anonymous_entity->kind == ENTITY_UNION);
3676                                 anonymous_entity->compound.alias = entity;
3677                                 anonymous_entity = NULL;
3678                         } else if (is_type_enum(type)) {
3679                                 assert(anonymous_entity->enume.alias == NULL);
3680                                 assert(anonymous_entity->kind == ENTITY_ENUM);
3681                                 anonymous_entity->enume.alias = entity;
3682                                 anonymous_entity = NULL;
3683                         }
3684                 }
3685         } else {
3686                 /* create a declaration type entity */
3687                 position_t const *const pos = env.symbol ? &env.pos : &specifiers->pos;
3688                 if (flags & DECL_CREATE_COMPOUND_MEMBER) {
3689                         entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, env.symbol, pos);
3690
3691                         if (env.symbol != NULL) {
3692                                 if (specifiers->is_inline && is_type_valid(type)) {
3693                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3694                                 }
3695
3696                                 if (specifiers->thread_local ||
3697                                                 specifiers->storage_class != STORAGE_CLASS_NONE) {
3698                                         errorf(&env.pos, "'%N' must have no storage class", entity);
3699                                 }
3700                         }
3701                 } else if (flags & DECL_IS_PARAMETER) {
3702                         entity    = allocate_entity_zero(ENTITY_PARAMETER, NAMESPACE_NORMAL, env.symbol, pos);
3703                         orig_type = semantic_parameter(&env.pos, orig_type, specifiers, entity);
3704                 } else if (is_type_function(type)) {
3705                         entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, env.symbol, pos);
3706                         entity->function.is_inline      = specifiers->is_inline;
3707                         entity->function.elf_visibility = default_visibility;
3708                         entity->function.parameters     = env.parameters;
3709
3710                         if (env.symbol != NULL) {
3711                                 /* this needs fixes for C++ */
3712                                 bool in_function_scope = current_function != NULL;
3713
3714                                 if (specifiers->thread_local || (
3715                                                         specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3716                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3717                                                         (in_function_scope || specifiers->storage_class != STORAGE_CLASS_STATIC)
3718                                                 )) {
3719                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3720                                 }
3721                         }
3722                 } else {
3723                         entity = allocate_entity_zero(ENTITY_VARIABLE, NAMESPACE_NORMAL, env.symbol, pos);
3724                         entity->variable.elf_visibility = default_visibility;
3725                         entity->variable.thread_local   = specifiers->thread_local;
3726
3727                         if (env.symbol != NULL) {
3728                                 if (specifiers->is_inline && is_type_valid(type)) {
3729                                         errorf(&env.pos, "'%N' declared 'inline'", entity);
3730                                 }
3731
3732                                 bool invalid_storage_class = false;
3733                                 if (current_scope == file_scope) {
3734                                         if (specifiers->storage_class != STORAGE_CLASS_EXTERN &&
3735                                                         specifiers->storage_class != STORAGE_CLASS_NONE   &&
3736                                                         specifiers->storage_class != STORAGE_CLASS_STATIC) {
3737                                                 invalid_storage_class = true;
3738                                         }
3739                                 } else {
3740                                         if (specifiers->thread_local &&
3741                                                         specifiers->storage_class == STORAGE_CLASS_NONE) {
3742                                                 invalid_storage_class = true;
3743                                         }
3744                                 }
3745                                 if (invalid_storage_class) {
3746                                         errorf(&env.pos, "invalid storage class for '%N'", entity);
3747                                 }
3748                         }
3749                 }
3750
3751                 entity->declaration.type       = orig_type;
3752                 entity->declaration.alignment  = get_type_alignment(orig_type);
3753                 entity->declaration.modifiers  = env.modifiers;
3754                 entity->declaration.attributes = attributes;
3755
3756                 storage_class_t storage_class = specifiers->storage_class;
3757                 entity->declaration.declared_storage_class = storage_class;
3758
3759                 if (storage_class == STORAGE_CLASS_NONE && current_function != NULL)
3760                         storage_class = STORAGE_CLASS_AUTO;
3761                 entity->declaration.storage_class = storage_class;
3762         }
3763
3764         if (attributes != NULL) {
3765                 handle_entity_attributes(attributes, entity);
3766         }
3767
3768         if (entity->kind == ENTITY_FUNCTION && !freestanding) {
3769                 adapt_special_functions(&entity->function);
3770         }
3771
3772         return entity;
3773 }
3774
3775 static type_t *parse_abstract_declarator(type_t *base_type)
3776 {
3777         parse_declarator_env_t env;
3778         memset(&env, 0, sizeof(env));
3779         env.may_be_abstract = true;
3780         env.must_be_abstract = true;
3781
3782         construct_type_t *construct_type = parse_inner_declarator(&env);
3783
3784         type_t *result = construct_declarator_type(construct_type, base_type);
3785         if (construct_type != NULL) {
3786                 obstack_free(&temp_obst, construct_type);
3787         }
3788         result = handle_type_attributes(env.attributes, result);
3789
3790         return result;
3791 }
3792
3793 /**
3794  * Check if the declaration of main is suspicious.  main should be a
3795  * function with external linkage, returning int, taking either zero
3796  * arguments, two, or three arguments of appropriate types, ie.
3797  *
3798  * int main([ int argc, char **argv [, char **env ] ]).
3799  *
3800  * @param decl    the declaration to check
3801  * @param type    the function type of the declaration
3802  */
3803 static void check_main(const entity_t *entity)
3804 {
3805         const position_t *pos = &entity->base.pos;
3806         if (entity->kind != ENTITY_FUNCTION) {
3807                 warningf(WARN_MAIN, pos, "'main' is not a function");
3808                 return;
3809         }
3810
3811         if (entity->declaration.storage_class == STORAGE_CLASS_STATIC) {
3812                 warningf(WARN_MAIN, pos, "'main' is normally a non-static function");
3813         }
3814
3815         type_t *type = skip_typeref(entity->declaration.type);
3816         assert(is_type_function(type));
3817
3818         function_type_t const *const func_type = &type->function;
3819         type_t                *const ret_type  = func_type->return_type;
3820         if (!types_compatible(skip_typeref(ret_type), type_int)) {
3821                 warningf(WARN_MAIN, pos, "return type of 'main' should be 'int', but is '%T'", ret_type);
3822         }
3823         const function_parameter_t *parm = func_type->parameters;
3824         if (parm != NULL) {
3825                 type_t *const first_type        = skip_typeref(parm->type);
3826                 type_t *const first_type_unqual = get_unqualified_type(first_type);
3827                 if (!types_compatible(first_type_unqual, type_int)) {
3828                         warningf(WARN_MAIN, pos, "first argument of 'main' should be 'int', but is '%T'", parm->type);
3829                 }
3830                 parm = parm->next;
3831                 if (parm != NULL) {
3832                         type_t *const second_type = skip_typeref(parm->type);
3833                         type_t *const second_type_unqual
3834                                 = get_unqualified_type(second_type);
3835                         if (!types_compatible(second_type_unqual, type_char_ptr_ptr)) {
3836                                 warningf(WARN_MAIN, pos, "second argument of 'main' should be 'char**', but is '%T'", parm->type);
3837                         }
3838                         parm = parm->next;
3839                         if (parm != NULL) {
3840                                 type_t *const third_type = skip_typeref(parm->type);
3841                                 type_t *const third_type_unqual
3842                                         = get_unqualified_type(third_type);
3843                                 if (!types_compatible(third_type_unqual, type_char_ptr_ptr)) {
3844                                         warningf(WARN_MAIN, pos, "third argument of 'main' should be 'char**', but is '%T'", parm->type);
3845                                 }
3846                                 parm = parm->next;
3847                                 if (parm != NULL)
3848                                         goto warn_arg_count;
3849                         }
3850                 } else {
3851 warn_arg_count:
3852                         warningf(WARN_MAIN, pos, "'main' takes only zero, two or three arguments");
3853                 }
3854         }
3855 }
3856
3857 static void error_redefined_as_different_kind(const position_t *pos,
3858                 const entity_t *old, entity_kind_t new_kind)
3859 {
3860         char       const *const what = get_entity_kind_name(new_kind);
3861         position_t const *const ppos = &old->base.pos;
3862         errorf(pos, "redeclaration of '%N' as %s (declared %P)", old, what, ppos);
3863 }
3864
3865 static bool is_entity_valid(entity_t *const ent)
3866 {
3867         if (is_declaration(ent)) {
3868                 return is_type_valid(skip_typeref(ent->declaration.type));
3869         } else if (ent->kind == ENTITY_TYPEDEF) {
3870                 return is_type_valid(skip_typeref(ent->typedefe.type));
3871         }
3872         return true;
3873 }
3874
3875 static bool contains_attribute(const attribute_t *list, const attribute_t *attr)
3876 {
3877         for (const attribute_t *tattr = list; tattr != NULL; tattr = tattr->next) {
3878                 if (attributes_equal(tattr, attr))
3879                         return true;
3880         }
3881         return false;
3882 }
3883
3884 /**
3885  * Tests whether new_list contains any attributes not included in old_list
3886  */
3887 static bool has_new_attributes(const attribute_t *old_list,
3888                                const attribute_t *new_list)
3889 {
3890         for (const attribute_t *attr = new_list; attr != NULL; attr = attr->next) {
3891                 if (!contains_attribute(old_list, attr))
3892                         return true;
3893         }
3894         return false;
3895 }
3896
3897 /**
3898  * Merge in attributes from an attribute list (probably from a previous
3899  * declaration with the same name). Warning: destroys the old structure
3900  * of the attribute list - don't reuse attributes after this call.
3901  */
3902 static void merge_in_attributes(declaration_t *decl, attribute_t *attributes)
3903 {
3904         attribute_t *next;
3905         for (attribute_t *attr = attributes; attr != NULL; attr = next) {
3906                 next = attr->next;
3907                 if (contains_attribute(decl->attributes, attr))
3908                         continue;
3909
3910                 /* move attribute to new declarations attributes list */
3911                 attr->next       = decl->attributes;
3912                 decl->attributes = attr;
3913         }
3914 }
3915
3916 static bool is_main(entity_t*);
3917
3918 /**
3919  * record entities for the NAMESPACE_NORMAL, and produce error messages/warnings
3920  * for various problems that occur for multiple definitions
3921  */
3922 entity_t *record_entity(entity_t *entity, const bool is_definition)
3923 {
3924         const symbol_t *const symbol  = entity->base.symbol;
3925         const namespace_tag_t namespc = (namespace_tag_t)entity->base.namespc;
3926         const position_t     *pos     = &entity->base.pos;
3927
3928         /* can happen in error cases */
3929         if (symbol == NULL)
3930                 return entity;
3931
3932         assert(!entity->base.parent_scope);
3933         assert(current_scope);
3934         entity->base.parent_scope = current_scope;
3935
3936         entity_t *const previous_entity = get_entity(symbol, namespc);
3937         /* pushing the same entity twice will break the stack structure */
3938         assert(previous_entity != entity);
3939
3940         if (entity->kind == ENTITY_FUNCTION) {
3941                 type_t *const orig_type = entity->declaration.type;
3942                 type_t *const type      = skip_typeref(orig_type);
3943
3944                 assert(is_type_function(type));
3945                 if (type->function.unspecified_parameters &&
3946                     previous_entity == NULL               &&
3947                     !entity->declaration.implicit) {
3948                         warningf(WARN_STRICT_PROTOTYPES, pos, "function declaration '%#N' is not a prototype", entity);
3949                 }
3950
3951                 if (is_main(entity)) {
3952                         check_main(entity);
3953                 }
3954         }
3955
3956         if (is_declaration(entity)                                    &&
3957             entity->declaration.storage_class == STORAGE_CLASS_EXTERN &&
3958             current_scope != file_scope                               &&
3959             !entity->declaration.implicit) {
3960                 warningf(WARN_NESTED_EXTERNS, pos, "nested extern declaration of '%#N'", entity);
3961         }
3962
3963         if (previous_entity != NULL) {
3964                 position_t const *const ppos = &previous_entity->base.pos;
3965
3966                 if (previous_entity->base.parent_scope == &current_function->parameters &&
3967                                 previous_entity->base.parent_scope->depth + 1 == current_scope->depth) {
3968                         assert(previous_entity->kind == ENTITY_PARAMETER);
3969                         errorf(pos, "declaration of '%N' redeclares the '%N' (declared %P)", entity, previous_entity, ppos);
3970                         goto finish;
3971                 }
3972
3973                 if (previous_entity->base.parent_scope == current_scope) {
3974                         if (previous_entity->kind != entity->kind) {
3975                                 if (is_entity_valid(previous_entity) && is_entity_valid(entity)) {
3976                                         error_redefined_as_different_kind(pos, previous_entity,
3977                                                         entity->kind);
3978                                 }
3979                                 goto finish;
3980                         }
3981                         if (previous_entity->kind == ENTITY_ENUM_VALUE) {
3982                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
3983                                 goto finish;
3984                         }
3985                         if (previous_entity->kind == ENTITY_TYPEDEF) {
3986                                 type_t *const type      = skip_typeref(entity->typedefe.type);
3987                                 type_t *const prev_type
3988                                         = skip_typeref(previous_entity->typedefe.type);
3989                                 if (c_mode & _CXX) {
3990                                         /* C++ allows double typedef if they are identical
3991                                          * (after skipping typedefs) */
3992                                         if (type == prev_type)
3993                                                 goto finish;
3994                                 } else {
3995                                         /* GCC extension: redef in system headers is allowed */
3996                                         if ((pos->is_system_header || ppos->is_system_header) &&
3997                                             types_compatible(type, prev_type))
3998                                                 goto finish;
3999                                 }
4000                                 errorf(pos, "redefinition of '%N' (declared %P)",
4001                                        entity, ppos);
4002                                 goto finish;
4003                         }
4004
4005                         /* at this point we should have only VARIABLES or FUNCTIONS */
4006                         assert(is_declaration(previous_entity) && is_declaration(entity));
4007
4008                         declaration_t *const prev_decl = &previous_entity->declaration;
4009                         declaration_t *const decl      = &entity->declaration;
4010
4011                         /* can happen for K&R style declarations */
4012                         if (prev_decl->type       == NULL             &&
4013                                         previous_entity->kind == ENTITY_PARAMETER &&
4014                                         entity->kind          == ENTITY_PARAMETER) {
4015                                 prev_decl->type                   = decl->type;
4016                                 prev_decl->storage_class          = decl->storage_class;
4017                                 prev_decl->declared_storage_class = decl->declared_storage_class;
4018                                 prev_decl->modifiers              = decl->modifiers;
4019                                 return previous_entity;
4020                         }
4021
4022                         type_t *const type      = skip_typeref(decl->type);
4023                         type_t *const prev_type = skip_typeref(prev_decl->type);
4024
4025                         if (!types_compatible(type, prev_type)) {
4026                                 errorf(pos, "declaration '%#N' is incompatible with '%#N' (declared %P)", entity, previous_entity, ppos);
4027                         } else {
4028                                 unsigned old_storage_class = prev_decl->storage_class;
4029
4030                                 if (is_definition                     &&
4031                                                 !prev_decl->used                  &&
4032                                                 !(prev_decl->modifiers & DM_USED) &&
4033                                                 prev_decl->storage_class == STORAGE_CLASS_STATIC) {
4034                                         warningf(WARN_REDUNDANT_DECLS, ppos, "unnecessary static forward declaration for '%#N'", previous_entity);
4035                                 }
4036
4037                                 storage_class_t new_storage_class = decl->storage_class;
4038
4039                                 /* pretend no storage class means extern for function
4040                                  * declarations (except if the previous declaration is neither
4041                                  * none nor extern) */
4042                                 if (entity->kind == ENTITY_FUNCTION) {
4043                                         /* the previous declaration could have unspecified parameters or
4044                                          * be a typedef, so use the new type */
4045                                         if (prev_type->function.unspecified_parameters || is_definition)
4046                                                 prev_decl->type = type;
4047
4048                                         switch (old_storage_class) {
4049                                                 case STORAGE_CLASS_NONE:
4050                                                         old_storage_class = STORAGE_CLASS_EXTERN;
4051                                                         /* FALLTHROUGH */
4052
4053                                                 case STORAGE_CLASS_EXTERN:
4054                                                         if (is_definition) {
4055                                                                 if (prev_type->function.unspecified_parameters && !is_main(entity)) {
4056                                                                         warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4057                                                                 }
4058                                                         } else if (new_storage_class == STORAGE_CLASS_NONE) {
4059                                                                 new_storage_class = STORAGE_CLASS_EXTERN;
4060                                                         }
4061                                                         break;
4062
4063                                                 default:
4064                                                         break;
4065                                         }
4066                                 } else if (is_type_incomplete(prev_type)) {
4067                                         prev_decl->type = type;
4068                                 }
4069
4070                                 if (old_storage_class == STORAGE_CLASS_EXTERN &&
4071                                                 new_storage_class == STORAGE_CLASS_EXTERN) {
4072
4073 warn_redundant_declaration: ;
4074                                         bool has_new_attrs
4075                                                 = has_new_attributes(prev_decl->attributes,
4076                                                                      decl->attributes);
4077                                         if (has_new_attrs) {
4078                                                 merge_in_attributes(decl, prev_decl->attributes);
4079                                         } else if (!is_definition        &&
4080                                                         is_type_valid(prev_type) &&
4081                                                         !pos->is_system_header) {
4082                                                 warningf(WARN_REDUNDANT_DECLS, pos, "redundant declaration for '%N' (declared %P)", entity, ppos);
4083                                         }
4084                                 } else if (current_function == NULL) {
4085                                         if (old_storage_class != STORAGE_CLASS_STATIC &&
4086                                                         new_storage_class == STORAGE_CLASS_STATIC) {
4087                                                 errorf(pos, "static declaration of '%N' follows non-static declaration (declared %P)", entity, ppos);
4088                                         } else if (old_storage_class == STORAGE_CLASS_EXTERN) {
4089                                                 prev_decl->storage_class          = STORAGE_CLASS_NONE;
4090                                                 prev_decl->declared_storage_class = STORAGE_CLASS_NONE;
4091                                         } else {
4092                                                 /* ISO/IEC 14882:1998(E) §C.1.2:1 */
4093                                                 if (c_mode & _CXX)
4094                                                         goto error_redeclaration;
4095                                                 goto warn_redundant_declaration;
4096                                         }
4097                                 } else if (is_type_valid(prev_type)) {
4098                                         if (old_storage_class == new_storage_class) {
4099 error_redeclaration:
4100                                                 errorf(pos, "redeclaration of '%N' (declared %P)", entity, ppos);
4101                                         } else {
4102                                                 errorf(pos, "redeclaration of '%N' with different linkage (declared %P)", entity, ppos);
4103                                         }
4104                                 }
4105                         }
4106
4107                         prev_decl->modifiers |= decl->modifiers;
4108                         if (entity->kind == ENTITY_FUNCTION) {
4109                                 previous_entity->function.is_inline |= entity->function.is_inline;
4110                         }
4111                         return previous_entity;
4112                 }
4113
4114                 warning_t why;
4115                 if (is_warn_on(why = WARN_SHADOW) ||
4116                     (is_warn_on(why = WARN_SHADOW_LOCAL) && previous_entity->base.parent_scope != file_scope)) {
4117                         char const *const what = get_entity_kind_name(previous_entity->kind);
4118                         warningf(why, pos, "'%N' shadows %s (declared %P)", entity, what, ppos);
4119                 }
4120         }
4121
4122         if (entity->kind == ENTITY_FUNCTION) {
4123                 if (is_definition &&
4124                                 entity->declaration.storage_class != STORAGE_CLASS_STATIC &&
4125                                 !is_main(entity)) {
4126                         if (is_warn_on(WARN_MISSING_PROTOTYPES)) {
4127                                 warningf(WARN_MISSING_PROTOTYPES, pos, "no previous prototype for '%#N'", entity);
4128                         } else {
4129                                 goto warn_missing_declaration;
4130                         }
4131                 }
4132         } else if (entity->kind == ENTITY_VARIABLE) {
4133                 if (current_scope                     == file_scope &&
4134                                 entity->declaration.storage_class == STORAGE_CLASS_NONE &&
4135                                 !entity->declaration.implicit) {
4136 warn_missing_declaration:
4137                         warningf(WARN_MISSING_DECLARATIONS, pos, "no previous declaration for '%#N'", entity);
4138                 }
4139         }
4140
4141 finish:
4142         environment_push(entity);
4143         append_entity(current_scope, entity);
4144
4145         return entity;
4146 }
4147
4148 static void parser_error_multiple_definition(entity_t *entity,
4149                                              const position_t *pos)
4150 {
4151         errorf(pos, "redefinition of '%N' (declared %P)", entity, &entity->base.pos);
4152 }
4153
4154 static bool is_declaration_specifier(const token_t *token)
4155 {
4156         switch (token->kind) {
4157                 DECLARATION_START
4158                         return true;
4159                 case T_IDENTIFIER:
4160                         return is_typedef_symbol(token->base.symbol);
4161
4162                 default:
4163                         return false;
4164         }
4165 }
4166
4167 static void parse_init_declarator_rest(entity_t *entity)
4168 {
4169         type_t *orig_type = type_error_type;
4170
4171         if (entity->base.kind == ENTITY_TYPEDEF) {
4172                 position_t const *const pos = &entity->base.pos;
4173                 errorf(pos, "'%N' is initialized (use __typeof__ instead)", entity);
4174         } else {
4175                 assert(is_declaration(entity));
4176                 orig_type = entity->declaration.type;
4177         }
4178
4179         type_t *type = skip_typeref(orig_type);
4180
4181         if (entity->kind == ENTITY_VARIABLE
4182                         && entity->variable.initializer != NULL) {
4183                 parser_error_multiple_definition(entity, HERE);
4184         }
4185         eat('=');
4186
4187         declaration_t *const declaration = &entity->declaration;
4188         bool must_be_constant = false;
4189         if (declaration->storage_class == STORAGE_CLASS_STATIC ||
4190             entity->base.parent_scope  == file_scope) {
4191                 must_be_constant = true;
4192         }
4193
4194         if (is_type_function(type)) {
4195                 position_t const *const pos = &entity->base.pos;
4196                 errorf(pos, "'%N' is initialized like a variable", entity);
4197                 orig_type = type_error_type;
4198         }
4199
4200         parse_initializer_env_t env;
4201         env.type             = orig_type;
4202         env.must_be_constant = must_be_constant;
4203         env.entity           = entity;
4204
4205         initializer_t *initializer = parse_initializer(&env);
4206
4207         if (entity->kind == ENTITY_VARIABLE) {
4208                 /* §6.7.5:22  array initializers for arrays with unknown size
4209                  * determine the array type size */
4210                 declaration->type            = env.type;
4211                 entity->variable.initializer = initializer;
4212         }
4213 }
4214
4215 /* parse rest of a declaration without any declarator */
4216 static void parse_anonymous_declaration_rest(
4217                 const declaration_specifiers_t *specifiers)
4218 {
4219         eat(';');
4220         anonymous_entity = NULL;
4221
4222         position_t const *const pos = &specifiers->pos;
4223         if (specifiers->storage_class != STORAGE_CLASS_NONE ||
4224                         specifiers->thread_local) {
4225                 warningf(WARN_OTHER, pos, "useless storage class in empty declaration");
4226         }
4227
4228         type_t *type = specifiers->type;
4229         switch (type->kind) {
4230                 case TYPE_COMPOUND_STRUCT:
4231                 case TYPE_COMPOUND_UNION: {
4232                         if (type->compound.compound->base.symbol == NULL) {
4233                                 warningf(WARN_OTHER, pos, "unnamed struct/union that defines no instances");
4234                         }
4235                         break;
4236                 }
4237
4238                 case TYPE_ENUM:
4239                         break;
4240
4241                 default:
4242                         warningf(WARN_OTHER, pos, "empty declaration");
4243                         break;
4244         }
4245 }
4246
4247 static void check_variable_type_complete(entity_t *ent)
4248 {
4249         if (ent->kind != ENTITY_VARIABLE)
4250                 return;
4251
4252         /* §6.7:7  If an identifier for an object is declared with no linkage, the
4253          *         type for the object shall be complete [...] */
4254         declaration_t *decl = &ent->declaration;
4255         if (decl->storage_class == STORAGE_CLASS_EXTERN ||
4256                         decl->storage_class == STORAGE_CLASS_STATIC)
4257                 return;
4258
4259         type_t *const type = skip_typeref(decl->type);
4260         if (!is_type_incomplete(type))
4261                 return;
4262
4263         /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
4264          * are given length one. */
4265         if (is_type_array(type) && ent->base.parent_scope == file_scope) {
4266                 ARR_APP1(declaration_t*, incomplete_arrays, decl);
4267                 return;
4268         }
4269
4270         errorf(&ent->base.pos, "variable '%#N' has incomplete type", ent);
4271 }
4272
4273
4274 static void parse_declaration_rest(entity_t *ndeclaration,
4275                 const declaration_specifiers_t *specifiers,
4276                 parsed_declaration_func         finished_declaration,
4277                 declarator_flags_t              flags)
4278 {
4279         add_anchor_token(';');
4280         add_anchor_token(',');
4281         while (true) {
4282                 entity_t *entity = finished_declaration(ndeclaration, token.kind == '=');
4283
4284                 if (token.kind == '=') {
4285                         parse_init_declarator_rest(entity);
4286                 } else if (entity->kind == ENTITY_VARIABLE) {
4287                         /* ISO/IEC 14882:1998(E) §8.5.3:3  The initializer can be omitted
4288                          * [...] where the extern specifier is explicitly used. */
4289                         declaration_t *decl = &entity->declaration;
4290                         if (decl->storage_class != STORAGE_CLASS_EXTERN &&
4291                             is_type_reference(skip_typeref(decl->type))) {
4292                                 position_t const *const pos = &entity->base.pos;
4293                                 errorf(pos, "reference '%#N' must be initialized", entity);
4294                         }
4295                 }
4296
4297                 check_variable_type_complete(entity);
4298
4299                 if (!accept(','))
4300                         break;
4301
4302                 add_anchor_token('=');
4303                 ndeclaration = parse_declarator(specifiers, flags);
4304                 rem_anchor_token('=');
4305         }
4306         rem_anchor_token(',');
4307         rem_anchor_token(';');
4308         expect(';');
4309
4310         anonymous_entity = NULL;
4311 }
4312
4313 static entity_t *finished_kr_declaration(entity_t *entity, bool is_definition)
4314 {
4315         symbol_t *symbol = entity->base.symbol;
4316         if (symbol == NULL)
4317                 return entity;
4318
4319         assert(entity->base.namespc == NAMESPACE_NORMAL);
4320         entity_t *previous_entity = get_entity(symbol, NAMESPACE_NORMAL);
4321         if (previous_entity == NULL
4322                         || previous_entity->base.parent_scope != current_scope) {
4323                 errorf(&entity->base.pos, "expected declaration of a function parameter, found '%Y'",
4324                        symbol);
4325                 return entity;
4326         }
4327
4328         if (is_definition) {
4329                 errorf(HERE, "'%N' is initialised", entity);
4330         }
4331
4332         return record_entity(entity, false);
4333 }
4334
4335 static void parse_declaration(parsed_declaration_func finished_declaration,
4336                               declarator_flags_t      flags)
4337 {
4338         add_anchor_token(';');
4339         declaration_specifiers_t specifiers;
4340         parse_declaration_specifiers(&specifiers);
4341         rem_anchor_token(';');
4342
4343         if (token.kind == ';') {
4344                 parse_anonymous_declaration_rest(&specifiers);
4345         } else {
4346                 entity_t *entity = parse_declarator(&specifiers, flags);
4347                 parse_declaration_rest(entity, &specifiers, finished_declaration, flags);
4348         }
4349 }
4350
4351 /* §6.5.2.2:6 */
4352 static type_t *get_default_promoted_type(type_t *orig_type)
4353 {
4354         type_t *result = orig_type;
4355
4356         type_t *type = skip_typeref(orig_type);
4357         if (is_type_integer(type)) {
4358                 result = promote_integer(type);
4359         } else if (is_type_atomic(type, ATOMIC_TYPE_FLOAT)) {
4360                 result = type_double;
4361         }
4362
4363         return result;
4364 }
4365
4366 static void parse_kr_declaration_list(entity_t *entity)
4367 {
4368         if (entity->kind != ENTITY_FUNCTION)
4369                 return;
4370
4371         type_t *type = skip_typeref(entity->declaration.type);
4372         assert(is_type_function(type));
4373         if (!type->function.kr_style_parameters)
4374                 return;
4375
4376         add_anchor_token('{');
4377
4378         PUSH_SCOPE(&entity->function.parameters);
4379
4380         entity_t *parameter = entity->function.parameters.entities;
4381         for ( ; parameter != NULL; parameter = parameter->base.next) {
4382                 assert(parameter->base.parent_scope == NULL);
4383                 parameter->base.parent_scope = current_scope;
4384                 environment_push(parameter);
4385         }
4386
4387         /* parse declaration list */
4388         for (;;) {
4389                 switch (token.kind) {
4390                         DECLARATION_START
4391                         /* This covers symbols, which are no type, too, and results in
4392                          * better error messages.  The typical cases are misspelled type
4393                          * names and missing includes. */
4394                         case T_IDENTIFIER:
4395                                 parse_declaration(finished_kr_declaration, DECL_IS_PARAMETER);
4396                                 break;
4397                         default:
4398                                 goto decl_list_end;
4399                 }
4400         }
4401 decl_list_end:
4402
4403         POP_SCOPE();
4404
4405         /* update function type */
4406         type_t *new_type = duplicate_type(type);
4407
4408         function_parameter_t  *parameters = NULL;
4409         function_parameter_t **anchor     = &parameters;
4410
4411         /* did we have an earlier prototype? */
4412         entity_t *proto_type = get_entity(entity->base.symbol, NAMESPACE_NORMAL);
4413         if (proto_type != NULL && proto_type->kind != ENTITY_FUNCTION)
4414                 proto_type = NULL;
4415
4416         function_parameter_t *proto_parameter = NULL;
4417         if (proto_type != NULL) {
4418                 type_t *proto_type_type = proto_type->declaration.type;
4419                 proto_parameter         = proto_type_type->function.parameters;
4420                 /* If a K&R function definition has a variadic prototype earlier, then
4421                  * make the function definition variadic, too. This should conform to
4422                  * §6.7.5.3:15 and §6.9.1:8. */
4423                 new_type->function.variadic = proto_type_type->function.variadic;
4424         } else {
4425                 /* §6.9.1.7: A K&R style parameter list does NOT act as a function
4426                  * prototype */
4427                 new_type->function.unspecified_parameters = true;
4428         }
4429
4430         bool need_incompatible_warning = false;
4431         parameter = entity->function.parameters.entities;
4432         for (; parameter != NULL; parameter = parameter->base.next,
4433                         proto_parameter =
4434                                 proto_parameter == NULL ? NULL : proto_parameter->next) {
4435                 if (parameter->kind != ENTITY_PARAMETER)
4436                         continue;
4437
4438                 type_t *parameter_type = parameter->declaration.type;
4439                 if (parameter_type == NULL) {
4440                         position_t const* const pos = &parameter->base.pos;
4441                         if (strict_mode) {
4442                                 errorf(pos, "no type specified for function '%N'", parameter);
4443                                 parameter_type = type_error_type;
4444                         } else {
4445                                 warningf(WARN_IMPLICIT_INT, pos, "no type specified for function parameter '%N', using 'int'", parameter);
4446                                 parameter_type = type_int;
4447                         }
4448                         parameter->declaration.type = parameter_type;
4449                 }
4450
4451                 semantic_parameter_incomplete(parameter);
4452
4453                 /* we need the default promoted types for the function type */
4454                 type_t *not_promoted = parameter_type;
4455                 parameter_type       = get_default_promoted_type(parameter_type);
4456
4457                 /* gcc special: if the type of the prototype matches the unpromoted
4458                  * type don't promote */
4459                 if (!strict_mode && proto_parameter != NULL) {
4460                         type_t *proto_p_type = skip_typeref(proto_parameter->type);
4461                         type_t *promo_skip   = skip_typeref(parameter_type);
4462                         type_t *param_skip   = skip_typeref(not_promoted);
4463                         if (!types_compatible(proto_p_type, promo_skip)
4464                                 && types_compatible(proto_p_type, param_skip)) {
4465                                 /* don't promote */
4466                                 need_incompatible_warning = true;
4467                                 parameter_type = not_promoted;
4468                         }
4469                 }
4470                 function_parameter_t *const function_parameter
4471                         = allocate_parameter(parameter_type);
4472
4473                 *anchor = function_parameter;
4474                 anchor  = &function_parameter->next;
4475         }
4476
4477         new_type->function.parameters = parameters;
4478         new_type = identify_new_type(new_type);
4479
4480         if (need_incompatible_warning) {
4481                 symbol_t   const *const sym  = entity->base.symbol;
4482                 position_t const *const pos  = &entity->base.pos;
4483                 position_t const *const ppos = &proto_type->base.pos;
4484                 warningf(WARN_OTHER, pos, "declaration '%#N' is incompatible with '%#T' (declared %P)", proto_type, new_type, sym, ppos);
4485         }
4486         entity->declaration.type = new_type;
4487
4488         rem_anchor_token('{');
4489 }
4490
4491 static bool first_err = true;
4492
4493 /**
4494  * When called with first_err set, prints the name of the current function,
4495  * else does noting.
4496  */
4497 static void print_in_function(void)
4498 {
4499         if (first_err) {
4500                 first_err = false;
4501                 char const *const file = current_function->base.base.pos.input_name;
4502                 diagnosticf("%s: In '%N':\n", file, (entity_t const*)current_function);
4503         }
4504 }
4505
4506 /**
4507  * Check if all labels are defined in the current function.
4508  * Check if all labels are used in the current function.
4509  */
4510 static void check_labels(void)
4511 {
4512         for (const goto_statement_t *goto_statement = goto_first;
4513             goto_statement != NULL;
4514             goto_statement = goto_statement->next) {
4515                 label_t *label = goto_statement->label;
4516                 if (label->base.pos.input_name == NULL) {
4517                         print_in_function();
4518                         position_t const *const pos = &goto_statement->base.pos;
4519                         errorf(pos, "'%N' used but not defined", (entity_t const*)label);
4520                  }
4521         }
4522
4523         if (is_warn_on(WARN_UNUSED_LABEL)) {
4524                 for (const label_statement_t *label_statement = label_first;
4525                          label_statement != NULL;
4526                          label_statement = label_statement->next) {
4527                         label_t *label = label_statement->label;
4528
4529                         if (! label->used) {
4530                                 print_in_function();
4531                                 position_t const *const pos = &label_statement->base.pos;
4532                                 warningf(WARN_UNUSED_LABEL, pos, "'%N' defined but not used", (entity_t const*)label);
4533                         }
4534                 }
4535         }
4536 }
4537
4538 static void warn_unused_entity(warning_t const why, entity_t *entity, entity_t *const last)
4539 {
4540         entity_t const *const end = last != NULL ? last->base.next : NULL;
4541         for (; entity != end; entity = entity->base.next) {
4542                 if (!is_declaration(entity))
4543                         continue;
4544
4545                 declaration_t *declaration = &entity->declaration;
4546                 if (declaration->implicit)
4547                         continue;
4548
4549                 if (!declaration->used) {
4550                         print_in_function();
4551                         warningf(why, &entity->base.pos, "'%N' is unused", entity);
4552                 } else if (entity->kind == ENTITY_VARIABLE && !entity->variable.read) {
4553                         print_in_function();
4554                         warningf(why, &entity->base.pos, "'%N' is never read", entity);
4555                 }
4556         }
4557 }
4558
4559 static void check_unused_variables(statement_t *const stmt, void *const env)
4560 {
4561         (void)env;
4562
4563         switch (stmt->kind) {
4564                 case STATEMENT_DECLARATION: {
4565                         declaration_statement_t const *const decls = &stmt->declaration;
4566                         warn_unused_entity(WARN_UNUSED_VARIABLE, decls->declarations_begin, decls->declarations_end);
4567                         return;
4568                 }
4569
4570                 case STATEMENT_FOR:
4571                         warn_unused_entity(WARN_UNUSED_VARIABLE, stmt->fors.scope.entities, NULL);
4572                         return;
4573
4574                 default:
4575                         return;
4576         }
4577 }
4578
4579 /**
4580  * Check declarations of current_function for unused entities.
4581  */
4582 static void check_declarations(void)
4583 {
4584         if (is_warn_on(WARN_UNUSED_PARAMETER)) {
4585                 const scope_t *scope = &current_function->parameters;
4586                 warn_unused_entity(WARN_UNUSED_PARAMETER, scope->entities, NULL);
4587         }
4588         if (is_warn_on(WARN_UNUSED_VARIABLE)) {
4589                 walk_statements(current_function->body, check_unused_variables, NULL);
4590         }
4591 }
4592
4593 static int determine_truth(expression_t const* const cond)
4594 {
4595         return
4596                 is_constant_expression(cond) != EXPR_CLASS_CONSTANT ? 0 :
4597                 fold_constant_to_bool(cond)                         ? 1 :
4598                 -1;
4599 }
4600
4601 static void check_reachable(statement_t *);
4602 static bool reaches_end;
4603
4604 static bool expression_returns(expression_t const *const expr)
4605 {
4606         switch (expr->kind) {
4607                 case EXPR_CALL: {
4608                         expression_t const *const func = expr->call.function;
4609                         type_t       const *const type = skip_typeref(func->base.type);
4610                         if (type->kind == TYPE_POINTER) {
4611                                 type_t const *const points_to
4612                                         = skip_typeref(type->pointer.points_to);
4613                                 if (points_to->kind == TYPE_FUNCTION
4614                                     && points_to->function.modifiers & DM_NORETURN)
4615                                         return false;
4616                         }
4617
4618                         if (!expression_returns(func))
4619                                 return false;
4620
4621                         for (call_argument_t const* arg = expr->call.arguments; arg != NULL; arg = arg->next) {
4622                                 if (!expression_returns(arg->expression))
4623                                         return false;
4624                         }
4625
4626                         return true;
4627                 }
4628
4629                 case EXPR_REFERENCE:
4630                 case EXPR_ENUM_CONSTANT:
4631                 case EXPR_LITERAL_CASES:
4632                 case EXPR_LITERAL_CHARACTER:
4633                 case EXPR_STRING_LITERAL:
4634                 case EXPR_COMPOUND_LITERAL: // TODO descend into initialisers
4635                 case EXPR_LABEL_ADDRESS:
4636                 case EXPR_CLASSIFY_TYPE:
4637                 case EXPR_SIZEOF: // TODO handle obscure VLA case
4638                 case EXPR_ALIGNOF:
4639                 case EXPR_FUNCNAME:
4640                 case EXPR_BUILTIN_CONSTANT_P:
4641                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P:
4642                 case EXPR_OFFSETOF:
4643                 case EXPR_ERROR:
4644                         return true;
4645
4646                 case EXPR_STATEMENT: {
4647                         bool old_reaches_end = reaches_end;
4648                         reaches_end = false;
4649                         check_reachable(expr->statement.statement);
4650                         bool returns = reaches_end;
4651                         reaches_end = old_reaches_end;
4652                         return returns;
4653                 }
4654
4655                 case EXPR_CONDITIONAL:
4656                         // TODO handle constant expression
4657
4658                         if (!expression_returns(expr->conditional.condition))
4659                                 return false;
4660
4661                         if (expr->conditional.true_expression != NULL
4662                                         && expression_returns(expr->conditional.true_expression))
4663                                 return true;
4664
4665                         return expression_returns(expr->conditional.false_expression);
4666
4667                 case EXPR_SELECT:
4668                         return expression_returns(expr->select.compound);
4669
4670                 case EXPR_ARRAY_ACCESS:
4671                         return
4672                                 expression_returns(expr->array_access.array_ref) &&
4673                                 expression_returns(expr->array_access.index);
4674
4675                 case EXPR_VA_START:
4676                         return expression_returns(expr->va_starte.ap);
4677
4678                 case EXPR_VA_ARG:
4679                         return expression_returns(expr->va_arge.ap);
4680
4681                 case EXPR_VA_COPY:
4682                         return expression_returns(expr->va_copye.src);
4683
4684                 case EXPR_UNARY_CASES_MANDATORY:
4685                         return expression_returns(expr->unary.value);
4686
4687                 case EXPR_UNARY_THROW:
4688                         return false;
4689
4690                 case EXPR_BINARY_CASES:
4691                         // TODO handle constant lhs of && and ||
4692                         return
4693                                 expression_returns(expr->binary.left) &&
4694                                 expression_returns(expr->binary.right);
4695         }
4696
4697         panic("unhandled expression");
4698 }
4699
4700 static bool initializer_returns(initializer_t const *const init)
4701 {
4702         switch (init->kind) {
4703                 case INITIALIZER_VALUE:
4704                         return expression_returns(init->value.value);
4705
4706                 case INITIALIZER_LIST: {
4707                         initializer_t * const*       i       = init->list.initializers;
4708                         initializer_t * const* const end     = i + init->list.len;
4709                         bool                         returns = true;
4710                         for (; i != end; ++i) {
4711                                 if (!initializer_returns(*i))
4712                                         returns = false;
4713                         }
4714                         return returns;
4715                 }
4716
4717                 case INITIALIZER_STRING:
4718                 case INITIALIZER_DESIGNATOR: // designators have no payload
4719                         return true;
4720         }
4721         panic("unhandled initializer");
4722 }
4723
4724 static bool noreturn_candidate;
4725
4726 static void check_reachable(statement_t *const stmt)
4727 {
4728         if (stmt->base.reachable)
4729                 return;
4730         if (stmt->kind != STATEMENT_DO_WHILE)
4731                 stmt->base.reachable = true;
4732
4733         statement_t *last = stmt;
4734         statement_t *next;
4735         switch (stmt->kind) {
4736                 case STATEMENT_ERROR:
4737                 case STATEMENT_EMPTY:
4738                 case STATEMENT_ASM:
4739                         next = stmt->base.next;
4740                         break;
4741
4742                 case STATEMENT_DECLARATION: {
4743                         declaration_statement_t const *const decl = &stmt->declaration;
4744                         entity_t                const *      ent  = decl->declarations_begin;
4745                         entity_t                const *const last_decl = decl->declarations_end;
4746                         if (ent != NULL) {
4747                                 for (;; ent = ent->base.next) {
4748                                         if (ent->kind                 == ENTITY_VARIABLE &&
4749                                             ent->variable.initializer != NULL            &&
4750                                             !initializer_returns(ent->variable.initializer)) {
4751                                                 return;
4752                                         }
4753                                         if (ent == last_decl)
4754                                                 break;
4755                                 }
4756                         }
4757                         next = stmt->base.next;
4758                         break;
4759                 }
4760
4761                 case STATEMENT_COMPOUND:
4762                         next = stmt->compound.statements;
4763                         if (next == NULL)
4764                                 next = stmt->base.next;
4765                         break;
4766
4767                 case STATEMENT_RETURN: {
4768                         expression_t const *const val = stmt->returns.value;
4769                         if (val == NULL || expression_returns(val))
4770                                 noreturn_candidate = false;
4771                         return;
4772                 }
4773
4774                 case STATEMENT_IF: {
4775                         if_statement_t const *const ifs  = &stmt->ifs;
4776                         expression_t   const *const cond = ifs->condition;
4777
4778                         if (!expression_returns(cond))
4779                                 return;
4780
4781                         int const val = determine_truth(cond);
4782
4783                         if (val >= 0)
4784                                 check_reachable(ifs->true_statement);
4785
4786                         if (val > 0)
4787                                 return;
4788
4789                         if (ifs->false_statement != NULL) {
4790                                 check_reachable(ifs->false_statement);
4791                                 return;
4792                         }
4793
4794                         next = stmt->base.next;
4795                         break;
4796                 }
4797
4798                 case STATEMENT_SWITCH: {
4799                         switch_statement_t const *const switchs = &stmt->switchs;
4800                         expression_t       const *const expr    = switchs->expression;
4801
4802                         if (!expression_returns(expr))
4803                                 return;
4804
4805                         if (is_constant_expression(expr) == EXPR_CLASS_CONSTANT) {
4806                                 ir_tarval              *const val      = fold_constant_to_tarval(expr);
4807                                 case_label_statement_t *      defaults = NULL;
4808                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4809                                         if (i->expression == NULL) {
4810                                                 defaults = i;
4811                                                 continue;
4812                                         }
4813
4814                                         if (i->first_case == val || i->last_case == val ||
4815                                                 ((tarval_cmp(i->first_case, val) & ir_relation_less_equal)
4816                                             && (tarval_cmp(val, i->last_case) & ir_relation_less_equal))) {
4817                                                 check_reachable((statement_t*)i);
4818                                                 return;
4819                                         }
4820                                 }
4821
4822                                 if (defaults != NULL) {
4823                                         check_reachable((statement_t*)defaults);
4824                                         return;
4825                                 }
4826                         } else {
4827                                 bool has_default = false;
4828                                 for (case_label_statement_t *i = switchs->first_case; i != NULL; i = i->next) {
4829                                         if (i->expression == NULL)
4830                                                 has_default = true;
4831
4832                                         check_reachable((statement_t*)i);
4833                                 }
4834
4835                                 if (has_default)
4836                                         return;
4837                         }
4838
4839                         next = stmt->base.next;
4840                         break;
4841                 }
4842
4843                 case STATEMENT_EXPRESSION: {
4844                         /* Check for noreturn function call */
4845                         expression_t const *const expr = stmt->expression.expression;
4846                         if (!expression_returns(expr))
4847                                 return;
4848
4849                         next = stmt->base.next;
4850                         break;
4851                 }
4852
4853                 case STATEMENT_CONTINUE:
4854                         for (statement_t *parent = stmt;;) {
4855                                 parent = parent->base.parent;
4856                                 if (parent == NULL) /* continue not within loop */
4857                                         return;
4858
4859                                 next = parent;
4860                                 switch (parent->kind) {
4861                                         case STATEMENT_DO_WHILE: goto continue_do_while;
4862                                         case STATEMENT_FOR:      goto continue_for;
4863
4864                                         default: break;
4865                                 }
4866                         }
4867
4868                 case STATEMENT_BREAK:
4869                         for (statement_t *parent = stmt;;) {
4870                                 parent = parent->base.parent;
4871                                 if (parent == NULL) /* break not within loop/switch */
4872                                         return;
4873
4874                                 switch (parent->kind) {
4875                                         case STATEMENT_SWITCH:
4876                                         case STATEMENT_DO_WHILE:
4877                                         case STATEMENT_FOR:
4878                                                 last = parent;
4879                                                 next = parent->base.next;
4880                                                 goto found_break_parent;
4881
4882                                         default: break;
4883                                 }
4884                         }
4885 found_break_parent:
4886                         break;
4887
4888                 case STATEMENT_COMPUTED_GOTO: {
4889                         if (!expression_returns(stmt->computed_goto.expression))
4890                                 return;
4891
4892                         statement_t *parent = stmt->base.parent;
4893                         if (parent == NULL) /* top level goto */
4894                                 return;
4895                         next = parent;
4896                         break;
4897                 }
4898
4899                 case STATEMENT_GOTO:
4900                         next = stmt->gotos.label->statement;
4901                         if (next == NULL) /* missing label */
4902                                 return;
4903                         break;
4904
4905                 case STATEMENT_LABEL:
4906                         next = stmt->label.statement;
4907                         break;
4908
4909                 case STATEMENT_CASE_LABEL:
4910                         next = stmt->case_label.statement;
4911                         break;
4912
4913                 case STATEMENT_DO_WHILE:
4914                         next = stmt->do_while.body;
4915                         break;
4916
4917                 case STATEMENT_FOR: {
4918                         for_statement_t *const fors = &stmt->fors;
4919
4920                         if (fors->condition_reachable)
4921                                 return;
4922                         fors->condition_reachable = true;
4923
4924                         expression_t const *const cond = fors->condition;
4925
4926                         int val;
4927                         if (cond == NULL) {
4928                                 val = 1;
4929                         } else if (expression_returns(cond)) {
4930                                 val = determine_truth(cond);
4931                         } else {
4932                                 return;
4933                         }
4934
4935                         if (val >= 0)
4936                                 check_reachable(fors->body);
4937
4938                         if (val > 0)
4939                                 return;
4940
4941                         next = stmt->base.next;
4942                         break;
4943                 }
4944
4945                 case STATEMENT_MS_TRY: {
4946                         ms_try_statement_t const *const ms_try = &stmt->ms_try;
4947                         check_reachable(ms_try->try_statement);
4948                         next = ms_try->final_statement;
4949                         break;
4950                 }
4951
4952                 case STATEMENT_LEAVE: {
4953                         statement_t *parent = stmt;
4954                         for (;;) {
4955                                 parent = parent->base.parent;
4956                                 if (parent == NULL) /* __leave not within __try */
4957                                         return;
4958
4959                                 if (parent->kind == STATEMENT_MS_TRY) {
4960                                         last = parent;
4961                                         next = parent->ms_try.final_statement;
4962                                         break;
4963                                 }
4964                         }
4965                         break;
4966                 }
4967
4968                 default:
4969                         panic("invalid statement kind");
4970         }
4971
4972         while (next == NULL) {
4973                 next = last->base.parent;
4974                 if (next == NULL) {
4975                         noreturn_candidate = false;
4976
4977                         type_t *const type = skip_typeref(current_function->base.type);
4978                         assert(is_type_function(type));
4979                         type_t *const ret  = skip_typeref(type->function.return_type);
4980                         if (!is_type_void(ret) &&
4981                             is_type_valid(ret) &&
4982                             !is_main(current_entity)) {
4983                                 position_t const *const pos = &stmt->base.pos;
4984                                 warningf(WARN_RETURN_TYPE, pos, "control reaches end of non-void function");
4985                         }
4986                         return;
4987                 }
4988
4989                 switch (next->kind) {
4990                         case STATEMENT_ERROR:
4991                         case STATEMENT_EMPTY:
4992                         case STATEMENT_DECLARATION:
4993                         case STATEMENT_EXPRESSION:
4994                         case STATEMENT_ASM:
4995                         case STATEMENT_RETURN:
4996                         case STATEMENT_CONTINUE:
4997                         case STATEMENT_BREAK:
4998                         case STATEMENT_COMPUTED_GOTO:
4999                         case STATEMENT_GOTO:
5000                         case STATEMENT_LEAVE:
5001                                 panic("invalid control flow in function");
5002
5003                         case STATEMENT_COMPOUND:
5004                                 if (next->compound.stmt_expr) {
5005                                         reaches_end = true;
5006                                         return;
5007                                 }
5008                                 /* FALLTHROUGH */
5009                         case STATEMENT_IF:
5010                         case STATEMENT_SWITCH:
5011                         case STATEMENT_LABEL:
5012                         case STATEMENT_CASE_LABEL:
5013                                 last = next;
5014                                 next = next->base.next;
5015                                 break;
5016
5017                         case STATEMENT_DO_WHILE: {
5018 continue_do_while:
5019                                 if (next->base.reachable)
5020                                         return;
5021                                 next->base.reachable = true;
5022
5023                                 do_while_statement_t const *const dw   = &next->do_while;
5024                                 expression_t         const *const cond = dw->condition;
5025
5026                                 if (!expression_returns(cond))
5027                                         return;
5028
5029                                 int const val = determine_truth(cond);
5030
5031                                 if (val >= 0)
5032                                         check_reachable(dw->body);
5033
5034                                 if (val > 0)
5035                                         return;
5036
5037                                 last = next;
5038                                 next = next->base.next;
5039                                 break;
5040                         }
5041
5042                         case STATEMENT_FOR: {
5043 continue_for:;
5044                                 for_statement_t *const fors = &next->fors;
5045
5046                                 fors->step_reachable = true;
5047
5048                                 if (fors->condition_reachable)
5049                                         return;
5050                                 fors->condition_reachable = true;
5051
5052                                 expression_t const *const cond = fors->condition;
5053
5054                                 int val;
5055                                 if (cond == NULL) {
5056                                         val = 1;
5057                                 } else if (expression_returns(cond)) {
5058                                         val = determine_truth(cond);
5059                                 } else {
5060                                         return;
5061                                 }
5062
5063                                 if (val >= 0)
5064                                         check_reachable(fors->body);
5065
5066                                 if (val > 0)
5067                                         return;
5068
5069                                 last = next;
5070                                 next = next->base.next;
5071                                 break;
5072                         }
5073
5074                         case STATEMENT_MS_TRY:
5075                                 last = next;
5076                                 next = next->ms_try.final_statement;
5077                                 break;
5078                 }
5079         }
5080
5081         check_reachable(next);
5082 }
5083
5084 static void check_unreachable(statement_t* const stmt, void *const env)
5085 {
5086         (void)env;
5087
5088         switch (stmt->kind) {
5089                 case STATEMENT_DO_WHILE:
5090                         if (!stmt->base.reachable) {
5091                                 expression_t const *const cond = stmt->do_while.condition;
5092                                 if (determine_truth(cond) >= 0) {
5093                                         position_t const *const pos = &cond->base.pos;
5094                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of do-while-loop is unreachable");
5095                                 }
5096                         }
5097                         return;
5098
5099                 case STATEMENT_FOR: {
5100                         for_statement_t const* const fors = &stmt->fors;
5101
5102                         // if init and step are unreachable, cond is unreachable, too
5103                         if (!stmt->base.reachable && !fors->step_reachable) {
5104                                 goto warn_unreachable;
5105                         } else {
5106                                 if (!stmt->base.reachable && fors->initialisation != NULL) {
5107                                         position_t const *const pos = &fors->initialisation->base.pos;
5108                                         warningf(WARN_UNREACHABLE_CODE, pos, "initialisation of for-statement is unreachable");
5109                                 }
5110
5111                                 if (!fors->condition_reachable && fors->condition != NULL) {
5112                                         position_t const *const pos = &fors->condition->base.pos;
5113                                         warningf(WARN_UNREACHABLE_CODE, pos, "condition of for-statement is unreachable");
5114                                 }
5115
5116                                 if (!fors->step_reachable && fors->step != NULL) {
5117                                         position_t const *const pos = &fors->step->base.pos;
5118                                         warningf(WARN_UNREACHABLE_CODE, pos, "step of for-statement is unreachable");
5119                                 }
5120                         }
5121                         return;
5122                 }
5123
5124                 case STATEMENT_COMPOUND:
5125                         if (stmt->compound.statements != NULL)
5126                                 return;
5127                         goto warn_unreachable;
5128
5129                 case STATEMENT_DECLARATION: {
5130                         /* Only warn if there is at least one declarator with an initializer.
5131                          * This typically occurs in switch statements. */
5132                         declaration_statement_t const *const decl = &stmt->declaration;
5133                         entity_t                const *      ent  = decl->declarations_begin;
5134                         entity_t                const *const last = decl->declarations_end;
5135                         if (ent != NULL) {
5136                                 for (;; ent = ent->base.next) {
5137                                         if (ent->kind                 == ENTITY_VARIABLE &&
5138                                                         ent->variable.initializer != NULL) {
5139                                                 goto warn_unreachable;
5140                                         }
5141                                         if (ent == last)
5142                                                 return;
5143                                 }
5144                         }
5145                 }
5146
5147                 default:
5148 warn_unreachable:
5149                         if (!stmt->base.reachable) {
5150                                 position_t const *const pos = &stmt->base.pos;
5151                                 warningf(WARN_UNREACHABLE_CODE, pos, "statement is unreachable");
5152                         }
5153                         return;
5154         }
5155 }
5156
5157 static bool is_main(entity_t *entity)
5158 {
5159         static symbol_t *sym_main = NULL;
5160         if (sym_main == NULL) {
5161                 sym_main = symbol_table_insert("main");
5162         }
5163
5164         if (entity->base.symbol != sym_main)
5165                 return false;
5166         /* must be in outermost scope */
5167         if (entity->base.parent_scope != file_scope)
5168                 return false;
5169
5170         return true;
5171 }
5172
5173 static void prepare_main_collect2(entity_t*);
5174
5175 static void parse_external_declaration(void)
5176 {
5177         /* function-definitions and declarations both start with declaration
5178          * specifiers */
5179         add_anchor_token(';');
5180         declaration_specifiers_t specifiers;
5181         parse_declaration_specifiers(&specifiers);
5182         rem_anchor_token(';');
5183
5184         /* must be a declaration */
5185         if (token.kind == ';') {
5186                 parse_anonymous_declaration_rest(&specifiers);
5187                 return;
5188         }
5189
5190         add_anchor_token(',');
5191         add_anchor_token('=');
5192         add_anchor_token(';');
5193         add_anchor_token('{');
5194
5195         /* declarator is common to both function-definitions and declarations */
5196         entity_t *ndeclaration = parse_declarator(&specifiers, DECL_FLAGS_NONE);
5197
5198         rem_anchor_token('{');
5199         rem_anchor_token(';');
5200         rem_anchor_token('=');
5201         rem_anchor_token(',');
5202
5203         /* must be a declaration */
5204         switch (token.kind) {
5205                 case ',':
5206                 case ';':
5207                 case '=':
5208                         parse_declaration_rest(ndeclaration, &specifiers, record_entity,
5209                                         DECL_FLAGS_NONE);
5210                         return;
5211         }
5212
5213         /* must be a function definition */
5214         parse_kr_declaration_list(ndeclaration);
5215
5216         if (token.kind != '{') {
5217                 parse_error_expected("while parsing function definition", '{', NULL);
5218                 eat_until_matching_token(';');
5219                 return;
5220         }
5221
5222         assert(is_declaration(ndeclaration));
5223         type_t *const orig_type = ndeclaration->declaration.type;
5224         type_t *      type      = skip_typeref(orig_type);
5225
5226         if (!is_type_function(type)) {
5227                 if (is_type_valid(type)) {
5228                         errorf(HERE, "declarator '%#N' has a body but is not a function type", ndeclaration);
5229                 }
5230                 eat_block();
5231                 return;
5232         }
5233
5234         position_t const *const pos = &ndeclaration->base.pos;
5235         if (is_typeref(orig_type)) {
5236                 /* §6.9.1:2 */
5237                 errorf(pos, "type of function definition '%#N' is a typedef", ndeclaration);
5238         }
5239
5240         if (is_type_compound(skip_typeref(type->function.return_type))) {
5241                 warningf(WARN_AGGREGATE_RETURN, pos, "'%N' returns an aggregate", ndeclaration);
5242         }
5243         if (type->function.unspecified_parameters) {
5244                 warningf(WARN_OLD_STYLE_DEFINITION, pos, "old-style definition of '%N'", ndeclaration);
5245         } else {
5246                 warningf(WARN_TRADITIONAL, pos, "traditional C rejects ISO C style definition of '%N'", ndeclaration);
5247         }
5248
5249         /* §6.7.5.3:14 a function definition with () means no
5250          * parameters (and not unspecified parameters) */
5251         if (type->function.unspecified_parameters &&
5252                         type->function.parameters == NULL) {
5253                 type_t *copy                          = duplicate_type(type);
5254                 copy->function.unspecified_parameters = false;
5255                 type                                  = identify_new_type(copy);
5256
5257                 ndeclaration->declaration.type = type;
5258         }
5259
5260         entity_t *const entity = record_entity(ndeclaration, true);
5261         assert(entity->kind == ENTITY_FUNCTION);
5262         assert(ndeclaration->kind == ENTITY_FUNCTION);
5263
5264         function_t *const function = &entity->function;
5265         if (ndeclaration != entity) {
5266                 function->parameters = ndeclaration->function.parameters;
5267         }
5268
5269         PUSH_SCOPE(&function->parameters);
5270
5271         entity_t *parameter = function->parameters.entities;
5272         for (; parameter != NULL; parameter = parameter->base.next) {
5273                 if (parameter->base.parent_scope == &ndeclaration->function.parameters) {
5274                         parameter->base.parent_scope = current_scope;
5275                 }
5276                 assert(parameter->base.parent_scope == NULL
5277                                 || parameter->base.parent_scope == current_scope);
5278                 parameter->base.parent_scope = current_scope;
5279                 if (parameter->base.symbol == NULL) {
5280                         errorf(&parameter->base.pos, "parameter name omitted");
5281                         continue;
5282                 }
5283                 environment_push(parameter);
5284         }
5285
5286         if (function->body != NULL) {
5287                 parser_error_multiple_definition(entity, HERE);
5288                 eat_block();
5289         } else {
5290                 /* parse function body */
5291                 int         label_stack_top      = label_top();
5292                 function_t *old_current_function = current_function;
5293                 current_function                 = function;
5294                 PUSH_CURRENT_ENTITY(entity);
5295                 PUSH_PARENT(NULL);
5296
5297                 goto_first   = NULL;
5298                 goto_anchor  = &goto_first;
5299                 label_first  = NULL;
5300                 label_anchor = &label_first;
5301
5302                 statement_t *const body = parse_compound_statement(false);
5303                 function->body = body;
5304                 first_err = true;
5305                 check_labels();
5306                 check_declarations();
5307                 if (is_warn_on(WARN_RETURN_TYPE)      ||
5308                     is_warn_on(WARN_UNREACHABLE_CODE) ||
5309                     (is_warn_on(WARN_MISSING_NORETURN) && !(function->base.modifiers & DM_NORETURN))) {
5310                         noreturn_candidate = true;
5311                         check_reachable(body);
5312                         if (is_warn_on(WARN_UNREACHABLE_CODE))
5313                                 walk_statements(body, check_unreachable, NULL);
5314                         if (noreturn_candidate &&
5315                             !(function->base.modifiers & DM_NORETURN)) {
5316                                 position_t const *const pos = &body->base.pos;
5317                                 warningf(WARN_MISSING_NORETURN, pos, "function '%#N' is candidate for attribute 'noreturn'", entity);
5318                         }
5319                 }
5320
5321                 if (is_main(entity)) {
5322                         /* Force main to C linkage. */
5323                         type_t *const type = entity->declaration.type;
5324                         assert(is_type_function(type));
5325                         if (type->function.linkage != LINKAGE_C) {
5326                                 type_t *new_type           = duplicate_type(type);
5327                                 new_type->function.linkage = LINKAGE_C;
5328                                 entity->declaration.type   = identify_new_type(new_type);
5329                         }
5330
5331                         if (enable_main_collect2_hack)
5332                                 prepare_main_collect2(entity);
5333                 }
5334
5335                 POP_CURRENT_ENTITY();
5336                 POP_PARENT();
5337                 assert(current_function == function);
5338                 current_function = old_current_function;
5339                 label_pop_to(label_stack_top);
5340         }
5341
5342         POP_SCOPE();
5343 }
5344
5345 static entity_t *find_compound_entry(compound_t *compound, symbol_t *symbol)
5346 {
5347         entity_t *iter = compound->members.entities;
5348         for (; iter != NULL; iter = iter->base.next) {
5349                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5350                         continue;
5351
5352                 if (iter->base.symbol == symbol) {
5353                         return iter;
5354                 } else if (iter->base.symbol == NULL) {
5355                         /* search in anonymous structs and unions */
5356                         type_t *type = skip_typeref(iter->declaration.type);
5357                         if (is_type_compound(type)) {
5358                                 if (find_compound_entry(type->compound.compound, symbol)
5359                                                 != NULL)
5360                                         return iter;
5361                         }
5362                         continue;
5363                 }
5364         }
5365
5366         return NULL;
5367 }
5368
5369 static void check_deprecated(const position_t *pos, const entity_t *entity)
5370 {
5371         if (!is_declaration(entity))
5372                 return;
5373         if ((entity->declaration.modifiers & DM_DEPRECATED) == 0)
5374                 return;
5375
5376         position_t const *const epos = &entity->base.pos;
5377         char       const *const msg  = get_deprecated_string(entity->declaration.attributes);
5378         if (msg != NULL) {
5379                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P): \"%s\"", entity, epos, msg);
5380         } else {
5381                 warningf(WARN_DEPRECATED_DECLARATIONS, pos, "'%N' is deprecated (declared %P)", entity, epos);
5382         }
5383 }
5384
5385
5386 static expression_t *create_select(const position_t *pos, expression_t *addr,
5387                                    type_qualifiers_t qualifiers,
5388                                                                    entity_t *entry)
5389 {
5390         assert(entry->kind == ENTITY_COMPOUND_MEMBER);
5391
5392         check_deprecated(pos, entry);
5393
5394         expression_t *select          = allocate_expression_zero(EXPR_SELECT);
5395         select->select.compound       = addr;
5396         select->select.compound_entry = entry;
5397
5398         type_t *entry_type = entry->declaration.type;
5399         type_t *res_type   = get_qualified_type(entry_type, qualifiers);
5400
5401         /* bitfields need special treatment */
5402         if (entry->compound_member.bitfield) {
5403                 unsigned bit_size = entry->compound_member.bit_size;
5404                 /* if fewer bits than an int, convert to int (see §6.3.1.1) */
5405                 if (bit_size < get_atomic_type_size(ATOMIC_TYPE_INT) * BITS_PER_BYTE) {
5406                         res_type = type_int;
5407                 }
5408         }
5409
5410         /* we always do the auto-type conversions; the & and sizeof parser contains
5411          * code to revert this! */
5412         select->base.type = automatic_type_conversion(res_type);
5413
5414
5415         return select;
5416 }
5417
5418 /**
5419  * Find entry with symbol in compound. Search anonymous structs and unions and
5420  * creates implicit select expressions for them.
5421  * Returns the adress for the innermost compound.
5422  */
5423 static expression_t *find_create_select(const position_t *pos,
5424                                         expression_t *addr,
5425                                         type_qualifiers_t qualifiers,
5426                                         compound_t *compound, symbol_t *symbol)
5427 {
5428         entity_t *iter = compound->members.entities;
5429         for (; iter != NULL; iter = iter->base.next) {
5430                 if (iter->kind != ENTITY_COMPOUND_MEMBER)
5431                         continue;
5432
5433                 symbol_t *iter_symbol = iter->base.symbol;
5434                 if (iter_symbol == NULL) {
5435                         type_t *type = iter->declaration.type;
5436                         if (!is_type_compound(type))
5437                                 continue;
5438
5439                         compound_t *sub_compound = type->compound.compound;
5440
5441                         if (find_compound_entry(sub_compound, symbol) == NULL)
5442                                 continue;
5443
5444                         expression_t *sub_addr = create_select(pos, addr, qualifiers, iter);
5445                         sub_addr->base.pos      = *pos;
5446                         sub_addr->base.implicit = true;
5447                         return find_create_select(pos, sub_addr, qualifiers, sub_compound,
5448                                                   symbol);
5449                 }
5450
5451                 if (iter_symbol == symbol) {
5452                         return create_select(pos, addr, qualifiers, iter);
5453                 }
5454         }
5455
5456         return NULL;
5457 }
5458
5459 static void parse_bitfield_member(entity_t *entity)
5460 {
5461         eat(':');
5462
5463         expression_t *size = parse_constant_expression();
5464         long          size_long;
5465
5466         assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5467         type_t *type = entity->declaration.type;
5468         if (!is_type_integer(skip_typeref(type))) {
5469                 errorf(HERE, "bitfield base type '%T' is not an integer type",
5470                            type);
5471         }
5472
5473         if (is_constant_expression(size) != EXPR_CLASS_CONSTANT) {
5474                 /* error already reported by parse_constant_expression */
5475                 size_long = get_type_size(type) * 8;
5476         } else {
5477                 size_long = fold_constant_to_int(size);
5478
5479                 const symbol_t *symbol = entity->base.symbol;
5480                 const symbol_t *user_symbol
5481                         = symbol == NULL ? sym_anonymous : symbol;
5482                 unsigned bit_size = get_type_size(type) * 8;
5483                 if (size_long < 0) {
5484                         errorf(HERE, "negative width in bit-field '%Y'", user_symbol);
5485                 } else if (size_long == 0 && symbol != NULL) {
5486                         errorf(HERE, "zero width for bit-field '%Y'", user_symbol);
5487                 } else if (bit_size > 0 && (unsigned)size_long > bit_size) {
5488                         errorf(HERE, "width of bitfield '%Y' exceeds its type",
5489                                    user_symbol);
5490                 } else {
5491                         /* hope that people don't invent crazy types with more bits
5492                          * than our struct can hold */
5493                         assert(size_long <
5494                                    (1 << sizeof(entity->compound_member.bit_size)*8));
5495                 }
5496         }
5497
5498         entity->compound_member.bitfield = true;
5499         entity->compound_member.bit_size = (unsigned char)size_long;
5500 }
5501
5502 static void parse_compound_declarators(compound_t *compound,
5503                 const declaration_specifiers_t *specifiers)
5504 {
5505         add_anchor_token(';');
5506         add_anchor_token(',');
5507         do {
5508                 entity_t *entity;
5509
5510                 if (token.kind == ':') {
5511                         /* anonymous bitfield */
5512                         type_t *type = specifiers->type;
5513                         entity_t *const entity = allocate_entity_zero(ENTITY_COMPOUND_MEMBER, NAMESPACE_NORMAL, NULL, HERE);
5514                         entity->declaration.declared_storage_class = STORAGE_CLASS_NONE;
5515                         entity->declaration.storage_class          = STORAGE_CLASS_NONE;
5516                         entity->declaration.type                   = type;
5517
5518                         parse_bitfield_member(entity);
5519
5520                         attribute_t  *attributes = parse_attributes(NULL);
5521                         attribute_t **anchor     = &attributes;
5522                         while (*anchor != NULL)
5523                                 anchor = &(*anchor)->next;
5524                         *anchor = specifiers->attributes;
5525                         if (attributes != NULL) {
5526                                 handle_entity_attributes(attributes, entity);
5527                         }
5528                         entity->declaration.attributes = attributes;
5529
5530                         append_entity(&compound->members, entity);
5531                 } else {
5532                         entity = parse_declarator(specifiers,
5533                                         DECL_MAY_BE_ABSTRACT | DECL_CREATE_COMPOUND_MEMBER);
5534                         position_t const *const pos = &entity->base.pos;
5535                         if (entity->kind == ENTITY_TYPEDEF) {
5536                                 errorf(pos, "typedef not allowed as compound member");
5537                         } else {
5538                                 assert(entity->kind == ENTITY_COMPOUND_MEMBER);
5539
5540                                 /* make sure we don't define a symbol multiple times */
5541                                 symbol_t *symbol = entity->base.symbol;
5542                                 if (symbol != NULL) {
5543                                         entity_t *prev = find_compound_entry(compound, symbol);
5544                                         if (prev != NULL) {
5545                                                 position_t const *const ppos = &prev->base.pos;
5546                                                 errorf(pos, "multiple declarations of '%N' (declared %P)", entity, ppos);
5547                                         }
5548                                 }
5549
5550                                 if (token.kind == ':') {
5551                                         parse_bitfield_member(entity);
5552
5553                                         attribute_t *attributes = parse_attributes(NULL);
5554                                         handle_entity_attributes(attributes, entity);
5555                                 } else {
5556                                         type_t *orig_type = entity->declaration.type;
5557                                         type_t *type      = skip_typeref(orig_type);
5558                                         if (is_type_function(type)) {
5559                                                 errorf(pos, "'%N' must not have function type '%T'", entity, orig_type);
5560                                         } else if (is_type_incomplete(type)) {
5561                                                 /* §6.7.2.1:16 flexible array member */
5562                                                 if (!is_type_array(type)       ||
5563                                                                 token.kind          != ';' ||
5564                                                                 look_ahead(1)->kind != '}') {
5565                                                         errorf(pos, "'%N' has incomplete type '%T'", entity, orig_type);
5566                                                 } else if (compound->members.entities == NULL) {
5567                                                         errorf(pos, "flexible array member in otherwise empty struct");
5568                                                 }
5569                                         }
5570                                 }
5571
5572                                 append_entity(&compound->members, entity);
5573                         }
5574                 }
5575         } while (accept(','));
5576         rem_anchor_token(',');
5577         rem_anchor_token(';');
5578         expect(';');
5579
5580         anonymous_entity = NULL;
5581 }
5582
5583 static void parse_compound_type_entries(compound_t *compound)
5584 {
5585         eat('{');
5586         add_anchor_token('}');
5587
5588         for (;;) {
5589                 switch (token.kind) {
5590                         DECLARATION_START
5591                         case T___extension__:
5592                         case T_IDENTIFIER: {
5593                                 PUSH_EXTENSION();
5594                                 declaration_specifiers_t specifiers;
5595                                 parse_declaration_specifiers(&specifiers);
5596                                 parse_compound_declarators(compound, &specifiers);
5597                                 POP_EXTENSION();
5598                                 break;
5599                         }
5600
5601                         default:
5602                                 rem_anchor_token('}');
5603                                 expect('}');
5604                                 /* §6.7.2.1:7 */
5605                                 compound->complete = true;
5606                                 return;
5607                 }
5608         }
5609 }
5610
5611 static type_t *parse_typename(void)
5612 {
5613         declaration_specifiers_t specifiers;
5614         parse_declaration_specifiers(&specifiers);
5615         if (specifiers.storage_class != STORAGE_CLASS_NONE
5616                         || specifiers.thread_local) {
5617                 /* TODO: improve error message, user does probably not know what a
5618                  * storage class is...
5619                  */
5620                 errorf(&specifiers.pos, "typename must not have a storage class");
5621         }
5622
5623         type_t *result = parse_abstract_declarator(specifiers.type);
5624
5625         return result;
5626 }
5627
5628
5629
5630
5631 typedef expression_t* (*parse_expression_function)(void);
5632 typedef expression_t* (*parse_expression_infix_function)(expression_t *left);
5633
5634 typedef struct expression_parser_function_t expression_parser_function_t;
5635 struct expression_parser_function_t {
5636         parse_expression_function        parser;
5637         precedence_t                     infix_precedence;
5638         parse_expression_infix_function  infix_parser;
5639 };
5640
5641 static expression_parser_function_t expression_parsers[T_LAST_TOKEN];
5642
5643 static type_t *get_string_type(string_encoding_t const enc)
5644 {
5645         bool const warn = is_warn_on(WARN_WRITE_STRINGS);
5646         switch (enc) {
5647         case STRING_ENCODING_CHAR:
5648         case STRING_ENCODING_UTF8:   return warn ? type_const_char_ptr     : type_char_ptr;
5649         case STRING_ENCODING_CHAR16: return warn ? type_char16_t_const_ptr : type_char16_t_ptr;
5650         case STRING_ENCODING_CHAR32: return warn ? type_char32_t_const_ptr : type_char32_t_ptr;
5651         case STRING_ENCODING_WIDE:   return warn ? type_const_wchar_t_ptr  : type_wchar_t_ptr;
5652         }
5653         panic("invalid string encoding");
5654 }
5655
5656 /**
5657  * Parse a string constant.
5658  */
5659 static expression_t *parse_string_literal(void)
5660 {
5661         expression_t *const expr = allocate_expression_zero(EXPR_STRING_LITERAL);
5662         expr->string_literal.value = concat_string_literals();
5663         expr->base.type            = get_string_type(expr->string_literal.value.encoding);
5664         return expr;
5665 }
5666
5667 /**
5668  * Parse a boolean constant.
5669  */
5670 static expression_t *parse_boolean_literal(bool value)
5671 {
5672         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_BOOLEAN);
5673         literal->base.type           = type_bool;
5674         literal->literal.value.begin = value ? "true" : "false";
5675         literal->literal.value.size  = value ? 4 : 5;
5676
5677         eat(value ? T_true : T_false);
5678         return literal;
5679 }
5680
5681 static void warn_traditional_suffix(char const *const suffix)
5682 {
5683         warningf(WARN_TRADITIONAL, HERE, "traditional C rejects the '%s' suffix", suffix);
5684 }
5685
5686 static void check_integer_suffix(expression_t *const expr, char const *const suffix)
5687 {
5688         unsigned     spec = SPECIFIER_NONE;
5689         char const  *c    = suffix;
5690         for (;;) {
5691                 specifiers_t add;
5692                 if (*c == 'L' || *c == 'l') {
5693                         add = SPECIFIER_LONG;
5694                         if (*c == c[1]) {
5695                                 add |= SPECIFIER_LONG_LONG;
5696                                 ++c;
5697                         }
5698                 } else if (*c == 'U' || *c == 'u') {
5699                         add = SPECIFIER_UNSIGNED;
5700                 } else {
5701                         break;
5702                 }
5703                 ++c;
5704                 if (spec & add)
5705                         goto error;
5706                 spec |= add;
5707         }
5708
5709         if (*c == '\0') {
5710                 type_t *type;
5711                 switch (spec) {
5712                 case SPECIFIER_NONE:                                            type = type_int;                break;
5713                 case                      SPECIFIER_LONG:                       type = type_long;               break;
5714                 case                      SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_long_long;          break;
5715                 case SPECIFIER_UNSIGNED:                                        type = type_unsigned_int;       break;
5716                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG:                       type = type_unsigned_long;      break;
5717                 case SPECIFIER_UNSIGNED | SPECIFIER_LONG | SPECIFIER_LONG_LONG: type = type_unsigned_long_long; break;
5718                 default: panic("inconsistent suffix");
5719                 }
5720                 if (spec != SPECIFIER_NONE && spec != SPECIFIER_LONG) {
5721                         warn_traditional_suffix(suffix);
5722                 }
5723                 expr->base.type = type;
5724                 /* Integer type depends on the size of the number and the size
5725                  * representable by the types. The backend/codegeneration has to
5726                  * determine that. */
5727                 determine_literal_type(&expr->literal);
5728         } else {
5729 error:
5730                 errorf(HERE, "invalid suffix '%s' on integer constant", suffix);
5731         }
5732 }
5733
5734 static void check_floatingpoint_suffix(expression_t *const expr, char const *const suffix)
5735 {
5736         type_t     *type;
5737         char const *c    = suffix;
5738         switch (*c) {
5739         case 'F':
5740         case 'f': type = type_float;       ++c; break;
5741         case 'L':
5742         case 'l': type = type_long_double; ++c; break;
5743         default:  type = type_double;           break;
5744         }
5745
5746         if (*c == '\0') {
5747                 expr->base.type = type;
5748                 if (suffix[0] != '\0') {
5749                         warn_traditional_suffix(suffix);
5750                 }
5751         } else {
5752                 errorf(HERE, "invalid suffix '%s' on floatingpoint constant", suffix);
5753         }
5754 }
5755
5756 static expression_t *parse_number_literal(void)
5757 {
5758         string_t const *const str      = &token.literal.string;
5759         char     const *      i        = str->begin;
5760         unsigned              digits   = 0;
5761         bool                  is_float = false;
5762
5763         /* Parse base prefix. */
5764         unsigned base;
5765         if (*i == '0') {
5766                 switch (*++i) {
5767                 case 'B': case 'b': base =  2; ++i;               break;
5768                 case 'X': case 'x': base = 16; ++i;               break;
5769                 default:            base =  8; digits |= 1U << 0; break;
5770                 }
5771         } else {
5772                 base = 10;
5773         }
5774
5775         /* Parse mantissa. */
5776         for (;; ++i) {
5777                 unsigned digit;
5778                 switch (*i) {
5779                 case '.':
5780                         if (is_float) {
5781                                 errorf(HERE, "multiple decimal points in %K", &token);
5782                                 i = 0;
5783                                 goto done;
5784                         }
5785                         is_float = true;
5786                         if (base == 8)
5787                                 base = 10;
5788                         continue;
5789
5790                 case '0':           digit =  0; break;
5791                 case '1':           digit =  1; break;
5792                 case '2':           digit =  2; break;
5793                 case '3':           digit =  3; break;
5794                 case '4':           digit =  4; break;
5795                 case '5':           digit =  5; break;
5796                 case '6':           digit =  6; break;
5797                 case '7':           digit =  7; break;
5798                 case '8':           digit =  8; break;
5799                 case '9':           digit =  9; break;
5800                 case 'A': case 'a': digit = 10; break;
5801                 case 'B': case 'b': digit = 11; break;
5802                 case 'C': case 'c': digit = 12; break;
5803                 case 'D': case 'd': digit = 13; break;
5804                 case 'E': case 'e': digit = 14; break;
5805                 case 'F': case 'f': digit = 15; break;
5806
5807                 default: goto done_mantissa;
5808                 }
5809
5810                 if (digit >= 10 && base != 16)
5811                         goto done_mantissa;
5812
5813                 digits |= 1U << digit;
5814         }
5815 done_mantissa:
5816
5817         /* Parse exponent. */
5818         switch (base) {
5819         case 2:
5820                 if (is_float)
5821                         errorf(HERE, "binary floating %K not allowed", &token);
5822                 break;
5823
5824         case  8:
5825         case 10:
5826                 if (*i == 'E' || *i == 'e') {
5827                         base = 10;
5828                         goto parse_exponent;
5829                 }
5830                 break;
5831
5832         case 16:
5833                 if (*i == 'P' || *i == 'p') {
5834 parse_exponent:
5835                         ++i;
5836                         is_float = true;
5837
5838                         if (*i == '-' || *i == '+')
5839                                 ++i;
5840
5841                         if (isdigit(*i)) {
5842                                 do {
5843                                         ++i;
5844                                 } while (isdigit(*i));
5845                         } else {
5846                                 errorf(HERE, "exponent of %K has no digits", &token);
5847                         }
5848                 } else if (is_float) {
5849                         errorf(HERE, "hexadecimal floating %K requires an exponent", &token);
5850                         i = 0;
5851                 }
5852                 break;
5853
5854         default:
5855                 panic("invalid base");
5856         }
5857
5858 done:;
5859         expression_t *const expr = allocate_expression_zero(is_float ? EXPR_LITERAL_FLOATINGPOINT : EXPR_LITERAL_INTEGER);
5860         expr->literal.value = *str;
5861
5862         if (i) {
5863                 if (digits == 0) {
5864                         errorf(HERE, "%K has no digits", &token);
5865                 } else if (digits & ~((1U << base) - 1)) {
5866                         errorf(HERE, "invalid digit in %K", &token);
5867                 } else {
5868                         expr->literal.suffix = i;
5869                         if (is_float) {
5870                                 check_floatingpoint_suffix(expr, i);
5871                         } else {
5872                                 check_integer_suffix(expr, i);
5873                         }
5874                 }
5875         }
5876
5877         eat(T_NUMBER);
5878         return expr;
5879 }
5880
5881 /**
5882  * Parse a character constant.
5883  */
5884 static expression_t *parse_character_constant(void)
5885 {
5886         expression_t *const literal = allocate_expression_zero(EXPR_LITERAL_CHARACTER);
5887         literal->string_literal.value = token.literal.string;
5888
5889         size_t const size = get_string_len(&token.literal.string);
5890         switch (token.literal.string.encoding) {
5891         case STRING_ENCODING_CHAR:
5892         case STRING_ENCODING_UTF8:
5893                 literal->base.type = c_mode & _CXX ? type_char : type_int;
5894                 if (size > 1) {
5895                         if (!GNU_MODE && !(c_mode & _C99)) {
5896                                 errorf(HERE, "more than 1 character in character constant");
5897                         } else {
5898                                 literal->base.type = type_int;
5899                                 warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5900                         }
5901                 }
5902                 break;
5903
5904         case STRING_ENCODING_CHAR16: literal->base.type = type_char16_t; goto warn_multi;
5905         case STRING_ENCODING_CHAR32: literal->base.type = type_char32_t; goto warn_multi;
5906         case STRING_ENCODING_WIDE:   literal->base.type = type_wchar_t;  goto warn_multi;
5907 warn_multi:
5908                 if (size > 1) {
5909                         warningf(WARN_MULTICHAR, HERE, "multi-character character constant");
5910                 }
5911                 break;
5912         }
5913
5914         eat(T_CHARACTER_CONSTANT);
5915         return literal;
5916 }
5917
5918 static entity_t *create_implicit_function(symbol_t *symbol, position_t const *const pos)
5919 {
5920         type_t *ntype                          = allocate_type_zero(TYPE_FUNCTION);
5921         ntype->function.return_type            = type_int;
5922         ntype->function.unspecified_parameters = true;
5923         ntype->function.linkage                = LINKAGE_C;
5924         type_t *type                           = identify_new_type(ntype);
5925
5926         entity_t *const entity = allocate_entity_zero(ENTITY_FUNCTION, NAMESPACE_NORMAL, symbol, pos);
5927         entity->declaration.storage_class          = STORAGE_CLASS_EXTERN;
5928         entity->declaration.declared_storage_class = STORAGE_CLASS_EXTERN;
5929         entity->declaration.type                   = type;
5930         entity->declaration.implicit               = true;
5931
5932         if (current_scope != NULL)
5933                 record_entity(entity, false);
5934
5935         return entity;
5936 }
5937
5938 /**
5939  * Performs automatic type cast as described in §6.3.2.1.
5940  *
5941  * @param orig_type  the original type
5942  */
5943 static type_t *automatic_type_conversion(type_t *orig_type)
5944 {
5945         type_t *type = skip_typeref(orig_type);
5946         if (is_type_array(type)) {
5947                 array_type_t *array_type   = &type->array;
5948                 type_t       *element_type = array_type->element_type;
5949                 unsigned      qualifiers   = array_type->base.qualifiers;
5950
5951                 return make_pointer_type(element_type, qualifiers);
5952         }
5953
5954         if (is_type_function(type)) {
5955                 return make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
5956         }
5957
5958         return orig_type;
5959 }
5960
5961 /**
5962  * reverts the automatic casts of array to pointer types and function
5963  * to function-pointer types as defined §6.3.2.1
5964  */
5965 type_t *revert_automatic_type_conversion(const expression_t *expression)
5966 {
5967         switch (expression->kind) {
5968         case EXPR_REFERENCE: {
5969                 entity_t *entity = expression->reference.entity;
5970                 if (is_declaration(entity)) {
5971                         return entity->declaration.type;
5972                 } else if (entity->kind == ENTITY_ENUM_VALUE) {
5973                         return entity->enum_value.enum_type;
5974                 } else {
5975                         panic("no declaration or enum in reference");
5976                 }
5977         }
5978
5979         case EXPR_SELECT: {
5980                 entity_t *entity = expression->select.compound_entry;
5981                 assert(is_declaration(entity));
5982                 type_t   *type   = entity->declaration.type;
5983                 return get_qualified_type(type, expression->base.type->base.qualifiers);
5984         }
5985
5986         case EXPR_UNARY_DEREFERENCE: {
5987                 const expression_t *const value = expression->unary.value;
5988                 type_t             *const type  = skip_typeref(value->base.type);
5989                 if (!is_type_pointer(type))
5990                         return type_error_type;
5991                 return type->pointer.points_to;
5992         }
5993
5994         case EXPR_ARRAY_ACCESS: {
5995                 const expression_t *array_ref = expression->array_access.array_ref;
5996                 type_t             *type_left = skip_typeref(array_ref->base.type);
5997                 if (!is_type_pointer(type_left))
5998                         return type_error_type;
5999                 return type_left->pointer.points_to;
6000         }
6001
6002         case EXPR_STRING_LITERAL: {
6003                 size_t  const size = get_string_len(&expression->string_literal.value) + 1;
6004                 type_t *const elem = get_unqualified_type(expression->base.type->pointer.points_to);
6005                 return make_array_type(elem, size, TYPE_QUALIFIER_NONE);
6006         }
6007
6008         case EXPR_COMPOUND_LITERAL:
6009                 return expression->compound_literal.type;
6010
6011         default:
6012                 break;
6013         }
6014         return expression->base.type;
6015 }
6016
6017 /**
6018  * Find an entity matching a symbol in a scope.
6019  * Uses current scope if scope is NULL
6020  */
6021 static entity_t *lookup_entity(const scope_t *scope, symbol_t *symbol,
6022                                namespace_tag_t namespc)
6023 {
6024         if (scope == NULL) {
6025                 return get_entity(symbol, namespc);
6026         }
6027
6028         /* we should optimize here, if scope grows above a certain size we should
6029            construct a hashmap here... */
6030         entity_t *entity = scope->entities;
6031         for ( ; entity != NULL; entity = entity->base.next) {
6032                 if (entity->base.symbol == symbol
6033                     && (namespace_tag_t)entity->base.namespc == namespc)
6034                         break;
6035         }
6036
6037         return entity;
6038 }
6039
6040 static entity_t *parse_qualified_identifier(void)
6041 {
6042         /* namespace containing the symbol */
6043         symbol_t      *symbol;
6044         position_t     pos;
6045         const scope_t *lookup_scope = NULL;
6046
6047         if (accept(T_COLONCOLON))
6048                 lookup_scope = &unit->scope;
6049
6050         entity_t *entity;
6051         while (true) {
6052                 symbol = expect_identifier("while parsing identifier", &pos);
6053                 if (!symbol)
6054                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6055
6056                 /* lookup entity */
6057                 entity = lookup_entity(lookup_scope, symbol, NAMESPACE_NORMAL);
6058
6059                 if (!accept(T_COLONCOLON))
6060                         break;
6061
6062                 switch (entity->kind) {
6063                 case ENTITY_NAMESPACE:
6064                         lookup_scope = &entity->namespacee.members;
6065                         break;
6066                 case ENTITY_STRUCT:
6067                 case ENTITY_UNION:
6068                 case ENTITY_CLASS:
6069                         lookup_scope = &entity->compound.members;
6070                         break;
6071                 default:
6072                         errorf(&pos, "'%Y' must be a namespace, class, struct or union (but is a %s)",
6073                                symbol, get_entity_kind_name(entity->kind));
6074
6075                         /* skip further qualifications */
6076                         while (accept(T_IDENTIFIER) && accept(T_COLONCOLON)) {}
6077
6078                         return create_error_entity(sym_anonymous, ENTITY_VARIABLE);
6079                 }
6080         }
6081
6082         if (entity == NULL) {
6083                 if (!strict_mode && token.kind == '(') {
6084                         /* an implicitly declared function */
6085                         entity = create_implicit_function(symbol, &pos);
6086                         warningf(WARN_IMPLICIT_FUNCTION_DECLARATION, &pos, "implicit declaration of '%N'", entity);
6087                 } else {
6088                         errorf(&pos, "unknown identifier '%Y' found.", symbol);
6089                         entity = create_error_entity(symbol, ENTITY_VARIABLE);
6090                 }
6091         }
6092
6093         return entity;
6094 }
6095
6096 static expression_t *parse_reference(void)
6097 {
6098         position_t const pos    = *HERE;
6099         entity_t  *const entity = parse_qualified_identifier();
6100
6101         type_t *orig_type;
6102         if (is_declaration(entity)) {
6103                 orig_type = entity->declaration.type;
6104         } else if (entity->kind == ENTITY_ENUM_VALUE) {
6105                 orig_type = entity->enum_value.enum_type;
6106         } else {
6107                 panic("expected declaration or enum value in reference");
6108         }
6109
6110         /* we always do the auto-type conversions; the & and sizeof parser contains
6111          * code to revert this! */
6112         type_t *type = automatic_type_conversion(orig_type);
6113
6114         expression_kind_t kind = EXPR_REFERENCE;
6115         if (entity->kind == ENTITY_ENUM_VALUE)
6116                 kind = EXPR_ENUM_CONSTANT;
6117
6118         expression_t *expression     = allocate_expression_zero(kind);
6119         expression->base.pos         = pos;
6120         expression->base.type        = type;
6121         expression->reference.entity = entity;
6122
6123         /* this declaration is used */
6124         if (is_declaration(entity)) {
6125                 entity->declaration.used = true;
6126         }
6127
6128         if (entity->base.parent_scope != file_scope
6129                 && (current_function != NULL
6130                         && entity->base.parent_scope->depth < current_function->parameters.depth)
6131                 && (entity->kind == ENTITY_VARIABLE || entity->kind == ENTITY_PARAMETER)) {
6132                 /* access of a variable from an outer function */
6133                 entity->variable.address_taken = true;
6134                 current_function->need_closure = true;
6135         }
6136
6137         check_deprecated(&pos, entity);
6138
6139         return expression;
6140 }
6141
6142 static bool semantic_cast(expression_t *cast)
6143 {
6144         expression_t     *expression      = cast->unary.value;
6145         type_t           *orig_dest_type  = cast->base.type;
6146         type_t           *orig_type_right = expression->base.type;
6147         type_t     const *dst_type        = skip_typeref(orig_dest_type);
6148         type_t     const *src_type        = skip_typeref(orig_type_right);
6149         position_t const *pos             = &cast->base.pos;
6150
6151         /* §6.5.4 A (void) cast is explicitly permitted, more for documentation than for utility. */
6152         if (is_type_void(dst_type))
6153                 return true;
6154
6155         /* only integer and pointer can be casted to pointer */
6156         if (is_type_pointer(dst_type)  &&
6157             !is_type_pointer(src_type) &&
6158             !is_type_integer(src_type) &&
6159             is_type_valid(src_type)) {
6160                 errorf(pos, "cannot convert type '%T' to a pointer type", orig_type_right);
6161                 return false;
6162         }
6163
6164         if (!is_type_scalar(dst_type) && is_type_valid(dst_type)) {
6165                 errorf(pos, "conversion to non-scalar type '%T' requested", orig_dest_type);
6166                 return false;
6167         }
6168
6169         if (!is_type_scalar(src_type) && is_type_valid(src_type)) {
6170                 errorf(pos, "conversion from non-scalar type '%T' requested", orig_type_right);
6171                 return false;
6172         }
6173
6174         if (is_type_pointer(src_type) && is_type_pointer(dst_type)) {
6175                 type_t *src = skip_typeref(src_type->pointer.points_to);
6176                 type_t *dst = skip_typeref(dst_type->pointer.points_to);
6177                 unsigned missing_qualifiers =
6178                         src->base.qualifiers & ~dst->base.qualifiers;
6179                 if (missing_qualifiers != 0) {
6180                         warningf(WARN_CAST_QUAL, pos, "cast discards qualifiers '%Q' in pointer target type of '%T'", missing_qualifiers, orig_type_right);
6181                 }
6182         }
6183         return true;
6184 }
6185
6186 static expression_t *parse_compound_literal(position_t const *const pos,
6187                                             type_t *type)
6188 {
6189         expression_t *expression = allocate_expression_zero(EXPR_COMPOUND_LITERAL);
6190         expression->base.pos = *pos;
6191         bool global_scope = current_scope == file_scope;
6192
6193         parse_initializer_env_t env;
6194         env.type             = type;
6195         env.entity           = NULL;
6196         env.must_be_constant = global_scope;
6197         initializer_t *initializer = parse_initializer(&env);
6198         type = env.type;
6199
6200         expression->base.type                     = automatic_type_conversion(type);
6201         expression->compound_literal.initializer  = initializer;
6202         expression->compound_literal.type         = type;
6203         expression->compound_literal.global_scope = global_scope;
6204
6205         return expression;
6206 }
6207
6208 /**
6209  * Parse a cast expression.
6210  */
6211 static expression_t *parse_cast(void)
6212 {
6213         position_t const pos = *HERE;
6214
6215         eat('(');
6216         add_anchor_token(')');
6217
6218         type_t *type = parse_typename();
6219
6220         rem_anchor_token(')');
6221         expect(')');
6222
6223         if (token.kind == '{') {
6224                 return parse_compound_literal(&pos, type);
6225         }
6226
6227         expression_t *cast = allocate_expression_zero(EXPR_UNARY_CAST);
6228         cast->base.pos     = pos;
6229
6230         expression_t *value = parse_subexpression(PREC_CAST);
6231         cast->base.type   = type;
6232         cast->unary.value = value;
6233
6234         if (! semantic_cast(cast)) {
6235                 /* TODO: record the error in the AST. else it is impossible to detect it */
6236         }
6237
6238         return cast;
6239 }
6240
6241 /**
6242  * Parse a statement expression.
6243  */
6244 static expression_t *parse_statement_expression(void)
6245 {
6246         expression_t *expression = allocate_expression_zero(EXPR_STATEMENT);
6247
6248         eat('(');
6249         add_anchor_token(')');
6250
6251         statement_t *statement          = parse_compound_statement(true);
6252         statement->compound.stmt_expr   = true;
6253         expression->statement.statement = statement;
6254
6255         /* find last statement and use its type */
6256         type_t *type = type_void;
6257         const statement_t *stmt = statement->compound.statements;
6258         if (stmt != NULL) {
6259                 while (stmt->base.next != NULL)
6260                         stmt = stmt->base.next;
6261
6262                 if (stmt->kind == STATEMENT_EXPRESSION) {
6263                         type = stmt->expression.expression->base.type;
6264                 }
6265         } else {
6266                 position_t const *const pos = &expression->base.pos;
6267                 warningf(WARN_OTHER, pos, "empty statement expression ({})");
6268         }
6269         expression->base.type = type;
6270
6271         rem_anchor_token(')');
6272         expect(')');
6273         return expression;
6274 }
6275
6276 /**
6277  * Parse a parenthesized expression.
6278  */
6279 static expression_t *parse_parenthesized_expression(void)
6280 {
6281         token_t const* const la1 = look_ahead(1);
6282         switch (la1->kind) {
6283         case '{':
6284                 /* gcc extension: a statement expression */
6285                 return parse_statement_expression();
6286
6287         case T_IDENTIFIER:
6288                 if (is_typedef_symbol(la1->base.symbol)) {
6289         DECLARATION_START
6290                         return parse_cast();
6291                 }
6292         }
6293
6294         eat('(');
6295         add_anchor_token(')');
6296         expression_t *result = parse_expression();
6297         result->base.parenthesized = true;
6298         rem_anchor_token(')');
6299         expect(')');
6300
6301         return result;
6302 }
6303
6304 static expression_t *parse_function_keyword(funcname_kind_t const kind)
6305 {
6306         if (current_function == NULL) {
6307                 errorf(HERE, "%K used outside of a function", &token);
6308         }
6309
6310         expression_t *expression  = allocate_expression_zero(EXPR_FUNCNAME);
6311         expression->base.type     = type_char_ptr;
6312         expression->funcname.kind = kind;
6313
6314         next_token();
6315
6316         return expression;
6317 }
6318
6319 static designator_t *parse_designator(void)
6320 {
6321         designator_t *const result = allocate_ast_zero(sizeof(result[0]));
6322         result->symbol = expect_identifier("while parsing member designator", &result->pos);
6323         if (!result->symbol)
6324                 return NULL;
6325
6326         designator_t *last_designator = result;
6327         while (true) {
6328                 if (accept('.')) {
6329                         designator_t *const designator = allocate_ast_zero(sizeof(result[0]));
6330                         designator->symbol = expect_identifier("while parsing member designator", &designator->pos);
6331                         if (!designator->symbol)
6332                                 return NULL;
6333
6334                         last_designator->next = designator;
6335                         last_designator       = designator;
6336                         continue;
6337                 }
6338                 if (accept('[')) {
6339                         add_anchor_token(']');
6340                         designator_t *designator = allocate_ast_zero(sizeof(result[0]));
6341                         designator->pos          = *HERE;
6342                         designator->array_index  = parse_expression();
6343                         rem_anchor_token(']');
6344                         expect(']');
6345                         if (designator->array_index == NULL) {
6346                                 return NULL;
6347                         }
6348
6349                         last_designator->next = designator;
6350                         last_designator       = designator;
6351                         continue;
6352                 }
6353                 break;
6354         }
6355
6356         return result;
6357 }
6358
6359 /**
6360  * Parse the __builtin_offsetof() expression.
6361  */
6362 static expression_t *parse_offsetof(void)
6363 {
6364         expression_t *expression = allocate_expression_zero(EXPR_OFFSETOF);
6365         expression->base.type    = type_size_t;
6366
6367         eat(T___builtin_offsetof);
6368
6369         add_anchor_token(')');
6370         add_anchor_token(',');
6371         expect('(');
6372         type_t *type = parse_typename();
6373         rem_anchor_token(',');
6374         expect(',');
6375         designator_t *designator = parse_designator();
6376         rem_anchor_token(')');
6377         expect(')');
6378
6379         expression->offsetofe.type       = type;
6380         expression->offsetofe.designator = designator;
6381
6382         type_path_t path;
6383         memset(&path, 0, sizeof(path));
6384         path.top_type = type;
6385         path.path     = NEW_ARR_F(type_path_entry_t, 0);
6386
6387         descend_into_subtype(&path);
6388
6389         if (!walk_designator(&path, designator, true)) {
6390                 return create_error_expression();
6391         }
6392
6393         DEL_ARR_F(path.path);
6394
6395         return expression;
6396 }
6397
6398 static bool is_last_parameter(expression_t *const param)
6399 {
6400         if (param->kind == EXPR_REFERENCE) {
6401                 entity_t *const entity = param->reference.entity;
6402                 if (entity->kind == ENTITY_PARAMETER &&
6403                     !entity->base.next               &&
6404                     entity->base.parent_scope == &current_function->parameters) {
6405                         return true;
6406                 }
6407         }
6408
6409         if (!is_type_valid(skip_typeref(param->base.type)))
6410                 return true;
6411
6412         return false;
6413 }
6414
6415 /**
6416  * Parses a __builtin_va_start() expression.
6417  */
6418 static expression_t *parse_va_start(void)
6419 {
6420         expression_t *expression = allocate_expression_zero(EXPR_VA_START);
6421
6422         eat(T___builtin_va_start);
6423
6424         add_anchor_token(')');
6425         add_anchor_token(',');
6426         expect('(');
6427         expression->va_starte.ap = parse_assignment_expression();
6428         rem_anchor_token(',');
6429         expect(',');
6430         expression_t *const param = parse_assignment_expression();
6431         expression->va_starte.parameter = param;
6432         rem_anchor_token(')');
6433         expect(')');
6434
6435         if (!current_function) {
6436                 errorf(&expression->base.pos, "'va_start' used outside of function");
6437         } else if (!current_function->base.type->function.variadic) {
6438                 errorf(&expression->base.pos, "'va_start' used in non-variadic function");
6439         } else if (!is_last_parameter(param)) {
6440                 errorf(&param->base.pos, "second argument of 'va_start' must be last parameter of the current function");
6441         }
6442
6443         return expression;
6444 }
6445
6446 /**
6447  * Parses a __builtin_va_arg() expression.
6448  */
6449 static expression_t *parse_va_arg(void)
6450 {
6451         expression_t *expression = allocate_expression_zero(EXPR_VA_ARG);
6452
6453         eat(T___builtin_va_arg);
6454
6455         add_anchor_token(')');
6456         add_anchor_token(',');
6457         expect('(');
6458         call_argument_t ap;
6459         ap.expression = parse_assignment_expression();
6460         expression->va_arge.ap = ap.expression;
6461         check_call_argument(type_valist, &ap, 1);
6462
6463         rem_anchor_token(',');
6464         expect(',');
6465         expression->base.type = parse_typename();
6466         rem_anchor_token(')');
6467         expect(')');
6468
6469         return expression;
6470 }
6471
6472 /**
6473  * Parses a __builtin_va_copy() expression.
6474  */
6475 static expression_t *parse_va_copy(void)
6476 {
6477         expression_t *expression = allocate_expression_zero(EXPR_VA_COPY);
6478
6479         eat(T___builtin_va_copy);
6480
6481         add_anchor_token(')');
6482         add_anchor_token(',');
6483         expect('(');
6484         expression_t *dst = parse_assignment_expression();
6485         assign_error_t error = semantic_assign(type_valist, dst);
6486         report_assign_error(error, type_valist, dst, "call argument 1",
6487                             &dst->base.pos);
6488         expression->va_copye.dst = dst;
6489
6490         rem_anchor_token(',');
6491         expect(',');
6492
6493         call_argument_t src;
6494         src.expression = parse_assignment_expression();
6495         check_call_argument(type_valist, &src, 2);
6496         expression->va_copye.src = src.expression;
6497         rem_anchor_token(')');
6498         expect(')');
6499
6500         return expression;
6501 }
6502
6503 /**
6504  * Parses a __builtin_constant_p() expression.
6505  */
6506 static expression_t *parse_builtin_constant(void)
6507 {
6508         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_CONSTANT_P);
6509
6510         eat(T___builtin_constant_p);
6511
6512         add_anchor_token(')');
6513         expect('(');
6514         expression->builtin_constant.value = parse_assignment_expression();
6515         rem_anchor_token(')');
6516         expect(')');
6517         expression->base.type = type_int;
6518
6519         return expression;
6520 }
6521
6522 /**
6523  * Parses a __builtin_types_compatible_p() expression.
6524  */
6525 static expression_t *parse_builtin_types_compatible(void)
6526 {
6527         expression_t *expression = allocate_expression_zero(EXPR_BUILTIN_TYPES_COMPATIBLE_P);
6528
6529         eat(T___builtin_types_compatible_p);
6530
6531         add_anchor_token(')');
6532         add_anchor_token(',');
6533         expect('(');
6534         expression->builtin_types_compatible.left = parse_typename();
6535         rem_anchor_token(',');
6536         expect(',');
6537         expression->builtin_types_compatible.right = parse_typename();
6538         rem_anchor_token(')');
6539         expect(')');
6540         expression->base.type = type_int;
6541
6542         return expression;
6543 }
6544
6545 /**
6546  * Parses a __builtin_is_*() compare expression.
6547  */
6548 static expression_t *parse_compare_builtin(void)
6549 {
6550         expression_kind_t kind;
6551         switch (token.kind) {
6552         case T___builtin_isgreater:      kind = EXPR_BINARY_ISGREATER;      break;
6553         case T___builtin_isgreaterequal: kind = EXPR_BINARY_ISGREATEREQUAL; break;
6554         case T___builtin_isless:         kind = EXPR_BINARY_ISLESS;         break;
6555         case T___builtin_islessequal:    kind = EXPR_BINARY_ISLESSEQUAL;    break;
6556         case T___builtin_islessgreater:  kind = EXPR_BINARY_ISLESSGREATER;  break;
6557         case T___builtin_isunordered:    kind = EXPR_BINARY_ISUNORDERED;    break;
6558         default: internal_errorf(HERE, "invalid compare builtin found");
6559         }
6560         expression_t *const expression = allocate_expression_zero(kind);
6561         next_token();
6562
6563         add_anchor_token(')');
6564         add_anchor_token(',');
6565         expect('(');
6566         expression->binary.left = parse_assignment_expression();
6567         rem_anchor_token(',');
6568         expect(',');
6569         expression->binary.right = parse_assignment_expression();
6570         rem_anchor_token(')');
6571         expect(')');
6572
6573         type_t *const orig_type_left  = expression->binary.left->base.type;
6574         type_t *const orig_type_right = expression->binary.right->base.type;
6575
6576         type_t *const type_left  = skip_typeref(orig_type_left);
6577         type_t *const type_right = skip_typeref(orig_type_right);
6578         if (!is_type_float(type_left) && !is_type_float(type_right)) {
6579                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
6580                         type_error_incompatible("invalid operands in comparison",
6581                                 &expression->base.pos, orig_type_left, orig_type_right);
6582                 }
6583         } else {
6584                 semantic_comparison(&expression->binary);
6585         }
6586
6587         return expression;
6588 }
6589
6590 /**
6591  * Parses a MS assume() expression.
6592  */
6593 static expression_t *parse_assume(void)
6594 {
6595         expression_t *expression = allocate_expression_zero(EXPR_UNARY_ASSUME);
6596
6597         eat(T__assume);
6598
6599         add_anchor_token(')');
6600         expect('(');
6601         expression->unary.value = parse_assignment_expression();
6602         rem_anchor_token(')');
6603         expect(')');
6604
6605         expression->base.type = type_void;
6606         return expression;
6607 }
6608
6609 /**
6610  * Return the label for the current symbol or create a new one.
6611  */
6612 static label_t *get_label(char const *const context)
6613 {
6614         assert(current_function != NULL);
6615
6616         symbol_t *const sym = expect_identifier(context, NULL);
6617         if (!sym)
6618                 return NULL;
6619
6620         entity_t *label = get_entity(sym, NAMESPACE_LABEL);
6621         /* If we find a local label, we already created the declaration. */
6622         if (label != NULL && label->kind == ENTITY_LOCAL_LABEL) {
6623                 if (label->base.parent_scope != current_scope) {
6624                         assert(label->base.parent_scope->depth < current_scope->depth);
6625                         current_function->goto_to_outer = true;
6626                 }
6627         } else if (label == NULL || label->base.parent_scope != &current_function->parameters) {
6628                 /* There is no matching label in the same function, so create a new one. */
6629                 position_t const nowhere = { NULL, 0, 0, false };
6630                 label = allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym, &nowhere);
6631                 label_push(label);
6632         }
6633
6634         return &label->label;
6635 }
6636
6637 /**
6638  * Parses a GNU && label address expression.
6639  */
6640 static expression_t *parse_label_address(void)
6641 {
6642         position_t const pos = *HERE;
6643         eat(T_ANDAND);
6644
6645         label_t *const label = get_label("while parsing label address");
6646         if (!label)
6647                 return create_error_expression();
6648
6649         label->used          = true;
6650         label->address_taken = true;
6651
6652         expression_t *expression = allocate_expression_zero(EXPR_LABEL_ADDRESS);
6653         expression->base.pos     = pos;
6654
6655         /* label address is treated as a void pointer */
6656         expression->base.type           = type_void_ptr;
6657         expression->label_address.label = label;
6658         return expression;
6659 }
6660
6661 /**
6662  * Parse a microsoft __noop expression.
6663  */
6664 static expression_t *parse_noop_expression(void)
6665 {
6666         /* the result is a (int)0 */
6667         expression_t *literal = allocate_expression_zero(EXPR_LITERAL_MS_NOOP);
6668         literal->base.type           = type_int;
6669         literal->literal.value.begin = "__noop";
6670         literal->literal.value.size  = 6;
6671
6672         eat(T___noop);
6673
6674         if (token.kind == '(') {
6675                 /* parse arguments */
6676                 eat('(');
6677                 add_anchor_token(')');
6678                 add_anchor_token(',');
6679
6680                 if (token.kind != ')') do {
6681                         (void)parse_assignment_expression();
6682                 } while (accept(','));
6683
6684                 rem_anchor_token(',');
6685                 rem_anchor_token(')');
6686         }
6687         expect(')');
6688
6689         return literal;
6690 }
6691
6692 /**
6693  * Parses a primary expression.
6694  */
6695 static expression_t *parse_primary_expression(void)
6696 {
6697         switch (token.kind) {
6698         case T_false:                        return parse_boolean_literal(false);
6699         case T_true:                         return parse_boolean_literal(true);
6700         case T_NUMBER:                       return parse_number_literal();
6701         case T_CHARACTER_CONSTANT:           return parse_character_constant();
6702         case T_STRING_LITERAL:               return parse_string_literal();
6703         case T___func__:                     return parse_function_keyword(FUNCNAME_FUNCTION);
6704         case T___PRETTY_FUNCTION__:          return parse_function_keyword(FUNCNAME_PRETTY_FUNCTION);
6705         case T___FUNCSIG__:                  return parse_function_keyword(FUNCNAME_FUNCSIG);
6706         case T___FUNCDNAME__:                return parse_function_keyword(FUNCNAME_FUNCDNAME);
6707         case T___builtin_offsetof:           return parse_offsetof();
6708         case T___builtin_va_start:           return parse_va_start();
6709         case T___builtin_va_arg:             return parse_va_arg();
6710         case T___builtin_va_copy:            return parse_va_copy();
6711         case T___builtin_isgreater:
6712         case T___builtin_isgreaterequal:
6713         case T___builtin_isless:
6714         case T___builtin_islessequal:
6715         case T___builtin_islessgreater:
6716         case T___builtin_isunordered:        return parse_compare_builtin();
6717         case T___builtin_constant_p:         return parse_builtin_constant();
6718         case T___builtin_types_compatible_p: return parse_builtin_types_compatible();
6719         case T__assume:                      return parse_assume();
6720         case T_ANDAND:
6721                 if (GNU_MODE)
6722                         return parse_label_address();
6723                 break;
6724
6725         case '(':                            return parse_parenthesized_expression();
6726         case T___noop:                       return parse_noop_expression();
6727
6728         /* Gracefully handle type names while parsing expressions. */
6729         case T_COLONCOLON:
6730                 return parse_reference();
6731         case T_IDENTIFIER:
6732                 if (!is_typedef_symbol(token.base.symbol)) {
6733                         return parse_reference();
6734                 }
6735                 /* FALLTHROUGH */
6736         DECLARATION_START {
6737                 position_t const pos = *HERE;
6738                 declaration_specifiers_t specifiers;
6739                 parse_declaration_specifiers(&specifiers);
6740                 type_t const *const type = parse_abstract_declarator(specifiers.type);
6741                 errorf(&pos, "encountered type '%T' while parsing expression", type);
6742                 return create_error_expression();
6743         }
6744         }
6745
6746         errorf(HERE, "unexpected token %K, expected an expression", &token);
6747         eat_until_anchor();
6748         return create_error_expression();
6749 }
6750
6751 static expression_t *parse_array_expression(expression_t *left)
6752 {
6753         expression_t              *const expr = allocate_expression_zero(EXPR_ARRAY_ACCESS);
6754         array_access_expression_t *const arr  = &expr->array_access;
6755
6756         eat('[');
6757         add_anchor_token(']');
6758
6759         expression_t *const inside = parse_expression();
6760
6761         type_t *const orig_type_left   = left->base.type;
6762         type_t *const orig_type_inside = inside->base.type;
6763
6764         type_t *const type_left   = skip_typeref(orig_type_left);
6765         type_t *const type_inside = skip_typeref(orig_type_inside);
6766
6767         expression_t *ref;
6768         expression_t *idx;
6769         type_t       *idx_type;
6770         type_t       *res_type;
6771         if (is_type_pointer(type_left)) {
6772                 ref      = left;
6773                 idx      = inside;
6774                 idx_type = type_inside;
6775                 res_type = type_left->pointer.points_to;
6776                 goto check_idx;
6777         } else if (is_type_pointer(type_inside)) {
6778                 arr->flipped = true;
6779                 ref      = inside;
6780                 idx      = left;
6781                 idx_type = type_left;
6782                 res_type = type_inside->pointer.points_to;
6783 check_idx:
6784                 res_type = automatic_type_conversion(res_type);
6785                 if (!is_type_integer(idx_type)) {
6786                         if (is_type_valid(idx_type))
6787                                 errorf(&idx->base.pos, "array subscript must have integer type");
6788                 } else if (is_type_atomic(idx_type, ATOMIC_TYPE_CHAR)) {
6789                         position_t const *const pos = &idx->base.pos;
6790                         warningf(WARN_CHAR_SUBSCRIPTS, pos, "array subscript has char type");
6791                 }
6792         } else {
6793                 if (is_type_valid(type_left) && is_type_valid(type_inside)) {
6794                         errorf(&expr->base.pos, "invalid types '%T[%T]' for array access", orig_type_left, orig_type_inside);
6795                 }
6796                 res_type = type_error_type;
6797                 ref      = left;
6798                 idx      = inside;
6799         }
6800
6801         arr->array_ref = ref;
6802         arr->index     = idx;
6803         arr->base.type = res_type;
6804
6805         rem_anchor_token(']');
6806         expect(']');
6807         return expr;
6808 }
6809
6810 static bool is_bitfield(const expression_t *expression)
6811 {
6812         return expression->kind == EXPR_SELECT
6813                 && expression->select.compound_entry->compound_member.bitfield;
6814 }
6815
6816 static expression_t *parse_typeprop(expression_kind_t const kind)
6817 {
6818         expression_t  *tp_expression = allocate_expression_zero(kind);
6819         tp_expression->base.type     = type_size_t;
6820
6821         eat(kind == EXPR_SIZEOF ? T_sizeof : T__Alignof);
6822
6823         type_t       *orig_type;
6824         expression_t *expression;
6825         if (token.kind == '(' && is_declaration_specifier(look_ahead(1))) {
6826                 position_t const pos = *HERE;
6827                 eat('(');
6828                 add_anchor_token(')');
6829                 orig_type = parse_typename();
6830                 rem_anchor_token(')');
6831                 expect(')');
6832
6833                 if (token.kind == '{') {
6834                         /* It was not sizeof(type) after all.  It is sizeof of an expression
6835                          * starting with a compound literal */
6836                         expression = parse_compound_literal(&pos, orig_type);
6837                         goto typeprop_expression;
6838                 }
6839         } else {
6840                 expression = parse_subexpression(PREC_UNARY);
6841
6842 typeprop_expression:
6843                 if (is_bitfield(expression)) {
6844                         char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6845                         errorf(&tp_expression->base.pos,
6846                                    "operand of %s expression must not be a bitfield", what);
6847                 }
6848
6849                 tp_expression->typeprop.tp_expression = expression;
6850
6851                 orig_type = revert_automatic_type_conversion(expression);
6852                 expression->base.type = orig_type;
6853         }
6854
6855         tp_expression->typeprop.type   = orig_type;
6856         type_t const* const type       = skip_typeref(orig_type);
6857         char   const*       wrong_type = NULL;
6858         if (is_type_incomplete(type)) {
6859                 if (!is_type_void(type) || !GNU_MODE)
6860                         wrong_type = "incomplete";
6861         } else if (type->kind == TYPE_FUNCTION) {
6862                 if (GNU_MODE) {
6863                         /* function types are allowed (and return 1) */
6864                         position_t const *const pos  = &tp_expression->base.pos;
6865                         char       const *const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6866                         warningf(WARN_OTHER, pos, "%s expression with function argument returns invalid result", what);
6867                 } else {
6868                         wrong_type = "function";
6869                 }
6870         }
6871
6872         if (wrong_type != NULL) {
6873                 char const* const what = kind == EXPR_SIZEOF ? "sizeof" : "alignof";
6874                 errorf(&tp_expression->base.pos,
6875                                 "operand of %s expression must not be of %s type '%T'",
6876                                 what, wrong_type, orig_type);
6877         }
6878
6879         return tp_expression;
6880 }
6881
6882 static expression_t *parse_sizeof(void)
6883 {
6884         return parse_typeprop(EXPR_SIZEOF);
6885 }
6886
6887 static expression_t *parse_alignof(void)
6888 {
6889         return parse_typeprop(EXPR_ALIGNOF);
6890 }
6891
6892 static expression_t *parse_select_expression(expression_t *addr)
6893 {
6894         assert(token.kind == '.' || token.kind == T_MINUSGREATER);
6895         bool select_left_arrow = (token.kind == T_MINUSGREATER);
6896         position_t const pos = *HERE;
6897         next_token();
6898
6899         symbol_t *const symbol = expect_identifier("while parsing select", NULL);
6900         if (!symbol)
6901                 return create_error_expression();
6902
6903         type_t *const orig_type = addr->base.type;
6904         type_t *const type      = skip_typeref(orig_type);
6905
6906         type_t *type_left;
6907         bool    saw_error = false;
6908         if (is_type_pointer(type)) {
6909                 if (!select_left_arrow) {
6910                         errorf(&pos,
6911                                "request for member '%Y' in something not a struct or union, but '%T'",
6912                                symbol, orig_type);
6913                         saw_error = true;
6914                 }
6915                 type_left = skip_typeref(type->pointer.points_to);
6916         } else {
6917                 if (select_left_arrow && is_type_valid(type)) {
6918                         errorf(&pos, "left hand side of '->' is not a pointer, but '%T'", orig_type);
6919                         saw_error = true;
6920                 }
6921                 type_left = type;
6922         }
6923
6924         if (!is_type_compound(type_left)) {
6925                 if (is_type_valid(type_left) && !saw_error) {
6926                         errorf(&pos,
6927                                "request for member '%Y' in something not a struct or union, but '%T'",
6928                                symbol, type_left);
6929                 }
6930                 return create_error_expression();
6931         }
6932
6933         compound_t *compound = type_left->compound.compound;
6934         if (!compound->complete) {
6935                 errorf(&pos, "request for member '%Y' in incomplete type '%T'",
6936                        symbol, type_left);
6937                 return create_error_expression();
6938         }
6939
6940         type_qualifiers_t  qualifiers = type_left->base.qualifiers;
6941         expression_t      *result     =
6942                 find_create_select(&pos, addr, qualifiers, compound, symbol);
6943
6944         if (result == NULL) {
6945                 errorf(&pos, "'%T' has no member named '%Y'", orig_type, symbol);
6946                 return create_error_expression();
6947         }
6948
6949         return result;
6950 }
6951
6952 static void check_call_argument(type_t          *expected_type,
6953                                 call_argument_t *argument, unsigned pos)
6954 {
6955         type_t         *expected_type_skip = skip_typeref(expected_type);
6956         assign_error_t  error              = ASSIGN_ERROR_INCOMPATIBLE;
6957         expression_t   *arg_expr           = argument->expression;
6958         type_t         *arg_type           = skip_typeref(arg_expr->base.type);
6959
6960         /* handle transparent union gnu extension */
6961         if (is_type_union(expected_type_skip)
6962                         && (get_type_modifiers(expected_type) & DM_TRANSPARENT_UNION)) {
6963                 compound_t *union_decl  = expected_type_skip->compound.compound;
6964                 type_t     *best_type   = NULL;
6965                 entity_t   *entry       = union_decl->members.entities;
6966                 for ( ; entry != NULL; entry = entry->base.next) {
6967                         assert(is_declaration(entry));
6968                         type_t *decl_type = entry->declaration.type;
6969                         error = semantic_assign(decl_type, arg_expr);
6970                         if (error == ASSIGN_ERROR_INCOMPATIBLE
6971                                 || error == ASSIGN_ERROR_POINTER_QUALIFIER_MISSING)
6972                                 continue;
6973
6974                         if (error == ASSIGN_SUCCESS) {
6975                                 best_type = decl_type;
6976                         } else if (best_type == NULL) {
6977                                 best_type = decl_type;
6978                         }
6979                 }
6980
6981                 if (best_type != NULL) {
6982                         expected_type = best_type;
6983                 }
6984         }
6985
6986         error                = semantic_assign(expected_type, arg_expr);
6987         argument->expression = create_implicit_cast(arg_expr, expected_type);
6988
6989         if (error != ASSIGN_SUCCESS) {
6990                 /* report exact scope in error messages (like "in argument 3") */
6991                 char buf[64];
6992                 snprintf(buf, sizeof(buf), "call argument %u", pos);
6993                 report_assign_error(error, expected_type, arg_expr, buf,
6994                                     &arg_expr->base.pos);
6995         } else {
6996                 type_t *const promoted_type = get_default_promoted_type(arg_type);
6997                 if (!types_compatible(expected_type_skip, promoted_type) &&
6998                     !types_compatible(expected_type_skip, type_void_ptr) &&
6999                     !types_compatible(type_void_ptr,      promoted_type)) {
7000                         /* Deliberately show the skipped types in this warning */
7001                         position_t const *const apos = &arg_expr->base.pos;
7002                         warningf(WARN_TRADITIONAL, apos, "passing call argument %u as '%T' rather than '%T' due to prototype", pos, expected_type_skip, promoted_type);
7003                 }
7004         }
7005 }
7006
7007 /**
7008  * Handle the semantic restrictions of builtin calls
7009  */
7010 static void handle_builtin_argument_restrictions(call_expression_t *call)
7011 {
7012         entity_t *entity = call->function->reference.entity;
7013         switch (entity->function.btk) {
7014         case BUILTIN_FIRM:
7015                 switch (entity->function.b.firm_builtin_kind) {
7016                 case ir_bk_return_address:
7017                 case ir_bk_frame_address: {
7018                         /* argument must be constant */
7019                         call_argument_t *argument = call->arguments;
7020
7021                         if (is_constant_expression(argument->expression) == EXPR_CLASS_VARIABLE) {
7022                                 errorf(&call->base.pos,
7023                                            "argument of '%Y' must be a constant expression",
7024                                            call->function->reference.entity->base.symbol);
7025                         }
7026                         break;
7027                 }
7028                 case ir_bk_prefetch:
7029                         /* second and third argument must be constant if existent */
7030                         if (call->arguments == NULL)
7031                                 break;
7032                         call_argument_t *rw = call->arguments->next;
7033                         call_argument_t *locality = NULL;
7034
7035                         if (rw != NULL) {
7036                                 if (is_constant_expression(rw->expression) == EXPR_CLASS_VARIABLE) {
7037                                         errorf(&call->base.pos,
7038                                                    "second argument of '%Y' must be a constant expression",
7039                                                    call->function->reference.entity->base.symbol);
7040                                 }
7041                                 locality = rw->next;
7042                         }
7043                         if (locality != NULL) {
7044                                 if (is_constant_expression(locality->expression) == EXPR_CLASS_VARIABLE) {
7045                                         errorf(&call->base.pos,
7046                                                    "third argument of '%Y' must be a constant expression",
7047                                                    call->function->reference.entity->base.symbol);
7048                                 }
7049                         }
7050                         break;
7051                 default:
7052                         break;
7053                 }
7054
7055         case BUILTIN_OBJECT_SIZE:
7056                 if (call->arguments == NULL)
7057                         break;
7058
7059                 call_argument_t *arg = call->arguments->next;
7060                 if (arg != NULL && is_constant_expression(arg->expression) == EXPR_CLASS_VARIABLE) {
7061                         errorf(&call->base.pos,
7062                                    "second argument of '%Y' must be a constant expression",
7063                                    call->function->reference.entity->base.symbol);
7064                 }
7065                 break;
7066         default:
7067                 break;
7068         }
7069 }
7070
7071 /**
7072  * Parse a call expression, i.e. expression '( ... )'.
7073  *
7074  * @param expression  the function address
7075  */
7076 static expression_t *parse_call_expression(expression_t *expression)
7077 {
7078         expression_t      *result = allocate_expression_zero(EXPR_CALL);
7079         call_expression_t *call   = &result->call;
7080         call->function            = expression;
7081
7082         type_t *const orig_type = expression->base.type;
7083         type_t *const type      = skip_typeref(orig_type);
7084
7085         function_type_t *function_type = NULL;
7086         if (is_type_pointer(type)) {
7087                 type_t *const to_type = skip_typeref(type->pointer.points_to);
7088
7089                 if (is_type_function(to_type)) {
7090                         function_type   = &to_type->function;
7091                         call->base.type = function_type->return_type;
7092                 }
7093         }
7094
7095         if (function_type == NULL && is_type_valid(type)) {
7096                 errorf(HERE,
7097                        "called object '%E' (type '%T') is not a pointer to a function",
7098                        expression, orig_type);
7099         }
7100
7101         /* parse arguments */
7102         eat('(');
7103         add_anchor_token(')');
7104         add_anchor_token(',');
7105
7106         if (token.kind != ')') {
7107                 call_argument_t **anchor = &call->arguments;
7108                 do {
7109                         call_argument_t *argument = allocate_ast_zero(sizeof(*argument));
7110                         argument->expression = parse_assignment_expression();
7111
7112                         *anchor = argument;
7113                         anchor  = &argument->next;
7114                 } while (accept(','));
7115         }
7116         rem_anchor_token(',');
7117         rem_anchor_token(')');
7118         expect(')');
7119
7120         if (function_type == NULL)
7121                 return result;
7122
7123         /* check type and count of call arguments */
7124         function_parameter_t *parameter = function_type->parameters;
7125         call_argument_t      *argument  = call->arguments;
7126         if (!function_type->unspecified_parameters) {
7127                 for (unsigned pos = 0; parameter != NULL && argument != NULL;
7128                                 parameter = parameter->next, argument = argument->next) {
7129                         check_call_argument(parameter->type, argument, ++pos);
7130                 }
7131
7132                 if (parameter != NULL) {
7133                         errorf(&expression->base.pos, "too few arguments to function '%E'",
7134                                expression);
7135                 } else if (argument != NULL && !function_type->variadic) {
7136                         errorf(&argument->expression->base.pos,
7137                                "too many arguments to function '%E'", expression);
7138                 }
7139         }
7140
7141         /* do default promotion for other arguments */
7142         for (; argument != NULL; argument = argument->next) {
7143                 type_t *argument_type = argument->expression->base.type;
7144                 if (!is_type_object(skip_typeref(argument_type))) {
7145                         errorf(&argument->expression->base.pos,
7146                                "call argument '%E' must not be void", argument->expression);
7147                 }
7148
7149                 argument_type = get_default_promoted_type(argument_type);
7150
7151                 argument->expression
7152                         = create_implicit_cast(argument->expression, argument_type);
7153         }
7154
7155         check_format(call);
7156
7157         if (is_type_compound(skip_typeref(function_type->return_type))) {
7158                 position_t const *const pos = &expression->base.pos;
7159                 warningf(WARN_AGGREGATE_RETURN, pos, "function call has aggregate value");
7160         }
7161
7162         if (expression->kind == EXPR_REFERENCE) {
7163                 reference_expression_t *reference = &expression->reference;
7164                 if (reference->entity->kind == ENTITY_FUNCTION &&
7165                     reference->entity->function.btk != BUILTIN_NONE)
7166                         handle_builtin_argument_restrictions(call);
7167         }
7168
7169         return result;
7170 }
7171
7172 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right);
7173
7174 static bool same_compound_type(const type_t *type1, const type_t *type2)
7175 {
7176         return
7177                 is_type_compound(type1) &&
7178                 type1->kind == type2->kind &&
7179                 type1->compound.compound == type2->compound.compound;
7180 }
7181
7182 static expression_t const *get_reference_address(expression_t const *expr)
7183 {
7184         bool regular_take_address = true;
7185         for (;;) {
7186                 if (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7187                         expr = expr->unary.value;
7188                 } else {
7189                         regular_take_address = false;
7190                 }
7191
7192                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7193                         break;
7194
7195                 expr = expr->unary.value;
7196         }
7197
7198         if (expr->kind != EXPR_REFERENCE)
7199                 return NULL;
7200
7201         /* special case for functions which are automatically converted to a
7202          * pointer to function without an extra TAKE_ADDRESS operation */
7203         if (!regular_take_address &&
7204                         expr->reference.entity->kind != ENTITY_FUNCTION) {
7205                 return NULL;
7206         }
7207
7208         return expr;
7209 }
7210
7211 static void warn_reference_address_as_bool(expression_t const* expr)
7212 {
7213         expr = get_reference_address(expr);
7214         if (expr != NULL) {
7215                 position_t const *const pos = &expr->base.pos;
7216                 entity_t   const *const ent = expr->reference.entity;
7217                 warningf(WARN_ADDRESS, pos, "the address of '%N' will always evaluate as 'true'", ent);
7218         }
7219 }
7220
7221 static void warn_assignment_in_condition(const expression_t *const expr)
7222 {
7223         if (expr->base.kind != EXPR_BINARY_ASSIGN)
7224                 return;
7225         if (expr->base.parenthesized)
7226                 return;
7227         position_t const *const pos = &expr->base.pos;
7228         warningf(WARN_PARENTHESES, pos, "suggest parentheses around assignment used as truth value");
7229 }
7230
7231 static void semantic_condition(expression_t const *const expr,
7232                                char const *const context)
7233 {
7234         type_t *const type = skip_typeref(expr->base.type);
7235         if (is_type_scalar(type)) {
7236                 warn_reference_address_as_bool(expr);
7237                 warn_assignment_in_condition(expr);
7238         } else if (is_type_valid(type)) {
7239                 errorf(&expr->base.pos, "%s must have scalar type", context);
7240         }
7241 }
7242
7243 /**
7244  * Parse a conditional expression, i.e. 'expression ? ... : ...'.
7245  *
7246  * @param expression  the conditional expression
7247  */
7248 static expression_t *parse_conditional_expression(expression_t *expression)
7249 {
7250         expression_t *result = allocate_expression_zero(EXPR_CONDITIONAL);
7251
7252         conditional_expression_t *conditional = &result->conditional;
7253         conditional->condition                = expression;
7254
7255         eat('?');
7256         add_anchor_token(':');
7257
7258         /* §6.5.15:2  The first operand shall have scalar type. */
7259         semantic_condition(expression, "condition of conditional operator");
7260
7261         expression_t *true_expression = expression;
7262         bool          gnu_cond = false;
7263         if (GNU_MODE && token.kind == ':') {
7264                 gnu_cond = true;
7265         } else {
7266                 true_expression = parse_expression();
7267         }
7268         rem_anchor_token(':');
7269         expect(':');
7270         expression_t *false_expression =
7271                 parse_subexpression(c_mode & _CXX ? PREC_ASSIGNMENT : PREC_CONDITIONAL);
7272
7273         type_t *const orig_true_type  = true_expression->base.type;
7274         type_t *const orig_false_type = false_expression->base.type;
7275         type_t *const true_type       = skip_typeref(orig_true_type);
7276         type_t *const false_type      = skip_typeref(orig_false_type);
7277
7278         /* 6.5.15.3 */
7279         position_t const *const pos = &conditional->base.pos;
7280         type_t                 *result_type;
7281         if (is_type_void(true_type) || is_type_void(false_type)) {
7282                 /* ISO/IEC 14882:1998(E) §5.16:2 */
7283                 if (true_expression->kind == EXPR_UNARY_THROW) {
7284                         result_type = false_type;
7285                 } else if (false_expression->kind == EXPR_UNARY_THROW) {
7286                         result_type = true_type;
7287                 } else {
7288                         if (!is_type_void(true_type) || !is_type_void(false_type)) {
7289                                 warningf(WARN_OTHER, pos, "ISO C forbids conditional expression with only one void side");
7290                         }
7291                         result_type = type_void;
7292                 }
7293         } else if (is_type_arithmetic(true_type)
7294                    && is_type_arithmetic(false_type)) {
7295                 result_type = semantic_arithmetic(true_type, false_type);
7296         } else if (same_compound_type(true_type, false_type)) {
7297                 /* just take 1 of the 2 types */
7298                 result_type = true_type;
7299         } else if (is_type_pointer(true_type) || is_type_pointer(false_type)) {
7300                 type_t *pointer_type;
7301                 type_t *other_type;
7302                 expression_t *other_expression;
7303                 if (is_type_pointer(true_type) &&
7304                                 (!is_type_pointer(false_type) || is_null_pointer_constant(false_expression))) {
7305                         pointer_type     = true_type;
7306                         other_type       = false_type;
7307                         other_expression = false_expression;
7308                 } else {
7309                         pointer_type     = false_type;
7310                         other_type       = true_type;
7311                         other_expression = true_expression;
7312                 }
7313
7314                 if (is_null_pointer_constant(other_expression)) {
7315                         result_type = pointer_type;
7316                 } else if (is_type_pointer(other_type)) {
7317                         type_t *to1 = skip_typeref(pointer_type->pointer.points_to);
7318                         type_t *to2 = skip_typeref(other_type->pointer.points_to);
7319
7320                         type_t *to;
7321                         if (is_type_void(to1) || is_type_void(to2)) {
7322                                 to = type_void;
7323                         } else if (types_compatible(get_unqualified_type(to1),
7324                                                     get_unqualified_type(to2))) {
7325                                 to = to1;
7326                         } else {
7327                                 warningf(WARN_OTHER, pos, "pointer types '%T' and '%T' in conditional expression are incompatible", true_type, false_type);
7328                                 to = type_void;
7329                         }
7330
7331                         type_t *const type =
7332                                 get_qualified_type(to, to1->base.qualifiers | to2->base.qualifiers);
7333                         result_type = make_pointer_type(type, TYPE_QUALIFIER_NONE);
7334                 } else if (is_type_integer(other_type)) {
7335                         warningf(WARN_OTHER, pos, "pointer/integer type mismatch in conditional expression ('%T' and '%T')", true_type, false_type);
7336                         result_type = pointer_type;
7337                 } else {
7338                         goto types_incompatible;
7339                 }
7340         } else {
7341 types_incompatible:
7342                 if (is_type_valid(true_type) && is_type_valid(false_type)) {
7343                         type_error_incompatible("while parsing conditional", pos, true_type, false_type);
7344                 }
7345                 result_type = type_error_type;
7346         }
7347
7348         conditional->true_expression
7349                 = gnu_cond ? NULL : create_implicit_cast(true_expression, result_type);
7350         conditional->false_expression
7351                 = create_implicit_cast(false_expression, result_type);
7352         conditional->base.type = result_type;
7353         return result;
7354 }
7355
7356 /**
7357  * Parse an extension expression.
7358  */
7359 static expression_t *parse_extension(void)
7360 {
7361         PUSH_EXTENSION();
7362         expression_t *expression = parse_subexpression(PREC_UNARY);
7363         POP_EXTENSION();
7364         return expression;
7365 }
7366
7367 /**
7368  * Parse a __builtin_classify_type() expression.
7369  */
7370 static expression_t *parse_builtin_classify_type(void)
7371 {
7372         expression_t *result = allocate_expression_zero(EXPR_CLASSIFY_TYPE);
7373         result->base.type    = type_int;
7374
7375         eat(T___builtin_classify_type);
7376
7377         add_anchor_token(')');
7378         expect('(');
7379         expression_t *expression = parse_expression();
7380         rem_anchor_token(')');
7381         expect(')');
7382         result->classify_type.type_expression = expression;
7383
7384         return result;
7385 }
7386
7387 /**
7388  * Parse a delete expression
7389  * ISO/IEC 14882:1998(E) §5.3.5
7390  */
7391 static expression_t *parse_delete(void)
7392 {
7393         expression_t *const result = allocate_expression_zero(EXPR_UNARY_DELETE);
7394         result->base.type          = type_void;
7395
7396         eat(T_delete);
7397
7398         if (accept('[')) {
7399                 result->kind = EXPR_UNARY_DELETE_ARRAY;
7400                 expect(']');
7401         }
7402
7403         expression_t *const value = parse_subexpression(PREC_CAST);
7404         result->unary.value = value;
7405
7406         type_t *const type = skip_typeref(value->base.type);
7407         if (!is_type_pointer(type)) {
7408                 if (is_type_valid(type)) {
7409                         errorf(&value->base.pos,
7410                                         "operand of delete must have pointer type");
7411                 }
7412         } else if (is_type_void(skip_typeref(type->pointer.points_to))) {
7413                 position_t const *const pos = &value->base.pos;
7414                 warningf(WARN_OTHER, pos, "deleting 'void*' is undefined");
7415         }
7416
7417         return result;
7418 }
7419
7420 /**
7421  * Parse a throw expression
7422  * ISO/IEC 14882:1998(E) §15:1
7423  */
7424 static expression_t *parse_throw(void)
7425 {
7426         expression_t *const result = allocate_expression_zero(EXPR_UNARY_THROW);
7427         result->base.type          = type_void;
7428
7429         eat(T_throw);
7430
7431         expression_t *value = NULL;
7432         switch (token.kind) {
7433                 EXPRESSION_START {
7434                         value = parse_assignment_expression();
7435                         /* ISO/IEC 14882:1998(E) §15.1:3 */
7436                         type_t *const orig_type = value->base.type;
7437                         type_t *const type      = skip_typeref(orig_type);
7438                         if (is_type_incomplete(type)) {
7439                                 errorf(&value->base.pos,
7440                                                 "cannot throw object of incomplete type '%T'", orig_type);
7441                         } else if (is_type_pointer(type)) {
7442                                 type_t *const points_to = skip_typeref(type->pointer.points_to);
7443                                 if (is_type_incomplete(points_to) && !is_type_void(points_to)) {
7444                                         errorf(&value->base.pos,
7445                                                         "cannot throw pointer to incomplete type '%T'", orig_type);
7446                                 }
7447                         }
7448                 }
7449
7450                 default:
7451                         break;
7452         }
7453         result->unary.value = value;
7454
7455         return result;
7456 }
7457
7458 static bool check_pointer_arithmetic(const position_t *pos,
7459                                      type_t *pointer_type,
7460                                      type_t *orig_pointer_type)
7461 {
7462         type_t *points_to = pointer_type->pointer.points_to;
7463         points_to = skip_typeref(points_to);
7464
7465         if (is_type_incomplete(points_to)) {
7466                 if (!GNU_MODE || !is_type_void(points_to)) {
7467                         errorf(pos,
7468                                "arithmetic with pointer to incomplete type '%T' not allowed",
7469                                orig_pointer_type);
7470                         return false;
7471                 } else {
7472                         warningf(WARN_POINTER_ARITH, pos, "pointer of type '%T' used in arithmetic", orig_pointer_type);
7473                 }
7474         } else if (is_type_function(points_to)) {
7475                 if (!GNU_MODE) {
7476                         errorf(pos,
7477                                "arithmetic with pointer to function type '%T' not allowed",
7478                                orig_pointer_type);
7479                         return false;
7480                 } else {
7481                         warningf(WARN_POINTER_ARITH, pos,
7482                                  "pointer to a function '%T' used in arithmetic",
7483                                  orig_pointer_type);
7484                 }
7485         }
7486         return true;
7487 }
7488
7489 static bool is_lvalue(const expression_t *expression)
7490 {
7491         /* TODO: doesn't seem to be consistent with §6.3.2.1:1 */
7492         switch (expression->kind) {
7493         case EXPR_ARRAY_ACCESS:
7494         case EXPR_COMPOUND_LITERAL:
7495         case EXPR_REFERENCE:
7496         case EXPR_SELECT:
7497         case EXPR_UNARY_DEREFERENCE:
7498                 return true;
7499
7500         default: {
7501                 type_t *type = skip_typeref(expression->base.type);
7502                 return
7503                         /* ISO/IEC 14882:1998(E) §3.10:3 */
7504                         is_type_reference(type) ||
7505                         /* Claim it is an lvalue, if the type is invalid.  There was a parse
7506                          * error before, which maybe prevented properly recognizing it as
7507                          * lvalue. */
7508                         !is_type_valid(type);
7509         }
7510         }
7511 }
7512
7513 static void semantic_incdec(unary_expression_t *expression)
7514 {
7515         type_t *const orig_type = expression->value->base.type;
7516         type_t *const type      = skip_typeref(orig_type);
7517         if (is_type_pointer(type)) {
7518                 if (!check_pointer_arithmetic(&expression->base.pos, type, orig_type)) {
7519                         return;
7520                 }
7521         } else if (!is_type_real(type) && is_type_valid(type)) {
7522                 /* TODO: improve error message */
7523                 errorf(&expression->base.pos,
7524                        "operation needs an arithmetic or pointer type");
7525                 return;
7526         }
7527         if (!is_lvalue(expression->value)) {
7528                 /* TODO: improve error message */
7529                 errorf(&expression->base.pos, "lvalue required as operand");
7530         }
7531         expression->base.type = orig_type;
7532 }
7533
7534 static void promote_unary_int_expr(unary_expression_t *const expr, type_t *const type)
7535 {
7536         type_t *const res_type = promote_integer(type);
7537         expr->base.type = res_type;
7538         expr->value     = create_implicit_cast(expr->value, res_type);
7539 }
7540
7541 static void semantic_unexpr_arithmetic(unary_expression_t *expression)
7542 {
7543         type_t *const orig_type = expression->value->base.type;
7544         type_t *const type      = skip_typeref(orig_type);
7545         if (!is_type_arithmetic(type)) {
7546                 if (is_type_valid(type)) {
7547                         position_t const *const pos = &expression->base.pos;
7548                         errorf(pos, "operand of unary expression must have arithmetic type, but is '%T'", orig_type);
7549                 }
7550                 return;
7551         } else if (is_type_integer(type)) {
7552                 promote_unary_int_expr(expression, type);
7553         } else {
7554                 expression->base.type = orig_type;
7555         }
7556 }
7557
7558 static void semantic_unexpr_plus(unary_expression_t *expression)
7559 {
7560         semantic_unexpr_arithmetic(expression);
7561         position_t const *const pos = &expression->base.pos;
7562         warningf(WARN_TRADITIONAL, pos, "traditional C rejects the unary plus operator");
7563 }
7564
7565 static void semantic_not(unary_expression_t *expression)
7566 {
7567         /* §6.5.3.3:1  The operand [...] of the ! operator, scalar type. */
7568         semantic_condition(expression->value, "operand of !");
7569         expression->base.type = c_mode & _CXX ? type_bool : type_int;
7570 }
7571
7572 static void semantic_unexpr_integer(unary_expression_t *expression)
7573 {
7574         type_t *const orig_type = expression->value->base.type;
7575         type_t *const type      = skip_typeref(orig_type);
7576         if (!is_type_integer(type)) {
7577                 if (is_type_valid(type)) {
7578                         errorf(&expression->base.pos, "operand of ~ must be of integer type");
7579                 }
7580                 return;
7581         }
7582
7583         promote_unary_int_expr(expression, type);
7584 }
7585
7586 static void semantic_dereference(unary_expression_t *expression)
7587 {
7588         type_t *const orig_type = expression->value->base.type;
7589         type_t *const type      = skip_typeref(orig_type);
7590         if (!is_type_pointer(type)) {
7591                 if (is_type_valid(type)) {
7592                         errorf(&expression->base.pos,
7593                                "Unary '*' needs pointer or array type, but type '%T' given", orig_type);
7594                 }
7595                 return;
7596         }
7597
7598         type_t *result_type   = type->pointer.points_to;
7599         result_type           = automatic_type_conversion(result_type);
7600         expression->base.type = result_type;
7601 }
7602
7603 /**
7604  * Record that an address is taken (expression represents an lvalue).
7605  *
7606  * @param expression       the expression
7607  * @param may_be_register  if true, the expression might be an register
7608  */
7609 static void set_address_taken(expression_t *expression, bool may_be_register)
7610 {
7611         if (expression->kind != EXPR_REFERENCE)
7612                 return;
7613
7614         entity_t *const entity = expression->reference.entity;
7615
7616         if (entity->kind != ENTITY_VARIABLE && entity->kind != ENTITY_PARAMETER)
7617                 return;
7618
7619         if (entity->declaration.storage_class == STORAGE_CLASS_REGISTER
7620                         && !may_be_register) {
7621                 position_t const *const pos = &expression->base.pos;
7622                 errorf(pos, "address of register '%N' requested", entity);
7623         }
7624
7625         entity->variable.address_taken = true;
7626 }
7627
7628 /**
7629  * Check the semantic of the address taken expression.
7630  */
7631 static void semantic_take_addr(unary_expression_t *expression)
7632 {
7633         expression_t *value = expression->value;
7634         value->base.type    = revert_automatic_type_conversion(value);
7635
7636         type_t *orig_type = value->base.type;
7637         type_t *type      = skip_typeref(orig_type);
7638         if (!is_type_valid(type))
7639                 return;
7640
7641         /* §6.5.3.2 */
7642         if (!is_lvalue(value)) {
7643                 errorf(&expression->base.pos, "'&' requires an lvalue");
7644         }
7645         if (is_bitfield(value)) {
7646                 errorf(&expression->base.pos, "'&' not allowed on bitfield");
7647         }
7648
7649         set_address_taken(value, false);
7650
7651         expression->base.type = make_pointer_type(orig_type, TYPE_QUALIFIER_NONE);
7652 }
7653
7654 #define CREATE_UNARY_EXPRESSION_PARSER(token_kind, unexpression_type, sfunc) \
7655 static expression_t *parse_##unexpression_type(void)                         \
7656 {                                                                            \
7657         expression_t *unary_expression                                           \
7658                 = allocate_expression_zero(unexpression_type);                       \
7659         eat(token_kind);                                                         \
7660         unary_expression->unary.value = parse_subexpression(PREC_UNARY);         \
7661                                                                                  \
7662         sfunc(&unary_expression->unary);                                         \
7663                                                                                  \
7664         return unary_expression;                                                 \
7665 }
7666
7667 CREATE_UNARY_EXPRESSION_PARSER('-', EXPR_UNARY_NEGATE,
7668                                semantic_unexpr_arithmetic)
7669 CREATE_UNARY_EXPRESSION_PARSER('+', EXPR_UNARY_PLUS,
7670                                semantic_unexpr_plus)
7671 CREATE_UNARY_EXPRESSION_PARSER('!', EXPR_UNARY_NOT,
7672                                semantic_not)
7673 CREATE_UNARY_EXPRESSION_PARSER('*', EXPR_UNARY_DEREFERENCE,
7674                                semantic_dereference)
7675 CREATE_UNARY_EXPRESSION_PARSER('&', EXPR_UNARY_TAKE_ADDRESS,
7676                                semantic_take_addr)
7677 CREATE_UNARY_EXPRESSION_PARSER('~', EXPR_UNARY_BITWISE_NEGATE,
7678                                semantic_unexpr_integer)
7679 CREATE_UNARY_EXPRESSION_PARSER(T_PLUSPLUS,   EXPR_UNARY_PREFIX_INCREMENT,
7680                                semantic_incdec)
7681 CREATE_UNARY_EXPRESSION_PARSER(T_MINUSMINUS, EXPR_UNARY_PREFIX_DECREMENT,
7682                                semantic_incdec)
7683
7684 #define CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(token_kind, unexpression_type, \
7685                                                sfunc)                         \
7686 static expression_t *parse_##unexpression_type(expression_t *left)            \
7687 {                                                                             \
7688         expression_t *unary_expression                                            \
7689                 = allocate_expression_zero(unexpression_type);                        \
7690         eat(token_kind);                                                          \
7691         unary_expression->unary.value = left;                                     \
7692                                                                                   \
7693         sfunc(&unary_expression->unary);                                          \
7694                                                                               \
7695         return unary_expression;                                                  \
7696 }
7697
7698 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_PLUSPLUS,
7699                                        EXPR_UNARY_POSTFIX_INCREMENT,
7700                                        semantic_incdec)
7701 CREATE_UNARY_POSTFIX_EXPRESSION_PARSER(T_MINUSMINUS,
7702                                        EXPR_UNARY_POSTFIX_DECREMENT,
7703                                        semantic_incdec)
7704
7705 static type_t *semantic_arithmetic(type_t *type_left, type_t *type_right)
7706 {
7707         /* TODO: handle complex + imaginary types */
7708
7709         type_left  = get_unqualified_type(type_left);
7710         type_right = get_unqualified_type(type_right);
7711
7712         /* §6.3.1.8 Usual arithmetic conversions */
7713         if (type_left == type_long_double || type_right == type_long_double) {
7714                 return type_long_double;
7715         } else if (type_left == type_double || type_right == type_double) {
7716                 return type_double;
7717         } else if (type_left == type_float || type_right == type_float) {
7718                 return type_float;
7719         }
7720
7721         type_left  = promote_integer(type_left);
7722         type_right = promote_integer(type_right);
7723
7724         if (type_left == type_right)
7725                 return type_left;
7726
7727         bool     const signed_left  = is_type_signed(type_left);
7728         bool     const signed_right = is_type_signed(type_right);
7729         unsigned const rank_left    = get_akind_rank(get_akind(type_left));
7730         unsigned const rank_right   = get_akind_rank(get_akind(type_right));
7731
7732         if (signed_left == signed_right)
7733                 return rank_left >= rank_right ? type_left : type_right;
7734
7735         unsigned           s_rank;
7736         unsigned           u_rank;
7737         atomic_type_kind_t s_akind;
7738         atomic_type_kind_t u_akind;
7739         type_t *s_type;
7740         type_t *u_type;
7741         if (signed_left) {
7742                 s_type = type_left;
7743                 u_type = type_right;
7744         } else {
7745                 s_type = type_right;
7746                 u_type = type_left;
7747         }
7748         s_akind = get_akind(s_type);
7749         u_akind = get_akind(u_type);
7750         s_rank  = get_akind_rank(s_akind);
7751         u_rank  = get_akind_rank(u_akind);
7752
7753         if (u_rank >= s_rank)
7754                 return u_type;
7755
7756         if (get_atomic_type_size(s_akind) > get_atomic_type_size(u_akind))
7757                 return s_type;
7758
7759         switch (s_akind) {
7760         case ATOMIC_TYPE_INT:      return type_unsigned_int;
7761         case ATOMIC_TYPE_LONG:     return type_unsigned_long;
7762         case ATOMIC_TYPE_LONGLONG: return type_unsigned_long_long;
7763
7764         default: panic("invalid atomic type");
7765         }
7766 }
7767
7768 /**
7769  * Check the semantic restrictions for a binary expression.
7770  */
7771 static void semantic_binexpr_arithmetic(binary_expression_t *expression)
7772 {
7773         expression_t *const left            = expression->left;
7774         expression_t *const right           = expression->right;
7775         type_t       *const orig_type_left  = left->base.type;
7776         type_t       *const orig_type_right = right->base.type;
7777         type_t       *const type_left       = skip_typeref(orig_type_left);
7778         type_t       *const type_right      = skip_typeref(orig_type_right);
7779
7780         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
7781                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7782                         position_t const *const pos = &expression->base.pos;
7783                         errorf(pos, "operands of binary expression must have arithmetic types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7784                 }
7785                 return;
7786         }
7787
7788         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7789         expression->left      = create_implicit_cast(left, arithmetic_type);
7790         expression->right     = create_implicit_cast(right, arithmetic_type);
7791         expression->base.type = arithmetic_type;
7792 }
7793
7794 static void semantic_binexpr_integer(binary_expression_t *const expression)
7795 {
7796         expression_t *const left            = expression->left;
7797         expression_t *const right           = expression->right;
7798         type_t       *const orig_type_left  = left->base.type;
7799         type_t       *const orig_type_right = right->base.type;
7800         type_t       *const type_left       = skip_typeref(orig_type_left);
7801         type_t       *const type_right      = skip_typeref(orig_type_right);
7802
7803         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7804                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7805                         position_t const *const pos = &expression->base.pos;
7806                         errorf(pos, "operands of binary expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7807                 }
7808                 return;
7809         }
7810
7811         type_t *const result_type = semantic_arithmetic(type_left, type_right);
7812         expression->left      = create_implicit_cast(left, result_type);
7813         expression->right     = create_implicit_cast(right, result_type);
7814         expression->base.type = result_type;
7815 }
7816
7817 static void warn_div_by_zero(binary_expression_t const *const expression)
7818 {
7819         if (!is_type_integer(expression->base.type))
7820                 return;
7821
7822         expression_t const *const right = expression->right;
7823         /* The type of the right operand can be different for /= */
7824         if (is_type_integer(right->base.type)                    &&
7825             is_constant_expression(right) == EXPR_CLASS_CONSTANT &&
7826             !fold_constant_to_bool(right)) {
7827                 position_t const *const pos = &expression->base.pos;
7828                 warningf(WARN_DIV_BY_ZERO, pos, "division by zero");
7829         }
7830 }
7831
7832 /**
7833  * Check the semantic restrictions for a div expression.
7834  */
7835 static void semantic_div(binary_expression_t *expression)
7836 {
7837         semantic_binexpr_arithmetic(expression);
7838         warn_div_by_zero(expression);
7839 }
7840
7841 /**
7842  * Check the semantic restrictions for a mod expression.
7843  */
7844 static void semantic_mod(binary_expression_t *expression)
7845 {
7846         semantic_binexpr_integer(expression);
7847         warn_div_by_zero(expression);
7848 }
7849
7850 static void warn_addsub_in_shift(const expression_t *const expr)
7851 {
7852         if (expr->base.parenthesized)
7853                 return;
7854
7855         char op;
7856         switch (expr->kind) {
7857                 case EXPR_BINARY_ADD: op = '+'; break;
7858                 case EXPR_BINARY_SUB: op = '-'; break;
7859                 default:              return;
7860         }
7861
7862         position_t const *const pos = &expr->base.pos;
7863         warningf(WARN_PARENTHESES, pos, "suggest parentheses around '%c' inside shift", op);
7864 }
7865
7866 static bool semantic_shift(binary_expression_t *expression)
7867 {
7868         expression_t *const left            = expression->left;
7869         expression_t *const right           = expression->right;
7870         type_t       *const orig_type_left  = left->base.type;
7871         type_t       *const orig_type_right = right->base.type;
7872         type_t       *      type_left       = skip_typeref(orig_type_left);
7873         type_t       *      type_right      = skip_typeref(orig_type_right);
7874
7875         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
7876                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
7877                         position_t const *const pos = &expression->base.pos;
7878                         errorf(pos, "operands of shift expression must have integer types, but are '%T' and '%T'", orig_type_left, orig_type_right);
7879                 }
7880                 return false;
7881         }
7882
7883         type_left = promote_integer(type_left);
7884
7885         if (is_constant_expression(right) == EXPR_CLASS_CONSTANT) {
7886                 position_t const *const pos   = &right->base.pos;
7887                 long              const count = fold_constant_to_int(right);
7888                 if (count < 0) {
7889                         warningf(WARN_OTHER, pos, "shift count must be non-negative");
7890                 } else if ((unsigned long)count >=
7891                                 get_atomic_type_size(type_left->atomic.akind) * 8) {
7892                         warningf(WARN_OTHER, pos, "shift count must be less than type width");
7893                 }
7894         }
7895
7896         type_right        = promote_integer(type_right);
7897         expression->right = create_implicit_cast(right, type_right);
7898
7899         return true;
7900 }
7901
7902 static void semantic_shift_op(binary_expression_t *expression)
7903 {
7904         expression_t *const left  = expression->left;
7905         expression_t *const right = expression->right;
7906
7907         if (!semantic_shift(expression))
7908                 return;
7909
7910         warn_addsub_in_shift(left);
7911         warn_addsub_in_shift(right);
7912
7913         type_t *const orig_type_left = left->base.type;
7914         type_t *      type_left      = skip_typeref(orig_type_left);
7915
7916         type_left             = promote_integer(type_left);
7917         expression->left      = create_implicit_cast(left, type_left);
7918         expression->base.type = type_left;
7919 }
7920
7921 static void semantic_add(binary_expression_t *expression)
7922 {
7923         expression_t *const left            = expression->left;
7924         expression_t *const right           = expression->right;
7925         type_t       *const orig_type_left  = left->base.type;
7926         type_t       *const orig_type_right = right->base.type;
7927         type_t       *const type_left       = skip_typeref(orig_type_left);
7928         type_t       *const type_right      = skip_typeref(orig_type_right);
7929
7930         /* §6.5.6 */
7931         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7932                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7933                 expression->left  = create_implicit_cast(left, arithmetic_type);
7934                 expression->right = create_implicit_cast(right, arithmetic_type);
7935                 expression->base.type = arithmetic_type;
7936         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7937                 check_pointer_arithmetic(&expression->base.pos, type_left,
7938                                          orig_type_left);
7939                 expression->base.type = type_left;
7940         } else if (is_type_pointer(type_right) && is_type_integer(type_left)) {
7941                 check_pointer_arithmetic(&expression->base.pos, type_right,
7942                                          orig_type_right);
7943                 expression->base.type = type_right;
7944         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7945                 errorf(&expression->base.pos,
7946                        "invalid operands to binary + ('%T', '%T')",
7947                        orig_type_left, orig_type_right);
7948         }
7949 }
7950
7951 static void semantic_sub(binary_expression_t *expression)
7952 {
7953         expression_t     *const left            = expression->left;
7954         expression_t     *const right           = expression->right;
7955         type_t           *const orig_type_left  = left->base.type;
7956         type_t           *const orig_type_right = right->base.type;
7957         type_t           *const type_left       = skip_typeref(orig_type_left);
7958         type_t           *const type_right      = skip_typeref(orig_type_right);
7959         position_t const *const pos             = &expression->base.pos;
7960
7961         /* §5.6.5 */
7962         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
7963                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
7964                 expression->left        = create_implicit_cast(left, arithmetic_type);
7965                 expression->right       = create_implicit_cast(right, arithmetic_type);
7966                 expression->base.type =  arithmetic_type;
7967         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
7968                 check_pointer_arithmetic(&expression->base.pos, type_left,
7969                                          orig_type_left);
7970                 expression->base.type = type_left;
7971         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
7972                 type_t *const unqual_left  = get_unqualified_type(skip_typeref(type_left->pointer.points_to));
7973                 type_t *const unqual_right = get_unqualified_type(skip_typeref(type_right->pointer.points_to));
7974                 if (!types_compatible(unqual_left, unqual_right)) {
7975                         errorf(pos,
7976                                "subtracting pointers to incompatible types '%T' and '%T'",
7977                                orig_type_left, orig_type_right);
7978                 } else if (!is_type_object(unqual_left)) {
7979                         if (!is_type_void(unqual_left)) {
7980                                 errorf(pos, "subtracting pointers to non-object types '%T'",
7981                                        orig_type_left);
7982                         } else {
7983                                 warningf(WARN_OTHER, pos, "subtracting pointers to void");
7984                         }
7985                 }
7986                 expression->base.type = type_ptrdiff_t;
7987         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
7988                 errorf(pos, "invalid operands of types '%T' and '%T' to binary '-'",
7989                        orig_type_left, orig_type_right);
7990         }
7991 }
7992
7993 static void warn_string_literal_address(expression_t const* expr)
7994 {
7995         while (expr->kind == EXPR_UNARY_TAKE_ADDRESS) {
7996                 expr = expr->unary.value;
7997                 if (expr->kind != EXPR_UNARY_DEREFERENCE)
7998                         return;
7999                 expr = expr->unary.value;
8000         }
8001
8002         if (expr->kind == EXPR_STRING_LITERAL) {
8003                 position_t const *const pos = &expr->base.pos;
8004                 warningf(WARN_ADDRESS, pos, "comparison with string literal results in unspecified behaviour");
8005         }
8006 }
8007
8008 static bool maybe_negative(expression_t const *const expr)
8009 {
8010         switch (is_constant_expression(expr)) {
8011                 case EXPR_CLASS_ERROR:    return false;
8012                 case EXPR_CLASS_CONSTANT: return constant_is_negative(expr);
8013                 default:                  return true;
8014         }
8015 }
8016
8017 static void warn_comparison(position_t const *const pos, expression_t const *const expr, expression_t const *const other)
8018 {
8019         warn_string_literal_address(expr);
8020
8021         expression_t const* const ref = get_reference_address(expr);
8022         if (ref != NULL && is_null_pointer_constant(other)) {
8023                 entity_t const *const ent = ref->reference.entity;
8024                 warningf(WARN_ADDRESS, pos, "the address of '%N' will never be NULL", ent);
8025         }
8026
8027         if (!expr->base.parenthesized) {
8028                 switch (expr->base.kind) {
8029                         case EXPR_BINARY_LESS:
8030                         case EXPR_BINARY_GREATER:
8031                         case EXPR_BINARY_LESSEQUAL:
8032                         case EXPR_BINARY_GREATEREQUAL:
8033                         case EXPR_BINARY_NOTEQUAL:
8034                         case EXPR_BINARY_EQUAL:
8035                                 warningf(WARN_PARENTHESES, pos, "comparisons like 'x <= y < z' do not have their mathematical meaning");
8036                                 break;
8037                         default:
8038                                 break;
8039                 }
8040         }
8041 }
8042
8043 /**
8044  * Check the semantics of comparison expressions.
8045  *
8046  * @param expression   The expression to check.
8047  */
8048 static void semantic_comparison(binary_expression_t *expression)
8049 {
8050         position_t const *const pos   = &expression->base.pos;
8051         expression_t     *const left  = expression->left;
8052         expression_t     *const right = expression->right;
8053
8054         warn_comparison(pos, left, right);
8055         warn_comparison(pos, right, left);
8056
8057         type_t *orig_type_left  = left->base.type;
8058         type_t *orig_type_right = right->base.type;
8059         type_t *type_left       = skip_typeref(orig_type_left);
8060         type_t *type_right      = skip_typeref(orig_type_right);
8061
8062         /* TODO non-arithmetic types */
8063         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8064                 type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8065
8066                 /* test for signed vs unsigned compares */
8067                 if (is_type_integer(arithmetic_type)) {
8068                         bool const signed_left  = is_type_signed(type_left);
8069                         bool const signed_right = is_type_signed(type_right);
8070                         if (signed_left != signed_right) {
8071                                 /* FIXME long long needs better const folding magic */
8072                                 /* TODO check whether constant value can be represented by other type */
8073                                 if ((signed_left  && maybe_negative(left)) ||
8074                                                 (signed_right && maybe_negative(right))) {
8075                                         warningf(WARN_SIGN_COMPARE, pos, "comparison between signed and unsigned");
8076                                 }
8077                         }
8078                 }
8079
8080                 expression->left        = create_implicit_cast(left, arithmetic_type);
8081                 expression->right       = create_implicit_cast(right, arithmetic_type);
8082                 expression->base.type   = arithmetic_type;
8083                 if ((expression->base.kind == EXPR_BINARY_EQUAL ||
8084                      expression->base.kind == EXPR_BINARY_NOTEQUAL) &&
8085                     is_type_float(arithmetic_type)) {
8086                         warningf(WARN_FLOAT_EQUAL, pos, "comparing floating point with == or != is unsafe");
8087                 }
8088         } else if (is_type_pointer(type_left) && is_type_pointer(type_right)) {
8089                 /* TODO check compatibility */
8090         } else if (is_type_pointer(type_left)) {
8091                 expression->right = create_implicit_cast(right, type_left);
8092         } else if (is_type_pointer(type_right)) {
8093                 expression->left = create_implicit_cast(left, type_right);
8094         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8095                 type_error_incompatible("invalid operands in comparison", pos, type_left, type_right);
8096         }
8097         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8098 }
8099
8100 /**
8101  * Checks if a compound type has constant fields.
8102  */
8103 static bool has_const_fields(const compound_type_t *type)
8104 {
8105         compound_t *compound = type->compound;
8106         entity_t   *entry    = compound->members.entities;
8107
8108         for (; entry != NULL; entry = entry->base.next) {
8109                 if (!is_declaration(entry))
8110                         continue;
8111
8112                 const type_t *decl_type = skip_typeref(entry->declaration.type);
8113                 if (decl_type->base.qualifiers & TYPE_QUALIFIER_CONST)
8114                         return true;
8115         }
8116
8117         return false;
8118 }
8119
8120 static bool is_valid_assignment_lhs(expression_t const* const left)
8121 {
8122         type_t *const orig_type_left = revert_automatic_type_conversion(left);
8123         type_t *const type_left      = skip_typeref(orig_type_left);
8124
8125         if (!is_lvalue(left)) {
8126                 errorf(&left->base.pos,
8127                        "left hand side '%E' of assignment is not an lvalue", left);
8128                 return false;
8129         }
8130
8131         if (left->kind == EXPR_REFERENCE
8132                         && left->reference.entity->kind == ENTITY_FUNCTION) {
8133                 errorf(&left->base.pos, "cannot assign to function '%E'", left);
8134                 return false;
8135         }
8136
8137         if (is_type_array(type_left)) {
8138                 errorf(&left->base.pos, "cannot assign to array '%E'", left);
8139                 return false;
8140         }
8141         if (type_left->base.qualifiers & TYPE_QUALIFIER_CONST) {
8142                 errorf(&left->base.pos,
8143                        "assignment to read-only location '%E' (type '%T')", left,
8144                        orig_type_left);
8145                 return false;
8146         }
8147         if (is_type_incomplete(type_left)) {
8148                 errorf(&left->base.pos, "left-hand side '%E' of assignment has incomplete type '%T'",
8149                        left, orig_type_left);
8150                 return false;
8151         }
8152         if (is_type_compound(type_left) && has_const_fields(&type_left->compound)) {
8153                 errorf(&left->base.pos, "cannot assign to '%E' because compound type '%T' has read-only fields",
8154                        left, orig_type_left);
8155                 return false;
8156         }
8157
8158         return true;
8159 }
8160
8161 static void semantic_arithmetic_assign(binary_expression_t *expression)
8162 {
8163         expression_t *left            = expression->left;
8164         expression_t *right           = expression->right;
8165         type_t       *orig_type_left  = left->base.type;
8166         type_t       *orig_type_right = right->base.type;
8167
8168         if (!is_valid_assignment_lhs(left))
8169                 return;
8170
8171         type_t *type_left  = skip_typeref(orig_type_left);
8172         type_t *type_right = skip_typeref(orig_type_right);
8173
8174         if (!is_type_arithmetic(type_left) || !is_type_arithmetic(type_right)) {
8175                 /* TODO: improve error message */
8176                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8177                         errorf(&expression->base.pos, "operation needs arithmetic types");
8178                 }
8179                 return;
8180         }
8181
8182         /* combined instructions are tricky. We can't create an implicit cast on
8183          * the left side, because we need the uncasted form for the store.
8184          * The ast2firm pass has to know that left_type must be right_type
8185          * for the arithmetic operation and create a cast by itself */
8186         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8187         expression->right       = create_implicit_cast(right, arithmetic_type);
8188         expression->base.type   = type_left;
8189 }
8190
8191 static void semantic_divmod_assign(binary_expression_t *expression)
8192 {
8193         semantic_arithmetic_assign(expression);
8194         warn_div_by_zero(expression);
8195 }
8196
8197 static void semantic_arithmetic_addsubb_assign(binary_expression_t *expression)
8198 {
8199         expression_t *const left            = expression->left;
8200         expression_t *const right           = expression->right;
8201         type_t       *const orig_type_left  = left->base.type;
8202         type_t       *const orig_type_right = right->base.type;
8203         type_t       *const type_left       = skip_typeref(orig_type_left);
8204         type_t       *const type_right      = skip_typeref(orig_type_right);
8205
8206         if (!is_valid_assignment_lhs(left))
8207                 return;
8208
8209         if (is_type_arithmetic(type_left) && is_type_arithmetic(type_right)) {
8210                 /* combined instructions are tricky. We can't create an implicit cast on
8211                  * the left side, because we need the uncasted form for the store.
8212                  * The ast2firm pass has to know that left_type must be right_type
8213                  * for the arithmetic operation and create a cast by itself */
8214                 type_t *const arithmetic_type = semantic_arithmetic(type_left, type_right);
8215                 expression->right     = create_implicit_cast(right, arithmetic_type);
8216                 expression->base.type = type_left;
8217         } else if (is_type_pointer(type_left) && is_type_integer(type_right)) {
8218                 check_pointer_arithmetic(&expression->base.pos, type_left,
8219                                          orig_type_left);
8220                 expression->base.type = type_left;
8221         } else if (is_type_valid(type_left) && is_type_valid(type_right)) {
8222                 errorf(&expression->base.pos,
8223                        "incompatible types '%T' and '%T' in assignment",
8224                        orig_type_left, orig_type_right);
8225         }
8226 }
8227
8228 static void semantic_integer_assign(binary_expression_t *expression)
8229 {
8230         expression_t *left            = expression->left;
8231         expression_t *right           = expression->right;
8232         type_t       *orig_type_left  = left->base.type;
8233         type_t       *orig_type_right = right->base.type;
8234
8235         if (!is_valid_assignment_lhs(left))
8236                 return;
8237
8238         type_t *type_left  = skip_typeref(orig_type_left);
8239         type_t *type_right = skip_typeref(orig_type_right);
8240
8241         if (!is_type_integer(type_left) || !is_type_integer(type_right)) {
8242                 /* TODO: improve error message */
8243                 if (is_type_valid(type_left) && is_type_valid(type_right)) {
8244                         errorf(&expression->base.pos, "operation needs integer types");
8245                 }
8246                 return;
8247         }
8248
8249         /* combined instructions are tricky. We can't create an implicit cast on
8250          * the left side, because we need the uncasted form for the store.
8251          * The ast2firm pass has to know that left_type must be right_type
8252          * for the arithmetic operation and create a cast by itself */
8253         type_t *arithmetic_type = semantic_arithmetic(type_left, type_right);
8254         expression->right       = create_implicit_cast(right, arithmetic_type);
8255         expression->base.type   = type_left;
8256 }
8257
8258 static void semantic_shift_assign(binary_expression_t *expression)
8259 {
8260         expression_t *left           = expression->left;
8261
8262         if (!is_valid_assignment_lhs(left))
8263                 return;
8264
8265         if (!semantic_shift(expression))
8266                 return;
8267
8268         expression->base.type = skip_typeref(left->base.type);
8269 }
8270
8271 static void warn_logical_and_within_or(const expression_t *const expr)
8272 {
8273         if (expr->base.kind != EXPR_BINARY_LOGICAL_AND)
8274                 return;
8275         if (expr->base.parenthesized)
8276                 return;
8277         position_t const *const pos = &expr->base.pos;
8278         warningf(WARN_PARENTHESES, pos, "suggest parentheses around && within ||");
8279 }
8280
8281 /**
8282  * Check the semantic restrictions of a logical expression.
8283  */
8284 static void semantic_logical_op(binary_expression_t *expression)
8285 {
8286         /* §6.5.13:2  Each of the operands shall have scalar type.
8287          * §6.5.14:2  Each of the operands shall have scalar type. */
8288         semantic_condition(expression->left,   "left operand of logical operator");
8289         semantic_condition(expression->right, "right operand of logical operator");
8290         if (expression->base.kind == EXPR_BINARY_LOGICAL_OR) {
8291                 warn_logical_and_within_or(expression->left);
8292                 warn_logical_and_within_or(expression->right);
8293         }
8294         expression->base.type = c_mode & _CXX ? type_bool : type_int;
8295 }
8296
8297 /**
8298  * Check the semantic restrictions of a binary assign expression.
8299  */
8300 static void semantic_binexpr_assign(binary_expression_t *expression)
8301 {
8302         expression_t *left           = expression->left;
8303         type_t       *orig_type_left = left->base.type;
8304
8305         if (!is_valid_assignment_lhs(left))
8306                 return;
8307
8308         assign_error_t error = semantic_assign(orig_type_left, expression->right);
8309         report_assign_error(error, orig_type_left, expression->right,
8310                             "assignment", &left->base.pos);
8311         expression->right = create_implicit_cast(expression->right, orig_type_left);
8312         expression->base.type = orig_type_left;
8313 }
8314
8315 /**
8316  * Determine if the outermost operation (or parts thereof) of the given
8317  * expression has no effect in order to generate a warning about this fact.
8318  * Therefore in some cases this only examines some of the operands of the
8319  * expression (see comments in the function and examples below).
8320  * Examples:
8321  *   f() + 23;    // warning, because + has no effect
8322  *   x || f();    // no warning, because x controls execution of f()
8323  *   x ? y : f(); // warning, because y has no effect
8324  *   (void)x;     // no warning to be able to suppress the warning
8325  * This function can NOT be used for an "expression has definitely no effect"-
8326  * analysis. */
8327 static bool expression_has_effect(const expression_t *const expr)
8328 {
8329         switch (expr->kind) {
8330                 case EXPR_ERROR:                      return true; /* do NOT warn */
8331                 case EXPR_REFERENCE:                  return false;
8332                 case EXPR_ENUM_CONSTANT:              return false;
8333                 case EXPR_LABEL_ADDRESS:              return false;
8334
8335                 /* suppress the warning for microsoft __noop operations */
8336                 case EXPR_LITERAL_MS_NOOP:            return true;
8337                 case EXPR_LITERAL_BOOLEAN:
8338                 case EXPR_LITERAL_CHARACTER:
8339                 case EXPR_LITERAL_INTEGER:
8340                 case EXPR_LITERAL_FLOATINGPOINT:
8341                 case EXPR_STRING_LITERAL:             return false;
8342
8343                 case EXPR_CALL: {
8344                         const call_expression_t *const call = &expr->call;
8345                         if (call->function->kind != EXPR_REFERENCE)
8346                                 return true;
8347
8348                         switch (call->function->reference.entity->function.btk) {
8349                                 /* FIXME: which builtins have no effect? */
8350                                 default:                      return true;
8351                         }
8352                 }
8353
8354                 /* Generate the warning if either the left or right hand side of a
8355                  * conditional expression has no effect */
8356                 case EXPR_CONDITIONAL: {
8357                         conditional_expression_t const *const cond = &expr->conditional;
8358                         expression_t             const *const t    = cond->true_expression;
8359                         return
8360                                 (t == NULL || expression_has_effect(t)) &&
8361                                 expression_has_effect(cond->false_expression);
8362                 }
8363
8364                 case EXPR_SELECT:                     return false;
8365                 case EXPR_ARRAY_ACCESS:               return false;
8366                 case EXPR_SIZEOF:                     return false;
8367                 case EXPR_CLASSIFY_TYPE:              return false;
8368                 case EXPR_ALIGNOF:                    return false;
8369
8370                 case EXPR_FUNCNAME:                   return false;
8371                 case EXPR_BUILTIN_CONSTANT_P:         return false;
8372                 case EXPR_BUILTIN_TYPES_COMPATIBLE_P: return false;
8373                 case EXPR_OFFSETOF:                   return false;
8374                 case EXPR_VA_START:                   return true;
8375                 case EXPR_VA_ARG:                     return true;
8376                 case EXPR_VA_COPY:                    return true;
8377                 case EXPR_STATEMENT:                  return true; // TODO
8378                 case EXPR_COMPOUND_LITERAL:           return false;
8379
8380                 case EXPR_UNARY_NEGATE:               return false;
8381                 case EXPR_UNARY_PLUS:                 return false;
8382                 case EXPR_UNARY_BITWISE_NEGATE:       return false;
8383                 case EXPR_UNARY_NOT:                  return false;
8384                 case EXPR_UNARY_DEREFERENCE:          return false;
8385                 case EXPR_UNARY_TAKE_ADDRESS:         return false;
8386                 case EXPR_UNARY_POSTFIX_INCREMENT:    return true;
8387                 case EXPR_UNARY_POSTFIX_DECREMENT:    return true;
8388                 case EXPR_UNARY_PREFIX_INCREMENT:     return true;
8389                 case EXPR_UNARY_PREFIX_DECREMENT:     return true;
8390
8391                 /* Treat void casts as if they have an effect in order to being able to
8392                  * suppress the warning */
8393                 case EXPR_UNARY_CAST: {
8394                         type_t *const type = skip_typeref(expr->base.type);
8395                         return is_type_void(type);
8396                 }
8397
8398                 case EXPR_UNARY_ASSUME:               return true;
8399                 case EXPR_UNARY_DELETE:               return true;
8400                 case EXPR_UNARY_DELETE_ARRAY:         return true;
8401                 case EXPR_UNARY_THROW:                return true;
8402
8403                 case EXPR_BINARY_ADD:                 return false;
8404                 case EXPR_BINARY_SUB:                 return false;
8405                 case EXPR_BINARY_MUL:                 return false;
8406                 case EXPR_BINARY_DIV:                 return false;
8407                 case EXPR_BINARY_MOD:                 return false;
8408                 case EXPR_BINARY_EQUAL:               return false;
8409                 case EXPR_BINARY_NOTEQUAL:            return false;
8410                 case EXPR_BINARY_LESS:                return false;
8411                 case EXPR_BINARY_LESSEQUAL:           return false;
8412                 case EXPR_BINARY_GREATER:             return false;
8413                 case EXPR_BINARY_GREATEREQUAL:        return false;
8414                 case EXPR_BINARY_BITWISE_AND:         return false;
8415                 case EXPR_BINARY_BITWISE_OR:          return false;
8416                 case EXPR_BINARY_BITWISE_XOR:         return false;
8417                 case EXPR_BINARY_SHIFTLEFT:           return false;
8418                 case EXPR_BINARY_SHIFTRIGHT:          return false;
8419                 case EXPR_BINARY_ASSIGN:              return true;
8420                 case EXPR_BINARY_MUL_ASSIGN:          return true;
8421                 case EXPR_BINARY_DIV_ASSIGN:          return true;
8422                 case EXPR_BINARY_MOD_ASSIGN:          return true;
8423                 case EXPR_BINARY_ADD_ASSIGN:          return true;
8424                 case EXPR_BINARY_SUB_ASSIGN:          return true;
8425                 case EXPR_BINARY_SHIFTLEFT_ASSIGN:    return true;
8426                 case EXPR_BINARY_SHIFTRIGHT_ASSIGN:   return true;
8427                 case EXPR_BINARY_BITWISE_AND_ASSIGN:  return true;
8428                 case EXPR_BINARY_BITWISE_XOR_ASSIGN:  return true;
8429                 case EXPR_BINARY_BITWISE_OR_ASSIGN:   return true;
8430
8431                 /* Only examine the right hand side of && and ||, because the left hand
8432                  * side already has the effect of controlling the execution of the right
8433                  * hand side */
8434                 case EXPR_BINARY_LOGICAL_AND:
8435                 case EXPR_BINARY_LOGICAL_OR:
8436                 /* Only examine the right hand side of a comma expression, because the left
8437                  * hand side has a separate warning */
8438                 case EXPR_BINARY_COMMA:
8439                         return expression_has_effect(expr->binary.right);
8440
8441                 case EXPR_BINARY_ISGREATER:           return false;
8442                 case EXPR_BINARY_ISGREATEREQUAL:      return false;
8443                 case EXPR_BINARY_ISLESS:              return false;
8444                 case EXPR_BINARY_ISLESSEQUAL:         return false;
8445                 case EXPR_BINARY_ISLESSGREATER:       return false;
8446                 case EXPR_BINARY_ISUNORDERED:         return false;
8447         }
8448
8449         internal_errorf(HERE, "unexpected expression");
8450 }
8451
8452 static void semantic_comma(binary_expression_t *expression)
8453 {
8454         const expression_t *const left = expression->left;
8455         if (!expression_has_effect(left)) {
8456                 position_t const *const pos = &left->base.pos;
8457                 warningf(WARN_UNUSED_VALUE, pos, "left-hand operand of comma expression has no effect");
8458         }
8459         expression->base.type = expression->right->base.type;
8460 }
8461
8462 /**
8463  * @param prec_r precedence of the right operand
8464  */
8465 #define CREATE_BINEXPR_PARSER(token_kind, binexpression_type, prec_r, sfunc) \
8466 static expression_t *parse_##binexpression_type(expression_t *left)          \
8467 {                                                                            \
8468         expression_t *binexpr = allocate_expression_zero(binexpression_type);    \
8469         binexpr->binary.left  = left;                                            \
8470         eat(token_kind);                                                         \
8471                                                                              \
8472         expression_t *right = parse_subexpression(prec_r);                       \
8473                                                                              \
8474         binexpr->binary.right = right;                                           \
8475         sfunc(&binexpr->binary);                                                 \
8476                                                                              \
8477         return binexpr;                                                          \
8478 }
8479
8480 CREATE_BINEXPR_PARSER('*',                    EXPR_BINARY_MUL,                PREC_CAST,           semantic_binexpr_arithmetic)
8481 CREATE_BINEXPR_PARSER('/',                    EXPR_BINARY_DIV,                PREC_CAST,           semantic_div)
8482 CREATE_BINEXPR_PARSER('%',                    EXPR_BINARY_MOD,                PREC_CAST,           semantic_mod)
8483 CREATE_BINEXPR_PARSER('+',                    EXPR_BINARY_ADD,                PREC_MULTIPLICATIVE, semantic_add)
8484 CREATE_BINEXPR_PARSER('-',                    EXPR_BINARY_SUB,                PREC_MULTIPLICATIVE, semantic_sub)
8485 CREATE_BINEXPR_PARSER(T_LESSLESS,             EXPR_BINARY_SHIFTLEFT,          PREC_ADDITIVE,       semantic_shift_op)
8486 CREATE_BINEXPR_PARSER(T_GREATERGREATER,       EXPR_BINARY_SHIFTRIGHT,         PREC_ADDITIVE,       semantic_shift_op)
8487 CREATE_BINEXPR_PARSER('<',                    EXPR_BINARY_LESS,               PREC_SHIFT,          semantic_comparison)
8488 CREATE_BINEXPR_PARSER('>',                    EXPR_BINARY_GREATER,            PREC_SHIFT,          semantic_comparison)
8489 CREATE_BINEXPR_PARSER(T_LESSEQUAL,            EXPR_BINARY_LESSEQUAL,          PREC_SHIFT,          semantic_comparison)
8490 CREATE_BINEXPR_PARSER(T_GREATEREQUAL,         EXPR_BINARY_GREATEREQUAL,       PREC_SHIFT,          semantic_comparison)
8491 CREATE_BINEXPR_PARSER(T_EXCLAMATIONMARKEQUAL, EXPR_BINARY_NOTEQUAL,           PREC_RELATIONAL,     semantic_comparison)
8492 CREATE_BINEXPR_PARSER(T_EQUALEQUAL,           EXPR_BINARY_EQUAL,              PREC_RELATIONAL,     semantic_comparison)
8493 CREATE_BINEXPR_PARSER('&',                    EXPR_BINARY_BITWISE_AND,        PREC_EQUALITY,       semantic_binexpr_integer)
8494 CREATE_BINEXPR_PARSER('^',                    EXPR_BINARY_BITWISE_XOR,        PREC_AND,            semantic_binexpr_integer)
8495 CREATE_BINEXPR_PARSER('|',                    EXPR_BINARY_BITWISE_OR,         PREC_XOR,            semantic_binexpr_integer)
8496 CREATE_BINEXPR_PARSER(T_ANDAND,               EXPR_BINARY_LOGICAL_AND,        PREC_OR,             semantic_logical_op)
8497 CREATE_BINEXPR_PARSER(T_PIPEPIPE,             EXPR_BINARY_LOGICAL_OR,         PREC_LOGICAL_AND,    semantic_logical_op)
8498 CREATE_BINEXPR_PARSER('=',                    EXPR_BINARY_ASSIGN,             PREC_ASSIGNMENT,     semantic_binexpr_assign)
8499 CREATE_BINEXPR_PARSER(T_PLUSEQUAL,            EXPR_BINARY_ADD_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8500 CREATE_BINEXPR_PARSER(T_MINUSEQUAL,           EXPR_BINARY_SUB_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_addsubb_assign)
8501 CREATE_BINEXPR_PARSER(T_ASTERISKEQUAL,        EXPR_BINARY_MUL_ASSIGN,         PREC_ASSIGNMENT,     semantic_arithmetic_assign)
8502 CREATE_BINEXPR_PARSER(T_SLASHEQUAL,           EXPR_BINARY_DIV_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8503 CREATE_BINEXPR_PARSER(T_PERCENTEQUAL,         EXPR_BINARY_MOD_ASSIGN,         PREC_ASSIGNMENT,     semantic_divmod_assign)
8504 CREATE_BINEXPR_PARSER(T_LESSLESSEQUAL,        EXPR_BINARY_SHIFTLEFT_ASSIGN,   PREC_ASSIGNMENT,     semantic_shift_assign)
8505 CREATE_BINEXPR_PARSER(T_GREATERGREATEREQUAL,  EXPR_BINARY_SHIFTRIGHT_ASSIGN,  PREC_ASSIGNMENT,     semantic_shift_assign)
8506 CREATE_BINEXPR_PARSER(T_ANDEQUAL,             EXPR_BINARY_BITWISE_AND_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8507 CREATE_BINEXPR_PARSER(T_PIPEEQUAL,            EXPR_BINARY_BITWISE_OR_ASSIGN,  PREC_ASSIGNMENT,     semantic_integer_assign)
8508 CREATE_BINEXPR_PARSER(T_CARETEQUAL,           EXPR_BINARY_BITWISE_XOR_ASSIGN, PREC_ASSIGNMENT,     semantic_integer_assign)
8509 CREATE_BINEXPR_PARSER(',',                    EXPR_BINARY_COMMA,              PREC_ASSIGNMENT,     semantic_comma)
8510
8511
8512 static expression_t *parse_subexpression(precedence_t precedence)
8513 {
8514         expression_parser_function_t *parser
8515                 = &expression_parsers[token.kind];
8516         expression_t                 *left;
8517
8518         if (parser->parser != NULL) {
8519                 left = parser->parser();
8520         } else {
8521                 left = parse_primary_expression();
8522         }
8523         assert(left != NULL);
8524
8525         while (true) {
8526                 parser = &expression_parsers[token.kind];
8527                 if (parser->infix_parser == NULL)
8528                         break;
8529                 if (parser->infix_precedence < precedence)
8530                         break;
8531
8532                 left = parser->infix_parser(left);
8533
8534                 assert(left != NULL);
8535         }
8536
8537         return left;
8538 }
8539
8540 /**
8541  * Parse an expression.
8542  */
8543 static expression_t *parse_expression(void)
8544 {
8545         return parse_subexpression(PREC_EXPRESSION);
8546 }
8547
8548 /**
8549  * Register a parser for a prefix-like operator.
8550  *
8551  * @param parser      the parser function
8552  * @param token_kind  the token type of the prefix token
8553  */
8554 static void register_expression_parser(parse_expression_function parser,
8555                                        int token_kind)
8556 {
8557         expression_parser_function_t *entry = &expression_parsers[token_kind];
8558
8559         assert(!entry->parser);
8560         entry->parser = parser;
8561 }
8562
8563 /**
8564  * Register a parser for an infix operator with given precedence.
8565  *
8566  * @param parser      the parser function
8567  * @param token_kind  the token type of the infix operator
8568  * @param precedence  the precedence of the operator
8569  */
8570 static void register_infix_parser(parse_expression_infix_function parser,
8571                                   int token_kind, precedence_t precedence)
8572 {
8573         expression_parser_function_t *entry = &expression_parsers[token_kind];
8574
8575         assert(!entry->infix_parser);
8576         entry->infix_parser     = parser;
8577         entry->infix_precedence = precedence;
8578 }
8579
8580 /**
8581  * Initialize the expression parsers.
8582  */
8583 static void init_expression_parsers(void)
8584 {
8585         memset(&expression_parsers, 0, sizeof(expression_parsers));
8586
8587         register_infix_parser(parse_array_expression,               '[',                    PREC_POSTFIX);
8588         register_infix_parser(parse_call_expression,                '(',                    PREC_POSTFIX);
8589         register_infix_parser(parse_select_expression,              '.',                    PREC_POSTFIX);
8590         register_infix_parser(parse_select_expression,              T_MINUSGREATER,         PREC_POSTFIX);
8591         register_infix_parser(parse_EXPR_UNARY_POSTFIX_INCREMENT,   T_PLUSPLUS,             PREC_POSTFIX);
8592         register_infix_parser(parse_EXPR_UNARY_POSTFIX_DECREMENT,   T_MINUSMINUS,           PREC_POSTFIX);
8593         register_infix_parser(parse_EXPR_BINARY_MUL,                '*',                    PREC_MULTIPLICATIVE);
8594         register_infix_parser(parse_EXPR_BINARY_DIV,                '/',                    PREC_MULTIPLICATIVE);
8595         register_infix_parser(parse_EXPR_BINARY_MOD,                '%',                    PREC_MULTIPLICATIVE);
8596         register_infix_parser(parse_EXPR_BINARY_ADD,                '+',                    PREC_ADDITIVE);
8597         register_infix_parser(parse_EXPR_BINARY_SUB,                '-',                    PREC_ADDITIVE);
8598         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT,          T_LESSLESS,             PREC_SHIFT);
8599         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT,         T_GREATERGREATER,       PREC_SHIFT);
8600         register_infix_parser(parse_EXPR_BINARY_LESS,               '<',                    PREC_RELATIONAL);
8601         register_infix_parser(parse_EXPR_BINARY_GREATER,            '>',                    PREC_RELATIONAL);
8602         register_infix_parser(parse_EXPR_BINARY_LESSEQUAL,          T_LESSEQUAL,            PREC_RELATIONAL);
8603         register_infix_parser(parse_EXPR_BINARY_GREATEREQUAL,       T_GREATEREQUAL,         PREC_RELATIONAL);
8604         register_infix_parser(parse_EXPR_BINARY_EQUAL,              T_EQUALEQUAL,           PREC_EQUALITY);
8605         register_infix_parser(parse_EXPR_BINARY_NOTEQUAL,           T_EXCLAMATIONMARKEQUAL, PREC_EQUALITY);
8606         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND,        '&',                    PREC_AND);
8607         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR,        '^',                    PREC_XOR);
8608         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR,         '|',                    PREC_OR);
8609         register_infix_parser(parse_EXPR_BINARY_LOGICAL_AND,        T_ANDAND,               PREC_LOGICAL_AND);
8610         register_infix_parser(parse_EXPR_BINARY_LOGICAL_OR,         T_PIPEPIPE,             PREC_LOGICAL_OR);
8611         register_infix_parser(parse_conditional_expression,         '?',                    PREC_CONDITIONAL);
8612         register_infix_parser(parse_EXPR_BINARY_ASSIGN,             '=',                    PREC_ASSIGNMENT);
8613         register_infix_parser(parse_EXPR_BINARY_ADD_ASSIGN,         T_PLUSEQUAL,            PREC_ASSIGNMENT);
8614         register_infix_parser(parse_EXPR_BINARY_SUB_ASSIGN,         T_MINUSEQUAL,           PREC_ASSIGNMENT);
8615         register_infix_parser(parse_EXPR_BINARY_MUL_ASSIGN,         T_ASTERISKEQUAL,        PREC_ASSIGNMENT);
8616         register_infix_parser(parse_EXPR_BINARY_DIV_ASSIGN,         T_SLASHEQUAL,           PREC_ASSIGNMENT);
8617         register_infix_parser(parse_EXPR_BINARY_MOD_ASSIGN,         T_PERCENTEQUAL,         PREC_ASSIGNMENT);
8618         register_infix_parser(parse_EXPR_BINARY_SHIFTLEFT_ASSIGN,   T_LESSLESSEQUAL,        PREC_ASSIGNMENT);
8619         register_infix_parser(parse_EXPR_BINARY_SHIFTRIGHT_ASSIGN,  T_GREATERGREATEREQUAL,  PREC_ASSIGNMENT);
8620         register_infix_parser(parse_EXPR_BINARY_BITWISE_AND_ASSIGN, T_ANDEQUAL,             PREC_ASSIGNMENT);
8621         register_infix_parser(parse_EXPR_BINARY_BITWISE_OR_ASSIGN,  T_PIPEEQUAL,            PREC_ASSIGNMENT);
8622         register_infix_parser(parse_EXPR_BINARY_BITWISE_XOR_ASSIGN, T_CARETEQUAL,           PREC_ASSIGNMENT);
8623         register_infix_parser(parse_EXPR_BINARY_COMMA,              ',',                    PREC_EXPRESSION);
8624
8625         register_expression_parser(parse_EXPR_UNARY_NEGATE,           '-');
8626         register_expression_parser(parse_EXPR_UNARY_PLUS,             '+');
8627         register_expression_parser(parse_EXPR_UNARY_NOT,              '!');
8628         register_expression_parser(parse_EXPR_UNARY_BITWISE_NEGATE,   '~');
8629         register_expression_parser(parse_EXPR_UNARY_DEREFERENCE,      '*');
8630         register_expression_parser(parse_EXPR_UNARY_TAKE_ADDRESS,     '&');
8631         register_expression_parser(parse_EXPR_UNARY_PREFIX_INCREMENT, T_PLUSPLUS);
8632         register_expression_parser(parse_EXPR_UNARY_PREFIX_DECREMENT, T_MINUSMINUS);
8633         register_expression_parser(parse_sizeof,                      T_sizeof);
8634         register_expression_parser(parse_alignof,                     T__Alignof);
8635         register_expression_parser(parse_extension,                   T___extension__);
8636         register_expression_parser(parse_builtin_classify_type,       T___builtin_classify_type);
8637         register_expression_parser(parse_delete,                      T_delete);
8638         register_expression_parser(parse_throw,                       T_throw);
8639 }
8640
8641 /**
8642  * Parse a asm statement arguments specification.
8643  */
8644 static void parse_asm_arguments(asm_argument_t **anchor, bool const is_out)
8645 {
8646         if (token.kind == T_STRING_LITERAL || token.kind == '[') {
8647                 add_anchor_token(',');
8648                 do {
8649                         asm_argument_t *argument = allocate_ast_zero(sizeof(argument[0]));
8650
8651                         add_anchor_token(')');
8652                         add_anchor_token('(');
8653                         add_anchor_token(T_STRING_LITERAL);
8654
8655                         if (accept('[')) {
8656                                 add_anchor_token(']');
8657                                 argument->symbol = expect_identifier("while parsing asm argument", NULL);
8658                                 rem_anchor_token(']');
8659                                 expect(']');
8660                         }
8661
8662                         rem_anchor_token(T_STRING_LITERAL);
8663                         argument->constraints = parse_string_literals("asm argument");
8664                         rem_anchor_token('(');
8665                         expect('(');
8666                         expression_t *expression = parse_expression();
8667                         if (is_out) {
8668                                 /* Ugly GCC stuff: Allow lvalue casts.  Skip casts, when they do not
8669                                  * change size or type representation (e.g. int -> long is ok, but
8670                                  * int -> float is not) */
8671                                 if (expression->kind == EXPR_UNARY_CAST) {
8672                                         type_t      *const type = expression->base.type;
8673                                         type_kind_t  const kind = type->kind;
8674                                         if (kind == TYPE_ATOMIC || kind == TYPE_POINTER) {
8675                                                 unsigned flags;
8676                                                 unsigned size;
8677                                                 if (kind == TYPE_ATOMIC) {
8678                                                         atomic_type_kind_t const akind = type->atomic.akind;
8679                                                         flags = get_atomic_type_flags(akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8680                                                         size  = get_atomic_type_size(akind);
8681                                                 } else {
8682                                                         flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8683                                                         size  = get_type_size(type_void_ptr);
8684                                                 }
8685
8686                                                 do {
8687                                                         expression_t *const value      = expression->unary.value;
8688                                                         type_t       *const value_type = value->base.type;
8689                                                         type_kind_t   const value_kind = value_type->kind;
8690
8691                                                         unsigned value_flags;
8692                                                         unsigned value_size;
8693                                                         if (value_kind == TYPE_ATOMIC) {
8694                                                                 atomic_type_kind_t const value_akind = value_type->atomic.akind;
8695                                                                 value_flags = get_atomic_type_flags(value_akind) & ~ATOMIC_TYPE_FLAG_SIGNED;
8696                                                                 value_size  = get_atomic_type_size(value_akind);
8697                                                         } else if (value_kind == TYPE_POINTER) {
8698                                                                 value_flags = ATOMIC_TYPE_FLAG_INTEGER | ATOMIC_TYPE_FLAG_ARITHMETIC;
8699                                                                 value_size  = get_type_size(type_void_ptr);
8700                                                         } else {
8701                                                                 break;
8702                                                         }
8703
8704                                                         if (value_flags != flags || value_size != size)
8705                                                                 break;
8706
8707                                                         expression = value;
8708                                                 } while (expression->kind == EXPR_UNARY_CAST);
8709                                         }
8710                                 }
8711
8712                                 if (!is_lvalue(expression))
8713                                         errorf(&expression->base.pos,
8714                                                "asm output argument is not an lvalue");
8715
8716                                 if (argument->constraints.begin[0] == '=')
8717                                         determine_lhs_ent(expression, NULL);
8718                                 else
8719                                         mark_vars_read(expression, NULL);
8720                         } else {
8721                                 mark_vars_read(expression, NULL);
8722                         }
8723                         argument->expression = expression;
8724                         rem_anchor_token(')');
8725                         expect(')');
8726
8727                         set_address_taken(expression, true);
8728
8729                         *anchor = argument;
8730                         anchor  = &argument->next;
8731                 } while (accept(','));
8732                 rem_anchor_token(',');
8733         }
8734 }
8735
8736 /**
8737  * Parse a asm statement clobber specification.
8738  */
8739 static void parse_asm_clobbers(asm_clobber_t **anchor)
8740 {
8741         if (token.kind == T_STRING_LITERAL) {
8742                 add_anchor_token(',');
8743                 do {
8744                         asm_clobber_t *clobber = allocate_ast_zero(sizeof(clobber[0]));
8745                         clobber->clobber       = parse_string_literals(NULL);
8746
8747                         *anchor = clobber;
8748                         anchor  = &clobber->next;
8749                 } while (accept(','));
8750                 rem_anchor_token(',');
8751         }
8752 }
8753
8754 static void parse_asm_labels(asm_label_t **anchor)
8755 {
8756         if (token.kind == T_IDENTIFIER) {
8757                 add_anchor_token(',');
8758                 do {
8759                         label_t *const label = get_label("while parsing 'asm goto' labels");
8760                         if (label) {
8761                                 asm_label_t *const asm_label = allocate_ast_zero(sizeof(*asm_label));
8762                                 asm_label->label = label;
8763
8764                                 *anchor = asm_label;
8765                                 anchor  = &asm_label->next;
8766                         }
8767                 } while (accept(','));
8768                 rem_anchor_token(',');
8769         }
8770 }
8771
8772 /**
8773  * Parse an asm statement.
8774  */
8775 static statement_t *parse_asm_statement(void)
8776 {
8777         statement_t     *statement     = allocate_statement_zero(STATEMENT_ASM);
8778         asm_statement_t *asm_statement = &statement->asms;
8779
8780         eat(T_asm);
8781         add_anchor_token(')');
8782         add_anchor_token(':');
8783         add_anchor_token(T_STRING_LITERAL);
8784
8785         if (accept(T_volatile))
8786                 asm_statement->is_volatile = true;
8787
8788         bool const asm_goto = accept(T_goto);
8789
8790         expect('(');
8791         rem_anchor_token(T_STRING_LITERAL);
8792         asm_statement->asm_text = parse_string_literals("asm statement");
8793
8794         if (accept(':')) parse_asm_arguments(&asm_statement->outputs, true);
8795         if (accept(':')) parse_asm_arguments(&asm_statement->inputs, false);
8796         if (accept(':')) parse_asm_clobbers( &asm_statement->clobbers);
8797
8798         rem_anchor_token(':');
8799         if (accept(':')) {
8800                 if (!asm_goto)
8801                         warningf(WARN_OTHER, &statement->base.pos, "assembler statement with labels should be 'asm goto'");
8802                 parse_asm_labels(&asm_statement->labels);
8803                 if (asm_statement->labels)
8804                         errorf(&statement->base.pos, "'asm goto' not supported");
8805         } else {
8806                 if (asm_goto)
8807                         warningf(WARN_OTHER, &statement->base.pos, "'asm goto' without labels");
8808         }
8809
8810         rem_anchor_token(')');
8811         expect(')');
8812         expect(';');
8813
8814         if (asm_statement->outputs == NULL) {
8815                 /* GCC: An 'asm' instruction without any output operands will be treated
8816                  * identically to a volatile 'asm' instruction. */
8817                 asm_statement->is_volatile = true;
8818         }
8819
8820         return statement;
8821 }
8822
8823 static statement_t *parse_label_inner_statement(statement_t const *const label, char const *const label_kind)
8824 {
8825         statement_t *inner_stmt;
8826         switch (token.kind) {
8827                 case '}':
8828                         errorf(&label->base.pos, "%s at end of compound statement", label_kind);
8829                         inner_stmt = create_error_statement();
8830                         break;
8831
8832                 case ';':
8833                         if (label->kind == STATEMENT_LABEL) {
8834                                 /* Eat an empty statement here, to avoid the warning about an empty
8835                                  * statement after a label.  label:; is commonly used to have a label
8836                                  * before a closing brace. */
8837                                 inner_stmt = create_empty_statement();
8838                                 eat(';');
8839                                 break;
8840                         }
8841                         /* FALLTHROUGH */
8842
8843                 default:
8844                         inner_stmt = parse_statement();
8845                         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
8846                         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
8847                         if (inner_stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
8848                                 errorf(&inner_stmt->base.pos, "declaration after %s", label_kind);
8849                         }
8850                         break;
8851         }
8852         return inner_stmt;
8853 }
8854
8855 /**
8856  * Parse a case statement.
8857  */
8858 static statement_t *parse_case_statement(void)
8859 {
8860         statement_t *const statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8861         position_t  *const pos       = &statement->base.pos;
8862
8863         eat(T_case);
8864         add_anchor_token(':');
8865
8866         expression_t *expression = parse_expression();
8867         type_t *expression_type = expression->base.type;
8868         type_t *skipped         = skip_typeref(expression_type);
8869         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8870                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8871                        expression, expression_type);
8872         }
8873
8874         type_t *type = expression_type;
8875         if (current_switch != NULL) {
8876                 type_t *switch_type = current_switch->expression->base.type;
8877                 if (is_type_valid(switch_type)) {
8878                         expression = create_implicit_cast(expression, switch_type);
8879                 }
8880         }
8881
8882         statement->case_label.expression = expression;
8883         expression_classification_t const expr_class = is_constant_expression(expression);
8884         if (expr_class != EXPR_CLASS_CONSTANT) {
8885                 if (expr_class != EXPR_CLASS_ERROR) {
8886                         errorf(pos, "case label does not reduce to an integer constant");
8887                 }
8888                 statement->case_label.is_bad = true;
8889         } else {
8890                 ir_tarval *val = fold_constant_to_tarval(expression);
8891                 statement->case_label.first_case = val;
8892                 statement->case_label.last_case  = val;
8893         }
8894
8895         if (GNU_MODE) {
8896                 if (accept(T_DOTDOTDOT)) {
8897                         expression_t *end_range = parse_expression();
8898                         expression_type = expression->base.type;
8899                         skipped         = skip_typeref(expression_type);
8900                         if (!is_type_integer(skipped) && is_type_valid(skipped)) {
8901                                 errorf(pos, "case expression '%E' must have integer type but has type '%T'",
8902                                            expression, expression_type);
8903                         }
8904
8905                         end_range = create_implicit_cast(end_range, type);
8906                         statement->case_label.end_range = end_range;
8907                         expression_classification_t const end_class = is_constant_expression(end_range);
8908                         if (end_class != EXPR_CLASS_CONSTANT) {
8909                                 if (end_class != EXPR_CLASS_ERROR) {
8910                                         errorf(pos, "case range does not reduce to an integer constant");
8911                                 }
8912                                 statement->case_label.is_bad = true;
8913                         } else {
8914                                 ir_tarval *val = fold_constant_to_tarval(end_range);
8915                                 statement->case_label.last_case = val;
8916
8917                                 if (tarval_cmp(val, statement->case_label.first_case)
8918                                     == ir_relation_less) {
8919                                         statement->case_label.is_empty_range = true;
8920                                         warningf(WARN_OTHER, pos, "empty range specified");
8921                                 }
8922                         }
8923                 }
8924         }
8925
8926         PUSH_PARENT(statement);
8927
8928         rem_anchor_token(':');
8929         expect(':');
8930
8931         if (current_switch != NULL) {
8932                 if (! statement->case_label.is_bad) {
8933                         /* Check for duplicate case values */
8934                         case_label_statement_t *c = &statement->case_label;
8935                         for (case_label_statement_t *l = current_switch->first_case; l != NULL; l = l->next) {
8936                                 if (l->is_bad || l->is_empty_range || l->expression == NULL)
8937                                         continue;
8938
8939                                 if (c->last_case < l->first_case || c->first_case > l->last_case)
8940                                         continue;
8941
8942                                 errorf(pos, "duplicate case value (previously used %P)",
8943                                        &l->base.pos);
8944                                 break;
8945                         }
8946                 }
8947                 /* link all cases into the switch statement */
8948                 if (current_switch->last_case == NULL) {
8949                         current_switch->first_case      = &statement->case_label;
8950                 } else {
8951                         current_switch->last_case->next = &statement->case_label;
8952                 }
8953                 current_switch->last_case = &statement->case_label;
8954         } else {
8955                 errorf(pos, "case label not within a switch statement");
8956         }
8957
8958         statement->case_label.statement = parse_label_inner_statement(statement, "case label");
8959
8960         POP_PARENT();
8961         return statement;
8962 }
8963
8964 /**
8965  * Parse a default statement.
8966  */
8967 static statement_t *parse_default_statement(void)
8968 {
8969         statement_t *statement = allocate_statement_zero(STATEMENT_CASE_LABEL);
8970
8971         eat(T_default);
8972
8973         PUSH_PARENT(statement);
8974
8975         expect(':');
8976
8977         if (current_switch != NULL) {
8978                 const case_label_statement_t *def_label = current_switch->default_label;
8979                 if (def_label != NULL) {
8980                         errorf(&statement->base.pos, "multiple default labels in one switch (previous declared %P)", &def_label->base.pos);
8981                 } else {
8982                         current_switch->default_label = &statement->case_label;
8983
8984                         /* link all cases into the switch statement */
8985                         if (current_switch->last_case == NULL) {
8986                                 current_switch->first_case      = &statement->case_label;
8987                         } else {
8988                                 current_switch->last_case->next = &statement->case_label;
8989                         }
8990                         current_switch->last_case = &statement->case_label;
8991                 }
8992         } else {
8993                 errorf(&statement->base.pos,
8994                        "'default' label not within a switch statement");
8995         }
8996
8997         statement->case_label.statement = parse_label_inner_statement(statement, "default label");
8998
8999         POP_PARENT();
9000         return statement;
9001 }
9002
9003 /**
9004  * Parse a label statement.
9005  */
9006 static statement_t *parse_label_statement(void)
9007 {
9008         statement_t *const statement = allocate_statement_zero(STATEMENT_LABEL);
9009         label_t     *const label     = get_label(NULL /* Cannot fail, token is T_IDENTIFIER. */);
9010         statement->label.label = label;
9011
9012         PUSH_PARENT(statement);
9013
9014         /* if statement is already set then the label is defined twice,
9015          * otherwise it was just mentioned in a goto/local label declaration so far
9016          */
9017         position_t const* const pos = &statement->base.pos;
9018         if (label->statement != NULL) {
9019                 errorf(pos, "duplicate '%N' (declared %P)", (entity_t const*)label, &label->base.pos);
9020         } else {
9021                 label->base.pos  = *pos;
9022                 label->statement = statement;
9023                 label->n_users  += 1;
9024         }
9025
9026         eat(':');
9027
9028         if (token.kind == T___attribute__ && !(c_mode & _CXX)) {
9029                 parse_attributes(NULL); // TODO process attributes
9030         }
9031
9032         statement->label.statement = parse_label_inner_statement(statement, "label");
9033
9034         /* remember the labels in a list for later checking */
9035         *label_anchor = &statement->label;
9036         label_anchor  = &statement->label.next;
9037
9038         POP_PARENT();
9039         return statement;
9040 }
9041
9042 static statement_t *parse_inner_statement(void)
9043 {
9044         statement_t *const stmt = parse_statement();
9045         /* ISO/IEC  9899:1999(E) §6.8:1/6.8.2:1  Declarations are no statements */
9046         /* ISO/IEC 14882:1998(E) §6:1/§6.7       Declarations are statements */
9047         if (stmt->kind == STATEMENT_DECLARATION && !(c_mode & _CXX)) {
9048                 errorf(&stmt->base.pos, "declaration as inner statement, use {}");
9049         }
9050         return stmt;
9051 }
9052
9053 /**
9054  * Parse an expression in parentheses and mark its variables as read.
9055  */
9056 static expression_t *parse_condition(void)
9057 {
9058         add_anchor_token(')');
9059         expect('(');
9060         expression_t *const expr = parse_expression();
9061         mark_vars_read(expr, NULL);
9062         rem_anchor_token(')');
9063         expect(')');
9064         return expr;
9065 }
9066
9067 /**
9068  * Parse an if statement.
9069  */
9070 static statement_t *parse_if(void)
9071 {
9072         statement_t *statement = allocate_statement_zero(STATEMENT_IF);
9073
9074         eat(T_if);
9075
9076         PUSH_PARENT(statement);
9077         PUSH_SCOPE_STATEMENT(&statement->ifs.scope);
9078
9079         add_anchor_token(T_else);
9080
9081         expression_t *const expr = parse_condition();
9082         statement->ifs.condition = expr;
9083         /* §6.8.4.1:1  The controlling expression of an if statement shall have
9084          *             scalar type. */
9085         semantic_condition(expr, "condition of 'if'-statment");
9086
9087         statement_t *const true_stmt = parse_inner_statement();
9088         statement->ifs.true_statement = true_stmt;
9089         rem_anchor_token(T_else);
9090
9091         if (true_stmt->kind == STATEMENT_EMPTY) {
9092                 warningf(WARN_EMPTY_BODY, HERE,
9093                         "suggest braces around empty body in an ‘if’ statement");
9094         }
9095
9096         if (accept(T_else)) {
9097                 statement->ifs.false_statement = parse_inner_statement();
9098
9099                 if (statement->ifs.false_statement->kind == STATEMENT_EMPTY) {
9100                         warningf(WARN_EMPTY_BODY, HERE,
9101                                         "suggest braces around empty body in an ‘if’ statement");
9102                 }
9103         } else if (true_stmt->kind == STATEMENT_IF &&
9104                         true_stmt->ifs.false_statement != NULL) {
9105                 position_t const *const pos = &true_stmt->base.pos;
9106                 warningf(WARN_PARENTHESES, pos, "suggest explicit braces to avoid ambiguous 'else'");
9107         }
9108
9109         POP_SCOPE();
9110         POP_PARENT();
9111         return statement;
9112 }
9113
9114 /**
9115  * Check that all enums are handled in a switch.
9116  *
9117  * @param statement  the switch statement to check
9118  */
9119 static void check_enum_cases(const switch_statement_t *statement)
9120 {
9121         if (!is_warn_on(WARN_SWITCH_ENUM))
9122                 return;
9123         type_t *type = skip_typeref(statement->expression->base.type);
9124         if (! is_type_enum(type))
9125                 return;
9126         enum_type_t *enumt = &type->enumt;
9127
9128         /* if we have a default, no warnings */
9129         if (statement->default_label != NULL)
9130                 return;
9131
9132         determine_enum_values(enumt);
9133
9134         /* FIXME: calculation of value should be done while parsing */
9135         /* TODO: quadratic algorithm here. Change to an n log n one */
9136         const entity_t *entry = enumt->enume->base.next;
9137         for (; entry != NULL && entry->kind == ENTITY_ENUM_VALUE;
9138              entry = entry->base.next) {
9139                 ir_tarval *value = entry->enum_value.tv;
9140                 bool       found = false;
9141                 for (const case_label_statement_t *l = statement->first_case; l != NULL;
9142                      l = l->next) {
9143                         if (l->expression == NULL)
9144                                 continue;
9145                         if (l->first_case == l->last_case && l->first_case != value)
9146                                 continue;
9147                         if ((tarval_cmp(l->first_case, value) & ir_relation_less_equal)
9148                          && (tarval_cmp(value, l->last_case) & ir_relation_less_equal)) {
9149                                 found = true;
9150                                 break;
9151                         }
9152                 }
9153                 if (!found) {
9154                         position_t const *const pos = &statement->base.pos;
9155                         warningf(WARN_SWITCH_ENUM, pos, "'%N' not handled in switch", entry);
9156                 }
9157         }
9158 }
9159
9160 /**
9161  * Parse a switch statement.
9162  */
9163 static statement_t *parse_switch(void)
9164 {
9165         statement_t *statement = allocate_statement_zero(STATEMENT_SWITCH);
9166
9167         eat(T_switch);
9168
9169         PUSH_PARENT(statement);
9170         PUSH_SCOPE_STATEMENT(&statement->switchs.scope);
9171
9172         expression_t *const expr = parse_condition();
9173         type_t       *      type = skip_typeref(expr->base.type);
9174         if (is_type_integer(type)) {
9175                 type = promote_integer(type);
9176                 if (get_akind_rank(get_akind(type)) >= get_akind_rank(ATOMIC_TYPE_LONG)) {
9177                         warningf(WARN_TRADITIONAL, &expr->base.pos,
9178                                  "'%T' switch expression not converted to '%T' in ISO C",
9179                                  type, type_int);
9180                 }
9181         } else if (is_type_valid(type)) {
9182                 errorf(&expr->base.pos, "switch quantity is not an integer, but '%T'",
9183                        type);
9184                 type = type_error_type;
9185         }
9186         statement->switchs.expression = create_implicit_cast(expr, type);
9187
9188         switch_statement_t *rem = current_switch;
9189         current_switch          = &statement->switchs;
9190         statement->switchs.body = parse_inner_statement();
9191         current_switch          = rem;
9192
9193         if (statement->switchs.default_label == NULL) {
9194                 warningf(WARN_SWITCH_DEFAULT, &statement->base.pos, "switch has no default case");
9195         }
9196         check_enum_cases(&statement->switchs);
9197
9198         POP_SCOPE();
9199         POP_PARENT();
9200         return statement;
9201 }
9202
9203 static statement_t *parse_loop_body(statement_t *const loop)
9204 {
9205         statement_t *const rem = current_loop;
9206         current_loop = loop;
9207
9208         statement_t *const body = parse_inner_statement();
9209
9210         current_loop = rem;
9211         return body;
9212 }
9213
9214 /**
9215  * Parse a while statement.
9216  */
9217 static statement_t *parse_while(void)
9218 {
9219         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9220
9221         eat(T_while);
9222
9223         PUSH_PARENT(statement);
9224         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9225
9226         expression_t *const cond = parse_condition();
9227         statement->fors.condition = cond;
9228         /* §6.8.5:2    The controlling expression of an iteration statement shall
9229          *             have scalar type. */
9230         semantic_condition(cond, "condition of 'while'-statement");
9231
9232         statement->fors.body = parse_loop_body(statement);
9233
9234         POP_SCOPE();
9235         POP_PARENT();
9236         return statement;
9237 }
9238
9239 /**
9240  * Parse a do statement.
9241  */
9242 static statement_t *parse_do(void)
9243 {
9244         statement_t *statement = allocate_statement_zero(STATEMENT_DO_WHILE);
9245
9246         eat(T_do);
9247
9248         PUSH_PARENT(statement);
9249         PUSH_SCOPE_STATEMENT(&statement->do_while.scope);
9250
9251         add_anchor_token(T_while);
9252         statement->do_while.body = parse_loop_body(statement);
9253         rem_anchor_token(T_while);
9254
9255         expect(T_while);
9256         expression_t *const cond = parse_condition();
9257         statement->do_while.condition = cond;
9258         /* §6.8.5:2    The controlling expression of an iteration statement shall
9259          *             have scalar type. */
9260         semantic_condition(cond, "condition of 'do-while'-statement");
9261         expect(';');
9262
9263         POP_SCOPE();
9264         POP_PARENT();
9265         return statement;
9266 }
9267
9268 /**
9269  * Parse a for statement.
9270  */
9271 static statement_t *parse_for(void)
9272 {
9273         statement_t *statement = allocate_statement_zero(STATEMENT_FOR);
9274
9275         eat(T_for);
9276
9277         PUSH_PARENT(statement);
9278         PUSH_SCOPE_STATEMENT(&statement->fors.scope);
9279
9280         add_anchor_token(')');
9281         expect('(');
9282
9283         PUSH_EXTENSION();
9284
9285         if (accept(';')) {
9286         } else if (is_declaration_specifier(&token)) {
9287                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9288         } else {
9289                 add_anchor_token(';');
9290                 expression_t *const init = parse_expression();
9291                 statement->fors.initialisation = init;
9292                 mark_vars_read(init, ENT_ANY);
9293                 if (!expression_has_effect(init)) {
9294                         warningf(WARN_UNUSED_VALUE, &init->base.pos, "initialisation of 'for'-statement has no effect");
9295                 }
9296                 rem_anchor_token(';');
9297                 expect(';');
9298         }
9299
9300         POP_EXTENSION();
9301
9302         if (token.kind != ';') {
9303                 add_anchor_token(';');
9304                 expression_t *const cond = parse_expression();
9305                 statement->fors.condition = cond;
9306                 /* §6.8.5:2    The controlling expression of an iteration statement
9307                  *             shall have scalar type. */
9308                 semantic_condition(cond, "condition of 'for'-statement");
9309                 mark_vars_read(cond, NULL);
9310                 rem_anchor_token(';');
9311         }
9312         expect(';');
9313         if (token.kind != ')') {
9314                 expression_t *const step = parse_expression();
9315                 statement->fors.step = step;
9316                 mark_vars_read(step, ENT_ANY);
9317                 if (!expression_has_effect(step)) {
9318                         warningf(WARN_UNUSED_VALUE, &step->base.pos, "step of 'for'-statement has no effect");
9319                 }
9320         }
9321         rem_anchor_token(')');
9322         expect(')');
9323         statement->fors.body = parse_loop_body(statement);
9324
9325         POP_SCOPE();
9326         POP_PARENT();
9327         return statement;
9328 }
9329
9330 /**
9331  * Parse a goto statement.
9332  */
9333 static statement_t *parse_goto(void)
9334 {
9335         statement_t *statement;
9336         if (GNU_MODE && look_ahead(1)->kind == '*') {
9337                 statement = allocate_statement_zero(STATEMENT_COMPUTED_GOTO);
9338                 eat(T_goto);
9339                 eat('*');
9340
9341                 expression_t *expression = parse_expression();
9342                 mark_vars_read(expression, NULL);
9343
9344                 /* Argh: although documentation says the expression must be of type void*,
9345                  * gcc accepts anything that can be casted into void* without error */
9346                 type_t *type = expression->base.type;
9347
9348                 if (type != type_error_type) {
9349                         if (!is_type_pointer(type) && !is_type_integer(type)) {
9350                                 errorf(&expression->base.pos, "cannot convert to a pointer type");
9351                         } else if (type != type_void_ptr) {
9352                                 warningf(WARN_OTHER, &expression->base.pos, "type of computed goto expression should be 'void*' not '%T'", type);
9353                         }
9354                         expression = create_implicit_cast(expression, type_void_ptr);
9355                 }
9356
9357                 statement->computed_goto.expression = expression;
9358         } else {
9359                 statement = allocate_statement_zero(STATEMENT_GOTO);
9360                 eat(T_goto);
9361
9362                 label_t *const label = get_label("while parsing goto");
9363                 if (label) {
9364                         label->n_users        += 1;
9365                         label->used            = true;
9366                         statement->gotos.label = label;
9367
9368                         /* remember the goto's in a list for later checking */
9369                         *goto_anchor = &statement->gotos;
9370                         goto_anchor  = &statement->gotos.next;
9371                 } else {
9372                         statement->gotos.label = &allocate_entity_zero(ENTITY_LABEL, NAMESPACE_LABEL, sym_anonymous, &builtin_position)->label;
9373                 }
9374         }
9375
9376         expect(';');
9377         return statement;
9378 }
9379
9380 /**
9381  * Parse a continue statement.
9382  */
9383 static statement_t *parse_continue(void)
9384 {
9385         if (current_loop == NULL) {
9386                 errorf(HERE, "continue statement not within loop");
9387         }
9388
9389         statement_t *statement = allocate_statement_zero(STATEMENT_CONTINUE);
9390
9391         eat(T_continue);
9392         expect(';');
9393         return statement;
9394 }
9395
9396 /**
9397  * Parse a break statement.
9398  */
9399 static statement_t *parse_break(void)
9400 {
9401         if (current_switch == NULL && current_loop == NULL) {
9402                 errorf(HERE, "break statement not within loop or switch");
9403         }
9404
9405         statement_t *statement = allocate_statement_zero(STATEMENT_BREAK);
9406
9407         eat(T_break);
9408         expect(';');
9409         return statement;
9410 }
9411
9412 /**
9413  * Parse a __leave statement.
9414  */
9415 static statement_t *parse_leave_statement(void)
9416 {
9417         if (current_try == NULL) {
9418                 errorf(HERE, "__leave statement not within __try");
9419         }
9420
9421         statement_t *statement = allocate_statement_zero(STATEMENT_LEAVE);
9422
9423         eat(T___leave);
9424         expect(';');
9425         return statement;
9426 }
9427
9428 /**
9429  * Check if a given entity represents a local variable.
9430  */
9431 static bool is_local_variable(const entity_t *entity)
9432 {
9433         if (entity->kind != ENTITY_VARIABLE)
9434                 return false;
9435
9436         switch ((storage_class_tag_t) entity->declaration.storage_class) {
9437         case STORAGE_CLASS_AUTO:
9438         case STORAGE_CLASS_REGISTER: {
9439                 const type_t *type = skip_typeref(entity->declaration.type);
9440                 if (is_type_function(type)) {
9441                         return false;
9442                 } else {
9443                         return true;
9444                 }
9445         }
9446         default:
9447                 return false;
9448         }
9449 }
9450
9451 /**
9452  * Check if a given expression represents a local variable.
9453  */
9454 static bool expression_is_local_variable(const expression_t *expression)
9455 {
9456         if (expression->base.kind != EXPR_REFERENCE) {
9457                 return false;
9458         }
9459         const entity_t *entity = expression->reference.entity;
9460         return is_local_variable(entity);
9461 }
9462
9463 static void err_or_warn(position_t const *const pos, char const *const msg)
9464 {
9465         if (c_mode & _CXX || strict_mode) {
9466                 errorf(pos, msg);
9467         } else {
9468                 warningf(WARN_OTHER, pos, msg);
9469         }
9470 }
9471
9472 /**
9473  * Parse a return statement.
9474  */
9475 static statement_t *parse_return(void)
9476 {
9477         statement_t *statement = allocate_statement_zero(STATEMENT_RETURN);
9478         eat(T_return);
9479
9480         expression_t *return_value = NULL;
9481         if (token.kind != ';') {
9482                 return_value = parse_expression();
9483                 mark_vars_read(return_value, NULL);
9484         }
9485
9486         const type_t *const func_type = skip_typeref(current_function->base.type);
9487         assert(is_type_function(func_type));
9488         type_t *const return_type = skip_typeref(func_type->function.return_type);
9489
9490         position_t const *const pos = &statement->base.pos;
9491         if (return_value != NULL) {
9492                 type_t *return_value_type = skip_typeref(return_value->base.type);
9493
9494                 if (is_type_void(return_type)) {
9495                         if (!is_type_void(return_value_type)) {
9496                                 /* ISO/IEC 14882:1998(E) §6.6.3:2 */
9497                                 /* Only warn in C mode, because GCC does the same */
9498                                 err_or_warn(pos, "'return' with a value, in function returning 'void'");
9499                         } else if (!(c_mode & _CXX)) { /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9500                                 /* Only warn in C mode, because GCC does the same */
9501                                 err_or_warn(pos, "'return' with expression in function returning 'void'");
9502                         }
9503                 } else {
9504                         assign_error_t error = semantic_assign(return_type, return_value);
9505                         report_assign_error(error, return_type, return_value, "'return'",
9506                                             pos);
9507                 }
9508                 return_value = create_implicit_cast(return_value, return_type);
9509                 /* check for returning address of a local var */
9510                 if (return_value != NULL && return_value->base.kind == EXPR_UNARY_TAKE_ADDRESS) {
9511                         const expression_t *expression = return_value->unary.value;
9512                         if (expression_is_local_variable(expression)) {
9513                                 warningf(WARN_OTHER, pos, "function returns address of local variable");
9514                         }
9515                 }
9516         } else if (!is_type_void(return_type)) {
9517                 /* ISO/IEC 14882:1998(E) §6.6.3:3 */
9518                 err_or_warn(pos, "'return' without value, in function returning non-void");
9519         }
9520         statement->returns.value = return_value;
9521
9522         expect(';');
9523         return statement;
9524 }
9525
9526 /**
9527  * Parse a declaration statement.
9528  */
9529 static statement_t *parse_declaration_statement(void)
9530 {
9531         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9532
9533         entity_t *before = current_scope->last_entity;
9534         if (GNU_MODE) {
9535                 parse_external_declaration();
9536         } else {
9537                 parse_declaration(record_entity, DECL_FLAGS_NONE);
9538         }
9539
9540         declaration_statement_t *const decl  = &statement->declaration;
9541         entity_t                *const begin =
9542                 before != NULL ? before->base.next : current_scope->entities;
9543         decl->declarations_begin = begin;
9544         decl->declarations_end   = begin != NULL ? current_scope->last_entity : NULL;
9545
9546         return statement;
9547 }
9548
9549 /**
9550  * Parse an expression statement, i.e. expr ';'.
9551  */
9552 static statement_t *parse_expression_statement(void)
9553 {
9554         statement_t *statement = allocate_statement_zero(STATEMENT_EXPRESSION);
9555
9556         expression_t *const expr         = parse_expression();
9557         statement->expression.expression = expr;
9558         mark_vars_read(expr, ENT_ANY);
9559
9560         expect(';');
9561         return statement;
9562 }
9563
9564 /**
9565  * Parse a microsoft __try { } __finally { } or
9566  * __try{ } __except() { }
9567  */
9568 static statement_t *parse_ms_try_statment(void)
9569 {
9570         statement_t *statement = allocate_statement_zero(STATEMENT_MS_TRY);
9571         eat(T___try);
9572
9573         PUSH_PARENT(statement);
9574
9575         ms_try_statement_t *rem = current_try;
9576         current_try = &statement->ms_try;
9577         statement->ms_try.try_statement = parse_compound_statement(false);
9578         current_try = rem;
9579
9580         POP_PARENT();
9581
9582         if (accept(T___except)) {
9583                 expression_t *const expr = parse_condition();
9584                 type_t       *      type = skip_typeref(expr->base.type);
9585                 if (is_type_integer(type)) {
9586                         type = promote_integer(type);
9587                 } else if (is_type_valid(type)) {
9588                         errorf(&expr->base.pos,
9589                                "__expect expression is not an integer, but '%T'", type);
9590                         type = type_error_type;
9591                 }
9592                 statement->ms_try.except_expression = create_implicit_cast(expr, type);
9593         } else if (!accept(T__finally)) {
9594                 parse_error_expected("while parsing __try statement", T___except, T___finally, NULL);
9595         }
9596         statement->ms_try.final_statement = parse_compound_statement(false);
9597         return statement;
9598 }
9599
9600 static statement_t *parse_empty_statement(void)
9601 {
9602         warningf(WARN_EMPTY_STATEMENT, HERE, "statement is empty");
9603         statement_t *const statement = create_empty_statement();
9604         eat(';');
9605         return statement;
9606 }
9607
9608 static statement_t *parse_local_label_declaration(void)
9609 {
9610         statement_t *statement = allocate_statement_zero(STATEMENT_DECLARATION);
9611
9612         eat(T___label__);
9613
9614         entity_t *begin   = NULL;
9615         entity_t *end     = NULL;
9616         entity_t **anchor = &begin;
9617         add_anchor_token(';');
9618         add_anchor_token(',');
9619         do {
9620                 position_t pos;
9621                 symbol_t *const symbol = expect_identifier("while parsing local label declaration", &pos);
9622                 if (symbol) {
9623                         entity_t *entity = get_entity(symbol, NAMESPACE_LABEL);
9624                         if (entity != NULL && entity->base.parent_scope == current_scope) {
9625                                 position_t const *const ppos = &entity->base.pos;
9626                                 errorf(&pos, "multiple definitions of '%N' (previous definition %P)", entity, ppos);
9627                         } else {
9628                                 entity = allocate_entity_zero(ENTITY_LOCAL_LABEL, NAMESPACE_LABEL, symbol, &pos);
9629                                 entity->base.parent_scope = current_scope;
9630
9631                                 *anchor = entity;
9632                                 anchor  = &entity->base.next;
9633                                 end     = entity;
9634
9635                                 environment_push(entity);
9636                         }
9637                 }
9638         } while (accept(','));
9639         rem_anchor_token(',');
9640         rem_anchor_token(';');
9641         expect(';');
9642         statement->declaration.declarations_begin = begin;
9643         statement->declaration.declarations_end   = end;
9644         return statement;
9645 }
9646
9647 static void parse_namespace_definition(void)
9648 {
9649         eat(T_namespace);
9650
9651         entity_t *entity = NULL;
9652         symbol_t *symbol = NULL;
9653
9654         if (token.kind == T_IDENTIFIER) {
9655                 symbol = token.base.symbol;
9656                 entity = get_entity(symbol, NAMESPACE_NORMAL);
9657                 if (entity && entity->kind != ENTITY_NAMESPACE) {
9658                         entity = NULL;
9659                         if (entity->base.parent_scope == current_scope && is_entity_valid(entity)) {
9660                                 error_redefined_as_different_kind(HERE, entity, ENTITY_NAMESPACE);
9661                         }
9662                 }
9663                 eat(T_IDENTIFIER);
9664         }
9665
9666         if (entity == NULL) {
9667                 entity = allocate_entity_zero(ENTITY_NAMESPACE, NAMESPACE_NORMAL, symbol, HERE);
9668                 entity->base.parent_scope = current_scope;
9669         }
9670
9671         if (token.kind == '=') {
9672                 /* TODO: parse namespace alias */
9673                 panic("namespace alias definition not supported yet");
9674         }
9675
9676         environment_push(entity);
9677         append_entity(current_scope, entity);
9678
9679         PUSH_SCOPE(&entity->namespacee.members);
9680         PUSH_CURRENT_ENTITY(entity);
9681
9682         add_anchor_token('}');
9683         expect('{');
9684         parse_externals();
9685         rem_anchor_token('}');
9686         expect('}');
9687
9688         POP_CURRENT_ENTITY();
9689         POP_SCOPE();
9690 }
9691
9692 /**
9693  * Parse a statement.
9694  * There's also parse_statement() which additionally checks for
9695  * "statement has no effect" warnings
9696  */
9697 static statement_t *intern_parse_statement(void)
9698 {
9699         /* declaration or statement */
9700         statement_t *statement;
9701         switch (token.kind) {
9702         case T_IDENTIFIER: {
9703                 token_kind_t la1_type = (token_kind_t)look_ahead(1)->kind;
9704                 if (la1_type == ':') {
9705                         statement = parse_label_statement();
9706                 } else if (is_typedef_symbol(token.base.symbol)) {
9707                         statement = parse_declaration_statement();
9708                 } else {
9709                         /* it's an identifier, the grammar says this must be an
9710                          * expression statement. However it is common that users mistype
9711                          * declaration types, so we guess a bit here to improve robustness
9712                          * for incorrect programs */
9713                         switch (la1_type) {
9714                         case '&':
9715                         case '*':
9716                                 if (get_entity(token.base.symbol, NAMESPACE_NORMAL) != NULL) {
9717                         default:
9718                                         statement = parse_expression_statement();
9719                                 } else {
9720                         DECLARATION_START
9721                         case T_IDENTIFIER:
9722                                         statement = parse_declaration_statement();
9723                                 }
9724                                 break;
9725                         }
9726                 }
9727                 break;
9728         }
9729
9730         case T___extension__: {
9731                 /* This can be a prefix to a declaration or an expression statement.
9732                  * We simply eat it now and parse the rest with tail recursion. */
9733                 PUSH_EXTENSION();
9734                 statement = intern_parse_statement();
9735                 POP_EXTENSION();
9736                 break;
9737         }
9738
9739         DECLARATION_START
9740                 statement = parse_declaration_statement();
9741                 break;
9742
9743         case T___label__:
9744                 statement = parse_local_label_declaration();
9745                 break;
9746
9747         case ';':         statement = parse_empty_statement();         break;
9748         case '{':         statement = parse_compound_statement(false); break;
9749         case T___leave:   statement = parse_leave_statement();         break;
9750         case T___try:     statement = parse_ms_try_statment();         break;
9751         case T_asm:       statement = parse_asm_statement();           break;
9752         case T_break:     statement = parse_break();                   break;
9753         case T_case:      statement = parse_case_statement();          break;
9754         case T_continue:  statement = parse_continue();                break;
9755         case T_default:   statement = parse_default_statement();       break;
9756         case T_do:        statement = parse_do();                      break;
9757         case T_for:       statement = parse_for();                     break;
9758         case T_goto:      statement = parse_goto();                    break;
9759         case T_if:        statement = parse_if();                      break;
9760         case T_return:    statement = parse_return();                  break;
9761         case T_switch:    statement = parse_switch();                  break;
9762         case T_while:     statement = parse_while();                   break;
9763
9764         EXPRESSION_START
9765                 statement = parse_expression_statement();
9766                 break;
9767
9768         default:
9769                 errorf(HERE, "unexpected token %K while parsing statement", &token);
9770                 statement = create_error_statement();
9771                 eat_until_anchor();
9772                 break;
9773         }
9774
9775         return statement;
9776 }
9777
9778 /**
9779  * parse a statement and emits "statement has no effect" warning if needed
9780  * (This is really a wrapper around intern_parse_statement with check for 1
9781  *  single warning. It is needed, because for statement expressions we have
9782  *  to avoid the warning on the last statement)
9783  */
9784 static statement_t *parse_statement(void)
9785 {
9786         statement_t *statement = intern_parse_statement();
9787
9788         if (statement->kind == STATEMENT_EXPRESSION) {
9789                 expression_t *expression = statement->expression.expression;
9790                 if (!expression_has_effect(expression)) {
9791                         warningf(WARN_UNUSED_VALUE, &expression->base.pos,
9792                                  "statement has no effect");
9793                 }
9794         }
9795
9796         return statement;
9797 }
9798
9799 /**
9800  * Parse a compound statement.
9801  */
9802 static statement_t *parse_compound_statement(bool inside_expression_statement)
9803 {
9804         statement_t *statement = allocate_statement_zero(STATEMENT_COMPOUND);
9805
9806         PUSH_PARENT(statement);
9807         PUSH_SCOPE(&statement->compound.scope);
9808
9809         eat('{');
9810         add_anchor_token('}');
9811         /* tokens, which can start a statement */
9812         /* TODO MS, __builtin_FOO */
9813         add_anchor_token('!');
9814         add_anchor_token('&');
9815         add_anchor_token('(');
9816         add_anchor_token('*');
9817         add_anchor_token('+');
9818         add_anchor_token('-');
9819         add_anchor_token(';');
9820         add_anchor_token('{');
9821         add_anchor_token('~');
9822         add_anchor_token(T_CHARACTER_CONSTANT);
9823         add_anchor_token(T_COLONCOLON);
9824         add_anchor_token(T_IDENTIFIER);
9825         add_anchor_token(T_MINUSMINUS);
9826         add_anchor_token(T_NUMBER);
9827         add_anchor_token(T_PLUSPLUS);
9828         add_anchor_token(T_STRING_LITERAL);
9829         add_anchor_token(T__Alignof);
9830         add_anchor_token(T__Bool);
9831         add_anchor_token(T__Complex);
9832         add_anchor_token(T__Imaginary);
9833         add_anchor_token(T__Thread_local);
9834         add_anchor_token(T___PRETTY_FUNCTION__);
9835         add_anchor_token(T___attribute__);
9836         add_anchor_token(T___builtin_va_start);
9837         add_anchor_token(T___extension__);
9838         add_anchor_token(T___func__);
9839         add_anchor_token(T___imag__);
9840         add_anchor_token(T___label__);
9841         add_anchor_token(T___real__);
9842         add_anchor_token(T_asm);
9843         add_anchor_token(T_auto);
9844         add_anchor_token(T_bool);
9845         add_anchor_token(T_break);
9846         add_anchor_token(T_case);
9847         add_anchor_token(T_char);
9848         add_anchor_token(T_class);
9849         add_anchor_token(T_const);
9850         add_anchor_token(T_const_cast);
9851         add_anchor_token(T_continue);
9852         add_anchor_token(T_default);
9853         add_anchor_token(T_delete);
9854         add_anchor_token(T_double);
9855         add_anchor_token(T_do);
9856         add_anchor_token(T_dynamic_cast);
9857         add_anchor_token(T_enum);
9858         add_anchor_token(T_extern);
9859         add_anchor_token(T_false);
9860         add_anchor_token(T_float);
9861         add_anchor_token(T_for);
9862         add_anchor_token(T_goto);
9863         add_anchor_token(T_if);
9864         add_anchor_token(T_inline);
9865         add_anchor_token(T_int);
9866         add_anchor_token(T_long);
9867         add_anchor_token(T_new);
9868         add_anchor_token(T_operator);
9869         add_anchor_token(T_register);
9870         add_anchor_token(T_reinterpret_cast);
9871         add_anchor_token(T_restrict);
9872         add_anchor_token(T_return);
9873         add_anchor_token(T_short);
9874         add_anchor_token(T_signed);
9875         add_anchor_token(T_sizeof);
9876         add_anchor_token(T_static);
9877         add_anchor_token(T_static_cast);
9878         add_anchor_token(T_struct);
9879         add_anchor_token(T_switch);
9880         add_anchor_token(T_template);
9881         add_anchor_token(T_this);
9882         add_anchor_token(T_throw);
9883         add_anchor_token(T_true);
9884         add_anchor_token(T_try);
9885         add_anchor_token(T_typedef);
9886         add_anchor_token(T_typeid);
9887         add_anchor_token(T_typename);
9888         add_anchor_token(T_typeof);
9889         add_anchor_token(T_union);
9890         add_anchor_token(T_unsigned);
9891         add_anchor_token(T_using);
9892         add_anchor_token(T_void);
9893         add_anchor_token(T_volatile);
9894         add_anchor_token(T_wchar_t);
9895         add_anchor_token(T_while);
9896
9897         statement_t **anchor            = &statement->compound.statements;
9898         bool          only_decls_so_far = true;
9899         while (token.kind != '}' && token.kind != T_EOF) {
9900                 statement_t *sub_statement = intern_parse_statement();
9901                 if (sub_statement->kind == STATEMENT_ERROR) {
9902                         break;
9903                 }
9904
9905                 if (sub_statement->kind != STATEMENT_DECLARATION) {
9906                         only_decls_so_far = false;
9907                 } else if (!only_decls_so_far) {
9908                         position_t const *const pos = &sub_statement->base.pos;
9909                         warningf(WARN_DECLARATION_AFTER_STATEMENT, pos, "ISO C90 forbids mixed declarations and code");
9910                 }
9911
9912                 *anchor = sub_statement;
9913                 anchor  = &sub_statement->base.next;
9914         }
9915         expect('}');
9916
9917         /* look over all statements again to produce no effect warnings */
9918         if (is_warn_on(WARN_UNUSED_VALUE)) {
9919                 statement_t *sub_statement = statement->compound.statements;
9920                 for (; sub_statement != NULL; sub_statement = sub_statement->base.next) {
9921                         if (sub_statement->kind != STATEMENT_EXPRESSION)
9922                                 continue;
9923                         /* don't emit a warning for the last expression in an expression
9924                          * statement as it has always an effect */
9925                         if (inside_expression_statement && sub_statement->base.next == NULL)
9926                                 continue;
9927
9928                         expression_t *expression = sub_statement->expression.expression;
9929                         if (!expression_has_effect(expression)) {
9930                                 warningf(WARN_UNUSED_VALUE, &expression->base.pos,
9931                                          "statement has no effect");
9932                         }
9933                 }
9934         }
9935
9936         rem_anchor_token(T_while);
9937         rem_anchor_token(T_wchar_t);
9938         rem_anchor_token(T_volatile);
9939         rem_anchor_token(T_void);
9940         rem_anchor_token(T_using);
9941         rem_anchor_token(T_unsigned);
9942         rem_anchor_token(T_union);
9943         rem_anchor_token(T_typeof);
9944         rem_anchor_token(T_typename);
9945         rem_anchor_token(T_typeid);
9946         rem_anchor_token(T_typedef);
9947         rem_anchor_token(T_try);
9948         rem_anchor_token(T_true);
9949         rem_anchor_token(T_throw);
9950         rem_anchor_token(T_this);
9951         rem_anchor_token(T_template);
9952         rem_anchor_token(T_switch);
9953         rem_anchor_token(T_struct);
9954         rem_anchor_token(T_static_cast);
9955         rem_anchor_token(T_static);
9956         rem_anchor_token(T_sizeof);
9957         rem_anchor_token(T_signed);
9958         rem_anchor_token(T_short);
9959         rem_anchor_token(T_return);
9960         rem_anchor_token(T_restrict);
9961         rem_anchor_token(T_reinterpret_cast);
9962         rem_anchor_token(T_register);
9963         rem_anchor_token(T_operator);
9964         rem_anchor_token(T_new);
9965         rem_anchor_token(T_long);
9966         rem_anchor_token(T_int);
9967         rem_anchor_token(T_inline);
9968         rem_anchor_token(T_if);
9969         rem_anchor_token(T_goto);
9970         rem_anchor_token(T_for);
9971         rem_anchor_token(T_float);
9972         rem_anchor_token(T_false);
9973         rem_anchor_token(T_extern);
9974         rem_anchor_token(T_enum);
9975         rem_anchor_token(T_dynamic_cast);
9976         rem_anchor_token(T_do);
9977         rem_anchor_token(T_double);
9978         rem_anchor_token(T_delete);
9979         rem_anchor_token(T_default);
9980         rem_anchor_token(T_continue);
9981         rem_anchor_token(T_const_cast);
9982         rem_anchor_token(T_const);
9983         rem_anchor_token(T_class);
9984         rem_anchor_token(T_char);
9985         rem_anchor_token(T_case);
9986         rem_anchor_token(T_break);
9987         rem_anchor_token(T_bool);
9988         rem_anchor_token(T_auto);
9989         rem_anchor_token(T_asm);
9990         rem_anchor_token(T___real__);
9991         rem_anchor_token(T___label__);
9992         rem_anchor_token(T___imag__);
9993         rem_anchor_token(T___func__);
9994         rem_anchor_token(T___extension__);
9995         rem_anchor_token(T___builtin_va_start);
9996         rem_anchor_token(T___attribute__);
9997         rem_anchor_token(T___PRETTY_FUNCTION__);
9998         rem_anchor_token(T__Thread_local);
9999         rem_anchor_token(T__Imaginary);
10000         rem_anchor_token(T__Complex);
10001         rem_anchor_token(T__Bool);
10002         rem_anchor_token(T__Alignof);
10003         rem_anchor_token(T_STRING_LITERAL);
10004         rem_anchor_token(T_PLUSPLUS);
10005         rem_anchor_token(T_NUMBER);
10006         rem_anchor_token(T_MINUSMINUS);
10007         rem_anchor_token(T_IDENTIFIER);
10008         rem_anchor_token(T_COLONCOLON);
10009         rem_anchor_token(T_CHARACTER_CONSTANT);
10010         rem_anchor_token('~');
10011         rem_anchor_token('{');
10012         rem_anchor_token(';');
10013         rem_anchor_token('-');
10014         rem_anchor_token('+');
10015         rem_anchor_token('*');
10016         rem_anchor_token('(');
10017         rem_anchor_token('&');
10018         rem_anchor_token('!');
10019         rem_anchor_token('}');
10020
10021         POP_SCOPE();
10022         POP_PARENT();
10023         return statement;
10024 }
10025
10026 /**
10027  * Check for unused global static functions and variables
10028  */
10029 static void check_unused_globals(void)
10030 {
10031         if (!is_warn_on(WARN_UNUSED_FUNCTION) && !is_warn_on(WARN_UNUSED_VARIABLE))
10032                 return;
10033
10034         for (const entity_t *entity = file_scope->entities; entity != NULL;
10035              entity = entity->base.next) {
10036                 if (!is_declaration(entity))
10037                         continue;
10038
10039                 const declaration_t *declaration = &entity->declaration;
10040                 if (declaration->used                  ||
10041                     declaration->modifiers & DM_UNUSED ||
10042                     declaration->modifiers & DM_USED   ||
10043                     declaration->storage_class != STORAGE_CLASS_STATIC)
10044                         continue;
10045
10046                 warning_t   why;
10047                 char const *s;
10048                 if (entity->kind == ENTITY_FUNCTION) {
10049                         /* inhibit warning for static inline functions */
10050                         if (entity->function.is_inline)
10051                                 continue;
10052
10053                         why = WARN_UNUSED_FUNCTION;
10054                         s   = entity->function.body != NULL ? "defined" : "declared";
10055                 } else {
10056                         why = WARN_UNUSED_VARIABLE;
10057                         s   = "defined";
10058                 }
10059
10060                 warningf(why, &declaration->base.pos, "'%#N' %s but not used", entity, s);
10061         }
10062 }
10063
10064 static void parse_global_asm(void)
10065 {
10066         statement_t *statement = allocate_statement_zero(STATEMENT_ASM);
10067
10068         eat(T_asm);
10069         add_anchor_token(';');
10070         add_anchor_token(')');
10071         add_anchor_token(T_STRING_LITERAL);
10072         expect('(');
10073
10074         rem_anchor_token(T_STRING_LITERAL);
10075         statement->asms.asm_text = parse_string_literals("global asm");
10076         statement->base.next     = unit->global_asm;
10077         unit->global_asm         = statement;
10078
10079         rem_anchor_token(')');
10080         expect(')');
10081         rem_anchor_token(';');
10082         expect(';');
10083 }
10084
10085 static void parse_linkage_specification(void)
10086 {
10087         eat(T_extern);
10088
10089         position_t  const pos     = *HERE;
10090         char const *const linkage = parse_string_literals(NULL).begin;
10091
10092         linkage_kind_t old_linkage = current_linkage;
10093         linkage_kind_t new_linkage;
10094         if (streq(linkage, "C")) {
10095                 new_linkage = LINKAGE_C;
10096         } else if (streq(linkage, "C++")) {
10097                 new_linkage = LINKAGE_CXX;
10098         } else {
10099                 errorf(&pos, "linkage string \"%s\" not recognized", linkage);
10100                 new_linkage = LINKAGE_C;
10101         }
10102         current_linkage = new_linkage;
10103
10104         if (accept('{')) {
10105                 parse_externals();
10106                 expect('}');
10107         } else {
10108                 parse_external();
10109         }
10110
10111         assert(current_linkage == new_linkage);
10112         current_linkage = old_linkage;
10113 }
10114
10115 static void parse_external(void)
10116 {
10117         switch (token.kind) {
10118                 case T_extern:
10119                         if (look_ahead(1)->kind == T_STRING_LITERAL) {
10120                                 parse_linkage_specification();
10121                         } else {
10122                 DECLARATION_START_NO_EXTERN
10123                 case T_IDENTIFIER:
10124                 case T___extension__:
10125                 /* tokens below are for implicit int */
10126                 case '&':  /* & x; -> int& x; (and error later, because C++ has no
10127                               implicit int) */
10128                 case '*':  /* * x; -> int* x; */
10129                 case '(':  /* (x); -> int (x); */
10130                                 PUSH_EXTENSION();
10131                                 parse_external_declaration();
10132                                 POP_EXTENSION();
10133                         }
10134                         return;
10135
10136                 case T_asm:
10137                         parse_global_asm();
10138                         return;
10139
10140                 case T_namespace:
10141                         parse_namespace_definition();
10142                         return;
10143
10144                 case ';':
10145                         if (!strict_mode) {
10146                                 warningf(WARN_STRAY_SEMICOLON, HERE, "stray ';' outside of function");
10147                                 eat(';');
10148                                 return;
10149                         }
10150                         /* FALLTHROUGH */
10151
10152                 default:
10153                         errorf(HERE, "stray %K outside of function", &token);
10154                         if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10155                                 eat_until_matching_token(token.kind);
10156                         next_token();
10157                         return;
10158         }
10159 }
10160
10161 static void parse_externals(void)
10162 {
10163         add_anchor_token('}');
10164         add_anchor_token(T_EOF);
10165
10166 #ifndef NDEBUG
10167         /* make a copy of the anchor set, so we can check if it is restored after parsing */
10168         unsigned short token_anchor_copy[T_LAST_TOKEN];
10169         memcpy(token_anchor_copy, token_anchor_set, sizeof(token_anchor_copy));
10170 #endif
10171
10172         while (token.kind != T_EOF && token.kind != '}') {
10173 #ifndef NDEBUG
10174                 for (int i = 0; i < T_LAST_TOKEN; ++i) {
10175                         unsigned short count = token_anchor_set[i] - token_anchor_copy[i];
10176                         if (count != 0) {
10177                                 /* the anchor set and its copy differs */
10178                                 internal_errorf(HERE, "Leaked anchor token %k %d times", i, count);
10179                         }
10180                 }
10181                 if (in_gcc_extension) {
10182                         /* an gcc extension scope was not closed */
10183                         internal_errorf(HERE, "Leaked __extension__");
10184                 }
10185 #endif
10186
10187                 parse_external();
10188         }
10189
10190         rem_anchor_token(T_EOF);
10191         rem_anchor_token('}');
10192 }
10193
10194 /**
10195  * Parse a translation unit.
10196  */
10197 static void parse_translation_unit(void)
10198 {
10199         add_anchor_token(T_EOF);
10200
10201         while (true) {
10202                 parse_externals();
10203
10204                 if (token.kind == T_EOF)
10205                         break;
10206
10207                 errorf(HERE, "stray %K outside of function", &token);
10208                 if (token.kind == '(' || token.kind == '{' || token.kind == '[')
10209                         eat_until_matching_token(token.kind);
10210                 next_token();
10211         }
10212 }
10213
10214 void set_default_visibility(elf_visibility_tag_t visibility)
10215 {
10216         default_visibility = visibility;
10217 }
10218
10219 /**
10220  * Parse the input.
10221  *
10222  * @return  the translation unit or NULL if errors occurred.
10223  */
10224 void start_parsing(void)
10225 {
10226         environment_stack = NEW_ARR_F(stack_entry_t, 0);
10227         label_stack       = NEW_ARR_F(stack_entry_t, 0);
10228
10229         print_to_file(stderr);
10230
10231         assert(unit == NULL);
10232         unit = allocate_ast_zero(sizeof(unit[0]));
10233
10234         assert(file_scope == NULL);
10235         file_scope = &unit->scope;
10236
10237         assert(current_scope == NULL);
10238         scope_push(&unit->scope);
10239
10240         create_gnu_builtins();
10241         if (c_mode & _MS)
10242                 create_microsoft_intrinsics();
10243 }
10244
10245 translation_unit_t *finish_parsing(void)
10246 {
10247         assert(current_scope == &unit->scope);
10248         scope_pop(NULL);
10249
10250         assert(file_scope == &unit->scope);
10251         check_unused_globals();
10252         file_scope = NULL;
10253
10254         DEL_ARR_F(environment_stack);
10255         DEL_ARR_F(label_stack);
10256
10257         translation_unit_t *result = unit;
10258         unit = NULL;
10259         return result;
10260 }
10261
10262 /* §6.9.2:2 and §6.9.2:5: At the end of the translation incomplete arrays
10263  * are given length one. */
10264 static void complete_incomplete_arrays(void)
10265 {
10266         size_t n = ARR_LEN(incomplete_arrays);
10267         for (size_t i = 0; i != n; ++i) {
10268                 declaration_t *const decl = incomplete_arrays[i];
10269                 type_t        *const type = skip_typeref(decl->type);
10270
10271                 if (!is_type_incomplete(type))
10272                         continue;
10273
10274                 position_t const *const pos = &decl->base.pos;
10275                 warningf(WARN_OTHER, pos, "array '%#N' assumed to have one element", (entity_t const*)decl);
10276
10277                 type_t *const new_type = duplicate_type(type);
10278                 new_type->array.size_constant     = true;
10279                 new_type->array.has_implicit_size = true;
10280                 new_type->array.size              = 1;
10281
10282                 type_t *const result = identify_new_type(new_type);
10283
10284                 decl->type = result;
10285         }
10286 }
10287
10288 static void prepare_main_collect2(entity_t *const entity)
10289 {
10290         PUSH_SCOPE(&entity->function.body->compound.scope);
10291
10292         // create call to __main
10293         symbol_t *symbol         = symbol_table_insert("__main");
10294         entity_t *subsubmain_ent
10295                 = create_implicit_function(symbol, &builtin_position);
10296
10297         expression_t *ref     = allocate_expression_zero(EXPR_REFERENCE);
10298         type_t       *ftype   = subsubmain_ent->declaration.type;
10299         ref->base.pos         = builtin_position;
10300         ref->base.type        = make_pointer_type(ftype, TYPE_QUALIFIER_NONE);
10301         ref->reference.entity = subsubmain_ent;
10302
10303         expression_t *call  = allocate_expression_zero(EXPR_CALL);
10304         call->base.pos      = builtin_position;
10305         call->base.type     = type_void;
10306         call->call.function = ref;
10307
10308         statement_t *expr_statement = allocate_statement_zero(STATEMENT_EXPRESSION);
10309         expr_statement->base.pos              = builtin_position;
10310         expr_statement->expression.expression = call;
10311
10312         statement_t *const body = entity->function.body;
10313         assert(body->kind == STATEMENT_COMPOUND);
10314         compound_statement_t *compounds = &body->compound;
10315
10316         expr_statement->base.next = compounds->statements;
10317         compounds->statements     = expr_statement;
10318
10319         POP_SCOPE();
10320 }
10321
10322 void parse(void)
10323 {
10324         lookahead_bufpos = 0;
10325         for (int i = 0; i < MAX_LOOKAHEAD + 2; ++i) {
10326                 next_token();
10327         }
10328         current_linkage   = c_mode & _CXX ? LINKAGE_CXX : LINKAGE_C;
10329         incomplete_arrays = NEW_ARR_F(declaration_t*, 0);
10330         parse_translation_unit();
10331         complete_incomplete_arrays();
10332         DEL_ARR_F(incomplete_arrays);
10333         incomplete_arrays = NULL;
10334 }
10335
10336 /**
10337  * Initialize the parser.
10338  */
10339 void init_parser(void)
10340 {
10341         memset(token_anchor_set, 0, sizeof(token_anchor_set));
10342
10343         init_expression_parsers();
10344         obstack_init(&temp_obst);
10345 }
10346
10347 /**
10348  * Terminate the parser.
10349  */
10350 void exit_parser(void)
10351 {
10352         obstack_free(&temp_obst, NULL);
10353 }